JPH10256277A - Method of forming p-type ii-vi compound semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a p-type dopant which can easily realize p-type carrier concentration in a semiconductor for not less than prescribed quantity through the use of an organic compound shown by a specified regular equation as p-type dopant. SOLUTION: As an N-material of a p-type dopant, an organic compound of a molecular having a covalent bond between a 2 atom of group II element and an N atom to serve as a dopand and a covalent bond between an N atom and an Si atom is used. Then, R<1> MNHSiR<2> 3 , R<1> MN(SiR<2> 3 )2 and (R<1> M)2 NSiR<2> 3 are used as the compounds, where R<1> is a hydrocarbon group, R<2> is hydrogen or a hydrocarbon group, M is zinc, magnesium or cadmium. A p-type dopant synthesizer 35 synthesizes p-type dopant and it is transported on a GaAs substrate 48 provided for a reaction furnace 46 by gas vapor and the p-type II-VI compound semiconductor is vapor-grown on the substrate. Thus, the p-type carrier concentration of not less than 1×10<17> cm<-3> can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a p-type II-VI compound semiconductor, and more particularly to a method of forming a p-type II-VI compound semiconductor using a novel p-type dopant suitable for forming a p-type II-VI compound semiconductor.
The present invention relates to a method for forming a group II-VI compound semiconductor.

[0002]

2. Description of the Related Art Group II-VI compound semiconductors are promising substances as semiconductor materials emitting blue or green light. Among these, ZnSe-based semiconductors are the most promising, and ZnSe alone is used, or a group II-VI using a group II element of Mg and / or Cd and a group VI element of S and / or Te as a modifier. Compound semiconductors are expected. As a dopant exhibiting the p-type conductivity of the II-VI compound semiconductor, attention has been paid to nitrogen. However, in the preparation of a p-type II-VI compound semiconductor thin film typified by ZnSe using a conventional metal organic chemical vapor deposition (MOCVD) method, even if nitrogen is introduced into a semiconductor layer using nitrogen as a dopant, There is a problem that a p-type II-VI compound semiconductor having a concentration of 10 ¹⁷ cm ⁻³ or more cannot be manufactured. That is, in the case of a ZnSe-based semiconductor, the addition of nitrogen atoms is considered to be most promising for the growth of a p-type semiconductor thin film. Therefore, many nitrogen sources have been studied as p-type dopants. However, among compounds that have been tried as conventional nitrogen raw materials, those in which a nitrogen atom is doped into a ZnSe-based semiconductor crystal by 10 ¹⁸ cm ⁻³ or more have been found. In fact, efficient doping has not been realized because the conversion rate is extremely low. In addition, using a MBE apparatus, a semiconductor substrate is irradiated with a molecular beam of zinc and selenium under a high vacuum, and in a molecular beam epitaxy (MBE) method for growing ZnSe, N radicals generated by plasma decomposition of nitrogen by high frequency discharge are doped. There are also suggestions on how to do this. This method itself reduces the carrier concentration to 1
Although a high concentration of 0 ¹⁷ cm ^-3 can be obtained, the equipment is expensive and the use of a high vacuum is required, so the productivity is poor, and the equipment already has the equipment or a special semiconductor is manufactured. Except for the case, it is difficult to adopt as a method for manufacturing an inexpensive p-type II-VI compound semiconductor.

[0003] p-type II by vapor phase growth such as MOCVD
In a method for forming a Group VI compound semiconductor, ammonia (NH ₃ ) and tertiary butylamine (tBu) are mainly ones of compounds conventionally studied as a nitrogen source.
NH ₂ ), triallylamine (TAN) and the like.

[0004] NH ₃ is a nitrogen source used in many experiments as a p-type dopant. However, in any of the experiments, p-type ZnSe having a carrier concentration of 10 ¹⁶ cm ⁻³ or more has not been realized. According to secondary ion mass spectrometry (SIMS), the nitrogen atom concentration in the ZnSe thin film using NH ₃ as a raw material of the p-type dopant was 10 ¹⁸ c
m ⁻³ or more, and in the photoluminescence spectrum of the ZnSe thin film at 10 K, the more the donor-acceptor pair emission becomes dominant, the more Zn in the case of using NH _3.
The addition of a sufficient amount of nitrogen atoms to the Se thin film and the generation of acceptors have been confirmed, but the p-type carrier concentration is 1 ×
It was 10 ¹⁶ cm ^-3 or less, and the activation rate of N atoms was as low as 1% or less.

Further, as an example of using tBuNH ₂ as a nitrogen source, diethylzinc (DEZn) and dimethyl selenium (DMSe) are used as group II and group VI sources, and ultraviolet light is emitted to lower the growth temperature to 350 ° C. In the irradiated system, p-type ZnS having a p-type carrier concentration of 2 × 10 ¹⁷ cm ^-3
e has been produced (Journal of
Electronic Materials (J. Electronic Mater
ials), 23, 263 (1994)). However, in this method, it is difficult to uniformly irradiate light over a wide area, and deposits containing ZnSe as a main component are deposited on the inner wall of the growth furnace. It is considered a disadvantageous manufacturing method.

