Method for isolating shallow trench from active region

Abstract

The invention discloses a method for isolating a shallow trench from an active region. The method for isolating the shallow trench from the active region comprises steps of providing a substrate, forming a shallow trench structure having a preset shape on the substrate, forming an isolation oxide layer on a surface of the shallow trench, forming a blocking layer on one side of the isolation oxide layer which is deviated from the shallow trench structure, depositing a film inside the shallow trench structure and performing annealing processing. Through arrangement of the isolation oxide layer and the blocking layer structure, the method for isolating the shallow trench from the active region removes a chemical reaction between the deposited film and the substrate during an annealing process so as to protect the size of the substrate and avoid the loss of the area of the active region.

Description

technical field [0001] The invention relates to the technical field of semiconductor technology, and more specifically, relates to a method for isolating an active region by a shallow trench. Background technique [0002] With the continuous development of science and technology, the feature size of semiconductor devices is gradually decreasing. Although the existing multi-step deposition-etching can improve the filling ability of HDP (High-Density-Plasma, high-density plasma chemical vapor deposition) , but it will make the process extremely complicated, and the deposition rate will be slow. As the number of cycles increases, the damage to the substrate caused by etching will be more serious. [0003] HARP (High-Aspect-Ratio-Process, high aspect ratio process) adopts TEOS Ramp up technology to obtain a faster growth rate under the condition of ensuring the filling capacity, making HARP gradually replace the HDP process and become the mainstream filling technology in the mar...

AI Technical Summary

Problems solved by technology

[0004] However, in the prior art, after the shallow grooves of the substrate are formed, the filled thin film material will react chemically with the substrate during the annealing process, which effectively reduces the size of the substrate and causes active area loss

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