| CPC H01L 29/7811 (2013.01) [H01L 29/0638 (2013.01); H01L 29/1095 (2013.01); H01L 29/407 (2013.01); H01L 29/7813 (2013.01)] | 20 Claims |
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1. A shielded gate trench (SGT) device comprising:
an active area, a termination area, a gate metal pad area and at least one gate metal runner;
said active area comprising a plurality of gate trenches formed in an epitaxial layer of a first conductivity type onto a substrate of said first conductivity type along a first axis including a first type active trenches having a first active trench length, and a second type active trenches near the gate pad area having a second active trench length, wherein said first active trench length is longer than the second active trench length;
said termination area comprising at least one first type termination trench surrounding outer periphery of said plurality of gate trenches in a first direction along said first axis and in a second direction along a second axis wherein said first axis is vertical to said second axis, and said at least one first type termination trench is separated from said plurality of gate trenches and does not surround said gate metal pad area;
an inner edge of a first termination trench of said termination trenches along said second axis adjacent to trench ends of said plurality of gate trenches has a plurality of wave shape portions in regions between two adjacent trench ends of said plurality of gate trenches while outer edges have a straight shape, and inner and outer edges of other said termination trenches have a straight shape;
said first type active trench near said gate metal pad area has at least one wave shape portion in a region between a trench end of said second type active trench adjacent to said first type active trench and said first termination trench near one corner of said gate metal pad area;
said SGT device further comprising:
said gate trenches are formed in said active area, surrounded by a first type source regions of a first conductivity type are encompassed in a first type body regions of a second conductivity type near a top surface of said epitaxial layer of said first conductivity type, each of said gate trenches is filled with a gate electrode and a shielded gate electrode; said shielded gate electrode is insulated from said epitaxial layer by a first insulating film, said gate electrode is insulated from said epitaxial layer by a gate oxide, said shielded gate electrode and said gate electrode are insulated from each other by an (Inter-Poly Oxide) IPO film, said gate oxide surrounds said gate electrode and has less thickness than said first insulating film;
a termination trench field plate is disposed in each of said termination trenches in said termination area and insulated from said epitaxial layer by a second insulating film, wherein each of said termination trenches has a trench width and a trench depth greater than or equal to said each of said gate trenches in said active area;
said termination trench field plate is shorted together with said first type source and said first type body regions through a source metal;
said gate electrode inside each of said gate trenches is connected to said gate metal pad through said at least one gate metal runner having a plurality of gate trench contacts underneath; and
said shielded gate electrode inside each of said plurality of gate trenches is connected to a source metal through at least one shielded gate trench contact.
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