Method for making shallow gully insulation of dynamic random access memory

Abstract

A manufacturing method of a shallow trench isolation (STI) used for a dynamic random access memory comprises the steps of forming an active region and a trench with an oblique angle of over 85 DEG on a silicon substrate; forming a first silicon oxide thin substrate inside the trench; forming a silicon nitride thin substrate on the first silicon oxide thin substrate; forming a second silicon oxide thin substrate on the silicon nitride layer; high-temperature annealing; and depositing high-density plasma silicon oxide. The inventive method can reduce the electrical leakage quantity of the dynamic random access memory based on the original basic process, so as to improve the retention time.

Description

technical field [0001] The invention relates to a manufacturing method of a semiconductor device, in particular to a manufacturing method of shallow trench isolation of a dynamic random access memory (DRAM) with low electric leakage. Background technique [0002] How to effectively reduce device leakage current to meet applications in different fields has always been a major challenge faced by the development of high-end CMOS processes. For dynamic random access memory, its specific working principle determines that the leakage current of the device is crucial to the time of data storage, thus playing a decisive role in the quality of the final product. [0003] As the line width of semiconductor devices shrinks to meet the development trend of faster speed and higher integration, some leakage currents that were previously negligible began to affect or even dominate the leakage performance of the entire device, making the line width of the leakage level under the same proces...

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However, the above methods are highly targeted and not universal

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