JPH0353516A - Vapor growth method for inp crystal - Google Patents

Abstract

PURPOSE:To vapor InP high resistance thin film crystal using a simple equipment in a stable manner by a method wherein Ti and a P-type impurity dopant are dissolved into the In of raw material. CONSTITUTION:A PCl3 gas feeding hole 4 is provided on one side of a quartz reaction tube 1, and a gas exhaust hole 6 is provided on the other side. An in source 3 is provided in the vicinity of the side of he PCl3 gas feeding hole 4 located in the quartz reaction tube 1. In this In source 3, Ti and the Zn, as a P-type impurity dopant, are dissolved. The mixture gas of PCl3 and H2 is fed into the quartz reaction tube 1. The Ti and Zn in the In source 3 become a chlorine by reacting with the PCl3 gas fed into the quartz reaction tube 1, and it is carried to the point above a crystal growing substrate 2. An InP-n<+> substrate is used as the crystal growing substrate 2, and an InP crystal layer, on which Ti and Zn are doped, is formed on the above-mentioned crystal growing substrate 2.

Description

Detailed Description of the Invention [Field of Industrial Application] This invention relates to a method for vapor phase growth of high-resistance InP-based compound semiconductor crystals, and in particular to a method for growing InP-based crystals doped with Ti and p-type impurity dopants. This relates to vapor phase growth. [Prior Art] Conventionally, a method of doping with a dopant such as Fe or Mn has been used as a method for growing a high-resistance InP-based compound semiconductor crystal. However, F
When e is used as a dopant, Fe reacts with P and F
In order to form eP2, Fe is not doped efficiently and there is a problem that a high resistance layer cannot be obtained with good reproducibility. Furthermore, when Mn is used as a dopant, Mn
There was a problem that n was thermally unstable. In order to solve such problems, Appl. Phys.
Lett. 48 (17), 28 Apri1 1
986, Ti has been conventionally used as a dopant for InP crystals, but Ti
Since high resistance cannot be obtained with i alone, p-type impurities such as Mn, Zn, and Cd are used together with Ti as a dopant. In conventional doping with Ti and p-type impurities, an organometallic compound of Ti and p-type impurities is introduced as a gas into a reaction tube, and the organometallic compound gas is thermally decomposed at high temperature to form InP.
This is a method of doping these metals into a crystalline film. [Problems addressed by the invention] However, such conventional doping methods require equipment such as piping to introduce the gas of the organic gold scrap compound, and also require adjustment of the amount of gas to be supplied. Therefore, there was a problem that the equipment became complicated and a stable high-resistance thin film crystal could not be manufactured. An object of the present invention is to provide a method for stably growing InP-based high-resistance thin film crystals in a vapor phase using simpler equipment. [Means and effects for solving the problem] I of this invention
In the vapor phase crystallization method for nP-based crystals, Ti and p-type impurity dopants are dissolved in In as a raw material. The dopant thus dissolved in In reacts with PCla gas, which is a raw material supplied into the reaction tube, to become chloride, which is transported onto the substrate and doped into a certain long crystal. The amount of dopant can be adjusted by adjusting the amount of Ti contained in the raw material In.
and p-type impurity dopant content or raw material I
This can be controlled by controlling the temperature of the n source region. In the vapor phase growth method of this invention, Ti and the p-type impurity dopant are dissolved in the raw material In, so unlike the conventional method, the organometallic compound gas that is the raw material for Dono Kunto is introduced into the reaction tube as a gas. There is no need to introduce this method, and high-resistance thin film crystals can be stably grown using simple equipment. [Embodiment] FIG. 1 is a schematic diagram showing an apparatus for explaining an embodiment of the present invention. Referring to FIG. 1, a crystal growth substrate 2 is placed inside a quartz reaction tube 1. As shown in FIG. Quartz reaction tube 1
A PC (13) gas supply port 4 is provided on one side, and a gas discharge port 5 is provided on the other side. A source 3 is provided.In this In source 3, Ti
And Zn as a p-type impurity dopant is dissolved. From P C fl3 gas supply port 4, PCI1, and H2
A mixed gas of is supplied into the quartz reaction tube 1. Tt and Zn in the In source 3 are the PCI. It reacts with s gas to become chloride and is carried onto the crystal growth substrate 2. As the crystal growth substrate 2, I
An nP-n''W plate is used, and an InP crystal layer doped with Ti and Zn is formed on this crystal growth substrate 2. After the reaction, the gas in the quartz reaction tube 1 is It is discharged from the discharge port 5. Using the apparatus shown in Fig. 1, an InP-based crystal was grown on the crystal growth substrate 2. The content is 0.05wt%, I
The temperature of the n source 3 region is 800°C, the temperature of the crystal growth substrate 2 is 600°C, the flow rate of PcL is 100 sccm, H2
Crystal growth was performed at a flow rate of 1100 seconds. As a result, a 1nP-based viscous crystal thin film having a thickness of 4 μm was formed on the crystal growth substrate 2. AuGeNi was deposited on the surface of this InP-based epitaxial crystal growth layer and on the back surface of the substrate, and the specific resistance was measured. FIG. 2 is a diagram showing the results of specific resistance measurement of this InP-based thin film. As shown in FIG. 2, the specific resistance was 1.4×10 8 Ω·Cm, confirming that the obtained InP-based crystal thin film had high resistance. In the above example, Zn was used as the p-type impurity, but the p-type impurity is not limited to Zn as long as it is a dopant that acts as a p-type impurity in the InP-based crystal, and may be, for example, Mn or Cd. etc. can be used as a dopant. [Effect of the invention] As explained above, in the vapor phase growth method of this invention, T
Since the i- and P-type impurity dopant is dissolved in the raw material In, there is no need for a conduit or the like for guiding the dopant raw material gas into the reaction tube as in the conventional method. Further, the amount of dopant can be adjusted by changing the amount of In to be contained in In, and an InP-based compound semiconductor crystal film with high resistance can be stably grown.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an apparatus for explaining one embodiment of the present invention. FIG. 2 is a diagram showing the results of measuring the specific resistance of an InP-based thin film obtained according to an embodiment of the present invention. In the figure, 1 is a quartz reaction tube, 2 is a crystal growth substrate, and 3 is a quartz reaction tube.
4 indicates an In source, 4 indicates a PCI gas supply port, and 5 indicates a gas discharge port. Figure 2 Figure fll. Ten thousand (7)

Claims (1)

[Claims] (1) In a method of growing an InP-based crystal doped with Ti and a p-type impurity dopant by a vapor phase growth method, the Ti and the p-type impurity dopant are dissolved in raw material In and doped into the InP-based crystal. A vapor phase growth method for InP-based crystals, characterized by: