Open tube diffusion of zinc in gallium arsenide

The diffusion of zinc in gallium arsenide has been performed under open tube conditions utilizing a zinc oxide layer as the diffusion source, silicon dioxide as an intermediate layer between the zinc oxide and the gallium arsenide, and phosphosilicate glass as a cap. The thickness of the silicon dioxide layer was used to control the amount of zinc diffused in the gallium arsenide. We have obtained a diffusion system which protects the gallium arsenide surface during the thermal cycle in a nitrogen/hydrogen flowing gas ambient. The results demonstrate the capability of reproducibly forming heavily doped p-type regions whose penetration depths were controlled from 1 to 25 µm for one to five hour-diffusions at 800°C.