Patent ID: 9349751
Filing Date: 2016-05-24
CPC Classification: G02F,H01L

Claim Text:
1. A semiconductor device comprising: a first circuit comprising a first transistor and a second transistor over a substrate; and a second circuit comprising a third transistor over the substrate; wherein the first transistor comprises a first oxide semiconductor film, a second oxide semiconductor film and a first gate electrode, the first gate electrode overlapping with the first oxide semiconductor film and the second oxide semiconductor film, wherein the second transistor comprises a third oxide semiconductor film, wherein the third transistor comprises a fourth oxide semiconductor film, wherein the second oxide semiconductor film, the third oxide semiconductor film and the fourth oxide semiconductor film comprise a same material, wherein a material of the first oxide semiconductor film is different from a material of the second oxide semiconductor film, wherein the first transistor comprises a first back gate electrode connected to the first gate electrode, and wherein a top surface and a side surface of the first oxide semiconductor film are covered with the second oxide semiconductor film.