Preparation method of electron microscope scanning sample

Abstract

The invention discloses a preparation method of an electron microscope scanning sample, which comprises the following steps: forming a protective layer on a chip area to be sampled; imaging the protective layer to form positioning figures of several rectangles; forming a location hole on the positioning figure; filling the location hole to form a positioning column; cutting the area to be sampled and then taking out, forming a coarse sample in a cuboid shape; thinning the coarse sample along Y direction, observing the coarse sample by electron beam until the positioning column is exposed, and forming the electron microscope scanning sample. By controlling the sample thickness and thinning process of the positioning column, the sample thickness can be accurately controlled as the required thickness, and sample preparation time can be saved.

Description

technical field [0001] The invention relates to the fields of semiconductor manufacturing technology and material analysis, in particular to an electron microscope scanning sample preparation method. Background technique [0002] At present, with the continuous development of Moore's law, it is an effective method to take the stress of the channel region into consideration in the process of smaller and smaller line widths. NBD (Nano beam diffraction) is one of the effective methods to measure the stress distribution in the channel region so far, and it provides effective help for the research and development of stress in the process of advanced process development. [0003] In the prior art, NBD samples are usually prepared using FIB (Focus Ion Beam, focused ion beam). First, the sample to be processed is cut and taken out. At this time, the thickness of the sample does not reach the required thickness, and then it is thinned to the required thickness by FIB. Thickness, dur...

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Problems solved by technology

[0004] Using such a method of preparing samples, on the one hand, measuring the thickness of the top of the sample every time will make the preparation time of the entire sample longer, which affects the efficiency; on the other hand, the control of the thickness of the sample is realized by controlling the thickness of the top of the sample Therefore, it is not possible to accurately determine whether the actual thickness of the sample area to be analyzed has reached the predetermined thickness, which directly affects the accuracy of the NBD results, resulting in low repeatability of the final NBD results

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