JP2000086398A - P type gaas single crystal and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a single crystal having a low average dislocation density in good yield by including specific amounts of Si and a dopant which is a GaAs single crystal manifesting the p-type. SOLUTION: The content of p-type dopant (e.g. Zn) based on Si is within the range of 1.5-200 expressed in terms of atomic ratio. The average dislocation density of the resultant p-type GaAs single crystal is <=500 cm-2. For production, a dopant manifesting the p-type is filled in a p-type GaAs single crystal in a growth container so as to provide >=1 and <=1,000 ratio expressed in terms of atomic ratio to the Si and usually contain 1×1017 to 5×1019 cm-3 atoms Si and 1×1018 to 1×1020 cm-3 atoms p-type dopant to produce the single crystal according to a transverse type boat growth method or a vertical type boat method. A GaAs seed crystal 3 is filled in a crucible 1 having 3 inches diameter and made of a pyrolytic boron nitride and a GaAs polycrystal 4 and B2O3 5 are then filled thereon. Zn 6 and Si 7 are then added thereto and the resultant. mixture is subsequently vacuum sealed in a quartz ampul 2, heated with a heater 8 and annealed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a low dislocation p-type Ga
The present invention relates to an As single crystal and a method for producing the same.

[0002]

2. Description of the Related Art A p-type GaAs single crystal is cut out and widely used as a substrate for epitaxial growth for manufacturing a compound semiconductor laser, a light emitting diode (LED) and the like.

As described above, compound semiconductor lasers and LEDs
Conventionally, a p-type GaAs single crystal widely used for such purposes includes a horizontal Bridgman method (HB method), a horizontal temperature gradient solidification method (GF method), a liquid sealing pulling method (LEC method), and a vertical Bridgman method ( VB method), vertical temperature gradient solidification method (VG
It is known that it is manufactured by various methods such as F method).

Of these, compound semiconductor lasers are required to have high luminous efficiency and long life, so that p-type Ga with lower dislocations is used.
There has been a need for As single crystals. For this reason, the horizontal Bridgman method (HB
Method), horizontal temperature gradient solidification method (GF method) or vertical Bridgman method (VB method), vertical temperature gradient solidification method (VGF method)
And other techniques have been used.

[0005]

However, according to any of the above methods, the average dislocation density is approximately 1000 cm ^-2 or more, and p-type GaAs having an average dislocation density of 500 cm ^-2 or less.
It was difficult to obtain a single crystal with good yield.

On the other hand, it is known that doping S and Si into the crystal is effective for reducing dislocations. In this case, however, there is a problem that only an n-type GaAs single crystal can be obtained. .

[0007] Further, an example of means for solving such a problem and
GaAs in the horizontal Bridgman method (HB method)
Double doping of Zn and S in the crystal
No. 57079. However, with this method
Also has an average dislocation density of 1000cm ^-2The following p-type GaAs single bond
Crystals are obtained, but the average dislocation density is 500 cm^-2Is less than
It has been difficult to produce a p-type GaAs single crystal.

Furthermore, it has been reported that In, which is a neutral impurity, is effective in reducing dislocations in GaAs crystals (Pro
c. 12th Intern. Symp. on GaAs and Related Compound
s, London-Bristol, 1986, p7-2). Such reports include Z
n concentration 1.5 × 10 ¹⁹ cm ⁻³ , In concentration 4.0 × 10
It is shown that a 2-inch GaAs substrate doped with ¹⁹ cm ^-3 becomes a dislocation-free substrate.

However, since In has a small segregation coefficient of 0.1, in order to dope a high concentration of In into the crystal as described above, G which contains a large amount of In in advance is used.
It was necessary to produce a single crystal from the aAs melt. However, when a crystal is manufactured under these conditions, cell growth due to compositional supercooling starts in the course of solidification of the crystal, resulting in a problem that productivity is significantly deteriorated.

Therefore, an object of the present invention is to provide a p-type GaAs single crystal that solves the conventional problems and a method for manufacturing the same.

