JP2002093727A - Method and device for liquid-phase epitaxial growth - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for liquid-phase epitaxial growth, with which temperature variation on the surface of a semiconductor wafer is eliminated and the thickness of a film grown on the surface can be made uniform. SOLUTION: A semiconductor wafer 2 is placed on the bottom surface 13a of a recessed portion 13 of a wafer-supporting table 3. A dummy member 18, made of single crystals of the same material as that of the semiconductor wafer 2, is placed on the bottom surface 13a of the recessed portion 13, so as to surround the semiconductor wafer 2. Consequently, the semiconductor wafer 2 is placed at a distant from the inner wall of a solution tank 5 and heat from the inner wall of the solution tank 5 will not affect the semiconductor wafer 2. Thus, the thickness of a film grown on the surface of the semiconductor wafer 2 can be distributed uniformly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid phase epitaxial growth method in which a solute of a solution is deposited on a crystal substrate by applying a temperature difference to the solution, and a liquid phase epitaxial growth method capable of improving the uniformity of the film thickness grown on a wafer. And its device.

[0002]

2. Description of the Related Art GaAs is used as a solvent with a low melting point metal such as Ga as a solvent.
When a temperature difference is applied to a solution containing s, GaP as a solute, a raw material crystal is placed on the high-temperature side, and a crystal substrate is placed on the low-temperature side. Material diffusion occurs. Conventionally, there is a liquid phase epitaxial growth method in which a crystal is grown on a crystal substrate by utilizing the diffusion of the crystal material. In this epitaxial growth method, a cooling medium such as a gas is used to make a temperature difference effectively in a solution, and heat may be absorbed on a low temperature side (crystal substrate side).

[0003] In particular, in a horizontal type electric furnace, when a temperature difference is provided in the vertical direction of the solution, it is possible to divide the heater for the solution into upper and lower portions and to set the temperature of the upper and lower heaters separately. ing. However, a sufficient temperature difference cannot be obtained by itself, and it is necessary to absorb heat on the lower side of the solution by forced cooling.

Hereinafter, GaAs, which is a group III-V compound, will be described as an example.

In the liquid phase epitaxial growth method utilizing a temperature difference in a solution, a GaAs substrate is set on a substrate support of a boat, and Ga as a solvent containing a dopant and GaAs polycrystal as a solute (raw material crystal) are used. Are set in the solution reservoir of the boat, and a soaking plate is placed above the GaAs polycrystal. Then, the boat was placed in a furnace core tube in a hydrogen gas atmosphere, and the substrate temperature was set to 600 to 800 ° C.
And the air and N at the bottom of the furnace core tube.
Endotherm is performed with a cooling medium such as gas of ₂ . In this state, when the saturated solution is brought into contact with the upper surface of the GaAs substrate, material diffusion due to the temperature difference of the saturated solution causes G
Crystal growth is performed on the aAs substrate. The reason for installing the heat equalizing plate on the boat is that if the surface of the plate-shaped raw material crystal floating on the liquid surface of the solution is a reflecting surface due to etching treatment before setting to the boat, the heat equalizing plate If not installed on the boat, the solution may cause a variation in how the solution receives the widespread heat from above.

FIGS. 4 (a) and 4 (b) show cross sections of a liquid phase epitaxial growth apparatus for performing epitaxial growth utilizing a temperature difference in a solution by using a horizontal growth furnace provided with a cooling section below a furnace core tube. Show.

As shown in FIG. 4A, a slide boat 41 is used in a liquid phase epitaxial growth method using the liquid phase epitaxial growth apparatus. According to the sliding boat (hereinafter, simply referred to as a boat) 41, a solution reservoir 46 having a solution tank 45 relatively slides on a semiconductor substrate 42 set in a lateral direction on a substrate support 43. As a result, the solution 44 in the solution tank 45 is put on the semiconductor substrate 42 or wiped off. Further, a plate-shaped raw material crystal 52 is charged into the solution 44,
Above the raw material crystal 52, a soaking plate 50 is arranged. As a material of the boat 41, graphite (graphite) subjected to high-purity processing is used.

[0008] The liquid phase epitaxial growth method using the liquid phase epitaxial growth apparatus having the above configuration is performed as follows.

