JP3225780B2 - Device for measuring the amount of deposits on the sample surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to quickly measure fine particles (particles) adhering to the surface of a sample such as a semiconductor manufacturing wafer or a component of a manufacturing apparatus thereof in a dry state without contact. It relates to a measuring device.

[0002]

2. Description of the Related Art Conventionally, methods for measuring the amount of deposits adhered to the surface of a sample include a method of irradiating a sample immersed in pure water or the like with ultrasonic waves to measure the amount of the deposits separated from the surface. There is a method in which a heavy object is dropped on a sample, and the amount of the adhering matter separated from the surface of the sample by the impact is measured.

[0003]

In the former method using ultrasonic waves, not only the deposits but also the surface of the sample are peeled off due to the cavitation phenomenon caused by the ultrasonic waves, and the sample may be damaged. In addition, since ultrasonic irradiation is performed in a liquid such as pure water, measurement cannot be performed in a dry state, and when this method is used for evaluation of cleanliness after washing, the sample may be dried or washed again after measurement. is necessary. In the method of dropping a heavy object, since the heavy object is applied to the back surface of the sample, measurement cannot be performed without contact, and the back surface of the sample or the sample itself may be damaged. Further, since the heavy object comes into contact with the sample, the cleanliness of the sample may be deteriorated.

[0004]

SUMMARY OF THE INVENTION The present invention has been developed to solve the above-mentioned problems of the conventional method and to measure the amount of deposits on the surface of a sample in a non-contact and dry state. The apparatus for measuring the amount of deposits on the surface of a sample according to claim 1 is cylindrical.
A chamber, a sound wave generating means provided on the tubular chamber, a support portion of the sample provided in the cylindrical chamber while maintaining the sound wave generator and the gap,
A particle measuring unit configured to introduce an air current containing particles separated from the sample by a sound wave. Further, the measuring device for measuring the amount of deposits on the sample surface according to claim 2 is:
The distance between the cylindrical chamber and the sample provided in the cylindrical chamber can be changed
Sound wave generating means, and a cylindrical chamber with a gap between the sound wave generating means
The sample support provided on the upper surface of the sample by sound waves
Particles adapted to introduce airflow containing particles separated from
4. The sample table according to claim 3, further comprising a measuring unit.
A measuring device for the amount of deposits on the surface is provided in the cylindrical chamber and the cylindrical chamber.
Sound wave generation means that can change the distance to the sample
A sample support provided in a cylindrical chamber while keeping a gap with the means
Gas containing particles separated from the lower surface of the sample by sound waves
A funnel-shaped chamber for introducing a flow into the particle measuring means;
Particle measuring means connected to the chamber and introducing an air flow containing particles,
It is characterized by having.

[0005]

FIG. 1 shows a first embodiment of a measuring apparatus according to the present invention, and FIG.
3 is a cross-sectional view showing a second embodiment, and FIG. 3 is a cross-sectional view showing another embodiment. In FIG.
Sound wave generating means comprising an amplifier 12 and a speaker 13; 21
Denotes a supply of clean air for generating an air flow containing particles separated from the surface of the sample, for example, a blower with an air filter, and 23 denotes a particle measuring means, for example, a particle counter of a light scattering type or a light blocking type. The sound wave signal generator 11 of the sound wave generation means can output an arbitrary frequency signal. For example, from 30 to 20,000 Hz, a frequency at which the generated sound wave and the sample (eg, a wafer) resonate to obtain the largest vibration can be obtained. Use what you can choose. When the air from the supply unit 21 of the clean air containing the separated particles flows in at a predetermined flow rate, for example, 30 cubic minutes, the particle counter of the particle measuring means 23 changes the particle diameter, for example, every 0.3 to 5 μm. Count and display the number of particles present in the air.

In each of the illustrated embodiments, a speaker 13 is provided under a top cover 14 in a cylindrical chamber 15 which is open up and down.
The position is provided so that it can be adjusted up and down. For this reason, the upper lid 14 and the cylindrical chamber 15 are interposed with a partition plate 16 interposed therebetween, and are assembled so as to be separable by flange joining. It penetrates from below and engages with a pinion 19 provided on the partition, so that the shaft of this pinion can be rotated via a worm gear mechanism (not shown) also provided on the partition. Accordingly, the upper lid 14 is removed from the partition plate, and the pinion 19 is rotated in the normal and reverse directions through the worm gear mechanism to move the speaker 13 together with the mounting plate 17 up and down in the cylindrical chamber, according to the size and thickness of the sample. The speaker can be adjusted to a desired height. The speaker and the mounting plate turn the pinion 19 by its weight and try to descend from the adjusted position, but the pinion cannot rotate because the worm gear mechanism is connected to the shaft of the pinion.
The speaker rests in the adjusted position.

