Electrical Characteristics of Very Thin SiO₂ Deposited at Low Substrate Temperatures

Abstract

Very thin ( ≲ 100-A) films of SiO2 have been deposited by a modified plasma-enhanced chemical-vapor deposition (PECVD) process at very low substrate temperatures ( ≲ 350 °C). Low flow rates of reactive gases and a high flow of inert carrier gas were used to lower the deposition rate, ensuring improved dielectric properties and good control over film thickness. Measurements made on MOS capacitors of current-voltage characteristics, electrical breakdown, interface trap density, and mobile ion drift indicate that these very thin PECVD films are approaching thermally grown SiO2 in quality and may be suitable as gate dielectrics in device applications. Copyright © 1987 by The Institute of Electrical and Electronics Engineers, Inc.