Power transistor device having ultra deep increased concentration
First Claim
1. A power transistor device having bipolar device forward current carrying characteristics and MOS gate control characteristics;
- said device comprising a thin chip of semiconductor material having a substrate of one conductivity type, a lightly doped layer of semiconductor material of the opposite conductivity type disposed atop one surface of said substrate, a plurality of spaced base regions of said one conductivity type extending into the opposite surface of said layer of semiconductor material to a given depth, a plurality of source regions of said opposite conductivity type formed in respective ones of said plurality of spaced base regions and defining respective surface channel regions, a gate insulation layer disposed over said channel regions, a conductive gate layer disposed over said gate insulation layer, a first main electrode connected to said plurality of source regions and a second main electrode connected to said substrate, the regions between said spaced base regions having an increased concentration of carriers of said opposite conductivity type which extends from said opposite surface to a depth greater than the depth of said base regions;
said increased concentration being greater than that of the remaining portion of said layer of semiconductor material over its full depth.
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Accused Products
Abstract
A cellular insulated gate bipolar transistor ("IGBT") device employs increased concentration in the active region between spaced bases to a depth greater than the depth of the base regions. The implant dose which is the source of the increased concentration is about 3.5×1012 atoms per centimeter squared and is driven for about 10 hours at 1175° C. Lifetime is reduced by an increased radiation dose to reduce switching loss without reducing breakdown voltage or increasing forward voltage drop above previous levels. The increased concentration region permits a reduction in the spacing between bases and provides a region of low localized bipolar gain, increasing the device latch current. The avalanche energy which the device can successfully absorb while turning off an inductive load is significantly increased. The very deep increased conduction region is formed before the body and source regions in a novel process for making the new junction pattern.
65 Citations
31 Claims
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1. A power transistor device having bipolar device forward current carrying characteristics and MOS gate control characteristics;
- said device comprising a thin chip of semiconductor material having a substrate of one conductivity type, a lightly doped layer of semiconductor material of the opposite conductivity type disposed atop one surface of said substrate, a plurality of spaced base regions of said one conductivity type extending into the opposite surface of said layer of semiconductor material to a given depth, a plurality of source regions of said opposite conductivity type formed in respective ones of said plurality of spaced base regions and defining respective surface channel regions, a gate insulation layer disposed over said channel regions, a conductive gate layer disposed over said gate insulation layer, a first main electrode connected to said plurality of source regions and a second main electrode connected to said substrate, the regions between said spaced base regions having an increased concentration of carriers of said opposite conductivity type which extends from said opposite surface to a depth greater than the depth of said base regions;
said increased concentration being greater than that of the remaining portion of said layer of semiconductor material over its full depth. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 27, 28)
- said device comprising a thin chip of semiconductor material having a substrate of one conductivity type, a lightly doped layer of semiconductor material of the opposite conductivity type disposed atop one surface of said substrate, a plurality of spaced base regions of said one conductivity type extending into the opposite surface of said layer of semiconductor material to a given depth, a plurality of source regions of said opposite conductivity type formed in respective ones of said plurality of spaced base regions and defining respective surface channel regions, a gate insulation layer disposed over said channel regions, a conductive gate layer disposed over said gate insulation layer, a first main electrode connected to said plurality of source regions and a second main electrode connected to said substrate, the regions between said spaced base regions having an increased concentration of carriers of said opposite conductivity type which extends from said opposite surface to a depth greater than the depth of said base regions;
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18. A power transistor device;
- said device comprising a thin chip of semiconductor material having a substrate and a lightly doped layer of semiconductor material of one conductivity type disposed atop one surface of said substrate, a plurality of spaced base regions of the opposite conductivity type extending into the opposite surface of said layer of semiconductor material to a given depth, a plurality of source regions of said one conductivity type formed in respective ones of said plurality of spaced base regions and defining respective surface channel regions, a gate insulation layer disposed over said channel regions, a conductive gate layer disposed over said gate insulation layer, a source electrode connected to said plurality of source regions and a drain electrode connected to said substrate;
said spaced base regions being so closely spaced as to define a highly efficient parasitic JFET when using a doping concentration between said spaced base regions of the value of the concentration of said layer of semiconductor material;
the regions between said spaced base regions having an increased concentration of carriers of said one conductivity type which extends from said surface of said layer to a depth greater than the depth of said base regions and having a conductivity greater than that of the remaining portion of said layer. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26)
- said device comprising a thin chip of semiconductor material having a substrate and a lightly doped layer of semiconductor material of one conductivity type disposed atop one surface of said substrate, a plurality of spaced base regions of the opposite conductivity type extending into the opposite surface of said layer of semiconductor material to a given depth, a plurality of source regions of said one conductivity type formed in respective ones of said plurality of spaced base regions and defining respective surface channel regions, a gate insulation layer disposed over said channel regions, a conductive gate layer disposed over said gate insulation layer, a source electrode connected to said plurality of source regions and a drain electrode connected to said substrate;
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29. A power transistor device comprising a substrate of one conductivity type, a lightly doped layer of semiconductor material of the opposite conductivity type disposed atop one surface of said substrate, a plurality of spaced base regions of said one conductivity type extending into the opposite surface of said layer of semiconductor material to a given depth, a plurality of source regions of said opposite conductivity type formed in respective ones of said plurality of spaced base regions and defining respective surface channel regions therebetween, a gate insulation layer disposed over said channel regions, a conductive gate layer disposed over said gate insulation layer, a first main electrode connected to said plurality of source regions and a second main electrode connected to said substrate, the regions between said spaced base regions having an increased concentration of carriers of said opposite conductivity type which extends from said opposite surface to a depth greater than the depth of said base regions;
- said increased concentration being greater than that of the remaining portion of said layer of semiconductor material over its full depth.
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30. A power transistor device having bipolar device forward current carrying characteristics and MOS gate control characteristics;
- said device comprising a substrate of a first conductivity type, a lightly doped layer of semiconductor material of a second opposite conductivity type disposed atop one surface of said substrate, a plurality of spaced base regions of said first conductivity type extending into the opposite surface of said layer of semiconductor material to a given depth, a plurality of source regions of said second conductivity type formed in respective ones of said plurality of spaced base regions defining respective surface channel regions, a gate insulation layer disposed over said channel regions, a conductive gate layer disposed over said gate insulation layer, a first main electrode connected to said plurality of source regions and a second main electrode in electrical connection with said layer of semiconductor material of the second conductivity type through a region of said first conductivity type, the regions between said spaced base regions having an increased concentration of carriers of said second conductivity type which extends from said opposite surface to a depth greater than the depth of said base regions;
said increased concentration being greater than that of the remaining portion of said of semiconductor material over its full depth. - View Dependent Claims (31)
- said device comprising a substrate of a first conductivity type, a lightly doped layer of semiconductor material of a second opposite conductivity type disposed atop one surface of said substrate, a plurality of spaced base regions of said first conductivity type extending into the opposite surface of said layer of semiconductor material to a given depth, a plurality of source regions of said second conductivity type formed in respective ones of said plurality of spaced base regions defining respective surface channel regions, a gate insulation layer disposed over said channel regions, a conductive gate layer disposed over said gate insulation layer, a first main electrode connected to said plurality of source regions and a second main electrode in electrical connection with said layer of semiconductor material of the second conductivity type through a region of said first conductivity type, the regions between said spaced base regions having an increased concentration of carriers of said second conductivity type which extends from said opposite surface to a depth greater than the depth of said base regions;
Specification