JP4526969B2 - Vapor growth equipment - Google Patents

Description

  The present invention relates to a metal organic chemical vapor deposition apparatus (MOCVD apparatus) for growing a compound semiconductor.

  As a conventional vapor phase growth apparatus, for example, there is an MOCVD apparatus shown in FIG. 7 (see Patent Document 1). The MOCVD apparatus 100 includes a gas supply unit 106 including a first gas supply unit 102, a second gas supply unit 103, a carrier gas supply unit 104, and a dopant gas supply unit 105 on a growth chamber 101. A substrate holder 107 for mounting the substrate S is rotatably provided in the chamber 101. The first gas supply unit 102, the second gas supply unit 103, the carrier gas supply unit 104, and the dopant gas supply unit 105 are arranged apart from each other.

  The substrate holder 107 is provided with a heating means 108. A gas cooling unit 109 is interposed between the gas supply unit 106 and the substrate holder 107, and a cooling jacket 110 is provided on the side wall of the growth chamber 101. Between the lower end of the cooling jacket 110 and the substrate holding table 107, an exhaust gas passage space 112 that guides the source gas and carrier gas supplied onto the substrate holding table 107 to the discharge port 111 is provided.

  As shown in FIG. 8, the gas cooling unit 109 includes a plurality of slit-shaped gas passages 109s arranged in parallel inside an annular frame 109f, and a refrigerant passage arranged to cool each gas passage 109s from both sides. 109p. The refrigerant passage 109p is folded several times by a folded portion 109t provided in the vicinity of the frame 109f, and a refrigerant introduction port 109i is provided at the start end and a refrigerant discharge port 109o is provided at the end to constitute a cooling unit.

The gas cooling unit 109 shown in FIG. 8 includes four cooling units. The refrigerant passages 109p of the respective cooling units are set to have substantially the same length so that the source gas temperature distribution on the substrate holder 107 becomes uniform. Accordingly, units located on either side (coolant inlet port to start 109i _l, units terminating the coolant outlet port 109O _l, and start the refrigerant inlet 109i _4, the termination unit to a refrigerant outlet 109o ₄₎ found the following Compared to a cooling unit located in the center (a unit having a refrigerant introduction port 109i _{2 as} a start end and a refrigerant discharge port 109o ₂ as a termination, and a unit having a refrigerant introduction port 109i _{3 as} a start end and a refrigerant discharge port 109o ₃ as a termination) Thus, the number of times the refrigerant passage 109p is folded back is increased.

The source gas and the carrier gas supplied from the gas supply unit 106 are cooled by the gas cooling unit 109, and the source gas reacts on the substrate S installed on the substrate holder 107 heated by the heating device 108 to react with the gas. Phase growth. The exhaust gas is discharged from the discharge port 111 through the gas passage space 112.
JP 2001-506803 A

  However, in the vapor phase growth apparatus described in Patent Document 1, since the gas passage of the gas cooling unit is cooled from the refrigerant passages on both sides, it is necessary to reduce the slit interval of the gas passage in order to increase the cooling efficiency. However, if the slit interval is narrowed, the gas flow becomes worse, so there is a limit to narrowing the slit interval, and as a result, a sufficient cooling effect cannot be obtained. In addition, since the refrigerant passage of the gas cooling portion has a large number of folded portions, the pressure loss is large, and the state of the refrigerant flowing through the refrigerant passage is likely to vary depending on the location, so that the cooling capacity may be uneven.

Various source gases are supplied to the substrate holder in a state of being separated from each other. However, the gas cooling unit becomes a resistance and the gas flow is disturbed, so that the source gases are easily mixed. If the source gases are mixed before reaching the substrate, an additive compound that does not contribute to vapor phase growth on the substrate is generated. If an additive compound that does not contribute to vapor phase growth stays in the vicinity of the substrate, the concentration of the raw material gas decreases, so that the utilization efficiency of the raw material is deteriorated. Here, the additive compound is a compound in which two kinds of organic compounds are weakly bonded, or a compound in which another atomic group is bonded to an atom of an unsaturated bond (for example, indium (In) of trimethylindium (TMI) to phosphine ( (PH ₃ ) ₃ In · PH ₃ ) in which PH ₃ ) is bonded. The additive compound may be mixed into the substrate as a foreign substance and cause deterioration in quality.

