The rf O2 plasma-induced stripping of negative photoresists from semiconductor surfaces has been detected and monitored using the optical emission from electronically excited CO product molecules at 483.5 and 519.8 nm. The active species producing the stripping has been identified as electronically excited oxygen atoms. The end point of the stripping process is easily identified as is the final cleanup of the semiconductor surface. The dependence of the stripping time as a function of flow rate and oxygen pressure has also been determined.
DegenkolbE. O.MogabC. J.GoldrickM. R., and GriffithsJ. E., Appl. Spectrosc.30, 520 (1976).
2.
DegenkolbE. O. and GriffithsJ. E., Appl. Spectrosc.31, 40 (1977).
3.
Tegal Corporation, Richmond, CA utilizes optical means to detect the end point of a photoresist stripping operation. The unit is called a Plasmaline 200 but details of the actual optical device are lacking.
4.
HarshbargerW. R.MillerT. A.NortonP. R., and PorterR. A., personal communication.