[0006] As an example of using TAN as a nitrogen source, Group II and Group VI sources are dimethyl zinc (DMZ).
n) triethylamine (TEN) adduct (DMZn
(TEN)) and ditertiary butyl selenium (DTBS)
e) the p-type carrier concentration is 1.2 × 10
^It has been reported that a p-type ZnSe of ¹⁷ cm ^-3 was obtained (J. Crystal Gr.
owth), 145, 918 (1994)). However, the reporters of the paper report that reproducibility was not obtained in the additional test, and the effectiveness of TAN, a tertiary amine, for p-type doping has not yet been confirmed. MOC of p-type II-VI compound semiconductor
In growth by the VD method, it has been proposed to use a lower trialkylamine adduct of a lower dialkylzinc as a growth raw material or a p-type dopant (Japanese Patent Application Laid-Open No. H06-26139).
-29227). In the above-mentioned p-type dopant, the zinc atom of the lower dialkyl zinc and the nitrogen atom of the lower trialkylamine in the molecule have a coordinate bond, and this bond is easily broken by heating the substrate during film growth. Since the released lower trialkylamine has low degradability, p-type II
-Addition of nitrogen into the group VI compound semiconductor is not sufficiently performed,
The resulting carrier concentration in the p-type II-VI group compound semiconductor is also at the level of 10 ¹⁶ cm ^-3 , and further improvement is required.

Further, bis [bis (trimethylsilyl) amide] zinc (hereinafter referred to as TMSAZ) is used as a nitrogen source.
As an example of using Zn, a report has been made of a ZnSe compound semiconductor made by combining DEZn and hydrogen selenide (H ₂ Se) as a group II element and a group VI element raw material (Journal of J. Electronic Materials ) 21
Volume, p. 361 (1992)) and DMZn (TEN) as a group II element and group VI element raw material
Of ZnSe compound semiconductor in combination with DTBSe (Journal of Crystal growth, 169, 243 (199)
6)), although evidence for the introduction of nitrogen into ZnSe was obtained, but the concentration was unknown, and P-type ZnSe
No compound semiconductor has been obtained.

[0008] As described above, Zn by the conventional vapor phase growth method is used.
In the growth of the Se thin film, as described above, a number of nitrogen-containing compounds including NH ₃ were examined as a nitrogen source, but the p-type carrier concentration was 1 × 10 ¹⁷ cm ^−3.
A nitrogen-containing compound capable of stably producing the above p-type ZnSe-based semiconductor thin film has not been found. Therefore, a p-type dopant comprising a nitrogen-containing compound for stably and inexpensively forming a p-type carrier concentration of 10 ¹⁷ cm ^-3 or more for a promising p-type II-VI compound semiconductor, particularly a p-type ZnSe-based semiconductor Was required.

[0009]

SUMMARY OF THE INVENTION The present invention relates to MOCVD.
In forming a p-type II-VI group compound semiconductor by the method,
A p-type dopant capable of easily achieving a p-type carrier concentration of 1 × 10 ¹⁷ cm ⁻³ or more in the semiconductor is developed, and a p-type II-VI group compound semiconductor mainly composed of ZnSe as a main component is formed. The aim is to develop a method.

[0010]

SUMMARY OF THE INVENTION The present invention provides: 1) a p-type II-VI compound semiconductor thin film on a substrate by a vapor phase growth method using a group II element source, a group VI element source and a p-type dopant. in p-type group II-VI compound semiconductor forming methods for growing, as the p-type dopant, the general formula (1) ~ (3) R 1 MNHSiR 2 3 ···· (1) R 1 MN (SiR 2 3 ) ₂ .... (2) or ^{_{(R 1 M) 2 NSiR 2}} 3 ···· (3) ( provided that, R ¹ is a hydrocarbon group, R ² is hydrogen or a hydrocarbon group, M is zinc, magnesium Or cadmium.) P-type II-
A method of forming a group VI compound semiconductor,

2) In the organic compounds represented by the general formulas (1) to (3), R ¹ is an aliphatic hydrocarbon group having up to 4 carbon atoms or a phenyl group, and R ² is hydrogen or up to 6 carbon atoms. method of forming a hydrocarbon group 1) as claimed in p-type group II-VI compound semiconductor, 3) the general formula (1) to (an organic compound represented by 3), 1 R ² is a methyl group) Or p-type according to 2)
Method of forming a Group II-VI compound semiconductor, 4) the general formula _{^{(4) R 1 2 Zn ·}} (NR 3 3) n ···· (4) ( however, aliphatic hydrocarbons R ¹ up to 4 carbon atoms R ³ is a hydrocarbon group, and n is 0 or
And 2 or less. ) And bis [bis (trimethylsilyl) amide] zinc (Z
n [N (SiMe ₃ ) ₂ ] ₂ ), a product synthesized by reacting with bis (trimethylsilyl) amine (HN (SiMe ₃ ) ₂ or trimethylsilylamine (H ₂ N (SiMe ₃ )) 1) The method for forming a p-type II-VI compound semiconductor according to 1), which is used as a dopant,

5) a first step of synthesizing a p-type dopant, a second step of transporting the p-type dopant in a vapor phase onto the substrate, a raw material of a group II element, a raw material of a group VI element, and a p-type dopant And the third step of vapor-growing the p-type II-VI group compound semiconductor on the substrate by mixing the p-type II-VI compound semiconductor on the substrate is performed continuously in the same apparatus. A method of forming a group VI compound semiconductor, 6) a first step of synthesizing a p-type dopant and a second step of transporting the p-type dopant in a gas phase onto a substrate in the same reaction furnace. And bis [bis (trimethylsilyl) amide] zinc (Zn [N (SiMe ₃ ) ₂ ]
₂ ), bis (trimethylsilyl) amine (HN (SiM
e ₃ ) ₂ or trimethylsilylamine (H ₂ N (Si
5) The method for forming a p-type II-VI compound semiconductor according to 5), which is performed by mixing with at least one of Me ₃ )), and 7) a growth temperature of 200 to 400 ° C. and a reaction pressure of 10 t.
The above object is achieved by developing a method for forming a p-type II-VI compound semiconductor according to any one of 1) to 6) wherein the p-type II-VI compound semiconductor thin film is vapor-phase grown at orr to normal pressure. Achieved.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Among the p-type II-VI compound semiconductors, ZnSe-based semiconductors are the most promising semiconductor materials and have been studied extensively. As the p-type dopant used for this, nitrogen has been most widely studied. In the present invention, a ZnSe-based semiconductor is used as a p-type II-VI compound semiconductor, and a covalent bond between a nitrogen atom and a Zn atom and between the nitrogen atom and a Si atom as a group II element of a p-type dopant used therein. Is described as a typical example of an organic compound having in a molecule. When growing a ZnSe-based material, Mg or Cd
This is because it is convenient because it does not need to be affected at all. However, in a p-type II-VI compound semiconductor containing Mg or Cd as a constituent element of the p-type II-VI compound semiconductor, the p-type dopant is between a nitrogen atom and a Mg atom and between a nitrogen atom and a cadmium atom. Has a covalent bond to
At the same time, it is preferable to form a p-type II-VI group compound semiconductor using an organic compound having a covalent bond between the nitrogen atom and the Si atom.

