Polysilicon etching and profile control in a CCl4–O2 plasma
- 1 March 1982
- journal article
- Published by American Vacuum Society in Journal of Vacuum Science and Technology
- Vol. 20 (3) , 476-479
- https://doi.org/10.1116/1.571339
Abstract
The etch selectivity in a CCl4–O2discharge of undoped polysilicon over SiO2 is found to increase as a function of oxygen concentration in the CCl4–O2 gas feed. Selectivities of 4:1, 15:1, and 24:1 are found at O2 concentrations of 0, 25, and 50%, respectively. Correlation of these results with observed trends in the intensities of emission bands at 465.5 nm (Cl+ 2), 288.3 nm (CO+ 2), and 278.8 nm (CCl) reflect on the differences between polysilicon and SiO2etching in fluorine and chlorine based discharges. A model for profiling an etched polysilicon line based upon the controlled erosion of photoresist is presented and shows the resultant profile to be a function of the initial photoresist profile and the polysilicon‐to‐photoresist etch selectivity. This selectivity is shown to be variable over the range from 2:1 to 1:10.Keywords
This publication has 0 references indexed in Scilit: