LONG-TERM STABILITY AT 200-DEGREES-C OF IMPLANT-ISOLATED GAAS

Highly doped n-type (n = 2 x 10(19) cm-3) and p-type (p = 7 x 10(19) c m-3) layers of GaAs were isolated by selective implantation of F+ or H + ions, followed by annealing at 500-550-degrees-C for 60 s. The resis tance of the implanted regions was measured as a function of time for long-term aging at 200-degrees-C. For both initial conductivity types and both types of implant species this resistance was stable for the d uration of the aging (approximately 1200 h). The measurement temperatu re dependence of the resistance of the implanted regions was character ized by a single activation energy in all cases, with values of 0.74 a nd 0.82 eV respectively for F+ isolation of p+ or n+ GaAs, and 0.44 an d 0.53 eV respectively for H+ isolation of p+ or n+ GaAs.