Method for preparing transmission microscope samples on basis of non-precision positioning

Abstract

The invention discloses a method for preparing transmission microscope samples on the basis of non-precision positioning, and belongs to the technical field of semiconductors. The method includes providing failure analysis chips and positioning and labeling failure points in the failure analysis chips to obtain labeled zones; cutting a side of each labeled zone to form first wedge-shaped cavitiesand thinning the sections, which are close to the labeled zones, of the first wedge-shaped cavities until the failure points can be observed; forming protective layers on the sections where the failure points are observed; cutting the other side of each labeled zone to form second wedge-shaped cavities and thinning the sections, which are close to the labeled zones, of the second wedge-shaped cavities until primary samples with preset thicknesses are obtained; carrying out U-shaped cutting-off on the bottoms of the primary samples and then thinning the primary samples to obtain the transmission microscope samples. The method has the advantages that the failure points can be effectively prevented from being cut by mistake, each cut surface with the corresponding failure points can be prevented from being damaged or stained by splashing in follow-up processes, accordingly, the sample preparation success rate can be increased, and observation results can be improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a sample preparation method for a transmission electron microscope based on inaccurate positioning. Background technique [0002] The failure of integrated circuits is inevitable in the process of development, production and use. With the continuous improvement of people's requirements for product quality and reliability, failure analysis is becoming more and more important. Chip failure analysis can help IC designers find design defects, mismatch of process parameters, or improper design and operation; at the same time, failure analysis is a necessary means to determine the failure mechanism and can provide effective fault diagnosis. Necessary information provides necessary feedback for design engineers to continuously improve or repair chip design to make it more consistent with design specifications; failure analysis can also evaluate the effectiveness of different test...

AI Technical Summary

Problems solved by technology

For the type of failure analysis that cannot accurately locate the failure point (defect), it is necessary to use a focused ion beam microscope to observe the sample while cutting, and in this process, there is usually one side of the sample that has been cut to failure point, but there is a thicker residue on the other side. At this time, a high-current ion beam is required to thin it, and the side that has reached the failure point will be damaged or sputtered by the ion beam, which will affect the subsequent transmission of electrons. Microscope (Transmission Electron Microscope, TEM) observation and analysis of failure point

At the same time, there is also the risk of miscutting due to insufficient positioning accuracy of the failure point

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