METHOD FOR FABRICATING SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for fabricating a semiconductor device is provided to accurately stop etching in a hetero-junction boundary when a hetero-junction structure is selectively etched by selectively eliminating an AlyGa1-yAs layer when light is irradiated. CONSTITUTION: The second semiconductor layer having a band gap smaller than that of the first semiconductor layer is disposed on the first semiconductor layer in a hetero-junction structure, wherein the energy of the valence band of the second semiconductor layer is larger than that of the first semiconductor layer. A metal layer is formed in the outside of the first portion from which the second semiconductor layer is removed. The metal layer is covered with a mask pattern exposing the first portion of the second semiconductor layer. A light irradiation process is performed to selectively remove the second semiconductor layer by using the mask pattern as a mask and etchant having a Fermi level higher than that of the second semiconductor layer.