It is another object of the present invention to provide an average dislocation density of 5
An object of the present invention is to provide a p-type GaAs single crystal having a size of not more than 00 cm ^-2 and a method for producing the same.

[0012]

The p-type GaAs single crystal which achieves the above-mentioned object of the present invention comprises Si as a dopant.
And a dopant showing a p-type in the GaAs single crystal,
1.5 to 2 as an atomic ratio of the p-type dopant to
It is characterized by being included in the range of 00, especially 2 to 100.

[0013] In another embodiment, B and / or S is further contained as a dopant in an atomic ratio to Si in the range of 0.001 to 1000.
By containing an atomic concentration of 1 × 10 ¹⁷ to 1 × 10 ²⁰ cm ⁻³ , a lower dislocation p-type GaAs single crystal can be obtained.

In one embodiment, the carrier concentration is 1 ×
It is characterized by being 10 ^{18 to} 5 × 10 ¹⁹ cm ⁻³ .

In the p-type GaAs single crystal having such characteristics, the average dislocation density can be set to 500 cm ⁻² or less.

In the above, at least a part of Si can be replaced with Se and / or Te. There is no particular limitation on the doping method for any of the dopants, and the doping source may be, for example, any of metals, compounds, oxides, impurities in a raw material polycrystal or a container, and solid doping. ,
It may be liquid or gas.

Further, in producing the p-type GaAs single crystal having the above characteristics, Si and a p-type GaAs single-crystal dopant exhibiting a p-type dopant in the p-type GaAs single crystal are expressed by an atomic ratio to Si. Usually, Si is 1 × 10 ^{17 to} 5 × 10 ¹⁹ cm ⁻³ atoms, and the dopant showing the p-type is 1 × 10 ¹⁸ to 1 × 10 so that it is larger than 1 and 1000 or less, especially 1.1 to 500. Either the horizontal boat growth method or the vertical boat growth method can be used by filling the growth container with a dopant so as to have a range of ²⁰ cm ⁻³ atoms.

Further features and effects of the present invention will become apparent from the following description of the embodiments of the present invention.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. As described above, the grown p-type GaAs single crystal is cut out and used as an epitaxial semiconductor substrate. Therefore, in the description of the present invention, the meaning of the term of the p-type GaAs single crystal and the protection of the invention will be described. The range includes the grown p-type GaAs single crystal and the cut-out p-type GaAs single-crystal semiconductor substrate, unless otherwise specified.

The inventor of the present invention has intensively studied to solve the problems existing in the prior art described above. As a result, GaAs
Double doping of the crystal with Si and a p-type dopant in the GaAs single crystal, in particular, as a specific ratio, that is, as an atomic ratio of the p-type dopant to Si:
5 to 200, especially 2 to 100, preferably 2 to 5
It has been found that, by being present together in the range of 0, Si effectively suppresses the transfer of dislocation, and a p-type GaAs single crystal with low dislocation can be obtained. Normally, by manufacturing the silicon and the concentration of the p-type dopant such as the impurity to be doped in a predetermined range, it is possible to obtain a p-type GaAs single crystal having a preferable average dislocation density.

In one embodiment according to the present invention, Si is contained as an impurity in an amount of 1 × 10 ^{17 to} 5 × 10 ¹⁹ cm ⁻³ , especially 1 × 10 ¹⁷ to 1 × 10 ¹⁹ cm ⁻³ , 1.1 × 10 ¹⁷ to 1 × 10 ²⁰ cm ⁻³ atoms of a p-type dopant,
Among them, 1 × 10 ¹⁸ to 1 × 10 ²⁰ cm ⁻³ atoms, preferably 2 × 10 ¹⁸ × 6 × 10 ¹⁹ cm ⁻³ atoms, and more preferably 2 × 10 ¹⁸ cm ⁻³ atoms.
By containing 10 ^{18 to} 5 × 10 ¹⁹ cm ⁻³ atoms, a p-type GaAs single crystal having a low dislocation density was obtained.

