KR20070072777A - Low pressure chemical vapor depositor - Google Patents

Abstract

A low-pressure chemical vapor deposition apparatus is provided to suppress leakage of reactive byproducts between a flange and an exhaust unit by integrating the flange with the exhaust unit. A reaction tube is formed to perform a deposition process on a wafer. A flange(61) is formed to support the reaction tube. An exhaust unit(74) is integrated with the flange. One side of the flange penetrates the exhaust unit. A flow path(62) is formed in the inside of the flange in order to cool a sealing member(63). A cooling water supply tube is connected to one end of the flow path. A cooling wafer collection tube is connected to the other end of the flow path.

Description

Low pressure chemical vapor depositor

1 is a schematic view of a typical low pressure chemical vapor deposition apparatus.

2 is a cross-sectional view of the flange of FIG.

3 is a plan view showing the flange and the exhaust coupled to the flange of FIG.

4 is a schematic view of a low pressure chemical vapor deposition apparatus according to the present invention;

5 is a cross-sectional view of the flange of FIG.

6 is a plan view showing the flange and the exhaust coupled to the flange of FIG.

* Description of the symbols for the main parts of the drawings *

51. Inner Tube 53. Outer Tube

55. Reaction tube 57. Wafer

59. Boat 61. Flange

60. Pedestal 62. Euro

63. Sealing member 66. Cooling water supply pipe

67. Coolant recovery pipe 71. Source gas supply

74. Exhaust part 76. Vacuum line

The present invention relates to an apparatus for manufacturing a semiconductor device, and more particularly to a low pressure chemical vapor depositor for forming a thin film on a plurality of wafers.

As generally known, an Atmosphric Pressure Chemical Vapor Deposition process was mainly performed to increase the yield of thin film deposition. In the case of such atmospheric chemical vapor deposition, since the deposition process proceeds in a state where a plurality of wafers are stacked, the reactors do not reach properly between the wafers, and thus the uniformity of the thin film deposition is very poor. Therefore, in order to solve this problem, a low pressure chemical vapor deposition process has been proposed. Unlike conventional atmospheric chemical vapor deposition processes that deposit thin films near atmospheric pressure, low pressure chemical vapor deposition processes deposit thin films by chemical vapor deposition in a low pressure range of 0.1 to 50 torr. In the low pressure chemical vapor deposition process, since the chemical vapor deposition process proceeds under a low pressure of the reactor gas, the mean free path of the reactor gases is long. Therefore, in the case of the low pressure chemical vapor deposition process, the reactants flow well between the wafers, thereby improving the uniformity of the thin film deposition, and also improving the step coating property, so that contact holes and trenches can be filled without voids. Therefore, the low pressure chemical vapor deposition process is widely used in the actual semiconductor device manufacturing process because of the above advantages.

1 is a schematic view showing a general low pressure chemical vapor deposition apparatus. 2 is a cross-sectional view of the flange of FIG. 1, and FIG. 3 is a plan view of the flange and the exhaust unit coupled to the flange of FIG. 1.

As shown in FIG. 1, a general low pressure chemical vapor deposition apparatus includes a reaction tube 5, a flange 11, and an exhaust 24.

1 and 2, the reaction tube (5) has a double structure of the inner tube (3) and the outer tube (1) surrounding the inner tube (3). Inside the inner tube 3 a boat 9 on which wafers 7 are loaded is arranged. The pedestal 10 is disposed below the reaction tube 5. The pedestal 10 supports the reaction tube 5. The pedestal 10 is disposed such that a portion corresponding to the center of the reaction tube 5 is opened and is in contact with a portion corresponding to the outer portion of the reaction tube 5. The flange 11 is coupled to the reaction tube 5 while being inserted into the opened center of the pedestal 10. Between the flange 11 and the reaction tube 5 is inserted a first sealing member 13 for sealing them from the outside. The first sealing member 13 may be an O-ring. The first sealing member 13 is made of a synthetic rubber material and vulnerable to heat, while the reaction tube 5 is maintained at a very high temperature during the process. Therefore, in order to prevent the first sealing member 13 from being damaged by overheating due to heat, one flow channel 12 through which cooling water flows is formed inside the flange 11. The flow path 12 may be disposed along a portion corresponding to the first sealing member 13.

