# US 12,183,818 B2 · Power semiconductor device and manufacturing method therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,183,818 B2 - Document ID: US12183818B2 - Status: Granted - Kind: B2 - Application number: 17/417,677 - Filed: 2019-12-23 - Published: 2022-04-14 - Granted: 2024-12-31 - Earliest claimed: 2018-12-24 - Assignees: Southeast University; Csmc Technologies Fab2 Co., Ltd. - Applicants: Southeast University; Csmc Technologies Fab2 Co., Ltd. - Inventors: Weifeng Sun; Rongcheng Lou; Kui Xiao; Feng Lin; Jiaxing Wei; Sheng Li; Siyang Liu; Shengli Lu; Longxing Shi - Web page: https://patentgrep.com/patent/US12183818B2 ## CPC - H10D 84/146: {the built-in components being Schottky barrier diodes} - H10D 12/031: {of IGBTs} - H10D 30/0291: {of vertical DMOS [VDMOS] FETs} - H10D 62/126: {Top-view geometrical layouts of the regions or the junctions} - H10D 62/393: {Body regions of DMOS transistors or IGBTs (cell layout of DMOS H10D62/127)} - H10D 62/8325: {Silicon carbide} - H10P 30/22: using masks - H10D 8/60: Schottky-barrier diodes - H10D 62/107: {Buried supplementary regions, e.g. buried guard rings (multi-RESURF H10D62/111)} - H10D 64/64: Electrodes comprising a Schottky barrier to a semiconductor - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A power semiconductor device includes: a substrate; drain metal; a drift region; a base region; a gate structure; a first conductive type doped region contacting the base region on the side of the base region distant from the gate structure; a source region provided in the base region and between the first conductive type doped region and the gate structure; contact metal that is provided on the first conductive type doped region and forms a contact barrier having rectifying characteristics together with the first conductive type doped region below; and source metal wrapping the contact metal and contacting the source region. ## Claims ### Claim 1 A power semiconductor device, comprising: a substrate of a first conductivity type; a drain metal disposed on a first surface of the substrate; a drift region of the first conductivity type and disposed on a second surface of the substrate, the second surface being opposite to the first surface; a base region of a second conductivity type and disposed in the drift region; the first conductivity type and the second conductivity type being opposite conductivity types; a gate structure comprising a gate dielectric layer on the drift region and a gate on the gate dielectric layer, the gate structure extending above the base region; a first-conductivity-type doping region in contact with the base region on one side of the base region away from the gate structure; a source region of the first conductivity type and disposed in the base region and between the first-conductivity-type doping region and the gate structure; a contact metal disposed on the first-conductivity-type doping region and forming a contact barrier having rectification characteristics with the first-conductivity-type doping region below, wherein a dimension of the contact metal in a first direction is greater than a dimension of the first-conductivity-type doping region in the first direction, such that the contact metal extends to a position above the base region next to the first-conductivity-type doping region and not reaching the source region, the first direction being a wiring direction between the gate and the contact metal; and a source metal wrapping the contact metal and in contact with the source region. ### Claim 2 (depends on 1) The power semiconductor device according to claim 1, further comprising a body contact region of the second conductivity type disposed in the base region and between the source region and the first-conductivity-type doping region, the contact metal being in contact with the body contact region. ### Claim 3 (depends on 1) The power semiconductor device according to claim 1, further comprising a second-conductivity-type doping region disposed in the drift region, the second-conductivity-type doping region being disposed below the base region and the first-conductivity-type doping region and being in contact with the base region and the first-conductivity-type doping region. ### Claim 4 (depends on 3) The power semiconductor device according to claim 3, wherein the second-conductivity-type doping region consists of a plurality of sub-doping regions distributed at intervals in a second direction, the second direction is perpendicular to the first direction, and a plane formed by the second direction and the first direction is a horizontal plane. ### Claim 5 (depends on 4) The power semiconductor device according to claim 4, wherein the sub-doping regions are of equal size and distributed at equal intervals in the second direction, and a ratio of a dimension of the interval in the second direction to a dimension of the sub-doping regions in the second direction is 0.2-0.6:1. ### Claim 6 (depends on 3) The power semiconductor device according to claim 3, wherein a dimension ratio of a part of the second-conductivity-type doping region below the base region to a part of the second-conductivity-type doping region below the first-conductivity-type