Termination structure of super-junction power device comprising plurality of runway-shaped rings as the resistive field plate

Patent metadata

Field	Value
Publication number	US-12464766-B2
Application number	US-202217876572-A
Country	US
Kind code	B2
Filing date	Jul 29, 2022
Priority date	Apr 28, 2022
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

A termination structure of a super-junction power device has a novel polysilicon resistive field plate at the top of a termination region between a transition region and an edge of the device. By utilizing the regular distribution of potential in the field plate, an additional electric field is introduced at the top of the termination structure to limit the expansion of a non-depletion region and optimize the distribution of charges. The termination structure includes a first doping type epitaxial layer, a second doping type compensation region, a second doping type body region, a second doping type lateral connection layer, a second doping type body contact region, a first doping type source contact region, a gate oxide layer, a passivation layer, a field oxide layer, a gate electrode, a second doping type edge contact region, a polysilicon resistive field plate, a metal layer and the like.

First claim

What is claimed is:

1 . A termination structure of a super-junction power device, wherein a polysilicon resistive field plate is arranged above a silicon layer; the polysilicon resistive field plate comprises a plurality of runway-shaped rings surrounding a gate metal layer; each of the plurality of runway-shaped rings is formed by connecting long straights in a middle of an upper side and a lower side, short straights in a middle of a left side and a right side, and curves between the long straights and the short straights; the plurality of runway-shaped rings have a first end directly connected to the gate metal layer and a second end directly connected to an edge metal layer; the first end and the second end are located on the long straights or the curves; and the plurality of runway-shaped rings are directly connected to each other.

2 . The termination structure of the super-junction power device according to claim 1 , wherein the plurality of runway-shaped rings have equal width and are arranged at equal spacing; alternatively, the plurality of runway-shaped rings have equal width and are arranged at variable spacings; alternatively, the plurality of runway-shaped rings have variable widths and are arranged at variable spacings.

3 . The termination structure of the super-junction power device according to claim 1 , wherein the plurality of runway-shaped rings are connected at intervals through connection segments perpendicular to the long straights on a straight line formed by the first end and the second end; alternatively, the plurality of runway-shaped rings are connected at intervals through connection segments perpendicular to tangent lines of the curves on a line segment formed by the first end and the second end and a line segment formed by diagonal positions of the first end and the second end.

4 . The termination structure of the super-junction power device according to claim 1 , wherein each of the plurality of runway-shaped rings is not closed on the upper or lower long straights or upper and lower long straights, adjacent runway-shaped rings are connected through connection segments perpendicular to the long straights at a position where the plurality of runway-shaped rings are not closed, and the connection segments are offset from the long straights to the curves at equal spacing from inside to outside.

5 . The termination structure of the super-junction power device according to claim 1 , wherein the plurality of runway-shaped rings are partitioned by a divider line located on a central axis of the long straights; left and right sides of the plurality of runway-shaped rings are symmetrical about the divider line, and the plurality of runway-shaped rings are connected at intervals through connection segments perpendicular to the long straights on both sides of the divider line.

6 . The termination structure of the super-junction power device according to claim 3 , wherein the connection segment is made of polysilicon or metal.

7 . The termination structure of the super-junction power device according to claim 1 , wherein the first end is connected to the source metal layer instead of the gate metal layer.

8 . The termination structure of the super-junction power device according to claim 1 , wherein a number of the plurality of runway-shaped rings is greater than or equal to 6.

9 . The termination structure of the super-junction power device according to claim 1 , wherein the plurality of runway-shaped rings are replaced with an equal-width spiral line coiling around the gate metal layer, and a number of turns of the equal-width spiral line is greater than or equal to 6.

10 . The termination structure of the super-junction power device according to claim 1 , wherein the super-junction power device is a metal-oxide-semiconductor field effect transistor (MOSFET), an insulated gate bipolar-translater transistor (IGBT) or other power super-junction power devices adapted to super-junction structures.

11 . The termination structure of the super-junction power device according to claim 1 , wherein an active region A, a transition region B and a termination region C are arranged sequentially from an inside of the super-junction power device to an edge of the super-junction power device; the active region A, the transition region B and the termination region C share a first doping type substrate and a first doping type epitaxial layer; wherein
in the active region A, a plurality of second doping type compensation regions are located in and separated by the first doping type epitaxial layer; a second doping type body region is located on an upper surface of each of the plurality of second doping type compensation regions; a second doping type body contact region and a first doping type source contact region are located at a top of the second doping type body region; a gate oxide layer is located on upper surfaces of part of the first doping type epitaxial layer, part of the second doping type body region and part of the first doping type source contact region; a first gate electrode overlays an upper surface of the gate oxide layer; a passivation layer overlays upper surfaces of the first gate electrode and the first doping type source contact region; a source metal layer overlays upper surfaces of the second doping type body contact region, the first doping type source contact region and the passivation layer; in the transition region B, a plurality of second doping type compensation regions are located in and separated by the first doping type epitaxial layer; a second doping type body region is located adjacent to the active region and on upper surfaces of the plurality of second doping type compensation regions; a second doping type body contact region is located at a top of the second doping type body region; a second doping type lateral connection layer is located adjacent to the termination region and between the upper surfaces of the plurality of second doping type compensation regions and a bottom surface of the second doping type body region; a gate oxide layer is located on an upper surface of part of the second doping type body region; a field oxide layer is located on upper surfaces of part of the second doping type boy region and the first doping type epitaxial layer; a second gate electrode overlays the gate oxide layer and the field oxide layer; a passivation layer overlays the second gate electrode; a source metal layer overlays an upper surface of the second doping type body contact region; a gate metal layer is located at a top of the passivation layer and the second gate electrode, and the gate metal is in contact with the second gate electrode; and in the termination region C, a plurality of second doping type compensation regions are located in and separated by the first doping type epitaxial layer; a second doping type lateral connection layer is located adjacent to the transition region and on upper surfaces of the plurality of second doping type compensation regions; a field oxide layer overlays an upper surface of the first doping type epitaxial layer; a polysilicon resistive field plate is located above the field oxide layer; a passivation layer overlays the upper surfaces of the field oxide layer and the polysilicon resistive field plate; a second doping type edge contact region is located adjacent to the edge of the super-junction power device and at a top of the first doping type epitaxial layer; an edge metal layer is located adjacent to the edge of the super-junction power device, at the top of the passivation layer, and in contact with the second doping type edge contact region.

12 . The termination structure of the super-junction power

Assignees

• Univ Electronic Sci & Tech China
• Inst Of Electronic And Information Engineering Of Uestc In Guangdong

Inventors

• Qiao Ming
• Wang Ruidi
• Wang Yibing
• Zhang Bo

Classifications

• H10D64/115

  Resistive field plates, e.g. semi-insulating field plates · CPC title

• H10D62/111

  Multiple RESURF structures, e.g. double RESURF or 3D-RESURF structures · CPC title

• H10D12/441

  Vertical IGBTs · CPC title

• H10D62/106

  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 · CPC title

• H10D30/665 Primary

  having edge termination structures · CPC title