JP2003160315A - Method for synthesizing polycrystalline semiconductor compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for synthesizing a III-V group polycrystalline semiconductor compound by which a reusable life of a boat for synthesis can be improved. <P>SOLUTION: The method for synthesizing the III-V group polycrystalline semiconductor compound is said that the boat 4 with a slit 51 packed with a III group raw material is placed at one end side in a sealed tube and meanwhile a V group raw material is placed at another end side and then the sealed tube is heated in this condition. The boat 4 is comprised of belt-like notched parts 52 lengthened from the open peripheries at the both open ends of the cylindrical wall of the boat body 50 to the slit ends direction and cover parts 60 screwed at the both open ends of the boat body holding the heat-resistant film disks 70 with projection parts 71 fitted to the belt-like notched parts. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to GaP, etc. III-V
The present invention relates to a method for synthesizing a group-compound semiconductor polycrystal, and in particular, it can prevent a phenomenon in which a group III raw material filled in a synthesis boat leaks to a screwing portion between a boat body and a lid material, and a lid material is used after the synthesis is completed. The synthetic boat is prevented from being chipped or damaged when it is removed from the boat body, and its reuse life can be improved. II
The present invention relates to a method for synthesizing a group IV compound semiconductor polycrystal.

[0002]

2. Description of the Related Art III-V group compound semiconductors such as GaP are
Conventionally, it has been used as a material for optical devices such as laser diodes and light emitting diodes and high-speed devices such as HEMTs.

In such III-V group compound semiconductors, it is difficult to directly react a III group material such as Ga and a V group material such as P to grow a single crystal.
Group III compound semiconductor polycrystals were first synthesized and then III-
Using the VEC compound semiconductor polycrystal by the LEC method etc. III
A method of growing a group V compound semiconductor single crystal has been adopted.

The III-V group compound semiconductor polycrystal is synthesized by loading a sealed tube 1 made of quartz or the like filled with each raw material into a horizontal high-pressure furnace 2 as shown in FIG. Has been.

That is, as shown in FIG.
The group raw material 3 is the boat 4 for synthesis provided with the slit 51.
(See FIG. 3) and the entire boat 4 is housed in an inner tube 5 made of quartz or the like and arranged on one end side of the sealed tube 1. The V group raw material 6 such as P is heat shielded. It is arranged on the other end side of the sealed tube 1 via a plate 7. The sealed tube 1 filled with the raw material and the like is then evacuated and completely sealed.

Next, the sealed tube 1 is evacuated and sealed.
Is carried into a horizontal high-pressure furnace 2 constituted by a high-pressure vessel having a high-frequency coil 8 in the center and sandwiching the high-frequency coil 8 in the center and having resistance heaters 9 on both sides thereof.

Then, the whole sealed tube 1 is heated in the horizontal high-pressure furnace 2, the group III raw material 3 in the synthesis boat 4 is locally heated to a higher temperature by the high-frequency coil 8, and the group V raw material 6 is also heated. The generated source gas is the heat shield plate 7
Is introduced into the inner pipe 5 through the introduction pipe 10 attached to the inner pipe 5 and reacts with the group III raw material 3 and the sealed pipe 1 is connected with the arrow α.
III-V group compound semiconductor polycrystal by moving the inside of the horizontal high-pressure furnace 2 or fixing the sealed tube 1 and moving the horizontal high-pressure furnace 2 in the opposite direction (that is, relatively moving the high temperature part). Is synthesized.

[0008]

By the way, as shown in FIGS. 3 and 4, the synthesizing boat 4 used in the method for synthesizing a III-V group compound semiconductor polycrystal has a linear slit 51 in the upper longitudinal direction. Cylindrical boat body 50 opened
And a lid member 60 screwed to both open ends of the boat body 50.
The main part is constituted by and, and only the slit 51 is opened so that the raw material gas can enter and exit the boat 4.

Since the lid member 60 and the boat body 50 are screwed to each other via the screw portions provided on the boat body 50, the screw portion of the lid member 60 and the screw portion of the boat body 50 are not damaged. If they were present or loosened, gaps were created at these screwed parts, and the group III raw material filled in the synthesis boat 4 could leak to the screwed parts.

