Infineon Technologies Ag

Michael Hell

Caspar Leendertz

Rudolf Elpelt

Dethard Peters

Thomas Basler

Hans-Joachim Schulze

Jens Peter Konrath

Thomas Aichinger

Bernd Zippelius

Shiqin Niu

Paul Ellinghaus

Konrad Schraml

Ralf Siemieniec

Romain Esteve

Wolfgang Bergner

Daniel Kueck

Thomas Ganner

Moriz Jelinek

Kristijan Luka Mletschnig

Andreas Hürner

A power semiconductor device is proposed. The vertical power semiconductor device includes a silicon carbide (SiC) semiconductor body having a first surface and a second surface opposite to the first surface. The SiC semiconductor body includes a transistor cell area comprising gate structures, a gate pad area, and an interconnection area electrically coupling a gate electrode of the gate structures and a gate pad of the gate pad area via a gate interconnection. The vertical power semiconductor device further includes a source or emitter electrode. The vertical power semiconductor device further includes a first interlayer dielectric comprising a first interface to the source or emitter electrode and a second interface to at least one of the gate electrode, or the gate interconnection, or the gate pad, and wherein a conduction band offset at the first interface ranges from 1 eV to 2.5 eV.

Vertical power semiconductor device including silicon carbide (sic) semiconductor body

A silicon carbide device includes: a transistor cell having a stripe-shaped trench gate structure extending from a first surface into a silicon carbide body, the gate structure having a gate length along a lateral first direction, a bottom surface and a first gate sidewall of the gate structure being connected via a first bottom edge of the gate structure; at least one source region of a first conductivity type in contact with the first gate sidewall; and a shielding region of a second conductivity type in contact with the first bottom edge of the gate structure across at least 20% of the gate length. No source regions of the first conductivity type are in contact with a second gate sidewall of the gate structure.

Silicon carbide device with a stripe-shaped trench gate structure

A semiconductor device includes a silicon carbide semiconductor body. A first shielding region of a first conductivity type is connected to a first contact at a first surface of the silicon carbide semiconductor body. A current spread region of a second conductivity type is connected to a second contact at a second surface of the silicon carbide semiconductor body. A doping concentration profile of the current spread region includes peaks along a vertical direction perpendicular to the first surface. A doping concentration of one peak or one peak-group of the peaks is at least 50% higher than a doping concentration of any other peak of the current spread region. A vertical distance between the one peak or the one peak-group of the current spread region and the first surface is larger than a second vertical distance between the first surface and a maximum doping peak of the first shielding region.

Semiconductor device including current spread region

A semiconductor device includes: a SiC substrate; a device structure in or on the SiC substrate and subject to an electric field during operation of the semiconductor device; a current-conduction region of a first conductivity type in the SiC substrate adjoining the device structure; and a shielding region of a second conductivity type laterally adjacent to the current-conduction region and configured to at least partly shield the device structure from the electric field. The shielding region has a higher net doping concentration than the current-conduction region, and has a length (L) measured from a first position which corresponds to a bottom of the device structure to a second position which corresponds to a bottom of the shielding region. The current-conduction region has a width (d) measured between opposing lateral sides of the current-conduction region, and L/d is in a range of 1 to 10.

SiC devices with shielding structure

In an example, a substrate is oriented to a target axis, wherein a residual angular misalignment between the target axis and a preselected crystal channel direction in the substrate is within an angular tolerance interval. Dopant ions are implanted into the substrate using an ion beam that propagates along an ion beam axis. The dopant ions are implanted at implant angles between the ion beam axis and the target axis. The implant angles are within an implant angle range. A channel acceptance width is effective for the preselected crystal channel direction. The implant angle range is greater than 80% of a sum of the channel acceptance width and twofold the angular tolerance interval. The implant angle range is smaller than 500% of the sum of the channel acceptance width and twofold the angular tolerance interval.

