ELECTRONIC DEVICE OF VERTICAL MOS TYPE WITH TERMINATION TRENCHES HAVING VARIABLE DEPTH

摘要

An electronic device is integrated on a chip of semiconductor material having a main surface and a substrate region with a first type of conductivity. The electronic device has a vertical MOS transistor, formed in an active area having a body region with a second conductivity type. A set of one or more cells each one having a source region of the first conductivity, a gate region of electrically conductive material in a gate trench extending from the main surface in the body region and in the substrate region, and an insulating gate layer, and a termination structure with a plurality of termination rings surrounding at least part of the active area on the main surface, each termination ring having a floating element of electrically insulating material in the termination trench extending from the main surface in the chip and at least one bottom region of said semiconductor material of the second conductivity type extending from at least one deepest portion of a surface of the termination trench in the chip; the termination trenches have a depth from the main surface decreasing moving away from the active area.

主权项

1. A method, comprising:
manufacturing an electronic device in a semiconductor substrate, the substrate having a first surface and a second surface, the manufacturing including: forming at least one vertical MOS transistor in an active area of the substrate by: forming at least one body region extending in the substrate region from the first surface; forming one or more cells, for each cell:
forming a source region extending in the body region from the first surface;forming a gate trench extending in the body region;forming an insulating gate layer in the gate trench; andforming a gate region in the gate trench on the insulating gate layer; and forming a termination structure including a plurality of termination rings surrounding at least part of the active area on the first surface, for each termination ring:
forming at least one termination trench extending from the first surface in the substrate;forming the termination trenches with a depth from the first surface decreasing moving away from the active area; andforming at least one floating element of electrically insulating material in the termination trench.