High Frequency Power Diode and Method for Manufacturing the Same

A high frequency power diode comprising:

• a semiconductor wafer having a first main side and a second main side opposite to the first main side,
• a first layer formed in the semiconductor wafer adjacent to the first main side, the first layer having a first conductivity type which is either n- or p-type conductivity,
• a second layer formed in the semiconductor wafer adjacent to the second main side, the second layer having a second conductivity type which is either n- or p-type conductivity but different from the first conductivity type,
• a third layer formed in the semiconductor wafer between the first layer and the second layer the third layer having the second conductivity type,
• wherein the first layer has a first conductivity type dopant concentration decreasing from 1019 cm−3 or more adjacent to the first main side of the wafer to 1.5·1015 cm−3 or less at an interface of the first layer with the third layer,
• wherein the second layer has a second conductivity type dopant concentration decreasing from 1019 cm−3 or more adjacent to the second main side of the wafer to 1.5·1015 cm−3 at an interface of the second layer with the third layer, and
• wherein the third layer has a second conductivity type dopant concentration of 1.5·1015 cm−3 or less
• characterized in that the first conductivity type dopant concentration in the first layer at a distance of 50 μm from the first main side and the second conductivity type dopant concentration in the second layer at a distance of 50 μm from the second main side is 1017 cm−3 or more, respectively, and the thickness of the third layer is less than 60 μm.