# US 2013/0157451 A1 · Methods of forming gate structures for reduced leakage > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0157451 A1 - Document ID: US20130157451A1 - Status: Published application - Kind: A1 - Application number: 13/331,055 - Filed: 2011-12-20 - Published: 2013-06-20 - Earliest claimed: 2011-12-20 - Assignees: Altera Corporation - Inventors: Wuu-Cherng Lin; Fangyun Richter; Che Ta Hsu; Wen Sun Wu - Web page: https://patentgrep.com/patent/US20130157451A1 ## CPC - G06F 30/398: Design verification or optimisation, e.g. using design rule check [DRC], layout versus schematics [LVS] or finite element methods [FEM] (optical proximity correction [OPC] design processes G03F1/36) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Integrated circuits containing transistors are provided. A transistor may include a gate structure formed over an associated well region. The well region may be actively biased and may serve as a body terminal. The well region of one transistor may be formed adjacent to a gate structure of a neighboring transistor. If the gate structure of the neighboring transistor and the well region of the one transistor are both actively biased and are placed close to one another, substantial leakage may be generated. Computer-aided design tools may be used to identify actively driven gate terminals and well regions and may be used to determine whether each gate-well pair is spaced sufficiently far from one another. If a gate-well pair is too close, the design tools may locate an existing gate cut layer and extend the existing gate cut layer to cut the actively driven gate structure. ## Claims ### Claim 1 A method of designing an integrated circuit using integrated circuit design tools implemented on computing equipment, comprising: with the integrated circuit design tools implemented on the computing equipment, identifying at least one transistor well region associated with a first transistor on the integrated circuit; with the integrated circuit design tools implemented on the computing equipment, identifying at least one transistor gate structure associated with a second transistor on the integrated circuit; with the integrated circuit design tools implemented on the computing equipment, computing a distance that separates the transistor well region and the transistor gate structure; and with the integrated circuit design tools implemented on the computing equipment, determining whether the transistor gate structure should be cut into multiple segments based on the computed distance. ### Claim 2 (depends on 1) The method defined in claim 1 wherein identifying the at least one transistor well region comprises identifying at least one transistor well region that is designed to be reversed biased. ### Claim 3 (depends on 1) The method defined in claim 1 wherein the integrated circuit is designed to be supplied with high and low power supply voltages and wherein identifying the at least one transistor well region comprises identifying at least one transistor well region that is designed to receive a voltage that is less than the low power supply voltage. ### Claim 4 (depends on 1) The method defined in claim 1 wherein identifying the at least one transistor gate structure comprises identifying at least one transistor gate structure that is designed to be actively biased. ### Claim 5 (depends on 1) The method defined in claim 1 wherein the integrated circuit is designed to be supplied with high and low power supply voltages and wherein identifying the at least one transistor gate structure comprises identifying at least one transistor gate structure that is designed to receive a voltage that is greater than the low power supply voltage. ### Claim 6 (depends on 1) The method defined in claim 1 further comprising: in response to determining that the computed distance is greater than a predetermined threshold value, registering the transistor gate structure as satisfying design criteria. ### Claim 7 (depends on 6) The method defined in claim 6 further comprising: in response to determining that the computed distance is less than the predetermined threshold value, registering the transistor gate structure as failing design criteria. ### Claim 8 (depends on 5) The method defined in claim 5 further comprising: identifying an existing gate cut layer on the integrated circuit, wherein the gate cut layer serves to specify portions on the integrated circuit that should be devoid of transistor gate structures. ### Claim 9 (depends on 8) The method defined in claim 8 further comprising: extending the gate cut layer to further specify cutting the at least one transistor gate structure into at least first and second segments, wherein at least one of the first and second segments is designed to no longer receive the voltage that is greater than the low power supply voltage. ### Claim 10 A method of designing an integrated circuit using integrated circuit design tools implemented on computing equipment, comprising: with the integrated circuit design tools implemented on the computing equipment, identifying a transistor gate structure on the integrated circuit as being a potential source of leakage; and with the integrated circuit design tools implemented on the computing equipment, identifying an existing gate cut layer in the vicinity of the transistor gate structure, wherein the gate cut layer serves to specify locations at which transistor gate structures should be cut during integrated circuit fabrication processes. ### Claim 11 (depends on 10) The method defined in claim 10 further comprising: reducing leakage between the transistor gate structure and a neighboring transistor well region by extending the existing gate cut layer to cut the transistor gate structure, wherein the transistor gate structure and the neighboring transistor well region each belong to respective transistors on the integrated circuit. ### Claim 12 (depends on 11) The method defined in claim 11 wherein extending the existing gate cut layer to cut the identified transistor gate structure comprises extending the existing gate cut layer to cut the identified transistor gate structure into a first segment that receives a bias voltage and a second segment that does not receive any bias voltage. ### Claim 13 (depends on 11) The method defined in claim 11 wherein extending the existing gate cut layer comprises: identifying a first edge along the transistor gate structure that is closest to the gate cut layer; and identifying a second edge along the transistor gate structure that is opposite to the first edge. ### Claim 14 (depends on 13) The method defined in claim 13 wherein extending the existing gate cut layer further comprises: computing a first region within the transistor gate structure that is defined by the first and second edges, wherein the first region has a length that is designed to be equal to a gate length associated with the transistor gate structure. ### Claim 15 (depends on 14) The method defined in claim 14 wherein extending the existing gate cut layer further comprises: expanding the first region outwards along its length; computing a second region interposed between the expanded first region and the existing gate cut layer; and extending the existing gate cut layer to cover the first and second regions. ### Claim 16 A method of forming an integrated circuit comprising: forming a transistor well region; forming a transistor gate structure; and reducing leakage between the transistor well region and the transistor gate structure by cutting the transistor gate structure into multiple segments. ### Claim 17 (depends on 16) The method defined in claim 16 wherein the transistor well region comprises a reverse biased p-well and wherein the transistor gate structure is actively driven to a high voltage level. ### Claim 18 (depends on 16) The method defined in claim 16 wherein the transistor well region comprises a reverse biased n-well and wherein the transistor gate structure is actively driven to a low voltage level. ### Claim 19 (depends on 16) The method defined in claim 16 wherein the transistor gate structure initially receives a bias voltage and wherein cutting the transistor gate structure into multiple segments comprises cutting the transistor gate structure into a first segment that receives the bias voltage and a second segment that no longer receives the bias voltage. ### Claim 20 (depends on 16) The method defined in claim 16 wherein cutting transistor gate structure into multiple segments comprises etching away a portion of the transistor gate structure.