Furthermore, since the cooling unit for cooling the source gas and the carrier gas and the cooling jacket for cooling the growth chamber side wall are separately configured, the apparatus configuration is complicated.
The present invention solves the above-mentioned problems in the vapor phase growth apparatus, has a high cooling capacity of the raw material gas and the carrier gas, has high utilization efficiency of the raw material gas, and can improve the quality of the growth film. An object is to provide a vapor phase growth apparatus having a simple configuration.

  In the present invention, in the growth chamber, a rotatable substrate holding table for placing the substrate, a heating means for heating the substrate holding table, and a source gas and a carrier gas provided at a position facing the substrate holding table toward the substrate In the vapor phase growth apparatus provided with a gas supply unit for supplying gas, the gas supply unit is a disc body constituting the top plate of the growth chamber, and comprises a gas inlet and a gas distribution space at the upper part of the disc unit A gas introduction part is provided, a plurality of gas jets are provided over the entire area of the lower surface of the disc body, and a gas passage that communicates the gas distribution space and the gas jets is provided in parallel with the axis of the substrate holder. An annular refrigerant jacket is formed on the outer periphery of the body, and three or more refrigerant collecting passages extending in the radial direction from the center of the disk body to the vicinity of the outer periphery are provided, and the refrigerant is discharged into the refrigerant collecting passage at the center of the disk body. Connect the outlet and the refrigerant collecting passage from the refrigerant jacket The refrigerant passage communicating, the plurality of vertical stages, and and arranged to form a cooling section for cooling the gas passage from four sides.

  According to this vapor phase growth apparatus, since the gas passage is cooled from the four sides by the refrigerant passage, the source gas and the carrier gas are sufficiently cooled. Since the refrigerant passage route from the refrigerant jacket to the refrigerant discharge port through the refrigerant passage and the refrigerant collecting passage has no excessive refraction and there is very little pressure loss, the cooling capacity is kept uniform. Since there is no cooling means between the gas outlet and the substrate holder, various source gases ejected from the gas outlet are supplied onto the substrate holder without disturbing the flow. Accordingly, it is possible to prevent the source gases from mixing with each other before reaching the substrate and to generate an additive compound, to improve the raw material utilization efficiency and to prevent the quality of the growth film from being deteriorated.

  The disc body is composed of a sector block divided into three or more and a spacer block sandwiched between the sector blocks, and the refrigerant collecting passage has both or both of the side surface of the sector block and the side surface of the spacer block. If it is composed of end face grooves formed on one side, the properties of the source gas supplied for each sector block or spacer block can be changed, and various vapor phase growth can be realized. In addition, the gas supply unit can be easily manufactured.

  For example, the disc body has a sector block for supplying a carrier gas, a first spacer block for supplying a first source gas, a second spacer block for supplying a second source gas, and a third spacer block for supplying a dopant gas. The carrier gas is supplied from the sector block, and the first source gas, the second source gas, and the dopant gas are separately supplied to the substrate holder from the three spacer blocks separated by the sector block. In addition, since each source gas is isolated by the carrier gas, it is possible to more reliably prevent mixing before reaching the substrate.

When the gas passage is branched downward from the cooling section into a plurality of branch passages and a gas outlet is provided at the lower end of each branch passage, the source gas and the carrier gas can be supplied to the substrate holder in a shower shape. Therefore, vapor phase growth on the substrate is stabilized.
When the refrigerant jacket is arranged to cool the entire side wall of the growth chamber, the cooling means are integrated, and the apparatus can be simplified.

  ADVANTAGE OF THE INVENTION According to this invention, the vapor phase growth apparatus which can improve the quality of a growth film | membrane with the high cooling capacity of source gas and carrier gas, the utilization efficiency of source gas being high, and a growth film is implement | achieved.

