Thin film transistor and manufacturing method thereof

摘要

Disclosed is a thin film transistor including: a gate insulating layer covering a gate electrode; a microcrystalline semiconductor region over the gate insulating layer; a pair of amorphous semiconductor region over the microcrystalline semiconductor; a pair of impurity semiconductor layers over the amorphous semiconductor regions; and wirings over the impurity semiconductor layers. The microcrystalline semiconductor region has a surface having a projection and depression on the gate insulating layer side. The microcrystalline semiconductor region includes a first microcrystalline semiconductor region which is not covered with the amorphous regions and a second microcrystalline semiconductor region which is in contact with the amorphous semiconductor regions. A thickness d1 of the first microcrystalline semiconductor region is smaller than a thickness d2 of the second microcrystalline semiconductor region and d1 is greater than or equal to 30 nm.