The effects of hydrogenation upon the properties of Zn-doped InP/GaAs heterostructures, which had been grown by metalorganic chemical vapor deposition, were studied by using current-voltage, deep-level transient spectroscopic, and photoluminescence methods. Significant improvements in the leakage current and breakdown voltage of InP diodes on GaAs were observed after 2h of H plasma exposure at 250C. The deep-level transient spectroscopic data revealed a corresponding reduction, in the total trap concentration, from about 6 x 1014 to about 3 x 1012/cm3; at a depth of about 1.5. The Zn dopants were completely reactivated by subsequent annealing (400C, 300s), without any degradation of the reverse current or reactivation of the deep levels. Annealing at temperatures above 580C was necessary in order to reactivate the deep levels and degrade the leakage current to their original values. It was concluded that the results indicated the passivation of threading dislocations by H, and the existence of a wide temperature window for post-passivation processing.

B.Chatterjee, S.A.Ringel, R.Sieg, R.Hoffman, I.Weinberg: Applied Physics Letters, 1994, 65[1], 58-60