Manufacturing method of shallow trench structure

Abstract

The invention relates to a manufacturing method of a shallow trench structure, which comprises the following steps of: providing a semiconductor substrate and forming a shallow trench on the semiconductor substrate; forming an oxide sacrifice layer in the shallow trench; removing the oxide sacrifice layer; forming a substrate oxide layer in the shallow trench; and forming a filling oxide layer for filling the shallow trench on the substrate oxide layer. Through the technical scheme, a corner at the top end of the shallow trench can be rounded in the forming process, thereby improving the stress environment in the shallow trench, avoiding the damage of a subsequent process to the shallow trench, improving the electrical performance of a semiconductor device and enhancing the yield of a semiconductor product.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for manufacturing a shallow trench structure. Background technique [0002] The development direction of semiconductor integrated circuits is to increase density and shrink components. In the manufacture of integrated circuits, the isolation structure is an important technology, and the components formed on the silicon substrate must be isolated from other components. With the advancement of semiconductor manufacturing technology, shallow trench isolation (Shallow Trench Isolation, STI) technology has gradually replaced other isolation methods such as local oxidation of silicon (LOCOS) used in traditional semiconductor device manufacturing. [0003] The manufacturing method of the existing shallow trench isolation structure generally includes: oxidizing the silicon wafer in a high-temperature oxidation furnace tube, forming a pad oxide layer (Pad Oxi...

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Problems solved by technology

In the process of forming the filled oxide layer, the plasma will continuously bombard the substrate oxide layer, especially for the sharp part of the substrate oxide layer located at each corner of the shallow trench, the plasma erosion will be more obvious, and the film The thickness of the layer will be thinned, and it may even be pierced and then destroy the silicon substrate under the substrate oxide layer, resulting in leakage current, reducing the isolation characteristics of the shallow trench, and resulting in the failure of the final semiconductor device. decline in quality

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