KR20090060733A - Cleansing method for maintenance of lower electrode in etching chamber - Google Patents

Abstract

A cleaning method for managing a bottom electrode inside an etching chamber is provided to shorten a time required for managing a bottom electrode by using a chemical material of liquid state in order to remove foreign material of a surface of the bottom electrode in which embossing is formed. A take-in test step(51) measures a dimension of a fixed part of a bottom electrode separated from an etching chamber. A preprocess step(52) cleans a surface of the bottom electrode by using mixture solution of KOH, H2O2, and deionized water for 10~60 minutes. A cleaning step(53) cleans the surface of the bottom electrode by using mixture solution of HF, HNO3, and deionized water for 10~60 minutes. A neutralization process step(54) cleans the surface of the bottom electrode by using the deionized water for 30~60 minutes after cleaning the surface of the bottom electrode by using mixture solution of acid diluents and deionized water for 10~60 minutes. A post process step(55) cleans the surface of the bottom electrode by using alcohol for 30~60 minutes. A baking step(56) leaves the surface of the bottom electrode at a fan flow atmosphere of 20~60 degrees for 3~10 hours after blowing the surface of the bottom electrode at a room temperature for 10~30 minutes. A take-out test step(57) compares a dimension of the surface of the baked bottom electrode with the dimension measured in the take-in test step.

Description

Cleaning Method for Regeneration of Lower Electrode in Etch Chamber of Semiconductor Equipment

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a method of regenerating a lower electrode in an etch chamber of a semiconductor device, and more particularly, by using a liquid chemical to remove foreign substances on the surface of a lower electrode having a surface on which embossing is formed. The present invention relates to a cleaning method for regenerating a lower electrode in an etching chamber of a new semiconductor device, which can effectively remove only foreign substances while reducing the original surface of the electrode, shorten the time required for lower electrode regeneration, and reduce the cost of regeneration.

For example, in order to manufacture a semiconductor device such as a liquid crystal display (LCD), oxidation, masking, photoresist coating, etching, diffusion, and lamination of an object to be processed, and cleaning, drying, and inspection performed before and after these processes are performed. Several processes have to be carried out, and the corresponding special equipment is used for each process. In the dual etching process, a process of partially removing a target layer to obtain a desired pattern is performed. The etching process includes wet etching using chemicals and dry etching of gaseous etching gas such as plasma etching, ion beam etching, and reactive ion etching. .

In general, the etching process introduces an etching gas into the etching chamber 10 as shown in FIG. 1 and is accelerated by the voltage applied to the upper electrode 14 and the lower electrode 16 to be processed onto the workpiece 12. The surface of the workpiece 12 is etched by being guided to and reacted with the film on the surface of the workpiece 12. The lower electrode 16 in the conventional etching chamber 10 is, for example, disclosed in the publication of the Korean Utility Model Registration No. 20-0359870 (Registration Date August 12, 2004) “Lower electrode for semiconductor and liquid crystal panel manufacturing equipment”. Likewise, in order for the etching gas to be uniformly supplied to the object 12 to be uniformly etched, the etching gas has a shape having countless protrusions or embossing 20 on the surface thereof (see FIG. 2).

The etching chamber 10 is periodically dismantled for maintenance to repair. In the lower electrode 16, foreign substances, such as molybdenum (Mo), that are separated from the O-ring in the chamber or the etching solution are sandwiched between the embossing 20 structures, thereby removing these foreign substances and regenerating the original embossing structure. This is necessary. As shown in FIG. 3, the regeneration operation of the lower electrode 16 has conventionally used a spray gun method. In general, the lower electrode 16 is an anodized (anodically oxidized) surface of an aluminum base material, and an aluminum oxide film 22 is coated on the surface thereof, and a product having embossed using a ceramic coating is widely used. Conventionally, the foreign material 30 is removed and reused by spraying aluminum oxide particles onto the spray gun 40 from the upper portion of the lower electrode 16.

By the way, in the regeneration method of such a spray gun method, the regeneration operation is very long, about two weeks, and after the aluminum oxide particles are sprayed with the spray gun, the embossed structure is damaged. There were disadvantages such as risk. Accordingly, there is a problem in that a preliminary lower electrode needs to be prepared and the cost of the regeneration work is excessively high. Therefore, there is an urgent need for a new technology that can shorten the time required for the regeneration operation without changing the embossing structure during the regeneration of the lower electrode.

