Dry etch improvements in the SOI Wafer Flow Process for IPL stencil mask fabrication

The 4x Ion Projection Lithography (IPL), which is designed to reach sub 100nm resolution on the wafer plane, uses stencil membrane masks out of 150mm SOI (Silicon On Insulator) wafers [1]. The structured circular membranes have a diameter of 126mm and a thickness of 3 mu m. Results of a new sub-quarter micron trench etch and membrane dry etch process are presented and discussed.