1988 Fiscal Year Final Research Report Summary
STUDIES ON SURFACE-BARRIER DIODE OF II-IV COMPOUND SEMICONDUCTOR
| Project/Area Number |
62550012
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Applied materials
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| Research Institution | NAGOYA INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
SAJI Manabu NAGOYA INSTITUTE OF TECHNOLOGY, 工学部, 教授 (50024211)
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| Co-Investigator(Kenkyū-buntansha) |
YASUDA Kazuhito NAGOYA INSTITUTE OF TECHNOLOGY, 工学部, 講師 (60182333)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Crystal Growth of CdTe / MOCVD / Surface Analysis by AES and ESCA / CdTeの表面安定化 |
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| Research Abstract |
II-VI compound semiconductors are very interested materials in a high sensitive infrared detector, a blue light emitted diode and a high efficient solar cell. It is needed high quality single crystals and devicetechnology inclused in surface stabilized techniques.
(1) Modified surface layers of CdTe single crystals were investigated by auger electron spectroscopy(AES) and X-ray photo-electron spectroscopy(XPS). On a surface etched by Br-methanol, there is the good surface condition with modified layer less than lnm. On the surface etched thermal process at 450 C in H2 gas flow after chemical etching, there is the chemical stabilized surface condition at stoichiometric without oxicided layer.
(2) A low pressure metal-organic chemical vapor deposition(MOCVD) equipment was build up for purpose of high quality CdTe thin film crystal growth.
The epitaxial layers were grown on (100), (111)A and (111)B CdTe substrates and (100)GaAs by MOCVD, where metal organics used were DMCd and DETe.
The crystal growth experiments were carried out in the H2 gas at 60 torr, varying the growth parameters such as growth temperature range of 350 C-480 C and Te:Cd ratio from 1 to 10. Below the temperature of 400 C, the growth rate is not depended on Te:Cd ratio but depended on pyrolytic amount of Cd adduct. Above the temperature of 400 C, the growth rate become to depend on the substrate temperature and dete flow rate. The groeth mechanism is emplained by Langmuir-Hinshelwood model controlled by the surface reaction of Cd and Te.
On the dependency of substrate orientation, (100) epitaxial layer is better than (111)layer at surface morphology and crystal quality by means of SE,, PL and X-ray locking curve.
It was found a growth condition that the CdTe(100) layer was always grown on GaAs(100)substrate. This epitaxial layer over the 2 m thickness was shown to be p-type.
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