Bidirectional power device and manufacturing method thereof

Abstract

The invention discloses a bidirectional power device and a manufacturing method thereof. The bidirectional power device comprises: a semiconductor layer; a first doped region, which is located in thesemiconductor layer; a plurality of trenches of a first trench region, wherein the trenches are located in the first doped region and divide the first doped region into alternating first-type sub-doped regions and second-type sub-doped regions; a gate dielectric layer, that covers the side walls of the lower parts of the plurality of trenches of the first trench region; a shielding dielectric layer, that covers the side walls of the upper parts of the plurality of trenches of the first trench region; and grid conductors, which are located in the plurality of trenches of the first trench regionand make contact with the grid dielectric layer and the shielding dielectric layer separately, wherein each grid conductor comprises a control grid and a shielding grid which are connected, the control grid makes contact with the grid dielectric layer, the shielding grid makes contact with the shielding dielectric layer, the thickness of the shielding dielectric layer is inconsistent, and the thickness of at least a part of the shielding dielectric layer is greater than the thickness of the gate dielectric layer. According to the device, the voltage withstanding performance of the device is improved through the setting that the thickness of at least a part of the shielding dielectric layer is greater than the thickness of the gate dielectric layer.

Description

technical field [0001] The present application relates to the technical field of semiconductor manufacturing, and more specifically, to a bidirectional power device and a manufacturing method thereof. Background technique [0002] Bidirectional power devices are widely used in charging devices with a secondary charging function. Taking the lithium battery charging and discharging device as an example, when the lithium battery charging and discharging device continues to supply power to the terminal equipment to a certain extent, it is necessary to prevent the lithium battery from over-discharging to prevent the terminal equipment from stopping, and to charge the lithium battery in time. In the process of charging the lithium battery, the lithium battery also needs to supply power to the terminal equipment, and at the same time prevent the lithium battery from being overcharged. Therefore, in order to manage and control the charge and discharge state of the lithium battery, ...

AI Technical Summary

Problems solved by technology

However, the MOS process using a planar gate structure requires sufficient area to meet higher withstand voltage requirements, and at the same time, the conduction efficiency of the device is very low and the power consumption is large

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