The present invention is designed to improve the problem of the regeneration method of the lower electrode in the etching chamber of the conventional semiconductor equipment described above, by using a liquid chemical to remove foreign substances on the surface of the lower electrode having a surface on which embossing is formed In addition, the present invention provides a cleaning method for regenerating the lower electrode in the etching chamber of the new semiconductor equipment, which can effectively remove only foreign substances while maintaining the original surface of the lower electrode, shorten the time required for the lower electrode regeneration, and reduce the cost of regeneration work. For that purpose.

This object is achieved by a cleaning method for regeneration of a lower electrode in an etch chamber of a semiconductor device provided in accordance with the present invention.

A cleaning method for regenerating a lower electrode in an etch chamber of a semiconductor device according to an embodiment of the present invention includes: a wearing test step of measuring a dimension of a predetermined portion of a lower electrode separated from the etch chamber; The surface of the lower electrode that was received and inspected was prepared by mixing potassium hydroxide (KOH): hydrogen peroxide (H2O2): deionized water (DIW) in 7 to 13 parts by weight: 7 to 13 parts by weight: 42 to 78 parts by weight. A pretreatment step of washing for 60 minutes and then for 30 to 60 minutes with purified water; The surface of the pretreated lower electrode was washed with 10 to 60 minutes with a solution of hydrofluoric acid (HF): nitric acid (HNO3): purified water 7 to 13 parts by weight: 7 to 13 parts by weight: 210 to 390 parts by weight, and then purified water. A washing step of washing for 30 to 60 minutes; A neutralization step of washing the surface of the cleaned lower electrode with an acid neutralizer: 7 to 13 parts by weight of purified water: 7 to 13 parts by weight with a solution mixed for 10 to 60 minutes and then washing with purified water for 30 to 60 minutes; A post treatment step of washing the surface of the neutralized lower electrode with alcohol for 30 to 60 minutes; Baking the surface of the post-treated lower electrode at room temperature for 10 to 30 minutes, and then leaving it for 3 to 10 hours in a fan flow environment at 20 to 60 degrees; And a factory inspection step of re-measuring the dimensions of the portion measured in the receipt inspection step with respect to the surface of the baked lower electrode.

In a preferred embodiment, the inspection in the goods receipt and shipment inspection step is the height of the selected embossed portion of the lower electrode, the surface roughness of the selected portion, the edge portion of the lower electrode without embossing, that is, the roughness of the dam, embossing and dam It includes a damaged part of.

According to the present invention, by using a liquid chemical to remove foreign substances on the surface of the lower electrode having an embossed surface, only the foreign substances are effectively removed while maintaining the original surface of the lower electrode and required for regeneration of the lower electrode. The time period can be drastically shortened from 2 weeks to 3 to 4 days, and there is no need to prepare a spare lower electrode, and the cost of regeneration can be reduced by about 50% or more, thereby reducing the operating cost of the etching chamber. There is.

Hereinafter, a cleaning method for regenerating a lower electrode in an etch chamber of a semiconductor device according to the present invention will be described with reference to the accompanying drawings.

4 is a schematic diagram illustrating a cleaning method for regeneration of an etch chamber lower electrode according to an embodiment of the present invention, and FIG. 5 is a view illustrating a cleaning method for regeneration of an etch chamber lower electrode according to an embodiment of the present invention. This is a flowchart for explaining the process.

In the present invention, the chemical solution 100 acts on the surface of the lower electrode 16 in FIG. 4, and has the steps as shown in FIG. 5 as a flowchart. ) Is a cleaning method (50) for regeneration. Although the method of the present invention is based on a product used as an electrostatic control (ESC) electrode as the TEL lower electrode as an example of the lower electrode, it will be readily understood by those skilled in the art that any lower electrode having a similar embossing structure can be applied.

The method 50 undergoes three chemical treatment steps after the receipt inspection step 51, that is, the pretreatment step 52, the cleaning step 53, and the neutralization step 54, and then for washing the drug residues. After the post-treatment step 55, the baking step 56 is dried at a relatively low temperature. After completing all steps, the lower electrode 16 is inspected at the factory inspection step 57.

The receipt test step 51 is a step of measuring a dimension of a predetermined portion of the lower electrode 16 separated from the etching chamber. In a preferred embodiment, the inspection in the goods receipt inspection step 51 is carried out, for example, the height of the selected embossed portion at, for example, 16 points of the plurality of embosses constituting the embossing 20 structure of the lower electrode 16, for example 16. It is possible to measure the surface roughness of the selected part of the three points, the edge part of the lower electrode 16 without embossing, that is, the roughness of eight points of the dam, for example, the position and condition of the damaged part of the embossing and the dam, respectively. This measurement data can then be compared with the data examined in the factory inspection step 157.