Heretofore, it has been considered that the reason why the activation rate of nitrogen atoms (N) in ZnSe crystals is low is that hydrogen atoms (H) incorporated into ZnSe crystals inhibit N acceptorization. However, the present inventors consider that the cause of the low activation rate of N is not only the inhibition by H, but also that the majority of N exists in the interstitial position in the ZnSe crystal,
It was also considered that the fact that the e-lattice points were not efficiently replaced was also a major factor. When a nitrogen source such as ammonia or amines is used as a p-type dopant as in a conventional report, II is necessary for replacing N with a Se lattice point.
The formation of a covalent bond between a group III element and N is inefficient due to the low decomposability of these p-type dopants, and this is the reason why
This is considered to be a factor that the incorporation into Se lattice points in the Se crystal is small.

That is, the present inventors have considered this problem as a nitrogen source of a p-type dopant, wherein Zn as a Group II element and an N atom as a dopant have a covalent bond in a molecule, and the N atom and Si We thought that the problem could be solved by using an organic compound having a covalent bond with an atom. General formula as the compounds (1) ~ (3) R 1 MNHSiR 2 3 ···· (1) R 1 MN (SiR 2 3) 2 ···· (2) or (R ¹ M) ₂ NSiR ² ₃ ... (3) (wherein, R ¹ is a hydrocarbon group, R ² is hydrogen or a hydrocarbon group, M is. showing zinc, either a magnesium or cadmium) include the compounds represented by Can,
By using these compounds as p-type dopants, N atoms can be efficiently supplied to the grown ZnSe surface, and the N atoms are efficiently substituted at Se lattice points and incorporated into the ZnSe crystal, so that a high activation rate as an acceptor is obtained. Was obtained, and a p-type ZnSe crystal of 10 ¹⁷ cm ⁻³ or more was easily obtained. In the above p-type dopant compound of the present invention, the group II element Zn and the dopant N atom have a covalent bond in the p-type dopant molecule, and the N atom and the Si atom are also covalently bonded in the same molecule. Therefore, one of the conventional techniques (Japanese Patent Laid-Open No. 6-2922)
This is essentially different from the adduct compound in which Zn and the N atom are coordinated and used in the invention described in No. 7). Further, in the p-type dopant compound of the present invention, since the number of H atoms bonded to N in the molecule is smaller than that of a conventional nitrogen source such as ammonia or amines, the p-type dopant compound is introduced into the crystal due to the nitrogen compound. H atoms can be expected to decrease. Further, Si bonded to N in the p-type dopant compound is easily released out of the system at the time of crystal growth of p-type ZnSe, so that an amount of Si that inhibits p-type conversion of ZnSe is contained in the ZnSe crystal. It was not considered that this would be introduced in the future, and it was confirmed that this estimation was correct as a result.

In the formation of the p-type II-VI compound semiconductor of the present invention, examples of a method of synthesizing a compound used as a p-type dopant include a method of synthesizing in a solvent and a method of synthesizing without a solvent. As a method of synthesizing in a solvent, for example, in a solvent such as benzene, toluene, dioxane, tetrahydrofuran, n-pentane,
In a compound having a covalent bond between a nitrogen atom and a Zn atom and between the nitrogen atom and a Si atom, the aforementioned DMZ
n, DEZn, DMZn (TEN), dipropyl zinc ((Pr) ₂ Zn), diisopropyl zinc ((iPr)
₂ Zn), dibutyl zinc ((Bu) ₂ Zn) or ditertiary butyl zinc ((tBu) ₂ Zn), and dissolving an organic zinc therein.
It can be synthesized by a method such as introducing N (SiMe ₃ ) ₂ or H ₂ N (SiMe ₃₎ and causing a reaction.

The compound having a covalent bond between a Group II element and nitrogen and at least one covalent bond between the nitrogen atom and the Si atom in the molecule used as a p-type dopant in the present invention has been known as a substance. Has not been used in MOCVD as a p-type dopant for a p-type II-VI compound semiconductor. Examples of synthesis include DEZn
EtZN (SiMe ₃ )
₂ got a report (Organometallics
s), 1984, p. 1187 (1984).

[0018] As a method for synthesizing without solvent, vacuum or Ar, nitrogen, the organic zinc compound in a sealed container an inert gas atmosphere such as hydrogen [R ¹ ₂ Zn or R ¹ ₂ Zn
(NR ³ ₃ ) _n etc. (where n is 0 ≦ n ≦ 2), and then the above-mentioned TMSAZ, HN
It can be synthesized by introducing (SiMe ₃ ) ₂ or H ₂ N (SiMe ₃ ) and causing a reaction.
The compound obtained by these methods is generally used as a p-type dopant raw material after removing unreacted raw materials and reaction by-products or the like. Note that instead of a Zn compound,
By using the same organic compound of Mg or Cd, a compound having a covalent bond between a nitrogen atom and a group II element atom and between the nitrogen atom and a Si atom in a molecule can be obtained in the same manner. Can be used.

