Semiconductor device and manufacturing method of the same

Abstract

The objective of the present invention is to provide a semiconductor device of a hetero-junction field effect transistor that is capable of obtaining a high output and a high breakdown voltage and a manufacturing method of the same. The present invention is a semiconductor device of a hetero junction field effect transistor provided with an Al x Ga 1-x N channel layer with a composition ratio of Al being x (0<x<1) formed on a substrate, an Al y Ga 1-y N barrier layer with a composition of Al being y (0<y≦1) formed on the channel layer, and source/drain electrodes and a gate electrode formed on the barrier layer, wherein the composition ratio y is larger than the composition ratio x.

1 . A semiconductor device provided with a hetero junction field effect transistor in which a channel layer comprising a first nitride semiconductor and a barrier layer comprising a second nitride semiconductor having a larger band gap than that of said first nitride semiconductor form a hetero-junction, wherein the band gap of said first nitride semiconductor in said channel layer is 3.8 eV or more, and at least a part of a portion located immediately below source/drain electrodes of said hetero-junction field effect transistor in said barrier layer is thinner than at a portion located immediately below a gate electrode of said hetero junction field effect transistor in said barrier layer. 
     
     
         2 . A semiconductor device provided with a hetero junction field effect transistor in which a channel layer comprising a first nitride semiconductor and a barrier layer comprising a second nitride semiconductor having a larger band gap than that of said first nitride semiconductor form a hetero-junction, wherein said band gap of said barrier layer is 4.5 eV or more, and at least a part of a portion located immediately below source/drain electrodes of said hetero-junction field effect transistor in said barrier layer is thinner than at a portion located immediately below a gate electrode of said hetero junction field effect transistor in said barrier layer. 
     
     
         3 . A semiconductor device provided with a hetero junction field effect transistor in which a channel layer comprising a first nitride semiconductor and a barrier layer comprising a second nitride semiconductor having a larger band gap than that of said first nitride semiconductor form a hetero junction, wherein said first nitride semiconductor in said channel layer is Al x Ga 1-x N (0.16≦x<1), and at least a part of a portion located immediately below source/drain electrodes of said hetero junction field effect transistor in said barrier layer is thinner than at a portion located immediately below a gate electrode of said hetero-junction field effect transistor in said barrier layer. 
     
     
         4 . A semiconductor device provided with a hetero junction field effect transistor in which a channel layer comprising a first nitride semiconductor and a barrier layer comprising a second nitride semiconductor having a larger band gap than that of said first nitride semiconductor form a hetero junction, wherein said second nitride semiconductor in said barrier layer is Al y Ga 1-y N (0.39≦y<1), and at least a part of a portion located immediately below source/drain electrodes of said hetero junction field effect transistor in said barrier layer is thinner than at a portion located immediately below a gate electrode of said hetero-junction field effect transistor in said barrier layer.