At this time, if the concentration of Si atoms is 1 × 10 ¹⁸ cm ⁻³ or more, a larger dislocation reducing effect can be obtained. Also, 1
If it exceeds × 10 ¹⁹ , fine precipitates due to impurities are likely to be generated, and cell growth due to compositional supercooling starts. Therefore, 1 × 10 ¹⁸ to 1 × Si is used as an impurity.
It is practical to contain 10 ¹⁹ cm ^-3 atoms.

As the p-type dopant, usually, C, B
e, Zn, Cd, Li, Ge, Au, Mn, Ag, P
An element selected from the group consisting of b, Co, Ni, Cu and Fe is used. Of these, Zn is most preferred. When Zn is 2 × 10 ^{18 to} 6 × 10 ¹⁹ cm ⁻³ , compositional supercooling hardly occurs during crystal growth and a low dislocation density can be obtained, which is particularly preferable. If it exceeds 6 × 10 ¹⁹ cm ⁻³ , compositional supercooling occurs during crystal growth, and the yield tends to decrease.

The carrier concentration is 1 × 10 ¹⁸ cm ⁻³ to
It is preferably 5 × 10 ¹⁹ cm ⁻³ as a p-type substrate.

Incidentally, p having an average dislocation density of 500 cm ^-2 or less is used.
According to the present invention, double doping of Si and a p-type dopant as described above is sufficient for the production of a single-type GaAs single crystal, but in order to obtain a single crystal with a lower dislocation density,
Further, B and / or S are represented as an atomic ratio to Si,
0.001 to 1000, among them 0.001 to 100,
In particular, it is preferable that the content be contained in the range of 0.05 to 50. Usually, the concentration of B and / or S is 1 × 10 ¹⁷ to 1 × 1
0 ²⁰ cm ^-3 atoms, preferably 1 × 10 ^{18 to} 5 × 10 ¹⁹ cm
It is contained in the range of ^-3 atoms.

As a method for producing a p-type GaAs single crystal having an average dislocation density of 500 cm ^-2 or less, a horizontal boat method such as a horizontal Bridgman method (HB method) or a horizontal temperature gradient solidification method (GF method), or a vertical Bridgman method Any of the vertical boat method such as the method (VB method) and the vertical temperature gradient solidification method (VGF method) may be adopted.

In the case of the horizontal boat method (HB, GF),
A horizontal (boat-type) growth vessel is used, and a seed crystal is arranged at one end of the growth vessel. On the other hand, in the vertical boat method (VB, VGF),
A seed crystal is placed at the lower end of a vertically elongated crucible-shaped growth vessel.

In each case, GaAs is provided at one end of the growth vessel.
disposing the s single crystal seed crystal and disposing at least a part of the GaAs crystal growth raw material and the dopant in the growth vessel; heating the growth vessel and the vicinity thereof to form a GaAs melt containing the dopant in the growth vessel. P-type GaAs including a step of adjusting a solution, a step of seeding, and a step of gradually cooling to grow a p-type GaAs single crystal
It is common in that it is a method for producing an s single crystal.

A feature of the present invention is that the p-type GaAs single crystal
Inside, Si and dopan showing p-type in GaAs single crystal
As the atomic ratio of the p-type dopant to Si,
Care should be taken to be in the range of 1.5 to 200 described above.
That is, usually, Si is 1 × 10 ¹⁷~ 5 × 10¹⁹cm^-3original
And the p-type dopant is 1 × 10¹⁸~ 1 × 10²⁰cm^-3original
The point of placing the dopant in the growth vessel so that it is included
Exists. When Zn is used as a p-type dopant,
Is 2 × 10¹⁸~ 6 × 10¹⁹cm^-3Arranged to be included in
Is preferred. B and / or as a dopant
When S is used, the above-described specific element for Si is used.
It is arranged so that the child ratio becomes 0.001 to 1000. Through
Always 1 × 10¹⁷~ 1 × 10²⁰cm^-3Atoms to be included
Place.

