Sputtered SiN x film for self-aligned Si-Zn diffusion into GaAs and AlGaAs

A new technology for self-aligned Si-Zn diffusion into GaAs and AlGaAs is described. In this technology, closed-tube Si diffusion is obtained from a sputtered SiNx film, and Zn diffusion self-aligned to the Si diffusion window is obtained by reusing the SiNx film as the mask. The key to a successful self-aligned Si-Zn diffusion is that the SiNx film is controlled to have a proper refractive index profile.