# US 8,772,864 B2 · Trench MOSFET device and method for fabricating the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,772,864 B2 - Document ID: US8772864B2 - Status: Granted - Kind: B2 - Application number: 13/807,612 - Filed: 2011-11-29 - Published: 2013-04-18 - Granted: 2014-07-08 - Earliest claimed: 2010-12-17 - Assignees: Csmc Technologies Fab1 Co., Ltd.; Csmc Technologies Fab2 Co., Ltd. - Applicants: Jiakun Wang - Inventors: Jiakun Wang - Web page: https://patentgrep.com/patent/US8772864B2 ## CPC - H10D 30/63: Vertical IGFETs (H10D30/66 {, H10D30/6728, H10D30/689, H10D30/693} take precedence) - H10D 30/025: {of vertical IGFETs (of VDMOS H10D30/0291; of vertical TFTs H10D30/0318)} - H10D 64/513: {within recesses in the substrate, e.g. trench gates, groove gates or buried gates} - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES ## Abstract A trench Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) device is disclosed. The trench MOSFET device includes a substrate, a body region, a source region, a dielectric layer, a metal layer, a contact hole, and a trench structure. The substrate includes a substrate layer and an epitaxial layer formed on the substrate layer; the body region is formed in the epitaxial layer; and the source region is formed in the body region of the epitaxial layer. Further, the dielectric layer is formed on the epitaxial layer; the metal layer is formed on the dielectric layer; and the contact hole is formed in the dielectric layer to connect the source region with the metal layer. In addition, the trench structure is formed in the epitaxial layer, and the trench structure includes a first trench that is a pectinate trench including a plurality of tooth trenches and a bar trench interconnecting the plurality of tooth trenches. ## Claims ### Claim 1 A trench Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) device, comprising: a substrate including a substrate layer and an epitaxial layer formed on the substrate layer; a body region formed in the epitaxial layer; a source region formed in the body region of the epitaxial layer; a dielectric layer formed on the epitaxial layer; a metal layer formed on the dielectric layer; a contact hole formed in the dielectric layer to connect the source region with the metal layer; and a trench structure formed in the epitaxial layer, wherein the trench structure includes a first trench that is a pectinate trench including a plurality of tooth trenches and a bar trench interconnecting the plurality of tooth trenches, wherein a total length of all of the plurality of tooth trenches corresponds to a channel width of the MOSFET device, and wherein the channel width is equal to a contact hole side outer perimeter of the trench structure. ### Claim 2 (depends on 1) The trench MOSFET device according to claim 1, wherein the trench structure further includes: a second trench in a shape of one of a square, a hexagon, and a circle, the second trench being connected to the first trench. ### Claim 3 (depends on 2) The trench MOSFET device according to claim 2, wherein: a length of middle tooth trenches is less than a length of an edge tooth trenches such that tooth trenches from different cells can be distinguished. ### Claim 4 (depends on 1) The trench MOSFET device according to claim 1, wherein the trench structure further includes: a second trench that is also a pectinate trench and arranged symmetrically with the first trench to form a symmetric trench pair along a symmetric line; and the contract hole is located on the symmetric line. ### Claim 5 (depends on 1) The trench MOSFET device according to claim 1, wherein the trench structure further includes: a second trench that is also a pectinate trench and arranged asymmetrically with the first trench to form an asymmetric trench pair with the plurality of tooth trenches of the first trench meshing with the plurality of tooth trenches of the second trench. ### Claim 6 (depends on 1) The trench MOSFET device according to claim 1, wherein: a total number of the plurality of tooth trenches is six; and the contact hole is located in the middle of the plurality of tooth trenches. ### Claim 7 (depends on 1) The trench MOSFET device according to claim 1, wherein: the trench structure is filled with gate oxide and polysilicon to form a gate region of the MOSFET device controlling a channel of the MOSFET device. ### Claim 8 (depends on 1) The trench MOSFET device according to claim 1, further including: a drain formed on a back side of the substrate layer. ### Claim 9 A method for fabricating a trench Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) device, comprising: providing a substrate including a substrate layer and an epitaxial layer formed on the substrate layer; forming a trench structure in the epitaxial layer using a trench pattern, wherein the trench pattern includes a first pattern for a first trench that is a pectinate trench including a plurality of tooth trenches and a bar trench interconnecting the plurality of tooth trenches, wherein a total length of all of the plurality of tooth trenches corresponds to a channel width of the MOSFET device, and wherein the channel width is equal to a contact hole side outer perimeter of the trench structure; forming a body region in the epitaxial layer; forming a source region in the body region of the epitaxial layer; forming a dielectric layer on the epitaxial layer; forming a contact hole formed in the dielectric layer; and forming a metal layer on the dielectric layer, wherein the contact hole is filled with metal material to connect the source region with the metal layer. ### Claim 10 (depends on 9) The method according to claim 9, wherein the trench pattern further includes: a second pattern for a second trench in a shape of one of a square, a hexagon, and a circle, the second trench being connected to the first trench. ### Claim 11 (depends on 9) The method according to claim 9, wherein the trench pattern further includes: a second pattern for a second trench that is also a pectinate trench and arranged symmetrically with the first trench to form a symmetric trench pair along a symmetric line; and the contract hole is located on the symmetric line. ### Claim 12 (depends on 9) The method according to claim 9, wherein the trench pattern further includes: a second pattern for a second trench that is also a pectinate trench and arranged asymmetrically with the first trench to form an asymmetric trench pair with the plurality of tooth trenches of the first trench meshing with the plurality of tooth trenches of the second trench. ### Claim 13 (depends on 9) The method according to claim 9, wherein: a total number of the plurality of tooth trenches is six; and the contact hole is located in the middle of the plurality of tooth trenches. ### Claim 14 (depends on 9) The method according to claim 9, further including: filling the trench structure with gate oxide and polysilicon to form a gate region of the MOSFET device controlling a channel of the MOSFET device. ### Claim 15 (depends on 1) The trench MOSFET device according to claim 1, wherein the trench structure further includes a second trench, the second trench including an opened square trench connecting with the bar trench of the first trench. ### Claim 16 (depends on 2) The trench MOSFET device according to claim 2, wherein the second trench connects with the bar trench of the first trench. ### Claim 17 (depends on 1) The trench MOSFET device according to claim 1, wherein the trench structure further includes a second trench, the second trench including a portion of a square trench connecting with the bar trench of the first trench. ### Claim 18 (depends on 4) The trench MOSFET device according to claim 4, wherein the second trench is arranged symmetrically mirroring with the first trench. ### Claim 19 (depends on 4) The trench MOSFET device according to claim 4, wherein each of the first trench and the second trench further includes an additional trench having a shape of one of a square, a hexagon, and a circle, the additional trench connecting with the bar trench of each of the first trench and the second trench.