As a preferred embodiment of the present invention, FIG.
It is preferable to use an apparatus as shown in FIG. That is, the first step of synthesizing the p-type dopant in the p-type dopant synthesizer 35 and the reaction furnace 4
A second step of transporting the substrate onto the GaAs substrate 48 provided in Step 6, and mixing the raw material of the Group II element, the raw material of the Group VI element and the p-type dopant to form the p-type II-VI compound semiconductor on the substrate. When the third step of vapor phase growth and the p-type dopant are not taken out on the way and these steps are continuously performed in the same apparatus to form a p-type II-VI compound semiconductor, impurities This is advantageous because a semiconductor thin film with less contamination can be produced with high productivity. According to another preferred embodiment of the present invention, a first step of synthesizing the p-type dopant and a second step of transporting the p-type dopant in a gas phase onto a GaAs substrate provided in a reaction furnace are provided. When the reaction is carried out in the same reactor without dividing, the p-type dopant is not required to be transported, and a p-type II-VI group compound semiconductor thin film with less contamination of impurities can be produced with good productivity.

The temperature used in the above synthesis reaction is under cooling,
Room temperature or heating may be used, and the pressure may be reduced pressure, normal pressure, or increased pressure, but the reaction conditions are between the nitrogen atom and the group II element atom used as the p-type dopant and between the nitrogen atom and the Si atom. An organic compound having a covalent bond between them, for example, the above-mentioned organozinc compound, TMSAZ, HN (Si
It depends on the combination with Me ₃ ) ₂ or H ₂ N (SiMe ₃ ) and the reaction time, but has physical properties such that the obtained p-type dopant has a vapor pressure or sublimation that can be used in the gas phase. Then, any condition may be applied.

Examples of the Zn raw material as the raw material of the Group II element used for the vapor phase growth of the p-type II-VI compound semiconductor of the present invention include DMZn, DEZn, DMZn (TEN), and dipropylzinc ((Pr) ₂ Zn), diisopropyl zinc ((iPr) ₂ Zn), dibutyl zinc ((Bu)
₂ Zn), ditertiary butyl zinc ((tBu) ₂ Z
n) and the like. Examples of Mg raw materials include bis (cyclopentadienyl) magnesium ((Cp) ₂ M
g), bis (methylcyclopentadienyl) magnesium ((MeCp) ₂ Mg), bis (isopropylcyclopentadienyl) magnesium ((iPrCp) ₂ M
g) and the like, and examples of the Cd raw material include dimethylcadmium (DMCd).

Examples of the group VI element used in the vapor phase growth of the present invention include Se raw materials such as ditertiary butyl selenium (DTBSe) and diisopropyl selenium (D
IPSe), dimethyl selenium (DMSe) and the like. An example of the S raw material is diethyl sulfur (DES).
Examples of Te raw materials include di-tert-butyl tellurium (DTBTe) and diisopropyl tellurium (DIPT).
e), dimethyl tellurium (DMTe) and the like.

Using the p-type dopant of the present invention, p-type II
When the group-VI compound semiconductor is vapor-phase grown, the growth temperature is 200 to 400 ° C., preferably 250 to 340 ° C., and the reaction pressure is 10 torr to normal pressure, preferably 50 to 350 t.
The condition of orr is used. The method of forming a p-type II-VI compound semiconductor in the present invention has been described using a metal organic chemical vapor deposition (MOCVD) method as a vapor phase growth method. It can be applied to the molecular beam epitaxy (MBE) method and the (MOMBE method). In addition, the p-type II-VI group compound semiconductor which is an object of the present invention is often a ZnSe-based semiconductor mainly composed of ZnSe, and in that case, the compound semiconductor is represented by the general formula (5): Zn _x Mg _y Be _z Cd _{1 -XY over Z S 1-ab Te a Se} b ···· (5) ( where, 0 <x ≦ 1,0 ≦ y <1,0 ≦ z <1,0 <x
+ Y + z ≦ 1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1, 0 ≦ a + b ≦
It can be represented by 1). More specifically, ZnSe,
ZnSSe, ZnCdSe, ZnBeSe, ZnMgS
It is a semiconductor such as Se, ZnS or ZnTe.

According to the method of forming a p-type II-VI compound semiconductor according to the present invention, the p-type dopant is shared between a nitrogen atom and a group II element atom and between the nitrogen atom and a Si atom in a molecule. Organic compounds having a bond, preferably an organic compound having a covalent bond between a nitrogen atom and a group II element atom and between the nitrogen atom and a Si atom in the molecule are represented by the general formulas (1) to (3): _{^{1 MNHSiR 2 3 ···· (1)}} R 1 MN (SiR 2 3) 2 ···· (2) or _{^{(R 1 M) 2 NSiR 2}} 3 ···· (3) ( provided that, R ¹ is A hydrocarbon group, preferably an aliphatic hydrocarbon group having up to 4 carbon atoms or a phenyl group, R ² is hydrogen or a hydrocarbon group, preferably hydrogen or an aliphatic chain hydrocarbon group having up to 6 carbon atoms, more preferably methyl And M is zinc, magnesium or Represents one of cadmium. Organic compound or represented by the general _{^{formula) (4) R 1 2 Zn}} · (NR 3 3) n ···· (4) ( provided that, R ¹ is of up to 4 carbon atoms An aliphatic hydrocarbon group or a phenyl group; R ³ represents a hydrocarbon group;
And 2 or less. ) And bis [bis (trimethylsilyl) amide] zinc (Z
n [N (SiMe ₃ ) ₂ ] ₂ ), a product synthesized by reacting with bis (trimethylsilyl) amine (HN (SiMe ₃ ) ₂ or trimethylsilylamine (H ₂ N (SiMe ₃ )) When used as a dopant, in the growth of an N-doped ZnSe-based semiconductor thin film, N atoms are efficiently replaced with Se lattice points, and the ratio of the number of H to the number of N in the crystal (H / N
Ratio) can be reduced, so that a p-type II-VI compound semiconductor having a carrier concentration of 10 ¹⁷ cm ⁻³ or more can be formed.

