Enhancement of minority carrier lifetime in GaAs1? x P x ( x =0.4; 0.65) by nitrogen implantation

Minority carrier lifetimes in nitrogen implanted GaAs_1-x P _x (x=0.4; 0.65) were measured at 77K by an optical phase shift method as a function of nitrogen dose and annealing temperature in order to investigate the dependence of the lifetime on the concentration of nitrogen isoelectronic traps. A large increase in the lifetime was observed after nitrogen implantation followed by annealing at and above 800°C. The maximum lifetimes were 22ns for GaAs_0.35P_0.65 and 6.7 ns for GaAs_0.6P_0.4. They were obtained by implantation to a dose of 5×10¹³ cm⁻² in GaAs_0.35P_0.65 and 10¹³ cm⁻² in GaAs_0.6P_0.4. The lifetime after nitrogen implantation followed by annealing was longer by a factor of 6–7 than that of the unimplanted sample.