First, the boat 41 in which the semiconductor substrate 42 is set on the substrate support 43 is put into a quartz tube 48 as a furnace core tube. Then, in a hydrogen atmosphere in the quartz tube 48, the temperature of the boat 41 is raised by the heater 49, and the lower part of the quartz tube 48 is cooled by the cooling medium 51. In this state, the solution 44 is maintained for a predetermined time until the solution 44 becomes a saturated solution.

[0010] Thereafter, as shown in FIG.
7, the solution holder 46 is operated to position the solution tank 45 on the semiconductor substrate 42, and the solution 44 is transferred to the semiconductor substrate 42.
Contact surface. Thereby, epitaxial growth is performed, and a crystal grows on the semiconductor substrate 42.

[0011]

By the way, in the above-mentioned liquid phase epitaxial growth method, in order to make the growth film thickness distribution on the surface of the semiconductor substrate 42 uniform, the semiconductor substrate 4 is formed.
The temperature uniformity in the parallel direction (horizontal direction) with respect to the surface of the semiconductor substrate 42 is required while giving a temperature gradient (temperature difference) in the vertical direction to the surface of the semiconductor substrate 42. However, due to the difference between the thermal conductivity of the solution 44 and the thermal conductivity of graphite, which is the material of the boat 41, the amount of heat (heat flow) flowing vertically in each part of the boat 41 is different. And
Since the solution tank 45 uses graphite as a material, the solution tank 45 has a higher thermal conductivity than the solution 44 and is less likely to have a vertical temperature gradient (temperature difference) near the inner wall of the solution tank 45. As a result, as shown in FIG.
On the surface of No. 2, the growth rate is slower in the peripheral part than in the central part due to the thermal conductivity of graphite as the material of the solution tank 45, and the thickness of the peripheral part becomes thinner. That is, there is a problem that the thickness of the grown film varies on the surface of the semiconductor substrate 42.

Further, it is preferable that the heat supplied to the boat 41 from above is absorbed by the cooling medium 51 through the soaking plate 50 / raw material crystal 52 / solution 44 / semiconductor substrate 42 / substrate support 43 in this order. . To this end, it is desirable that the raw material crystal 52 and the heat equalizing plate 50 are evenly and closely adhered in the horizontal direction. However, since the raw material crystal 52 has a plate shape,
As shown in FIG. 6, the raw material crystal 52 and the soaking plate 50 are actually
The solution 44 wraps around between the two. In addition, since the solution 44 in which the solvent 44 is a low melting point metal has viscosity, there are portions where the solution 44 goes around and portions where the solution 44 does not go around. Atmospheric gas exists in a portion where the solution 44 does not flow between the raw material crystal 52 and the soaking plate 50. Such a state differs for each set of the solution 44 in the boat 41. As described above, since the atmosphere gas having a small thermal conductivity partially exists between the raw material crystal 52 and the soaking plate 50, the atmosphere gas in the flow of heat from the soaking plate 50 to the solution 44. Becomes heat resistance, and the heat distribution in the horizontal direction becomes non-uniform. as a result,
The solution 44 is placed between the raw material crystal 52 and the soaking plate 50.
The heat from the upper part is easily transmitted to the part where the gas flows around as compared with the part where the atmospheric gas exists. As a result, the temperature becomes high immediately below the portion where the solution 44 enters between the raw material crystal 52 and the soaking plate 50, and the surface of the semiconductor substrate 42 becomes uneven in temperature. That is, the temperature differs on the surface of the semiconductor substrate 42, and the thickness of the grown film varies.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid phase epitaxial growth method and an apparatus therefor which can eliminate temperature unevenness on the surface of a semiconductor substrate and make the grown film thickness on the surface uniform.

[0014]

In order to achieve the above object, a liquid phase epitaxial growth method according to the present invention is characterized in that a solution tank having an opening at a lower portion is placed on a horizontally set semiconductor substrate in a reactor. By sliding over the solution, the solution in the solution bath is covered or wiped on the semiconductor substrate, and a temperature difference is applied to the solution, and a crystal is grown on the semiconductor substrate using the temperature difference. In the liquid phase epitaxial growth method, the semiconductor substrate is disposed on an opposing portion facing the opening of the solution tank on the bottom surface of the recess accommodating the semiconductor substrate, and on the opposing portion, the semiconductor substrate is surrounded by the semiconductor substrate. It is characterized in that a dummy member made of single crystal or polycrystal of the same material as the semiconductor substrate is arranged.

