JP3873498B2 - Vapor phase epitaxial growth method and growth apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vapor phase epitaxial growth method and apparatus in which a susceptor in which a substrate is set in a glove box is vapor-phase grown in a reaction furnace, cooled after growth and a wafer (growth substrate) is taken out in the glove box, The present invention relates to a technique for obtaining a continuous and efficient growth cycle of a substrate in units of susceptors by a MOVPE (Metal Organic Vapor Phase Epitaxy) method.
[0002]
[Prior art]
A conventional vapor phase epitaxial growth apparatus (MOVPE apparatus) is roughly composed of three chambers, a glove box 1, a transfer chamber 2, and a reaction furnace 3, as shown in FIG. In FIG. 4, the arrows represent the susceptor transport path.
[0003]
In the manufacturing process, first, in the glove box 1, the semiconductor substrate is set on a susceptor as a wafer support. In the transfer chamber 2, there is a mechanism (transfer arm) that turns and travels forward and backward to transfer the susceptor, thereby transferring the susceptor to the reaction furnace 3 and heating it. A source gas, a doping source, and a dilution gas are supplied onto the heated substrate to vapor-phase grow a semiconductor crystal. During the growth, since the wafer and the susceptor become very hot in the reaction furnace, they are transferred to the glove box 1 after waiting for the temperature of the susceptor to drop after the growth. Therefore, the grown substrate (wafer) is taken out, a new substrate is set, and then transferred to the reactor again to grow. At this time, the susceptor is not exposed to the atmosphere, but there is some contamination due to the nitrogen atmosphere in the glove box 1 and the gas generated from the gloves for setting the substrate and taking out the wafer. Gas transfer is performed in the transfer chamber 2 before the transfer to the transfer chamber. Therefore, the reactor 3 can always be grown while keeping the susceptor in high purity.
[0004]
[Problems to be solved by the invention]
However, in the MOVPE method, a semiconductor crystal is vapor-phase grown by a thermal decomposition reaction, so that it is necessary to heat the susceptor to a very high temperature in a reaction furnace. On the other hand, when the wafer is taken out, the normally used wafer case and wafer tweezers melt at a high temperature, so the susceptor must be cooled. Conventionally, since a series of operations is performed from the setting of the substrate to the removal of the wafer, the non-growth time such as this cooling time lengthens one cycle from the growth to the next growth, thereby hindering throughput improvement.
[0005]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems and to shorten the wafer cooling time and the wafer take-out / substrate setting time after the growth or to improve the throughput while keeping the susceptor in high purity. .
[0006]
[Means for Solving the Problems]
(1) In order to achieve the above object, the vapor phase epitaxial growth method of the present invention is such that a susceptor having a substrate set in a glove box is vapor-phase grown in a reaction furnace, the grown susceptor is cooled, and a wafer is taken out in the glove box. In the vapor phase epitaxial growth method, a cooling chamber that can store two or more susceptors is provided between the reaction furnace and the glove box, and the substrate set on the first susceptor is vapor-phase grown in the reaction furnace. Then, the second susceptor in which the substrate is set in the glove box is transferred to the cooling chamber, where it is kept waiting for the next growth, and after the growth in the first susceptor is completed, the first The susceptor is exchanged between the susceptor and the second susceptor waiting for growth in the cooling chamber, and the growth is performed during the growth in the second susceptor. Only the first susceptor is cooled, the substrate is taken out, and the substrate is set, and the first susceptor is sent again to the cooling chamber and waits for the next growth. ).
[0007]
Conventionally, growth and a series of operations are performed from substrate setting to wafer removal. However, according to the method of the present invention, three operations of “cooling”, “wafer removal”, and “substrate setting” are performed between the three operations. This transfer can be performed during growth on one susceptor and can be separated from a series of operations. Therefore, the actual growth operation can be performed one after another by simply replacing the reactor susceptor with a standby one.
[0008]
In this vapor phase epitaxial growth method, it is preferable that a temperature sensor is provided in the cooling chamber, and the susceptor is taken out from the cooling chamber and transported to the glove box when the temperature of the susceptor drops to a temperature at which the cooling can be taken out. ).
