Novel trench isolation groove for filling trench

Abstract

The invention discloses a novel trench isolation groove for filling a trench and belongs to a micro electro mechanical system (MEMS) and a micro processing technology. According to the trench isolation groove provided by the invention, the distance between any point on the inner wall surface and the outer wall surface is respectively not greater than d, wherein the d is the width of the trench isolation groove. The trench isolation groove meeting the technical characteristics has diversified forms. The invention provides a plurality of specific embodiments. The corner shape of the trench isolation groove is directly changed, and thus the phenomenon that a small unfilled part at the corner of a rectangular groove appears is avoided and the groove corner can be ensured to be completely filled. Although etching ions rebound from the bottom surface to cause secondary etching on the side wall, the corner of the rectangular trench is of a circular arc and the like; and the distance between the inner wall surface and the outer wall surface is smaller than or equal to 2mu m and is equal to the distance between the two sides of the rectangular groove, so that no clearance in filling is ensured.

Description

Technical field: [0001] The invention mainly belongs to micro-electromechanical system (MEMS) and micro-machining technology, and specifically relates to the special shape of a rectangular channel isolation groove at a right-angle corner. Background technique: [0002] In MEMS technology, there are often situations where device surfaces need not only mechanical connection but also electrical isolation. Existing methods are usually realized by trench isolation trenches with a rectangular cross-section. In the trench isolation trenches, corresponding trenches are first etched on the device, and then a layer of silicon dioxide is grown on both side walls of the trenches as The insulating layer, which is filled with polysilicon material, plays the role of mechanical connection of the isolated part of the device surface. However, since the width of the rectangular groove at the right-angled corner is larger than that at the parallel part, such a trench isolation trench with a re...

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Problems solved by technology

[0005] The purpose of the present invention is: in order to solve the problem of incomplete filling in the existing surface rectangular trench filling, the present invention proposes several new shapes of trench isolation trenches, so as to achieve a satisfactory degree in the process of polysilicon filling trenches

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