According to the liquid-phase epitaxial growth method having the above-described structure, since the dummy member is arranged so as to surround the semiconductor substrate, the semiconductor substrate moves away from the inner wall of the solution tank, and the influence of heat supplied from the inner wall of the solution tank is reduced. It does not reach the semiconductor substrate. As a result, a temperature gradient occurs in a direction perpendicular to the surface of the semiconductor substrate, and a temperature in a direction parallel to the surface of the semiconductor substrate becomes uniform. Can be achieved.

If there is no dummy member around the semiconductor substrate, the solution around the semiconductor substrate becomes supersaturated, so that the crystal material diffuses from the inner periphery of the solution tank to the central portion, and the film thickness distribution increases. It causes variation.

In one embodiment of the present invention, the semiconductor substrate and the dummy member have substantially the same thickness.

According to the liquid phase epitaxial growth method of one embodiment of the present invention, it is preferable that the semiconductor substrate and the dummy member have substantially the same thickness in order to eliminate variations in film thickness distribution on the surface of the semiconductor substrate.

In one embodiment of the liquid phase epitaxial growth method according to the present invention, the solution tank having an opening at the bottom slides relatively on a horizontally set semiconductor substrate in a reaction furnace. In the liquid phase epitaxial growth method of covering or wiping the solution in the solution bath onto the semiconductor substrate, applying a temperature difference to the solution, and utilizing the temperature difference to grow a crystal on the semiconductor substrate, Characterized in that raw material crystals to be solutes are submerged in the solution.

According to the liquid phase epitaxial growth method of one embodiment of the present invention, the raw material crystal is placed in the solution in the vertical direction, that is, the raw material crystal is submerged in the solution,
Since the raw material crystal is intentionally positioned in the solution, there is no gap between the raw material crystal and the solution, for example, between the soaking plate and the raw material crystal disposed above the raw material crystal. That is, there is no atmospheric gas between the soaking plate and the raw material crystal. Therefore, the state of contact with the solution in the soaking plate becomes the same in each part, and the flow of heat from the soaking plate to the solution in the horizontal direction becomes uniform. As a result, a temperature gradient occurs in a direction perpendicular to the surface of the semiconductor substrate, and a temperature in a direction parallel to the surface of the semiconductor substrate becomes uniform. Can be achieved.

The liquid phase epitaxial growth method according to one embodiment of the present invention is characterized in that a temperature difference is set so that an upper part of the solution is higher than a lower part of the solution, and the raw material crystal is arranged on a high temperature side of the solution. Features.

According to the liquid phase epitaxial growth method of the embodiment of the present invention, since the source crystal is arranged on the high temperature side of the solution, the source crystal can be effectively diffused.

In one embodiment of the liquid phase epitaxial growth method according to the present invention, the solvent of the solution is a low melting point metal.

According to the liquid phase epitaxial growth method of the embodiment of the present invention, since the solvent of the solution is a metal having a low melting point, crystal growth on the semiconductor substrate can be favorably performed.

In one embodiment of the present invention, the low-melting-point metal is Ga.

According to the liquid phase epitaxial growth method of the embodiment of the present invention, since the low melting point metal is Ga, a III-V compound can be grown on a semiconductor substrate.

In one embodiment of the present invention, the source crystal is GaAs or GaP.
It is characterized by being.

According to the liquid phase epitaxial growth method of one embodiment of the present invention, the raw material crystal is GaAs or G
Since it is aP, a III-V compound can be grown on a semiconductor substrate.

Further, in the liquid phase epitaxial growth apparatus of the present invention, a solution tank having an opening at a lower portion relatively slides on a horizontally set semiconductor substrate in a reaction furnace, thereby forming the solution tank. While covering or wiping the solution on the semiconductor substrate, giving a temperature difference to the solution,
In the liquid phase epitaxial growth apparatus for growing a crystal on the semiconductor substrate by utilizing the temperature difference, the liquid crystal epitaxial growth apparatus further includes an arrangement portion for disposing a dummy member around the semiconductor substrate on a bottom surface of the recess accommodating the semiconductor substrate. Thus, the present invention is characterized in that crystals are grown substantially uniformly on the entire surface of the semiconductor substrate.

