公开(公告)号：US20170309752A1

公开(公告)日：2017-10-26

申请号：US15488626

申请日：2017-04-17

Applicant: Semiconductor Energy Laboratory Co., Ltd.

Inventor： Shunpei YAMAZAKI ,  Daisuke MATSUBAYASHI ,  Ryo TOKUMARU ,  Yasumasa YAMANE ,  Kiyofumi OGINO ,  Taichi ENDO ,  Hajime KIMURA

IPC: H01L29/786 ,  H01L29/66 ,  H01L27/12 ,  H01L27/105

CPC classification number: H01L29/78606 ,  H01L27/1052 ,  H01L27/1207 ,  H01L27/1225 ,  H01L27/124 ,  H01L27/1255 ,  H01L29/66969 ,  H01L29/78648 ,  H01L29/7869

Abstract: A highly reliable semiconductor device is provided. The semiconductor device includes a first barrier insulating film; a first gate electrode thereover; a first gate insulating film thereover; an oxide semiconductor film thereover; source and drain electrodes over the oxide semiconductor film; a second gate insulating film over the oxide semiconductor film; a second gate electrode over the second gate insulating film; a second barrier insulating film that covers the oxide semiconductor film, the source and the drain electrodes, and the second gate electrode, and is in contact with side surfaces of the oxide semiconductor film and the source and drain electrodes; and a third barrier insulating film thereover. The first to third barrier insulating films are less likely to transmit hydrogen, water, and oxygen than the first and second gate insulating films. The third barrier insulating film is thinner than the second barrier insulating film. The source and drain electrodes each includes a conductive oxide film in contact with the oxide semiconductor film. The conductive oxide film has more oxygen vacancies than the oxide semiconductor film.