Deep Levels in Semi‐Insulating LEC GaAs Before and After Silicon Implantation

Abstract

The deep trapping levels present before ion implantation of silicon into the semi‐insulating LEC starting material were investigated using optical transient current spectroscopy (OTCS). MESFET channel current deep level transient spectroscopy (DLTS) was used for the implanted material. With a silicon nitride layer used to encapsulate the for postimplantation annealing and with implantation directly into the , it was found that of seven or more deep levels seen in the semi‐insulating substrate prior to silicon implantation only the level believed to be EL12 remained. On implanting through a thin encapsulating layer and annealing under , only EL2 was found. With a silicon dioxide layer as an encapsulant, two traps remained and two apparently unreported levels appeared.