Power semiconductor with polysilicon structure at bottom of trench and method for manufacturing same

Abstract

The invention relates to a power semiconductor with a polysilicon structure at the bottom of a trench and a method for manufacturing the same. The power semiconductor comprises a first conduction type substrate, the trench, a heavy-doping polysilicon structure, a gate polysilicon structure and a gate dielectric layer, wherein the trench is formed inside the substrate; the heavy-doping polysilicon structure is positioned at a lower part of the trench, and at least one side edge of the heavy-doping polysilicon structure is in direct contact with the substrate; the gate polysilicon structure is positioned at an upper part of the trench; the gate dielectric layer is positioned between the gate polysilicon structure and the heavy-doping polysilicon structure; and the doping of the heavy-doping polysilicon structure diffuses outwardly to form a heavy-doping region.

Description

technical field [0001] The invention relates to a power semiconductor and a manufacturing method thereof, in particular to a power semiconductor with a heavily doped polysilicon structure at the bottom of a groove and a manufacturing method thereof. Background technique [0002] Compared with the traditional planar power semiconductors, the conduction current flows along the direction parallel to the surface of the substrate, while the trench power semiconductors set the gate in the trench to change the position of the gate channel, so that the conduction Current flows in a direction perpendicular to the substrate. Therefore, the size of the components can be reduced, and the integration of the components can be improved. Common power semiconductors include metal oxide semiconductor field effect transistors (MOSFETs), insulated gate diode transistors (IGBTs), and the like. [0003] The main energy loss of power semiconductors during operation includes conduction loss from ...

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Problems solved by technology

However, in order to improve its input capacitance (Ciss) and feedback capacitance (Crss), the complexity of the manufacturing process is often increased, resulting in an increase in manufacturing cost

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