KR20070073484A - Chemical Mechanical Polishing Method - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical mechanical polishing method. In the chemical mechanical polishing method for flattening the film quality formed on a wafer, the film quality is polished to a target value by using an in-line measurement method and an endpoint detection method. According to this, the inline measurement method and the endpoint detection method are used simultaneously, the inline measurement method automatically changes the conditions for each area, and the endpoint detection method performs the chemical mechanical polishing process according to the thickness target value, thereby improving the profile after polishing. You can get it.

Description

Chemical mechanical polishing method {CHEMICAL MECHANICAL POLISHING METHOD}

1 is a graph showing the profile form before and after polishing in general chemical mechanical polishing.

2 is a graph showing the change in the chemical mechanical polishing target value according to the consumable life in the chemical mechanical polishing according to the prior art.

3 is a flowchart illustrating a chemical mechanical polishing method according to an embodiment of the present invention.

Figure 4 is a plan view showing the head of the chemical mechanical polishing equipment in the chemical mechanical polishing method according to an embodiment of the present invention.

Figure 5 is a graph showing the targeting in the chemical mechanical polishing method according to an embodiment of the present invention.

6 and 7 are graphs showing the profile shape before and after polishing in the chemical mechanical polishing method according to an embodiment of the present invention.

The present invention relates to a chemical mechanical polishing method, and more particularly to a chemical mechanical polishing method that can improve the process dispersion.

As is well known, the chemical mechanical polishing process is a process for planarizing various various film qualities. In the chemical mechanical polishing process, as shown in FIG. 1, the profile after polishing tends to follow the profile shape as it is affected by the initial deposition thickness of the film. When the former profile is changed, the profile after the chemical mechanical polishing is affected in the changed form. In addition, as shown in FIG. 2, as the chemical mechanical polishing process proceeds, the chemical mechanical polishing target value changes according to the life of the consumable.

In order to overcome the above-mentioned problems, a heterogeneous recipe is used, in which only a specific area is polished. However, the conventional method exposes the problem that the grinding time should be adjusted manually by engineers and other workers by looking at the thickness data.

Accordingly, the present invention has been made to solve the above problems in the prior art, an object of the present invention to provide a chemical mechanical polishing method that can improve the profile after polishing.

The chemical mechanical polishing method according to the present invention for achieving the above object is characterized by improving the post-polishing profile by using in-line metrology and endpoint detection (EPD).

In the chemical mechanical polishing method according to an embodiment of the present invention capable of realizing the above characteristics, in the chemical mechanical polishing method for flattening the film quality formed on the wafer, the film quality is polished to the target value by using an in-line measurement method and an endpoint detection method. Characterized in that.

In this embodiment, after changing the polishing conditions for the film quality by the in-line measurement method, the film quality can be polished to the target value by the endpoint detection method.

In this embodiment, the film quality may be polished to the target value by the endpoint detection method, and the polishing conditions may be changed after measuring the thickness of the film quality by the in-line measurement method.

Chemical and mechanical polishing method according to an embodiment of the present invention that can implement the above features, in the chemical mechanical polishing method using a chemical mechanical polishing equipment having a plurality of platens, the platen of some of the plurality of platens In the step of changing the polishing conditions using the in-line measurement method, and the remaining platens of the plurality of platens, characterized in that it comprises the step of polishing to the target value under the changed polishing conditions using the endpoint detection method.

In the present embodiment, the step of changing the polishing conditions by using the in-line measuring method of the platens of the plurality of platens, using a head capable of applying a pressure separately for each area facing the platen Can be.

Chemical and mechanical polishing method according to another embodiment of the present invention that can implement the above features, in the chemical mechanical polishing method using a chemical mechanical polishing equipment having a plurality of platens, the platen of some of the plurality of platens And polishing the target value using an endpoint detection method, and changing the conditions of polishing using the endpoint detection method using an inline measurement method on the remaining platens of the plurality of platens. It features.

In another embodiment of the present invention, the changing of the polishing conditions using the endpoint detection method using the in-line measurement method in the remaining platens of the plurality of platens may be performed by dividing the respective areas in opposition to the platens. A head capable of applying pressure can be used.

According to the present invention, the in-line measurement method and the endpoint detection method are used simultaneously, the in-line measurement method automatically changes the conditions for each area, and the endpoint detection method improves the post-polishing profile by performing the chemical mechanical polishing process according to the thickness target value. .

Hereinafter, a chemical mechanical polishing method according to the present invention will be described in detail with reference to the accompanying drawings.

Advantages over the present invention and prior art will become apparent through the description and claims with reference to the accompanying drawings. In particular, a device for manufacturing a semiconductor device according to the present invention is well pointed out and claimed in the claims. However, the apparatus for manufacturing a semiconductor device according to the present invention can be best understood by referring to the following detailed description with reference to the accompanying drawings.

(Example)

3 is a flowchart illustrating a chemical mechanical polishing method according to an embodiment of the present invention.

Referring to FIG. 3, in the chemical mechanical polishing method of the present embodiment, a wafer is loaded (S100) in a chemical mechanical polishing facility, for example, a Reflexion model available from AMAT. Here, the chemical mechanical polishing process is performed for each platen 100, 200, 300 in a time control manner. Chemical mechanical polishing (CMP) is used in processes that require planarization of film quality such as inter layer dielectric (ILD), inter metal dielectric (IMD), shallow trench isolation (STI) during wafer processing.

