EVIDENCE OF A THERMALLY STABLE CARBON-NITROGEN DEEP-LEVEL IN CARBON-DOPED, NITROGEN-IMPLANTED, GAAS AND ALGAAS

Nitrogen ion implantation is shown to form high resistivity regions (rho(s) greater than or equal to 1 x 10(10) Ohm/square) in C-doped GaAs and Al0.35Ga0.65As that remains compensated after a 900 degrees C anneal. This is in contrast to oxygen or fluorine implantation in C-doped GaAs which both recover the initial conductivity after a sufficiently high temperature anneal (800 degrees C for F and 900 degrees C for 0). In C-doped Al0.35Ga0.65As N- and O-implant isolation is thermally stable but F-implanted samples regain the initial conductivity after a 700 degrees C anneal. A dose dependence is observed for the formation of thermally stable N-implant compensation for both the GaAs and AlGaAs samples. A C-N complex is suggested as the source of the compensating defect level for the N-implanted samples. Sheet resistance data vs anneal temperature and estimates of the depth of the defect levels are reported. This result will have application to heterojunction bipolar transistors and complementary heterostructure field effect transistor technologies that employ C-doped AlGaAs or GaAs layers along with high temperature post-implant isolation processing.