US 12,336,220 B2
Extended-drain metal-oxide-semiconductor devices with a gap between the drain and body wells
Bong Woong Mun, Singapore (SG); Upinder Singh, Singapore (SG); Jeoung Mo Koo, Singapore (SG); and Huihua Jiang, Singapore (SG)
Assigned to GlobalFoundries Singapore Pte. Ltd., Singapore (SG)
Filed by GlobalFoundries Singapore Pte. Ltd., Singapore (SG)
Filed on Feb. 24, 2022, as Appl. No. 17/679,177.
Prior Publication US 2023/0268436 A1, Aug. 24, 2023
Int. Cl. H10D 30/65 (2025.01); H10D 30/01 (2025.01)
CPC H10D 30/65 (2025.01) [H10D 30/0281 (2025.01)] 10 Claims
OG exemplary drawing
 
1. A structure for an extended-drain metal-oxide-semiconductor device, the structure comprising:
a semiconductor substrate including a buried isolation well and a high-voltage well;
a first body well in the high-voltage well;
a first source region in the first body well;
a drain well in the high-voltage well, the drain well including a first edge adjacent to the first body well, and the first edge of the drain well having a first spaced relationship with the first body well;
a drain region in the drain well; and
a first gate electrode laterally positioned between the first source region and the drain region,
wherein the first edge of the drain well and the first body well are separated by a first gap that is filled by a first portion of the high-voltage well, the first gap includes a first plurality of notches positioned along the first edge of the drain well, the first gap has a width dimension that varies with position along the first edge, and the first gap is fully overlapped by the first gate electrode.