Preparation method of TEM sample

Abstract

The invention discloses a preparation method for a transmission electron microscope sample. The preparation method comprises the following steps: providing a device to be subjected to sample preparation and selecting a target region needing to be analyzed; preparing at least one section and enabling the section to be close to the target region; depositing protection layers on the corresponding positions of the target region; carrying out ion beam cutting on two surfaces deposited with the protection layers; when carrying out ion beam cutting along the direction perpendicular to any one surface of the two surfaces, stopping the cutting in the direction if finding that a hole is formed in the target region along the cutting direction; carrying out ion beam cutting along the direction perpendicular to the other surface and exposing the target region; and finishing the cutting of the device to be subjected to the sample preparation according to dimensional requirements to prepare a sample. According to the preparation method, the influences of curtain effect on the shape of the target region, caused by the hole, can be avoided effectively; defects are prevented from occurring and the reliability of sample analysis is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor device analysis, in particular to a method for preparing a transmission electron microscope sample. Background technique [0002] Transmission electron microscope (TEM, TEM for short) has become the most important tool for structure and material analysis in advanced process semiconductor fabs due to its ultra-high resolution and strong analysis functions. [0003] At present, the main TEM sample preparation equipment is the dual-beam ion beam system (DB-FIB) integrating FIB (Focusedion beam, focused ion beam) and SEM (Scanning electron microscope, scanning electron microscope). The electron beam can be used for synchronous observation to ensure the accuracy of the sample preparation position. [0004] After the semiconductor wafer is produced, due to various reasons such as structure or process, some small holes (such as holes between polysilicon sidewalls) will be formed inside the wafer. ...

AI Technical Summary

Problems solved by technology

When the observation object to be analyzed on the wafer is located below the hole, the observation quality of the TEM will be affected by the curtain effect and will be reduced, or even impossible to observe

[0005] figure 1 There is a hole 12 above the analysis target position 11 in the sample. When the ion beam cuts the sample from top to bottom, due to the existence of the hole 12, there will be an impact area 13 below it, resulting in damage to the analysis target position 11, as figure 2 TEM photograph of the sample

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