Thin film transistor with channel including microcrystalline and amorphous semiconductor regions

A thin film transistor, comprising:

• a gate electrode;
• a gate insulating layer covering the gate electrode;
• a back-gate electrode provided opposite site of the gate electrode;
• an interlayer insulating layer in contact with the back-gate electrode;
• a semiconductor layer which includes a microcrystalline semiconductor region and an amorphous semiconductor region on the microcrystalline semiconductor region and is provided between the gate insulating layer and the interlayer insulating layer;
• an impurity semiconductor layer on the semiconductor layer;
• a wiring on the impurity semiconductor layer;
• a first oxide region provided between the microcrystalline semiconductor region and the wiring;
• and
• a second oxide region provided between a side face of the amorphous semiconductor region and the wiring,
• wherein a line tangent to the highest inclination of an oxygen profile in the first oxide region (m1) and a line tangent to the highest inclination of an oxygen profile in the second oxide region (m2) satisfy a relation of 1<m1/m2<10, on the semiconductor layer side from an intersection of a profile of an element included in the wiring and a profile of an element included in the semiconductor layer.