ION BEAM MIXING IN AMORPHOUS SILICON - 1. EXPERIMENTAL INVESTIGATION.

Atomic mixing in amorphous Si has been investigated by measuring the irradiation-induced spreading of very thin impurity layers embedded in vacuum-deposited Si as a function of ion species, dose, implantation temperature and impurity species. Samples consisting of approximately 10 A layers of Ni, Ge, Pd, Sn, Sb, Pt and Au at depths of 200-600 A were irradiated at temperatures from 77 to 523 K with 50-300 kev Ne** plus , Ar** plus , Kr** plus and Xe** plus ions to doses of about 10**1**4-10**1**7 ions cm** minus **2 and analyzed by 1. 5 Mev He** plus ion backscattering spectrometry. The morphologies of the samples before and after irradiation were examined by transmission and scanning electron microscopy. The effective diffusion lengths squared, Dt, were deduced from the increases in the variances of the backscattering signals from the impurity species.