The effect of varying the NH3 flux, upon the concentrations of background Si, free carriers, and deep traps for majority and minority carriers in n-type layers that had been grown by vapor phase epitaxy, was studied by means of secondary ion mass spectrometry and deep-level transient spectroscopy. The contribution which background Si made to the free carrier concentration in samples which were doped with N was considered. It was shown that a deep center at Ec - 0.24eV could be attributed to Si. A center of the form, SiGa-VP, could account for the present experimental results. The concentration of the predominant non-radiative recombination center at Ev + 0.75eV was studied as a function of the growth conditions, and a model for it was proposed which was in the form of a complex that consisted of intrinsic defects.

A.V.Skazochkin, J.K.Krutogolov, G.G.Bondarenko: Semiconductor Science and Technology, 1996, 11[4], 495-501