The p-type II-VI compound semiconductor of the present invention can be produced by a conventional method of forming a p-type II-VI compound semiconductor by MOCVD using the above-mentioned p-type dopant. There may be. In this case, the p-type dopant used for forming the p-type II-VI compound semiconductor may be separately synthesized, and the p-type dopant may be introduced into the MOCVD apparatus as usual to grow the p-type II-VI compound semiconductor on the substrate. However, in order to prevent the handling of the dopant and the incorporation of other impurities, it is preferable that the synthesis of the p-type dopant and the growth of the p-type II-VI compound semiconductor be performed in the same apparatus. Using this p-type dopant, p-type II-VI
Growth temperature of 200 ~
400 ° C., preferably 250 to 340 ° C., and a reaction pressure of 1
By performing vapor phase growth under the conditions of 0 torr to normal pressure, preferably 50 to 350 torr, it is possible to grow a p-type II-VI group compound semiconductor having properties preferable for high-luminance blue to green light emission.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is for explaining a schematic configuration of a compound semiconductor forming apparatus used in the present invention, and is known as a general MOCVD growth apparatus. In the figure, 11 is a high-purity Ar gas cylinder used as a carrier gas, 12 is a high-purity H ₂ gas cylinder used as a carrier gas, 13 is a high-pressure gas cylinder containing 10% AsH ₃ of H ₂ balance, 14 is a high-purity NH ₃ gas cylinder, 15 Is a stainless steel bottle filled with a liquid DEZn as a Zn raw material, 16 is a stainless steel bottle filled with a raw material used as a p-type dopant, and 17 is a stainless steel bottle filled with a liquid DTBSe which is a group VI element raw material. 2
6 is a reactor for growing a ZnSe thin film, 27 is a mounting table and a heater for heating the substrate, 28 is a GaAs substrate, 25
Is a valve for switching the carrier gas, 20 to 24 are mass flow controllers for controlling the flow rate, 29 is a vacuum pump, 30 is a detoxification facility, and 18 and 19 are carrier gas purification devices.

Each of the above-mentioned raw materials is flow-controlled by a flow controller, and is introduced into the reaction furnace 26 at a reduced pressure (160 torr) together with an argon carrier gas. However, immediately before the growth, the carrier gas is changed to H ₂ using the valve 25.
And the GaAs substrate is thermally cleaned in an AsH ₃ + H ₂ atmosphere. Next, a specific method for forming a p-type II-VI group compound semiconductor will be described.

(Synthesis of p-type dopant) First, at room temperature and normal pressure, the vessel into which 30 ml of benzene had been introduced was replaced with argon, and then 10 mmol of TMSAZ was introduced. The temperature of the solution was set at 50 ° C. Next, 10 mmol of DE
Zn was introduced into the vessel, and the solution was stirred for 1 hour to complete the reaction. Next, the solvent was removed in vacuo and further recrystallized from n-pentane to obtain a solid substance. The obtained compound is analyzed by elemental analysis, molecular weight measurement, NMR measurement amount, etc.
The material was mainly EtZnN (SiMe ₃ ) ₂ . Next, the obtained compound was filled in a stainless steel bottle 16 and attached to a line of a MOCVD growth apparatus.

(MOCVD method) Zn by MOCVD method
In the growth of the Se thin film, a (100) plane j is used as a substrate.
A ust single-crystal GaAs single crystal substrate (diameter: 2 inches, thickness: 350 μm) was used. The substrate is first kept in 96% concentrated sulfuric acid at 20 ° C. for 1 minute for the purpose of removing a damaged layer on the substrate surface, and then sulfuric acid at 60 ° C. (concentration 96% by weight): hydrogen peroxide solution (concentration 35% by weight) : Water = 8: 1:
The substrate surface was removed by several μm with an etchant of 1 (volume ratio). Then, after rinsing in running water of ultrapure water and pulling up, water droplets on the surface were removed by dry nitrogen blow and dried by incandescent lamp irradiation. The washed substrate is placed on a wafer carrier, and is charged into a front chamber (not shown) of a reaction furnace 26 of the MOCVD growth apparatus. Then, the air in the front chamber is replaced with argon gas and transferred into the reaction furnace 26 in an argon atmosphere. Then, it was placed on the heater 27.

Subsequently, AsH ₃ is used by using an H ₂ carrier gas.
Thermal cleaning was performed. Then, after setting the wafer temperature to 300 ° C., which is the growth temperature, the carrier gas was switched from H ₂ to argon, and the substrate was held in an argon atmosphere to start growing the thin film. The growth conditions were a growth temperature of 300 ° C. and a growth pressure of 160 torr. The raw material supply amount was 60 μmol / min of DEZn and DTBSe.
Was set to 45 μmol / min. The p of the N-doped layer in the thin film
In the growth of the type ZnSe, the holding temperature of the bottle container 17 for the p-type dopant was set to 70 ° C., and the p-type dopant was added at a flow rate of 300 ml / min using argon as a carrier gas.

In growing a ZnSe crystal thin film, an undoped ZnSe thin film was first grown for 12 minutes on a thermally cleaned GaAs substrate. Immediately thereafter, a p-type dopant was added by a carrier gas, and an N-doped p-type ZnSe thin film was grown for a growth time of 120 minutes. After the growth was completed, the substrate temperature was lowered to room temperature. With the above growth, a 1.2 μm N-doped ZnSe thin film could be grown. As a result, Z measured by SIMS
The N concentration in the nSe thin film is 1.2 × 10 ¹⁸ cm ⁻³ ,
p-type carrier concentration (effective carrier concentration: Na-Nd,
The same applies hereinafter) to obtain a p-type ZnSe thin film of 4 × 10 ¹⁷ cm ⁻³ . From this result, it is found that the p-type Zn
The activation rate of nitrogen atoms in the Se thin film was 33%.

