# US 8,569,742 B2 · Organic field-effect transistor and semiconductor device including the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,569,742 B2 - Document ID: US8569742B2 - Status: Granted - Kind: B2 - Application number: 11/792,232 - Filed: 2005-12-05 - Published: 2008-02-28 - Granted: 2013-10-29 - Earliest claimed: 2004-12-06 - Assignees: Semiconductor Energy Laboratory Co., Ltd. - Applicants: Nobuharu Ohsawa; Yoshiharu Hirakata; Shinobu Furukawa - Inventors: Nobuharu Ohsawa; Yoshiharu Hirakata; Shinobu Furukawa - Web page: https://patentgrep.com/patent/US8569742B2 ## CPC - H10K 10/84: Ohmic electrodes, e.g. source or drain electrodes - H10K 59/125: including organic TFTs [OTFT] - H10K 10/464: {Lateral top-gate IGFETs comprising only a single gate} - H10K 10/466: {Lateral bottom-gate IGFETs comprising only a single gate} - H10K 59/123: Connection of the pixel electrodes to the thin film transistors [TFT] - H10K 71/191: {characterised by provisions for the orientation or alignment of the layer to be deposited} - H10K 77/111: {Flexible substrates} - H10K 85/621: {Aromatic anhydride or imide compounds, e.g. perylene tetra-carboxylic dianhydride or perylene tetracarboxylic di-imide} - H10K 85/623: {containing five rings, e.g. pentacene} - H10K 85/631: {Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine} - Y02E 10/549: Organic PV cells - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract It is an object to provide an electrode for an organic field-effect transistor having a semiconductor layer formed of an organic semiconductor material (in the present invention, referred to as an organic field-effect transistor), which can reduce the energy barrier at an interface with the semiconductor layer. A composite layer including an organic compound and a metal oxide is used for the electrode for the organic field-effect transistor, in other words the composite layer is used for at least a part of either a source electrode or a drain electrode in the organic field-effect transistor. ## Claims ### Claim 1 A semiconductor device comprising: an organic field-effect transistor over a substrate, the organic field-effect transistor comprising a semiconductor layer including an organic semiconductor material, and a source electrode and a drain electrode formed in contact with the semiconductor layer, wherein the source electrode and the drain electrode each include a same composite layer made of a mixture of an organic compound and a metal oxide. ### Claim 2 (depends on 1) The semiconductor device according to claim 1, wherein the organic compound is an aromatic amine compound. ### Claim 3 (depends on 1) The semiconductor device according to claim 1, wherein the metal oxide is a transition metal oxide. ### Claim 4 (depends on 1) The semiconductor device according to claim 1, wherein the metal oxide is selected from the group consisting of titanium oxide, zirconium oxide, hafnium oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, rhenium oxide, and ruthenium oxide. ### Claim 5 (depends on 1) The semiconductor device according to claim 1, wherein the organic semiconductor material is a same material as the organic compound. ### Claim 6 (depends on 1) The semiconductor device according to claim 1, wherein the organic field-effect transistor further comprises a second layer including a material selected from the group consisting of an alkali metal, an alkaline earth metal, an alkali metal compound, and an alkaline earth metal compound, and the second layer is provided to be in contact with the composite layer. ### Claim 7 (depends on 1) The semiconductor device according to claim 1, wherein the organic field-effect transistor further comprises a conductive layer provided to be in contact with the composite layer. ### Claim 8 (depends on 1) The semiconductor device according to claim 1, wherein the semiconductor device is incorporated into an electronic device selected from the group consisting of a liquid crystal display device, a light emitting display device, a mobile phone set, a television set, and an ID card. ### Claim 9 (depends on 1) The semiconductor device according to claim 1, wherein the one of the source electrode and the drain electrode further includes a second layer including a material selected from the group consisting of an alkali metal, an alkaline earth metal, an alkali metal compound, and an alkaline earth metal compound. ### Claim 10 (depends on 1) The semiconductor device according to claim 1, further comprising a second layer including a material selected from the group consisting of an alkali metal, an alkaline earth metal, an alkali metal compound, and an alkaline earth metal compound, and wherein the second layer is interposed between the composite layer and the organic semiconductor material. ### Claim 11 An organic field-effect transistor comprising: a semiconductor layer over a substrate, the semiconductor layer including an organic semiconductor material, and a source electrode and a drain electrode formed in contact with the semiconductor layer, wherein the source electrode and the drain electrode each include an electrically conductive layer and a same composite layer made of a mixture of an organic compound and a metal oxide. ### Claim 12 (depends on 11) The organic field-effect transistor according to claim 11, wherein the organic compound is an aromatic amine compound. ### Claim 13 (depends on 11) The organic field-effect transistor according to claim 11, wherein the metal oxide is a transition metal oxide. ### Claim 14 (depends on 11) The organic field-effect transistor according to claim 11, wherein the metal oxide is selected from the group consisting of titanium oxide, zirconium oxide, hafnium oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, rhenium oxide, and ruthenium oxide. ### Claim 15 (depends on 11) The organic field-effect transistor according to claim 11, wherein the organic semiconductor material is a same material as the organic compound. ### Claim 16 (depends on 11) The organic field-effect transistor according to claim 11, wherein the organic field-effect transistor further comprises a second layer including a material selected from the group consisting of an alkali metal, an alkaline earth metal, an alkali metal compound, and an alkaline earth metal compound, and the second layer is provided to be in contact with the composite layer. ### Claim 17 (depends on 11) The organic field-effect transistor according to claim 11, wherein the organic field-effect transistor further comprises a conductive layer provided to be in contact with the composite layer. ### Claim 18 (depends on 11) The organic field-effect transistor according to claim 11, wherein the organic field-effect transistor is incorporated into an electronic device selected from the group consisting of a liquid crystal display device, a light emitting display device, a mobile phone set, a television set, and an ID card. ### Claim 19 (depends on 11) The organic field-effect transistor according to claim 11, wherein the one of the source electrode and the drain electrode further includes a second layer including a material selected from the group consisting of an alkali metal, an alkaline earth metal, an alkali metal compound, and an alkaline earth metal compound. ### Claim 20 (depends on 11) The organic field-effect transistor according to claim 11, further comprising a second layer including a material selected from the group consisting of an alkali metal, an alkaline earth metal, an alkali metal compound, and an alkaline earth metal compound, and wherein the second layer is interposed between the composite layer and the organic semiconductor material. ### Claim 21 A semiconductor device comprising: an organic field-effect transistor over a substrate, the organic field-effect transistor comprising a semiconductor layer including an organic semiconductor material, and a source electrode and a drain electrode formed in contact with the semiconductor layer, wherein the source electrode and the drain electrode each include: an electrically conductive layer; and a composite layer made of a mixture of an organic compound and a metal oxide, the composite layer being in direct contact with the organic semiconductor layer. ### Claim 22 (depends on 21) An electronic device incorporating the semiconductor device according to claim 21. ### Claim 23 A semiconductor device comprising: an organic field-effect transistor over a substrate, the organic field-effect transistor comprising a semiconductor layer including an organic semiconductor material, and a source electrode and a drain electrode formed in contact with the semiconductor layer, wherein the source electrode and the drain electrode each include: an electrically conductive layer; a composite layer made of a mixture of an organic compound and a metal oxide, and a second layer including a material selected from the group consisting of an alkali metal, an alkaline earth metal, an alkali metal compound, and an alkaline earth metal compound, the second layer being interposed between the organic semiconductor layer and the composite layer, and in direct contact with the organic semiconductor layer. ### Claim 24 (depends on 23) An electronic device incorporating the semiconductor device according to claim 23.