NEAR-INFRARED TRANSMISSION MEASUREMENT OF EL2 CONCENTRATION IN SEMIINSULATING GAAS WAFERS WITH A LASER DIODE (LAMBDA=1.3-MU-M)

Abstract

We demonstrated a near-infrared transmittance setup for EL2 concentration mapping in undoped semi-insulating (SI) GaAs wafers. The light source was a power-stabilized laser diode (lambda = 1.3-mu-m) operating in the light emitting diode (LED) mode. The sensitivity of the apparatus was as low as 10(14) cm-3 for typical commerical wafers 350-mu-m in thickness.