Shield gate MOSFET and method for fabricating the same

• Main Authors: HO, CHANGIN, JIANG, YONG-KANG, SU, HUNG-I
• Format: Patent
• Language: Chinese; English
• Published: 01.02.2021
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

A shield gate MOSFET includes an epitaxial layer having a first conductivity type, a plurality of trenches in the epitaxial layer, a shield gate disposed in the trench, a control gate on the shield gate in the trench, an insulating layer between the shield gate and the epitaxial layer, a gate oxide layer between the control gate and the epitaxial layer, an inter-gate oxide layer between the shield gate and the control gate, and a first doped region in the epitaxial layer at the bottom of the trench, and a second doped region between the bottom of the trench and the first doped region. The first doped region has a second conductivity type, and the second doped region has the first conductivity type, and thus the leakage path can be reduced in the presence of the second doped region so as to improve a breakdown voltage.