METHOD FOR FORMING TRENCH MOSFET DEVICE WITH LOW PARASITIC RESISTANCE

摘要

Groove MOSFET device in a kind of top of source region epitaxial layer for being formed and shallowly injecting the first conductive type with deep dopant is provided. This method comprises: (one) forms the injecting mask of composition on epitaxial layer, wherein patterning implantation mask includes the insulation layer of composition and the region at least covering part source, and the hole at least partly epitaxial layer that wherein the patterning implantation mask has is between source region; (2) shallow dopant region is formed by following process, which includes: that (2) of the first energy level of the first dopant that (1) injects the second conduction type in the top of epitaxial layer diffuse through the hole and at high temperature by the first dopant from upper surface to the epitaxial layer of the first depth; (3) deep dopant region is formed by following process, which includes: that (2) of the second energy level of the second dopant that (1) injects the second conduction type in the top of epitaxial layer diffuse through the hole and at high temperature by the epitaxial layer of the upper surface of the second depth of the second dopant; The insulation layer of d enlarged openings compositions. In the method, the second energy level is greater than the first energy level, and the second depth is greater than the first depth, and the first and second dopants can be identical or different. It is, for example, possible to use methods of the invention to form a kind of device, including multiple trench MOSFET cells.