US 12,087,824 B2
Composite oxide semiconductor and transistor
Shunpei Yamazaki, Setagaya (JP); Yasuharu Hosaka, Tochigi (JP); Yukinori Shima, Tatebayashi (JP); Junichi Koezuka, Tochigi (JP); and Kenichi Okazaki, Tochigi (JP)
Assigned to Semiconductor Energy Laboratory Co., Ltd., Atsugi (JP)
Filed by Semiconductor Energy Laboratory Co., Ltd., Atsugi (JP)
Filed on Jul. 31, 2023, as Appl. No. 18/228,134.
Application 18/228,134 is a continuation of application No. 17/725,643, filed on Apr. 21, 2022, granted, now 11,728,392.
Application 17/725,643 is a continuation of application No. 16/926,861, filed on Jul. 13, 2020, granted, now 11,316,016, issued on Apr. 26, 2022.
Application 16/926,861 is a continuation of application No. 15/592,712, filed on May 11, 2017, granted, now 10,879,360, issued on Dec. 29, 2020.
Claims priority of application No. 2016-100939 (JP), filed on May 19, 2016.
Prior Publication US 2023/0387217 A1, Nov. 30, 2023
Int. Cl. H01L 29/24 (2006.01); H01L 29/06 (2006.01); H01L 29/10 (2006.01); H01L 29/423 (2006.01); H01L 29/49 (2006.01); H01L 29/786 (2006.01)
CPC H01L 29/24 (2013.01) [H01L 29/0692 (2013.01); H01L 29/1037 (2013.01); H01L 29/42384 (2013.01); H01L 29/4908 (2013.01); H01L 29/78648 (2013.01); H01L 29/7869 (2013.01); H01L 29/78696 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A composite oxide semiconductor comprising a plurality of first regions and a plurality of second regions,
wherein the composite oxide semiconductor is over a substrate,
wherein each of the plurality of first regions comprises indium and gallium,
wherein each of the plurality of second regions comprises indium and gallium,
wherein concentrations of gallium in the plurality of first regions are higher than concentrations of gallium in the plurality of second regions,
wherein any two first regions included in the plurality of first regions are arranged parallel to a top surface of the substrate in a cross-sectional image,
wherein any one second region included in the plurality of second regions is interposed between the any two first regions, and
wherein a length of the any one second region is greater than or equal to 0.5 nm and less than or equal to 10 nm in EDX mapping of the cross-sectional image.