Metal oxide, formation method of metal oxide, semiconductor device, and manufacturing method of semiconductor device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsShunpei Yamazaki, Yoshihiro Komatsu, Hiromi Sawai, Ryosuke Watanabe, Shinobu Kawaguchi, Shunichi Ito
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Abstract
A novel metal oxide is provided. The metal oxide includes a c-axis aligned crystal and contains indium, an element M (M is gallium, aluminum, yttrium, or tin), and zinc. In the metal oxide, the diffusion length of hydrogen is 200 nm or less and absorption due to localized states measured by a CPM is 0.01/cm or less. The diffusion length of hydrogen is calculated with the temperature being 400° C. and 1 hour.
Claims7
A metal oxide film comprising a c-axis aligned crystal,
- wherein the metal oxide film comprises indium, gallium, and zinc,
- wherein in the metal oxide film, an atomic ratio of indium, gallium, and zinc is 4:2:3 or in a range of ±30% thereof,
- wherein a diffusion length of hydrogen in the metal oxide film is 200 nm or less,
- wherein the diffusion length is calculated with a temperature being 400° C. and 1 hour, and
- wherein in the metal oxide film, absorption due to a localized state calculated by a constant photocurrent method (CPM) is 1×10−2 cm−1 or less.
A semiconductor device comprising:
- a metal oxide layer;
- a first conductor and a second conductor in contact with the metal oxide layer;
- a third conductor overlapping the metal oxide layer;
- and
- an insulator positioned between the metal oxide layer and the third conductor,
- wherein the metal oxide layer comprises indium, gallium, and zinc,
- wherein the metal oxide layer comprises a c-axis aligned crystal,
- wherein in the metal oxide layer, an atomic ratio of indium, gallium, and zinc is 4:2:3 or in a range of ±30% thereof,
- wherein a diffusion length of hydrogen in the metal oxide layer is 200 nm or less,
- wherein the diffusion length is calculated with a temperature being 400° C. and 1 hour, and
- wherein in the metal oxide layer, absorption due to a localized state calculated by a constant photocurrent method (CPM) is 1×10−2 cm−1 or less.
A semiconductor device comprising:
- a metal oxide layer;
- a first conductor and a second conductor over the metal oxide layer;
- an insulator positioned between the first conductor and the second conductor and positioned over the metal oxide layer;
- and
- a third conductor over the insulator,
- wherein the metal oxide layer comprises indium, gallium, and zinc,
- wherein the metal oxide layer comprises a c-axis aligned crystal,
- wherein in the metal oxide layer, an atomic ratio of indium, gallium, and zinc is 4:2:3 or in a range of ±30% thereof,
- wherein a diffusion length of hydrogen in the metal oxide layer is 200 nm or less,
- wherein the diffusion length is calculated with a temperature being 400° C. and 1 hour, and
- wherein in the metal oxide layer, absorption due to a localized state calculated by a constant photocurrent method (CPM) is 1×10−2 cm−1 or less.
Dependencies are inferred from the claim text.