Although the method of the present invention is effective for both vertical and horizontal boat growth methods, a circular wafer can be obtained at a high yield, a large substrate can be obtained, and a single crystal having a lower dislocation density can be obtained. The vertical boat method is more preferable. According to the present invention, the average dislocation density is 500 cm ^-2 or less, the surface area (as one-sided area) exceeds 20 cm ² , the surface area of both sides exceeds 40 cm ² , the diameter exceeds 50.8 mm (2 inches), A large p-type GaAs single crystal semiconductor substrate having a size of 2.5 inches or more (about 31 cm ² or more on one side) or 3 inches or more (about 45 cm ² or more on one side) can be obtained. The single crystal semiconductor substrate of the present invention can efficiently obtain a circular wafer by the above-described boat growth method, but is not limited to the circular wafer, and may have any shape, such as a square wafer, as long as the substrate of the present invention is satisfied. It may be.

Even if at least a part of Si is replaced by doping with Se and / or Te impurities, the same effect as Si can be obtained.

As described above, the present invention relates to combining GaAs crystal with Si and a p-type dopant, or
By doping in combination with Si, B and / or S, and a p-type dopant, a p-type GaAs single crystal having a low dislocation density can be obtained. Here, since Si exhibits a dislocation-reducing effect at a concentration about one tenth of that of In, the doping amount of Si may be small, and compositional supercooling due to segregation in a crystal manufacturing process is unlikely to occur. For this reason, a low dislocation p-type GaAs single crystal can be obtained with a high yield.

The p-type GaAs thus obtained is
Single crystal and, p-type GaAs single crystal substrate dislocation density 500 cm ^-2 or less as compared with the conventional, since the lower single-crystal substrate having dislocation densities below a among them 400 cm ^-2 obtained, these compound semiconductor laser By using it as a substrate for use, a laser with high luminous efficiency and long life can be obtained.

Example 1 As shown in FIG. 1, a crucible (1) made of pBN (pyrolytic boron nitride) having a diameter of 3 inches was filled with a GaAs seed crystal (3) at the bottom, and 4000 g of GaAs polycrystal ( 4) and
50 g of B ₂ O ₃ (5) was charged. Furthermore, Zn (6) was added to 1.
After adding 5 g and 0.5 g of Si (7), it was vacuum-sealed in a quartz ampule (2).

Next, the quartz ampoule (2) is set in a growth furnace, heated by a heater (8), and a part of the GaAs polycrystal (4) and a part of the seed crystal (3) are melted for seeding. While maintaining a temperature gradient of 3 to 5 ° C./cm, cooling was performed to grow a GaAs single crystal.

A 3-inch (100 surface) GaAs substrate (one side surface area: 45 cm ² ) was cut out from the obtained single crystal.
After performing melt KOH etching at 400 ° C. for 30 minutes, the dislocation density was measured by observing with an optical microscope. Count the number of dislocations in the range of 1 × 1 mm in the field of view of the microscope,
The dislocation density per 1 cm ² was obtained by multiplying by 100. Similar measurements were performed at 37 points at 10 mm intervals to determine the average dislocation density.

According to the measurement result, the average dislocation density was 180 cm
^-2 . The carrier concentration of this substrate is 1.2 × 1
At 0 ¹⁹ cm ^-3 , a p-type conductivity type was exhibited. FIG. 2 shows the result of SIMS measurement of the impurity concentration in the substrate at this time.

When a total of five crystals were grown under these conditions, all the obtained crystals were single crystals.

Example 2 As shown in FIG. 3, the bottom of a quartz crucible (1) having a diameter of 3 inches was filled with a GaAs seed crystal (3), and 4000 was placed thereon.
g of GaAs polycrystal (4). Further Zn
After 1.5 g of (6) and 0.2 g of Si (7) were added, they were vacuum-sealed in a quartz ampule (2).

Next, the quartz ampoule (2) is set in a growth furnace, and a heater (8) is heated to melt a part of the GaAs polycrystal and the seed crystal to perform seeding. While maintaining the temperature gradient, the substrate was cooled to grow a GaAs single crystal.