[0007] The signal generator 11 and the amplifier 12 are connected outside the upper cover, and the cable extending from the amplifier enters the upper cover 14, reaches the speaker 13 along the rack 18, and is connected to the speaker.

Preferably, the upper lid and the cylindrical chamber are made of stainless steel, which is easy to clean, and a flexible and elastic seal 20 made of silicon rubber or the like is provided on the lower peripheral edge of the cylindrical chamber 15.

In the embodiment shown in FIG. 1, the sample 1 is placed on the table 31 with the fine particle adhering surface 2 facing upward and facing the speaker. The sample is a plate such as a wafer, and the diameter thereof is
If it is slightly larger, the cylindrical chamber is placed on the sample 1 such that the lower peripheral edge of the cylindrical chamber rests on the peripheral edge of the sample. When the sample is smaller than the diameter of the cylindrical chamber, the cylindrical chamber is placed directly on the table such that the lower peripheral edge of the cylindrical chamber rests on the stainless steel or aluminum table upper surface 3 around the sample. .

An air supply pipe 22 from a clean air supply 21 and a particle measuring means 23 are connected to the cylindrical chamber. The height of the speaker is appropriately determined with respect to the sample, and the generation frequency of the sound wave signal generator of the sound wave generator 10 is optimally determined according to the sample,
When a sound wave is applied to the sample while supplying clean air from the supply device 21 into the cylindrical chamber, the vibration caused by the sound wave and the density difference of the clean air in the cylindrical chamber at that time (when the sound wave hits the surface of the sample) (A phenomenon similar to a vacuum state caused by a difference between a dense state and a sparse state at the time of reflection)), the adhered substance is separated from the adhered surface 2 of the sample 1, and particles are generated by an air flow from a supply unit 21 of clean air. The particles are sent to the measuring means 23 and counted for each particle size.

As described above, in the embodiment shown in FIG. 1, even if the sample has a diameter smaller than the diameter of the cylindrical chamber or the sample has a diameter slightly larger than the diameter of the cylindrical chamber, the adhering substances adhered to the surface of the sample are peeled off.
It can be counted and measured. Also, a seal 20 at the lower end of the cylindrical chamber is provided.
Is in close contact with the peripheral portion of the sample 1 and the upper surface of the table, and prevents the outside air from entering the cylindrical chamber and prevents the particles of the detached deposits from coming out of the cylindrical chamber, so that accurate measurement can be performed. At the same time, it comes into soft contact with the sample and does not damage the periphery of the sample.

In the embodiment shown in FIG. 2, the cylindrical chamber 15 is supported on an upright funnel-shaped chamber 33 supported by an auxiliary table 32 and having an upper peripheral edge having the same diameter as the lower peripheral edge of the cylindrical chamber 15.
A flexible and resilient seal 34 made of silicon rubber or the like is also provided on the peripheral edge of the upper end of the funnel-shaped chamber 33. The air supply pipe 22 of the clean air supply device is connected to the funnel-shaped chamber 33, and the particle measuring means 23 is connected to the small diameter lower end of the funnel-shaped chamber.

In the second embodiment, a cylindrical chamber 15 having the same diameter is used.
Of the plate-like sample 1, for example, a wafer having a slightly larger diameter, is sandwiched between the lower peripheral edge of the lower end and the upper peripheral edge of the funnel-shaped chamber 33 with the fine particle adhering surface 2 facing downward. Install with. The cylindrical chamber 15 is in contact with the peripheral portion of the sample from above with the seal 20, and the funnel-shaped chamber 33 is in contact with the peripheral portion of the sample from below with the seal 34, so that outside air may enter the cylindrical chamber and the funnel chamber. In addition, since the separated particles are prevented from flowing out, accurate measurement can be performed, and the upper and lower surfaces of the peripheral portion of the sample are not damaged.

The height of the loudspeaker is appropriately determined with respect to the sample, the frequency of the sound wave generator of the sound wave generator is determined optimally according to the sample, and the clean air is supplied from the supply device 21 to the funnel-shaped chamber 33. When a sound wave is applied to the upper surface of the sample from the speaker 13, the sample vibrates, and the adhered material is separated from the adhered surface 2 of the sample by the vibration, and flows to the particle measuring means 23 by a stream of clean air supplied to the funnel-shaped chamber. And counted for each particle size.

In the embodiment shown in FIG. 2, unlike the embodiment shown in FIG. 1, since there is nothing other than the sample in the funnel-shaped chamber, the amount of deposits is measured with higher accuracy than the embodiment shown in FIG. be able to.

In the embodiment shown in FIG. 3, the measurement is performed in such a manner that the fine particle adhering surface 2 of the sample is directed upward and facing the speaker 13 as in FIG. 1, and the fine particle adhering surface 2 of the sample is directed downward as in FIG. It is a device that can perform both measurements performed for For this reason,
The particle measuring means 23 is connected to the cylindrical chamber 15 and the lower end of the funnel-shaped chamber 33, respectively. Then, the air supply pipe 22 of the clean air supply device is branched into two branches and connected to the two chambers 15 and 33, so that the clean air can be supplied to one of the chambers by the switching cock or the valve 35.

