| 摘要 |
PURPOSE:To contrive to attain low loss, high speed, and high reliability, by a method wherein a P-type region is made so that the absolute value of its surface concentration may be lower than that of the impurity concentration of an N-type substrate; an Al layer electrode is formed over the surface of that region; its depth is kept at less than the specific ratio of the thickness of the low impurity concentration layer thereunder; further, with the impurity concentration of the N-type substrate controlled within a specific range, Ni and Ag electrode layers are directly adhered. CONSTITUTION:An N-type low-concentration impurity layer 15 is formed on one surface of an N-type semiconductor substrate 11 with a impurity concentration of 1X10<17>-1X10<19>atoms/cm<3>, and a P-type region 13' having a depth of 1/3 or less of the thickness of this layer 15 and a lower impurity concentration than that of the substrate 11 is provided. The first electrode 14 of Al is adhered over this P-type region 13', and the second electrode 17 containing Ni and Ag is provided over the bottom of the substrate 11. |
