WO2024242433A1 - Optical device for aligning wafer - Google Patents

Abstract

An optical device for aligning a wafer is disclosed. The optical device for aligning a wafer, according to one aspect of the present invention, aligns a contact probe with a wafer facing the contact probe, and comprises: a camera disposed between the contact probe and the wafer so as to face a first direction, which is parallel to the floor surface and is perpendicular to the direction in which the contact probe faces the wafer; a camera moving module for moving the camera such that the camera moves in the first direction; a light-emitting unit coupled to the camera so as to emit light in the same direction as the direction in which the camera faces between the contact probe and the wafer; a first reflection unit, which is positioned at one position in front of the camera and reflects the light emitted from the light-emitting unit such that the light can reach the contact probe; and a second reflection unit, which is positioned at another position in front of the camera and reflects the light emitted from the light-emitting unit such that the light can reach the wafer, wherein the camera, the light-emitting unit, the first reflection unit and the second reflection unit are arranged such that a portion of the light emitted from the light-emitting unit is reflected by the first reflection unit and reaches the contact probe, the light reflected from the contact probe passes through the first reflection unit again to form an image on the camera, the remaining portion of the light emitted from the light-emitting unit is reflected by the second reflection unit and reaches the wafer, and the light reflected from the wafer passes through the second reflection unit again so that an image on the camera can be formed.

Description

Optical device for wafer alignment

The present invention relates to an optical device for wafer alignment, and more particularly, to an optical device for wafer alignment that can be used for aligning a contact probe and a wafer.

A conventional prober is configured to align the probe and the wafer by having a contact probe camera that photographs the contact probe and a wafer camera that photographs the wafer.

At this time, the chuck on which the wafer is fixed moves to acquire images from each of the contact probe camera and the wafer camera, and probing is performed by moving the chuck again to the probing position calculated from the two images.

At this time, the distance required for the chuck to move again to the probing position calculated from the two images is considerable, and movement errors occur due to thermal deformation of the wafer that occurs during the chuck movement time.

To solve these problems, there is a need to develop an optical device for wafer alignment that can move instead of the chuck to take images of the contact probe and the wafer respectively, so that the chuck can move a short distance.

The present invention is intended to solve the above problems, and an object of the present invention is to provide an optical device for wafer alignment that moves instead of a chuck so that the chuck can move a short distance in the process of aligning a contact probe and a wafer.

Another object of the present invention is to provide an optical device for wafer alignment configured to align a wafer using one camera.

The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

According to one aspect of the present invention, there is provided an optical device for wafer alignment for aligning a contact probe and a wafer facing the contact probe, the optical device comprising: a camera positioned between the contact probe and the wafer so as to face a first direction that is perpendicular to the direction in which the contact probe and the wafer face each other and is horizontal to a floor surface; a camera movement module that moves the camera so that the camera moves along the first direction; a light emitting unit coupled to the camera and irradiating light between the contact probe and the wafer in the same direction as the direction in which the camera faces; a first reflector positioned at a position in front of the camera and reflecting the light irradiated from the light emitting unit so that the light can reach the contact probe; A wafer alignment optical device is provided, in which the camera, the light emitting unit, the first reflector and the second reflector are arranged such that the light radiated from the light emitting unit is reflected by the first reflector and reaches the contact probe, the light reflected from the contact probe passes through the first reflector again and is imaged on the camera, and the remaining part of the light radiated from the light emitting unit is reflected by the second reflector and reaches the wafer, and the light reflected from the wafer passes through the second reflector again and is imaged on the camera.

At this time, the first reflector is arranged to be inclined at a first angle with respect to the floor surface, and the second reflector is arranged to be inclined at a second angle with respect to the floor surface, and the first angle and the second angle are the same, but the first reflector and the second reflector may not be parallel.

In addition, the first reflector may be a half mirror that transmits a portion of the irradiated light and reflects the remaining portion, or a beam splitter that changes the path of travel of a portion of the irradiated light, and the light reaching the second reflector may be irradiated from the irradiator and then passes through the first reflector to reach the second reflector, such that the irradiator, the first reflector, and the second reflector may be arranged in a row.

At this time, the camera may be a polarizing camera having both a P-wave photodetector and an S-wave photodetector, the light irradiated by the light emitting unit may be unpolarized light, and the first reflector may be a polarizing beam splitter.

Additionally, the camera may be a color camera, the light irradiated by the light emitting unit may be white light, and the first reflector may be a dichroic beam splitter.

At this time, the camera may be a polarizing camera having both a P-wave photodetector and an S-wave photodetector, the light irradiated by the light emitting unit may be light that irradiates P-wave polarization and S-wave polarization simultaneously at different intensities, and the first reflector may be a polarizing beam splitter.

In addition, the camera may be a color camera, the light irradiated by the light emitting unit may be light irradiated simultaneously with different intensities from two different colored light sources, and the first reflector may be a dichroic beam splitter.

At this time, the camera may be a black and white camera, the light irradiated by the light emitting unit may be light irradiated by alternating P-wave polarization and S-wave polarization, and the first reflector may be a polarizing beam splitter.

