# US 12,119,408 B2 · Method for forming oxide semiconductor film, semiconductor device, and method for manufacturing semiconductor device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,119,408 B2 - Document ID: US12119408B2 - Status: Granted - Kind: B2 - Application number: 18/243,688 - Filed: 2023-09-08 - Published: 2023-12-28 - Granted: 2024-10-15 - Earliest claimed: 2011-05-25 - Assignees: Semiconductor Energy Laboratory Co., Ltd. - Applicants: Semiconductor Energy Laboratory Co., Ltd. - Inventors: Shunpei Yamazaki; Masahiro Watanabe; Mitsuo Mashiyama; Kenichi Okazaki; Motoki Nakashima; Hideyuki Kishida - Web page: https://patentgrep.com/patent/US12119408B2 ## CPC - H01L 29/7869 - H01L 21/02554 - H01L 21/02565 - H01L 21/02631 - H01L 21/823412 - H01L 21/82345 - H01L 21/823475 - H01L 27/1225 - H01L 27/1229 - H01L 27/1233 - H01L 29/66969 - H01L 29/78603 - H01L 29/78606 - H01L 29/78618 - H01L 29/78672 - H01L ## Abstract The impurity concentration in the oxide semiconductor film is reduced, and a highly reliability can be obtained. ## Claims ### Claim 1 A semiconductor device comprising: a first transistor and a second transistor, wherein the first transistor is provided over the second transistor, wherein a portion where one of a source and a drain of the first transistor is electrically connected to a gate of the second transistor is provided, wherein data is written in the portion through the first transistor, wherein the data is kept when the first transistor is in an off-state, wherein a channel formation region of the first transistor includes a first oxide semiconductor layer, wherein a channel formation region of the second transistor includes a second oxide semiconductor layer, wherein the first oxide semiconductor layer includes a crystal whose c-axis is arranged perpendicular to a surface of the first oxide semiconductor layer, and wherein the second oxide semiconductor layer includes a crystal whose c-axis is arranged perpendicular to a surface of the second oxide semiconductor layer. ### Claim 2 (depends on 1) The semiconductor device according to claim 1, wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer is In—Zn—O-based oxide semiconductor, Sn—Zn—O-based oxide semiconductor, Al—Zn—O-based oxide semiconductor, Zn—Mg—O-based oxide semiconductor, Sn—Mg—O-based oxide semiconductor, In—Mg—O-based oxide semiconductor, In—Ga—O-based oxide semiconductor, In—Ga—Zn—O-based oxide semiconductor, In—Al—Zn—O-based oxide semiconductor, In—Sn—Zn—O-based oxide semiconductor, Sn—Ga—Zn—O-based oxide semiconductor, Al—Ga—Zn—O-based oxide semiconductor, Sn—Al—Zn—O-based oxide semiconductor, In—Hf—Zn—O-based oxide semiconductor, In—La—Zn—O-based semiconductor, In—Ce—Zn—O-based oxide semiconductor, In—Pr—Zn—O-based oxide semiconductor, In—Nd—Zn—O-based oxide semiconductor, In—Sm—Zn—O-based oxide semiconductor, In—Eu—Zn—O-based oxide semiconductor, In—Gs—Zn—O-based oxide semiconductor, In—Tb—Zn—O-based oxide semiconductor, In—Dy—Zn—O-based oxide semiconductor, In—Ho—Zn—O-based oxide semiconductor, In—Er—Zn—O-based oxide semiconductor, In—Tm—Zn—O-based oxide semiconductor, In—Yb—Zn—O-based oxide semiconductor, In—Lu—Zn—O-based oxide semiconductor, In—Sn—Ga—Zn—O-based oxide semiconductor, In—Hf—Ga—Zn—O-based oxide semiconductor, In—Al—Ga—Zn—O-based oxide semiconductor, In—Sn—Al—Zn—O-based oxide semiconductor, In—Sn—Hf—Zn—O-based oxide semiconductor, or In—Hf—Al—Zn—O-based oxide semiconductor. ### Claim 3 (depends on 1) The semiconductor device according to claim 1, wherein a hydrogen concentration measured by secondary ion mass spectrometry in the first