Patent ID: 8546882

Claim:
A terminal structure for superjunction device, the superjunction device comprising a first type substrate and a first type epitaxial layer formed on the first type substrate, a central part of the superjunction device being an active area, a plurality of trench stripes being formed in the first type epitaxial layer in the active area, a second type impurity being filled into the trench stripes to form second type trench stripes, the superjunction device further comprising a plurality of second type wells, formed beneath a surface of the first type epitaxial layer, each second type well surrounding a second type trench stripe; source regions, formed in each of the second type wells; a gate oxide layer, a gate electrode and a source electrode, respectively formed above the first type epitaxial layer; and a drain electrode, formed at a backside of the first type substrate; wherein from a top view, the terminal structure is arranged around the periphery of the active area, and the terminal structure comprises from inside out at least one second type implantation ring, a plurality of trench rings and a channel cut-off ring; from a cross section view, the second type implantation ring is formed beneath the surface of the first type epitaxial layer and covers at least one trench ring, each of the trench rings being formed in the first type epitaxial layer and being filled with a second type impurity, the channel cut-off ring being formed beneath the surface of the first type epitaxial layer near a border of the superjunction device; the terminal structure further comprises an inter layer dielectric film, formed above the first type epitaxial layer, covering a part of the second type implantation ring and the plurality of trench rings; and a plurality of field plates, including: an inside field plate, formed on the inter layer dielectric film; and at least one outside field plate, formed on or inside the inter layer dielectric film; the plurality of field plates being isolated from one another; wherein, the first type is N type when the second type is P type; the first type is P type when the second type is N type.