In addition, the second reflector may be a half mirror that transmits a portion of the irradiated light and reflects the remaining portion, or a beam splitter that changes the path of travel of a portion of the irradiated light, and the light reaching the first reflector may be irradiated from the irradiator and then passes through the second reflector to reach the first reflector, so that the irradiator, the second reflector, and the first reflector may be arranged in a row.

At this time, the camera may be a polarizing camera having both a P-wave photodetector and an S-wave photodetector, the light irradiated by the light emitting unit may be unpolarized light, and the first reflector may be a polarizing beam splitter.

Additionally, the camera may be a color camera, the light irradiated by the light emitting unit may be white light, and the first reflector may be a dichroic beam splitter.

At this time, the camera may be a polarizing camera having both a P-wave photodetector and an S-wave photodetector, the light irradiated by the light emitting unit may be light that irradiates P-wave polarization and S-wave polarization simultaneously at different intensities, and the first reflector may be a polarizing beam splitter.

In addition, the camera may be a color camera, the light irradiated by the light emitting unit may be light irradiated simultaneously with different intensities from two different colored light sources, and the first reflector may be a dichroic beam splitter.

At this time, the camera may be a black and white camera, the light irradiated by the light emitting unit may be light irradiated by alternating P-wave polarization and S-wave polarization, and the first reflector may be a polarizing beam splitter.

In addition, the second reflector is positioned below the first reflector when viewed in the vertical direction, and the light emitting unit can irradiate light to each of the first reflector and the second reflector.

At this time, each of the first reflector and the second reflector may be a mirror.

Additionally, the first reflector may include a first surface formed on one prism, and the second reflector may include a second surface formed on the one prism and adjacent to the first surface.

According to the above configuration, the optical device for wafer alignment according to an embodiment of the present invention can move instead of the chuck to allow the chuck to move a short distance in the process of aligning the contact probe and the wafer.

An optical device for wafer alignment according to an embodiment of the present invention can align a wafer using one camera.

It should be understood that the effects of the present invention are not limited to the effects described above, but include all effects that can be inferred from the composition of the invention described in the detailed description or claims of the present invention.

Figure 1 is a configuration diagram of an optical device and a prober according to conventional technology.

FIG. 2 is a configuration diagram of an optical device and a prober according to one embodiment of the present invention.

Figure 3 is a configuration diagram of an optical device according to the first embodiment of the present invention.

Figure 4 is a configuration diagram of an optical device according to a second embodiment of the present invention.

Figure 5 is a configuration diagram of an optical device according to a third embodiment of the present invention.

Figure 6 is a configuration diagram of an optical device according to the fourth embodiment of the present invention.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those with ordinary skill in the art can easily practice the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein. In order to clearly describe the present invention, parts that are not related to the description are omitted in the drawings, and the same reference numerals are assigned to the same or similar components throughout the specification.

The words and terms used in this specification and claims should not be construed as limited to their usual or dictionary meanings, but should be interpreted as having meanings and concepts consistent with the technical idea of the present invention, in accordance with the principles by which the inventor can define terms and concepts in order to best describe his or her invention.

Therefore, the embodiments described in this specification and the configurations illustrated in the drawings correspond to preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, so that the corresponding configurations may have various equivalents and modified examples that can replace them at the time of filing of the present invention.

In the following description, descriptions of some components may be omitted to clarify the features of the present invention.

In this specification, it should be understood that terms such as “include” or “have” are intended to describe the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

In order to clearly express the features of the configuration in the drawing, the thickness and size are exaggerated, and the thickness and size of the configuration shown in the drawing are not necessarily the same as in reality.

In the following description of the drawings, each direction is defined based on the coordinate axes illustrated in Fig. 2. More specifically, the positive direction of the z-axis is defined as the upper side, and the negative direction of the z-axis is defined as the lower side. The positive direction of the x-axis is defined as the right side, and the negative direction of the x-axis is defined as the left side.

FIG. 1 is a configuration diagram of an optical device (200, 300) and a prober (1000) according to a prior art, and FIG. 2 is a configuration diagram of an optical device (200) for wafer alignment and a prober (10) according to a first embodiment of the present invention.

Referring to FIG. 1, a prober (1000) according to the prior art includes a probe card (1100), a first optical device (1200), a second optical device (1300), a wafer (1400), and a chuck (1500).

The prober (1000) is a semiconductor inspection device that inspects the electrical characteristics of semiconductor elements formed on a wafer (1400) on which all semiconductor preprocessing has been completed before the wafer (1400) enters the post-processing stage to confirm the presence or absence of defects.

In a semiconductor wafer (1400) on which a plurality of semiconductor elements are formed, a prober (1000) is used as a wafer (1400) inspection device to inspect the electrical characteristics of each semiconductor element.

Referring to FIG. 1, the prober (1000) is provided with a disc-shaped probe card (1100) facing the wafer (1400) on the upper side of the wafer (1400), i.e., in the positive direction of the z-axis, and the probe card (1100) may be provided with a plurality of contact probes (1110), which are contact terminals arranged to face each electrode pad or each solder bump of a semiconductor element of the wafer (1400).

At this time, the wafer (1400) is fixed to the upper side of the chuck (1500) and the chuck (1500) moves so that alignment of the contact probe (1110) and the wafer (1400) can be achieved.

