Method for improving filling capacity of shallow-trench isolation dielectric thin film

Abstract

The invention discloses a method for improving the filling capacity of a shallow-trench isolation dielectric thin film. The method comprises the steps of receiving a pre-deposited thin film silicon wafer, etching a shallow-trench isolation structure in the silicon wafer, pre-treating the shallow-trench isolation structure, pre-filling a substrate to form a pre-filling layer, utilizing a flow type chemical gas phase deposition method for enabling the shallow-trench isolation structure to be partly filled so as to form a shallow-trench isolation oxide thin film after substrate pre-filling, performing deposition and covering on an upper layer thin film of the shallow-trench isolation structure partly filled through the flow type chemical gas phase deposition method, and executing high-temperature annealing treatment to improve the wet-process-resisting etching performance and the compactness of the shallow-trench isolation oxide thin film and the upper layer thin film. According to the method, the main technical problem of the flow type chemical gas phase deposition method in the application of shallow-trench isolation is successfully solved, the flow type chemical gas phase deposition method and the high-density plasma chemical gas phase deposition method or a high aspect ratio process are integrated together, and process windows not filled with cavities or gaps of the shallow-trench isolation thin film are increased.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to an integrated process for improving the filling capacity of shallow trench isolation dielectric films in semiconductor manufacturing, more specifically, the invention relates to a method for improving the filling capacity of shallow trench isolation dielectric films . Background technique [0002] Shallow Trench Isolation (STI) technology is an isolation method commonly used in integrated circuit manufacturing. It is used to fill shallow trenches with silicon oxide to isolate different semiconductor devices and avoid leakage currents and short circuits. As chip manufacturing technology moves towards smaller new process technology nodes, the width of shallow trenches continues to decrease, but the height of shallow trenches cannot be reduced proportionally, causing the aspect ratio of shallow trenches to decrease with the new process technology. Nodes increase. The inc...

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Problems solved by technology

Although the flow chemical vapor deposition method has excellent filling ability, there are two main technical problems in the deposition of shallow trench isolation oxide film (Flowable Oxide, FOX) by the flow chemical vapor deposition method: one is compared with high density Plasma process and high aspect ratio process, the wet etching speed of the film prepared by the flow chemical vapor deposition method is too fast, which is not conducive to controlling the film thickness in the wet etching process after filling, although the in-situ water vapor generation annealing process can improve The etch resistance of the film, the annealing process will also cause the silicon oxidation of the active area to reduce the size of the active area; the second problem is that the film prepared by flow chemical vapor deposition will have film shrinkage in the subsequent annealing process Phenomenon, the shrinkage of the large wide trench is more than that of the small narrow trench, which causes the elongated active region structure between the wide trench and the narrow trench to bend and deform towards the large trench (such as figure 1 shown), the degree of bending becomes more serious as the temperature of the annealing process increases

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