Integrated structure of trenches and manufacturing method thereof

Abstract

The invention discloses an integrated structure of trenches. A first trench and a second trench with large width difference are integrated on a semiconductor substrate at the same time; on the layoutstructure, the second trench is divided into a first sub-trench, a second sub-trench and a spacer region; the width difference between the first sub-trench and the first trench and the width difference between the second sub-trench and the first trench are small, and the depth difference among the first trench, the first sub-trench and the second sub-trench meets the required value after the anisotropic trench etching process; and the spacer region is removed by an isotropic anisotropic trench etching process to break through the first and second sub-trenches in the width direction and form asecond trench. The invention further discloses a manufacturing method of the integrated structure of the trenches. According to the invention, the defect that the trenches with large width differencehave large depth difference after the anisotropic etching process can be eliminated, the depth difference of the trenches with different widths is reduced or is not different, and when the integratedstructure of the trenches is applied to a trench gate semiconductor device, the breakdown voltage of the device can be improved or the specific on-resistance of the device can be reduced.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuit manufacturing, in particular to a groove integrated structure; the invention also relates to a method for manufacturing the groove integrated structure. Background technique [0002] The trench (Trench), that is, the gate structure of the trench gate MOSFET is formed in the trench, and the trench gate MOSFET generally includes a plurality of parallel cell structures, and each cell structure is formed in the device cell region. Such as Figure 1A Shown is the pad layout of the existing trench gate MOSFET; the pad is formed by the topmost front metal layer for connection with external circuits. Figure 1A A source pad 102 and a gate pad 101 are included. [0003] Such as Figure 1B shown, is Figure 1A The layout of the device unit area at the middle dotted line box 103 and the gate lead-out area outside the device unit area; it can be seen that a plurality of strip-shaped trenches 2...

AI Technical Summary

Problems solved by technology

[0008] The technical problem to be solved by the present invention is to provide an integrated structure of trenches, which can eliminate the defect that trenches with large width differences will have large differences in depth after anisotropic etching process, so that the depth of trenches with different widths Little or no difference

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