Specifically, referring to FIG. 1, a first optical device (1200) fixed to the right end of a probe card (1100) to check the position of a wafer (1400) and a second optical device (1300) fixed to the left end of a chuck (1500) to check the position of a contact probe (1110) can obtain images of each of the wafer (1400) and the contact probe (1110) while the chuck (1500) moves in a state where the probe card (1100) is fixed.

The chuck (1500) is moved to the probing position calculated from the image acquired in this manner to align the contact probe (1110) and the wafer (1400).

At this time, during the process of acquiring an image through the first optical device (1200) and the second optical device (1300) and aligning the contact probe (1110) and the wafer (1400), an alignment error occurs between the contact probe (110) and the wafer (400) due to causes such as thermal deformation of the wafer (1400) caused by the heat of the chuck (1500) while the chuck (1500) moves.

To solve this problem, referring to FIG. 2, a prober (10) according to one embodiment of the present invention may include a probe card (100), an optical device for wafer alignment (200), a wafer (400), and a chuck (500).

The prober (10) according to one embodiment of the present invention is a prober (1000) according to the prior art, with only the optical device (1200, 1300) changed. Hereinafter, the optical device (200) for wafer alignment provided in the prober (10) according to one embodiment of the present invention will be described.

At this time, the optical device (200) for wafer alignment equipped in the prober (10) according to one embodiment of the present invention may be formed as an optical device (200) for wafer alignment formed integrally, unlike the optical devices (1200, 1300) of the conventional prober (1000) which are formed as a first optical device (1200) and a second optical device (1300).

In addition, the optical device (200) for wafer alignment can obtain images of the contact probe (110) and the wafer (400) without being connected to each of the probe card (100) and the chuck (500).

Referring to FIG. 2, an optical device (200) for wafer alignment can be placed at the bottom of the probe card (100) and the top of the wafer (400).

At this time, the optical device (200) for wafer alignment moves in a direction parallel to the x-axis between the probe card (100) and the wafer (400) and can acquire an image of the contact probe (110) formed under the probe card (100) and the wafer (400). A specific image acquisition method is described below.

FIG. 3 is a configuration diagram of an optical device (200) for wafer alignment according to a first embodiment of the present invention, and FIG. 4 is a configuration diagram of an optical device (200') for wafer alignment according to a second embodiment of the present invention.

Referring to FIG. 3, an optical device (200) for wafer alignment according to the first embodiment of the present invention may include a light emitting unit (210), a first reflecting unit (220), a second reflecting unit (230), a camera (240), and a camera movement module (250).

At this time, referring to FIGS. 2 and 3, the camera (240) is positioned between the contact probe (110) and the wafer (400) and can be positioned to face the positive direction of the x-axis.

The camera (240) may be of any type, including a color camera, a black and white camera, or a polarizing camera.

Meanwhile, the camera (240) may be coupled with a light emitting unit (210) that irradiates light in a direction parallel to the direction in which the camera (240) is facing.

At this time, the light irradiated by the light emitting unit (210) is irradiated in the positive direction of the x-axis along the first path (211).

The light emitted by the light emitting unit (210) may be polarized or unpolarized light.

Additionally, the light emitted by the light emitting unit (210) may be white light, and there may be no limitation on the type of light.

At this time, the light emitting unit (210) may irradiate two or more types of light simultaneously, such as irradiating P-wave polarization and S-wave polarization simultaneously, or irradiating two different colors of light simultaneously.

In addition, when the light emitting unit (210) irradiates two or more types of light, the intensity of each type of light can be irradiated differently, and different types of light can be irradiated alternately.

Referring to FIG. 3, light irradiated along the first path (211) is irradiated from the light emitting portion (210) to the first reflecting portion (220) positioned in the positive direction of the x-axis.

At this time, the first reflector (220) may be positioned to be inclined at a first angle (θ1) with respect to the positive direction of the x-axis, and the first reflector (220) may be a half mirror that transmits a portion of the irradiated light and reflects the remaining portion, or a beam splitter that changes the travel path of a portion of the irradiated light.

More specifically, the first reflector (220) may be formed as a polarizing beam splitter or a dichroic beam splitter.

Accordingly, referring to FIGS. 2 and 3, some of the light reflected from the first reflector (220) among the light irradiated along the first path (211) can reach the contact probe (110) along the second path (212) at an incident angle of the third angle (θ3).

At this time, the light that reaches the contact probe (110) with an incident angle of the third angle (θ3) must be reflected from the contact probe (110) with a reflection angle of the third angle (θ3) and sequentially reach the camera (240) again along the second path (212) and the first path (211). Therefore, in the first embodiment of the present invention, the third angle (θ3) may be 90 degrees.

Meanwhile, the remaining light that is not reflected from the light irradiated along the first path (211) can be reflected from the second reflector (230) located in the positive direction of the x-axis from the first reflector (220) along the third path (213).

At this time, the second reflector (230) can be positioned to be tilted at a second angle (θ2) with respect to the negative direction of the x-axis.

Additionally, the second reflector (220) may be a mirror that reflects all of the light being irradiated.

At this time, the first reflector (220) and the second reflector (230) can be arranged so that the first angle (θ1) and the second angle (θ2) are equal.

Additionally, the first angle (θ1) and the second angle (θ2) can be 45 degrees.

