Low-gate-resistance power MOSFET device with separated gate enhancement structure and method

Abstract

The invention provides a low-gate-resistance power MOSFET device with a separated gate enhancement structure and a manufacturing method of the device. The low-gate-resistance power MOSFET device comprises a first conductive type substrate, a first conductive type epitaxial layer and a groove structure, the groove structure comprises a control gate electrode and a separated gate electrode, the control gate electrode comprises a first gate electrode, a second gate electrode and a third gate electrode. The third gate electrode is located above the first gate electrode and the second gate electrode and is adjacent to the first gate electrode and the second gate electrode, a second conductive type well region is located above the first conductive type epitaxial layer, and a second conductive type heavily doped region is located at the upper part of the interior of the second conductive type well region. A first conduction type heavily doped source region is arranged above the second conduction type well region. The device structure has the characteristics of low gate capacitance and low gate resistance, the aims of high switching speed and low switching loss are achieved, and a low-gate-resistance metal oxide semiconductor field effect transistor with the separated gate enhancement structure is obtained.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and more particularly relates to a low-gate-resistance split-gate enhanced power MOSFET device and a manufacturing method thereof. Background technique [0002] Power management systems require power semiconductor devices to have low on-resistance and parasitic capacitance to reduce device conduction loss and switching loss. Split-gate VDMOS has become the mainstream low-voltage device used in power management systems due to its low power loss, fast switching speed, small parasitic capacitance, and good high-frequency characteristics. The Chinese invention patent 201910191166.9 of Qiao Ming, Wang Zhengkang, Zhang Bo, etc. and the US invention patent US16 / 536333 proposed a trench MOSFET with a split gate enhancement structure, which reduces the gap between the control gate and the split gate in the split gate trench device. The parasitic capacitance Cgs and the gate charge Qg. However, if...

AI Technical Summary

Problems solved by technology

However, if the control gate structure is too narrow, the gate resistance will be too large, and if the gate resistance value is too large, the switching loss of the device will be greatly increased.

[0003] Therefore, in view of the above problems, it is necessary to reduce the problem of excessive gate resistance caused by too narrow a control gate in a split gate enhancement structure, and it is against this background that the embodiments of the present invention appear

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