Electrical characteristics of very thin SiO2deposited at low substrate temperatures

Very thin (≲ 100-Å) films of SiO
2
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 SiO
2
in quality and may be suitable as gate dielectrics in device applications.