[0009]
(2) The vapor phase epitaxial growth apparatus of the present invention performs vapor phase growth in a vapor phase epitaxial growth apparatus that supplies a source gas, a doping source, and a dilution gas on a heated substrate and vapor-deposits a semiconductor crystal on the substrate. In addition to a reaction furnace, a transfer chamber having a transfer mechanism, a glove box for setting a substrate and taking out a wafer, a susceptor in which a substrate before growth is set while maintaining high purity by gas replacement , and cooling after growth The cooling chamber is configured to hold two or more susceptors on which the wafer is set (claim 3).
[0010]
By using this cooling chamber, the above-described growth method can be carried out, and growth can be performed alternately by two susceptors. In other words, the newly added high-purity cooling chamber is used as a waiting place for cooling the grown wafer and as a place for waiting for the growth of the susceptor on which the next growth substrate is set, so that two susceptors are used in parallel. Then, growth is performed alternately on the two susceptors. Since operations other than growth can be performed with the other susceptor during one growth, the number of growths of the vapor phase epitaxial growth apparatus can be improved.
[0011]
In the vapor phase epitaxial growth device, that make up a device for performing predominantly vapor deposition of the compound semiconductor crystal.
[0012]
In the vapor phase epitaxial growth apparatus of the present invention, the cooling chamber is preferably configured as follows. That is, the cooling chamber, one lifting mechanism for the susceptor that supports the substrate can hold two or more. Cooling chamber Ru create a highly heat-resistant material. Cooling chamber shall be the structure capable cooled an outer shell. The cooling chamber has a vacuum drawing line, a gas pipe, and a pressure gauge, and has a function of replacing the gas inside. The cooling chamber you install thermocouples As can be seen the temperature of a susceptor inside. The cooling chamber Ru attaching the monitoring window that can monitor internal from external. The cooling chamber is provided with a loading and unloading door (hatch), and replacement of the susceptor from there, that enable and facilitate the cleaning of the internal chamber.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on the illustrated embodiments.
[0014]
As shown in FIG. 1, in addition to three conventional chambers, a glove box 1 for setting a substrate and taking out a wafer, a transfer chamber 2 having a transfer mechanism, and a reactor 3 for vapor phase growth, by gas replacement A high-purity cooling chamber (cooling chamber) 4 is provided for holding a susceptor on which a substrate before growth is set under high purity and a susceptor on which a wafer being cooled after growth is set. In the case of this embodiment, the glove box 1, the transfer chamber 2, and the cooling chamber 4 are arranged linearly in the lateral direction, and the reaction furnace is arranged in a T-shape as a whole with respect to the transfer chamber 2. It is in shape.
[0015]
The high-purity cooling chamber 4 is made of a heat-resistant material so as to accommodate a susceptor that has been heated to a high temperature after growth, and the outer shell is water-cooled. In addition, a thermocouple is installed as a temperature sensor so that the temperature of the susceptor in the cooling chamber 4 can be known immediately. Furthermore, in order to maintain the atmosphere in the cooling chamber 4 with high purity, a vacuum evacuation line, a gas pipe, and a pressure gauge are provided so that gas replacement can be performed. The cooling chamber 4 has no impure gas generation source.
[0016]
The cooling chamber 4 is provided with a mechanism capable of storing two or more susceptors so that two highly purified susceptors can be alternately grown while being kept in high purity without being exposed to the atmosphere. It is.
[0017]
In this embodiment, the newly added high-purity cooling chamber 4 is used as (i) a place for waiting for cooling the grown wafer, and (ii) a place for waiting for growth of a susceptor on which the next growth substrate is set. Use two susceptors in parallel. That is, by performing growth alternately on two susceptors, operations other than growth are performed on the other susceptor during one growth.
[0018]
In FIG. 1, an arrow represents a susceptor transport path, and the transport indicated by the dotted arrow and the work surrounded by the dotted line are the back work during growth on one susceptor. All of them are not exposed to the atmosphere for transportation in the apparatus, and in addition, since the gas can be replaced in the transport chamber and the cooling chamber, it is possible to always maintain high purity.
