# US 12,002,806 B2 · Reverse conducting semiconductor device and method for manufacturing reverse conducting semiconductor device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,002,806 B2 - Document ID: US12002806B2 - Status: Granted - Kind: B2 - Application number: 17/402,842 - Filed: 2021-08-16 - Published: 2022-04-21 - Granted: 2024-06-04 - Earliest claimed: 2020-10-21 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Koichi Nishi; Shinya Soneda; Takahiro Nakatani - Web page: https://patentgrep.com/patent/US12002806B2 ## CPC - H10D 84/811: {Combinations of field-effect devices and one or more diodes, capacitors or resistors} - H10D 8/00: Diodes (variable-capacitance diodes H10D1/64; gated diodes H10D12/00) - H10D 8/045: {of PN junction diodes} - H10D 8/422: {PN diodes having the PN junctions in mesas} - H10D 12/038: {having a recessed gate, e.g. trench-gate IGBTs} - H10D 12/481: {having gate structures on slanted surfaces, on vertical surfaces, or in grooves, e.g. trench gate IGBTs} - H10D 62/106: {having supplementary regions doped oppositely to or in rectifying contact with regions of the semiconductor bodies, e.g. guard rings with PN or Schottky junctions} - H10D 62/126: {Top-view geometrical layouts of the regions or the junctions} - H10D 62/127: {of cellular field-effect devices, e.g. multicellular DMOS transistors or IGBTs} - H10D 64/117: {Recessed field plates, e.g. trench field plates or buried field plates} - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES ## Abstract The semiconductor substrate has a first principal surface and a second principal surface. The base contact layer is arranged between the base layer and the first principal surface, and forms a part of the first principal surface. The anode contact region is arranged between the anode layer and the first principal surface, forms a part of the first principal surface, and has a second conductivity type impurity concentration peak value higher than that of the anode layer. The anode contact region includes a first anode contact layer having a lower net concentration and a higher first conductivity type impurity concentration than the base contact layer. ## Claims ### Claim 1 A reverse conducting semiconductor device having an insulated gate bipolar transistor region and a diode region, the reverse conducting semiconductor device comprising: a semiconductor substrate included in the insulated gate bipolar transistor region and the diode region, the semiconductor substrate having a first principal surface and a second principal surface opposite to the first principal surface, the semiconductor substrate including a drift layer extending over the insulated gate bipolar transistor region and the diode region and having a first conductivity type, a base layer arranged between the drift layer and the first principal surface in the insulated gate bipolar transistor region, the base layer having a second conductivity type different from the first conductivity type, an emitter layer arranged between the base layer and the first principal surface in the insulated gate bipolar transistor region, the emitter layer having the first conductivity type, a base contact layer arranged between the base layer and the first principal surface in the insulated gate bipolar transistor region, the base contact layer forming a part of the first principal surface, the base contact layer having the second conductivity type, a collector layer arranged between the drift layer and the second principal surface in the insulated gate bipolar transistor region, the collector layer having the second conductivity type, an anode layer arranged between the drift layer and the first principal surface in the diode region, the anode layer having the second conductivity type, an anode contact region arranged between the anode layer and the first principal surface in the diode region, the anode contact region forming a part of the first principal surface, the anode contact region having a second conductivity type impurity concentration peak value higher than that of the anode layer, the anode contact region having the second conductivity type, and a cathode layer arranged between the drift layer and the second principal surface in the diode region, the cathode layer having the first conductivity type; an insulated gate structure for forming, with the base layer, a channel for controlling an electrical path between the emitter layer and the drift layer; a collector electrode electrically connected to the collector layer and the cathode layer; and an emitter electrode in contact with the base contact layer and the anode contact region, wherein the anode contact region includes a first anode contact layer having a lower net concentration and a higher first conductivity type impurity concentration than the base contact layer. ### Claim 2 (depends on 1) The reverse conducting semiconductor device according to claim 1, wherein the anode contact region includes a second anode contact layer, and wherein the first anode contact layer has a lower net concentration than the second anode contact layer. ### Claim 3 (depends on 2) The reverse conducting semiconductor device according to claim 2, wherein the first anode contact layer has a higher first conductivity type impurity concentration than the second anode contact layer. ### Claim 4 (depends on 1) The reverse conducting semiconductor device according to claim 1, wherein the first principal surface does not have the first conductivity type in the diode region. ### Claim 5 (depends on 1) The reverse conducting semiconductor device according to claim 1, wherein the anode layer forms a part of the first principal surface. ### Claim 6 (depends on 1) The reverse conducting semiconductor device according to claim 1, wherein a net peak concentration of the anode layer is 1×1016/cm3 or more. ### Claim 7 (depends on 1) The reverse conducting semiconductor device according to claim 1, wherein a net peak concentration of the first anode contact layer is 1×1018/cm3 or more. ### Claim 8 (depends on 1) The reverse conducting semiconductor device according to claim 1, wherein in the diode region, the semiconductor substrate has a minimum value of a net concentration profile in a thickness direction at a depth position between the first anode contact layer and the anode layer. ### Claim 9 (depends on 1) The reverse conducting semiconductor device according to claim 1, wherein the first anode contact layer has a peak value of a net concentration profile in a thickness direction at a depth position away from the first principal surface. ### Claim 10 (depends on 1) The reverse conducting semiconductor device according to claim 1, wherein the semiconductor substrate includes an interposing layer having a first conductivity type between the first anode contact layer and the anode layer in a thickness direction in the diode region. ### Claim 11 (depends on 1) A method for manufacturing a reverse conducting semiconductor device for manufacturing the reverse conducting semiconductor device according to claim 1, the method comprising: performing first conductivity type impurity doping of the emitter layer by ion implantation into the first principal surface of the semiconductor substrate; and performing first conductivity type impurity doping of the first anode contact layer by ion implantation into the first principal surface of the semiconductor substrate, wherein the first conductivity type impurity doping of the emitter layer and the first conductivity type impurity doping of the first anode contact layer are simultaneously performed as a common first conductivity type impurity doping. ### Claim 12 (depends on 11) The method for manufacturing a reverse conducting semiconductor device according to claim 11, further comprising: performing second conductivity type impurity doping of the base contact layer by ion implantation into the first principal surface of the semiconductor substrate; and performing second conductivity type impurity doping of the first anode contact layer by ion implantation into the first principal surface of the semiconductor substrate, wherein the second conductivity type impurity doping of the base contact layer and the second conductivity type impurity doping of the first anode contact layer are simultaneously performed as a common second conductivity type impurity doping. ### Claim 13 (depends on 12) The method for manufacturing a reverse conducting semiconductor device according to claim 12, wherein an implantation amount of first conductivity type impurity ions per unit area in the common first conductivity type impurity doping is lower than an implantation amount of second conductivity type impurity ions per unit area in the common second conductivity type impurity doping.