Manufacturing method of shield gate trench power device

• Main Authors: XUE HUARUI, LI XIURAN, HUI YANI
• Format: Patent
• Language: Chinese; English
• Published: 17.09.2021
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

The invention provides a manufacturing method of a shield gate trench power device, which comprises the following steps of: providing a substrate with an epitaxial layer, forming a plurality of trenches in the epitaxial layer, and forming an angle of 87-93 degrees between the side wall of each trench and the surface of the substrate; executing a wet oxygen oxidation process to form at least part of the first dielectric layer to cover the inner wall of the trench; forming a shield gate in the trench; forming a second dielectric layer and a first gate oxide layer; forming a second gate oxide layer, the second gate oxide layer covering the inner wall of the first gate oxide layer, and the bottom corner of the second gate oxide layer being in a circular arc shape; and forming a grid electrode in the trench. The first dielectric layer is formed by using the wet oxygen oxidation process, the problem that a vertical trench is difficult to fill is solved, electric field distribution is improved and breakdown voltage