  1 is a longitudinal sectional view of a vapor phase growth apparatus showing an embodiment of the present invention, FIG. 2 is a plan view of a gas supply unit, FIG. 3 is a bottom view of the gas supply unit, and FIG. 4 is a sector block of the gas supply unit. 4 (a) is a plan view of the sector block, FIG. 4 (b) is a front view of the sector block, FIG. 4 (c) is a diagram showing the rear side of the sector block, and FIG. FIG. 5A is an explanatory view of a third spacer block, FIG. 5A is a front view of the third spacer block, FIG. 5B is a view showing a side surface of the third spacer block, and FIG. It is explanatory drawing of a gas jet nozzle.

  As shown in FIG. 1, the vapor phase growth apparatus includes a rotatable substrate holding table 2 on which a plurality of substrates S are placed in a growth chamber 1 surrounded by a cylindrical side wall 4, and a substrate holding table 2. And a gas supply unit 5 that is provided at a position facing the substrate holder 2 and supplies a source gas and a carrier gas toward the substrate S, and the exhaust gas in the growth chamber 1 is a substrate. It is discharged from a gap between the holding base 2 and the side wall 4 to an exhaust port (not shown).

A refrigerant jacket 20 is provided on the side wall 4 so as to cool the entire side wall, and a refrigerant supply port 21 is provided at the lower portion and a second refrigerant discharge port 24 is provided at the upper portion. An opening 20a is provided at a location facing the gas supply unit 5 of the refrigerant jacket 20, and the outer peripheral surface of the gas supply unit 5 is exposed to the refrigerant.
The gas supply unit 5 is a thick disc body constituting the top plate of the growth chamber 1. As shown in FIG. 2, the gas supply unit 5 is sandwiched between the sector block 6 divided into four and the sector block 6. It consists of one spacer block 7, second spacer block 8, third spacer block 9, and fourth spacer block 10.

A carrier gas inlet 15 is provided on the upper surface of the sector block 6, a first source gas inlet 11 is provided on the upper surface of the first spacer block 7, a second source gas inlet 12 is provided on the upper surface of the second spacer block 8, and a third spacer. A dopant gas inlet 13 is provided on the upper surface of the block 9, and a first or second source gas inlet 14 is provided on the upper surface of the fourth spacer block 10.
As shown in FIG. 3, a large number of gas outlets 19 are provided on the bottom surface of the sector block 6 over substantially the entire area.

As shown in FIG. 4, a gas distribution space 16 is formed in the sector block 6 so as to communicate with a carrier gas introduction port 15 provided on the upper surface and extend over substantially the entire upper portion of the sector block 6. The gas distribution space 16 constitutes a gas introduction part.
Further, the fan block 6 is provided with a gas passage 17 communicating with the gas distribution space 16 and the gas outlet 19 in parallel with the axis Y of the substrate holder 2.

This gas passage 17 is branched into four branch passages 18 downward from a cooling section that is surrounded by four sides of an upper refrigerant passage 25 and a lower refrigerant passage 26, which will be described later, and is cooled. A gas outlet 19 is provided (see FIG. 6).
An end surface groove constituting the refrigerant collecting passage 22 is formed on the side surface in the radial direction of the sector block 6, and the end portion 22 a is closed near the outer peripheral portion of the sector block 6.

As shown in FIG. 5, the third spacer block 9 is rectangular in cross section and the length in the longitudinal direction corresponds to the radius of the gas supply unit 5. On the bottom surface of the third spacer block 9, a large number of gas ejection ports 19a are provided over substantially the entire area.
The third spacer block 9 communicates with a dopant gas introduction port 13 provided on the upper surface, and a gas distribution space 16a is formed over substantially the entire upper portion of the third spacer block 9, and the dopant gas introduction port 13 and the gas distribution space are formed. The space 16a constitutes a gas introduction part.

