A STUDY ON THERMAL EMISSION OF CHARGES AT SI3N4-GAAS INTERFACES AFTERANNEALING IN N-2 AND N-2-2 MIXTURES(H)

Si3N4-GaAs interfaces subjected to annealing in N-2 + H-2 mixture or p ure N-2 atmosphere were investigated by a small-signal charge deep-lev el transient spectroscopy (Q-DLTS) method. The method measures the phy sical parameters of selective populations of the interface traps conti nuum. A dependence of the capture cross-section on activation energy w as constructed for the continuum of interface states at the Si3N4-GaAs interface. The dependence shows an exponential character in the part of the gap ranging from 0.3 to 1.0 eV below the conduction band minimu m. It was found that annealing in the temperature interval 400-450 deg rees C reduces the zero-bias band bending by about 0.1 eV. At temperat ures of 500 degrees C and more, degradation of the interface started; compared with annealing in pure N-2 ambient, annealing in an N-2 + H-2 mixture degraded the interface slightly more.