Evidence for EL6 (Ecminus;thinsp;0.35 eV) acting as a dominant recombination center innhyphen;type horizontal Bridgman GaAs

摘要

Horizontal Bridgman grownnhyphen;type GaAs is shown to contain two important electron traps EL6 (0.35 eV) and EL2 (0.80 eV) in the 1015cmminus;3concentration range. A heat treatment at 800thinsp;deg;C for 1 h results in the reduction of EL6 to about 1013cmminus;3to a depth of at least 10 mgr;m and an increase in EL2 by an amount about equal to the reduction of EL6. Measurement of the minorityhyphen;carrier (hole) diffusion lengths in this depth range by an electron beam induced current (EBIC) technique shows an inverse correlation with the concentration of the EL6 trap. The results may be explained if EL6 is assumed to beVGahyphen;VAs, EL2 to be AsGahyphen;VAs, and the interaction between the two traps to involve Asi.