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US 12,464,747 B2Granted
Shielded trench devices
AssigneeIpower Semiconductor
InventorHamza Yilmaz
Life of this patent
Estimating the term…
Abstract
A shield trench power device such as a trench MOSFET or IGBT includes a substrate or an epitaxial layer of silicon, silicon carbide, gallium nitride, or gallium arsenide and employs an in-trench structure including a gate structure and an underlying polysilicon or oxide shield region that contacts a shield region in an epitaxial or crystalline layer of the device. The poly silicon region may be laterally confined by spacers in a gate trench and may contact or be isolated from the underlying shield region. Alternatively, the polysilicon region may be replaced with an insulating region.
Claims7
A trench device comprising:
- a semiconductor layer of a first conductivity type, the semiconductor layer containing one or more trenches in an active device area of the semiconductor layer and one or more shield regions of a second conductivity type respectively underlying the one or more trench;
- and
- for each of the trenches, the trench device further comprising:
- a shield polysilicon region of the second conductivity type in the trench and contacting the shield region underlying the trench, the shield polysilicon region being confined laterally by first dielectric spacers in the trench;
- a dielectric layer on the shield polysilicon region in the trench;
- a trench gate structure on the dielectric layer in the trench;
- wherein the semiconductor layer comprises at least one of silicon, silicon carbide, gallium nitride, and gallium arsenide;
- a substrate comprising at least one of silicon, silicon carbide, gallium nitride, and gallium arsenide, the substrate being either a semiconductor of the first conductivity type or a semiconductor of the second conductivity type, the semiconductor layer being on the substrate;
- and
- a bottom electrode on a bottom surface of the substrate.
7 more elements
Dependencies are inferred from the claim text.