| 摘要 |
PURPOSE:To obtain a high speed diode with a limited reverse recovery time and a small value of du/dt by providing a p layer in a plurality of recesses formed in an N<+> layer at a thickness less than the layer in a P<+>NN<+> junction structure. CONSTITUTION:SiO210 is provided like an island in an N type Si 1. A P<+> layer 2 is made thereinto by B diffusion and N1<+>3 by P diffusion and undergoes heat treatment in O2. A window 9' is teched through the SiO210' thus formed to make a P layer 9 by B diffusion. New SiO210'' is formed entirely and selectively left on the P<+> layer 2 and the p layer 9. Then N2<+> layer 4 is made by P diffusion. Then, the SiO210'' on the layer 2 is removed and Au is deposited to attach an Al electrode thereto while an support electrode for W is soldered on the layer 4 side. A P<+>-N junction is molded in a negative bevel to complete. With such an arrangement, the interposition of the P layer 9 allows a carrier in a B region outside an extent of a depletion layer to be taken out of the P layer 9. This provides a high speed diode with a quick reverse recovery and a small value of di/dt in a such a broad range of a bias voltage as 2/3-1/20 of the rated voltage. This is the same with the N<+>PP<+> structure. |
