A two-step process for selective RIE-etching of nitride on oxide in a multifacet ('HEX') plasma etching machine.
01 January 1989
A Two-Step process for the RIE etching of nitride which allows stopping in the thin pad oxide is described and analyzed. Taking into account the etch rate of nitride, oxide and photoresist, the etch rate nonuniformity and the nonuniformity of the nitride and oxide layers, the etching times can be chosen to insure three conditions: a) complete removal of all nitride b) a finite fraction of the oxide remaining and c) negligible linewidth losses.