THERMIONIC EMISSION OBTAINED BY THERMAL ANNEALING IN VERTICAL POLYSILICON-MONOSILICON JUNCTIONS

This study concerns junctions obtained by the deposition of an in-situ boron-doped film of polysilicon on an N-type monosilicon substrate. T he deposition was carried out at a temperature of 560 degrees C in an industrial reactor using low-pressure chemical vapor deposition. Wafer s with a polysilicon film of 550 Angstrom and 3000 Angstrom thickness were fabricated and annealed under different conditions. To localize t he junction in the structure, the boron distribution, before and after annealing, was determined by secondary ion mass spectrometer measurem ents. Current-voltage and capacitance-voltage characteristics were mea sured and analysed to identify the dominant mechanism of conduction in such structures. The different measurements were carried out at a tem perature ranging between 299 K and 400 K.