KR20150069702A - Apparatus and Method for Cleaning Process Chamber - Google Patents

Abstract

The present invention relates to an apparatus for cleaning a process chamber for performing epitaxial growth on a wafer. The apparatus includes: a gas inlet formed to one end of the process chamber; a gate outlet formed to the other end; an upper cover and a lower cover which surrounds the upper part and the lower part of the process chamber; a susceptor for mounting the wafer; and a main shaft and a susceptor supporter arranged in the lower part of the susceptor. A gas tube for injecting etching gas is inserted into the main shaft. A through-hole with a preset size is formed in the center part of the susceptor. The gas tube injects the etching gas to the upper cover through the through-hole of the susceptor to perform an etching process on the upper cover. Therefore, the generation of an error in a measured value by a pyrometer for measuring the internal temperature of the process chamber is prevented, and a frequent change in process condictions or a stress applied to the wafer is prevented and an epitaxial wafer can be stably manufactured.

Description

Technical Field [0001] The present invention relates to a cleaning apparatus and a cleaning method for a process chamber,

The present invention relates to a method for cleaning a process chamber for depositing an epitaxial layer on a semiconductor wafer, and more particularly to a method for improving etch efficiency for a top lid within a process chamber.

Generally, a semiconductor device is formed through a series of processes such as photolithography, etching, diffusion, chemical vapor deposition (CVD), ion implantation, metal deposition, and the like selectively and repeatedly performed on a wafer do. The deposition process during these semiconductor device fabrication processes is for forming the required film quality on the wafer. However, during the deposition process for film formation, film quality or by-products are deposited not only in a desired area on the wafer but also inside the chamber in which the deposition takes place.

The sediments deposited inside the deposition chamber are peeled off as the thickness thereof increases, causing particles. The particles thus generated enter the film formed on the wafer or adhere to the film surface to act as a cause of defects of the device, thereby increasing the defective rate of the product. Therefore, it is necessary to remove the film deposited inside the apparatus before the deposit is peeled off.

In a deposition chamber of a conventional deposition facility, sediments accumulate on the inner walls of the chamber or inside the chamber during the deposition of the phase change material on each wafer, and after deposition of a predetermined number of wafers, Or the exfoliation of sediments on the surfaces of internal components begins to appear. Therefore, a cleaning process for removing sediments from the chamber regularly should be performed with a cleaning cycle of the deposition process time for a predetermined number of wafers.

The source gas for epitaxial deposition and the etching gas for cleaning the process chamber introduced into the process chamber may flow in the gas inlet and form an epitaxial deposition film on the wafer while flowing in a horizontal direction with respect to the wafer, And then exhausted to a gas outlet (Exhaust).

1 is a graph showing etching efficiency according to internal positions of the process chamber. Referring to FIG. 2, it can be seen that the flow rate of the etching gas decreases from the gas supply port where the etching gas is introduced to the gas discharge port, and the etching efficiency tends to decrease in the process chamber at the gas discharge port, So that etching of the process chamber is made non-uniform.

2 is a graph showing the temperature change inside the process chamber according to the progress of the epitaxial process. A pyrometer for measuring the temperature of the wafer during the epitaxial process is provided on the upper part of the upper lid and the lower part of the lower lid in the process chamber and the temperature of the wafer is measured in a non- Change. At this time, the pyrometer passes through the upper lid and the lower lid of the process chamber. As shown in FIG. 1, as the etching efficiency decreases toward the gas discharge port, the temperature measured by the pyrometer is distorted. As a result, the temperature inside the process chamber chamber continuously changes to compensate for the difference between the measured value and the set value.

 Referring to FIG. 2, as the temperature inside the process chamber continuously changes during the epitaxial deposition process as described above, the resistivity of the epitaxial film deposited on the wafer is continuously changed, and thus the epitaxial film of the desired characteristic is deposited The amount of the dopant to be added is continuously changed. Therefore, there arises a problem in manufacturing an epitaxial wafer having uniform properties such as resistivity.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide an apparatus and a method for measuring a temperature of a process chamber, And to provide a method for manufacturing epitaxial wafers of uniform characteristics.

An apparatus for cleaning a process chamber in which epitaxial growth is performed on a wafer, comprising: a gas inlet formed at one end of the process chamber; a gas outlet formed at the other end; An upper lid and a lower lid surrounding the upper and lower portions of the process chamber; A susceptor on which the wafer is seated; And a main shaft and a susceptor support disposed at a lower portion of the susceptor, wherein a gas tube through which an etching gas is injected is inserted into the main shaft, and a through hole is formed in a central portion of the susceptor to a predetermined size And the gas tube injects an etching gas toward the upper lid through the through hole of the susceptor to perform etching on the upper lid.

