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

An ion beam de-layering system for de-layering an unknown heterogeneously layered sample, the system comprising:

• an ion beam mill for generating an ion beam during an ion beam de-layering process;
• an electrical conductor for grounding the unknown heterogeneously layered sample to allow a measureable electrical current to flow from the unknown heterogeneously layered sample, at least in part, as a result of said ion beam de-layering process;
• a current measuring apparatus operatively connected to said electrical conductor to monitor said measureable electrical current during said ion beam de-layering process;
• and
• a digital data processor operationally connected to said current measuring apparatus and operable to identify a measurable change in said measurable electrical current, wherein said measurable electrical current is indicative of an exposed surface material composition of a currently exposed layer, and wherein said measurable change is indicative of milling a newly exposed layer of the unknown heterogeneously layered sample.

A non-transitory computer-readable medium for monitoring ion beam de-layering of an unknown heterogeneously layered sample and having computer-executable instructions stored thereon to:

• acquire electrical current data from an electrical measuring device representative of an electrical current flowing from the unknown heterogeneously layered sample during ion beam de-layering;
• automatically identify a change in said electrical current data representative of a corresponding constituent material change in an exposed surface being milled upon said change exceeding a designated threshold;
• and
• output a signal to an ion beam mill controller to terminate said ion beam de-layering upon said change exceeding said designated threshold.