Manufacturing method of shallow trench isolation structure

Abstract

The invention provides a manufacturing method of a shallow trench isolation structure. The manufacturing method comprises the steps of: providing a substrate; sequentially forming an oxide layer, a polycrystalline silicon layer, a mask layer and a bottom part anti-reflection coating on the substrate; sequentially etching the bottom part anti-reflection coating, the mask layer, the polycrystallinesilicon layer, the oxide layer and the substrate; forming a shallow trench in the substrate; cleaning the shallow trench; and filling the shallow trench with an isolation material to form the shallowtrench isolation structure. According to the manufacturing method of the shallow trench isolation structure, the shallow trench is cleaned to remove a polymer after the shallow trench is etched for isolation, thereby preventing the polymer from volatilizing and contaminating other wafers that are not etched, further preventing the production of particles affecting wafer etching in the subsequent steps, and finally improving the quality of wafer etching.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for manufacturing a shallow trench isolation structure. Background technique [0002] In the integrated circuit manufacturing process, the quality of the wafer (wafer) processing technology has a decisive influence on the working performance of the circuit. Among them, making shallow trench isolation (STI) is the front-end basic process of the entire integrated circuit processing. [0003] When the wafer is etching shallow trenches, a total of 25 wafers are placed on the wafer boat. At the beginning, the wafer boat is placed in the non-etching cavity (VCE), and then it is passed from the first wafer to the etching one by one. Etching is carried out in the cavity, and the gas used during etching is mainly HBr or Cl 2 or CF 4 , These gases are easy to react with the film to form a polymer that adheres to the wafer. When the wafer is etched and returned to the non...

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Problems solved by technology

[0003] When the wafer is etching shallow trenches, a total of 25 wafers are placed on the wafer boat. At the beginning, the wafer boat is placed in the non-etching cavity (VCE), and then it is passed from the first wafer to the etching one by one. Etching is carried out in the cavity, and the gas used during etching is mainly HBr or Cl 2 or CF 4 , These gases are easy to react with the film to form a polymer that adheres to the wafer. When the wafer is etched and returned to the non-etched cavity, the polymer adhered to the surface will volatilize, and then the non-etched The aluminum material on the surface of the etched cavity reacts, forming some particles that fall off and fall onto the wafer on the top layer. When the wafer is etched, the amount of etching is greatly affected, resulting in etching. If the quality is not up to standard, it is more likely that it will not be able to etch

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