Defects in Low-Temperature-Grown MBE GaAs as Studied by a Variation of TSC Spectroscopy
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DEFECTS IN LOW-TEMPERATURE-GROWN MBE GaAs AS STUDIED BY A VARIATION OF TSC SPECTROSCOPY
Z-Q FANG AND D.C.LOOK Physics Department, Wright State University, Dayton,
OH 45435
ABSTRACT A zero-bias thermally stimulated current (TSC) spectroscopy under both optical (1.96eV) and electrical excitation using samples with a Schottky contact on the top was applied to annealed LTnBE GaAs grown at different temperatures, and bulk SI GaAs with different stoichiometries. The results show that: 1) the new TSC technique is capable of revealing the traps at 235K300K in both samples are dominated by an activation energy of about 0.78eV; 2) the Idark'S in annealed LTMBE GaAs are closely related to the growth temperature, i.e. for higher TG, Idark is lower (note that Idark for the 200°C LTMBE sample was obtained after the sample cleaved during the rapid cooling cycle); 3) as compared to the non-annealed control sample (NCS), the
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Fig.4 & 5 Comparison of regular TSC and ZBTSC (E & 0) for two control samples annealed control sample (ACS) shows lower Idark, especially in the temperature induced by range 140K
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