Vertical unipolar device periphery

摘要

A vertical unipolar component formed in a semiconductor substrate comprises a succession of fingers arranged in concentric trenches, separated from one another by silicon oxide only. The upper surface of the fingers of at least the innermost rank is in contact with a conductive layer coating portions of substrate between vertical conductive fingers and assembly. A vertical unipolar component formed in a semiconductor substrate (1) comprises vertical fingers (34) made of a conductive material surrounded with silicon oxide (3). Portions of the substrate present between the fingers and the assembly are coated with a conductive layer (4). The component periphery comprises a succession of fingers arranged in concentric trenches, separated from one another by silicon oxide only. The upper surface of the fingers of at least the innermost rank is in contact with the conductive layer. An independent claim is also included for a method for manufacturing a vertical unipolar component in a semiconductor substrate, comprising: forming in the semiconductor substrate first trenches (30) spaced apart by a first distance in the area corresponding to the actual unipolar component and second peripheral trenches spaced apart by a second distance shorter than the first distance at the component periphery; and performing a thermal oxidation so that a peripheral oxide layer forms between the first trenches and that the portions of the semiconductor substrate between the second trenches are completely oxidized.