| 摘要 |
PROBLEM TO BE SOLVED: To obtain a high speed diode which can soft recover from a maximum reverse rotation current by forming a first metal layer on the surface at the short part of a second low concentration semiconductor layer and a third semiconductor layer formed on the second semiconductor layer from the surface thereof. SOLUTION: A second low concentration semiconductor layer 2 of first conductivity type is formed on a first high concentration semiconductor layer 1 and a third high concentration semiconductor layer 3 of second conductivity type is formed in the second semiconductor layer from the surface thereof. A first metal layer 11 is then formed on the surface at the short part of third semiconductor layer 3 and second semiconductor layer 2 thus forming a diode. At the time of reverse recovery of the diode formed of the first, second and third semiconductor layers 1, 2, 3, residual carriers in the second semiconductor layer 2 beneath the third semiconductor layer 3 flow through the second low concentration semiconductor layer 2 into the first semiconductor layer 1. Since small number of residual carriers are pulled in, soft recovery is realized. |
