CN-114582969-B - Diode structure of power semiconductor device

Abstract

The invention discloses a diode structure of a power semiconductor device. The power semiconductor device includes a semiconductor body coupled to a first load terminal and a second load terminal. The body includes at least one diode structure configured to conduct a load current between the terminals and including an anode port electrically connected to a first load terminal and a cathode port electrically connected to a second load terminal, and a drift region and a field stop region of the same conductivity type. The cathode port includes a first port portion and a second port portion having opposite conductivity types. The transition between each of the second port portions and the field stop region forms a respective pn-junction extending in the first lateral direction. The lateral separation distance between immediately adjacent ones of the second port portions is smaller in the second group than in the first group.

Inventors

• R. Balbersk
• P.C. Brandt
• J.G. Raven

Assignees

• 英飞凌科技股份有限公司

Dates

Publication Date

20260505

Application Date

20170920

Priority Date

20160920

Claims (13)

1. 1. A power semiconductor device, comprising: a semiconductor body coupled to a first load terminal and a second load terminal, wherein the semiconductor body comprises: A drift region having a dopant of a first conductivity type; At least one diode structure configured to conduct a load current between the first and second terminals and including an anode port electrically connected to the first load terminal and a cathode port electrically connected to the second load terminal; A field stop region having a dopant of the first conductivity type at a higher dopant concentration than the drift region, the field stop region being disposed between the cathode port and the drift region; an active region and a termination region laterally separating the active region from lateral edges of the semiconductor body, Wherein the cathode port comprises: A first port portion having a dopant of a first conductivity type and a second port portion having a dopant of a second conductivity type complementary to the first conductivity type, a transition between each of the second port portions and the field stop region forming a respective pn junction extending in a first lateral direction; Wherein a first set of first and second port portions is provided in the active region, the first set comprising first port portions alternating between the second port portions, Wherein a second set of first and second port portions is provided in the termination region, the second set including first port portions alternately arranged between the second port portions, and Wherein the lateral separation distance between immediately adjacent ones of the second port portions is smaller in the second group than in the first group.
2. 2. The power semiconductor device of claim 1, wherein the active region comprises one or more transistor structures, and wherein the termination region is devoid of transistor structures.
3. 3. The power semiconductor device of claim 2, wherein the first port portion is arranged in electrical contact with the second load terminal, and wherein the second port portion is isolated from the second load terminal by the first port portion.
4. 4. The power semiconductor device of claim 2, wherein a doping concentration of the second port portion is less than a doping concentration of each of the first port portions.
5. 5. A power semiconductor device, comprising: A semiconductor body, comprising: A drift region having a dopant of a first conductivity type; a field stop region having a dopant of the first conductivity type at a higher dopant concentration than the drift region, and An active region and a termination region laterally separating the active region from lateral edges of the semiconductor body, Wherein the termination region comprises: A first port portion having a dopant of a first conductivity type and a second port portion having a dopant of a second conductivity type complementary to the first conductivity type, the transition between each of the second port portions and the field stop region forming a respective pn-junction extending in a first lateral direction, wherein a diffusion voltage of a respective one of the pn-junctions in an extension direction perpendicular to the first lateral direction is greater than a lateral voltage drop laterally overlapping a lateral extension of the respective pn-junction.
6. 6. The power semiconductor device of claim 5, wherein said active region comprises one or more transistor structures, and wherein said termination region is devoid of transistor structures.
7. 7. The power semiconductor device of claim 5 wherein said semiconductor body comprises a cathode port coupled to a load electrode, and wherein said first port portion and said second port portion are disposed in said cathode port.
8. 8. The power semiconductor device of claim 5 wherein said lateral voltage drop is caused by a portion of a load current formed by charge carriers of said first conductivity type.
9. 9. The power semiconductor device of claim 5 wherein said lateral voltage drop occurs over a distance in a first lateral direction that is equal to 50% of the total extension of the respective second port portion in the first lateral direction.
10. 10. A power semiconductor device, comprising: a semiconductor body coupled to a first load terminal and a second load terminal, wherein the semiconductor body comprises: A drift region having a dopant of a first conductivity type; An anode port electrically connected to the first load terminal; A cathode port electrically connected to the second load terminal; A field stop region having a dopant of the first conductivity type at a higher dopant concentration than the drift region, the field stop region being disposed between the cathode port and the drift region, and A transition region laterally separating the transistor region from the diode region, Wherein the transistor region comprises one or more active transistor devices, Wherein the diode region comprises a diode structure, Wherein in the transition region and the diode region, the cathode port includes: A first port portion having a dopant of a first conductivity type and a second port portion having a dopant of a second conductivity type complementary to the first conductivity type, a transition between each of the second port portions and the field stop region forming a respective pn junction extending in a first lateral direction; Wherein a lateral separation distance between immediately adjacent ones of the second port portions is greater in the diode region than in the transition region.
11. 11. The power semiconductor device of claim 10 further comprising an active region comprising one or more transistor structures, and wherein the transition region and the diode region are devoid of transistor structures.
12. 12. The power semiconductor device of claim 10 wherein said transistor region comprises a vertical transistor comprising: A gate trench extending through the anode port and into the drift region, the gate trench including a conductive gate electrode and a gate dielectric insulating the gate electrode from the semiconductor body, and A source region adjacent to the gate trench and vertically separated from the drift region by a portion of the anode region, Wherein the gate electrode is configured to control a conduction channel between the source region and the drift region.
13. 13. The power semiconductor device of claim 12, wherein the vertical transistor is configured as an insulated gate bipolar transistor configured to conduct forward current between the first and second load terminals, and wherein the diode structure is configured to conduct reverse current between the first and second load terminals.