From the obtained single crystal, a 3-inch (100) plane GaAs substrate was cut out and melted at 400 ° C. for 30 minutes.
After the OH etching, the dislocation density was measured in the same manner as in Example 1. The measurement results show that the average dislocation density is 380
cm ^-2 .

The carrier concentration of this substrate is 1.5 × 1
At 0 ¹⁹ cm ^-3 , a p-type conductivity type was exhibited. FIG. 2 shows the result of SIMS measurement of the impurity concentration in the substrate at this time.

When a total of five crystals were grown under these conditions, all the obtained crystals were single crystals.

Example 3 As shown in FIG. 4, a horizontal quartz boat (10)
(9) 2750 g, Zn (6) 3.0 g and Si (7)
Is filled with 0.2 g. A GaAs seed crystal (3) is arranged at one end of the quartz boat (10). And 3000g
Is vacuum-sealed in a quartz ampoule (2) together with the metal arsenic (11).

Next, the quartz ampoule (2) is set in a growth furnace, the heater (8) is heated to synthesize a GaAs melt, and a part of the GaAs seed crystal (3) is melted and seeded. While maintaining a temperature gradient of 0.5 to 3 ° C./cm, cooling was performed to grow a GaAs single crystal.

From the obtained single crystal, a 2-inch GaAs substrate having a (100) plane was cut out and melted at 400 ° C. for 30 minutes.
After performing the OH etching, the dislocation density was measured in the same manner as in Example 1 except that measurement was performed at 69 points at intervals of 5 mm. The measurement results show that the average dislocation density is 420 cm ^-2
Met.

The carrier concentration of the GaAs substrate was 2.1 × 10 ¹⁹ cm ^-3 , indicating a p-type conductivity. Table 1 shows the result of SIMS measurement of the impurity concentration in the substrate at this time. Further, when a total of five crystals were grown under these conditions, all the obtained crystals were single crystals.

Comparative Example 1 A GaAs single crystal was grown in the same manner as in Example 1 except that the amount of Si added was 0.01 g. The GaAs obtained at this time
When the dislocation density of the s substrate was measured under the same conditions as in Example 1, the in-plane average was 1810 cm ^-2 . FIG. 2 shows the result of SIMS measurement of the impurity concentration in the substrate at this time.

Comparative Example 2 G was the same as in Example 1 except that the amount of Si added was 1.5 g.
The growth of the aAs single crystal was performed five times, but only one single crystal was obtained by generating many fine precipitates due to impurities. When the dislocation density of the GaAs substrate cut out from the single crystal obtained at this time was measured under the same conditions as in Example 1, the average in-plane was 2840 cm ^-2 . Table 1 also shows the results of SIMS measurement of the impurity concentration in the substrate at this time.

As shown in the table of FIG. 2, all of Examples 1 to 3 according to the present invention are different from Comparative Examples 1 and 2 in the concentration of Zn and Si or Zn and Si and B. Depending on the combination, the number of dislocations per unit area is 500cm
^It can be understood that it becomes ^-2 or less.

FIG. 5 shows the number of crystal dislocation defects (EPD) on the (100) plane of the single crystal obtained according to the present invention.
It is an example of distribution. It can be understood that the dislocation density at any point is a value smaller than the average dislocation density of any of Comparative Examples 1 and 2.

[0052]

As described above with reference to the embodiments, according to the present invention, it is possible to obtain a p-type GaAs single crystal with low dislocation by double doping with Si and a p-type dopant. As a result, a highly efficient and long-lived compound semiconductor laser, a light emitting diode, and the like can be realized from a low dislocation p-type GaAs single crystal substrate.

[Brief description of the drawings]

FIG. 1 is a view schematically showing an apparatus used for producing a single crystal of the present invention, and is a view for explaining a first embodiment.

FIG. 2 is a table showing measured values of Examples and Comparative Examples.

FIG. 3 is a view schematically showing an apparatus used for producing a single crystal of the present invention, and is a view for explaining Example 2.

FIG. 4 is a view schematically showing an apparatus used for producing a single crystal of the present invention, and is a view for explaining a third embodiment.

