Patent ID: 8658492

Claim:
A method of manufacturing a semiconductor power device integrated with at least one ESD protection diode, comprising: forming an epitaxial layer of a first conductivity type; forming a plurality of trenched gates, and a plurality of body regions of a second conductivity type in said epitaxial layer; depositing an un-doped poly-silicon layer; carrying out ion implantation with dopant of said second conductivity type; applying a poly mask and etching said un-doped poly-silicon layer to leave necessary portion for formation of the ESD protection diode; applying a source mask; carrying out source dopant ion implantation for formation of source regions and cathode (or anode) regions in said ESD protection diode; forming a dopant out-diffusion suppression layer as a first contact interlayer after source dopant ion implantation, wherein said dopant out-diffusion suppression layer covering outer surface of said ESD protection diode comprising multiple back-to-back doped regions with said first conductivity type next to said second conductivity type; performing source dopant activation or diffusion; depositing a second contact interlayer on top of said first contact interlayer; applying a contact mask and forming a plurality of contact trenches starting from top of said second contact interlayer, wherein said contact trenches comprise at least two ESD contact trenches and a plurality of source-body contact trenches, each of said ESD contact trenches further extending into a cathode (or anode) region on each side of said ESD protection diodes, said source-body contact trenches further penetrating through said source regions and extending into said body regions; carrying out ion implantation with dopant of said second conductivity type to form a body contact doped region surrounding at least bottom of the source-body contact trench; forming a contact metal plug in each of said contact trenches; depositing a front metal on top of said second contact interlayer; applying a metal mask and patterning said front metal into a source metal and a gate metal.