Interfacial and breakdown characteristics of MOS devices with rapidly grown ultrathin SiO2gate insulators

Metal-oxide-semiconductor (MOS) devices fabricated with composite gates and subhundred-angstrom SiO2gate insulators grown by rapid thermal oxidation were characterized by various electrical measurements. The as-fabricated devices with unannealed 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/cm2at a stress current density of 1 A/cm2. The preoxidation surface cleaning procedure was observed to affect the charge-to-breakdown and the densities of fixed oxide charges and surface states in these MOS structures.