KR100957456B1 - Thin film layer deposition apparatus using atomic layer deposition method - Google Patents

Abstract

The present invention relates to an atomic layer deposition apparatus, comprising: a process chamber forming a constant reaction space; A wafer holder having a plurality of wafer rests formed on an upper surface thereof, an outer circumferential surface thereof contacting an inner wall of the process chamber, and a through hole formed in a central portion thereof; A gas injector positioned above the wafer holder; A gas inlet pipe passing through a part of the process chamber and connected to the gas injection device; A plurality of susceptor assemblies supporting the wafer holder; Provided is an atomic layer deposition apparatus comprising an exhaust port formed in a portion of a process chamber bottom.

According to the present invention, by uniformizing the gas pressure distribution in the process chamber, not only can the thin film uniformity be improved, but also the process time required for gas supply and purge can be shortened, thereby contributing to productivity improvement and cost reduction for production equipment. do.

Atomic Layer Deposition Equipment, ALD, Shower Ring, Wafer Holder

Description

Thin film layer deposition apparatus using atomic layer deposition method

1 is a cross-sectional view of a conventional atomic layer deposition apparatus for a plurality of wafers

2 is a plan view of an atomic layer deposition apparatus for a conventional multiple wafer

3 is a pressure distribution diagram of a conventional atomic layer deposition apparatus for many wafers

4 is a cross-sectional view of an atomic layer deposition apparatus according to an embodiment of the present invention.

5 is a plan view of an atomic layer deposition apparatus according to an embodiment of the present invention

6 is a pressure distribution diagram of an atomic layer deposition apparatus according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

20: process chamber 30: susceptor assembly

31: heater 40: wafer hold

50: wafer 60: first purge gas inlet pipe

70: source gas inlet tube 80: reaction gas inlet tube

90: second purge gas inlet pipe 100: shower ring

110: through hole 120: exhaust port                 

130: wafer support base 140: shower ring nozzle

The present invention relates to a thin film deposition apparatus using an atomic layer deposition (ALD) method capable of processing a plurality of wafers.

In order to manufacture a semiconductor chip or thin film transistor liquid crystal display (TFT-LCD), thin film deposition, etching, and cleaning on a semiconductor wafer or LCD panel (hereinafter, referred to as a substrate) must be performed. .

Such surface treatment can be divided into PVD (Physical Vapor Deposition) method using physical collision and CVD (Chemical Vapor Deposition) method using chemical reaction, such as sputtering method, CVD method is thin film compared to PVD method It is generally used because of its excellent uniformity and step coverage.

The CVD method includes APCVD (Atmospheric pressure CVD), LPCVD (Low pressure CVD), PECVD (Plasma Enhanced CVD), etc. Among them, PECVD is widely used because of the advantages of low temperature deposition and fast film formation speed.

Recently, however, the ALD method, which has a higher film uniformity or step coverage than the conventional method, requires a gate pattern, a gate oxide layer, a capacitor dielectric layer, and a diffusion barrier. It is mainly used for deposition processes such as layers).

According to the ALD method, since the reaction gases react only on the surface of the substrate, the thickness of the film deposited in one raw material supply cycle is constant. Therefore, by controlling the number of cycles of the raw material supply, there is an advantage that the thickness of the thin film can be precisely controlled.

By the way, the ALD method has to go through several to many hundreds of deposition process for thin film deposition, there is a disadvantage that takes a lot of processing time. Therefore, in the case of the deposition apparatus for semiconductor wafers, many apparatuses for processing two to four wafers at once are used in order to improve productivity.

Looking at the configuration of the atomic layer deposition apparatus for a plurality of wafers through the drawings as follows.

1 is a cross-sectional view of a conventional atomic layer deposition apparatus for processing a plurality of semiconductor wafers, Figure 2 is a plan view inside the atomic layer deposition apparatus. 1 and 2, the atomic layer deposition apparatus includes a process chamber 1 that forms a constant reaction space, a wafer holder 3 on which a plurality of wafer supports 12 are formed on an upper surface thereof, and a process chamber 1 of the process chamber 1. Located in the center of the upper surface, the injection hole (9) for injecting the process gas into the process chamber, a plurality of susceptor assembly (2) for supporting the wafer holder (3), the source gas and the reaction gas through the injection hole (9) Source gas inlet pipe 6 for supplying purge gas, reaction gas inlet pipe 7, purge gas inlet pipes 5, 8, and exhaust port 10 for discharging the reaction residual gas or purge gas to the outside. Include. The exhaust port 10 is connected to a vacuum pump (not shown) for vacuum pumping.                         