Description

Diode structure of power semiconductor device Technical Field The present specification relates to embodiments of power semiconductor devices having diode structures and to embodiments of processing power semiconductor devices having diode structures. Background Many functions of modern equipment in automotive, consumer and industrial applications, such as converting electrical energy and driving motors or machines, rely on power semiconductor devices. Such as Insulated Gate Bipolar Transistors (IGBTs), metal Oxide Semiconductor Field Effect Transistors (MOSFETs), and diodes, to name a few, have been used in a variety of applications including, but not limited to, switches in power supplies and power converters. A power semiconductor device generally includes a semiconductor body configured to conduct a load current along a load current path between two load terminals of the device. For example, the power semiconductor device is a diode or, correspondingly, comprises a diode structure in order to allow a flow of load current in the forward or reverse direction and to block a voltage in the other direction. In addition, the power semiconductor device may be a controlled device. For example, a turn-on function may be provided to allow the forward voltage to be blocked. Further, a turn-off function may be provided so as to suppress the flow of load current in the forward direction. For example, the load current path may be controlled by means of insulated electrodes, sometimes referred to as gate electrodes. For example, the control electrode may set the power semiconductor device in one of a conducting state (which is also referred to as "on state") and a blocking state when a corresponding control signal is received from, for example, the driver unit. Power semiconductor devices should generally exhibit low losses. If the power semiconductor device comprises a transistor function, i.e. provides switching capability, the total loss is substantially formed by the on-state loss and by the switching loss. In order to keep the on-loss low, the lifetime of the charge carriers contributing to the load current should be relatively long, whereas in order to keep the switching loss low, the lifetime should be relatively short. Disclosure of Invention According to an embodiment, a power semiconductor device includes a semiconductor body coupled to each of a first load terminal and a second load terminal. The semiconductor body includes a drift region having a dopant of a first conductivity type, at least one diode structure configured to conduct a load current between the terminals and including an anode port electrically connected to the first load terminal and a cathode port electrically connected to the second load terminal, a field stop region having a dopant of the first conductivity type at a higher dopant concentration than the drift region, wherein the field stop region is disposed between the cathode port and the drift region. The cathode port comprises a first port portion having a dopant of a first conductivity type and a second port portion having a dopant of a second conductivity type complementary to the first conductivity type, a transition between each of the second port portions and the field stop region forming a respective pn-junction extending in a first lateral direction, wherein a diffusion voltage of a respective one of the pn-junctions in an extension direction perpendicular to the first lateral direction is greater than a lateral voltage drop laterally overlapping a lateral extension of the respective pn-junction. According to further embodiments, a power semiconductor device includes a semiconductor body coupled to each of a first load terminal and a second load terminal. The semiconductor body includes a drift region having a dopant of a first conductivity type, at least one diode structure configured to conduct a load current between the terminals and including an anode port electrically connected to the first load terminal and a cathode port electrically connected to the second load terminal, a field stop region having a dopant of the first conductivity type at a higher dopant concentration than the drift region, wherein the field stop region is disposed between the cathode port and the drift region. The cathode port comprises a first port portion having a dopant of a first conductivity type and a second port portion having a dopant of a second conductivity type complementary to the first conductivity type, the transition between each of the second port portions and the field stop region forming a respective pn-junction, the pn-junction extending in a first lateral direction. The second load terminal exhibits a contact area facing the semiconductor body, and wherein, in the active region of the power semiconductor device, a percentage fraction of the contact area laterally overlapping the second port portion is at most one half of a percentage fraction of the contact area laterally overlapp