Patent ID: 8569797
Filing Date: 2013-10-29
Classification: H01L

Abstract:
1. A field-effect transistor comprising: a substrate; a first semiconductor layer including a plurality of semiconductor layers stacked on said substrate, and including a channel; a source electrode and a drain electrode which are formed on said first semiconductor layer; a gate electrode; and a second semiconductor layer formed on said first semiconductor layer and below said gate electrode, said second semiconductor layer having a conductivity type opposite to a conductivity type of the channel, wherein: said first semiconductor layer has a containing region which contains first impurities, and a non-containing region which does not contain the first impurities, said containing region includes a first region, the first region is defined by a vicinity region of a portion of an interface between the containing region and the non-containing region, said second semiconductor layer includes a second region, the second region is located directly above the first region, a concentration of the first impurities of the second region is lower than a concentration of the first impurities of the first region, and both of said first region and said second region are located directly below an end portion of said gate electrode.