oxide semiconductor layer and the second oxide semiconductor layer is 5×1019 atoms/cm3 or lower. ### Claim 4 (depends on 1) The semiconductor device according to claim 1, wherein a carbon concentration measured by secondary ion mass spectrometry in the first oxide semiconductor layer and the second oxide semiconductor layer is 5×1019 atoms/cm3 or lower. ### Claim 5 (depends on 1) The semiconductor device according to claim 1, wherein a nitrogen concentration measured by secondary ion mass spectrometry in the first oxide semiconductor layer and the second oxide semiconductor layer is 5×1019 atoms/cm3 or lower. ### Claim 6 (depends on 1) The semiconductor device according to claim 1, wherein an off-state current of the first transistor and the second transistor is 1×10−18 A or less. ### Claim 7 A semiconductor device comprising: a first transistor and a second transistor, wherein the first transistor is provided over the second transistor, wherein a floating gate portion is provided where one of a source and a drain of the first transistor is electrically connected to a gate of the second transistor, wherein a channel formation region of the first transistor includes a first oxide semiconductor layer, wherein a channel formation region of the second transistor includes a second oxide semiconductor layer, wherein the first oxide semiconductor layer includes a crystal whose c-axis is arranged perpendicular to a surface of the first oxide semiconductor layer, and wherein the second oxide semiconductor layer includes a crystal whose c-axis is arranged perpendicular to a surface of the second oxide semiconductor layer. ### Claim 8 (depends on 7) The semiconductor device according to claim 7, wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer is In—Zn—O-based oxide semiconductor, Sn—Zn—O-based oxide semiconductor, Al—Zn—O-based oxide semiconductor, Zn—Mg—O-based oxide semiconductor, Sn—Mg—O-based oxide semiconductor, In—Mg—O-based oxide semiconductor, In—Ga—O-based oxide semiconductor, In—Ga—Zn—O-based oxide semiconductor, In—Al—Zn—O-based oxide semiconductor, In—Sn—Zn—O-based oxide semiconductor, Sn—Ga—Zn—O-based oxide semiconductor, Al—Ga—Zn—O-based oxide semiconductor, Sn—Al—Zn—O-based oxide semiconductor, In—Hf—Zn—O-based oxide semiconductor, In—La—Zn—O-based semiconductor, In—Ce—Zn—O-based oxide semiconductor, In—Pr—Zn—O-based oxide semiconductor, In—Nd—Zn—O-based oxide semiconductor, In—Sm—Zn—O-based oxide semiconductor, In—Eu—Zn—O-based oxide semiconductor, In—Gs—Zn—O-based oxide semiconductor, In—Tb—Zn—O-based oxide semiconductor, In—Dy—Zn—O-based oxide semiconductor, In—Ho—Zn—O-based oxide semiconductor, In—Er—Zn—O-based oxide semiconductor, In—Tm—Zn—O-based oxide semiconductor, In—Yb—Zn—O-based oxide semiconductor, In—Lu—Zn—O-based oxide semiconductor, In—Sn—Ga—Zn—O-based oxide semiconductor, In—Hf—Ga—Zn—O-based oxide semiconductor, In—Al—Ga—Zn—O-based oxide semiconductor, In—Sn—Al—Zn—O-based oxide semiconductor, In—Sn—Hf—Zn—O-based oxide semiconductor, or In—Hf—Al—Zn—O-based oxide semiconductor. ### Claim 9 (depends on 7) The semiconductor device according to claim 7, wherein a hydrogen concentration measured by secondary ion mass spectrometry in the first oxide semiconductor layer and the second oxide semiconductor layer is 5×1019 atoms/cm3 or lower. ### Claim 10 (depends on 7) The semiconductor device according to claim 7, wherein a carbon concentration measured by secondary ion mass spectrometry in the first oxide semiconductor layer and the second oxide semiconductor layer is 5×1019 atoms/cm3 or lower. ### Claim 11 (depends on 7) The