Trench type vertical double-diffusion metal oxide semiconductor field effect transistor

Abstract

The invention relates to a VDMOS, which comprises a semiconductor substrate, a body region formed in the substrate and a source region formed in the body region, wherein a trench penetrates through the source region and the body region and extends to the substrate, each trench gate structure comprises a gate dielectric layer formed on the inner wall of the trench and a gate layer filled in the trench, a first interlayer dielectric layer, a first metal layer, a second interlayer dielectric layer and a second metal layer are sequentially stacked on the source region and each trench gate structure, one of the first metal layer and the second metal layer is a gate metal layer and is connected with each gate layer through a gate region contact hole, the other one is a source metal layer and isconnected with the body region through a source region contact hole, and the number N of the trench gate structures on the same side of the source region contact hole in each cell structure is greaterthan or equal to 2. According to the invention, the number N of the trench gate structures on the same side of the source region contact holes in the cell structure is larger than or equal to 2, so that large breakover current can be obtained under the condition that the occupied area of trench gates is small.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a trench type vertical double-diffused metal oxide semiconductor field effect transistor. Background technique [0002] The gate region of a Vertical Double Diffusion Metal Oxide Semiconductor Field Effect Transistor (VDMOS for short) penetrates the body region to form a trench gate structure, and the VDMOS with the trench gate structure is a trench type VDMOS. Trench VDMOS can eliminate parasitic junction field effect transistors, so it has a smaller on-resistance than ordinary VDMOS. Trench-type VDMOS usually contains multiple parallel cell structures, and the cell structure is defined as the smallest semiconductor structure repeating unit that constitutes VDMOS. The trench gate structure in the cell structure is generally a single trench gate structure formed on the outer edge of the cell structure to form a closed figure. For example, the trench gate structure can be formed int...

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Problems solved by technology

[0003] Based on this, it is necessary to propose a new trench-type VDMOS for the technical problem that the conduction current of the trench-type VDMOS is limited.

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