The third spacer block 9 is provided with a gas passage 17 a that communicates the gas distribution space 16 a and the gas outlet 19 a in parallel with the axis Y of the substrate holder 2.
End grooves forming the refrigerant collecting passage 22 are also formed on the front surface and the back surface of the third spacer block 9, and the end portions 22 a are closed in the vicinity of the outer peripheral portion of the third spacer block 9. The gas passage 17a is branched into four branch passages 18a below the position of the refrigerant collection passage 22 so as to avoid interference with the refrigerant collection passage 22, and a gas outlet 19a is provided at the lower end of each branch passage 18a. Yes.

In addition, since the structure of the 1st spacer block 7, the 2nd spacer block 8, and the 4th spacer block 10 is common in the 3rd spacer block 9, description is abbreviate | omitted.
In the gas supply unit 5 which is a disc body formed by assembling the four sector blocks 6, the first spacer block 7, the second spacer block 8, the third spacer block 9, and the fourth spacer block 10, the center portion Thus, a total of eight refrigerant collecting passages 22 are formed, two in each of the four directions. A first refrigerant discharge port 23 is connected to the refrigerant collecting passage 22 at the center of the disk.

In the sector block 6, an upper refrigerant passage 25 and a lower refrigerant passage 26 communicating from the refrigerant jacket 20 to the refrigerant collecting passage 22 do not interfere with each other, and surround the gas passage 17 from four sides in a lattice shape in plan view. It arrange | positions so that the cooling compartment to cool may be formed.
Then, by adjusting the flow rates of the first refrigerant discharge port 23 and the second refrigerant discharge port 24, the flow of the refrigerant in the refrigerant jacket 20, the upper refrigerant passage 25, and the lower refrigerant passage 26 can be controlled.

  According to this vapor phase growth apparatus, since the gas passage 17 is cooled from the four sides by the upper refrigerant passage 25 and the lower refrigerant passage 26, it is sufficiently cooled. The passage route of the refrigerant that is supplied from the refrigerant supply port 21 and reaches the first refrigerant discharge port 23 through the refrigerant jacket 20, the upper and lower refrigerant passages 25 and 26, and the refrigerant collecting passage 22 does not have an excessive refraction point and has a pressure loss. Since the amount is very small, the cooling capacity is kept uniform.

  Since there is no cooling means between the gas jet 19 and the substrate holder 2, the source gas and carrier gas ejected from the gas jet 19 are supplied onto the substrate holder 2 without disturbing the flow. Therefore, since it is possible to prevent the source gases from mixing with each other before reaching the substrate S and generating an additive compound, the utilization efficiency of the source can be improved and the quality of the grown film can be prevented from deteriorating.

  The disc body is composed of a sector block 6 divided into four, and a first spacer block 7, a second spacer block 8, a third spacer block 9, and a fourth spacer block 10 sandwiched between the sector blocks 6. Since the refrigerant collecting passage 22 is constituted by the side surface of the sector block 6 and the end surface grooves formed on the side surfaces of the spacer blocks 7, 8, 9, and 10, the properties of the source gas supplied to the sector block and each spacer block are provided. Can be changed, and various vapor phase growth can be realized. Further, the gas supply unit 5 can be easily manufactured.

  From the sector block 6, carrier gas, from the first spacer block 7 to the first source gas, from the second spacer block 8 to the second source gas, from the third spacer block 9 to the dopant gas, from the fourth spacer block 10 For example, if the first source gas or the second source gas is individually supplied to the substrate holder 2, the first source gas, the second source gas, and the dopant gas are isolated by the carrier gas, and thus reach the substrate S. It is possible to more reliably prevent mixing before performing.

The gas passage 17 is branched downward into a plurality of branch passages 18 from a cooling section surrounded by the upper refrigerant passage 25 and the lower refrigerant passage 26, and a gas outlet 19 is provided at the lower end of each branch passage 18. Since the source gas and the carrier gas can be supplied to the substrate holder 2 in a shower shape, the vapor phase growth on the substrate S is stabilized.
Since the refrigerant jacket 20 is disposed so as to cool the entire side wall 4 of the growth chamber 1, the cooling means can be integrated and the apparatus can be simplified.