When the III-V compound semiconductor polycrystal is synthesized in this state, a part of the group III raw material leaked to the screwing portion reacts with the group V raw material gas at this portion, and III
A case where a group V compound semiconductor polycrystal may be generated, and the cover material 60 is removed from the boat body 50 at the time when the synthesis of the compound semiconductor polycrystal is completed due to the crystal formed in the screwing portion. In addition, there is a problem that the lid member 60 is difficult to come off.

When the lid member 60 is forcibly removed from the boat body 50, the synthesis boat 4 is apt to be chipped or damaged, which hinders the reuse of the synthesis boat 4 and III-V.
There is a problem of increasing the manufacturing cost of the group compound semiconductor polycrystal.

Further, when the group III raw material remains in the unreacted state in the vicinity of the lid member 60, the III-V compound semiconductor polycrystal synthesized through the unreacted group III raw material and the lid member 60 adhere to each other. Similarly to the above, if the lid member 60 is forcibly removed, the synthesis boat 4 is likely to be chipped or damaged, and the reuse of the synthesis boat 4 is hindered and the III-V group compound semiconductor is prevented. There was a problem of increasing the manufacturing cost of the polycrystal.

The present invention has been made by paying attention to such a problem, and the problem is that the group III raw material filled in the boat leaks to the screwed portion between the boat body and the lid. A method for synthesizing a group III-V compound semiconductor polycrystal, which can prevent the phenomenon, and also prevent the synthetic boat from being chipped or damaged when the lid material is removed from the boat body after the synthesis is completed to improve the reuse life thereof. To do.

[0014]

That is, the invention according to claim 1 is to provide a cylindrical boat body having a linear slit formed in the upper longitudinal direction and a lid screwed to both open ends of the boat body. In the boat, the main part of which is made of timber and
A group V raw material is filled, and the boat is placed on one end side in the sealed tube, while a group V raw material is placed on the other end side in the sealed tube to heat the entire sealed tube and locally feed the group III raw material in the boat. Compound semiconductor for synthesizing a group III-V compound semiconductor polycrystal while heating the gas to a higher temperature by reacting the source gas generated from the group V source with the group III source and gradually moving the high temperature part relatively Assuming a method of synthesizing a polycrystal, strip-shaped notches extending from the open edge toward the slit end are provided on both open end side cylinder wall surfaces of the boat body, respectively, and are slightly larger than the open surface of the boat body and outside thereof. With a circular or polygonal heat-resistant film body provided with a protruding piece fitted to the above-mentioned band-shaped cutout part at a part of the peripheral edge, a lid member is screwed to both open ends of the boat main body, respectively. Then the above boat is constructed The invention according to claim 2 is based on the method for synthesizing a compound semiconductor polycrystal according to claim 1, wherein the boat body and the lid are made of graphite, and the heat resistance is high. The characteristic film body is composed of a carbon film.

According to the method for synthesizing a compound semiconductor polycrystal according to the present invention, the strip shape extending from the open edges toward the slit ends on both open end side cylinder wall surfaces of the boat body. A circular or polygonal heat-resistant film body is provided, which is provided with notches, is slightly larger than the open surface of the boat body, and is provided with a protruding piece that fits into the above-mentioned notch on a part of its outer peripheral edge. Since the boat is constructed by screwing the lid material to both open ends of the boat body in a state of being interposed in the boat, the screw portion of the lid material and the screw portion of the boat body may be chipped or loosened. Even if a gap is created at these screwed parts, the heat-resistant film body interposed between the lid material and the open end of the boat body causes the group III raw material filled in the boat to leak to the screwed parts. Without doing Even when the group III raw material remains in the unreacted state in the vicinity of the lid material, the III-V compound semiconductor polycrystal synthesized by the action of the heat resistant film body and the lid material do not adhere to each other. .

Therefore, the lid member can be easily removed from the boat body when the synthesis of the compound semiconductor polycrystal is completed, and the reuse of the boat is not hindered.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings.

That is, the method of synthesizing the compound semiconductor polycrystal according to this embodiment is substantially the same as the conventional synthesis method except that the boat for filling the group III raw material has a structure as shown in FIG. Is.

