IMAGING DEVICE

摘要

An imaging device that is highly stable to irradiation with radial rays such as X-rays and can inhibit a decrease in electrical characteristics is provided. The imaging device takes an image with radial rays such as X-rays and includes pixel circuits arranged in a matrix and a scintillator overlapping the pixel circuits. The pixel circuits each includes a switching transistor with an extremely small off-state current and a light-receiving element which is configured to convert the radial rays to electrical charges. A gate insulating film of the switching transistor has a stacked structure including a silicon nitride film with a thickness of 100 nm to 400 nm and a silicon oxide film or a silicon oxynitride film with a thickness of 5 nm to 20 nm.

主权项

1. A semiconductor device comprising a light-receiving element and a first transistor connected to the light-receiving element, wherein the first transistor comprises:
a gate electrode over an insulating surface; a gate insulating film comprising a first insulating film over the gate electrode and a second insulating film over the first insulating film; and an oxide semiconductor layer over the second insulating film, wherein the first insulating film comprises a silicon nitride, wherein the second insulating film comprises a silicon oxide or a silicon oxynitride, wherein the first insulating film has a thickness of 100 nm to 400 nm, and wherein the second insulating film has a thickness of 5 nm to 20 nm.