US 12,278,292 B2
Semiconductor device and manufacturing method of semiconductor device
Shunpei Yamazaki, Tokyo (JP); Kenichi Okazaki, Tochigi (JP); Masami Jintyou, Tochigi (JP); Takahiro Iguchi, Tochigi (JP); and Yukinori Shima, Gunma (JP)
Assigned to Semiconductor Energy Laboratory Co., Ltd., Kanagawa-ken (JP)
Filed by SEMICONDUCTOR ENERGY LABORATORY CO., LTD., Atsugi (JP)
Filed on Sep. 21, 2022, as Appl. No. 17/949,632.
Application 17/949,632 is a division of application No. 16/982,182, granted, now 11,482,626, previously published as PCT/IB2019/052105, filed on Mar. 15, 2019.
Claims priority of application No. 2018-064931 (JP), filed on Mar. 29, 2018.
Prior Publication US 2023/0020210 A1, Jan. 19, 2023
Int. Cl. H01L 29/786 (2006.01); H01L 27/15 (2006.01); H01L 29/66 (2006.01); H10K 59/131 (2023.01)
CPC H01L 29/7869 (2013.01) [H01L 27/156 (2013.01); H01L 29/66969 (2013.01); H10K 59/131 (2023.02)] 15 Claims
OG exemplary drawing
 
1. A method for manufacturing a semiconductor device, comprising steps of:
forming a first insulating layer comprising an oxide;
depositing a first metal oxide film over the first insulating layer;
forming a resist mask over the first metal oxide film and etching part of the first metal oxide film that is not covered with the resist mask so that a semiconductor layer is formed and part of the first insulating layer is exposed;
etching part of the first insulating layer that is not covered with the resist mask to make the part thin so that a first region overlapping with the semiconductor layer and a second region not overlapping with the semiconductor layer are formed;
removing the resist mask;
forming a second insulating film covering the semiconductor layer, a side surface of the first region, and a top surface of the second region;
forming over the second insulating film, a second metal oxide film whose top surface overlapping with the second region is below a bottom surface of the semiconductor layer;
forming a first conductive film over the second metal oxide film,
etching part of the first conductive film, part of the second metal oxide film, and part of the second insulating film so that a portion of the semiconductor layer is exposed; and
forming a first layer comprising a nitride in contact with the portion of the semiconductor layer and then performing heat treatment.