Patent attributes
A semiconductor device with favorable electrical characteristics is provided. A semiconductor device having stable electrical characteristics is provided. The semiconductor device includes a semiconductor layer containing a metal oxide, a first insulating layer, a second insulating layer, a third insulating layer containing a nitride, and a first conductive layer. The first insulating layer includes a projecting first region that overlaps with the semiconductor layer and a second region that does not overlap with the semiconductor layer and is thinner than the first region. The second insulating layer is provided to cover a top surface of the second region, a side surface of the first region, and the semiconductor layer. The first conductive layer is provided over the second insulating layer and a bottom surface of the first conductive layer over the second region includes a portion positioned below a bottom surface of the semiconductor layer.