JPS616200A - Process for doping crystal of gaas, inas, or the like with si - Google Patents

Abstract

PURPOSE:To obtain uniform crystal having only slight concn. difference in the crystal without entanglement of oxygen in the stage of synthesizing crystal of GaAs or InAs, or a crystal based thereon, or in the stage of growing single crystal by adding a necessary amt. of previously prepd. SiAs and regulating the degree of doping optionally. CONSTITUTION:For example, when GaAs is synthesized, Ga and As are charged in a crucible made of BN, etc., and B2O3 is placed thereon, and the synthesis is carried out by heating in the stream of N2, etc. under pressure. In this invention, calculated amt. of Si is added in the form of SiAs in addn. to Ga and As and heated. In this case, since the m.p. of SiAs is 11 deg.C which is lower than the m.p. of GaAs, i.e. 1,248 deg.C, SiAs becomes liquid and is easily reactive with GaAs, and is easily miscible and uniformized. Therefore, a regulated amt. of Si can be doped in the crystal of GaAs, InAs, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for doping GaAs, InAs or crystals based thereon with a defined amount of Si.

When GaAs and InAs were conventionally synthesized in a quartz glass boat, 5i02 reacted with Ga or In, and Si
O□ is reduced to Sl, which is the synthesized GaA
Ga1ls and InAs with low resistance were synthesized in the same way as when Sl was mixed into S and InAs and S1 was doped. However, in this case, the amount of Si mixed in is not regulated, and the amount of S mixed in varies greatly depending on the synthesis time, temperature, surface condition of the boat, etc. In addition to Si, oxygen is also mixed in at the same time, causing S in the crystal to
The i concentration also varied depending on the location and was not constant. The purpose of the present invention is to create a homogeneous crystal in which the doping amount of Sl can be arbitrarily specified, there is no mixing of oxygen, and there is little difference in the concentration of Si in the crystal. 3 for crystals such as GaAs and !nAs.
1 is to provide a method of doping.

When synthesizing GaAs, according to the direct synthesis method, Ga and As are
is placed in a BN crucible or quartz crucible, 8203 is placed on top, and the mixture is heated and synthesized under a pressurized nitrogen or argon stream. In the method of the invention, a calculated amount of Sl in the form of SiAs is added and heated. In this case, in the length where Si is simply added, the melting point of Sl is 140.
Since it is above 0°C, it melts, and since S] has a light specific gravity of 2.3, it floats on top of Ga and only a portion of it mixes with GaAs. The amount of mixture also varies depending on conditions such as Si particle size and temperature. According to the method of the present invention, since SiAs has a melting point of 11'c, which is lower than the melting point of GaAs of 1248'c, SiAs becomes liquid and is mixed with GaAs. It is easy to react and mix uniformly. GaAs and 1nAs are also arsenic compounds and have good affinity, so it is thought that all of the added SiAs will be mixed, and no oxygen will be mixed in. Therefore, if a container such as a BN crucible is used. If there is no contamination from Si, it is possible to ink the current amount of Si into crystals of GaAs, 1nAs, etc. by the method of the present invention.

Example 1 In GaAs synthesis by direct synthesis method, Ga 1.000
g, 1.5 g of SiAs was added to 1,096 g of As, 350 g of B2O was added, and the GaAs was heated under 80 atm of nitrogen.
was synthesized. After the synthesis, the nitrogen pressure was lowered to 20 atm and the single crystal was pulled off, yielding 235 g of 1) crystal. This single crystal had a resistivity of 1.8 x 1039 cm. From measurements of the wafer, carrier 1 degree 2X10''/cd, electron mobility u-1, 800cat/Vsec were obtained.

Example 2 SiAs was added to 1.4 kg of non-doped GaAs polycrystal.
Add Og, add 820350g, 4kg/cn+
was melted under a nitrogen atmosphere. After melting, the pressure is 3kg/c.
++l and pulled the single crystal to a diameter of 48 to 52 m/
658 g of a single crystal of m was obtained. The specific resistance of this single crystal is 1.
It was 7103 Ωcm.

Claims (1)

[Claims] A method for doping Si into a crystal such as GaAs, InAs, etc., which comprises adding a necessary amount of previously prepared SiAs when synthesizing GaAs, InAs or a crystal based thereon or growing a single crystal thereof.