# US 8,541,837 B2 · Semiconductor field effect power switching device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,541,837 B2 - Document ID: US8541837B2 - Status: Granted - Kind: B2 - Application number: 13/461,198 - Filed: 2012-05-01 - Published: 2012-08-30 - Granted: 2013-09-24 - Earliest claimed: 2008-09-30 - Assignees: Infineon Technologies Austria AG - Applicants: Franz Hirler - Inventors: Franz Hirler - Web page: https://patentgrep.com/patent/US8541837B2 ## CPC - H10D 30/668: {having trench gate electrodes, e.g. UMOS transistors} - H10D 12/481: {having gate structures on slanted surfaces, on vertical surfaces, or in grooves, e.g. trench gate IGBTs} - H10D 30/0295: {using recessing of the source electrodes} - H10D 30/0297: {using recessing of the gate electrodes, e.g. to form trench gate electrodes} - H10D 62/142: {Anode regions of thyristors or collector regions of gated bipolar-mode devices} - H10D 64/117: {Recessed field plates, e.g. trench field plates or buried field plates} - H10D 84/141: {VDMOS having built-in components} - H10D 62/107: {Buried supplementary regions, e.g. buried guard rings (multi-RESURF H10D62/111)} - H10D 62/153: {Impurity concentrations or distributions} - H10D 62/157: {Impurity concentrations or distributions} - H10D 62/393: {Body regions of DMOS transistors or IGBTs (cell layout of DMOS H10D62/127)} - H10D 64/112: {comprising multiple field plate segments} - H10D 64/256: {for lateral devices wherein the source or drain electrodes are recessed in semiconductor bodies (source or drain electrodes of TFTs H10D30/673)} - H10D 64/516: {the thicknesses being non-uniform} - H10D 64/665: {the conductor comprising a layer of elemental metal contacting the insulator, e.g. tungsten or molybdenum (having lateral variation H10D64/671)} - H10D 64/667: {the conductor comprising a layer of alloy material, compound material or organic material contacting the insulator, e.g. TiN workfunction layers (having lateral variation H10D64/671)} - H10P 30/222: {characterised by the angle between the ion beam and the crystal planes or the main crystal surface (characterised by the angle between the ion beam and the mask H10P30/221)} - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A semiconductor device having a semiconductor body, a source metallization arranged on a first surface of the semiconductor body and a trench including a first trench portion and a second trench portion and extending from the first surface into the semiconductor body is provided. The semiconductor body further includes a pn-junction formed between a first semiconductor region and a second semiconductor region. The first trench portion includes an insulated gate electrode which is connected to the source metallization, and the second trench portion includes a conductive plug which is connected to the source metallization and to the second semiconductor region. ## Claims ### Claim 1 A semiconductor device comprising: a source metallization; a first field-effect structure including a source region of a first conductivity type, the source region being electrically connected to the source metallization; a body region of a second conductivity type adjacent to the source region; a first gate electrode and a first insulating region arranged at least between the first gate electrode and the body region, the first gate electrode, the first insulating region and the body region forming a first capacitance, the first capacitance having a first capacitance per unit area; a second field-effect structure including a source region of the first conductivity type; a body region of the second conductivity type adjacent to the source region; an electrode structure and a second insulating region which is, in a first vertical cross-section, arranged at least between the electrode structure and the body region, the source region and the electrode structure being electrically connected to the source metallization; the electrode structure, the second insulating region and the body region forming a second capacitance, the second capacitance having a second capacitance per unit area; the second capacitance per unit area being larger than the first capacitance per unit area; and a body contact region of the second conductivity type which adjoins, in a second vertical cross-section, the electrode structure and the body region of at least one of the first field-effect structure and the second field-effect structure; wherein the body region to which the body contact region adjoins has a first doping concentration; and wherein the body contact region has a second doping concentration which is higher than the first doping concentration. ### Claim 2 (depends on 1) The semiconductor device of claim 1, further comprising a common drift region of the first conductivity type; the common drift region forming a pn-junction with the body regions of the first field-effect structure and the second field-effect structure; wherein the body region of the first field effect structure and the common drift region form a body diode; wherein the second field effect structure forms a MOS-gated diode (MGD) connected in parallel to at least one of the body diode and the first field-effect structure; wherein the total current through the semiconductor device in forward biasing of the body diode is dominated by an unipolar current above an average current flow density in the drift region; and wherein the average current flow density is about 1 mA/mm2. ### Claim 3 (depends on 1) The semiconductor device of claim 1, comprising a plurality of first field-effect structures and second field-effect structures, wherein at least a part of the plurality of first field-effect structures and second field-effect structures are arranged in a regular pattern. ### Claim 4 (depends on 1) The semiconductor device of claim 1, wherein the body region of the first field-effect structure includes a first body sub-region adjoining the first insulating region; wherein the body region of the second field-effect structure includes a second body sub-region adjoining the second insulating region; and wherein the doping concentration of the second body sub-region is lower than the doping concentration of the first body sub-region. ### Claim 5 (depends on 1) The semiconductor device of claim 1, wherein at least one of the first field-effect structures further includes at least one field plate electrically connected to the source metallization. ### Claim 6 (depends on 1) The semiconductor device of claim 1, wherein the first gate electrode includes a material having a first work function, and wherein the second gate electrode includes a material having a second work function which is smaller than the first work function. ### Claim 7 A semiconductor device comprising: a source metallization; a first field-effect structure including a source region of a first conductivity type, the source region being electrically connected to the source metallization; a body region of a second