REDUCTION OF RECOMBINATION CENTERS IN C-DOPED P+-GAAS/N-ALGAAS HETEROJUNCTIONS BY POSTGROWTH ANNEALING

The effect of post-growth annealing at 500, 600, and 700-degrees-C on the electrical characteristics of C-doped p + -GaAs/n-AlGaAs junction diodes fabricated with metalorganic chemical vapor deposition layers has been investigated. Recombination current is reduced by post-growth annealing at 600 and 700-degrees-C, but not at 500-degrees-C. The current reduction is primarily attributed to the dramatic reduction of 0.55 eV deep levels, which may be oxygen related complex levels. Under present annealing conditions, no degradation of carrier profiles near the p + -n junction is detected. Thus, post-growth annealing at temperatures of 600-degrees-C or higher is a promising method for reducing recombination centers in the C-doped p + -GaAs/n-AlGaAs junction.