[0019]
A specific growth process operation process (susceptor transfer process) will be described (see FIGS. 1 and 2).
[0020]
While the substrate set on one susceptor (first susceptor A) is vapor-phase grown in the reactor 3, the substrate is set on the other susceptor (second susceptor B) in the glove box 1. After that, it is transferred to the cooling chamber 4 where it is kept waiting for the next growth. When the growth in the first susceptor A is completed, the grown first susceptor A is sent from the reaction furnace 3 to the cooling chamber 4 (at this time, there are temporarily two susceptors in the cooling chamber). The second susceptor B waiting for growth is sent from the cooling chamber 4 to the reactor 3. The transfer from the reaction furnace to the cooling chamber and the transfer from the cooling chamber to the reaction furnace are continuous operations, which are referred to as “susceptor replacement” in this specification.
[0021]
During the growth in the second susceptor B, the grown first susceptor A performs “cooling”, “wafer removal”, and “substrate setting”, and then sends it to the cooling chamber 4 again for the next growth. It becomes a waiting state of waiting.
[0022]
That is, as shown in FIG. 2, in the conventional growth apparatus, the process from the substrate setting to the wafer removal is a series of growth and a series of operations. In the growth apparatus of this embodiment, “cooling” and “wafer removal” are performed. The three operations “set substrate” and the transfer between them can be performed during growth on one susceptor, and are separated from the series of operations. Therefore, the actual growth operation can be continued one after another by simply replacing the reactor susceptor. Moreover, since the gas can be replaced without going out of the apparatus, the work can always be performed while maintaining high purity.
[0023]
In the case of the present embodiment, two susceptors can be grown alternately while being kept in high purity without exposing the two highly purified susceptors to the atmosphere, and the number of times of growth is about l. It improved 4 times.
[0024]
If the optimum conditions of the present invention are examined, the cooling chamber of the present invention must be made of a heat-resistant material in order to accommodate the susceptor that has become hot after growth. Furthermore, the cooling chamber cools the outer shell, and is effective as a heat countermeasure. In addition, when the susceptor is exchanged during susceptor transfer, both susceptors may temporarily exist in the cooling chamber, and therefore the cooling chamber must be capable of accommodating two or more susceptors. In order to know whether it is okay to transport the cooling susceptor to the glove box and take out the wafer, the temperature of the susceptor in the cooling chamber is a criterion. Installation is essential.
[0025]
In the above-described embodiment, the glove box 1, the transfer chamber 2, the reaction furnace 3, and the cooling chamber 4 are arranged in a T shape as a whole, with the cooling chamber 4 added to the conventional shape. However, the present invention is not limited to this arrangement, and the cooling chamber 4 may be provided between “growth” and “wafer removal”, that is, between the glove box 1 and the reactor 3. Therefore, the layout of the four chambers of the cooling chamber, the glove box, the transfer chamber, and the reactor can be modified as shown in FIG.
[0026]
That is, in the example shown in FIG. 3A, the cooling chamber 4, the transfer chamber 2, and the reaction furnace 3 are linearly arranged, and the glove box 1 is arranged so as to be T-shaped as a whole with respect to the transfer chamber 2. This is an example. In FIG. 3 (b), the glove box 1, the cooling chamber 4 and the transfer chamber 2 are linearly arranged, and the reaction furnace 3 is arranged so as to be an inverted L shape as a whole with respect to the transfer chamber 2. It is the example of arrangement | positioning. And what is shown in FIG.3 (c) is the form example which has arrange | positioned the glove box 1, the conveyance chamber 2, the cooling chamber 4, and the reaction furnace 3 linearly.
[0027]
In the above embodiment, the transfer chamber 2 is provided separately, but the transfer chamber 2 can also be used as a cooling chamber. In this case, the entire apparatus can be made compact.
[0028]
Also, the substrates to be handled are not necessarily the same size, for example, both of them are 4 inches (or 3 inches), and only one of the susceptors is switched to 3 inches (or 4 inches) and grown by the same transport as the conventional apparatus. You can also. That is, 3 inch products and 4 inch products can be grown alternately.
