Low-Temperature Chemical Vapor Deposition of SiO2 at 2-10 Torr

摘要

We discuss a new low-pressure and low-temperature process for the chemical vapor deposition (CVD) of silicon dioxide. The process differs from conventional low-pressure CVD in that lower temperatures (150-300 C) and a unique pressure window (2-10 Torr) provide the conditions for the reaction of silane (SiH4) and oxygen. In this thermal process, activation energies of 0.15=0.18 eV and deposition rates of 100 A/min at 250 C are achieved. This technique is approximately 15 times less sensitive to the O2:SiH4 ratio than atmospheric pressure CVD. The deposition conditions are compatible with both low-temperature silicon and III-V technologies. Preliminary current-voltage and capacitance-voltage measurements on silicon indicate dielectric field strength of 3,000,0000-8,000000/cm and fixed oxide charge density (Qss) less than 10 to the 11th power per sq. cm.