Epitaxial crystal growth onto a stabilizing layer which prevents diffusion from the substrate

Claim 1

AN IMPROVEMENT IN THE PROCESS FOR EPITAXIAL CRYSTAL GROWTH WHEREIN A SOLID EPITAXIAL LAYER OF MONOCRYSTALLINE STRUCTURE IS GROWN UPON A DOPED CRYSTAL SUBSTRATE AT AN ELEVATED TEMPERATURE BY NUCLEATION OF A SEMICONDUCTOR MATERIAL FROM THE GASEOUS PHASE UPON A MONOCRYSTALLINE SURFACE OF THE CRYSTAL SUBSTRATE FOLLOWED BY CONTINUED GROWTH OF SAID EPITAXIAL LAYER BY THE DEPOSITION OF ADDITIONAL SEMICONDUCTOR MATERIAL FROM THE GASEOUS PHASE UPON THE EXPOSED SURFACE OF THE GROWING EPITAXIAL LAYER THE IMPROVEMENT IN COMBINATION THEREWITH COMPRISING EPITAXIALLY GROWING A STABLIZING MONOCRYSTALLINE LAYER ON SAID SUBSTRATE AT SAID ELEVATED TEMPERATURE, THEREAFTER LOWERING THE TEMPERATURE OF THE CRYSTAL GROWTH SURFACE OF THE SAID STABILIZING LAYER TO A TEMPERATURE ABOVE THE POLYCRYSTALLINE FORMATION TEMPERATURE OF SAID SEMICONDUCTOR MATERIAL, AND CONTINUING THE GROWTH PROCESS OF SAID LAYER AT THE LOWER TEMPERATURE.