On the other hand, a heater 11 for preheating the wafer 4 is built in the susceptor assembly 2 to facilitate the deposition process.

When the thin film is deposited in the atomic layer deposition apparatus as described above, first, the wafer 4 is seated in the process chamber 1 and then sealed, and in order to remove impurities introduced into the wafer 4 during the loading process. The process chamber 1 is exhausted. Thereafter, the source gas introduced from the source gas inlet pipe 6 is sprayed into the process chamber 1 and adsorbed onto the surface of the wafer 4, and when the adsorption process is completed, Ar, N _2, etc. from the purge gas inlet pipe 5 The purge process removes residual gas by introducing purge gas.

After the purge process is completed, when the reaction gas introduced from the reaction gas inlet pipe 7 is injected into the process chamber 1 again, the source gas already deposited on the wafer 4 and the newly introduced reaction gas react. A new compound thin film will be formed. As described above, when the purge gas is introduced from the purge gas inlet pipe 8 to remove the residual gas, one thin film deposition cycle is completed. By repeating this process, an atomic layer thin film of a desired thickness can be formed.

1 and 2 indicate the direction in which the injected gas flows, and it can be seen that the gas flows laterally from the center of the chamber.

However, according to this method, since the thin film is deposited thickly in the region close to the injection hole 9 located in the center of the upper surface of the process chamber 1, the uniformity of the thin film is lowered. .

In addition, since the injected gas flows to the edge of the process chamber 1, the partial pressure of the gas decreases toward the edge of the process chamber 1.

(h는 가스가 유동하는 챔버의 높이)로 표시할 수 있으므로, 중심으로부터 멀어질수록 즉 r이 커질수록 가스가 지나는 단면적 A도 커지게 되기 때문이다.Assuming that the shape inside the process chamber 1 is cylindrical, the cross-sectional area A through which the gas passes at a distance r from the center is

(h is the height of the chamber through which the gas flows), so that the further away from the center, that is, the larger r, the larger the cross-sectional area A through which the gas passes.

3 illustrates a phenomenon in which the gas pressure decreases as the distance from the center increases.

This phenomenon results in worse step coverage or step coverage of the reaction gas toward the edge of the wafer holder 3, and to improve this, the reaction gas must be supplied for a long time.

However, if the purge time and the gas supply time are long in expensive equipment such as an atomic layer deposition apparatus, there is a problem in that the throughput per unit time is greatly reduced.

The present invention is to solve this problem, as well as to improve the thin film uniformity, and to reduce the process time to increase the productivity and cost reduction for the production equipment using a thin film deposition apparatus using a multi-wafer atomic layer deposition method Its purpose is to provide.

The present invention to achieve the above object, the process chamber for forming a reaction space; A wafer holder installed inside the process chamber and having a plurality of wafer rests formed on an upper surface thereof, and having through holes formed in a central portion thereof; A gas injection device disposed above the wafer holder and installed on an inner surface of the process chamber; A gas inlet pipe connected to the gas injection device; A thin film deposition apparatus is connected to the through hole of the wafer holder and includes an exhaust port formed in the lower portion of the process chamber.

In another aspect, the present invention provides a thin film deposition apparatus which is located inside the side wall of the process chamber, and includes a gas injection device of a shower structure having a plurality of injection holes penetrated toward the inside of the process chamber.

Hereinafter, with reference to the drawings will be described a preferred embodiment of the present invention in detail, Figures 4 and 5 shows a cross-sectional view and a plan view of the atomic layer deposition apparatus according to the present invention.

First, a plurality of susceptor assemblies 30 are installed in the process chamber 20, and a wafer holder 40 is positioned on an upper surface of the susceptor assembly 30. A plurality of wafer holders 130 may be formed on the upper surface of the wafer holder 40 to accommodate the wafer 50. The outer circumferential surface of the wafer holder 40 may be in contact with the inner wall of the process chamber 20. By installing the through hole 110 in the center, the supply gas is exhausted through the exhaust port 120 in the lower portion through the through hole 110 of the center.

On the other hand, the number of the susceptor assembly 30 may correspond to the number of the wafer set up 130, but if one susceptor assembly 30 is connected to the plurality of wafer set up 130, the number of the susceptor assembly 30 is the same. You can't.

