Patent ID: 9293597
Filing Date: 2016-03-22
CPC Classification: H01L

Claim Text:
1. An oxide semiconductor device comprising a gate electrode formed over a main surface of a substrate, a gate insulating film formed to a layer over the gate electrode, a channel layer formed to a layer over the gate insulating film and a source electrode and a drain electrode formed with a predetermined distance therebetween to a layer over the channel layer, in which the channel layer includes an oxide semiconductor composed mainly of zinc oxide and tin oxide, the channel layer contains a contaminant that is a group III element, having an impurity concentration (B), the channel layer contains a counter dopant, having an impurity concentration (A), that is group IV element, a group V element, or both of the group IV element and the group V element, and a ratio between the impurity concentration (A) of the counter dopant that is the group IV element, the group V element, or both of the group IV element and the group V element and the impurity concentration (B) of the contaminant group III element is: A/B≦1.0.