Role Of Ion-implantation Induced Damage And Surface States In The Response Of Gallium Arsenide Picosecond Photoconductive Switches

Abstract

We have measured the temporal response and the photocurrent-voltage characteristics of picosecond photoconductive switches fabricated on microelectronic grade GaAs. Ion-implantation induced amorphization has been used to modify the linearityof responseof theseoptoelectronic switches.The nature of the induced defects were probed by using Raman Spectroscopy and electron-beam induced electroreflectance measurements. The linearity of response is critically dependent upon the natureof the semiconductor region under the metallic contacts. The role of surface-pinned states in the response and longer lived intermediate states is examined.