The pretreatment step 52 is a step of preliminarily chemically treating the surface of the lower electrode 16 that is received and inspected, and contains 7 to 13 weights of potassium hydroxide (KOH): hydrogen peroxide (H 2 O 2): deionized water (DIW). Parts: 7 to 13 parts by weight: a solution mixed at 42 to 78 parts by weight, or preferably a solution mixed at a ratio of 10:10:60 by weight, for example, by wiping in a wiper for 10 to 60 minutes, preferably 30 minutes After washing for 30 minutes or more, preferably 30 minutes to 60 minutes with purified water. If the amount of potassium hydroxide (KOH) and hydrogen peroxide (H2O2) is excessive or the cleaning time is longer, the surface of the lower electrode may be unnecessarily stressed, which may cause damage to the emboss structure, and conversely, potassium hydroxide (KOH) ) And when the amount of hydrogen peroxide (H 2 O 2) is insufficient or the cleaning time is shorter there is a disadvantage that the efficiency of the subsequent chemical treatment is reduced.

The cleaning step 53 is a step of removing foreign matter with a strong acid solution. The surface of the pretreated lower electrode 16 is hydrofluoric acid (HF): nitric acid (HNO 3): purified water 7 to 13 parts by weight: 7 to 13 parts by weight. Part: A solution mixed at 210 to 390 parts by weight, preferably a solution mixed at a weight ratio of 10: 10: 300, for example by wiping in a wiper for 30 minutes or more, preferably 30 minutes to 60 minutes, and then 10 minutes 30 with purified water Wash for more minutes. If necessary, if there is a structure such as a fine hole, this fine structure can be further washed with purified water. If the amount of hydrofluoric acid (HF) or nitric acid (HNO3) is excessive or the cleaning time is longer, the risk of damaging not only the foreign matter on the lower substrate but also the embossed structure increases, and conversely, the hydrofluoric acid (HF) or nitric acid (HNO3) is increased. If the amount of) is insufficient or the cleaning time is shorter, there is a high risk that foreign substances on the lower substrate may not be removed to a desired degree.

The neutralization step 54 is a step of neutralizing the surface treated with the strong acid in the washing step, wherein the surface of the cleaned lower electrode 16 is acid neutralizing agent: 7 to 13 parts by weight: 7 to 13 parts by weight It is a step of washing for 10 to 60 minutes with a mixed solution, preferably a solution mixed in a 1: 1 weight ratio, and then washed with purified water for 30 minutes or more, preferably 30 minutes to 60 minutes. In general, the acid neutralizing agent may be used as long as it is an alkaline component that neutralizes acid. In the neutralization step 54, if the amount of acid neutralizer is excessive or the cleaning time is longer, the surface of the lower electrode is inclined too much to be alkaline, which may cause incomplete finishing of the surface treatment of the lower substrate. When the amount of topical agent is insufficient or the cleaning time is shorter, the surface of the lower electrode is not completely neutralized and acidity is still present, so that after finishing the surface treatment of the lower substrate, the surface finish of the lower substrate is incomplete. Side effects can occur.

The post-treatment step 55 is a step of cleanly cleaning the chemically treated surface in the preceding steps, after spraying the surface of the neutralized lower electrode 16 with, for example, an alcohol such as isopropyl alcohol (IPA) with a spray gun, for example. Washing for at least 30 minutes, preferably 30 to 60 minutes, for example using a wiper. This step is to ensure the complete removal of any acidic or alkaline chemical components that may have been left behind in the preceding steps, which may be incomplete if the cleaning time is too short and the cleaning time is longer. There is a fear that the work time will be unnecessarily long.

The baking step 56 is a step of drying the cleaned surface, and blows the surface of the post-treated lower electrode 16 with air at room temperature for 10 to 30 minutes, preferably 20 minutes, and then fan flow at 40 degrees. It is a step of drying for 3 to 10 hours in a flow environment. This step is a step of drying the lower substrate in a relatively low temperature environment. If the temperature is higher or longer, there is a risk of excessive work time or cost, and at a lower temperature or shorter time. There is a fear that the desired degree of drying is not achieved.

