# US 2018/0323306 A1 · Semiconductor device and method for manufacturing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323306 A1 - Document ID: US20180323306A1 - Status: Published application - Kind: A1 - Application number: 16/038,515 - Filed: 2018-07-18 - Published: 2018-11-08 - Earliest claimed: 2011-11-25 - Assignees: Semiconductor Energy Laboratory Co., Ltd. - Applicants: Semiconductor Energy Laboratory Co., Ltd. - Inventors: Hiromichi GODO; Tetsuhiro TANAKA - Web page: https://patentgrep.com/patent/US20180323306A1 ## CPC - H10D 30/6755: {Oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate} - H10D 30/6739: {Conductor-insulator-semiconductor electrodes} - H10P 14/3426: {Oxides} - H10P 14/3434: {being oxide semiconductor materials (Group IIB-VIA semiconductor materials H10P14/3424)} - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract To reduce oxygen vacancies in an oxide semiconductor film and the vicinity of the oxide semiconductor film and to improve electric characteristics of a transistor including the oxide semiconductor film. A semiconductor device includes a gate electrode whose Gibbs free energy for oxidation is higher than that of a gate insulating film. In a region where the gate electrode is in contact with the gate insulating film, oxygen moves from the gate electrode to the gate insulating film, which is caused because the gate electrode has higher Gibbs free energy for oxidation than the gate insulating film. The oxygen passes through the gate insulating film and is supplied to the oxide semiconductor film in contact with the gate insulating film, whereby oxygen vacancies in the oxide semiconductor film and the vicinity of the oxide semiconductor film can be reduced. ## Claims ### Claim 1 (canceled) ### Claim 2 A semiconductor device comprising: an oxide semiconductor over a substrate; a gate electrode overlapping with the oxide semiconductor; a gate insulating film provided between the oxide semiconductor and the gate electrode, wherein the gate insulating film is in direct contact with the gate electrode and the oxide semiconductor, wherein the gate insulating film has an oxygen-transmitting property, wherein the gate electrode comprises at least a first region and a second region, wherein the first region and the second region comprise an element of a metal, wherein the first region is closer to the gate insulating film than the second region, wherein an oxygen concentration of the first region is lower than an oxygen concentration of the second region, and wherein the oxide semiconductor comprises indium, zinc, and one selected from the group consisting of Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Ga, Y, Zr, Nb, Mo, Sn, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, and W. ### Claim 3 (depends on 2) The semiconductor device according to claim 2, wherein the element is ruthenium. ### Claim 4 (depends on 2) The semiconductor device according to claim 2, wherein the gate electrode substantially consists of ruthenium and oxygen. ### Claim 5 (depends on 2) The semiconductor device according to claim 2, wherein the gate insulating film comprises a layer, and wherein the layer comprises one selected from the group consisting of aluminum oxide, magnesium oxide, silicon oxide, silicon oxynitride, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide. ### Claim 6 (depends on 2) The semiconductor device according to claim 2, further comprising a base insulating film over the substrate, wherein the gate insulating film is in direct contact with the base insulating film. ### Claim 7 (depends on 2) The semiconductor device according to claim 2, wherein a thickness of the gate electrode is greater than or equal to 30 nm, wherein the first region is at a distance of 3 nm from an interface with the gate insulating film, and wherein the second region is at a distance of 15 nm from the interface with the gate insulating film. ### Claim 8 (depends on 2) The semiconductor device according to claim 2, wherein the gate electrode further comprises a third region over the first region and the second region. ### Claim 9 A semiconductor device comprising: an oxide semiconductor over a substrate; a gate insulating film over the oxide semiconductor; a gate electrode over the gate insulating film; and wherein the gate insulating film is in direct contact with the gate electrode and the oxide semiconductor, wherein the gate insulating film has an oxygen-transmitting property, wherein the gate electrode comprises at least a first region on the gate insulating film and a second region over the first region, wherein the first region and the second region comprise an element of a metal, wherein an oxygen concentration of the first region is lower than an oxygen concentration of the second region, and wherein the oxide semiconductor comprises indium, zinc, and one selected from the group consisting of Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Ga, Y, Zr, Nb, Mo, Sn, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, and W. ### Claim 10 (depends on 9) The semiconductor device according to claim 9, wherein the element is ruthenium. ### Claim 11 (depends on 9) The semiconductor device according to claim 9, wherein the gate electrode substantially consists of ruthenium and oxygen. ### Claim 12 (depends on 9) The semiconductor device according to claim 9, wherein the gate insulating film comprises a layer, and wherein the layer comprises one selected from the group consisting of aluminum oxide, magnesium oxide, silicon oxide, silicon oxynitride, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide. ### Claim 13 (depends on 9) The semiconductor device according to claim 9, further comprising a base insulating film over the substrate, wherein the gate insulating film is in direct contact with the base insulating film. ### Claim 14 (depends on 9) The semiconductor device according to claim 9, wherein a thickness of the gate electrode is greater than or equal to 30 nm, wherein the first region is at a distance of 3 nm from an interface with the gate insulating film, and wherein the second region is at a distance of 15 nm from the interface with the gate insulating film. ### Claim 15 (depends on 9) The semiconductor device according to claim 9, wherein the gate electrode further comprises a third region over the first region and the second region.