Charles A. Whiting

Etch characteristics of various materials in ethanolamine etchants

Abstract Data for the etch rates of passivating and non-passivating films are presented for the anisotropic etchant ethanolamine-gallic acid-water. Thesedataidentifyusefulmasking and conductive layers for

Development of a membrane-etch wet station for x-ray masks

This paper describes the evolution of a simple recirculating etch station into a successful x-ray mask membrane-etch station. The manufacturing etch station consists of a large, heated mix tank in which she ethanolamine solution is brought to reaction temperature. The etchant is then pumped into a smaller heated process tank and is continuously recirculated through a filter between the two tanks. Up to 50 substrates can be processed during one product run. Both tanks and wetted parts are made of Teflon. Salient features of the membrane-etch station include dual Pyrex reflux columns, a nitrogen blanket throughout the systems to prevent oxygen infiltration, special high-temperature Teflon and Gore-tex seals for the mix and process tank lids, and a Teflon filter in the recirculating line between the mix and process tanks. Subsequent tooling improvements included improving the thermal sensors and installing more powerful heaters. Tool qualification tests have demonstrated the membrane-etch station ready for manufacturing use. The manufacturing etch station has increased our etch capacity by almost an order of magnitude and is currently being used to produce silicon membranes for x-ray mask substrates.