Resonance tunnel device

摘要

The method for forming a semiconductor microstructure of this invention includes the steps of: forming a mask pattern having a first opening and a second opening on a substrate having a semiconductor layer as an upper portion thereof; and selectively etching the semiconductor layer using the mask pattern to form a semiconductor microstructure extending in a first direction parallel to a surface of the substrate, wherein, in the step of selectively etching the semiconductor layer, an etching rate in a second direction vertical to the first direction and parallel to the surface of the substrate is substantially zero with respect to an etching rate in the first direction, and a width of the semiconductor microstructure is substantially equal to a shortest distance between the first opening and the second opening in the second direction.