Low oxygen content photoresist stripping process for low dielectric constant materials

Abstract

A plasma containing 5–10% oxygen and 90–95% of an inert gas strips photoresist from over a low-k dielectric material formed on or in a semiconductor device. The inert gas may be nitrogen, hydrogen, or a combination thereof, or it may include at least one of nitrogen, hydrogen, NH, Ar, He, and CF. The operating pressure of the plasma may range from 1 millitorr to 150 millitor. The plasma removes photoresist, the hard skin formed on photoresist during aggressive etch processes, and polymeric depositions formed during etch processes. The plasma strips photoresist at a rate sufficiently high for production use and does not appreciably attack carbon-containing low-k dielectric materials. An apparatus including a plasma tool containing a semiconductor substrate and the low oxygen-content plasma, is also provided.