Asymetrical Field-Effect Semiconductor Device with Sti Region
AssigneeNXP B.V.
InventorTheodore James Letavic
Life of this patent
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Abstract
A high voltage asymmetric semiconductor device (20) that includes a shallow trench isolation (STI) region (22) that forms a dielectric between a drain (34) and a gate (36) to allow for high voltage operation, wherein the STI region includes a lower corner (24) that is shaped, e.g. rounded, to reduce an impact ionization rate. Exemplarity the shaped corner terminates on a (111) crystalline plane facet.
Claims18
An asymmetric semiconductor device that includes a shallow trench isolation (STI) region that forms a dielectric between a drain and a gate to allow for high voltage operation, wherein the STI region includes a lower corner that is shaped to reduce an impact ionization rate.
A method of forming an asymmetric semiconductor device, comprising:
- forming a deep well implant of a first type;
- forming a first well implant of the first type above the deep well implant and below a drain location and part of a gate location;
- and
- forming a shallow trench isolation (STI) region in the first well implant below a portion of the gate location adjacent the drain location, wherein the STI region includes a lower corner that is shaped to reduce an impact ionization rate.
The method of any preceding claim, comprising the further step of shaping a second lower corner of the STI region.
An asymmetric semiconductor device that includes a shallow trench isolation (STI) region that forms a dielectric between two active regions, wherein the STI region includes a lower corner that is shaped to improve device performance.
Dependencies are inferred from the claim text.