As described above, one embodiment of the present invention has been described with reference to FIGS. 1 to 6, but the present invention is not limited to the above embodiment, and for example, raw materials supplied from each sector block and spacer block The arrangement of the gas and the carrier gas may be set so that the first source gas, the second source gas, and the dopant gas are supplied from the sector block and the carrier gas is supplied from the spacer block.
Further, the number of divisions of the sector block may be three or more, and the refrigerant passage may be further multi-staged according to the length of the gas passage instead of the upper and lower stages, and the number of branch passages from the gas passage is other than four. There is no problem.

It is a longitudinal cross-sectional view of the vapor phase growth apparatus which shows one Embodiment of this invention. It is a top view of a gas supply part. It is a bottom view of a gas supply part. It is explanatory drawing of the fan-shaped block of a gas supply part. It is explanatory drawing of the 3rd spacer block of a gas supply part. It is explanatory drawing of the gas channel of a gas supply part, and a gas jet nozzle. It is a longitudinal cross-sectional view of the conventional vapor phase growth apparatus. It is a top view of the conventional vapor phase growth apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Growth chamber 2 Substrate holding stand 3 Heating means 4 Side wall 5 Gas supply part 6 Fan-shaped block 2nd raw material gas supply part 7 1st spacer block 8 2nd spacer block 9 3rd spacer block 10 4th spacer block 11 1st raw material gas Inlet 12 Second source gas inlet 13 Dopant gas inlet 14 First or second source gas inlet 15 Carrier gas inlet 16 Gas distribution space 16a Gas distribution space 17 Gas passage 17a Gas passage 18 Branch passage 18a Branch passage 19 Gas outlet 19a Gas outlet 20 Refrigerant jacket 20a Opening portion 21 Refrigerant supply port 22 Refrigerant collecting passage 22a End 23 First refrigerant outlet 24 Second refrigerant outlet 25 Upper refrigerant passage 26 Lower refrigerant passage S Substrate Y Axis

Claims (5)

A rotatable substrate holder on which a substrate is placed in a growth chamber, a heating means for heating the substrate holder, and a gas that is provided at a position facing the substrate holder and supplies a source gas and a carrier gas toward the substrate A vapor phase growth apparatus comprising a supply unit,
The gas supply unit is a disc body constituting the top plate of the growth chamber, and a gas introduction unit comprising a gas introduction port and a gas distribution space is provided at the upper part of the disc body, and a plurality of gas supply units are provided on the lower surface of the disc body over the entire area. A gas passage that communicates the gas distribution space and the gas jet outlet in parallel with the axis of the substrate holder, and an annular refrigerant jacket is formed on the outer periphery of the disc body, so that the center of the disc body is formed. A refrigerant collecting passage extending in the radial direction and extending to the vicinity of the outer periphery, connecting a refrigerant discharge port to the refrigerant collecting passage at the center of the disc body, and communicating with the refrigerant collecting passage from the refrigerant jacket, A vapor phase growth apparatus characterized by being arranged in a plurality of upper and lower stages and so as to form a cooling section for cooling a gas passage from four sides.   The disc body is composed of a sector block divided into three or more and a spacer block sandwiched between the sector blocks, and the refrigerant collecting passage has both or both of the side surface of the sector block and the side surface of the spacer block. 2. The vapor phase growth apparatus according to claim 1, wherein the vapor phase growth apparatus is constituted by an end face groove formed on one side.   The disk includes a sector block for supplying a carrier gas, a first spacer block for supplying a first source gas, a second spacer block for supplying a second source gas, and a third spacer block for supplying a dopant gas. The vapor phase growth apparatus according to claim 2, wherein the vapor phase growth apparatus is provided.   4. The gas passage according to claim 1, wherein the gas passage is branched into a plurality of branch passages downward from the cooling section, and a gas outlet is provided at a lower end of each branch passage. Vapor growth equipment.   5. The vapor phase growth apparatus according to claim 1, wherein the refrigerant jacket is arranged to cool the entire side wall of the growth chamber.

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