(Example 2) In Example 1, DEZn
Was reacted in the same manner as in Example 1 except that 10 μmol of DMZn was used instead of MeZnN (Si
A substance mainly composed of Me ₃ ) ₂ was obtained. Next, the substance is used as a p-type dopant raw material, and instead of DEZn, D
A ZnSe thin film was grown by the above MOCVD method in the same manner as in Example 1 except that MZn was used at 60 μmmol / min, and the N concentration was 1.0 × 10 ¹⁸ cm ⁻³ .
A p-type ZnSe thin film having a p-type carrier concentration of 3 × 10 ¹⁷ cm ⁻³ was obtained. From this result, p
The activation rate of nitrogen atoms in the type ZnSe thin film was 30%.

(Embodiment 3) In Embodiment 1, TMSA
The reaction was carried out in the same manner as in Example 1 except that 10 mmol of HN (SiMe ₃ ) ₂ was used instead of Z.
A substance mainly composed of tZnN (SiMe ₃ ) ₂ was obtained. In the same manner as in Example 1 except that this substance was used as a p-type dopant material, ZnSe was formed by the MOCVD method described above.
When a thin film was grown, the N concentration was 1.2 × 10 ¹⁸ c
m ⁻³ , p-type Z with p-type carrier concentration of 3 × 10 ¹⁷ cm ⁻³
An nSe thin film was obtained. From this result, the activation rate of nitrogen atoms in the p-type ZnSe thin film manufactured in Example 3 was 25%.
%Met.

(Example 4) In Example 1, TMSA
The reaction was carried out in the same manner as in Example 1 except that 5 mmol of H ₂ N (SiMe ₃ ) was used instead of Z.
A substance mainly composed of tZn) ₂ N (SiMe ₃ ) was obtained. In the same manner as in Example 1 except that this substance was used as a p-type dopant material, ZnSe was formed by the MOCVD method described above.
When the thin film was grown, the N concentration was 1 × 10 ¹⁸ cm.
^-3 , p-type carrier concentration of 2 × 10 ¹⁷ cm ^-3
An nSe thin film was obtained. From these results, it was found that the activation rate of nitrogen atoms in the p-type ZnSe thin film manufactured in Example 4 was 20%.
%Met.

(Example 5) In Example 1, TMSA
The reaction was carried out in the same manner as in Example 1 except that 10 mmol of H ₂ N (SiMe ₃ ) was used instead of Z.
A substance mainly comprising tZnNHSiMe ₃ was obtained. When a ZnSe thin film was grown by the MOCVD method in the same manner as in Example 1 except that the product was used as a p-type dopant, the N concentration was 8 × 10 ¹⁷ cm ^-3 and the p-type carrier concentration was A 1 × 10 ¹⁷ cm ⁻³ p-type ZnSe thin film was obtained. From these results, the p-type Z produced in Example 5 was used.
The activation rate of nitrogen atoms in the nSe thin film was 13%.

(Embodiment 6) FIG. 2 shows a first step of forming a p-type dopant, a second step of transporting the p-type dopant in a gas phase onto a substrate, a raw material of a group II element, and a group VI element. And the third step of vapor-phase growing a p-type II-VI compound semiconductor on a substrate by mixing the raw material and the p-type dopant with each other in the same apparatus. FIG. 1 shows a schematic view of an apparatus for forming a. In FIG.
31 is an introduction line of DEZn or DMZn (TEN), 32 is TMSAZ, HN (SiMe ₃ ) ₂ or H
Introduction line of ₂ N (SiMe _3), 33 is DTBSe the inlet line, 34 argon inlet line, 35 denotes a p-type dopant combiner, 36 and 37 gas switching valve,
46 is a reactor for growing a ZnSe thin film, 47 is a mounting table and a heater for heating the substrate, 48 is a GaAs substrate,
9 is a vacuum pump and 50 is a detoxification facility. The flow rates of the raw materials of the group II element and the group VI element are respectively controlled by a flow controller, and the pressure is reduced together with the argon carrier gas (160 t).
(or) into the reactor 46. A specific method for forming a compound semiconductor using the above apparatus will be described.

(First Step) DEZn or DMZn (T
EN) 60 μmol of DEZn through the introduction line 31
/ Min, TMSAZ, HN (SiMe ₃ ) ₂ or H ₂ N
(SiMe ₃ ) 60 TMSAZ by introduction line 32
After being introduced at a flow rate of μmol / min into the p-type dopant synthesizer 35 at 50 ° C. and normal pressure for 3 hours, respectively,
The reaction was terminated by leaving the mixture at a temperature of 1 hour for 1 hour to synthesize a p-type dopant. (Second step) Next, argon is introduced from the argon introduction line 34 by switching the gas switching valve 37,
The p-type dopant synthesized in the p-type dopant synthesizer 35 was introduced into the reaction furnace 46 in a gas phase.

(Third Step) At the same time, by switching the gas switching valve 36, DEZn or DMZn (TEN)
DEZn is introduced through the introduction line 31 at a flow rate of 60 μmol / min without passing through the p-type dopant synthesizer 35 directly into the reactor 46.
And DTBSe introduction line 33
Se was introduced into the reaction furnace 46 at a flow rate of 45 μmol / min,
The other conditions were the same as in Example 1, and the N-doped ZnSe film was grown for a growth time of 120 minutes. MO above
A p-type ZnSe thin film having an N concentration of 1.4 × 10 ¹⁸ cm ⁻³ and a p-type carrier concentration of 5 × 10 ¹⁷ cm ⁻³ was obtained by the CVD method. From this result, the activation rate of nitrogen atoms in the p-type ZnSe thin film manufactured in Example 6 was 36%. After the growth was completed, the p-type dopant synthesized in the p-type dopant synthesizer 35 was analyzed. As a result, it was found that the substance had a composition substantially the same as that obtained in Example 1.

