<title>Diamond film polishing with argon and oxygen ion beams</title>

Abstract

In our program for ion beam polishing of microwave-assisted chemical vapor deposited diamond films using a planarizing layer we have sought to develop the technique by polishing AT-cut quartz disks used in rate monitors as an intermediate objective. Using an argon ion beam and spin-coated photoresist as the planarizing layer we successfully reduced the peak-to-valley (p-v) surface roughness from 5 pm to 0. 2 pm. In the case of diamond films whose etch rate is minute under argon bombardment reactive oxygen ions constituted the beam. The planarizing overcoat designed so that its etch rate would match that of the diamond film was a mixture of photoresist and titanium-silica. With this combination we reduced the diamond films'' surface roughness from 6 jim and 1 pm to 217 nm and 35nm p-v and mis respectively. This successful diamond film polishing opens the field of infrared optics to these materials. 1.