Trench type semiconductor power device with low gate resistance and preparation method thereof

Abstract

The invention relates to a trench type semiconductor power device with low gate resistance and a preparation method thereof, the semiconductor power device comprises an embedded trench type gate (250) with a titanium / titanium nitride / tungsten plug, an NSG layer (270) is arranged at the top, the arrangement of the embedded trench type gate (250) is that a standard trench gate is matched with the embedded trench type gate, or 10 standard trench gates are matched with the embedded trench type gate; and the number of the embedded trench type gate (250) is inversely proportional to the width of the unit standard trench gate and inversely proportional to the required gate resistance. The device and the preparation method thereof can reduce the internal gate resistance, simultaneously not affectthe improvement of the unit density, simplify the manufacture and be applicable to mass production. The trench type semiconductor power device can be used for a variety of trench type metal oxide semiconductor field effect transistors, such as P type and N type low-voltage devices and high-voltage devices, P type and N type IGBT, high-voltage integrated circuits and the like.

Description

technical field [0001] The present invention relates to a cell structure and device configuration of a power semiconductor device. More particularly, the present invention relates to a new and improved cell structure and device configuration for trench-type semiconductor power devices with low gate resistance. Background technique [0002] Conventional techniques for forming trenched gates and gates for high-density trenched metal-oxide-semiconductor field-effect transistor (Mosfet) devices are facing technical difficulties, as the undesirable internal gate resistance increases as the trench width decreases As a result, the switching speed becomes slower. Narrow trench widths result in high gate resistance due to reduced doped polysilicon in the trench region. High gate resistance can adversely affect the switching performance of the device and also reduce product reliability. [0003] refer to Figure 1A and 1B , a top view and a side cross-sectional view of a common Mo...

AI Technical Summary

Problems solved by technology

[0004] Disadvantages: When the trench width becomes smaller, the doped polysilicon in the trench area decreases, and the gate resistance increases, especially for the trench in the central area, which affects the switching speed of the device

[0006] Disadvantages: The source metal is divided into several pieces, which will increase the Ron value of the device due to the increase in the surface conduction resistance

[0009] Disadvantages: (i) process is difficult; (ii) threshold voltage is difficult to control US006930355 US patent US20060273382, Figure 4 :

[0012] Disadvantages: Due to the size limitation of the trench-type gate opening, the width of the trench is limited, which limits the cell density

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