According to the liquid phase epitaxial growth apparatus having the above-described configuration, since the arrangement portion for disposing the dummy member is provided around the semiconductor substrate, the semiconductor substrate can be arranged by disposing the dummy member in the arrangement portion. Surrounded by the dummy member, the semiconductor substrate moves away from the inner wall of the solution tank,
The heat supplied from the inner wall of the solution tank does not affect the semiconductor substrate. As a result, a temperature gradient occurs in a direction perpendicular to the surface of the semiconductor substrate, and a temperature in a direction parallel to the surface of the semiconductor substrate becomes uniform. Can be achieved.

The liquid phase epitaxial growth apparatus according to one embodiment of the present invention further comprises a heat equalizing plate disposed on the upper portion of the solution tank and having projections with sharp tips formed regularly on the surface. Features.

According to the liquid-phase epitaxial growth apparatus of the embodiment of the present invention, since the soaking plate is arranged above the solution tank, when the raw material crystal is put into the solution in the solution tank, for example, Are uniformly pressed by the protrusions of the soaking plate, and the raw material crystals are located in the solution. As a result, the solution wraps around between the protrusions, and no gap exists between the soaking plate and the raw material crystal, and the contact state with the solution in the soaking plate can be made the same in each part.

Further, the liquid phase epitaxial growth apparatus according to the invention of one embodiment is characterized in that it has a slanting-shaped floating prevention member disposed in the solution.

According to the liquid phase epitaxial growth apparatus of one embodiment of the present invention, for example, the raw material crystal charged into the solution in the solution tank is sunk under the floating preventing member, and the raw material crystal is positioned in the solution. At this time, since the floating prevention member is in the shape of a snowboard, the solution wraps around, for example, between the raw material crystal and the soaking plate arranged above the raw material crystal,
Since there is no gap between the soaking plate and the raw material crystals, the state of contact with the solution in the soaking plate can be made the same in each part.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a liquid phase epitaxial growth method and apparatus according to the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 (a) is a schematic sectional view of an epitaxial growth apparatus for performing a liquid phase epitaxial growth method according to an embodiment of the present invention, and FIG. 1 (b) is a schematic view of a main part of the liquid phase epitaxial growth apparatus. FIG. In addition,
FIGS. 1A and 1B show a state in which the opening 15 of the solution tank 5 provided in the solution reservoir 6 of the boat 1 is opposed to the recess 13 of the substrate support 3 of the boat 1.

The above liquid phase epitaxial growth apparatus is shown in FIG.
As shown in FIG. 1A, a quartz tube 8 as a reaction furnace, a heater 9 for heating the quartz tube 8, and a slide boat (hereinafter simply referred to as a boat) 1 accommodated in the quartz tube 8 are provided. ing. The boat 1 has a recess 1 for accommodating a semiconductor substrate 2.
The substrate support 3 includes a substrate support 3 provided thereon, and a solution reservoir 6 mounted on the substrate support 3 and sliding relative to the substrate support 3. The solution reservoir 6 serves as the substrate support 3
The solution 4 in the solution tank 5 formed in the solution reservoir 6 is covered or wiped on the semiconductor substrate 2 by relatively sliding on the upper side. A hydrogen gas is supplied into the quartz tube 8 from a supply port (not shown).
Further, the heat absorption in the lower part of the quartz tube 8 is reduced by the cooling medium 11.
It is done in.

Further, as shown in FIG. 1B, the bottom area of the recess 13 of the substrate support 3 is equal to the opening area of the solution tank 5, and the recess facing the opening 15 of the solution tank 5. 1
The semiconductor substrate 2 is disposed on a bottom surface 13a as an opposing portion of the semiconductor substrate 3. When a III-V compound is grown on the semiconductor substrate 2, for example, a low melting point metal such as Ga can be used as a solvent of the solution 4, and GaAs or GaP is used as a raw material crystal 12 as a solute of the solution 4. Can be used. The source crystal 12 is located above the solution 4. Above the source crystal 12, that is, above the solution tank 5, a heat equalizing plate 10 is disposed. Are regularly formed. In addition, the recess 1
On the bottom surface 13 a of the third substrate 3, an arrangement portion 23 for disposing the dummy member 18 around the semiconductor substrate 2 is provided. As shown in FIG. 2, there are four dummy members 18,
It is arranged in the arrangement part 23 so as to surround the semiconductor substrate 2. There is substantially no gap between the dummy members 18, and the dummy members 18 surround the semiconductor substrate 2 substantially continuously.
The dummy member 18 is made of a single crystal of the same material as the semiconductor substrate 2.

