JP2002009001A - Compound semiconductor epitaxial wafer and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compound semiconductor epitaxial wafer which is uniform in distribution of carrier concentration through its surface, with a film formed on its surface kept uniform in thickness and composition distribution through the surface, and to provide a method of manufacturing the same. SOLUTION: When an N-type conductive layer 2 is grown on a semiconductor substrate 1 through an MOVPE method, a mixture of Si2H6 and H2Se as N-type dopant is fed to enable Si and Se to reside in the N-type conductive layer. Si2H6 and H2Se as N-type dopant are different from each other in doping efficiency at growth temperatures, so that Si2H6 and H2Se indicate the opposed doping distributions to a temperature distribution through the surface of the wafer 1. Therefore, Si2H6 and H2Se are supplied at the same time, by which a temperature distribution is canceled through the surface of the wafer, and a carrier concentration gets uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compound semiconductor epitaxial wafer such as a wafer for a field effect transistor, a wafer for a hetero bipolar transistor, and a wafer for an optical device, and a method for manufacturing the same. The present invention relates to a compound semiconductor epitaxial wafer having a uniform carrier concentration in-plane distribution while maintaining uniform distribution, and a method for manufacturing the same.

[0002]

2. Description of the Related Art A conventional compound semiconductor epitaxial wafer is formed on a semi-insulating GaAs substrate by metal organic chemical vapor deposition (M.P.M.).
When one or more epitaxial wafers are grown by the metal organic vapor phase epitaxy (OVPE) method, one kind of dopant material is supplied as a dopant material for the n-type conductive layer.

[0003]

However, according to the conventional compound semiconductor epitaxial wafer, only one kind of dopant material is used as the dopant material for the n-type conductive layer, so that the growth conditions (growth rate, growth temperature, group III material, Group V raw material,
(E.g., growth pressure), the carrier concentration distribution in the wafer surface may be deteriorated. On the other hand, when the growth conditions are changed to improve the in-plane distribution of the carrier concentration, the film thickness distribution and the composition distribution whose in-plane distribution is uniform under the conditions may be deteriorated.

Accordingly, an object of the present invention is to provide a compound semiconductor epitaxial wafer having a uniform in-plane distribution of the carrier concentration while maintaining the uniformity of the in-plane distribution of the film thickness and the composition, and a method of manufacturing the same. .

[0005]

In order to achieve the above object, the present invention provides a compound semiconductor in which an n-type conductive layer is grown on a III-V compound semiconductor substrate by metal organic chemical vapor deposition (MOVPE). In the epitaxial wafer, the n-type conductive layer provides a compound semiconductor epitaxial wafer, wherein Si and Se are present in at least one layer. According to the above configuration, when growing the n-type conductive layer, Si ₂ H ₆ and H ₂ Se are supplied as n-type dopants, so that S
i and Se can be present. Since the doping efficiencies of the n-type dopants Si ₂ H ₆ and H ₂ Se are different from each other with respect to the growth temperature, the doping distributions are opposite to the temperature distribution in the wafer surface. Therefore, Si ₂ H ₆
By simultaneously supplying H ₂ Se and H ₂ Se, the in-plane temperature distribution is canceled and the carrier concentration distribution becomes uniform.

[0006] In order to achieve the above object, the present invention provides
Metalorganic vapor phase epitaxy (MOV) on -V compound semiconductor substrates
In the method of manufacturing a compound semiconductor epitaxial wafer for growing an n-type conductive layer by a PE) method, the n-type conductive layer is grown by supplying Si ₂ H ₆ and H ₂ Se as n-type dopants. Provided is a method for manufacturing a compound semiconductor epitaxial wafer, characterized in that Si and Se are present in a conductive layer.

[0007]

FIG. 1 shows a compound semiconductor epitaxial wafer according to an embodiment of the present invention. This compound semiconductor epitaxial wafer has a plane orientation of 2 ° OFF.
On a (100) semi-insulating GaAs (gallium arsenide) substrate 1, Si ₂ H ₆ (disilane) and H ₂ Se (hydrogen selenide) are simultaneously supplied as doping materials by MOVPE to provide n-type conductivity. Composition 3 as conductive layer
It is obtained by growing 0% AlGaAs (aluminum gallium arsenide) 2. The abundance ratio of Si and Se in the n-type conductive layer is preferably 0.1 ≦ ([Si] / [Se]) ≦ 10.

The n-type conductive layer is made of G
aAs (gallium arsenide), InGaAs (indium gallium arsenide), InAlAs (indium aluminum arsenide), InGaP (indium gallium phosphide), AlG
aInP (aluminum gallium indium phosphide), Ga
P (gallium phosphorus) and AlInP (aluminum indium phosphorus) can be used.

