A trench type silicon carbide MOSFET device structure and a method for manufacturing the same
By employing tilted injection to form a trench protection structure in silicon carbide MOSFET devices, the problem of excessively high gate oxide field strength is solved, thereby improving the reliability and conduction performance of the devices, while simplifying the fabrication process and reducing costs.
CN115394853BActive Publication Date: 2026-05-29SHENZHEN BASIC SEMICON LTD
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHENZHEN BASIC SEMICON LTD
- Filing Date
- 2022-08-05
- Publication Date
- 2026-05-29
AI Technical Summary
Technical Problem
Existing silicon carbide trench MOSFET devices have excessively high gate oxide field strength in the blocking state, leading to reliability issues. Furthermore, existing protection structures are complex, costly, or difficult to manufacture.
Method used
An inclined implantation method is used to form a trench protection structure. Combined with a simple fabrication process, including ion implantation and etching, it forms effective gate oxide protection while reducing the impact on on-resistance.
Benefits of technology
This achieves effective protection of the gate oxide in the blocking state, reduces the resistance of the current transport region, improves the body diode performance of the device, and reduces the complexity and cost of the fabrication process.
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Smart Images
Figure CN115394853B_ABST
Abstract
The application discloses a trench type silicon carbide MOSFET device, which comprises an n-type silicon carbide substrate, an n-type silicon carbide epitaxial layer located above the substrate, a trench gate located at the top of the epitaxial layer, an oxide layer wrapped at the lower part of the trench gate, and n-type source regions, p-type base regions and p-type trench protection regions located at both sides of the oxide layer and sequentially arranged from top to bottom; a current transmission region formed at the bottom of the oxide layer; a contact metal formed above the n-type source regions and the p-type base regions; an interlayer dielectric layer at the top of the trench gate; a metal pad and a passivation layer sequentially arranged above the interlayer dielectric layer; and a drain metal formed at the bottom of the device. The application further discloses a preparation method of the device. The method adopts an inclination injection to form a trench protection region structure, which effectively protects the gate oxide at the bottom of the trench and maximally reduces the influence of the trench protection region on the on-resistance, and has a lower current transmission region resistance.
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