Donor Diffusion into GaAs from Group VI Compounds

A simple and reproducible technique is presented for diffusing donors into p‐type using binary sulfides, selenides, or tellurides as donor sources. Using compound sources, the effective vapor pressure of the donor impurity is reduced, thereby limiting troublesome surface erosion of the wafers during diffusion. Either a sealed or a "closed box" system is suitable. With as a doping source, observed junction depth in zinc or in cadmium doped varied linearly with the square root of time. The diffusion coefficient of sulfur is given by in Zn doped . Anomalous results were obtained in Cd doped substrates at higher temperatures where higher values of the effective diffusion coefficients were observed.