Accordingly, referring to FIGS. 2 and 3, light irradiated along the third path (213) can be reflected by the second reflector (230) and reach the wafer (400) along the fourth path (214) at an incident angle of the fourth angle (θ4).

At this time, light that reaches the wafer (400) with an incident angle of the fourth angle (θ4) must be reflected from the wafer (400) with a reflection angle of the fourth angle (θ4) and sequentially reach the camera (240) again along the fourth path (214), the third path (213), and the first path (211). Therefore, in the first embodiment of the present invention, the fourth angle (θ4) may be 90 degrees.

Therefore, the optical device (200) for wafer alignment according to the first embodiment of the present invention can simultaneously acquire images of the lower part of the contact probe (110) and the upper part of the wafer (400) using one camera (240) based on the above principle.

For example, the light emitting unit (210) may irradiate unpolarized light, the first reflecting unit (220) may be a polarizing beam splitter, and the camera (240) may be a polarizing camera having both a P-wave receiving pixel and an S-wave receiving pixel.

At this time, the investigated light source is separated into P-wave polarization and S-wave polarization by the first reflector (220) and can reach the contact probe (110) and wafer (400), respectively.

All of the light reflected from each of the contact probe (110) and the wafer (400) is received by the camera (240), and the camera (240) is a polarization camera that has both a P-wave receiving pixel and an S-wave receiving pixel, so that it is possible to acquire two images simultaneously.

In addition, the intensity of light irradiated to the contact probe (110) should generally be stronger than the intensity of light irradiated to the wafer (400). In this case, if the intensity of the light source irradiating the contact probe (110) and the wafer (400) should be different, the light emitting unit (210) can irradiate P-wave polarization and S-wave polarization at the same time with different intensities.

As another example, the light emitting unit (210) may irradiate white light, the first reflecting unit (220) may be a dichroic beam splitter, and the camera (240) may be a color camera.

At this time, the investigated light source is separated into two different color lights by the first reflector (210) and can reach the contact probe (110) and the wafer (400) respectively.

The light reflected from each of the contact probe (110) and the wafer (400) is received by the camera (240), and the camera (240) is a color camera with two different color pixels, so it is possible to acquire two images simultaneously.

In addition, the intensity of light irradiated to the contact probe (110) should generally be stronger than the intensity of light irradiated to the wafer (400). In this case, if the intensities of the light sources irradiating the contact probe (110) and the wafer (400) should be different, the light emitting unit (210) can irradiate two different color lights at different intensities simultaneously.

As another example, the light emitting unit (210) may alternately irradiate P-wave polarization and S-wave polarization, the first reflecting unit (220) may be a polarizing beam splitter, and the camera (240) may be a general black-and-white camera.

In general, the intensity of light irradiated to the contact probe (110) should be stronger than the intensity of light irradiated to the wafer (400). In this case, when the intensity of light sources irradiated to the contact probe (110) and the wafer (400) should be different, the light emitting unit (210) can selectively irradiate P-wave polarization and S-wave polarization to irradiate the intensities of the two light sources differently.

At this time, using a regular black and white camera can have the advantage of a wider range of choices compared to a polarizing camera.

Meanwhile, the camera movement module (250) may be a movement module that moves not only the camera (240) but also the light emitting unit (210), the first reflector (220) and the second reflector (230).

At this time, there may be no restrictions on the movement method, shape, etc. of the camera movement module (250).

Referring to FIGS. 2 and 3, the camera movement module (250) can move the optical device (200) for wafer alignment in a direction parallel to the x-axis between the probe card (100) and the wafer (400) as described above.

That is, the camera movement module (250) can move not only the camera (240), but also the light emitting unit (210), the first reflecting unit (220), and the second reflecting unit (230) in a direction parallel to the x-axis between the probe card (100) and the wafer (400).

At this time, the optical device (200) for wafer alignment is moved by the camera movement module (250) and can obtain images of the lower part of the contact probe (110) and the upper part of the wafer (400).

Unlike the conventional prober (1000) in which the chuck (1500) moves to obtain an image of the lower portion of the contact probe (1110) and the upper portion of the wafer (1500), in the prober (10) equipped with the optical device (200) for wafer alignment according to the first embodiment of the present invention, the optical device (200) for wafer alignment moves to obtain an image of the contact probe (110) and the wafer (400), so the movement distance of the chuck (500) required in the process of aligning the contact probe (110) and the wafer (400) can be significantly reduced.

Therefore, the prober (10) equipped with the optical device (200) for wafer alignment according to the first embodiment of the present invention can significantly reduce the movement distance of the chuck (500) required in the process of aligning the contact probe (110) and the wafer (400) compared to the prober (1000) according to the prior art, and thus can reduce the alignment error between the contact probe (110) and the wafer (400) caused by the movement of the chuck (500).

The second embodiment is a modified embodiment of the first embodiment. Below, descriptions of the same configurations among the configurations of the second embodiment as those of the first embodiment will be omitted, and descriptions will be made mainly of configurations that are different from those of the first embodiment.

Referring to FIG. 4, an optical device (200') for wafer alignment according to the second embodiment of the present invention may include a light emitting unit (210), a first reflecting unit (220'), a second reflecting unit (230'), a camera (240), and a camera movement module (250).

Specifically, in the optical device (200') for wafer alignment according to the second embodiment, the light irradiated by the light emitting unit (210) is irradiated in the positive direction of the x-axis along the first path (211).

