A low-temperature fabrication process of polycrystalline silicon-silicon p+-n junction diode

Abstract

A new method has been developed to form a p+-n polycrystalline-crystalline junction at low temperature. The technique involves the use of an e-beam evaporated polycrystalline silicon-aluminum-polycrystalline silicon multilayer structure to obtain an Al-rich polycrystalline film by heat treatment at 600°C. Experimenal evidence indicates that the current conduction is dominated by electron recombination at the interface between the polycrystalline silicon and the substrate. The best fit between a simple model and expeirmental data yields an effective recombination velocity of 5×104 cm/sec, a value consistent with carrier recombination at the grain boundaries of polycrystalline silicon.