Integrated self aligned contact etch

摘要

An integrated self aligned contact process includes oxide etch with high oxide etch rate, integrated selective oxide etch and nitride liner removal with high selectivity to corner nitride with the ability to remove the bottom nitride liner, and stripping of all polymer and photoresist. C4F8 and CH2F2 are used for the high selectivity oxide etch step. The unique behavior of CH2F2 in high density plasma allows polymer protection to form on the nitride corner/sidewall while at the same time etching the bottom nitride.