Ion beam implantation method and semiconductor device

A method of producing a silicon carbide (SiC) device includes: forming a stripe-shaped trench gate structure that extends from a first surface of a SiC body into the SiC body, the gate structure having a gate length along a lateral first direction, a bottom surface and a first gate sidewall of the gate structure being connected via a first bottom edge of the gate structure; forming at least one source region of a first conductivity type; and forming a shielding region of a second conductivity type in contact with the first bottom edge of the gate structure across at least 20% of the gate length. Forming the shielding region includes: forming a deep shielding portion; and forming a top shielding portion between the first surface and the deep shielding portion, the top shielding portion being in contact with the first bottom edge.

Method of producing a silicon carbide device with a trench gate

According to an embodiment of a semiconductor device, the device includes: a plurality of device cells formed in a semiconductor substrate, each device cell including a transistor structure and a Schottky diode structure; and a superjunction structure that includes alternating regions of a first conductivity type and of a second conductivity type formed in the semiconductor substrate. For each transistor structure, a channel region of the transistor structure and a Schottky metal region of an adjacent one of the Schottky diode structures are interconnected by semiconductor material of the first conductivity type without interruption by any of the regions of the second conductivity type of the superjunction structure, the semiconductor material of the first conductivity type including one or more of the regions of the first conductivity type of the superjunction structure.

Power transistor with integrated Schottky diode

A semiconductor component includes: gate structures extending from a first surface into an SiC semiconductor body; a drift zone of a first conductivity type formed in the SiC semiconductor body; first mesas and second mesas arranged between the gate structures in the SiC semiconductor body; body areas of a second conductivity type arranged in the first mesas and the second mesas, the body areas each adjoining a first side wall of one of the gate structures; first shielding areas of the second conductivity type adjoining a second side wall of one of the gate structures; second shielding areas of the second conductivity type adjoining the body areas in the second mesas; and diode areas of the conductivity type of the drift zone, the diode areas forming Schottky contacts with a load electrode between the first shielding areas and the second shielding areas.

Silicon carbide field-effect transistor including shielding areas

A silicon carbide device includes a stripe-shaped trench gate structure extending from a first surface into a silicon carbide body. The gate structure has a gate length along a lateral first direction. A bottom surface and an active first gate sidewall of the gate structure are connected via a first bottom edge of the gate structure. The silicon carbide device further includes at least one source region of a first conductivity type. A shielding region of a second conductivity type is in contact with the first bottom edge of the gate structure across at least 20% of the gate length.

Silicon carbide device with trench gate

A semiconductor device includes: a SiC substrate; a device structure in or on the SiC substrate and subject to an electric field during operation of the semiconductor device; a current-conduction region of a first conductivity type in the SiC substrate below and adjoining the device structure; and a shielding region of a second conductivity type laterally adjacent to the current-conduction region and configured to at least partly shield the device structure from the electric field. The shielding region has a higher net doping concentration than the current-conduction region, and has a length (L) measured from a first position which corresponds to a bottom of the device structure to a second position which corresponds to a bottom of the shielding region. The current-conduction region has a width (d) measured between opposing lateral sides of the current-conduction region, and L/d is in a range of 1 to 10.

Shielding structure for SiC devices

A semiconductor component has a gate structure that extends from a first surface into an SiC semiconductor body. A body area in the SiC semiconductor body adjoins a first side wall of the gate structure. A first shielding area and a second shielding area of the conductivity type of the body area have at least twice as high a level of doping as the body area. A diode area forms a Schottky contact with a load electrode between the first shielding area and the second shielding area.

A SiC substrate of a semiconductor device includes: a drift region of a first conductivity type; a body region of a second conductivity type having a channel region which adjoins a first surface of the SiC substrate; a source region of the first conductivity type adjoining a first end of the channel region; an extension region of the first conductivity type at an opposite side of the body region as the source region and vertically extending to the drift region; a buried region of the second conductivity type below the body region and having a tail which extends toward the first surface and adjoins the extension region; and a compensation region of the first conductivity type protruding from the extension region into the body region along the first surface and terminating at a second end of the channel region opposite the first end.

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Erlangen, Germany

Michael Hell