KR20040040104A - Loadlock Chamber with Anti-corrosive Coating Film - Google Patents

Abstract

PURPOSE: A loadlock chamber having a corrosion-preventing layer is provided to prolong the lifetime of the loadlock chamber and prevent the wafer transiently stored in the chamber from being contaminated. CONSTITUTION: A loadlock chamber of semiconductor etching equipment includes a corrosion preventing layer coated on its inner wall and the surface of a stage. Preferably, the corrosion preventing layer is made of one selected from a group consisting of Al2O3, AlC, TiN, and AIN. Preferably, the corrosion preventing layer has a thickness of 30-600 μm. Preferably, the corrosion preventing layer is completed by sequentially coating an phosphor nickel layer(31) and a ceramic layer(32) on the surface(21) of the chamber.

Description

Loadlock Chamber with Anti-Corrosion Film

The present invention relates to an etching apparatus, and more particularly, to a loadlock chamber for temporarily storing a wafer in a process of loading or unloading a wafer into a process chamber.

In general, a process for manufacturing a semiconductor device may be classified into a process of laminating material films, a process of patterning the stacked material films into a desired shape, a process of forming a desired pattern using a mask, and a cleaning process. Since the generation or presence of particles during this process greatly affects the yield and reliability of semiconductor devices, most of the manufacturing equipment of semiconductor devices are provided with a plurality of chambers that are sealed to perform a desired process in a vacuum atmosphere. Selective loading / unloading of the wafer into the chamber of.

Figure 1 shows a general etching equipment. As shown in FIG. 1, the etching apparatus is composed of a plurality of process chambers 11, a transfer chamber 12, a load lock chamber 13, an alignment chamber 14, and the like.

The transfer chamber 12 is provided with a wafer transfer robot having a wafer transfer arm on an inner bottom surface thereof, and a chamber lid is coupled to the upper side to seal the transfer chamber. O-ring is installed. The chamber lead is formed with a coupling hole in which the upper end of the wafer transfer robot is coupled to the center, and an O-ring is installed at the coupling portion for sealing. In addition, the chamber lid is provided with a plurality of view porters formed of a quartz material to observe the inside of the transfer chamber around the coupling hole.

The outer side of the transfer chamber 12 of this structure is formed with a plurality of side surfaces in the form of a polygon, each of the plurality of process chambers (process chamber 11) and a process chamber for proceeding a desired process in a high vacuum state, A loadlock chamber 13 which temporarily stores the wafer prior to loading the wafer into (11) or temporarily stores the wafer which has been subjected to the process from the process chamber, the flat zone of the wafer before being loaded into the process chamber. There is an alignment chamber 14 for aligning the zones.

Each side of the transfer chamber 12 includes a slit and a valve for passing a wafer for loading / unloading the wafer from the transfer chamber 12 into a process chamber, a load lock chamber, an alignment chamber, and the like. The wafer transfer robot vacuum-adsorbs the wafer to the wafer transfer arm to load / unload the wafer into the process chamber, the load lock chamber, the align chamber, and the like through the respective slits.

In the etching apparatus having such a structure, the load lock chamber has an effect of alternating between atmospheric pressure and vacuum. In the case where a process is performed on a wafer in a high vacuum chamber, the wafer is not transferred directly into the process chamber in which the process is performed, but the wafer is transferred to the process chamber after the load lock chamber. This is to create a stable high vacuum state of the main chamber in order to perform the process, after loading the wafer into the load lock chamber and then forming the load lock chamber in a vacuum state, if a predetermined vacuum is set on one side of the load lock chamber The wafer is transferred to the process chamber through a slit that opens and closes the process chamber and the load lock chamber to maintain the high vacuum atmosphere of the process chamber. Semiconductor processes performed in high vacuum chambers include dry etching, ion implantation, chemical vapor deposition, and the like.

On the other hand, for example, bulk gases and toxic gases are used as the gas used when dry etching is performed in the process chamber, and among them, gases having corrosive properties are used. These corrosive gases are used only in the process chamber, but after the etching process, the corrosive gas component may remain on the surface of the wafer, and this residual corrosive gas not only affects the component life of the load lock chamber, the alignment chamber, etc. Metallic debris falls from each corroded part, resulting in poor wafer yield. In particular, the wall and the stage of the load lock chamber are made of pure aluminum, and are highly affected by the corrosive gas used in the process chamber. As a result, when corrosion occurs in the load lock stage, all parts are discarded after replacement, and when corrosion occurs on the wall, it is difficult to replace the wall assembly. Wet cleaning removes the corrosion gas residues and corroded parts. . However, as the service life of the equipment increases, contamination by the corrosion of the load lock chamber occurs more seriously.

The present invention is to solve this problem, to prevent the corrosion of the load lock chamber caused by the corrosive gas used in the process chamber to extend the life of the load lock chamber, and also to provide a temporary storage of the wafer It is aimed at increasing the yield of the wafer by preventing contamination.

1 is a schematic view of a general etching equipment,

2 is a structure in which a corrosion resistant coating film is coated on aluminum, and

3 shows a coating structure in which an nickel plated film and a ceramic coating film are deposited.

Explanation of symbols on the main parts of the drawing

11: process chamber 12: transfer chamber

13: Load lock chamber 14: Align chamber

21: aluminum surface 22: corrosion protection film

31: nickel layer 32: ceramic layer

In order to achieve this object, the present invention is to coat the inner wall and the stage of the load lock chamber in order to prevent contamination of the load lock chamber to increase the corrosion resistance by the residue of the corrosive gas to the metal by corrosion in the load lock chamber Provided is a load lock chamber having a structure that reduces foreign matter generation such as particles and prolongs the life of a part.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The corrosive gas used in the etching process is a toxic gas such as HB _r , BCl ₃ , Cl ₂ , etc.The inner wall surface of the load lock chamber and the components of the stage are made of pure aluminum. Vulnerable to Therefore, the coating film is coated so that the inner wall and the stage of the load lock chamber have corrosion resistance to corrosive gas.