The shipment inspection step 57 is a step of re-measuring the dimensions of the portions measured in the receipt inspection step 57 with respect to the surface of the baked lower electrode 16 and comparing them with each other. In a preferred embodiment, the inspection in this step 57 is, for example, selected embossing of 16 points among the plurality of embosses constituting the structure of the embossing 20 of the lower electrode 16, as measured at the receipt inspection. The height of the boss area, for example the surface roughness of the selected part of 16 points, the edge part of the lower electrode 16 without embossing, that is, the roughness of 8 points of the dam, for example, the location and condition of the damaged part of the embossing and dam, etc. Each can be measured. This measurement data can then be compared with the data examined in the goods receipt inspection step 51.

As a result of the present inventors practicing the method of removing the foreign matter of the lower electrode 16 through the above-described method, the period of time usually takes about 3 to 4 days, and the foreign matter is satisfied while hardly damaging the surface embossing structure. It could be confirmed that it is removed. This is not only a conventional two-week spraying of aluminum oxide powder with a spray gun to remove foreign matters, but also a cost reduction compared to the risk of damage to the surface embossing structure. It is easily understood that it is very economical.

Although the present invention has been described through specific embodiments, various modifications are possible to those skilled in the art by referring to and combining various features described herein. Therefore, it should be pointed out that the scope of the present invention should not be limited to the described embodiments, but should be interpreted by the appended claims.

As described above, the present invention is in the field of regeneration for removing and reusing foreign substances in the lower electrode having an embossed structure of an etching chamber for etching a target object in order to manufacture a semiconductor device such as a liquid crystal display (LCD). Available.

1 is a schematic view showing the configuration of an etching chamber of a typical semiconductor manufacturing equipment.

Figure 2 is a schematic diagram for explaining the embossing structure of the conventional etching chamber lower electrode.

3 is a schematic view for explaining a spray gun method for regeneration of a conventional etching chamber lower electrode.

4 is a schematic view for explaining a cleaning method for regeneration of the etching chamber lower electrode according to an embodiment of the present invention.

5 is a flowchart illustrating a process of a cleaning method for regeneration of an etch chamber lower electrode according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10: etching chamber

12: to-be-processed object

14: upper electrode

16: lower electrode

20: embossing

22: film

30: foreign matter

40: spray gun

100: cleaning liquid

Claims (2)

A cleaning method 50 for regenerating a lower electrode 16 in a semiconductor equipment etching chamber, A receipt inspection step 51 of measuring a dimension of a predetermined portion of the lower electrode 16 separated from the etching chamber; The surface of the lower electrode 16 received and inspected was mixed with potassium hydroxide (KOH): hydrogen peroxide (H2O2): deionized water (DIW) from 7 to 13 parts by weight: 7 to 13 parts by weight: 42 to 78 parts by weight. Washing with 10 to 60 minutes and then washing with purified water for 30 to 60 minutes; The surface of the pre-treated lower electrode 16 was washed with a solution mixed with hydrofluoric acid (HF): nitric acid (HNO3): purified water 7 to 13 parts by weight: 7 to 13 parts by weight: 210 to 390 parts by weight for 10 minutes to 60 minutes. After washing step (53) for washing 30 to 60 minutes with purified water; Neutralization step of washing the surface of the lower electrode 16 washed 10 to 60 minutes with a solution mixed with acid neutralizer: 7 to 13 parts by weight: 7 to 13 parts by weight of purified water, and then 30 to 60 minutes with purified water 54; A post treatment step 55 of washing the surface of the neutralized lower electrode 16 with alcohol for 30 to 60 minutes; Baking the surface of the post-treated lower electrode 16 at room temperature for 10 to 30 minutes, and then leaving it in a fan flow environment at 20 to 60 degrees for 3 to 10 hours; And A factory inspection step 57 for re-measuring the dimensions of the portions measured in the receipt inspection step 51 with respect to the surface of the baked lower electrode 16 is compared with each other. A cleaning method for regeneration of a lower electrode in an etch chamber of a semiconductor device comprising a. The method of claim 1, wherein the inspection in the goods receipt inspection and the shipment inspection steps (51, 57) is performed by the height of the selected embossed portion of the lower electrode 16, the surface roughness of the selected portion, and the lower electrode 16 without embossing. A method for cleaning regeneration of a lower electrode in an etch chamber of a semiconductor device, characterized in that it comprises an edge portion of the dam, ie, roughness of the dam, embossing and damage of the dam.

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