| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a diode for electrostatic surge protection in which a leak current is not increased even if a break down voltage of the diode for electrostatic surge protection is reduced. <P>SOLUTION: P-type guard ring regions 12 are formed on one main face of an n-type silicon substrate 11. A plurality of grooves 17 in U-type cross section shapes and in almost rectangular plane shapes are arranged zigzag on the surface of the silicon substrate 11 surrounded by the guard ring regions 12. P-type base regions 13 are formed on the surface layer of the silicon substrate 11 comprising the grooves 17 surrounded by the guard ring regions 12 and on a surface layer at inner peripheral sides of the guard ring regions 12. PN junction J2 by the base regions 13 and the silicon substrate 11 becomes deep at bases of the grooves 17 and becomes shallow between the grooves 17. A polysilicon film 18 is formed on surfaces of the base regions 13 and inside the grooves 17. An anode electrode 15 formed of metal connected to a terminal A, aluminum or an alloy of it, for example, is disposed on the film 18 by electric contact. <P>COPYRIGHT: (C)2004,JPO</p> |
