KR100443598B1 - Apparatus for Chemical Vapor Deposition - Google Patents

Abstract

The process gas is injected into the center of the upper space of the wafer support 50 by the gas focus ring 70 installed on the inner side of the reaction chamber. The process gas cannot be lowered into the lower space of the reaction chamber 10 because of the purge gas supplied from the bottom of the reaction chamber 10. Thus, the particle source can be minimized as well as the equipment's inspection cycle can be extended. In addition, since the purge gas does not rise to the upper space of the reaction chamber 10 due to the pressure of the process gas, the CVD process is not affected by the purge gas. The process gas and the purge gas are discharged through the gas discharge port 80 which is installed in the annular groove form on the side wall of the reaction chamber (10). In the middle portion of the gas discharge port 80, the annular blocking film 85 is horizontally installed so that vortices due to the mixing of the process gas and the purge gas do not occur. Lower and upper portions of the barrier layer 85 are provided with an annular lower portion 84 and an upper portion 86 having an inner diameter larger than that of the barrier layer 85. Due to the space formed by the upper dividing layer 86 and the lower dividing layer 84, each of the process gas and the purge gas is slightly discharged from various parts, thereby further reducing the vortex phenomenon.

Description

Apparatus for Chemical Vapor Deposition

The present invention relates to a CVD apparatus, and more particularly, to a CVD apparatus capable of preventing undesired deposition of a thin film in the reaction chamber subspace, thereby acting as a particle source.

In a conventional CVD apparatus, a gas outlet is mainly provided at the bottom of the reaction chamber. Therefore, when gases which do not contribute to the thin film deposition are discharged to the outside through the gas discharge port is deposited in the reaction chamber lower space there is a problem that this portion acts as a particle generation source (source).

Accordingly, an aspect of the present invention is to provide a CVD apparatus capable of extending the equipment inspection cycle by eliminating particle sources by preventing gases that do not contribute to thin film deposition into the reaction chamber lower space.

1A and 1B are schematic diagrams for explaining a CVD apparatus according to the present invention.

<Description of Reference Numbers for Main Parts of Drawings>

10: reaction chamber 20: quartz dome

30: Belza 40: Belzaheater

50: wafer support 52: support shaft

60: wafer 70: gas focus ring

72: injection hole 74: gas supply line

80: gas outlet 82: pumping line

84: lower partition 86: upper partition

85: blocking film 87: upper gas outlet

88: lower gas outlet 90: purge gas supply port

CVD apparatus according to the present invention for achieving the above technical problem, the reaction chamber is a chemical vapor deposition process is carried out; A wafer support installed in the reaction chamber and on which a wafer is seated; A gas focus ring installed at a side surface of the reaction chamber to inject a process gas from around the wafer support to the center of the upper space of the wafer support; A purge gas supply port provided at a bottom of the reaction chamber to supply a purge gas into the reaction chamber; In order to discharge the process gas injected through the gas focus ring and the purge gas supplied through the purge gas supply port, the reaction gas is positioned below the gas focus ring and positioned at a predetermined height from the bottom of the reaction chamber. A gas outlet installed in a horizontal annular ring shape along the side wall of the chamber; One pumping line connecting the gas discharge port and the vacuum pump to each other; A barrier membrane horizontally installed in the gas outlet so that the process gas and the purge gas discharged through the gas outlet are located at the middle of the gas outlet so that they are not mixed with each other at the gas outlet inlet; A plurality of annular lower subdivision membranes which are horizontally divided to divide the gas outlet portion of the lower portion of the barrier layer into a plurality of spaces and have a larger inner diameter than the barrier layer; A plurality of annular upper dividing membranes which are horizontally divided to divide the gas outlet portion of the upper portion of the barrier layer into a plurality of spaces and have a larger inner diameter than the barrier layer; It characterized by having a.

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

1A and 1B are schematic diagrams for explaining a CVD apparatus according to the present invention.

1A and 1B, the reaction chamber 10 is a single-leaf reaction chamber in which wafers are loaded one by one, and the upper portion of the reaction chamber 10 includes a quartz dome 20. A bell jar 30 covering the quartz dome 20 is installed outside the quartz dome 20, and a bell jar heater 40 is installed inside the bell jar 30. The wafer support 50 is installed in the reaction chamber 10, and the wafer 60 is placed on the wafer support 50.

The wafer support 50 is provided with a main heater (not shown) for heating the wafer 60 to an appropriate temperature at which chemical vapor deposition can occur. The wafer supporter 50 is supported by the support shaft 52. The support shaft 52 is surrounded by the bellows 55 so that the support shaft 52 is vertically transferred by the bellows 55 even though the reaction chamber 10 The inside is kept sealed.

The gas focus ring 70 is installed at the inner side of the reaction chamber 10 to surround the side of the wafer support 50. A plurality of injection holes 72 are formed in the gas focus ring 70. Instead of the injection hole 72, an annular injection ring may be formed.

A purge gas supply port 90 for supplying a purge gas such as N2 or Ar into the reaction chamber 10 is installed at the bottom of the reaction chamber 10.

Side of the reaction chamber 10 is provided with a gas discharge port 80 for discharging the process gas injected through the gas focus ring 70 and the purge gas supplied through the purge gas supply port 90. The gas outlet 80 is located below the gas focus ring 70 and has the form of an annular groove. The gas discharge port 80 is preferably installed at the same height as the wafer support 50. The gas outlet 80 is connected to one vacuum pump (not shown) by the pumping line 82.

In the gas discharge port 80, the blocking film 85 is horizontally installed in the middle of the gas discharge port 80 so that the process gas and the purge gas are not mixed with each other. Accordingly, the gas outlet 80 is divided into a lower gas outlet 88 and an upper gas outlet 87. The purge gas injected through the purge gas supply port 90 is discharged through the lower gas discharge port 88, and the process gas injected through the gas focus ring 70 is discharged through the upper gas discharge port 87.

