Semiconductor device

摘要

To provide a highly reliable semiconductor device which includes a transistor including an oxide semiconductor, in a semiconductor device including a staggered transistor having a bottom-gate structure provided over a glass substrate, a gate insulating film in which a first gate insulating film and a second gate insulating film, whose compositions are different from each other, are stacked in this order is provided over a gate electrode layer. Alternatively, in a staggered transistor having a bottom-gate structure, a protective insulating film is provided between a glass substrate and a gate electrode layer. A metal element contained in the glass substrate has a concentration lower than or equal to 5×1018 atoms/cm3 at the interface between the first gate insulating film and the second gate insulating film or the interface between the gate electrode layer and a gate insulating film.

主权项

1. A semiconductor device comprising:
a gate electrode layer over a glass substrate comprising one or more metal elements; a first gate insulating film over the gate electrode layer; a second gate insulating film over and in contact with the first gate insulating film; an oxide semiconductor film over the second gate insulating film; and a source electrode layer and a drain electrode layer over the oxide semiconductor film, wherein a composition of the first gate insulating film is different from a composition of the second gate insulating film, and wherein, at an interface between the first gate insulating film and the second gate insulating film, a concentration of the one or more metal elements diffused from the glass substrate is lower than or equal to 5×1018 atoms/cm3.