| 摘要 |
PURPOSE:To improve the smoothness of Schottky barrier interface by forming the thin part of a first conductivity type of layer, using hydrofluoric acid, nitric acid, and acetic acid as the mixed liquid at a fixed mixture ratio, and specifying the etching speed at a specified value or under. CONSTITUTION:The center of the n-type silicon layer 2 of a silicon substrate, which has the n-type silicon layer 2 made by epitaxial growth on an n<+>-type silicon substrate 1, is removed, using etchant where fluoric acid, nitric acid, and acetic acid are mixed at a rate of 1:3:1. Next, a guard ring layer 3 is made by selectively diffusing impurities to the circumference of the removed section, and a metallic layer 5 is brought into contact with the whole surface of the etching face 6 of the n-type silicon layer 2 and one part of a p layer so as to form a Schottky barrier between it and the n-layer 2. The etching speed at the time of thinning the center of the n-type silicon layer 2 is made 0.06mum/sec or under by adjusting the liquid temperature. Hereby, the reverse current can be reduced. |
