| 摘要 |
PURPOSE:To obtain a static induction type thyristor especially suitable for an operation under a big electric current by a method wherein the static induction type thyristor can have an improved structure by improving the switching speed with an acceleration electric field created in such a way that an impurity slope is provided at a channel region. CONSTITUTION:An n<--> type region 19 whose impurity density is extremely low is formed so as to surround a source, and,at a place adjacent to the n<--> type region 19, an n-type region 20 whose impurity density is comparatively high and whose thickness in the cathodeanode direction is thin is formed. The impurity density of this n<--> type region 19 is low. This region 19 shows a comparatively flat potential profile, and is transformed under the influence of the potential distribution at the n-type region 20 at the anode side. In addition, within the n-type region 20 a comparatively steep potential slope is formed in the cathode- anode direction, and an electric field is generated in such a way that it strongly accelerates an electron moving to the anode from the cathode across a potential barrier. Because an intrinsic gate is formed at the n<--> type region 19 adjacent to the source region 12 and the electron which passed through the intrinsic gate is accelerated strongly, the moving time of the electron becomes short and the thyristor is quickly turned on. In addition, because the n-type region 20 whose impurity density is comparatively high is constituted so as to cover the p<+> type gate region, the voltage of a device in the forward direction can be improved. |
