Improved NMP Strip of Photoresist After CF4 + H2 RIE Etch
Original Publication Date: 1985-Feb-01
Included in the Prior Art Database: 2005-Feb-18
A technique for improving the N-methyl-2-pyrrolidine (NMP) stripping of photoresist subsequent to a CF4 + H2 reactive ion etch (RIE) step consists of removing approximately 2000 ˜ of photoresist "skin" with a RIE O2 or plasma O2 prior to NMP application. This technique permits NMP photoresist stripping to occur without removing the underlying Si, SiO2 or Si3N4 layers. NMP stripping can be carried out on wafers having filled isolation trenches. When carrying out the above-described skin removal step prior to NMP strip, a concern is that the insulator material within these trenches could be at least partially removed, adversely affecting device planarity.