semiconductor device according to claim 7, wherein a nitrogen concentration measured by secondary ion mass spectrometry in the first oxide semiconductor layer and the second oxide semiconductor layer is 5×1019 atoms/cm3 or lower. ### Claim 12 (depends on 7) The semiconductor device according to claim 7, wherein an off-state current of the first transistor and the second transistor is 1×10−18 A or less. ### Claim 13 A semiconductor device comprising: a first transistor, a second transistor, and a capacitor element, wherein the first transistor is provided over the second transistor, wherein a portion where one of a source and a drain of the first transistor is electrically connected to a gate of the second transistor is provided, wherein data is written in the portion through the first transistor, wherein the data is kept when the first transistor is in an off-state, wherein a channel formation region of the first transistor includes a first oxide semiconductor layer, wherein a channel formation region of the second transistor includes a second oxide semiconductor layer, wherein the first oxide semiconductor layer includes a crystal whose c-axis is arranged perpendicular to a surface of the first oxide semiconductor layer, wherein the second oxide semiconductor layer includes a crystal whose c-axis is arranged perpendicular to a surface of the second oxide semiconductor layer, and wherein the capacitor element is electrically connected to the gate of the second transistor. ### Claim 14 (depends on 13) The semiconductor device according to claim 13, wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer is In—Zn—O-based oxide semiconductor, Sn—Zn—O-based oxide semiconductor, Al—Zn—O-based oxide semiconductor, Zn—Mg—O-based oxide semiconductor, Sn—Mg—O-based oxide semiconductor, In—Mg—O-based oxide semiconductor, In—Ga—O-based oxide semiconductor, In—Ga—Zn—O-based oxide semiconductor, In—Al—Zn—O-based oxide semiconductor, In—Sn—Zn—O-based oxide semiconductor, Sn—Ga—Zn—O-based oxide semiconductor, Al—Ga—Zn—O-based oxide semiconductor, Sn—Al—Zn—O-based oxide semiconductor, In—Hf—Zn—O-based oxide semiconductor, In—La—Zn—O-based semiconductor, In—Ce—Zn—O-based oxide semiconductor, In—Pr—Zn—O-based oxide semiconductor, In—Nd—Zn—O-based oxide semiconductor, In—Sm—Zn—O-based oxide semiconductor, In—Eu—Zn—O-based oxide semiconductor, In—Gs—Zn—O-based oxide semiconductor, In—Tb—Zn—O-based oxide semiconductor, In—Dy—Zn—O-based oxide semiconductor, In—Ho—Zn—O-based oxide semiconductor, In—Er—Zn—O-based oxide semiconductor, In—Tm—Zn—O-based oxide semiconductor, In—Yb—Zn—O-based oxide semiconductor, In—Lu—Zn—O-based oxide semiconductor, In—Sn—Ga—Zn—O-based oxide semiconductor, In—Hf—Ga—Zn—O-based oxide semiconductor, In—Al—Ga—Zn—O-based oxide semiconductor, In—Sn—Al—Zn—O-based oxide semiconductor, In—Sn—Hf—Zn—O-based oxide semiconductor, or In—Hf—Al—Zn—O-based oxide semiconductor. ### Claim 15 (depends on 13) The semiconductor device according to claim 13, wherein a hydrogen concentration measured by secondary ion mass spectrometry in the first oxide semiconductor layer and the second oxide semiconductor layer is 5×1019 atoms/cm3 or lower. ### Claim 16 (depends on 13) The semiconductor device according to claim 13, wherein a carbon concentration measured by secondary ion mass spectrometry in the first oxide semiconductor layer and the second oxide semiconductor layer is 5×1019 atoms/cm3 or lower. ### Claim 17 (depends on 13) The semiconductor device according to claim 13, wherein a nitrogen concentration measured by secondary ion mass spectrometry in the first oxide