Claims
- 1. An epitaxial wafer of gallium arsenide phosphide mixed crystal, having an improved brightness distribution, consisting of a single crystalline substrate, a gallium arsenide phosphide layer formed on the single crystal substrate having a thickness of 5-22 microns and having a mixed crystal ratio varying along a thickness thereof (hereinafter referred to as the graded layer), and a gallium arsenide phosphide layer formed on the graded layer and having a constant mixed crystal ratio along a thickness thereof (hereinafter referred to as the constant layer), wherein said epitaxial wafer comprises, in said graded layer, at least one layer region, in which the mixed crystal ratio of gallium arsenide phosphide discontinuously varies along the thickness thereof, in the range of from 2.times.10.sup.-2 to 5.times.10.sup.-2 per micron of thickness and wherein said graded layer was formed by incorporating phosphorus into said graded layer at a rate greater than 1% per micron of said graded layer.
- 2. An epitaxial wafer according to claim 1, wherein the single crystalline substrate consists of gallium arsenide.
- 3. An epitaxial wafer according to claim 1, wherein the single crystalline substrate consists of gallium phosphide.
- 4. An epitaxial wafer according to claim 1 or 2, wherein the mixed crystal ratio of the constant layer is one value in the range of from 0.35 to 0.45.
- 5. An epitaxial wafer according to claim 4, wherein said one value is 0.4.
- 6. An epitaxial wafer according to claim 4, wherein said graded layer has a thickness in the range of from 5 to 200 .mu.m.
- 7. An epitaxial wafer according to claim 4 or 6, wherein said graded layer comprises said at least one layer region on an interface between the same and the single crystalline substrate or the constant layer, in which at least one layer region the mixed crystal ratio varies discontinuously with respect to the variance of the mixed crystal ratio of said graded layer.
Priority Claims (1)
Number |
Date |
Country |
Kind |
60-133554 |
Jun 1985 |
JPX |
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Parent Case Info
This application is a continuation, of application Ser. No. 874,548, filed June 16, 1986 now abandoned.
US Referenced Citations (10)
Foreign Referenced Citations (3)
Number |
Date |
Country |
2819781 |
Nov 1978 |
DEX |
2231926 |
Jun 1981 |
DEX |
205284 |
Dec 1983 |
DDX |
Non-Patent Literature Citations (1)
Entry |
DE-Z: Siemens Forschungs-u. Entwicklungs-berichte, 3, 1974, pp. 55-60 (Huber et al.). |
Continuations (1)
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Number |
Date |
Country |
Parent |
874548 |
Jun 1986 |
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