The self-aligned diffusion of Zn was studied. It was found that the use of a Si film for the diffusion led to major problems of morphology degradation and dopant contamination during Si diffusion. A method which involved both a SiO2 encapsulant and a sputtered Si film source (Si diffusion) or mask (Zn diffusion) was investigated. The optimum thicknesses of the Si and SiO2 films were 18 and 55nm, respectively.

W.X.Zou, S.Corzine, G.A.Vawter, J.L.Merz, L.A.Coldren, E.L.Hu: Journal of Applied Physics, 1988, 64[4], 1855-8