Interfacial and Breakdown Characteristics of MOS (Metal-Oxide-Semiconductor) Devices with Rapidly Grown Ultrathin SiO2 Gate Insulators.

摘要

Metal-oxide-semiconductor devices fabricated with tungsten/n+ polysilicon composite gate electrodes and ultrathin silicon dioxide gate insulators grown by rapid thermal growth process in a reactive oxygen ambient were characterized by various electrical measurements. The as-fabricated devices with unannealed subhundred-angstrom rapidly grown oxides exhibited breakdown characteristics superior to furnace-grown oxides as evidenced by their excellent breakdown uniformity, an average breakdown field of 15 MV/cm, and an average breakdown charge density of over 50 C/sq cm at a constant stress current density of 1 A/sq cm . The surface cleaning procedure prior to gate oxidation was observed to affect the densities of interfacial charges and surface states in the MOS structures.