Patent ID: 10923564

Abstract:
A super-junction structure is formed by alternately arrayed pluralities of N-pillars and of P-pillars. The P-pillars are formed by P-type materials filled in super-junction trenches. The super-junction trenches are formed in an N-type epitaxial layer, each formed by a bottom trench and a top trench stacked together. A side angle of the bottom trenches is greater than 90°, and the width of the bottom surface of each bottom trench is greater than that of the top surface of the trench. The side angle of the top trenches is smaller than 90°, and the width of the bottom surface of each top trench is smaller than the top surface of the trench. The super-junction trenches are of a waisted structure. The bottom trenches increase the bottom width of the super-junction trenches and improve the depletion of the bottoms of the N-pillars, increasing the breakdown voltage of the super-junction structure.