[0029]
【The invention's effect】
As described above, according to the present invention, the following excellent effects can be obtained.
[0030]
(1) According to the vapor phase epitaxial growth method of the first or second aspect, the second substrate is set in the glove box while the substrate set on the first susceptor is vapor grown in the reaction furnace. The susceptor is transferred to the cooling chamber and waited for the next growth there. After the growth at the first susceptor is completed, the first susceptor that has been grown in the reactor and the first waiting for growth of the cooling chamber are left. The susceptor is exchanged with the second susceptor, and during the growth on the second susceptor, the grown first susceptor is cooled, the wafer is taken out and the substrate is set, and the first susceptor is cooled again. Send to chamber and wait for next growth. That is, conventionally, from the setting of the substrate to the removal of the wafer was a series of growth and operations, but according to the method of the present invention, three operations of “cooling”, “wafer removal”, and “substrate setting” are performed. Since it is performed during growth on one susceptor, it can be separated from a series of operations. Therefore, the actual growth operation can be continued one after another by simply replacing the reactor susceptor.
[0031]
(2) According to the vapor phase epitaxial growth apparatus of the third aspect, in addition to the three chambers of the reaction furnace, the transfer chamber, and the glove box, a wafer being cooled after growth is set under high purity by gas replacement . Since a cooling chamber capable of holding two or more susceptors and a susceptor that supports a substrate before growth is provided, the cooling chamber is used as a place for waiting for cooling of the grown wafer, and the growth of the susceptor in which the next growth substrate is set. By using it as a place to wait, it becomes possible to perform growth alternately with two susceptors. Therefore, the growth and series of operations in the conventional growth, which are the “cooling”, “wafer removal” and “substrate setting” operations, and the transfer between them, are the back operations during the growth on one susceptor. It becomes possible to carry out with high purity, and the number of times of growth of the vapor phase epitaxial growth apparatus can be improved as compared with the prior art.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a MOVPE apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing a work flow of the MOVPE apparatus of the present invention in comparison with the conventional one.
FIG. 3 is a plan view showing a layout example of where the cooling chamber is arranged in the apparatus in the MOVPE apparatus of the present invention.
FIG. 4 is a schematic plan view of a conventional MOVPE apparatus.
[Explanation of symbols]
1 Glove box 2 Transport room 3 Reactor 4 Cooling chamber

Claims (3)

  In a vapor phase epitaxial growth method in which a susceptor having a substrate set in a glove box is vapor-phase grown in a reaction furnace, the grown susceptor is cooled and a wafer is taken out in the glove box, the susceptor is interposed between the reaction furnace and the glove box. A cooling chamber is provided that can store two or more substrates, and the second susceptor with the substrate set in the glove box is transferred to the cooling chamber while the substrate set on the first susceptor is vapor-phase grown in the reactor. Therefore, the system waits for the next growth, and after the growth at the first susceptor is completed, the susceptor is exchanged between the first susceptor that has been grown in the reactor and the second susceptor that is waiting for the growth in the cooling chamber. During the growth on the second susceptor, the grown first susceptor is cooled, the wafer is taken out, and the substrate is set. Vapor-phase epitaxial growth method of the first susceptor sent again to the cooling chamber, characterized in that it placed in the standby state as the next growth waiting.   2. The vapor phase epitaxial growth method according to claim 1, wherein a temperature sensor is provided in the cooling chamber, and when the temperature of the susceptor drops to a temperature at which the cooling can be taken out, the susceptor is taken out from the cooling chamber and transferred to the glove box. Vapor phase epitaxial growth method. In a vapor phase epitaxial growth apparatus for supplying a source gas, a doping source material, and a dilution gas on a heated substrate and vapor-phase-growing a semiconductor crystal on the substrate, a reaction furnace for vapor phase growth, a transfer chamber having a transfer mechanism, A cooling chamber that can hold two or more susceptors that set a substrate before growth under high purity by gas replacement , and a susceptor that sets a wafer that is being cooled after growth, in addition to a glove box that sets substrates and takes out wafers. A vapor phase epitaxial growth apparatus comprising:

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