First, in the boat 4, as shown in FIG. 1, linear slits 51 are formed in the upper longitudinal direction of the cylindrical wall surface, and the cylindrical wall open edge portions are wider than the slits 51 on both open end side cylindrical wall surfaces. And a cylindrical boat main body 50 made of graphite, which is provided with strip notches 52 connected to the ends of the slits 51, and a lid made of graphite screwed to both open ends of the cylindrical boat main body 50. 60, which is interposed between the cylindrical boat main body 50 and the lid member 60, has a diameter slightly larger than the inner diameter of the cylindrical boat main body 50, and is fitted to the strip notch 52 at a part of the outer peripheral edge thereof. Projected piece 71
The main part of the heat-resistant film 70 having a circular shape is
The group raw material 3 is filled.

The boat 4 filled with the group III raw material 3 is housed in a quartz inner tube 5 and, as shown in FIG. 2, each quartz inner tube 5 and one end of the quartz sealed tube (outer tube) 1 In addition, the group V raw material 6 is arranged on the other end side of the quartz sealed tube 1, and the heat shielding plate 7 made of opaque quartz is arranged substantially in the center of the quartz sealed tube 1. The heat shield plate 7 has an introduction pipe 10
The quartz tube 5 is communicated with the space in which the group V raw material 6 is arranged through the introduction tube 10.

Next, the opening of the quartz sealed tube (outer tube) 1 containing the quartz inner tube 5, the heat shield plate 7, the group V raw material 6 and the like is closed,
After vacuuming, the seal is cut off.

Next, the horizontal high-pressure furnace 2 constituted by a high-pressure vessel having a high-frequency coil 8 in the center and having resistance heaters 9 on both sides of the high-frequency coil 8 sandwiched in the center is sealed and sealed. After the quartz sealing tube (outer tube) 1 is carried in and the high-pressure vessel of the horizontal high-pressure furnace 2 is filled with an inert gas such as nitrogen to set the inside of the high-pressure furnace to a high pressure state, the resistance heater 9 is operated to seal the quartz. The entire tube (outer tube) 1 is heated and the high frequency coil 8
To locally heat the group III raw material 3 in the boat 4 to a higher temperature.

Then, the raw material gas from the group V raw material 6 introduced into the quartz inner tube 5 through the introduction tube 10 attached to the heat shield plate 7 is reacted with the group III raw material 3 in the boat 4, Further, the quartz sealed tube (outer tube) 1 or the horizontal high-pressure furnace 2 is moved (that is, the high temperature portion is relatively moved), and the above reactions are sequentially advanced in the boat 4 to synthesize a III-V group compound semiconductor polycrystal. To do.

According to the synthesis method of this embodiment,
Strip-shaped notches 52 that are wider than the slits 51 and extend from the cylinder wall open edge portion and are connected to the ends of the slits 51 are provided on both open-end-side cylinder wall surfaces of the boat body 50, respectively.
A circular heat-resistant film body 70 having a diameter slightly larger than the inner diameter of the boat main body 50 and provided with a protruding piece 71 fitted to the band-shaped notch 52 on a part of its outer peripheral edge is interposed. Lid 6 on both open ends of the boat body 50
Since 0 is screwed to each of them, even if the screw portion of the lid member 60 or the screw portion of the boat main body 50 is chipped or loosened to form a gap in these screwed portions, The heat-resistant film body 70 interposed between the open ends of the boat body 50 prevents the group III raw material 3 filled in the boat 4 from leaking to the screwing portion, and further, in the vicinity of the lid member 60. Even when the group III raw material 3 remains in the unreacted state, the III-V group compound semiconductor polycrystal synthesized by the action of the heat resistant film body 70 and the lid member 60 do not adhere to each other.

Therefore, when the lid member 60 is removed from the boat body 50 at the time when the synthesis of the compound semiconductor polycrystal is completed, the lid member 60 does not easily come off unlike the conventional case.
It has the advantage that reuse of the boat 4 is not hindered.

The width dimensions of the band-shaped notches 52 provided on the cylinder wall surfaces on both open end sides of the boat body 50 may be the same as or narrower than the slit 51.
The strip notch 52 does not necessarily have to be connected to the end of the slit 51.

