Method for manufacturing semiconductor substrate

摘要

A semiconductor substrate is provided in which an alignment mark is formed that can be used for an alignment even after the formation of an impurity diffused layer by the planarization of an epitaxial film. A trench is formed in an alignment region of an N−-type layer formed on an N+-type substrate. This trench is used to leave voids after the formation of a P−-type epitaxial film on the N−-type layer. Then, the voids formed in the N−-type layer can be used as an alignment mark. Thus, such a semiconductor substrate can be used to provide an alignment in the subsequent step of manufacturing the semiconductor apparatus. Thus, the respective components constituting the semiconductor apparatus can be formed at desired positions accurately.

主权项

1. A method for manufacturing a semiconductor substrate, comprising:
preparing a substrate made of a single crystal semiconductor; forming a semiconductor layer made of a single crystal on the surface of the substrate; arranging, on the semiconductor layer, a first mask material having an opening formed in an alignment region in the semiconductor layer different from a device formation region; etching the semiconductor layer, covered by the first mask material, to form an alignment mark formation trench in the alignment region; removing the first mask material to subsequently arrange, on a surface of the semiconductor layer, a second mask material having an opening formed in the device formation region of the semiconductor layer; etching the semiconductor layer, covered by the second mask material, to form a device trench in the device formation region; removing the second mask material to subsequently bury an epitaxial film in the device trench to form voids in the alignment mark formation trench; and subjecting a part of the epitaxial film that is formed outside of the device trench to a planarization processing.