Experimental tests of the steady-state model for oxygen reactive ion etching of silicon-containing polymers.

A steady-state model based on a silicon material balance has been proposed to predict the oxygen reactive ion etching resistance of organosilicon polymers. This model assumes that the rate limiting step is the sputtering of an SiO sub 2 film that forms on the surface of the organosilicon polymer. It predicts the etching rate of organosilicon polymers relative to the sputtering rate of SiO sub 2, based on the mass density of silicon in the polymer. The steady-state etching rate of a silyl novolac polymer is accurately predicted by the model over a wide range of etching conditions. Silyl methacrylates etch at the predicted rate under high bombardment energy conditions typical of trilevel processing, but exceed the predicted rate under low bombardment energy conditions.