At this time, the light irradiated by the light emitting unit (210) may be polarized, and there may be no limitation on the type of light.

Referring to FIG. 4, light irradiated along the first path (211) is irradiated from the light emitting portion (210) to the first reflecting portion (220') positioned in the positive direction of the x-axis.

At this time, the first reflector (220') may be positioned to be inclined at a first angle (θ1') with respect to the negative direction of the x-axis, and the first reflector (220') may be a half mirror that transmits a portion of the irradiated light and reflects the remaining portion, or a beam splitter that changes the travel path of a portion of the irradiated light.

More specifically, the first reflector (220') may be formed as a polarizing beam splitter or a dichroic beam splitter.

Accordingly, referring to FIGS. 2 and 4, some of the light reflected from the first reflector (220') among the light irradiated along the first path (211) can reach the wafer (400) along the second path (212') at an incident angle of the third angle (θ3').

At this time, light that reaches the wafer (400) with an incident angle of the third angle (θ3') must be reflected from the wafer (400) with a reflection angle of the third angle (θ3') and sequentially reach the camera (240) again along the second path (212') and the first path (211). Therefore, in the second embodiment of the present invention, the third angle (θ3') may be 90 degrees.

Meanwhile, the remaining light that is not reflected among the light irradiated along the first path (211) can be reflected from the second reflector (230') located in the positive direction of the x-axis from the first reflector (220') along the third path (213).

At this time, the second reflector (230') can be positioned to be inclined at a second angle (θ2') with respect to the positive direction of the x-axis.

Additionally, the second reflector (220') may be a mirror that reflects all of the light being irradiated.

At this time, the first reflector (220') and the second reflector (230') can be arranged so that the first angle (θ1') and the second angle (θ2') are equal.

Additionally, the first angle (θ1') and the second angle (θ2') can be 45 degrees.

Accordingly, referring to FIGS. 2 and 4, light irradiated along the third path (213) can be reflected by the second reflector (230') and reach the contact probe (110) along the fourth path (214') at an incident angle of the fourth angle (θ4').

At this time, the light that reaches the contact probe (110) with an incident angle of the fourth angle (θ4') must be reflected from the contact probe (110) with a reflection angle of the fourth angle (θ4') and sequentially reach the camera (240) again along the fourth path (214'), the third path (213), and the first path (211). Therefore, in the first embodiment of the present invention, the fourth angle (θ4') may be 90 degrees.

That is, referring to FIGS. 2 and 4, unlike the light reflected from the first reflection unit (220) of the optical device (200) for wafer alignment according to the first embodiment of the present invention reaches the lower portion of the contact probe (110) and the light reflected from the second reflection unit (230) reaches the upper portion of the wafer (400), the light reflected from the first reflection unit (220') of the optical device (200') for wafer alignment according to the second embodiment reaches the upper portion of the wafer (400) and the light reflected from the second reflection unit (230') reaches the lower portion of the contact probe (110).

Therefore, the optical device (200') for wafer alignment according to the second embodiment of the present invention can obtain an image of the upper part of the wafer (400) through light reflected from the first reflector (220'), and can obtain an image of the lower part of the contact probe (110) through light reflected from the second reflector (230').

In this way, the optical device (200') for wafer alignment according to the second embodiment of the present invention can simultaneously acquire images of the lower part of the contact probe (110) and the upper part of the wafer (400) using one camera (240) based on the same principle as described above.

For example, the light emitting unit (210) may irradiate unpolarized light, the first reflecting unit (220') may be a polarizing beam splitter, and the camera (240) may be a polarizing camera having both a P-wave receiving pixel and an S-wave receiving pixel.

At this time, the investigated light source is separated into P-wave polarization and S-wave polarization by the first reflector (220') and can reach the contact probe (110) and the wafer (400), respectively.

All of the light reflected from each of the contact probe (110) and the wafer (400) is received by the camera (240), and the camera (240) is a polarization camera that has both a P-wave receiving pixel and an S-wave receiving pixel, so that it is possible to acquire two images simultaneously.

In addition, the intensity of light irradiated to the contact probe (110) should generally be stronger than the intensity of light irradiated to the wafer (400). In this case, if the intensity of the light source irradiating the contact probe (110) and the wafer (400) should be different, the light emitting unit (210) can irradiate P-wave polarization and S-wave polarization at the same time with different intensities.

As another example, the light emitting unit (210) may emit white light, the first reflecting unit (220') may be a dichroic beam splitter, and the camera (240) may be a color camera.

At this time, the investigated light source is separated into two different color lights by the first reflector (210) and can reach the contact probe (110) and the wafer (400) respectively.

The light reflected from each of the contact probe (110) and the wafer (400) is received by the camera (240), and the camera (240) is a color camera with two different color pixels, so it is possible to acquire two images simultaneously.

In addition, the intensity of light irradiated to the contact probe (110) should generally be stronger than the intensity of light irradiated to the wafer (400). In this case, if the intensities of the light sources irradiating the contact probe (110) and the wafer (400) should be different, the light emitting unit (210) can irradiate two different color lights at different intensities simultaneously.

As another example, the light emitting unit (210) may alternately irradiate P-wave polarization and S-wave polarization, the first reflecting unit (220') may be a polarizing beam splitter, and the camera (240) may be a general black-and-white camera.

