Title :
Effects of Cu diffusion on electrical properties of GaAs
Author :
Seghier, D. ; Gislason, H.P.
Author_Institution :
Sci. Inst., Iceland Univ., Reykjavik, Iceland
Abstract :
We investigated semi-insulating GaAs samples produced by Cu diffusion into n-type starting material by means of thermally stimulated current (TSC) and photoconductivity (PC) measurements, We show that the Cu-diffusion changes the EL2 centre into a deep donor (T3) with a lower activation energy, 0.7 eV. Similar effects have been observed in MBE GaAs grown at low temperature. The PC quenching and recovery of the T3 trap are similar to those usually observed for EL2. We conclude that the deep donor is a complex centre involving AsGa. In addition, we observe the usual Cu acceptor levels CuA and CuB at Ev+0.15 and Ev+0.4 eV. The dynamics of optical quenching and thermal recovery of the TSC signal from the Cu levels suggest that they are neither related to EL2 nor two levels of the same Cu-related double acceptor
Keywords :
III-V semiconductors; copper; deep levels; diffusion; gallium arsenide; impurity states; photoconductivity; thermally stimulated currents; Cu acceptor levels; Cu diffusion; Cu-related double acceptor; EL2 centre; GaAs:Cu; PC quenching; TSC; deep donor; electrical properties; low temperature; lower activation energy; n-type starting material; optical quenching; photoconductivity; recovery; semi-insulating GaAs; thermally stimulated current; Cooling; Copper; Electron traps; Gallium arsenide; Heating; Lighting; Photoconductivity; Temperature; Thermal quenching; Time measurement;
Conference_Titel :
Semiconducting and Insulating Materials, 1998. (SIMC-X) Proceedings of the 10th Conference on
Conference_Location :
Berkeley, CA
Print_ISBN :
0-7803-4354-9
DOI :
10.1109/SIM.1998.785099
