Two-level lithographic mask for producing tapered depth

摘要

A method of producing a sloped surface in a semiconductor material. In the area where the slope is desired a dynamic mask is applied to the surface of the semiconductor. A standard mask is applied over the dynamic mask and patterned so that its edge laterally defines the bottom of the desired slope. The sample is then immersed in an etchant that etches the dynamic mask faster than the semiconductor material. The standard mask is not appreciably etched. The dynamic mask is progressively etched laterally, thereby dynamically exposing more of the semiconductor material to etchant and producing a sloped surface therein.