Ion beam delayering system and method, and endpoint monitoring system and method therefor

Abstract

Described are various embodiments of an ion beam delayering system and method, and endpoint monitoring system and method therefor. In one embodiment, a method is described for monitoring an ion beam de-layering process for an unknown heterogeneously layered sample, the method comprising: grounding the sample to allow an electrical current to flow from the sample, at least in part, as a result of the ion beam de-layering process; milling a currently exposed layer of the sample using the ion beam, resulting in a given measurable electrical current to flow from the sample as said currently exposed layer is milled, wherein said given measurable electrical current is indicative of an exposed surface material composition of said currently exposed layer; detecting a measurable change in said measureable electrical current during said milling as representative of a corresponding exposed surface material composition change; and associating said measurable change with a newly exposed layer of the sample.

Description

[0001] related application [0002] This application is an International Patent Application claiming the benefit of Serial No. 62 / 795,369 filed January 22, 2019 and entitled "ION BEAM DELAYERING SYSTEM AND METHOD, AND ENDPOINT MONITORING SYSTEMAND METHOD THEREFOR" The benefit of priority of the United States Provisional Patent Application, the disclosure of which is hereby incorporated by reference in its entirety. technical field [0003] The present disclosure relates to ion beam milling, and in particular, to ion beam delayering systems and methods and endpoint monitoring systems and methods therefor. Background technique [0004] Removing layers in a sample such as a semiconductor chip involves removing very few and very thin layers of an integrated circuit, which for example contains metals and dielectrics, in order to reveal the underlying circuitry in a precise and controlled manner. ). [0005] Ion beam milling is one method used to delayer such samples. In genera...

AI Technical Summary

Problems solved by technology

However, endpoint detection methods such as SIMS have many disadvantages

For example, in ion beam milling, the large number of extracted material particles has the effect of producing noisy SIMS measurements

In this scenario, it is challenging to effectively use SIMS for endpoint detection

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