Control of Plasma Damage to Gate Oxide during High Density Plasma Chemical Vapor Deposition

Abstract

Gate oxide damage resulting from high density plasma chemical vapor deposition of silicon oxide was investigated using damage sensitive antenna structures with area ratios up to 200,000:1. Significant damage was detected from an unoptimized oxide deposition process. A 24−1 fractional factorial experimental design was used to screen the effect of four parameters: radio frequency power, microwave power, electrostatic chuck potential, and magnetic field. RF power and electrostatic chuck potential made no contribution to oxide degradation. The main factor was microwave power, and further experiments with microwave power ranging from 1500 to 2500 W showed that gate charging damage increased with microwave power, with the extent and distribution of damage depending on the magnetic field shape.