| 摘要 |
PURPOSE:To permit punching through with only a depletion layer spreads a little and to protect favorably a gate by a method wherein the impurity concentration of an N-type diffused region is formed into low concentration and also, the distance between a Schottky junction electrode and an ohmic electrode is made shorter. CONSTITUTION:A protective diode 1 is constituted of a low-impurity concentration and one-conductivity type first diffused region 3 which is formed in a semiconductor substrate 2, a first electrode 4 which is Schottky-junctioned on one side of the first diffused region 3 and a second electrode 5 which is ohmic-junctioned on the other side of the first diffused region 3. A Schottky barrier diode 21 connected to a gate 1 is constituted of the first electrode 4 and the second electrode 5, and by forming the impurity concentration of the diffused region 3 into a low-impurity concentration, the spreading to the lateral direction of a depletion layer is improved, and furthermore, by adjusting the distance between the Schottky junction electrode 4 and the ohmic electrode 5...for example, if the distance between the electrodes 4 and 5 is shortened, a punch through becomes possible with only a depletion layer spreads a little. |