(Example 7) In Example 6, DEZn
Was replaced with DMZn (TEN), and the flow rate in each step was 60 μmol / min, which was the same as that of DEZn, except that a thin film of ZnSe was grown by MOCVD. Concentration is 1.0 × 10 ¹⁸ cm
^-3 , p-type carrier concentration of 4 × 10 ¹⁷ cm ^-3
An nSe thin film was obtained. From this result, the activation rate of nitrogen atoms in the p-type ZnSe thin film manufactured in Example 7 was 40%.
%Met. After the growth was completed, the p-type dopant synthesized in the p-type dopant synthesizer 35 was analyzed.
A substance mainly composed of (SiMe ₃ ) ₂ , tta.

Example 8 Example 6 was the same as Example 6 except that in the first step, HN (SiMe ₃ ) ₂ was used instead of TMSAZ, and the flow rate was 60 μmol / min, which was the same as that of TMSAZ. Similarly, when a ZnSe thin film was grown by MOCVD, the N concentration was 1.0
× 10 ¹⁸ cm ^-3 and a p-type carrier concentration of 3 × 10 ¹⁷ cm
^{A -3} p-type ZnSe thin film was obtained. From these results, the activation rate of nitrogen atoms in the p-type ZnSe thin film manufactured in Example 7 was 30%. After the growth was completed, the p-type dopant synthesized in the p-type dopant synthesizer 35 was analyzed. As a result, it was found that the substance had substantially the same composition as that obtained in Example 1.

Example 9 In Example 6, H ₂ N (SiMe ₃ ) was used in place of TMSAZ in the first step, and the flow rate was 30 μmol / min. When a ZnSe thin film was grown by MOCVD, the N concentration was 1.1 × 10 ¹⁸ cm ⁻³ ,
A p-type ZnSe thin film having a p-type carrier concentration of 3 × 10 ¹⁷ cm ⁻³ was obtained. From these results, it was found that p produced in Example 8
The activation rate of nitrogen atoms in the type ZnSe thin film was 27%. After the growth was completed, the p-type dopant synthesized in the p-type dopant synthesizer 35 was analyzed. As a result, it was found that the substance had substantially the same composition as that obtained in Example 4.

(Embodiment 10) In the embodiment 1, (MO
In the step of (CVD method), TMSAZ was supplied as a raw material to the reaction furnace 26 in the same manner as in Example 1 except that the p-type dopant bottle container 17 was filled with TMSAZ.
While synthesizing nN (SiMe ₃ ) ₂ , Zn in the N-doped layer
By growing Se, Zn is grown by MOCVD.
When a Se thin film was grown, the N concentration was 1.8 × 10
A p-type ZnSe thin film having a p-type carrier concentration of ¹⁸ cm ^-3 and a p-type carrier concentration of 5 × 10 ¹⁷ cm ^-3 was obtained. From this result, it can be seen from Example 10
The activation rate of nitrogen atoms in the p-type ZnSe thin film prepared in the above was 28%.

Comparative Example 1 In Example 1, NH ₃ was replaced with p.
NH ₃ gas cylinder 14 shown in FIG.
As a result of growing an N-doped ZnSe thin film in the same manner as in Example 1 except that the concentration was introduced at 20 μmol / min, the N concentration in the thin film was 1.0 × 10 ¹⁸ cm ⁻³ , However, the p-type carrier concentration of the thin film was as low as 1 × 10 ¹⁶ cm ⁻³ and the activation rate of nitrogen atoms was as low as 1%.

Comparative Example 2 In Example 1, 6 μmol of dimethylzinc trimethylamine adduct was used as a p-type dopant and argon was used as a carrier gas.
Per minute, the p-type dopant is added at a flow rate of 500 ° C. and a growth pressure of 160 torr, and dimethyl zinc (DMM) is used as a raw material instead of DEZn.
Zn) was introduced at 60 μmol / min, and dimethyl selenium (DMSe) was introduced at 45 μmol / min in place of DTBSe, and an N-doped ZnSe semiconductor thin film was grown in the same manner as in Example 1. The concentration is 5.0 ×
At 10 ¹⁷ cm ^-3 , the p-type carrier concentration of the thin film is 1 × 10 ¹⁶
cm ^-3 and the activation rate of nitrogen atoms was as low as 2%.

In the embodiment described above, an example is shown in which the MOCVD method is used as the vapor phase growth method. However, the vapor phase growth method for carrying out the present invention is not limited to this. Method can be used. Although the example of ZnSe is given as the p-type II-VI compound semiconductor, the p-type II-VI compound semiconductor to which the present invention works effectively is not limited to this. For example, Zn _x Mg _y Be _z cd _{1-xy over z S 1-ab Te a Se} b ( where, 0 <x ≦ 1,0 ≦ y <1,0 ≦ z <1,0 <x
+ Y + z ≦ 1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1, 0 ≦ a + b ≦
1,) More specifically, ZnSSe, ZnCdSe, Z
It can be used for forming nBeSe, ZnMgSSe, ZnS or ZnTe.