In the chemical mechanical polishing of the present embodiment, in-line metrology is applied to the first platen 100 and the second platen 200 (S200), and the endpoint detection method is applied to the third platen 300. Applying (EPD) (S300) allows targeting.

Polishing using the in-line measuring method predicts the process time by using the relationship between thickness before and after polishing and time. For example, the thickness of the film to be polished is measured and thereby the polishing process is performed for a set time. The thickness is then measured by in-line metrology and the polishing time is automatically corrected by the measured thicknesses. The thickness is measured for the film quality remaining after polishing during the calibrated process time. The process time can be corrected based on the measured thickness data. In the case of the Reflexion model available from AMAT Co., Ltd., the first and second platens 100 and 200 apply WIW APC (Within Wafer Advanced Process Cotrol) using a measuring instrument.

An endpoint detection method (EPD) is to monitor the polishing state during wafer processing to detect the endpoint of polishing to be targeted. Endpoint detection methods include motor current method and optical method. The motor current method detects the endpoint by changing the current of the driving motor when dissimilar materials are exposed. The optical method is a method of directly measuring the thickness using reflection of a thin film, a method of detecting a difference in reflectance of a thin film when a heterogeneous thin film is exposed, and a method of determining a point where the double interference disappears by detecting the occurrence of double interference by a pattern Etc.

During the initial polishing process set-up, the polishing conditions are set to be closest to the target value (target) in consideration of the entire profile.The polishing conditions are initially set by the life of consumables (eg, polishing pad) or the change of the entire profile. When the polishing is continued, the dispersion becomes bad. In order to improve this, the present embodiment uses an inline measurement method and an endpoint detection method together.

Specifically, once the wafer is loaded (S100), the chemical mechanical polishing is performed on the first and second platens 100 and 200. At this time, the pre-polishing profile and the post-polishing profile are applied to each region of the head of the chemical mechanical polishing facility by in-line metrology. It automatically adjusts by receiving data and feedback. In other words, the difference between the target and the target from the measured data is automatically adjusted. On the other hand, as shown in Figure 4, the head 90 of the chemical mechanical polishing equipment should be divided into each area, it would be desirable to be able to give pressure separately for each area.

Referring back to FIG. 3, the conditions for each area of the head 90 are automatically changed by in-line metrology, and then the target of the film thickness is adjusted using an endpoint detection method (EPD). give. As in the previous example, as shown in FIG. 5, in the case of the Reflexion model available from AMAT Co., Ltd., the WIW APC (Within Wafer Advanced Process Cotrol) using a measuring instrument is applied to the first and second platens 100 and 200. The third platen 300 is targeted by applying an endpoint detection method (EPD).

For example, as shown in FIG. 6, the chemical mechanical polishing (CMP) showed about 2000 microseconds of scattering. As shown in FIG. 7, the chemical mechanical polishing using WIW APC and EPD resulted in about 1000 microseconds of scattering. It can be seen that improved.

Until now, the use of the WIW APC and targeting using the EPD has been described. Alternatively, the WIW APC may also be performed after the EPD is first performed. In addition, there is no limitation of the slurry in actual chemical mechanical polishing (CMP).

The foregoing detailed description illustrates the present invention. In addition, the foregoing description merely shows and describes preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications, and environments. And, it is possible to change or modify within the scope of the concept of the invention disclosed in this specification, the scope equivalent to the written description, and / or the skill or knowledge in the art. The above-described embodiments are for explaining the best state in carrying out the present invention, the use of other inventions such as the present invention in other state known in the art, and the specific fields of application and uses of the present invention. Various changes are also possible. Accordingly, the detailed description of the invention is not intended to limit the invention to the disclosed embodiments. Also, the appended claims should be construed to include other embodiments.

As described in detail above, according to the present invention, by using the inline measurement method and the endpoint detection method at the same time, the conditions for each area are automatically changed by the inline measurement method, and the chemical mechanical polishing process is performed according to the endpoint detection method to the thickness target value. Done. This has the effect of improving the profile after polishing.

Claims (7)

In the chemical mechanical polishing method for planarizing the film quality formed on the wafer, And chemically polishing the film to a target value by using an in-line measurement method and an endpoint detection method. The method of claim 1, And changing the polishing conditions for the film quality by the inline measuring method, and then polishing the film quality to a target value by the endpoint detection method. The method of claim 1, And polishing the film quality to a target value by the endpoint detection method, and measuring the thickness of the film quality by the in-line measurement method and changing the polishing conditions. In the chemical mechanical polishing method using a chemical mechanical polishing equipment having a plurality of platens, Changing the polishing conditions using in-line metrology in some of the platens, and polishing the target values in the changed polishing conditions using the end point detection method in the remaining platens of the plurality of platens. Chemical mechanical polishing method comprising the step of. The method of claim 4, wherein In some of the platens of the plurality of platens, the step of changing the polishing conditions using in-line metrology may be performed by using a head capable of applying pressure separately for each region against the platen. Polishing method. In the chemical mechanical polishing method using a chemical mechanical polishing equipment having a plurality of platens, Polishing of the platens of the plurality of platens to a target value using an endpoint detection method; and polishing conditions using the endpoint detection method of the other platens of the plurality of platens using an inline measurement method. Chemical mechanical polishing method comprising the step of changing the. The method of claim 6, The changing of the polishing conditions using the endpoint detection method using the in-line measurement method in the remaining platens of the plurality of platens, using a head that can apply pressure separately for each area facing the platen Chemical mechanical polishing method characterized in that.

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