MICROSTRUCTURING OF AS40S60 WAFERS EXPOSED TO SOFT X-RAYS

The possibilities of 'resistless' microstructuring of As36.1S63.9 wafe rs by soft X-ray irradiation and wet alkaline etching have been invest igated. Scanning electron microscopy is used to study the influence of the exposure and processing parameters on the depth and acuity of the patterned structures. Structures 1 mu m wide are obtained by irradiat ion with an energy flux of 2000 mJ cm(-2), followed by etching in a so lution of pH 10.8 at a temperature of 23 degrees C for a processing ti me of 18 min. It is established that by X-ray irradiation and suitable processing of As36.1S63.9 wafers, microstructures of a depth up to 0. 65 mu m could be patterned. The structured wafers could be used as dif fraction elements for IR optics. (C) 1998 John Wiley & Sons, Ltd.