Patent ID: 7560355

Claim:
A method of making a semiconductor wafer for a semiconductor junction diode device having a target forward voltage drop and a target reverse breakdown voltage, comprising: providing a semiconductor substrate of a first conductivity type, said substrate having a front surface and a back surface; a first doping step of doping the substrate through the back surface with a first dopant of the first conductivity type in an amount sufficient to form a semiconductor junction diode device having a target forward voltage drop, wherein a first diffusion layer formed by said first doping step has a dopant concentration with a first dopant profile that is either constant or decreasing with increasing depth through the back surface of the substrate; and a second doping step of doping the substrate through the front surface with a second dopant of the first conductivity type in an amount sufficient to form the semiconductor junction diode device such that it has a target reverse breakdown voltage, wherein a second diffusion layer formed by said second doping step has a dopant concentration with a second dopant profile that is either constant or decreasing with increasing depth through the front surface of the substrate.