| 摘要 |
<p>PURPOSE:To reduce a leak current when operating voltage holding by specifying the relationship among upper limit and Fermi energy of a valence electron band of a first semiconductor layer; lowest limit energy of the conduction band of a second semiconductor layer, upper limit and Fermi energy of a valence electron band; and lowest limit and Fermi energy of the conduction band of a third semiconductor layer. CONSTITUTION:In a first semiconductor layer 18 forming a semiconductor layer 24 being a stacked film to form a channel, Ec1 denotes lowest limit energy of a conductive band, Evl denotes upper limit energy of a valence electron band, and Ef1 denotes Fermi energy. Also, in a second semiconductor layer 20, Ec2 denotes lowest limit energy of a conductive band, Ev2 denotes upper limit energy of a valence electron band and Ef2 denotes Fermi energy. Further, in a third semiconductor layer 22, Ec3 denotes lowest limit energy of a conductor Ev3 denotes upper limit energy of a valence electron band and Ef3 denotes Fermi energy. Here, ¦Ec3-Ef3¦>¦Ec2-Ef2¦ and ¦Ef1-Ev1¦>¦Ef2-Ev2¦.</p> |