[0046]

As described above, in the production of a p-type II-VI compound semiconductor thin film, according to the method of forming a p-type II-VI compound semiconductor according to the present invention, as a p-type dopant, Organic compounds having a covalent bond between a nitrogen atom and a group II element atom and between the nitrogen atom and a Si atom, particularly a covalent bond between a nitrogen atom and a group II element atom and between the nitrogen atom and a Si atom as the organic compound having the general formula (1) ~ (3) R 1 MNHSiR 2 3 ···· (1) R 1 MN (SiR 2 3) 2 ···· (2) or (R ¹ M) ₂ NSiR ² ₃ ... (3) (wherein, R ¹ represents a hydrocarbon group, preferably an aliphatic hydrocarbon group or a phenyl group having up to 4 carbon atoms, R ² is hydrogen or a hydrocarbon group, hydrogen or carbon atoms Up to 6 hydrocarbon groups, more preferably methyl groups, wherein M is zinc Indicate either magnesium or cadmium.) An organic compound represented by or the formula _{^{(4) R 1 2 Zn ·}} (NR 3 3) n ···· (4) ( provided that, R ¹ is as defined above, R ³ represents a hydrocarbon group, and n is a number of 2 or less including 0.) and bis [bis (trimethylsilyl) amide] zinc (Zn [N (SiMe ₃ ) ₂ ] ₂ ), a covalent bond between Zn and N, such as a product synthesized by reacting with bis (trimethylsilyl) amine (HN (SiMe ₃ ) ₂ or trimethylsilylamine (H ₂ N (SiMe ₃ )) In the growth of an N-doped ZnSe-based semiconductor thin film by a simple operation, the N atoms are efficiently replaced with Se lattice points, and the ratio of the number of H to the number of N in the crystal (H /
Ratio), it is possible to form a p-type II-VI compound semiconductor having a carrier concentration of 1 × 10 ¹⁷ cm ⁻³ or more, thereby producing a stable and inexpensive p-type II-VI compound semiconductor. I was able to establish a way to do it.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an MOCVD apparatus used in Examples 1 to 5, 10 and Comparative Examples 1 and 2.

FIG. 2 is a schematic view of an apparatus used in Examples 6 to 9.

[Explanation of symbols]

11 high-purity Ar gas cylinder 12 pure H ₂ gas cylinder 13 AsH ₃ bomb 14 NH ₃ bomb 15 DEZn bottle 16 p-type dopant bottle 17 DTBSe bottle 18 and 19 the carrier gas purifier 20, 21, 22 mass flow controller 25 carrier Gas switching valve 26, 46 Reactor 27, 47 Mounting table and heater 28, 48 GaAs substrate 29, 49 Vacuum pump 30, 50 Detoxification equipment 31 DEZn or DMZn (TEN) introduction line 32 TMSAZ, HN (SiMe ₃ ) ₂ or H ₂ N
(SiMe ₃ ) introduction line 33 DTBSe introduction line 34 Ar introduction line 35 p-type dopant synthesizer 36, 37 Gas switching valve

Claims (7)

[Claims] 1. A raw material of a group II element, a raw material of a group VI element and p
P-type II on the substrate by vapor phase growth using p-type dopant
In p-type group II-VI compound semiconductor forming method of growing -VI compound semiconductor thin film, as the p-type dopant, the general formula (1) ~ (3) R 1 MNHSiR 2 3 ···· (1) R ¹ MN (SiR ² ₃ ) ₂ ··· (2) or (R ¹ M) ₂ NSiR ² ₃ ··· (3) (where R ¹ is a hydrocarbon group, R ² is a hydrogen or hydrocarbon group , M represents any of zinc, magnesium and cadmium.) A method for forming a p-type II-VI group compound semiconductor, comprising using an organic compound represented by the formula: 2. In the organic compounds represented by the general formulas (1) to (3), R ¹ is an aliphatic hydrocarbon group having up to 4 carbon atoms or a phenyl group, and R ² is hydrogen or up to 6 carbon atoms. The method for forming a p-type II-VI compound semiconductor according to claim 1, wherein the compound is a hydrocarbon group. 3. The organic compound represented by any one of formulas (1) to (3), wherein R ² is a methyl group.
The method for forming a p-type II-VI compound semiconductor according to the above. Wherein general formula _{^{(4) R 1 2 Zn ·}} (NR 3 3) n ···· (4) ( provided that, R ¹ is an aliphatic hydrocarbon group or a phenyl group having up to 4 carbon atoms, R ³ represents a hydrocarbon group;
And 2 or less. ) And bis [bis (trimethylsilyl) amide] zinc (Z
n [N (SiMe ₃ ) ₂ ] ₂ ), a product synthesized by reacting with bis (trimethylsilyl) amine (HN (SiMe ₃ ) ₂ or trimethylsilylamine (H ₂ N (SiMe ₃ )) The method for forming a p-type II-VI group compound semiconductor according to claim 1, which is used as a dopant. 5. A first step of synthesizing a p-type dopant, a second step of transporting the p-type dopant in a gas phase onto a substrate, a group II element source, a group VI element source, and a p-type dopant. And the third step of vapor-growing the p-type II-VI group compound semiconductor on the substrate by mixing the p-type II-VI compound semiconductor on the substrate is performed continuously in the same apparatus. A method for forming a group VI compound semiconductor. 6. A first step of synthesizing a p-type dopant and a second step of transporting the p-type dopant in a gas phase onto a substrate in the same reaction furnace and a raw material of a group II element and bis [ Bis (trimethylsilyl) amide] zinc (Zn [N (SiM
e ₃ ) ₂ ] ₂ ), bis (trimethylsilyl) amine (H
N (SiMe ₃ ) ₂ or trimethylsilylamine (H
₂ N (SiMe ₃₎₎ at least one p-type group II-VI compound semiconductor method of forming according to claim 5, wherein the performing by mixing with either. 7. The p-type according to claim 1, wherein the p-type II-VI compound semiconductor thin film is vapor-phase grown at a growth temperature of 200 to 400 ° C. and a reaction pressure of 10 torr to normal pressure.
A method for forming a II-VI compound semiconductor.