A plurality of holes may be formed in the wafer support 130 so that a lift pin (not shown) for driving up and down may pass when the wafer 50 is loaded or unloaded, and the driving unit for driving the lift pin is a general process. Located outside the chamber and connected to the susceptor assembly 30.

In view of the volume of the chamber, the number of wafer supports 130 is generally preferably about 2 to 4, but is not limited thereto. In the susceptor assembly 30, a heater block is usually used to promote a deposition process. 31 is built in.

In addition, the gas injection unit is not formed as a single injection port as shown in FIG. When supplied, the supplied gas was dispersed into the tubular shower ring 100, and then injected into the process chamber 20 through a plurality of shower ring injection holes 140 formed in the shower ring 100.

Although FIG. 5 illustrates the number of eight shower ring nozzles 140 formed in the shower ring 100, the number of the nozzle holes may be uniform, so that the number of the nozzle holes may be uniform, it is not limited thereto. However, when the position of the injection hole is biased in part, the uniformity of injection gas is reduced, so the arrangement of the injection hole should be uniform.                     

Gas injected into the process chamber 20 through the shower ring 100 is supplied through a source gas inlet pipe 70, a reaction gas inlet pipe 80, or a purge gas inlet pipe 60, 90.

In the drawings, the shower ring 100 is illustrated as being formed inside the sidewall of the process chamber 20. However, since the shower ring 100 is merely an example, the shower ring 100 may be modified in various forms by those skilled in the art. For example, a configuration such as installing a separate shower ring on the inner wall of the process chamber 20, or installing a plurality of injectors can be expected.

In the atomic layer deposition apparatus having such a configuration, gas flows in the direction of the arrow shown in FIGS. 4 and 5, that is, from the edge of the wafer holder 40 to the center through hole 110.

In this flow, the partial pressure of the gas increases toward the center, but since the gas is exhausted through the through hole 110 in the center to the lower exhaust port 120, a uniform gas partial pressure may be formed as a whole.

6 shows the pressure distribution of the supply gas according to the distance from the center in the atomic layer deposition apparatus having the above configuration, it can be seen that a uniform partial pressure is formed regardless of the distance.

Therefore, the thin film is uniformly deposited due to the uniform partial pressure, and thus, there is no need to lengthen the gas supply time or the purge time as in the prior art, and thus the productivity is improved overall.

In the above description of the preferred embodiment of the present invention, various modifications or changes are possible by those skilled in the art, and it is natural that such modifications or changes belong to the scope of the present invention as long as they fall within the scope of the technical idea of the present invention. .

According to the present invention, by uniformizing the gas pressure distribution in the process chamber, not only can the thin film uniformity be improved, but also the process time required for gas supply and purge can be shortened, thereby contributing to productivity improvement and cost reduction for production equipment. do.

Claims (5)

A process chamber forming a reaction space; A wafer holder installed inside the process chamber and having a plurality of wafer rests formed on an upper surface thereof, and having through holes formed in a central portion thereof; A gas injection device disposed above the wafer holder and installed on an inner surface of the process chamber; A gas inlet pipe connected to the gas injection device; An exhaust port connected to the through hole of the wafer holder and formed in the lower portion of the process chamber; Thin film deposition apparatus comprising a. The method of claim 1, The gas injection device comprises a plurality of injection holes penetrated toward the inside of the process chamber. A process chamber forming a reaction space; A wafer holder in which a plurality of substrates are placed on an upper surface, and a through hole is formed in a central portion thereof; A plurality of gas injection ports formed on an inner surface of the process chamber; A gas inlet pipe passing through the process chamber and connected to the gas injection port; An exhaust port connected to the through hole of the wafer holder and formed under the wafer holder; Thin film deposition apparatus comprising a. Thin film deposition apparatus for processing a plurality of substrates, A process chamber; A gas injection device in which a gas injection port is formed on an inner wall of the process chamber; A wafer holder in which the plurality of substrates are placed, and a through hole in which a gas introduced into the process chamber through the gas injection port is exhausted is installed at a central portion thereof; An exhaust port connected to the through hole of the wafer holder and formed under the wafer holder; Thin film deposition apparatus comprising a. A thin film deposition apparatus comprising a gas ejection apparatus including a gas ejection opening on a process chamber, an inner wall of the process chamber, and a wafer holder for placing a plurality of substrates. The wafer holder includes a through hole at a central portion thereof, and an exhaust port connected to the through hole so that gas injected into the process chamber through the gas injection hole flows into the through hole. Thin film deposition apparatus comprising a.

Images