doping region in the first direction is 0.2-0.4:1. ### Claim 7 (depends on 1) The power semiconductor device according to claim 1, wherein a doping concentration of the first-conductivity-type doping region is greater than a doping concentration of the drift region and less than a doping concentration of the source region. ### Claim 8 (depends on 1) The power semiconductor device according to claim 1, wherein the contact metal is made of at least one selected from the group consisting of gold, titanium, and nickel. ### Claim 9 (depends on 1) The power semiconductor device according to claim 1, wherein the contact barrier having rectification characteristics is a schottky barrier. ### Claim 10 (depends on 1) The power semiconductor device according to claim 1, wherein the first conductivity type is N-type, and the second conductivity type is P-type. ### Claim 11 (depends on 1) The power semiconductor device according claim 1, wherein the power semiconductor device is a silicon carbide power semiconductor device. ### Claim 12 A method of manufacturing a power semiconductor device, comprising: acquiring a substrate provided with a drift region, the drift region being formed on one surface of the substrate, and the substrate and the drift region being of a first conductivity type; doping second-conductivity-type ions to form a base region of a second conductivity type in the drift region; the first conductivity type and the second conductivity type being opposite conductivity types; doping first-conductivity-type ions to form a first-conductivity-type doping region in the drift region that is in contact with the base region; doping the first-conductivity-type ions to form a source region of the first conductivity type in the base region; forming a contact metal on the first-conductivity-type doping region, the contact metal forming a contact barrier having rectification characteristics with the first-conductivity-type doping region below, and the contact metal extending toward the source region and above the base region not reaching the source region; forming a gate structure on the drift region, the gate structure comprising a gate dielectric layer on the drift region and a gate on the gate dielectric layer, the gate structure extending above one side of the base region opposite to the first-conductivity-type doping region; and forming a source metal wrapping the contact metal, the source metal being in contact with the source region. ### Claim 13 (depends on 12) The method according to claim 12, wherein after the step of acquiring the substrate provided with the drift region and prior to the step of doping second-conductivity-type ions to form the base region of the second conductivity type in the drift region, the method further comprises a step of forming a second-conductivity-type doping region in the drift region, the second-conductivity-type doping region being formed below the base region and the first-conductivity-type doping region and being in contact with the base region and the first-conductivity-type doping region. ### Claim 14 (depends on 12) The method according to claim 12, wherein after the step of doping second-conductivity-type ions to form the base region of the second conductivity type in the drift region and prior to the step of forming the contact metal on the first-conductivity-type doping region, the method further comprises a step of forming a body contact region in the base region, the body contact region being formed between the source region and the first-conductivity-type doping region. ### Claim 15 (depends on 13) The method according to claim 13, wherein the step of forming the second-conductivity-type doping region in the drift region comprises: after photolithography, forming the second-conductivity-type doping region distributed at intervals in the drift region by aluminum ion implantation by using a photoresist as a mask. ### Claim 16 (depends on 12) The method according to claim 12, wherein acquiring the substrate provided with the drift region comprises: extending an N-type epitaxial layer on a surface of an N-type substrate, serving the N-type epitaxial layer as the drift region. ### Claim 17 (depends on 13) The method according to claim 13, wherein doping first-conductivity-type ions to form the first-conductivity-type doping region in the drift region that is in contact with the base region comprises: after the photoresist is removed, performing photolithography again, and then forming the first-conductivity-type doping region in contact with the base region in the drift region by nitrogen ion implantation. ### Claim 18 (depends on 12) The method according to claim 12, wherein the contact metal is made of at least one selected from the group consisting of gold, titanium, and nickel. ### Claim 19 (depends on 12) The method according to claim 12, wherein the contact barrier having rectification characteristics is a schottky barrier. ### Claim 20 (depends on 12) The method according to claim 12, wherein forming the gate structure on the drift region comprises: growing a gate oxide layer after the photoresist is removed, and then depositing polysilicon to form a polysilicon gate by photolithography and etching.