Laser crystallization of polycrystalline silicon layers on isolating substrates

Active electronic devices in crystallized polysilicon layers on insulating substrates were realized. The suitability of various lasers, layer structures, and crystallization processes, as well as the electrical characteristics of the crystallized silicon layers were examined. It is shown that only CW lasers are suitable for the production of single crystal or large-area crystalline material. Crystal sizes up to 20x30 sq micron and crystallites of over 100 micron long were produced. Patterned substrates do not bring significant advantages due to the increased processing complexity. Substrate seeding methods allow the realization of selectively located monocrystalline areas. Crystallized-layer MOS transistors show operating characteristics approaching those of transistors in monocrystalline substrate. Seeded-layer transistors show identical results to those in reference material. Therefore these layers are suitable for the production of integrated circuits.