Dry Etching of Glass Using Excimer Laser Irradiation in the Presence of Select FREON Gases
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18
The excimer laser process disclosed uses ultraviolet radiation to photo-chemically dissociate certain FREON* gases. Reactive transient species are produced which diffuse to the glass surface where, in conjunction with residual ultraviolet photons, the etching process occurs. FREON gas CF2Br2 is used to etch the glass. KrF (248 nm) excimer laser pulses illuminate a mask which is subsequently imaged onto the glass surface by a known lens projection technique. CF2Br2 interacts strongly with KrF laser radiation and, when illuminated, exhibits intense fluorescence. The single pulse etch rate is dependent upon the laser pulse fluence and pressure of the gas. Photo-dissociation of the gaseous FREON molecule produces reactive radical fragments.