In the liquid phase epitaxial growth method using the liquid phase epitaxial growth apparatus having the above structure, the substrate support 3
The semiconductor substrate 2 is set horizontally in the recess 13 of
After filling the solution 4 containing the raw material crystal 12 into the solution tank 5, the soaking plate 10 is arranged on the raw material crystal 12. Then, the boat 1 is placed in the quartz tube 8 in a hydrogen atmosphere, the temperature is raised until a predetermined substrate temperature is reached, and heat is absorbed by the cooling medium 11 below the quartz tube 8. As a result, the temperature of the upper part of the solution 4 becomes higher than that of the lower part thereof,
2 will be located on the hot side of solution 4. After that, the operation reservoir (not shown) is operated to move the solution reservoir 6 to the substrate support 3.
When the saturated solution 4 is brought into contact with the upper surface of the semiconductor substrate 2 by sliding with respect to the solute, the solute is diffused with the temperature difference of the saturated solution 4 and crystals grow on the semiconductor substrate 2. I do. At this time, so as to surround the semiconductor substrate 2,
Since the dummy member 18 is disposed in the recess 13, the solution tank 5
The semiconductor substrate 2 is far away from the inner wall of the substrate, and the heat supplied from the inner wall of the solution tank 5 does not affect the semiconductor substrate 2. As a result, a temperature gradient in the direction perpendicular to the surface of the semiconductor substrate 2 is generated, and the temperature in the direction parallel to the surface of the semiconductor substrate 2 becomes uniform, as shown in FIG. Uniformity of the growth film thickness distribution on the surface can be achieved.

Further, since the placement portion 23 for placing the dummy member 18 around the semiconductor substrate 2 is provided on the bottom surface 13a of the concave portion 13, the placement of the dummy member 18 in the placement portion 23 The semiconductor substrate 2 can be surrounded by the dummy member 18.

In order to eliminate variations in film thickness distribution on the surface of the semiconductor substrate 2, it is preferable that the semiconductor substrate 2 and the dummy member 18 have substantially the same thickness.

Further, since the heat equalizing plate 10 is disposed above the solution tank 5, the raw material crystals 12 in the solution 4 in the solution tank 5 are formed.
Are uniformly pressed by the projections 20 of the soaking plate 10, and the raw material crystal 12 is located in the solution 4. That is, the raw material crystal 12 sinks and is located in the solution 4. As a result, the solution 4 wraps around between the protrusions 20, and no gap exists between the soaking plate 10 and the raw material crystal 12, and the contact state of the soaking plate 10 with the solution 4 becomes the same in each part. Thus, the flow of heat from the heat equalizing plate 10 to the solution 4 becomes uniform in the horizontal direction. As a result, the temperature in the direction parallel to the surface of the semiconductor substrate 2 becomes more uniform while the temperature gradient in the direction perpendicular to the surface of the semiconductor substrate 2 is provided, and the growth film on the surface of the semiconductor substrate 2 is reduced. It can be more uniform.

Further, since the source crystal 12 is disposed above the solution 4, that is, on the high temperature side, the source crystal 12 can be effectively diffused.

In the above embodiment, the heater 9 is not divided into upper and lower parts, but may be divided. Also,
The quartz tube 8 may be vertical or horizontal.

In the above embodiment, the dummy member 1
8 was made of a single crystal of the same material as the semiconductor substrate 2,
It may be made of polycrystal.

The number of the dummy members 18 is four, but may be one, for example. In this case, by arranging an annular dummy member so as to surround the semiconductor substrate 2, the same effect as in the present embodiment can be obtained. In short, the number of the dummy members is not particularly limited.

Further, the dummy member 18 is formed so as to surround the semiconductor substrate 2 without providing a substantial gap between the dummy members 18.
Are arranged substantially continuously, but the dummy members may be arranged continuously so as to surround the semiconductor substrate 2 without providing a gap between the dummy members. Further, a gap may be provided between the dummy members, and the dummy members may be discontinuously arranged around the semiconductor substrate 2.

