Separation gate MOSFET structure and preparation method thereof

• Main Authors: XU YONGNIAN, LI XIAOHONG, YANG SHIHONG, YU YUANQIANG, MIAO DONGMING
• Format: Patent
• Language: Chinese; English
• Published: 30.01.2024
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

The invention relates to the field of MOS transistors, in particular to a split gate MOSFET structure and a preparation method thereof. The structure comprises a substrate; the X drift layers are sequentially stacked on the upper surface of the substrate; the X drift layers are respectively provided with a groove, the groove located in each drift layer active region is an active region groove, and the groove located in each drift layer terminal region is a terminal region groove; the arrangement directions of the active region trenches of two adjacent drift layers are vertical to each other; the terminal region grooves of two adjacent drift layers are arranged in a mutually stacked manner, the X terminal region grooves form a protection ring, and the protection ring surrounds the active region grooves of the X drift layers from the view angle in the Y direction; the bottom oxide layers are positioned in the active region grooves and the terminal region grooves of the drift layers; the bottom oxide layer is of