The deposition of silicon nitride films under low pressure on wafers up to 200 mm

Abstract

The influence of silicon nitride deposition condition on parameters of the obtained films has been investigated. It has been found that the deposition rate of silicon nitride films decreases with deposition temperature decreasing, and at the same time the within wafer thickness uniformity improves. It allows performing the reproducible deposition of silicon nitride films with thickness of less than 10 nm. It has been found that in order to decrease the oxidation depth of silicon nitride, it is appropriate to carry out the oxidation under 850–900°C. The developed process of silicon nitride deposition made it possible to obtain reservoir capacitors with specific capacitance of 3,8–3,9 fF/μm² at film thickness of 7,0 nm.