In the above embodiment, the bottom area of the recess 13 and the opening area of the solution tank 5 are equal, but they need not be equal. For example, the bottom area of the recess is larger than the opening area of the solution tank. It may be made larger.

In the above embodiment, the projections 20 of the heat equalizing plate 10 have a conical shape, but may have a triangular or quadrangular pyramid shape, for example.

FIG. 3 is a sectional view of a main part of a liquid phase epitaxial growth apparatus according to another embodiment of the present invention. The same members as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. According to this liquid phase epitaxial growth apparatus, as shown in FIG. 3, instead of using the soaking plate 10 (see FIG. 1), a soaking plate 30 having a smooth surface on the side of the raw material crystal 12 is used. The floating prevention member 39 in the shape of a mushroom is disposed in the solution 4. Then, the floating prevention member 39
Underneath the raw material crystal 12,
Is located in solution 4. At this time, since the floating prevention member 39 is in the shape of a saw, the solution 4 wraps between the heat equalizing plate 30 and the raw material crystal 12, so that no gap exists between the heat equalizing plate 30 and the raw material crystal 12. And soaking plate 10
Can be made the same in each part in the contact state with the solution 4, and the same effect as in the present embodiment can be obtained.

[0051]

As described above, according to the liquid phase epitaxial growth method of the present invention, since the dummy member is arranged so as to surround the semiconductor substrate, the semiconductor substrate moves away from the inner wall of the solution tank, and the semiconductor substrate extends in a direction perpendicular to the surface of the semiconductor substrate. A temperature gradient is generated, and the temperature in the direction parallel to the surface of the semiconductor substrate becomes uniform, so that the growth film thickness distribution on the surface of the semiconductor substrate can be made uniform.

In the liquid phase epitaxial growth method according to one embodiment of the present invention, it is preferable that the semiconductor substrate and the dummy member have substantially the same thickness in order to eliminate variations in film thickness distribution on the surface of the semiconductor substrate.

In the liquid phase epitaxial growth method according to one embodiment of the present invention, the raw material crystal is immersed in the solution, and the raw material crystal is intentionally positioned in the solution. There is no gap between the crystal and the contact state with the solution in the soaking plate is the same in each part,
The flow of heat from the soaking plate to the solution becomes uniform in the horizontal direction. As a result, a temperature gradient occurs in a direction perpendicular to the surface of the semiconductor substrate, and a temperature in a direction parallel to the surface of the semiconductor substrate becomes uniform. Can be achieved.

In the liquid phase epitaxial growth method according to one embodiment of the present invention, the source crystals are arranged on the high temperature side of the solution, so that the source crystals can be effectively diffused.

According to the liquid phase epitaxial growth method of one embodiment of the present invention, since the solvent of the solution is a low melting point metal, it is possible to favorably grow a crystal on a semiconductor substrate.

According to the liquid phase epitaxial growth method of one embodiment of the present invention, since the low melting point metal is Ga, a III-V compound can be grown on a semiconductor substrate.

According to the liquid phase epitaxial growth method of one embodiment of the present invention, the raw material crystal is GaAs or GaP.
Therefore, the III-V compound can be grown on the semiconductor substrate.

Further, since the liquid phase epitaxial growth apparatus of the present invention has an arrangement portion for disposing a dummy member around the semiconductor substrate, by disposing the dummy member at the arrangement portion, A temperature gradient in the direction perpendicular to the surface is generated, and the temperature in the direction parallel to the surface of the semiconductor substrate becomes uniform, so that the growth thickness distribution on the surface of the semiconductor substrate can be made uniform.

In the liquid phase epitaxial growth apparatus according to one embodiment of the present invention, since the above-mentioned soaking plate is arranged above the solution tank, when a raw material crystal is put into the solution in the solution tank, for example,
The raw material crystals are evenly pressed by the protrusions of the heat equalizing plate, and the raw material crystals are located in the solution, so that the contact state of the heat equalizing plate with the solution can be the same in each part.

