Semiconductor device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsShunpei YAMAZAKI, Masayuki SAKAKURA, Hideomi SUZAWA
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Abstract
A semiconductor device having a structure which can prevent a decrease in electrical characteristics due to miniaturization is provided. The semiconductor device includes, over an insulating surface, a stack in which a first oxide semiconductor layer and a second oxide semiconductor layer are sequentially formed, and a third oxide semiconductor layer covering part of a surface of the stack. The third oxide semiconductor layer includes a first layer in contact with the stack and a second layer over the first layer. The first layer includes a microcrystalline layer, and the second layer includes a crystalline layer in which c-axes are aligned in a direction perpendicular to a surface of the first layer.
Claims1
A semiconductor device comprising:
- a stack comprising a first oxide semiconductor layer and a second oxide semiconductor layer sequentially formed over an insulating surface;
- and
- a third oxide semiconductor layer,
- wherein the third oxide semiconductor layer comprises a first layer in contact with part of the insulating surface and part of the stack,
- wherein the third oxide semiconductor layer comprises a second layer over the first layer,
- wherein the first layer comprises a microcrystalline layer, and
- wherein the second layer comprises a crystalline layer in which c-axes are aligned in a direction substantially perpendicular to a surface of the first layer.
Dependencies are inferred from the claim text.