Semiconductor device with enhanced avalanche ruggedness

A method of operating a semiconductor device, comprising:

• receiving the semiconductor device, the semiconductor device comprising:
• a well region in a substrate;
• a doped region in the substrate over the well region;
• a plurality of gate electrodes disposed over the doped region and electrically coupled to each other;
• a plurality of source regions in the substrate and electrically coupled together;
• a plurality of drain regions in the substrate and electrically coupled together, wherein the plurality of gate electrodes, the plurality of source regions and the plurality of drain regions form a plurality of transistors, respectively;
• and
• a bulk region disposed in the doped region at a periphery of the doped region,
• wherein a first distance measured between a first transistor of the plurality of transistors and the bulk region is greater than a second distance measured between a second transistor of the plurality of transistors and the bulk region;
• measuring a first leakage current of the semiconductor device;
• applying a first voltage to the plurality of drain regions to cause a first avalanche current to occur in a first parasitic bipolar junction transistor corresponding to the first transistor earlier than a second parasitic bipolar junction transistor corresponding to the second transistor;
• and
• stopping application of the first voltage to the plurality of drain regions and measuring a second leakage current of the semiconductor device, wherein the second leakage current is substantially equal to the first leakage current.

A semiconductor device, comprising:

• a well region in a substrate;
• a doped region in the substrate over the well region;
• a plurality of gate electrodes disposed over the doped region and electrically coupled to each other;
• a plurality of source regions in the substrate and electrically coupled together;
• a plurality of drain regions in the substrate and electrically coupled together, wherein the plurality of gate electrodes, the plurality of source regions and the plurality of drain regions form a plurality of transistors, respectively;
• and
• a bulk region disposed in the doped region at a periphery of the doped region,
• wherein a first distance measured between a first transistor of the plurality of transistors and the bulk region is greater than a second distance measured between a second transistor of the plurality of transistors and the bulk region,
• wherein when the semiconductor device is configured to receive a first voltage at the plurality of drain regions to generate an avalanche current, a first avalanche current generated around the first transistor and shunted through the first transistor is generated earlier than a second avalanche current generated around the second transistor and shunted through the second transistor.