In the liquid-phase epitaxial growth apparatus according to one embodiment of the present invention, since the slant-shaped floating prevention member is disposed in the solution, the liquid crystal epitaxial growth apparatus is disposed between the raw material crystal and the soaking plate, for example, above the raw material crystal. The solution wraps around the soaking plate and there is no gap between the soaking plate and the raw material crystals, and the contact state of the soaking plate with the solution can be made the same in each part.

[Brief description of the drawings]

FIG. 1A is a schematic sectional view of a liquid phase epitaxial growth apparatus according to an embodiment of the present invention, and FIG. 1B is an enlarged sectional view of a main part of the liquid phase epitaxial growth apparatus.

FIG. 2 is a top view of a growth area of the liquid phase epitaxial growth apparatus and a graph showing a thickness distribution of a semiconductor substrate in the growth area.

FIG. 3 is an enlarged sectional view of a main part of a liquid phase epitaxial growth apparatus according to another embodiment of the present invention.

FIG. 4 is a sectional view of a conventional liquid phase epitaxial growth apparatus.

FIG. 5 is a schematic sectional view of the conventional liquid phase epitaxial growth apparatus, a top view of a growth area of the conventional liquid phase epitaxial growth apparatus, and a graph showing a thickness distribution of the semiconductor substrate in the growth area.

FIG. 6 is an enlarged sectional view of a main part of the conventional liquid phase epitaxial growth apparatus.

[Explanation of symbols]

 Reference Signs List 2 semiconductor substrate 5 solution tank 8 quartz tube 13 recess 13a bottom of recess 15 opening 18 dummy member

Claims (10)

[Claims] 1. A solution tank having an opening at a lower portion relatively slides on a semiconductor substrate set horizontally in a reaction furnace, so that the solution in the solution tank is covered on the semiconductor substrate. In addition to wiping, a temperature difference is applied to the solution, and a liquid phase epitaxial growth method is used to grow a crystal on the semiconductor substrate by using the temperature difference. On the opposing portion facing the opening, the semiconductor substrate is arranged, and on the opposing portion, a dummy member made of a single crystal or polycrystal of the same material as the semiconductor substrate is arranged so as to surround the semiconductor substrate. Characteristic liquid phase epitaxial growth method. 2. The liquid phase epitaxial growth method according to claim 1, wherein said semiconductor substrate and said dummy member have substantially the same thickness. 3. A solution tank having an opening at a lower portion relatively slides on a semiconductor substrate set horizontally in a reaction furnace, so that the solution in the solution tank is put on the semiconductor substrate. In the liquid phase epitaxial growth method of wiping and applying a temperature difference to the solution and using the temperature difference to grow a crystal on the semiconductor substrate, a raw material crystal serving as a solute of the solution is submerged in the solution. And a liquid phase epitaxial growth method. 4. The liquid phase epitaxial growth method according to claim 1, wherein a temperature difference is set so that an upper part of the solution is higher than a lower part of the solution, and A liquid phase epitaxial growth method comprising arranging raw material crystals. 5. The liquid phase epitaxial growth method according to claim 1, wherein the solvent of the solution is a low melting point metal. 6. The liquid phase epitaxial growth method according to claim 5, wherein said low melting point metal is Ga. 7. The liquid phase epitaxial growth method according to claim 1, wherein the material crystal is GaAs or GaP. 8. A solution tank having an opening at a lower portion relatively slides on a semiconductor substrate set horizontally in a reaction furnace, so that the solution in the solution tank is covered on the semiconductor substrate. In the liquid phase epitaxial growth apparatus for wiping and applying a temperature difference to the solution and utilizing the temperature difference to grow a crystal on the semiconductor substrate, the semiconductor substrate is provided at the bottom surface of the recess accommodating the semiconductor substrate. A liquid phase epitaxial growth apparatus, comprising: an arrangement portion for arranging a dummy member around the semiconductor substrate, wherein crystals are grown substantially uniformly over the entire surface of the semiconductor substrate. 9. The liquid phase epitaxial growth apparatus according to claim 8, further comprising: a heat equalizing plate disposed on the upper portion of the solution tank and having projections with sharp tips formed regularly on the surface. Characteristic liquid phase epitaxial growth equipment. 10. The liquid-phase epitaxial growth apparatus according to claim 9, further comprising a slanting-shaped floating prevention member disposed in the solution.