In general, the intensity of light irradiated to the contact probe (110) should be stronger than the intensity of light irradiated to the wafer (400). In this case, when the intensity of light sources irradiated to the contact probe (110) and the wafer (400) should be different, the light emitting unit (210) can selectively irradiate P-wave polarization and S-wave polarization to irradiate the intensities of the two light sources differently.

At this time, using a regular black and white camera can have the advantage of a wider range of choices compared to a polarizing camera.

Therefore, the prober (10) equipped with the optical device (200') for wafer alignment according to the second embodiment of the present invention can significantly reduce the movement distance of the chuck (500) required in the process of aligning the contact probe (110) and the wafer (400) compared to the prober (1000) according to the prior art, and thus can reduce the alignment error between the contact probe (110) and the wafer (400) caused by the movement of the chuck (500).

FIG. 5 is a configuration diagram of an optical device (200'') for wafer alignment according to a third embodiment of the present invention, and FIG. 6 is a configuration diagram of an optical device (200''') for wafer alignment according to a fourth embodiment of the present invention.

The third embodiment is a modified embodiment of the first embodiment. In the following, descriptions of the configurations of the third embodiment that are identical to those of the first embodiment will be omitted, and descriptions will be made mainly of configurations that are different from those of the first embodiment.

Referring to FIG. 5, an optical device (200'') for wafer alignment according to a third embodiment of the present invention may include a light emitting unit (210), a first reflecting unit (220''), a second reflecting unit (230''), a camera (240), and a camera movement module (250).

At this time, in the optical device (200'') for wafer alignment according to the third embodiment, the light emitting part irradiates light in the positive direction of the x-axis.

However, the light emitting unit (210) can irradiate light through two different paths (211a, 212b).

Referring to FIG. 5, the light emitting unit (210) irradiates light through two paths (211a, 211b), the 1a path (211a) and the 1b path (211b).

At this time, light irradiated along the 1a path (211a) can be irradiated upward at a fifth angle (θ5) from the positive direction of the x-axis.

Additionally, light irradiated along the 1a path (211a) can be irradiated from the light emitting portion (210) to the first reflecting portion (220'') positioned in the positive direction of the x-axis.

At this time, the first reflector (220'') can be positioned to be tilted upward at a first angle (θ1'') from the positive direction of the x-axis.

Additionally, the first reflector (220'') may be a mirror that reflects all of the light being irradiated.

Referring to FIG. 2 and FIG. 5, light irradiated along the 1a path (211a) can be reflected by the first reflector (220'') and reach the lower portion of the contact probe (110) along the 2-a path (212a) at an incident angle of a third angle (θ3'').

At this time, the light that reaches the bottom of the contact probe (110) with an incident angle of the third angle (θ3'') must be reflected from the bottom of the contact probe (110) with a reflection angle of the third angle (θ3'') and sequentially reach the camera (240) again along the 2-a path (212a) and the 1-a path (211a). Therefore, in the third embodiment of the present invention, the third angle (θ3'') may be 90 degrees.

Meanwhile, light irradiated along the 1b path (211b) can be irradiated downward at a sixth angle (θ6) from the positive direction of the x-axis.

At this time, the sixth angle (θ6) may or may not be equal to the fifth angle (θ5).

Additionally, light irradiated along the 1b path (211b) can be irradiated from the light emitting portion (210) to the positive direction of the x-axis and the second reflecting portion (230'') positioned below the first reflecting portion (220'').

At this time, the second reflector (230'') may be positioned to be tilted downward by a second angle (θ2'') from the positive direction of the x-axis, and the second angle (θ2'') may or may not be equal to the first angle (θ1'').

Additionally, the second reflector (230'') may be a mirror that reflects all of the light being irradiated.

Referring to FIG. 2 and FIG. 5, light irradiated along the 1b path (211b) can be reflected by the second reflector (230'') and reach the upper portion of the wafer (400) along the 2-b path (212b) at an incident angle of the fourth angle (θ4'').

At this time, the light that reaches the top of the wafer (400) with an incident angle of the fourth angle (θ4'') must be reflected from the top of the wafer (400) with a reflection angle of the fourth angle (θ4'') and sequentially reach the camera (240) again along the 2-b path (212b) and the 1-b path (211b). Therefore, in the third embodiment of the present invention, the fourth angle (θ4'') may be 90 degrees.

That is, referring to FIGS. 2 and 5, light reflected from the first reflector (220'') of the optical device (200'') for wafer alignment according to the third embodiment of the present invention reaches the contact probe (110), and light reflected from the second reflector (230'') reaches the wafer (400).

Accordingly, the optical device (200'') for wafer alignment according to the third embodiment of the present invention can obtain an image of the lower part of the contact probe (110) through light reflected from the first reflector (220''), and can obtain an image of the upper part of the wafer (400) through light reflected from the second reflector (230'').

In this way, the optical device (200'') for wafer alignment according to the third embodiment of the present invention can simultaneously acquire images of the lower part of the contact probe (110) and the upper part of the wafer (400) using one camera (240) based on the same principle as described above.