Next, a method of manufacturing the above compound semiconductor epitaxial wafer will be described. Here, Ga
TMG (trimethylgallium) as a raw material of (III), TMA (trimethylaluminum) as a raw material of Al (III), and AsH as a raw material of As (V)
_{3 Use} (arsine). First, the GaAs substrate 1 is placed on a susceptor in a reaction tube (not shown), and the susceptor is heated by a high-frequency coil to warm the GaAs substrate 1. next,
TMG, TMA and AsH ₃ gas are supplied to the reaction tube, and Si ₂ H _{6 as a} dopant gas is contained in these gases.
And H ₂ Se at the same time, and doping Si and Se in the gas while growing the GaAs substrate 1 at 700 ° C.
An AlGaAs layer 2 is grown thereon.

FIGS. 2 to 4 show A of the epitaxial wafer.
The lGaAs carrier concentration in-plane distribution is a result obtained by C-V measurements, Si ₂ H ₆ 2 as doping material
And H ₂ illustrates the present embodiment using the Se, Comparison of Figure 3 shows a comparative example 1 when using Si ₂ H ₆ as a doping material, 4 with H ₂ Se as doping material Example 2 will be described.

Comparing the carrier concentration distributions, in Comparative Example 1 shown in FIG. 3 and Comparative Example 2 shown in FIG. 4, the distributions are upwardly convex and downwardly convex, respectively. Therefore, by simultaneously supplying two types of doping materials of Si ₂ H ₆ and H ₂ Se, an AlGaAs layer 2 having a uniform in-plane carrier concentration distribution can be obtained as shown in FIG.

It is to be noted that the present invention is directed to a method of manufacturing an epitaxial wafer having a uniform in-plane carrier concentration distribution in the p-type conductive layer as well as in the n-type conductive layer, provided that there are two kinds of optimum dopants. Becomes possible.

[0013]

As described above, according to the compound semiconductor epitaxial wafer and the method of manufacturing the same of the present invention, when growing an n-type conductive layer, Si ₂ H ₆ and H ₂ Se are used as n-type dopants. Since Si and Se are present in the n-type conductive layer by supply, there is no need to change the growth conditions, and the film thickness distribution and composition distribution uniformity do not need to be changed.
The carrier concentration distribution can be made uniform while maintaining the properties.
Thereby, an epitaxial wafer for a field-effect transistor, an epitaxial wafer for a hetero-bipolar transistor, an epitaxial wafer for an optical element, and the like having a uniform in-plane distribution can be manufactured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a compound semiconductor epitaxial wafer according to an embodiment of the present invention.

FIG. 2 shows a carrier concentration in-plane distribution of a compound semiconductor epitaxial wafer according to an embodiment of the present invention.

FIG. 3 is an in-plane carrier concentration distribution of an AlGaAs single-layer epitaxial wafer grown by doping with Si ₂ H _{6 according} to Comparative Example 1.

FIG. 4 shows a carrier concentration distribution in an AlGaAs single-layer epitaxial wafer grown by doping with H ₂ Se according to Comparative Example 2.

[Explanation of symbols]

 1 GaAs substrate 2 AlGaAs layer

 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference) 4G077 AA03 BE43 BE46 BE47 DB08 EB01 HA06 TJ06 4K030 AA11 BA02 BA08 BA11 BA25 BA51 BB02 CA04 FA10 JA06 LA15 5F045 AA04 AB10 AB11 AB17 AB18 AC01 AC08 AC19 AD10 AD11 AF04 AF13 BB02 BB59 EK02 5F103 AA10 DD03 DD05 DD07 DD08 HH03 JJ03 KK01 KK10 LL01 LL07 LL11 NN06 RR04

Claims (4)

[Claims] 1. A compound semiconductor epitaxial wafer in which an n-type conductive layer is grown on a group III-V compound semiconductor substrate by metal organic chemical vapor deposition (MOVPE), wherein the n-type conductive layer has at least one layer. Si and Se
A compound semiconductor epitaxial wafer characterized by the presence of: 2. The method according to claim 1, wherein the n-type conductive layer is formed of GaAs, AlGa.
As, InGaAs, InAlAs, InGaP, Al
Any one of GaInP, GaP and AlInP
2. The compound semiconductor epitaxial wafer according to claim 1, wherein the compound semiconductor epitaxial wafer has a single-layer structure. 3. The method according to claim 1, wherein the content ratio of Si and Se is 0.1 ≦
2. The compound semiconductor epitaxial wafer according to claim 1, wherein ([Si] / [Se]) ≦ 10. 4. A method of manufacturing a compound semiconductor epitaxial wafer for growing an n-type conductive layer on a III-V group compound semiconductor substrate by a metal organic chemical vapor deposition (MOVPE) method, wherein the n-type conductive layer is grown. , Si as an n-type dopant
₂ H ₆ and H ₂ Se are supplied to form S in the n-type conductive layer.
A method for producing a compound semiconductor epitaxial wafer, wherein i and Se are present.