During the low pressure chemical vapor deposition process, it is very important that the first sealing member 13 is cooled to an appropriate temperature. For example, the gas introduced through the source gas supply unit 21 rises upwardly and is supplied into the reaction tube 5. When the amount of cooling water is insufficient, the first sealing member 13 is deformed due to overheating. Due to the sealing between the outer tube 1 and the flange 11 is not made properly, leakage occurs in the reaction tube (5). On the other hand, when the amount of cooling water is large, a large amount of process gas is deposited on the inner wall of the reaction tube 5 or the flange 11 adjacent to the flow path 12, which later acts as particles to cause process defects. Therefore, in order to ensure that the cooling water in the flow passage 12 is always smoothly supplied by an appropriate amount, as shown in FIG. The recovery pipe 17 is connected. That is, the cooling water supply in the flow path 12 can be properly adjusted through the cooling water supply pipe 16 and the cooling water recovery pipe 17.

The flange 11 has an opening (not shown) of a predetermined size at one side, and is coupled to one end of the exhaust part 24 through the opening. The exhaust part 24 may be an exhaust pipe. The exhaust part 24 is screwed with the flange 11. The gaseous reaction byproduct in the reaction tube 5 is exhausted to the exhaust part 24 through the flange 11. A second sealing member 25 may be interposed between the flange 11 and the exhaust part 24 for sealing therebetween. The second sealing member 25 may be an O-ring. The other end of the exhaust part 24 is connected to the vacuum line 26.

However, in the existing apparatus, by taking a structure in which the flange and the exhaust part are separated, various problems described below arise.

Since the actual low temperature chemical vapor deposition process proceeds at a high temperature of 700 to 780 ° C, the second sealing member may be deteriorated by heat. In this case, the second sealing member may not properly perform the sealing role. Therefore, while the reaction by-products in the reaction tube are exhausted through the exhaust part, some of the reaction by-products leak into the gap between the flange and the exhaust part. In particular, when the process is performed using the H 2 gas in the inner tube, it may explode if the sealing is not properly.

Accordingly, in the low pressure chemical vapor deposition apparatus, there is a need for a low pressure chemical vapor deposition apparatus capable of increasing the sealing effect between the flange and the exhaust portion and minimizing deformation due to heat.

The present invention is to solve the above problems, to provide a low pressure chemical vapor deposition apparatus that can improve the flange structure to minimize the deformation caused by heat and to increase the sealing effect between the flange and the exhaust.

To solve the above problems, the present invention provides a low pressure chemical vapor deposition apparatus. The low pressure chemical vapor deposition apparatus includes a reaction tube undergoing a deposition process on a wafer, a flange supporting the reaction tube, and an exhaust part integrally formed with the flange while penetrating one side of the flange.

It may be further provided with a flow path formed in the flange, the cooling water for cooling the sealing member.

The flow path is preferably connected to the cooling water supply pipe is connected to one end and the cooling water recovery pipe is connected to the other end.

The reaction tube is preferably made of quartz.

Preferably, the exhaust part is an exhaust pipe.

The exhaust pipe is preferably made of sus material.

The exhaust unit is preferably connected to a vacuum line.

(Example)

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed subject matter is thorough and complete, and that the spirit of the present invention to those skilled in the art will fully convey.

4 is a schematic view of a low pressure chemical vapor deposition apparatus according to the present invention. 5 is a cross-sectional view of the flange of FIG. 4, and FIG. 6 is a plan view of the flange and the exhaust unit coupled to the flange of FIG. 4.

As shown in FIG. 4, the low pressure chemical vapor deposition apparatus according to the present invention includes a reaction tube 55 and an exhaust portion 74 and an integral flange 61.

The reaction tube 55 has a double tube structure of an inner tube 53 and an outer tube 21 surrounding the inner tube 53. The boat 59 is disposed inside the inner tube 53. The boat 59 may have a plurality of wafers 57 loaded therein. The wafers 57 loaded in the boat 59 are loaded at predetermined intervals so that the process gas flows therebetween. The boat 59 may be rotated by a separate rotating means (not shown) during the deposition process. As a result, the flow of the process gas supplied between the wafers 57 can be made uniform. Since the inner tube 53 and the outer tube 51 are made of quartz, they are stable to heat during the deposition process. Meanwhile, in FIG. 4, reference numeral 71, which is not described, indicates a source gas supply unit.