Therefore, the prober (10) equipped with the optical device (200'') for wafer alignment according to the third embodiment of the present invention can significantly reduce the movement distance of the chuck (500) required in the process of aligning the contact probe (110) and the wafer (400) compared to the prober (1000) according to the prior art, and thereby reduce the alignment error between the contact probe (110) and the wafer (400) caused by the movement of the chuck (500).

The fourth embodiment is a modified embodiment of the third embodiment. In the following, descriptions of the configurations of the fourth embodiment that are identical to those of the third embodiment will be omitted, and descriptions will be made mainly of configurations that are different from those of the third embodiment.

Referring to FIG. 6, an optical device (200''') for wafer alignment according to the fourth embodiment of the present invention may include a light emitting unit (210), a first reflecting unit (220'''), a second reflecting unit (230'''), a camera (240), and a camera movement module (250).

At this time, in the optical device (200''') for wafer alignment according to the fourth embodiment, the light emitting unit irradiates light in the positive direction of the x-axis along two different paths (211a', 212b').

At this time, light irradiated along the 1a path (211a') can be irradiated upward at a fifth angle (θ5') from the positive direction of the x-axis, and light irradiated along the 1b path (211b') can be irradiated downward at a sixth angle (θ6') from the positive direction of the x-axis.

At this time, the sixth angle (θ6') may or may not be equal to the fifth angle (θ5').

The light irradiated through the 1a path (211a') and the 1b path (211b') can reach the first reflector (220''') and the second reflector (230'''), respectively.

At this time, the first reflector (220''') may be arranged to be tilted upward at a first angle (θ1''') from the positive direction of the x-axis, and the second reflector (230''') may be arranged to be tilted downward at a second angle (θ2''') from the positive direction of the x-axis.

Additionally, the first angle (θ1''') and the second angle (θ2''') may be formed identically or not identically.

At this time, light irradiated along the 1a path (211a') can be reflected at the first reflector (220''') and reach the lower portion of the contact probe (110) along the 2-a path (212a') with an incident angle of the third angle (θ3''').

Referring to FIG. 6, light that reaches the bottom of the contact probe (110) with an incident angle of the third angle (θ3''') must be reflected from the bottom of the contact probe (110) with a reflection angle of the third angle (θ3''') and sequentially reach the camera (240) again along the 2-a path (212a') and the 1-a path (211a'). Therefore, in the third embodiment of the present invention, the third angle (θ3''') may be 90 degrees.

Additionally, light irradiated along the 1b path (211b') can be reflected at the second reflector (230''') and reach the upper portion of the wafer (400) along the 2-b path (212b') with an incident angle of the fourth angle (θ4''').

At this time, the light that reaches the top of the wafer (400) with an incident angle of the fourth angle (θ4''') must be reflected from the top of the wafer (400) with a reflection angle of the fourth angle (θ4''') and sequentially reach the camera (240) again along the 2-b path (212b') and the 1-b path (211b'). Therefore, in the third embodiment of the present invention, the fourth angle (θ4'') may be 90 degrees.

Meanwhile, referring to FIG. 6, the first reflector (220''') and the second reflector (230''') can be formed integrally.

At this time, the first reflector (220''') and the second reflector (230''') formed integrally may be positioned on one prism.

Therefore, the optical device (200''') for wafer alignment according to the fourth embodiment of the present invention is formed by integrally forming the first reflector (220''') and the second reflector (230'''), so that when moving the first reflector (220''') and the second reflector (230''') through the camera movement module (250), the positions thereof can be easily controlled.

In addition, referring to FIGS. 2 and 6, the optical device (200''') for wafer alignment according to the fourth embodiment of the present invention is similar to the optical device (200''') for wafer alignment according to the third embodiment. The light reflected from the first reflector (220''') of the optical device (200''') for wafer alignment according to the fourth embodiment of the present invention reaches the contact probe (110), and the light reflected from the second reflector (230''') reaches the wafer (400).

Accordingly, the optical device (200''') for wafer alignment according to the fourth embodiment of the present invention can obtain an image of the lower portion of the contact probe (110) through light reflected from the first reflector (220'''), and can obtain an image of the upper portion of the wafer (400) through light reflected from the second reflector (230''').

In this way, the optical device (200''') for wafer alignment according to the fourth embodiment of the present invention can simultaneously acquire images of the lower part of the contact probe (110) and the upper part of the wafer (400) using one camera (240) based on the same principle as described above.

Therefore, the prober (10) equipped with the optical device (200''') for wafer alignment according to the fourth embodiment of the present invention can significantly reduce the movement distance of the chuck (500) required in the process of aligning the contact probe (110) and the wafer (400) compared to the prober (1000) according to the prior art, and thereby reduce the alignment error between the contact probe (110) and the wafer (400) caused by the movement of the chuck (500).

According to a prober equipped with an optical device (200, 200', 200'', 200''') according to one embodiment of the present invention, unlike a conventional prober equipped with an optical device in which a chuck is moved to obtain an image of a contact probe and a wafer, an image of a contact probe and a wafer can be obtained by moving the optical device.

Therefore, according to a prober equipped with an optical device according to one embodiment of the present invention, the optical device moves instead of the chuck, so that errors in alignment between the contact probe and the wafer that occur when the chuck moves, such as thermal deformation of the wafer, can be reduced.

