Semiconductor Energy Laboratory Co., Ltd.

Hirokazu Watanabe

Shunpei Yamazaki

Hideomi Suzawa

Tetsuhiro Tanaka

Daisuke Matsubayashi

Yasumasa Yamane

Yuhei Sato

Shinji Ohno

Naoto Kusumoto

A semiconductor device having a reduced amount of oxygen vacancy in a channel formation region of an oxide semiconductor is provided. Further, a semiconductor device which includes an oxide semiconductor and has improved electric characteristics is provided. Furthermore, a methods for manufacturing the semiconductor device is provided. An oxide semiconductor film is formed; a conductive film is formed over the oxide semiconductor film at the same time as forming a low-resistance region between the oxide semiconductor film and the conductive film; the conductive film is processed to form a source electrode and a drain electrode; and oxygen is added to the low-resistance region between the source electrode and the drain electrode, so that a channel formation region having a higher resistance than the low-resistance region is formed and a first low-resistance region and a second low-resistance region between which the channel formation region is positioned are formed.

Semiconductor device and method for manufacturing the same

A transistor excellent in electrical characteristics and a method for manufacturing the transistor are provided. The transistor includes an oxide semiconductor layer including a source region, a drain region, and a channel formation region over an insulating surface; a gate insulating film over the oxide semiconductor layer; a gate electrode overlapping with the channel formation region, over the gate insulating film; a source electrode in contact with the source region; and a drain electrode in contact with the drain region. The source region and the drain region include a portion having higher oxygen concentration than the channel formation region.

To provide a highly reliable semiconductor device. The semiconductor device includes a first oxide layer over an insulating film; an oxide semiconductor layer over the first oxide layer; a gate insulating film over the oxide semiconductor layer; and a gate electrode over the gate insulating film. The first oxide layer contains indium. The oxide semiconductor layer contains indium and includes a channel formation region. The distance from the interface to the channel formation region is 20 nm or more, preferably 30 nm or more, further preferably 40 nm or more, still further preferably 60 nm or more.

To provide a semiconductor device which includes a gate insulating film with high withstand voltage and thus can have high reliability. The semiconductor device includes an oxide semiconductor film over an insulating surface; a pair of first conductive films over the oxide semiconductor film; a first insulating film, a second insulating film, and a third insulating film which are stacked in this order over the oxide semiconductor film and the pair of first conductive films; and a second conductive film overlapping with the oxide semiconductor film over the first to third insulating films. The first insulating film and the third insulating film contain silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, aluminum oxide, or aluminum oxynitride. The second insulating film contains gallium oxide, zirconium oxide, or hafnium oxide.

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Kanagawa, Japan

Hirokazu Watanabe