US 12,439,636 B2
Transistor device
Stefan Tegen, Dresden (DE); Alessandro Ferrara, Landskron (AT); Franz Hirler, Isen (DE); Andrei Josiek, Dresden (DE); and Matthias Kroenke, Dresden (DE)
Assigned to Infineon Technologies Austria AG, Villach (AT)
Filed by Infineon Technologies Austria AG, Villach (AT)
Filed on Jun. 23, 2022, as Appl. No. 17/847,998.
Claims priority of application No. 21183187 (EP), filed on Jul. 1, 2021.
Prior Publication US 2023/0006059 A1, Jan. 5, 2023
Int. Cl. H01L 29/06 (2006.01); H01L 29/40 (2006.01); H01L 29/78 (2006.01); H10D 30/66 (2025.01); H10D 62/10 (2025.01); H10D 64/00 (2025.01)
CPC H10D 30/668 (2025.01) [H10D 62/103 (2025.01); H10D 64/117 (2025.01)] 29 Claims
OG exemplary drawing
 
1. A transistor device, comprising:
a semiconductor substrate having a first major surface, a cell field, and an edge termination region laterally surrounding the cell field, wherein the cell field comprises:
a plurality of elongate trenches that extend from the first major surface into the semiconductor substrate and that are positioned substantially parallel to one another such that one or more inner elongate trenches are arranged between two outermost elongate trenches; and
elongate mesas, each elongate mesa being formed between neighbouring elongate trenches, wherein the elongate mesas comprise a drift region, a body region on the drift region and a source region on the body region,
wherein in a top view, one or both of the outermost elongate trenches has a different contour from the one or more inner elongate trenches,
wherein the edge termination region comprises an edge trench that extends from the first major surface into the semiconductor substrate and that laterally surrounds the cell field,
wherein the edge trench comprises longitudinal trench portions and transverse trench portions that extend between the longitudinal trench portions such that an inner trench corner is formed at each intersection between an inner side wall of the longitudinal trench portion and an inner side wall of the transverse trench portion,
wherein an edge mesa is formed between the edge trench and the cell field, and
wherein the inner trench corner of the edge trench has a radius of curvature that is greater than the width of the edge mesa measured between the longitudinal trench portion and a longitudinal side wall of the outermost elongate trench and/or the inner trench corner of the edge trench has a radius of curvature that is greater than the width of the elongate mesa.