Patent ID: 7629645

Claim:
An insulated-gate transistor including: a semiconductor layer of a first conductivity type, an insulated gate comprising a trench gate extending into the semiconductor layer, a source and a drain regions of a second conductivity type formed in the semiconductor layer at respective sides of the trench gate, wherein each one of the source and drain regions includes: a first doped region having a depth ranging from approximately 2.5 μm to approximately 3 μm, having a first dopant concentration ranging from approximately 1*10 15 ions/cm 3 to approximately 1*10 17 ions/cm 3 , formed in the semiconductor layer adjacent to the trench gate, said first dopant concentration being such that a breakdown voltage of the junction formed by the first doped region and the semiconductor layer is higher than a predetermined breakdown voltage, and a second doped region, having a second dopant concentration higher than the first dopant concentration ranging from approximately 1*10 17 ions/cm 3 to approximately 1*10 19 ions/cm 3 , said second doped region being formed in the first doped region and being spaced apart from the trench gate, the second dopant concentration being adapted to form a non-rectifying contact for electrically contacting the first doped region.