Field effect transistor having a channel comprising an oxide semiconductor material including indium and zinc

摘要

Disclosed herein is a field-effect transistor comprising a channel comprised of an oxide semiconductor material including In and Zn. The atomic compositional ratio expressed by In/(In + Zn) is not less than 35 atomic% and not more than 55 atomic%. Ga is not included in the oxide semiconductor material or the atomic compositional ratio expressed by Ga/(In + Zn + Ga) is set to be 30 atomic% or lower when Ga is included therein. The transistor has improved S-value and field-effect mobility.