Therefore, the diameter of the cylindrical chamber 15 such as a wafer
Alternatively, in the case of a sample slightly larger than the funnel-shaped chamber 33, the sample 1 is supported by sandwiching the peripheral edge between the opposite ends of the two chambers 15, 33, and supporting the sample 1 with the fine particle-adhering surface 2 facing upward. The clean air is supplied into the room, and the fine particles separated from the sample can be measured by the particle measuring means connected to the cylindrical chamber due to the vibration caused by the sound wave from the speaker and the density difference of the indoor air. Conversely, the sample was similarly supported with the fine particle-adhering surface 2 facing downward, and the adhered material was peeled off in the funnel-shaped chamber by sound waves from the speaker, and connected to the chamber with clean air supplied to the chamber. It can also be sent to a particle measuring means and measured.

In the case of a sample having a smaller diameter than the cylindrical chamber or the funnel-shaped chamber, the sample mounting plate 4 made of stainless steel or aluminum whose diameter is slightly larger than that of the cylindrical chamber 15 or the funnel-shaped chamber. The sample 1 is placed with the fine particle adhering surface 2 facing upward, and the peripheral edge of the mounting plate is sandwiched between the opposed ends of the cylindrical chamber 15 and the funnel-shaped chamber 33 to supply clean air into the cylindrical chamber. Then, the fine particles are separated from the sample by the vibration caused by the sound wave from the speaker and the density difference of the air in the room, and the particles are measured by the particle measuring means connected to the cylindrical chamber.

Seal 20 for cylindrical chamber, seal 3 for funnel chamber
No. 4 does not damage the sample or the sample mounting plate, and can perform accurate measurement to prevent invasion of outside air into the room and outflow of separated particles to the outside of the room.

[0020]

As is clear from the above, according to the present invention, the adhered substance that adheres to the surface of the sample without damage is peeled off by a sound wave without damaging the specimen, and the peeled-off substance is removed by air current.
It can be introduced into the particle measuring means to measure the amount. Further, since the peeling and measurement are performed in a dry state, it can be used for evaluation of cleanliness after washing. And the device of claim 2
According to the configuration, even if the sample is smaller than the diameter of the cylindrical chamber,
Even samples with a diameter slightly larger than the diameter of the chamber
The attached matter is peeled off, and the measurement can be performed by counting. In addition,
In the apparatus according to claim 3, clean air is supplied from the supply device to the funnel-shaped chamber.
Sonication from the speaker on the sample
The material attached to the material is peeled off, and the material
The particle measuring means with a stream of clean air supplied to the funnel-shaped chamber
And can be counted for each particle size. And the funnel
Since there is nothing other than the sample in the chamber,
The amount of kimono can be measured.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment of a measuring apparatus according to the present invention.

FIG. 2 is a sectional view of a second embodiment of the measuring device of the present invention.

FIG. 3 is a sectional view of a third embodiment of the measuring device of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sample (wafer) 2 sample adhering surface 3 sample upper surface 4 sample mounting plate 10 sound wave generator 11 sound wave signal generator 12 amplifier 13 speaker 14 upper lid 15 cylindrical chamber 16 partition 17 speaker mounting plate 18 rack 19 Pinion 20 Seal 21 Clean air supply 22 Air supply pipe 23 Particle measuring means 31 Table 32 Auxiliary table 33 Funnel-shaped chamber 34 Seal 35 Cock

Claims (3)

(57) [Claims] A cylindrical chamber ; a sound wave generating means provided in the cylindrical chamber; a sample support provided in the cylindrical chamber while keeping a gap from the sound wave generating means; and a particle separated from the sample by the sound wave. A particle measuring means adapted to introduce an air flow containing the particles. 2. A sound generator capable of changing the distance between a cylindrical chamber and a sample provided in the cylindrical chamber.
A sample provided in a cylindrical chamber with a gap between the step and the sound wave generating means
A support portion, an air flow containing the exfoliated particles from the upper surface of the sample by wave
Characterized by having a particle measuring means adapted to be introduced
A device for measuring the amount of deposits on the sample surface. 3. A sound generator capable of changing the distance between a cylindrical chamber and a sample provided in the cylindrical chamber.
A sample provided in a cylindrical chamber with a gap between the step and the sound wave generating means
A support portion, an air flow containing the exfoliated particles from the lower surface of the sample by wave
A funnel-shaped chamber to be introduced into the particle measuring means, and a particle meter connected to the funnel-shaped chamber and introducing an air flow containing particles
Measuring means for measuring the amount of deposits on the surface of the sample, comprising:
Place.