Patent ID: 7439145

Claim:
A semiconductor fabrication method, comprising: providing a semiconductor diode structure, wherein the semiconductor diode structure comprises: (a) a substrate layer comprising a semiconductor material and first dopants of a first doping polarity, (b) a first layer having an opening, the first layer being on top of and in direct physical contact with the substrate layer, the first layer consisting of only one piece of continuously distributed semiconductor material and second dopants of a second doping polarity, the second doping polarity being opposite to the first doping polarity, and (c) a second layer being on top of and in direct physical contact with the first layer, the second layer comprising the semiconductor material and third dopants of the second doping polarity, the first layer having a higher doping concentration than the second layer, wherein the second layer is in direct physical contact with the substrate layer through the opening of the first layer; forming an electrode structure being on top of and in direct physical contact with the second layer, the electrode structure including at least an anode and a cathode, wherein both the anode and the cathode are (i) in direct physical contact with the second layer and (ii) not in direct physical contact with the first layer, wherein said providing the semiconductor diode structure comprises: providing a semiconductor layer; after said providing the semiconductor layer is performed, implanting the second dopants in the semiconductor layer resulting in the first layer with the opening; and after said implanting the second dopants is performed, implanting the third dopants in the semiconductor layer resulting in the second layer, and wherein said providing the semiconductor diode structure further comprises: choosing a desired breakdown voltage for the semiconductor diode structure; determining a size of the opening so as to achieve the desired breakdown voltage; and forming the first layer having the opening with the determined size; and after said providing the semiconductor diode structure is performed, changing size and shape of the first layer resulting the opening disappearing.