Crystal film epitaxy on amorphous or polycrystalline substrate - by imprinting periodic structure on substrate before crystal growth

摘要

In a crystal growth process for the epitaxy of a film of a crystal system on an amorphous or polycrystalline substrate, a periodic plane structure with the symmetry of the system to be crystallised is imprinted on the substrate before crystallisation. This periodic structure pref. has a lattice constant which is an integral multiple of the system to be crystallised. It can be produced by scanning with an electron beam; by ion implantation, using a crystal with a channel structure as mask; by ion implantation, using a crystal with a layered structure, pref. with rotation of the mask through a given angle to give a line lattice; or by interference of electromagnetic or electron radiation. The process can be used in the prodn. of semiconductor elements. The process ensures that the film is monocrystalline and is suitable for growth from soln., from the gas phase or for vacuum vapour epitaxy. It avoids the need to use very costly substrate crystals, e.g. sapphire or spinel. The process could also be used for the mass prodn. of cheap solar cells.