Semiconductor device and method for fabricating the same

A method for fabricating a semiconductor device, comprising:

• providing a semiconductor substrate, having a first conductivity type;
• forming a semiconductor layer over the semiconductor substrate, having the first conductivity type;
• forming a gate structure over a portion of the semiconductor layer;
• forming a first doped region in a portion of the semiconductor layer adjacent to a first side of the gate structure, having the first conductivity type;
• forming a second doped region in a portion of the semiconductor layer adjacent to a second side of the gate structure opposite to the first side, having a second conductivity type opposite to the first conductivity type;
• forming a third doped region in a portion of the first doped region, having the second conductivity type;
• forming a fourth doped region in a portion of the second doped region, having the second conductivity type opposite to the first conductivity type;
• forming a plurality of fifth doped regions in a plurality portions of the second doped region, having the first conductivity type, wherein the fifth doped regions are formed between the fourth doped region and the gate structure and the fifth doped regions physically contact the fourth doped region;
• forming an insulating layer over the second doped region, the gate structure, and a portion of the third doped region;
• forming a trench in a portion of the third doped region and the first doped region, exposing a portion of the semiconductor layer under the first doped region;
• performing an ion implantation process, implanting dopants of the first conductive type in the semiconductor layer exposed by the trench, thereby forming a sixth doped region, wherein the sixth doping region physically contacts with the semiconductor substrate;
• and
• forming a conductive contact in the trench, wherein the conductive contact physically contacts with the sixth doped region and does not extend into the sixth doped region.