conductivity type adjacent to the source region; a first gate electrode and a first insulating region arranged at least between the first gate electrode and the body region, the first gate electrode, the first insulating region and the body region forming a first capacitance, the first capacitance having a first capacitance per unit area; a second field-effect structure including a source region of the first conductivity type; a body region of the second conductivity type adjacent to the source region; an electrode structure and a second insulating region which is, in a first vertical cross-section, arranged at least between the electrode structure and the body region, the source region and the electrode structure being electrically connected to the source metallization; the electrode structure, the second insulating region and the body region forming a second capacitance, the second capacitance having a second capacitance per unit area; the second capacitance per unit area being larger than the first capacitance per unit area; and a common drift region of the first conductivity type; the common drift region forming a pn-junction with the body regions of the first field-effect structure and the second field-effect structure; wherein the body region of the first field effect structure and the common drift region form a body diode; wherein the second field effect structure forms a MOS-gated diode (MGD) connected in parallel to at least one of the body diode and the first field-effect structure; wherein the total current through the semiconductor device in forward biasing of the body diode is dominated by an unipolar current above an average current flow density in the drift region; and wherein the average current flow density is about 1 mA/mm2. ### Claim 8 (depends on 7) The semiconductor device of claim 7, further comprising a body contact region of the second conductivity type which adjoins, in a second vertical cross-section, the electrode structure and the body region of at least one of the first field-effect structure and the second field-effect structure; wherein the body region to which the body contact region adjoins has a first doping concentration; and wherein the body contact region has a second doping concentration which is higher than the first doping concentration. ### Claim 9 A semiconductor device comprising: a source metallization; a first field-effect structure including a source region of a first conductivity type, the source region being electrically connected to the source metallization; a body region of a second conductivity type adjacent to the source region; a first gate electrode and a first insulating region arranged at least between the first gate electrode and the body region, the first gate electrode, the first insulating region and the body region forming a first capacitance, the first capacitance having a first capacitance per unit area; a second field-effect structure including a source region of the first conductivity type; a body region of the second conductivity type adjacent to the source region; an electrode structure and a second insulating region which is, in a first vertical cross-section, arranged at least between the electrode structure and the body region, the source region and the electrode structure being electrically connected to the source metallization; the electrode structure, the second insulating region and the body region forming a second capacitance, the second capacitance having a second capacitance per unit area; the second capacitance per unit area being larger than the first capacitance per unit area; and wherein the body region of the first field-effect structure includes a first body sub-region adjoining the first insulating region; wherein the body region of the second field-effect structure includes a second body sub-region adjoining the second insulating region; and wherein the doping concentration of the second body sub-region is lower than the doping concentration of the first body sub-region. ### Claim 10 A semiconductor device comprising: a source metallization; a first field-effect structure including a source region of a first conductivity type, the source region being electrically connected to the source metallization; a body region of a second conductivity type adjacent to the source region; a first gate electrode and a first insulating region arranged at least between the first gate electrode and the body region, the first gate electrode, the first insulating region and the body region forming a first capacitance, the first capacitance having a first capacitance per unit area; a second field-effect structure including a source region of the first conductivity type; a body region of the second conductivity type adjacent to the source region; an electrode structure and a second insulating region which is, in a first vertical cross-section, arranged at least between the electrode structure and the body region, the source region and the electrode structure being electrically connected to the source metallization; the electrode structure, the second insulating region and the body region forming a second capacitance, the second capacitance having a second capacitance per unit area; the second capacitance per unit area being larger than the first capacitance per unit area; and wherein at least one of the first field-effect structures further includes at least one field plate electrically connected to the source metallization. ### Claim 11 A semiconductor device comprising: a source metallization; a first field-effect structure including a source region of a first conductivity type, the source region being electrically connected to the source metallization; a body region of a second conductivity type adjacent to the source region; a first gate electrode and a first insulating region arranged at least between the first gate electrode and the body region, the first gate electrode, the first insulating region and the body region forming a first capacitance, the first capacitance having a first capacitance per unit area; a second field-effect structure including a source region of the first conductivity type; a body region of the second conductivity type adjacent to the source region; an electrode structure and a second insulating region which is, in a first vertical cross-section, arranged at least between the electrode structure and the body region, the source region and the electrode structure being electrically connected to the source metallization; the electrode structure, the second insulating region and the body region forming a second capacitance, the second capacitance having a second capacitance per unit area; the second capacitance per unit area being larger than the first capacitance per unit area; and wherein the first gate electrode includes a material having a first work function, and wherein the second gate electrode includes a material having a second work function which is smaller than the first work function.