Examples of the material of the heat resistant film body 70 include carbon film and pyrolytic boron nitride (p-BN) film. Further, the diameter of the heat-resistant film body 70 may be slightly larger than the inner diameter of the boat body 50. By interposing the heat-resistant film body 70 between the lid member 60 and the open end of the boat body 50, the heat-resistant film body 70 is provided inside the boat 4. The size is arbitrary as long as the filled group III raw material 3 does not leak to the screwing part. Note that the shape of the heat-resistant film body 70 is not limited to a circular shape as long as the leakage of the group III raw material 3 filled in the boat 4 to the screwed portion is prevented. It may be a polygonal shape such as a regular octagon slightly larger than the surface. Further, regarding the width dimension of the projection piece 71 provided on the outer peripheral edge of the heat resistant film body 70, the projection piece 7 is
It suffices that 1 is fitted in the band-shaped notch 52 of the boat body 50 and held in the boat 4, and these dimensions are also arbitrary.

[0028]

EXAMPLES Examples of the present invention will be specifically described below.

First, the diameter is 42 mm and the thickness is 0.4 m, which is slightly larger than the inner diameter of the graphite boat main body 50 shown in FIG.
The synthetic boat 4 was assembled by screwing the lid members 60 to both open ends of the graphite boat main body 50 with the carbon film heat-resistant film body 70 of m interposed therebetween.

As shown in FIG. 2, the boat 4 has an outer diameter of 48 mm, an inner diameter of 40 mm, and a length of 745 mm, and gallium (G
a) 2000 g is divided into two equal parts and filled.

Next, the graphite boat 4 filled with the group III raw material 3 is housed in the inner quartz tube 5, and as shown in FIG. 1, each inner quartz tube 5 is arranged at one end of the inner quartz tube 1. Along with the other end of the quartz sealed tube 1, red phosphorus (P) 920 which is a group V raw material 6 is also provided.
g was placed. An opaque heat shield plate 7 made of opaque quartz is arranged in the quartz sealed tube 1 to which an introduction tube 10 for introducing the raw material gas of the group V raw material 6 into the inner quartz tube 5 is attached.

Next, the mouth of the quartz sealed tube 1 containing the quartz inner tube 5, the heat shield plate 7, the group V raw material 6 and the like is closed, and the inside is filled with 10
After vacuuming to ^-6 Torr order, seal off.

Next, the horizontal high-pressure furnace 2 constituted by a high-pressure vessel having a high-frequency coil 8 in the center and sandwiching the high-frequency coil 8 in the center and having resistance heaters 9 on both sides of the high-frequency coil 8 is sealed off. The quartz sealed tube 1 is carried in, and the high-pressure container of the horizontal high-pressure furnace 2 is filled with nitrogen gas so that the high-pressure furnace is in a high-pressure state (40
(Kg / cm ² ), and then the resistance heater 9 is actuated to heat the entire quartz sealed tube 1 to produce red phosphorus (P) which is the group V raw material 6.
To 300 ° C to 700 ° C, and II in the boat 4
Gallium (Ga), which is Group I raw material 3, is added at 500 ° C to 600 ° C.
The temperature is maintained in the range of 0 ° C., and the high frequency coil 8 is operated to maintain the inside of the boat 4 at a temperature around 1470 ° C. which is the melting point of GaP.

Then, the raw material gas from the V group raw material 6 introduced into the quartz inner tube 5 through the introduction tube 10 attached to the heat shield plate 7 is reacted with the III group raw material 3 in the boat 4. In addition, the quartz sealed tube 1 is moved in the horizontal high-pressure furnace 2 in the direction of the arrow α (that is, the high temperature portion is relatively moved), and the reaction is sequentially advanced in the boat 4 to be integrated III-V. A group compound semiconductor (GaP) polycrystal was synthesized.

On the other hand, as a comparative example, a conventional boat having no carbon film heat-resistant film 70 interposed was also assembled, and the synthesis conditions were the same as in the example III-
A Group V compound semiconductor (GaP) polycrystal was synthesized.

Then, the III-V group compound semiconductor (GaP) polycrystals according to the example and the comparative example were repeatedly synthesized,
The leakage state of gallium (Ga), which is a group III raw material, the adhesion state of the synthesized polycrystal and the lid member 60, and the reuse life (durability) of the graphite boat 4 were compared. The results are shown in Table 1 below.

