Manufacturing method of trench isolation structure

Abstract

The invention discloses a manufacturing method of a trench isolation structure. The manufacturing method of the trench isolation structure comprises the following steps of: sequentially forming a patterned cushion layer and a patterned mask layer on a substrate, wherein the substrate comprises a storage unit region and a peripheral region; taking the patterned mask layer as a mask to remove a part of the substrate so as to form a plurality of trenches; forming a first liner on the substrate so as to cover the patterned mask layer, the patterned cushion layer and the surfaces of the trenches; removing the first liner for covering the patterned mask layer, the patterned cushion layer and the surfaces of the trenches in the peripheral region; after removing the first liner in the peripheral region, contracting inwardthe patterned mask layer, so that the contracting amount of the patterned mask layer in the peripheral region is greater than that of the patterned mask layer in the storage unit region; and forming insulating layers in the trenches to form a plurality of shallow trench isolation structures. Through the manufacturing method, a storage device element has better element characteristics and reliability.

Description

technical field

[0001] The invention relates to a method for manufacturing an isolation structure, and in particular to a method for manufacturing a shallow trench isolation structure. Background technique

[0002] With the advancement of semiconductor technology, the size of components is also continuously reduced. Therefore, in order to prevent the occurrence of short circuit between adjacent components, the isolation between components becomes very important. The more commonly used method today is the Shallow Trench Isolation (STI) process.

[0003] Generally, the formation of the STI structure includes forming a pad oxide layer and a patterned mask layer on the substrate, and then removing part of the substrate by using the patterned mask layer as a mask to form shallow trenches in the substrate. . Then, an insulating material is filled in the shallow trench to form a shallow trench isolation structure, and then the pad oxide layer and the patterned mask layer are rem...

Examples

Embodiment Construction

[0040] Generally speaking, since the peripheral area is usually used to form high-voltage elements and low-voltage elements, before the formation of the gate oxide layer, the peripheral area usually bears more wet etching than the memory cell area, and the high-voltage gate oxide layer in the peripheral area usually bears more wet etching. Thickness reduction is difficult or limited, so the corner thinning problem of the high-voltage gate oxide layer is also more serious in the peripheral region, and the low-voltage gate oxide layer may even grow in the recess. As a result, the device characteristics and reliability of the memory device are degraded. Therefore, the present invention forms the shallow trench isolation structure according to the characteristics of the peripheral area of ​​the memory element and the memory cell area, so as to avoid the angle thinning of the tunnel oxide layer and the gate oxide layer formed on the edge of the shallow trench isolation structure sub...

technical field

[0001] The invention relates to a method for manufacturing an isolation structure, and in particular to a method for manufacturing a shallow trench isolation structure. Background technique

[0002] With the advancement of semiconductor technology, the size of components is also continuously reduced. Therefore, in order to prevent the occurrence of short circuit between adjacent components, the isolation between components becomes very important. The more commonly used method today is the Shallow Trench Isolation (STI) process.

[0003] Generally, the formation of the STI structure includes forming a pad oxide layer and a patterned mask layer on the substrate, and then removing part of the substrate by using the patterned mask layer as a mask to form shallow trenches in the substrate. . Then, an insulating material is filled in the shallow trench to form a shallow trench isolation structure, and then the pad oxide layer and the patterned mask layer are rem...

Examples

Embodiment Construction

[0040] Generally speaking, since the peripheral area is usually used to form high-voltage elements and low-voltage elements, before the formation of the gate oxide layer, the peripheral area usually bears more wet etching than the memory cell area, and the high-voltage gate oxide layer in the peripheral area usually bears more wet etching. Thickness reduction is difficult or limited, so the corner thinning problem of the high-voltage gate oxide layer is also more serious in the peripheral region, and the low-voltage gate oxide layer may even grow in the recess. As a result, the device characteristics and reliability of the memory device are degraded. Therefore, the present invention forms the shallow trench isolation structure according to the characteristics of the peripheral area of ​​the memory element and the memory cell area, so as to avoid the angle thinning of the tunnel oxide layer and the gate oxide layer formed on the edge of the shallow trench isolation structure sub...

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