According to the present invention, the cleaning efficiency of the process chamber can be improved as a whole by increasing the etching efficiency of the upper lid while keeping the cleaning time of the process chamber the same as the conventional one.

According to the present invention, there is no error in the measurement value by the pyrometer for measuring the temperature inside the process chamber, so frequent changes of process conditions or stress applied to the wafer are prevented, and an epitaxial wafer is stably manufactured .

As the etching efficiency of the process chamber is improved, an epitaxial film having uniform characteristics can be deposited on the wafer during the epitaxial process, and the quality of the flatness and resistivity of the epitaxial wafer can be improved.

1 is a graph showing etching efficiency according to internal positions of a process chamber;
Fig. 2 is a graph showing the temperature change inside the process chamber as the epitaxial process progresses
3 is a cross-sectional view of a process chamber cleaning apparatus according to an embodiment of the present invention in an epitaxial growth apparatus
4 is a plan view of the susceptor in the epitaxial growth apparatus viewed from above.
5 is a cross-sectional view in which the dotted line portion of Fig. 3 is enlarged

The embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited to these embodiments. In describing the present invention, a detailed description of well-known functions or constructions may be omitted for the sake of clarity of the present invention.

3, the epitaxial growth apparatus 100 includes a gas supply unit 111, a gas discharge port 112, a susceptor 113, An upper liner 106, and a lower liner 107. A preheating ring 102, a susceptor support 122, a lift pin 123, and a main shaft 120.

A gas supply unit 111 connected to the gas supply line 112 is formed at one side of the epitaxial growth apparatus 100 and a gas discharge port 112 connected to the gas discharge line may be formed at the other side. 103 and an upper cover 104.

The lower liner 107 is disposed within the process chamber 105 to surround the susceptor 113 and the upper liner 106 is disposed on the lower liner 107 so as to face the lower liner 107 within the process chamber 105. [ As shown in FIG. The preheating ring 102 is formed along the inner surface of the lower liner 107 adjacent to the susceptor 113 and is disposed adjacent to the susceptor 113 so as to surround the susceptor 113 to uniformize the temperature of the gas delivered to the wafer have.

The susceptor 113 is a portion on which the wafer is mounted during the epitaxial reaction and may be in the form of a plate made of a material such as carbon graphite or silicon carbide. The susceptor 113 is supported by a susceptor support 122 formed at a lower portion of the main shaft 120 and at a main shaft 12 in the edge direction of the wafer. The susceptor may be provided with a plurality of holes through which the lift pins 123 may move up and down to seat the wafer on the susceptor 113.

The susceptor 113 and the main shaft 120 are structured to change the structure of the susceptor 113 and the main shaft 120 in order to inject the etching gas into the upper cover located on the upper surface of the susceptor through which the process gas flows in the process chamber 105. [ We propose an example.

4 is a plan view of the susceptor as viewed from above in the epitaxial growth apparatus. Referring to FIG. 4, a through hole 114 may be formed in the center of the susceptor 113. The through-hole 114 is formed to correspond to the position of the lower main shaft 120, and may be formed to have a diameter of about 3 mm.

5 is an enlarged cross-sectional view of the main shaft 120 in the single crystal growing apparatus of FIG. 5, a susceptor 113 and a portion of the main shaft 120 are shown. In the center portion of the susceptor 113, a through hole 114 having an inner diameter of about 3 mm is formed . A main shaft 120 having a predetermined space is disposed at a lower portion of the susceptor 113 at a distance of about 5 mm.

A quartz gas tube 115 having an inner diameter of about 2 mm may be inserted into the space of the main shaft 120. The height corresponding to the uppermost portion of the gas tube 115 may be formed to coincide with the upper surface of the susceptor 113. One end of the gas tube 115 may be connected to a gas supply unit (not shown). The gas supplied by the gas supply may be injected into the process chamber through the susceptor 113 through one end of the gas tube 115.

3, the gas inlet 111 is provided with a source gas for epitaxial growth and a main valve (not shown) for introducing HCL gas for cleaning the process chamber, And a slit valve (not shown) in which hydrogen gas as a carrier gas for moving the reaction gas and impurities generated during the process flows is provided at the lower end.

In the process of cleaning the process chamber, the predetermined HCL gas flowing in the main valve and the hydrogen gas flowing in the slit valve are mixed and moved through the chamber to perform etching. The etching gas is supplied to the upper lid 104 located at the upper center of the susceptor 130 at a predetermined pressure by using the gas tube 115 provided in the main shaft 120 Spray. Accordingly, the upper lid positioned above the center of the susceptor is simultaneously subjected to the etching reaction by the etching gas introduced from the conventional main valve and the slit valve and the etching due to the gas tube 115, and the etching of the gas inlet and the gas discharging section It is possible to reduce the occurrence of a deviation in the reaction.

