Development of Multiple-Step SOI DRIE Process for Superior Notch Reduction at Buried Oxide
A novel two step etch process using the Bosch-etch mechanism to prevent notching on an SOI wafer is presented. The first etch step is used to attain the maximum etch depth with high etch rate and stop before the buried oxide (BOX). Followed by the second etch step with lower etch rate and tuned to soft land on the BOX to etch the remaining depth. In addition to that it is tailored to also provide a tapered etch profile which is beneficial in reducing the notch if over etching occurs.
Lynn Khine and Julius M. Tsai
P. K. Sampath et al., "Development of Multiple-Step SOI DRIE Process for Superior Notch Reduction at Buried Oxide", Advanced Materials Research, Vol. 254, pp. 148-151, 2011