Surface breakdown bidirectional breakover protection component

Abstract

The present invention relates to a bidirectional breakover component including a lightly-doped N-type substrate, an upper P-type region extending over practically the entire upper surface of the component except its circumference, a lower P-type uniform layer on the lower surface side of the component, substantially complementary N-type regions respectively formed in the upper region and in the lower layer, a peripheral P-type well, an overdoped P-type region at the upper surface of the well, and lightly-doped N-type regions between the circumference of the upper region and the well.

What is claimed is:  
     
         1 . A bidirectional breakover component, including: 
 a very lightly-doped N-type substrate;    an upper P-type region extending over practically an entire upper surface of the component except its circumference;    a lower P-type uniform layer on a lower surface side of the component;    substantially complementary N-type regions respectively formed in the upper region and in the lower layer;    a peripheral P-type well;    an overdoped P-type region at an upper surface of the well; and    lightly-doped N-type regions between the circumference of the upper region and the well.    
     
     
         2 . A component according to  claim 1 , wherein the overdoped P-type region has the same level of doping as the upper region.  
     
     
         3 . A component according to  claim 1 , wherein the lightly-doped N-type regions have the same level of doping as the substantially complementary N-type regions.