FIG. 5 is an example showing a (100) plane dislocation (EPD) distribution of a single crystal obtained by the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Crucible made of pBN (pyrolytic boron nitride) 2 Quartz ampoule 3 GaAs seed crystal 4 GaAs polycrystal 5 B ₂ O ₃ 6 Zn 7 Si 8 Heater 9 Ga 10 Quartz boat 11 Metal arsenic

Claims (29)

[Claims] 1. A p-type GaAs single crystal comprising, as a dopant, a dopant exhibiting a p-type with Si and GaAs single crystal in an atomic ratio of the p-type dopant to Si in a range of 1.5 to 200. crystal. 2. The p-type GaAs single crystal according to claim 1, wherein the atomic ratio of the p-type dopant to Si is 2 to 1.
A p-type GaAs single crystal characterized by being included in the range of 00. 3. The p-type GaAs single crystal according to claim 1, wherein Si contains 1 × 10 ^{17 to} 5 × 10 ¹⁹ cm ^-3 atoms. 4. The p-type GaAs single crystal according to claim 3, wherein Si contains 1 × 10 ¹⁷ to 1 × 10 ¹⁹ cm ^-3 atoms. 5. The p-type GaAs single crystal according to claim 1, wherein the p-type dopant is 1.1 × 10 ¹⁷
P-type G containing 〜1 × 10 ²⁰ cm ^-3 atoms
aAs single crystal. 6. The p-type GaAs single crystal according to claim 5, wherein the p-type dopant is 2 × 10 ^{18 to} 6 × 10
A p-type GaAs single crystal containing ¹⁹ cm ^-3 atoms. 7. The p-type GaAs single crystal according to claim 1, wherein the p-type dopant is C, Be, Zn, C
d, Li, Ge, Au, Mn, Ag, Pb, Co, N
A p-type GaAs single crystal, which is an element selected from the group consisting of i, Cu, and Fe. 8. The p-type GaAs single crystal according to claim 7, wherein the p-type dopant is Zn. 9. The p-type GaAs single crystal according to claim 1, further comprising B and / or S as a dopant.
A p-type GaAs single crystal, which is contained in an atomic ratio to i in a range of 0.001 to 1000. 10. The p-type GaAs single crystal according to claim 9, wherein B and / or S is 1 × 10 ¹⁷ to 1 × 10 ²⁰ cm.
A p-type GaAs single crystal comprising ^-3 atoms. 11. The p-type GaAs single crystal according to claim 1, wherein at least a part of Si is made of Se and / or Te.
A p-type GaAs single crystal, characterized in that: 12. The p-type GaAs single crystal according to claim 1, wherein said carrier concentration is 1%.
A p-type GaAs single crystal having a size of × 10 ^{18 to} 5 × 10 ¹⁹ cm ⁻³ . 13. A dopant comprising 1 × 10 ¹⁷ to Si
1 × 10 ¹⁹ cm ⁻³ atoms, and a p-type dopant containing 1 × 10 ¹⁹ cm ⁻³ atoms
A p-type GaAs single crystal comprising 10 < ¹⁸ > to 1 * 10 < ²⁰ > cm <^-3> atoms. 14. The p-type GaAs single crystal according to claim 13, wherein Si contains 1 × 10 ¹⁷ to 1 × 10 ¹⁹ cm ^-3 atoms, and Zn as a p-type dopant has 2 × 10 ^{18 to} 6 × 10 ^18.
A p-type GaAs single crystal containing ^{x10 19} cm ^-3 atoms. 15. The p-type GaAs single crystal according to claim 13, wherein the p-type dopant is C, Be, Zn,
Cd, Li, Ge, Au, Mn, Ag, Pb, Co, N
A p-type GaAs single crystal, which is an element selected from the group consisting of i, Cu, and Fe. 16. The p-type GaAs single crystal according to claim 15, wherein the p-type dopant is Zn. 17. The p-type GaAs single crystal according to claim 13, further comprising B and / or S as a dopant.
Is a 1 × 10 ¹⁷ to 1 × 10 ²⁰ cm ⁻³ atom. 18. The p-type GaAs single crystal according to claim 13, wherein at least a part of Si is made of Se and / or T
A single crystal of p-type GaAs, wherein the single crystal is substituted with e. 19. The p according to claim 13, wherein
