US 12,446,243 B2
Semiconductor cell structure, IGBT cell structure, semiconductor structure, and method for manufacturing IGBT cell structure
Baowei Huang, Shenzhen (CN); and Haiping Wu, Shenzhen (CN)
Assigned to BYD SEMICONDUCTOR COMPANY LIMITED, Shenzhen (CN)
Filed by BYD SEMICONDUCTOR COMPANY LIMITED, Shenzhen (CN)
Filed on Mar. 22, 2023, as Appl. No. 18/187,852.
Application 18/187,852 is a continuation of application No. PCT/CN2021/120182, filed on Sep. 24, 2021.
Claims priority of application No. 202011017235.3 (CN), filed on Sep. 24, 2020.
Prior Publication US 2023/0246096 A1, Aug. 3, 2023
Int. Cl. H10D 12/00 (2025.01); H10D 12/01 (2025.01); H10D 62/10 (2025.01)
CPC H10D 12/481 (2025.01) [H10D 12/038 (2025.01); H10D 62/127 (2025.01)] 13 Claims
OG exemplary drawing
 
1. An insulated gate bipolar transistor (IGBT) cell structure, comprising:
an N-type drift layer, an N-type termination layer, a P-type collector layer, and a collector metal layer stacked in sequence, wherein:
on a side of the N-type drift layer facing away from the P-type collector layer and in the N-type drift layer, the IGBT cell structure comprises: two first trenches spaced apart from each other, a trench-shaped insulating oxide layer formed on an inner wall of each of the first trenches, a polysilicon electrode located in the trench-shaped insulating oxide layer, second trenches, each formed on the inner wall of the first trench, a trench-shaped gate oxide layer located in the second trench, a polysilicon gate located in the trench-shaped gate oxide layer, a P well region located between the first trenches, and two floating P regions spaced apart from each other;
the trench-shaped insulating oxide layer and the polysilicon gate in the first trench are both adjacently connected with the second trench in the first trench; the trench-shaped gate oxide layer is isolated from the trench-shaped insulating oxide layer through the polysilicon electrode; a depth of each of the floating P regions does not exceed a depth of the first trench; the floating P region is isolated from the P well region through the trench-shaped insulating oxide layer; and the gate oxide layers in the two second trenches are adjacently connected with the P well region.