Preparation method of TEM sample of nickel metal silicide

Abstract

The invention discloses a preparation method of a TEM sample of a nickel metal silicide. The method includes steps of: 1) providing a chip, wherein the nickel metal silicide is formed in selected zones in a device layer and a semiconductor substrate interface of the chip; 2) forming a metal protective layer so as to completely cover a target zone that requires TEM analysis; 3) cutting the TEM sample used for TEM analysis by means of ion beam; 4) turning the chip to a certain degree, and performing ion bombarding to the semiconductor substrate layer of the chip by means of the ion beam to completely amorphize the semiconductor substrate layer. The method can improve the TEM contract imaging difference between the semiconductor substrate layer and the TEM sample, and can form the TEM samplewhich allows clear imaging of the nickel metal silicide in a TEM mode, thereby reducing TEM observation time and reducing observation cost of the sample.

Description

technical field [0001] The invention relates to a method for manufacturing a semiconductor integrated circuit, in particular to a method for preparing a transmission electron microscope (TEM) sample of nickel metal silicide. Background technique [0002] TEM is a very important analytical tool in materials science research. It can perform morphology analysis, structural analysis and composition analysis of samples. It has an extremely wide and increasingly important application in the field of integrated circuit analysis. Focused ion beam (FIB) Sample preparation is the most important TEM sample preparation method in the semiconductor field. [0003] With the improvement of chip technology nodes, nickel silicide, namely nickel metal silicide, is used in integrated circuit manufacturing processes, and the phenomenon of chip failure caused by structural defects of nickel silicide (NiSi) is also increasing. The conventional method of preparing TEM samples by FIB, in order to a...

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Problems solved by technology

Depend on figure 1 As can be seen from the TEM photographs, it can only be seen that the nickel metal silicide is located within the area of ​​the dotted circle 104, but the nickel metal silicide cannot be distinguished from the silicon substrate 101, so it is impossible to realize the detection of the nickel metal silicide. Analysis of structural defects

[0004] Existing methods can only analyze NiSi morphology by scanning transmission electron microscope (STEM) high-angle annular dark field detector (HAADF) imaging, but it will greatly increase the cost of TEM observation and reduce the use efficiency of the machine

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