Patent ID: 7169634

Claim:
A fabrication process for making an enhanced avalanche ruggedness Fast Recovery Diode, the process comprising: selecting a semiconductor material of a first dopant type; patterning and introducing a first dopant of a second type opposite in polarity to the first dopant type into the top surface of the semiconductor material at a peripheral region of the device; diffusing said first dopant to create field spreading structures for blocking reverse voltage; introducing a second dopant of the first type into a central portion of the semiconductor material top surface; diffusing said second dopant to create a region with enhanced doping concentration of the first type within the semiconductor material in the central portion of the device; introducing and diffusing a third dopant of the second type to a predetermined depth within said enhanced doping region to form a main PN junction and effect a lower avalanche breakdown in the central portion in relationship to a periphery of the main PN junction; and forming metal electrodes on the top surface and a backside of the semiconductor material to conduct current through the diode; further comprising a blanket implant of the first dopant type into the semiconductor surface to counter the effect of counter-doping and compensation by a life-time control dopant.