semiconductor layer and the second oxide semiconductor layer is 5×1019 atoms/cm3 or lower. ### Claim 18 (depends on 13) The semiconductor device according to claim 13, wherein an off-state current of the first transistor and the second transistor is 1×10−18 A or less. ### Claim 19 A semiconductor device comprising: a first transistor, a second transistor, and a capacitor element, wherein the first transistor is provided over the second transistor, wherein a floating gate portion is provided where one of a source and a drain of the first transistor is electrically connected to a gate of the second transistor, wherein a channel formation region of the first transistor includes a first oxide semiconductor layer, wherein a channel formation region of the second transistor includes a second oxide semiconductor layer, wherein the first oxide semiconductor layer includes a crystal whose c-axis is arranged perpendicular to a surface of the first oxide semiconductor layer, wherein the second oxide semiconductor layer includes a crystal whose c-axis is arranged perpendicular to a surface of the second oxide semiconductor layer, and wherein the capacitor element is electrically connected to the gate of the second transistor. ### Claim 20 (depends on 19) The semiconductor device according to claim 19, wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer is In—Zn—O-based oxide semiconductor, Sn—Zn—O-based oxide semiconductor, Al—Zn—O-based oxide semiconductor, Zn—Mg—O-based oxide semiconductor, Sn—Mg—O-based oxide semiconductor, In—Mg—O-based oxide semiconductor, In—Ga—O-based oxide semiconductor, In—Ga—Zn—O-based oxide semiconductor, In—Al—Zn—O-based oxide semiconductor, In—Sn—Zn—O-based oxide semiconductor, Sn—Ga—Zn—O-based oxide semiconductor, Al—Ga—Zn—O-based oxide semiconductor, Sn—Al—Zn—O-based oxide semiconductor, In—Hf—Zn—O-based oxide semiconductor, In—La—Zn—O-based semiconductor, In—Ce—Zn—O-based oxide semiconductor, In—Pr—Zn—O-based oxide semiconductor, In—Nd—Zn—O-based oxide semiconductor, In—Sm—Zn—O-based oxide semiconductor, In—Eu—Zn—O-based oxide semiconductor, In—Gs—Zn—O-based oxide semiconductor, In—Tb—Zn—O-based oxide semiconductor, In—Dy—Zn—O-based oxide semiconductor, In—Ho—Zn—O-based oxide semiconductor, In—Er—Zn—O-based oxide semiconductor, In—Tm—Zn—O-based oxide semiconductor, In—Yb—Zn—O-based oxide semiconductor, In—Lu—Zn—O-based oxide semiconductor, In—Sn—Ga—Zn—O-based oxide semiconductor, In—Hf—Ga—Zn—O-based oxide semiconductor, In—Al—Ga—Zn—O-based oxide semiconductor, In—Sn—Al—Zn—O-based oxide semiconductor, In—Sn—Hf—Zn—O-based oxide semiconductor, or In—Hf—Al—Zn—O-based oxide semiconductor. ### Claim 21 (depends on 19) The semiconductor device according to claim 19, wherein a hydrogen concentration measured by secondary ion mass spectrometry in the first oxide semiconductor layer and the second oxide semiconductor layer is 5×1019 atoms/cm3 or lower. ### Claim 22 (depends on 19) The semiconductor device according to claim 19, wherein a carbon concentration measured by secondary ion mass spectrometry in the first oxide semiconductor layer and the second oxide semiconductor layer is 5×1019 atoms/cm3 or lower. ### Claim 23 (depends on 19) The semiconductor device according to claim 19, wherein a nitrogen concentration measured by secondary ion mass spectrometry in the first oxide semiconductor layer and the second oxide semiconductor layer is 5×1019 atoms/cm3 or lower. ### Claim 24 (depends on 19) The semiconductor device according to claim 19, wherein an off-state current of the first transistor and the second transistor is 1×10−18 A or less.