The gas discharge port 80 is separated into the upper and lower spaces by the blocking membrane 85 but is not completely separated, but is installed to connect the upper and lower spaces at the end of the blocking membrane 85. Process gas and purge gas entering the gas discharge port 80 is discharged to the outside through the pumping line (82).

The lower gas outlet 88 is divided into three spaces 88a, 88b, and 88c by the horizontal division of the two annular lower segmental membranes 84. The lower partition film 84 has a larger inner diameter than the blocking film 85. These spaces 88a, 88b, 88c become higher in height as they go upwards. If the lower gas outlet 88 is not divided, the purge gas is gathered in this portion at once, causing vortices. However, if there are spaces 88a, 88b, and 88c, vortices are not generated because the purge gas is sequentially discharged little by little from the space below. The upper gas outlet 87 is likewise divided into three spaces 87a, 87b and 87c by the horizontal division of the two annular upper dividing layers 86, and these spaces 87a, 87b and 87c are from top to bottom. The height gets higher as you go. The upper dividing film 87 also has a larger inner diameter than the blocking film 85.

When the process gas is injected into the gas focus ring 70 through the gas supply line 74, the co-gas is injected from the periphery of the wafer support 50 to the center of the upper space of the wafer support 50 through the injection hole 72. . The process gas injected into the center of the upper space of the wafer support 50 is uniformly distributed in the upper space of the wafer support 50 while being thermally decomposed by hitting the quartz dome 20 being heated by the bell heater. Therefore, even if the wafer 60 is large in diameter, uniform chemical vapor deposition occurs on the entire surface of the wafer 60.

Residual process gas not involved in chemical vapor deposition is discharged to the outside through the gas outlet (80). At this time, the purge gas is supplied at an appropriate flow rate through the purge gas supply port 90 to prevent the process gas from descending to the lower portion of the reaction chamber 10. Of course, purge gas should not be able to rise to the upper portion of the reaction chamber 10 by the pressure of the process gas.

Since the process gas cannot be lowered to the lower space of the wafer supporter 50 by the supply of the purge gas, it is possible to deposit a thin film on the inner wall of the lower part of the reaction chamber 10 such as the wafer supporter 50 and the support shaft 52. Is prevented. Since the purge gas cannot rise to the upper space of the wafer supporter 50, the purge gas does not affect chemical vapor deposition, and thus the uniformity and deposition rate of the thin film are not affected by the purge gas. By installing the blocking film 85, these effects are even greater.

According to the CVD apparatus according to the present invention as described above, since the process gas is not lowered to the lower space of the reaction chamber 10 by the pressure of the purge gas, the process gas is deposited in the lower space of the reaction chamber 10. You can prevent it. Thus, the particle source can be minimized, as well as the equipment's inspection cycle can be extended. In addition, since the purge gas does not rise to the upper space of the reaction chamber 10 due to the pressure of the process gas, the CVD process is not affected by the purge gas.

By installing the blocking film 85 to take a two-stage pumping structure, vortex generation due to mixing of the process gas and the purge gas is prevented. If the vortex occurs at the gas outlet 80, when the gas is stagnated somewhat, a burning phenomenon occurs due to the heat of the main heater installed in the wafer support 50. In addition, since the process gas and the purge gas are each slightly discharged from the various portions by the space formed by the upper partition 86 and the lower partition 84, the vortex phenomenon is further reduced. Emissions increase more and more toward the barrier 80.

The present invention is not limited to the above embodiments, and it is apparent that many modifications are possible by those skilled in the art within the technical spirit of the present invention.

Claims (6)

A reaction chamber in which a chemical vapor deposition process is performed; A wafer support installed in the reaction chamber and on which a wafer is seated; A gas focus ring installed on an inner surface of the reaction chamber to inject a process gas from the periphery of the wafer support to the center of the upper space of the wafer support; A purge gas supply port provided at a bottom of the reaction chamber to supply a purge gas into the reaction chamber; In order to discharge the process gas injected through the gas focus ring and the purge gas supplied through the purge gas supply port, the reaction gas is positioned below the gas focus ring and positioned at a predetermined height from the bottom of the reaction chamber. A gas outlet installed in a horizontal annular ring shape along the side wall of the chamber; One pumping line connecting the gas discharge port and the vacuum pump to each other; A barrier membrane horizontally installed in the gas outlet so that the process gas and the purge gas discharged through the gas outlet are located at the middle of the gas outlet so that they are not mixed with each other at the gas outlet inlet; A plurality of annular lower subdivision membranes which are horizontally divided to divide the gas outlet portion of the lower portion of the barrier layer into a plurality of spaces and have a larger inner diameter than the barrier layer; A plurality of annular upper dividing membranes which are horizontally divided to divide the gas outlet portion of the upper portion of the barrier layer into a plurality of spaces and have a larger inner diameter than the barrier layer; CVD apparatus comprising a. The CVD apparatus according to claim 1, wherein the reaction chamber is formed of a quartz dome on an upper portion of the reaction chamber, and a bell jar heater is installed outside the quartz dome to cover the quartz dome. The CVD apparatus according to claim 1, wherein the reaction chamber is a single-sheet reaction chamber in which one wafer support is installed and one wafer is charged. The CVD apparatus according to claim 1, wherein the gas discharge port is provided at the same height as the wafer support. The method of claim 1, wherein the height of the plurality of spaces formed by the lower portion of the subdividing film becomes higher and higher, and the height of the plurality of spaces formed by the upper portion of the dividing film gradually increases from the top to the bottom. CVD apparatus, characterized in that high. The CVD apparatus according to claim 1, wherein a heater is provided inside the wafer support.