Method for preserving scanning electron microscope (SEM) sample

Abstract

The invention relates to the technical field of semiconductor technologies, and provides a method for preserving a scanning electron microscope (SEM) sample. The method includes the steps that the sample is provided first, the sample is placed into SEM equipment to be subjected to failure analysis, then the surface of the analyzed sample is coated with a protective layer used for isolating air, afterwards, the sample is placed in the atmospheric environment to be preserved, when the sample needs to be subjected to failure analysis again, the protective layer on the surface of the sample is eliminated, and finally the sample is placed into the SEM equipment to be subjected to failure analysis. The method for preserving the SEM sample is reliable, easy to implement and low in cost, the problem that the surface of the SEM sample is likely to be damaged or oxidized in the failure analysis process in the prior art is solved, the success rate of failure analysis can be improved by technicians in the field through the method, and the failure analysis cost is lowered.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for storing samples of a scanning electron microscope. Background technique [0002] Integrated Circuits (Integrated Circuit, IC) follow the evolution of Moore's Law, the integration level is continuously improved, and the feature size is continuously reduced. In the ever-shrinking device structure, the defects that cause device failure are getting smaller and smaller. Although various defects in most manufacturing processes can be caught by defect detection systems, it is impossible to tell the producer why these defects occur. Scanning Electron Microscope (SEM) is the most commonly used failure analysis equipment. SEM can be used to observe the sample cross section or surface in a subtle way. The magnification of SEM can range from thousands of times to hundreds of thousands of times, and the resolution can reach 3nm, so it can meet the needs of m...

AI Technical Summary

Problems solved by technology

However, if the copper metal layer of the sample has been exposed, it is very easy to oxidize in the air (such as Figure 4 shown)

To solve this problem, the samples are usually stored in a nitrogen cabinet or a vacuum cabinet, but this solution requires the purchase of professional equipment, which is expensive, and because it cannot be completely isolated from the air when placed in a nitrogen cabinet or a vacuum cabinet, sometimes it will Copper Oxidation Problems Occur

In addition, during the storage of all types of SEM samples, the surface of the SEM sample may also be damaged by some accidental contact, such as tweezers.

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