Studies of ohmic contact and schottky barriers on Au-Ge/GaAs and an-Ti/GaAs
Studies of ohmic contact and schottky barriers on Au-Ge/GaAs and an-Ti/GaAs
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发表时间:
2005
影响因子:
0.5
通讯作者:
R. Ghiţă;C. Logofatu;C. Negrila;A. Manea;M. Cernea;M. Lazarescu
中科院分区:
文献类型:
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作者:
R. Ghiţă;C. Logofatu;C. Negrila;A. Manea;M. Cernea;M. Lazarescu
Gallium Arsenide (GaAs) has increasingly become an important compound-semiconductor material suited for high speed digital circuits, microwaves and detectors for high energy physics. For the fabrication of ohmic contacts on GaAs (semi-insulating- S1) wafers with characteristics as: Cr doped, (100) oriented, and ρ∼10 6 -10 7 Ωcm, has been used alloyed contact Au-Ge. The ohmic film was deposited in a high vacuum chamber (10 - 8 Torr), on a plasma etched surface of GaAs, followed by a rapid thermal annealing (RTA) at 450°C in low vacuum. For the fabrication of the rectifying contact- respectively the Schottky diode structure, we have used the same GaAs substrates. The wafers were degreased in a standard cleaning procedure, followed by a chemical etching. The Au-Ti contact has been deposited by thermal evaporation in vacuum (10 - 6 torr) followed by a RTA procedure at 300-320 °C. The carrier transport mechanisms through M/S interface are strongly influenced by the doping concentration in the semiconductor and temperature. There are presented the experimental I-V characteristics for selected samples in dark and illumination conditions. Schottky barriers height on Au-Ti/GaAs was 0.7325 V in accord with mean values on n and p type GaAs (0.5-0.8 V). The aim of this work is to fabricate a competitive X-ray detector.