2 shows a structure in which aluminum is coated with a corrosion resistant coating. As shown in Fig. 2, a corrosion preventing film 22 is formed on the inner wall surface of the load lock chamber made of aluminum 21 or the like and on the surface of the stage. Here, the corrosion preventing film 22 is composed of Al ₂ O ₃ , AlC, TiN, TiC, AIN and the like. The coating of the anti-corrosion film 22 is coated by, for example, flame spray, ceramic spraying, anodizing coating, Tefron coating, or the like. Here, the thickness of the corrosion prevention film 22 is 30-600 micrometers, Preferably it is 100-500 micrometers.

3 shows a coating structure in which an nickel plated film and a ceramic coating film are deposited. As shown in Fig. 3, the wall and stage surfaces of the load lock chamber are composed of anodized or unanodized aluminum. The coating according to the invention allows the use of higher purity aluminum as well as more economical aluminum alloys, regardless of the composition, grain structure or surface conditions. The nickel coating film 31 and the ceramic coating film 32 are laminated on the surface 21 of this aluminum.

According to the present invention, phosphorus on the aluminum surface 21 can be used using a variety of techniques including, for example, plating methods such as electroless and electroplating, sputtering, immersion coating or chemical vapor deposition. The nickel layer 31 is coated. The electroless coating method is a preferred method of providing a phosphorus nickel (P-Ni: 31) coating film as a method of plating a complex inner surface of a chamber without using current. Examples of techniques for the electroless coating of P-Ni alloys are disclosed in US Pat. No. 4,636,255, which is incorporated herein by reference. Here, for easy adhesion of the material to be coated, it is preferable that the surface of the aluminum 21 completely remove surface material such as an oxide film or grease before coating. The phosphorus nickel alloy is intended to comprise 9 to 12 weight percent, preferably about 10 to 12 weight percent phosphorus (P). And the phosphorus nickel coating film 31 is 20-400 micrometers, Preferably it is 100-300 micrometers in thickness.

After the phosphorus nickel coating layer 31 is coated on the aluminum surface 21, the phosphorus nickel coating layer 32 is roughened by blasting or the like to coat the ceramic material layer 32. The phosphorus nickel coated film 31 having a roughened surface provides good bonding with the molten ceramic particles. The ceramic material is thermally sprayed onto the phosphorus nickel coating layer 31, and then a high mechanical compressive force is applied to the phosphorus nickel coating layer 31 that is roughened as the ceramic coating layer is cooled, thereby causing cracks in the ceramic coating layer 32. Minimize that. The ceramic coating layer 32 is made of a ceramic material or a combination of materials such as Al ₂ O ₃ , SiC, Si ₃ N ₃₄ , BC, AlN, TiO _2, and the like.

The ceramic coating layer 32 may use a deposition technique such as chemical vapor deposition or RF sputtering, and a preferred coating method is to use a thermal spraying method that combines the molten ceramic powder by a gas flow directed to a target component. desirable. Conventional thermal spray techniques, including plasma sprays, are introduced in The Science and Engineering of Thermal Spray Coatings (John Wiley, 1995) by Pawlowski. The ceramic coating film 32 is about 20 to 600 µm, preferably about 50 to 300 µm.

On the other hand, the total thickness of the phosphorus nickel coating film 31 and the ceramic coating film 32 coated on the aluminum surface is 30 to 600 ㎛, preferably 100 to 500 ㎛.

Although the configuration of the present invention has been described in detail with reference to the above embodiments, the embodiments of the present invention are not limited thereto, and include various modified forms falling within the scope of the embodiments and equivalents thereof.

According to the coating film formed according to this structure or method, it is possible to prevent the corrosion of the load lock chamber caused by the corrosive gas used in the process chamber to extend the life of the load lock chamber, and also temporarily stored in the load lock chamber It is possible to increase the yield of the wafer by preventing contamination of the wafer.

Claims (7)

In the load lock chamber of the etching equipment used for semiconductor manufacturing, The load lock chamber of the semiconductor etching equipment, characterized in that it comprises an anti-corrosion coating coated on the inner wall and the stage surface of the load lock chamber. The method of claim 1, wherein the corrosion preventing film The load lock chamber of the semiconductor etching equipment, characterized in that the material of Al ₂ O ₃ , AlC, TiN, TiC and AIN. The method of claim 2, wherein the corrosion preventing film The load lock chamber of the semiconductor etching equipment, characterized in that the coating to a thickness of 30 to 600 ㎛. The method of claim 1, wherein the corrosion preventing film An nickel layer coated on the surface of the chamber; And The load lock chamber of the semiconductor etching equipment, characterized in that consisting of a ceramic layer coated on the nickel coating film. The method of claim 4, wherein the corrosion preventing film The nickel layer has a thickness of 20 to 400 ㎛, and the ceramic layer is 20 to 600 ㎛ coated load lock chamber, characterized in that the coating. The method of claim 5, wherein the corrosion preventing film Load lock chamber of the semiconductor etching equipment, characterized in that the total thickness of 30 to 600㎛. The corrosion preventing film according to any one of claims 1 to 6, wherein The load lock chamber of the semiconductor etching equipment, characterized in that formed on the inner wall and the stage surface of the load lock chamber.