Although the embodiments of the present invention have been described, the spirit of the present invention is not limited to the embodiments presented in this specification, and those skilled in the art who understand the spirit of the present invention will be able to easily suggest other embodiments by adding, changing, deleting, or adding components within the scope of the same spirit, but this will also be considered to fall within the spirit of the present invention.

Claims (17)

As an optical device for wafer alignment for aligning a contact probe and a wafer facing the contact probe, A camera positioned between the contact probe and the wafer so as to face a first direction that is perpendicular to the direction in which the contact probe and the wafer face each other and is horizontal to the floor surface; A camera movement module for moving the camera so that the camera moves along the first direction; A light emitting unit coupled to the camera and emitting light between the contact probe and the wafer in the same direction as the direction in which the camera faces; A first reflector positioned at a front position of the camera and reflecting the light emitted from the light emitting unit so that the light can reach the contact probe; A second reflector positioned at a front position of the camera and configured to reflect the light emitted from the light emitting unit so that the light can reach the wafer; An optical device for wafer alignment, wherein the camera, the light emitting unit, the first reflector, and the second reflector are arranged such that a portion of the light irradiated from the light emitting unit is reflected by the first reflector and reaches the contact probe, the light reflected from the contact probe passes through the first reflector again and is imaged on the camera, the remaining portion of the light irradiated from the light emitting unit is reflected by the second reflector and reaches the wafer, and the light reflected from the wafer passes through the second reflector again and is imaged on the camera. In paragraph 1, The above first reflector is positioned so as to be inclined at a first angle with respect to the floor surface, The second reflector is positioned so as to be inclined at a second angle with respect to the floor surface, An optical device for wafer alignment, wherein the first angle and the second angle are the same, but the first reflector and the second reflector are not parallel. In the second paragraph, The above first reflector is a half mirror that transmits a portion of the irradiated light and reflects the remaining portion, or a beam splitter that changes the path of travel of a portion of the irradiated light. An optical device for wafer alignment, in which the light emitting portion, the first reflector, and the second reflector are arranged in a row so that light reaching the second reflector passes through the first reflector after being irradiated from the light emitting portion and reaches the second reflector. In the third paragraph, The above camera is a polarizing camera that has both P-wave photodetectors and S-wave photodetectors. The light irradiated by the above light emitting unit is unpolarized light, The above first reflector is an optical device for wafer alignment which is a polarizing beam splitter. In the third paragraph, The above camera is a color camera, The light irradiated by the above light emitting unit is white light, The above first reflector is an optical device for wafer alignment which is a dichroic beam splitter. In the third paragraph, The above camera is a polarizing camera that has both P-wave photodetectors and S-wave photodetectors. The light irradiated by the above light emitting unit is light that irradiates P-wave polarization and S-wave polarization simultaneously at different intensities. The above first reflector is an optical device for wafer alignment which is a polarizing beam splitter. In the third paragraph, The above camera is a color camera, The light irradiated by the above light emitting unit is light irradiated simultaneously with different intensities from two different colored light sources. The above first reflector is an optical device for wafer alignment which is a dichroic beam splitter. In the third paragraph, The above camera is a black and white camera, The light irradiated by the above light emitting unit is light irradiated by alternating P-wave polarization and S-wave polarization. The above first reflector is an optical device for wafer alignment which is a polarizing beam splitter. In the second paragraph, The above second reflector is a half mirror that transmits part of the irradiated light and reflects the remaining part, or a beam splitter that changes the path of travel of part of the irradiated light. An optical device for wafer alignment, in which the light emitting portion, the second reflector, and the first reflector are arranged in a row so that light reaching the first reflector passes through the second reflector after being irradiated from the light emitting portion and reaches the first reflector. In Article 9, The above camera is a polarizing camera that has both P-wave photodetectors and S-wave photodetectors. The light irradiated by the above light emitting unit is unpolarized light, The above first reflector is an optical device for wafer alignment which is a polarizing beam splitter. In Article 9, The above camera is a color camera, The light irradiated by the above light emitting unit is white light, The above first reflector is an optical device for wafer alignment which is a dichroic beam splitter. In Article 9, The above camera is a polarizing camera that has both P-wave photodetectors and S-wave photodetectors. The light irradiated by the above light emitting unit is light that irradiates P-wave polarization and S-wave polarization simultaneously at different intensities. The above first reflector is an optical device for wafer alignment which is a polarizing beam splitter. In Article 9, The above camera is a color camera, The light irradiated by the above light emitting unit is light irradiated simultaneously with different intensities from two different colored light sources. The above first reflector is an optical device for wafer alignment which is a dichroic beam splitter. In Article 9, The above camera is a black and white camera, The light irradiated by the above light emitting unit is light irradiated by alternating P-wave polarization and S-wave polarization. The above first reflector is an optical device for wafer alignment which is a polarizing beam splitter. In paragraph 1, The second reflector is located below the first reflector when viewed in the vertical direction, The above light emitting unit is an optical device for wafer alignment that irradiates light to each of the first reflecting unit and the second reflecting unit. In Article 15, An optical device for wafer alignment, wherein each of the first reflector and the second reflector is a mirror. In Article 15, The first reflector includes a first surface formed on a prism, An optical device for wafer alignment, wherein the second reflector is formed on the one prism and includes a second surface adjacent to the first surface.

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