Shalow groove isolation manufacturing method for preventing acute angle

Abstract

A process for preparing the shallow channel isolation without sharp angle includes sequentially generating SiON layer and masking layer on a semiconductor substrate, defining them to form a window to expose the substrate, generating spacer on the side wall of SiON layer and masking layer, generating a shllow channel on the semiconductor substrate, generating a lining oxide layer on the surface of shallow channel to form a beak-shaped lining oxide layer near the SiON layer, filling the isolation oxide layer in channel, and removing the masking layer and SiON layer. Its advantages are high thickness uniformity of oxide layer tunnel, and no parasitic transistor and electric leakage.

Description

technical field [0001] The invention relates to a shallow trench isolation manufacturing method, in particular to a shallow trench isolation manufacturing method avoiding acute angles. Background technique [0002] With the development of semiconductor manufacturing technology to submicron size, shallow trench isolation (STI; shallow trench isolation) has gradually replaced traditional semiconductor device isolation methods, such as local oxidation of silicon (LOCOS; local oxidation of silicon). Compared with LOCOS, STI has many advantages. For example, the STI method can make the semiconductor device isolation structure have a smaller width and thus have a higher device density. In addition, STI can improve the surface flatness, so it can effectively control the minimum line width (critical dimension) during lithography. [0003] Figures 1a to 1c It is a schematic cross-sectional view of a manufacturing method for manufacturing an STI structure according to a conventional...

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Problems solved by technology

Chatterjee et al. use the LOCOS method to form a bird’s beak (bird’sbeak) structure to avoid the sharp angle effect, but the manufacturing process is very complicated (IEEE, 1996)

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