Schottky rectifier with surge-current ruggedness

A semiconductor device, comprising:

• a Silicon Carbide (SiC) layer;
• a channel region of a first conductivity type formed on the SiC layer;
• a multi-layer body of a second conductivity type formed within the channel region and extending in a direction of the SiC layer, the multi-layer body including a first layer having a first doping concentration, a second layer adjacent to the first layer and having a second doping concentration less than the first doping concentration, and a third layer adjacent to the second layer and having a third doping concentration less than the second doping concentration;
• and
• a charge-balanced region that includes the third layer and a portion of the channel region adjacent to the third layer, wherein, within the charge-balanced region, charges of non-compensated acceptors and donors in the third layer and the portion of the channel region have a deviation of approximately 1×1013 cm−2 or lower.

A method of making a semiconductor device, the method comprising:

• forming a Silicon Carbide (SiC) substrate;
• forming an epitaxial layer of a first conductivity type on the SiC substrate;
• forming a portion of a charge-balancing body having donors of a second conductivity type;
• repeating the forming of the epitaxial layer and the forming the portion of the charge-balancing body until the charge-balancing body reaches a specified thickness;
• forming an injection layer on the charge-balancing body, the injection layer having a doping concentration of the second conductivity type that is higher than a doping concentration of the charge-balancing body;
• and
• forming a contact layer on the injection layer,
• wherein, within a charge-balanced region that includes the charge-balancing body and a surrounding portion of the epitaxial layer, charges of non-compensated acceptors and donors in the charge-balancing body and the surrounding portion of the epitaxial layer have a deviation of approximately 1×1013 cm−2 or lower.

A semiconductor device, comprising:

• a Silicon Carbide (SiC) layer;
• a channel region of a first conductivity type formed on the SiC layer;
• a multi-layer body of a second conductivity type formed within the channel region and extending in a direction of the SiC layer, the multi-layer body including a tunnel contact layer, an injection layer adjacent to the tunnel contact layer, and a deep layer adjacent to the injection layer;
• and
• a charge-balanced region that includes the deep layer and a portion of the channel region adjacent to the deep layer, within which charges of non-compensated acceptors and donors in the deep layer and the portion of the channel region have a deviation of approximately 1×1013 cm−2 or lower,
• wherein the multi-layer body extends at least thirty percent of a distance from the tunnel contact layer to the SiC layer.