  A pyrometer (117) is disposed above the upper lid (104) to measure the temperature inside the process chamber in a noncontact manner, and the process conditions are changed according to the measured temperature. In particular, the pyrometer 117 is located at the center of the susceptor 113 to measure the temperature of the center of the wafer, and when contaminants are deposited on the upper lid that penetrates the center of the susceptor 113, There is an error in the measured value of the measurement value. Therefore, it is preferable that the injection of the etching gas through the gas tube 115 according to the embodiment is made to the region A of the upper cover corresponding to the measurement region of the pyrometer 117.

One end of the gas tube 115 may be connected to a separate gas supply line, and an etching gas mixed with a predetermined HCl gas and hydrogen gas may be used. Therefore, the etching for the upper lid can be performed simultaneously with the etching by the HCL gas and the hydrogen gas introduced from the main valve, and no additional processing time is required. Therefore, the production yield of the wafer can be kept constant, It is possible to reduce the periodic periodical inspection period of the equipment and improve the LLS quality.

Typically, when etching is applied to the process chamber, hydrogen gas is injected from the main valve and the slit valve, respectively, and flows to the top and bottom of the susceptor. The HCL gas is injected through the main valve and mixed with the hydrogen gas to move toward the gas outlet while etching the inside of the process chamber. The amount of HCL gas and hydrogen gas can be individually controlled and the etching efficiency of the process chamber can be increased by increasing the HCL gas concentration. However, if the amount of hydrogen gas is reduced to increase the concentration of HCl gas, the movement of the etching gas toward the center of the process chamber is reduced to cause a difference in etching amount between the gas inlet and the gas discharge section, .

Accordingly, since the etching gas introduced from the gas tube provided in the process chamber center etches the upper lid, the cleaning of the inside of the process chamber can be uniformly performed, while the etching efficiency of the process chamber is increased by increasing the HCL gas concentration as described above. .

On the other hand, the HCL gas can be controlled so that the amount injected through the main valve and the amount injected through the gas tube at the center of the susceptor are the same, but in the case of hydrogen gas, Is controlled so as to be larger than the amount injected through the nozzle. The HCL gas injected through the gas tube at the center of the susceptor causes the top lid to be etched to etch the deposited contaminants and the etched and peeled contaminants must be moved smoothly toward the gas outlet. Therefore, the amount of hydrogen gas that is injected from the main valve and moves the etching gas toward the gas outlet along the upper surface of the susceptor can be set to be larger than the amount of hydrogen gas injected through the gas tube.

That is, the present invention can improve the cleaning efficiency in the process chamber as a whole by increasing the etching efficiency of the upper lid, while keeping the cleaning time of the process chamber the same as the conventional one.

In addition, since there is no error in the measurement value by the pyrometer for measuring the temperature inside the process chamber, the frequent change of the process conditions or the stress applied to the wafer can be prevented, and the epitaxial wafer can be stably manufactured.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications other than those described above are possible. For example, each component specifically shown in the embodiments of the present invention can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

113: susceptor
114: Through hole
115: gas tube
120: Main shaft

Claims (4)

CLAIMS 1. An apparatus for cleaning a process chamber in which epitaxial growth on a wafer is performed,
A gas inlet formed at one end of the process chamber, and a gas outlet formed at the other end;
An upper lid and a lower lid surrounding the upper and lower portions of the process chamber;
A susceptor on which the wafer is seated; And
A main shaft disposed at a lower portion of the susceptor and a susceptor support,
A gas tube into which an etching gas is injected is inserted into the main shaft,
A through hole having a predetermined size is formed in the center of the susceptor,
Wherein the gas tube ejects an etching gas through the through hole of the susceptor toward the top lid to perform etching on the top lid. The method according to claim 1,
And a pyrometer disposed at an upper portion of the upper lid and measuring a temperature inside the process chamber, wherein the injection of the etching gas is performed with respect to a region of the upper lid corresponding to the measurement region of the pyrometer Wherein the cleaning device is a cleaning device. The method according to claim 1,
Wherein the etching of the process chamber by the etching gas injected from the gas inlet side is performed while etching the upper cover through the gas tube. The method according to claim 1,
Wherein the amount of hydrogen gas ejected from the gas inlet side is set to be greater than the amount of hydrogen gas ejected from the gas tube in the main shaft.

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