In Table 1, "Raw material leak rate (%)" is the ratio of the number of leaked raw materials to the number of repeated synthesis, and "Adhesion rate with lid (%)" is the above synthetic number. III-V compound semiconductors (Ga
P) It is the ratio of the number of polycrystals and the lid member 60 bonded. In addition, the “damage rate of graphite boat (%)” is the ratio of the number of damaged boats when taking out the synthesized III-V compound semiconductor (GaP) polycrystal with respect to the number of synthesis, “average number of uses (times)” "Is the average number of times that one graphite boat was repeatedly used for synthesis.

[0038]

[Table 1] As is clear from the numerical values shown in Table 1, leakage of gallium (Ga), which is a group III raw material, synthesized III-V group compound semiconductor (GaP) polycrystal and lid 6 in the examples.
It is confirmed that there is almost no adhesion with 0, and the incidence of adhesion is significantly reduced.

The breakage rate of the graphite boat in the example was 0.7%, which was greatly reduced from 18.2% in the comparative example, and the average number of uses of the graphite boat in the example was 6.5 times. It is confirmed that it is remarkably improved as compared with 2.4 times of the comparative example.

[0040]

According to the method for synthesizing a compound semiconductor polycrystal according to the first and second aspects of the present invention, a strip-shaped notch extending from the open edge toward the slit end is formed on both open end side cylinder wall surfaces of the boat body. And a circular or polygonal heat-resistant film body that is slightly larger than the open surface of the boat body and has a projection piece fitted to the above-mentioned band-shaped cutout portion at a part of the outer peripheral edge thereof. In this state, the boat is constructed by screwing the lids to the open ends of the boat, respectively.Therefore, the screw of the lid and the screw of the boat may be chipped or loosened. Even if there is a gap in the screwed part, the group III raw material filled in the boat leaks to the screwed part due to the action of the heat-resistant film body interposed between the lid material and the open end of the boat body. And the above lid material Even if the group III material near has remained at an unreacted state, the heat-resistant group III-V were synthesized by the action of the film body compound semiconductor polycrystalline and the lid member and is not also result in the adhesive.

Therefore, since the lid material can be easily removed from the boat body when the synthesis of the compound semiconductor polycrystal is completed, it is possible to prevent the boat from being chipped or damaged, which leads to the reuse life of the boat. It has the effect of making a great improvement.

[Brief description of drawings]

FIG. 1 is a partial exploded perspective view of a boat applied to a method for synthesizing a compound semiconductor polycrystal according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a method for synthesizing a III-V compound semiconductor polycrystal.

FIG. 3 is a schematic perspective view of a boat applied to a method for synthesizing a III-V compound semiconductor polycrystal according to a conventional example.

FIG. 4 is a partial exploded perspective view of a boat applied to a method for synthesizing a III-V compound semiconductor polycrystal according to a conventional example.

[Explanation of symbols]

4 boats 50 boat body 51 slits 52 band notch 60 lid material 70 Heat-resistant film body 71 projection piece

Claims (2)

[Claims] Claim: What is claimed is: 1. In a boat, the main part of which is composed of a cylindrical boat main body having a linear slit formed in the upper longitudinal direction and a lid member screwed to both open ends of the boat main body.
The group I raw material is filled, and the boat is placed on one end side in the sealed tube, while the group V raw material is placed on the other end side in the sealed tube to heat the entire sealed tube and remove the group III raw material in the boat. A compound for synthesizing a group III-V compound semiconductor polycrystal while locally heating the gas to a higher temperature to react the source gas generated from the group V source material with the group III source material and gradually moving the high temperature part relatively In the method for synthesizing semiconductor polycrystals, strip-shaped notches extending from the open edge toward the slit end are provided on both open end side cylinder wall surfaces of the boat main body, and the outer peripheral edge is slightly larger than the open surface of the boat main body. With a circular or polygonal heat-resistant film body provided with a protruding piece fitted to the above-mentioned band-shaped notch in a part thereof, a lid member is screwed to both open ends of the boat body, respectively. The above boat is constructed Compounds method of synthesizing a semiconductor polycrystal, characterized in that it is. 2. The method for synthesizing a compound semiconductor polycrystal according to claim 1, wherein the boat main body and the lid are made of graphite, and the heat resistant film is made of a carbon film.