In the type GaAs single crystal, the carrier concentration is 1 × 10 ¹⁸
P-type GaAs having a size of about 5 × 10 ¹⁹ cm ⁻³
Single crystal. 20. A method for producing a p-type GaAs single crystal, comprising the steps of:
i is 1 × 10 ^{17 to} 5 × 10 ¹⁹ cm ⁻³ atoms, and GaAs
Production of a p-type GaAs single crystal, characterized in that a dopant is filled in a growth vessel so that a dopant exhibiting a p-type in a single crystal is contained in a range of 1.5 to 200 as an atomic ratio with respect to Si. Method. 21. A method of manufacturing a p-type GaAs single crystal, comprising: disposing a GaAs single crystal seed crystal at one end of a growth vessel; and disposing at least a part of a GaAs crystal growth material and a dopant in the growth vessel. Heating the growth vessel and its vicinity to adjust a GaAs melt containing the dopant in the growth vessel; seeding; and gradually cooling to grow a p-type GaAs single crystal. 1 × 10 ^{17 to} 5 × 10 ¹⁹ as the dopant
cm- ³ atoms and a dopant showing a p-type in a GaAs single crystal are filled in the growth vessel so as to be included in an atomic ratio to Si in a range of 1.5 to 200. A method for producing a p-type GaAs single crystal. 22. A method of manufacturing a p-type GaAs single crystal, comprising: disposing a GaAs single crystal seed crystal at one end of a growth vessel; and disposing at least a part of a GaAs crystal growth material and a dopant in the growth vessel. Heating the growth vessel and its vicinity to adjust a GaAs melt containing the dopant in the growth vessel; seeding; and gradually cooling to grow a p-type GaAs single crystal. 1 × 10 ^{17 to} 5 × 10 ¹⁹ as the dopant
cm- ³ atoms and a dopant exhibiting a p-type in a GaAs single crystal are filled in the growth vessel so as to be contained in a range of 1 × 10 ¹⁸ to 1 × 10 ²⁰ cm ⁻³ atoms. A method for producing a p-type GaAs single crystal. 23. The p-type GaAs according to claim 21 or 22.
The method for producing an s single crystal, wherein the growth vessel is a growth vessel for a horizontal boat. 24. The p-type GaAs according to claim 21 or 22.
In the method for producing an s single crystal, the growth vessel is a growth vessel for a vertical boat, wherein the p-type GaAs single crystal is produced. 25. The method for producing a p-type GaAs single crystal according to claim 22, wherein Si is used as the dopant in an amount of 1 × 10 ¹⁷ to 1 × 10 ^19.
cm ^-3 atoms, and, as contained ^{2 × 10 18 ~6 × 10 19} cm -3 atomic Zn as dopant for the p-type in GaAs single crystal, characterized in that filling the growth vessel A method for producing a p-type GaAs single crystal. 26. A p-type GaAs according to claim 21 or 22.
In the method for producing an s single crystal, the dopant
And B and / or S is 1 × 10¹⁷~ 1 × 10 ²⁰cm^-3atom
Filling the growth vessel with dopants as included
A method for producing a p-type GaAs single crystal, characterized in that: 27. A p-type GaAs according to claim 21 or 22.
In the method for producing an s single crystal, the growth vessel is filled so that B and / or S are contained as dopants in an atomic ratio to Si in a range of 0.001 to 1000. For producing a p-type GaAs single crystal. 28. A p-type GaAs single crystal semiconductor substrate having an average transition density of 500 cm ⁻² or less and a surface area of 20 cm ² or more. 29. The p-type GaAs single-crystal semiconductor substrate according to claim 28, wherein the single-crystal substrate has a diameter larger than 50.8 mm.