Trench-gate semiconductor devices

摘要

A trench-gate vertical power transistor in which the trench-gates ( 11 ) are parallel stripes which extend across the active area ( 100 ). Source regions ( 13 ) and ruggedness regions ( 15 ) extend to a source contact surface as alternating stripe areas having a width perpendicular to and fully between each two adjacent parallel stripe trench-gates ( 11 ). The ruggedness regions ( 15 ) are more heavily doped than the source regions and this enables an increased length of the source regions with a consequent reduction in specific resistance of the transistor. For example, the mesa width ( 13,15 ) and the trench-gate ( 11 ) width may both be about 0.4 mum, the ruggedness region ( 15 ) length may be about 1 mum and the source region ( 13 ) length may be about 20 mum. The doping concentration of the p type ruggedness regions ( 15 ) may be approximately 10 times greater than the doping concentration of the n type regions ( 13 ), for example about 10₂₁ cm_-3 and about 10₂₀ cm_-3 respectively.