MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE AND SEMICONDUCTOR DEVICE

摘要

The characteristics of a semiconductor device using a nitride semiconductor are improved.;A trench which penetrates an insulating film and a barrier layer and reaches inside of a channel layer is formed by etching the channel layer, the barrier layer, and the insulating film which are formed over a substrate. Then, an epitaxial regrowth layer is formed over a bottom surface and a side surface of the trench by using an epitaxial growth method. It is possible to reduce roughness (unevenness) of a crystal surface due to etching and the like of the bottom surface and the side surface of the trench by forming the epitaxial regrowth layer in this way. A channel is formed in an interface between the epitaxial regrowth layer and a gate insulating film, so that mobility of carriers improves and on-resistance of an element decreases.

主权项

1. A manufacturing method of a semiconductor device, comprising the steps of:
(a) forming a first nitride semiconductor layer over a substrate; (b) forming a second nitride semiconductor layer whose electron affinity is smaller than that of the first nitride semiconductor layer over the first nitride semiconductor layer; (c) forming an insulating film over the second nitride semiconductor layer; (d) forming a trench which penetrates the insulating film and the second nitride semiconductor layer and reaches inside of the first nitride semiconductor layer by etching the insulating film, the second nitride semiconductor layer, and the first nitride semiconductor layer; (e) forming a third nitride semiconductor layer over a side surface and a bottom surface of the trench by using an epitaxial growth method; (f) forming a gate insulating film over the third nitride semiconductor layer, and (g) forming a gate electrode over the gate insulating film.