A Challenge to the limit of Low Growth Temperature of LEP GaAs

1998 Fiscal Year Final Research Report Summary

• Project/Area Number: 09650343
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Electronic materials/Electric materials
• Research Institution: FOUNDATION FOR ADVANCEMENT OF INTERNATIONAL SCIENCE
• Principal Investigator: NANNICHI yasuo Research Dept. MTS, 研究開発部, 専任研究員 (10133026)
• Co-Investigator(Kenkyū-buntansha): OOIGAWA Haruhiro UNIV. of Tsukuba INST. of applied Physics, Lecturer, 物理工学系, 講師 (60223715)
• Project Period (FY): 1997 – 1998
• Keywords: GaAs / Limit of low defect density / Crystal growth / Sulfur treatment / Temp. Difference LPE / 低結晶成長温度

Research Abstract

IT IS KNOWN THAT T}IE STRUCTURAL DEFECT DENSITY, NAMELY VACAINCIES/INTERSTITIALS DENSITIES, SHOULD BE MINIMAL IN GaAs CRYSTALS GROWN BY LIQUID PHASE EPITAXY AT CERTAIN REGIONS OF Low TEMPERATURE. HOWEVER, No ONE HAS EVER CHALLENGED T'HIS DIFFICULT TASK.
HERE WE CHALLENGED. THE KNACK IS TO USE 1) TEMPERATURE DIFFERENCE LIQUID PHASE EPITAXY, IN WHICH THE SOURCE MATERIAL IS KEPT AT A HIGHER TEMPERATURE THAT SUBSTRATE TEMPERATURE, AND 2) To PREPARE 11 A PRESTINE SURPACE BY TREATING WITH POLY=AMMONIUM SULFIDE. THUS TREATED SRFACE WAS EXTENSIVELY STUDIED BY US To BE COVERED WITH A MONO-LAYER OF SLTLFUR, WHTCH KEEPS OXYGEN FROM ADSORBING ON GaAs SURFACE.
SO FAR WE OVSERVED GaAs CRYSTALS TO C.ROW AS LOW AS 214℃, THAT IS THE LOWEST CROWTH TEMPERATURE POR GaAs. HOWEVER, THE SIZE OF THE CRYSTAL Is TOO TINY, ON THE ORDER OP A FEW HUNDRED MICRONS. TO MEASURE ITS CHARACTERISTICS. WE BELIEVE UNDER ULTRA HIGH VACUUM CONDITION. THE STZE PROBLEM COULD BE SOLVED.