As shown in FIG. 5, a pedestal 60 is disposed below the reaction tube 55. The pedestal 60 supports the reaction tube 55. The pedestal 60 is disposed such that a portion corresponding to the center of the reaction tube 55 is opened and is in contact with a portion corresponding to the outer portion of the reaction tube 55. The flange 61 is coupled to the reaction tube 55 while being inserted into the opened portion of the pedestal 60. The sealing member 63 is inserted between the flange 61 and the reaction tube 55. The sealing member 63 is installed on the contact surface of the reaction tube 55 and the flange 61 serves to maintain the airtight from the outside. The sealing member 63 may be an O-ring.

The low pressure chemical vapor deposition process performed in the low pressure chemical vapor deposition apparatus of the present invention proceeds at a high temperature of 700 to 780 ° C. The sealing member 63 is formed of a synthetic rubber material. The sealing member 63 of a synthetic rubber material has a property that is very vulnerable to heat. Therefore, in order to compensate for the heat-vulnerable characteristics, a flow path 62 through which cooling water flows is formed inside the flange 61 to prevent the sealing member 63 from being damaged by overheating due to heat. do. The flow path 62 may be formed in the flange 61, and may be disposed along a portion corresponding to the sealing member 63. One end of the flow path 62 is connected to the cooling water supply pipe 66, and the other end is connected to the cooling water recovery pipe 67. Therefore, the cooling water supply in the flow path 62 through the cooling water supply pipe 66 and the cooling water recovery pipe 67 may be adjusted to some extent.

The flange 61 is integrally disposed with the exhaust part 74. Specifically, the exhaust part 74 may be disposed integrally with the flange 61 while passing through one side of the flange 61. The exhaust part 74 may be an exhaust pipe. The exhaust pipe may be a sus (SUS) material to prevent corrosion. The other end of the exhaust portion 74 is connected to the vacuum line 76. The vacuum line 76 is connected to the vacuum pump (not shown). The gaseous reaction byproduct in the reaction tube 55 is exhausted through the flange 61 to the exhaust portion 74 and the vacuum line 76.

In the present invention, since the exhaust part is integrally manufactured to the flange, the reaction by-products may not leak through the gap between the flange and the exhaust part, and thus the low pressure chemical vapor deposition process may be stably performed. That is, according to the present invention, by blocking the leakage of the reaction byproduct between the flange and the exhaust source, it is possible to stably perform a low pressure chemical vapor deposition process by preventing the generation of particles caused by the reaction byproduct leakage.

Further, in the present invention, since the exhaust part is integrally manufactured to the flange, there is no need for a sealing member for sealing therebetween between the flange and the exhaust part. Therefore, it is possible to solve the problem due to the damage of the specific site by the deposition heat during the low temperature chemical vapor deposition process at a high temperature of 700 ~ 780 ℃. That is, in the present invention, a satisfactory sealing effect can be obtained by adopting the integral structure of the flange and the exhaust part.

According to the present invention, there is provided an exhaust part formed integrally with the flange while passing through the flange and one side of the flange. Therefore, by taking the integrated structure of the flange and the exhaust portion, it is possible to fundamentally block the leakage of the reaction by-product between the flange and the exhaust portion. As a result, it is possible to stably perform the low pressure chemical vapor deposition process by preventing the generation of particles caused by the reaction byproduct leakage.

In addition, in the present invention, the flange and the exhaust portion have an integrated structure, whereby the specific portion can be prevented from being damaged by heat during the low temperature chemical vapor deposition process. Therefore, there is an advantage that a satisfactory sealing effect can be obtained between the flange and the exhaust part.

Claims (7)

A reaction tube through which the deposition process is carried out on the wafer, A flange supporting the reaction tube; Low pressure chemical vapor deposition apparatus characterized in that it comprises an exhaust portion formed integrally with the flange while penetrating one side of the flange. The low pressure chemical vapor deposition apparatus according to claim 1, further comprising a flow path formed inside the flange and through which coolant flows to cool the sealing member. The low pressure chemical vapor deposition apparatus according to claim 2, wherein the flow path is connected with a cooling water supply pipe at one end thereof and connected to a cooling water recovery pipe at the other end thereof. The low pressure chemical vapor deposition apparatus according to claim 1, wherein the reaction tube is made of quartz. The low pressure chemical vapor deposition apparatus according to claim 1, wherein the exhaust portion is an exhaust pipe. The low pressure chemical vapor deposition apparatus according to claim 5, wherein the exhaust pipe is made of sus material. The low pressure chemical vapor deposition apparatus according to claim 1, wherein the exhaust part is connected to a vacuum line.

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