In-line depth measurements by AFM

A system for evaluating a region of a sample, the system comprising:

• a vacuum chamber;
• a focused ion beam (FIB) column configured to direct a charged particle beam into the vacuum chamber toward the sample;
• a scanning electron microscope (SEM) column configured to direct a charged particle beam into the vacuum chamber toward the sample;
• a sample support configured to hold a sample within the vacuum chamber during a sample evaluation process and move the sample between a field of view of the FIB column and the SEM column;
• an atomic force microscope (AFM) instrument configured to measure a height of features on the sample while the sample is positioned on the sample support;
• and
• a processor and a memory coupled to the processor, the memory including a plurality of computer-readable instructions that, when executed by the processor, cause the system to:
• transfer the sample into in the vacuum chamber;
• and
• acquire a plurality of two-dimensional images of a region of interest on the sample over a plurality of iterations of a delayering process by:
• (a) positioning the region of interest under a field of view of the FIB column;
• (b) milling a layer of material from the region of interest with the FIB column;
• (c) moving the region of interest under a field of view of the SEM column;
• (d) imaging the region of interest with the SEM column and measuring a depth of the milled layer in the region of interest with the AFM instrument;
• and
• repeating steps (a)-(d) a plurality of times without removing the sample from the vacuum chamber.

A non-transitory computer-readable memory that stores a plurality of computer-readable instructions for evaluating a region of interest on a sample by:

• transferring the sample into in a vacuum chamber of the sample evaluation tool that includes a focused ion beam (FIB) column, a scanning electron microscope (SEM) column, and an atomic force microscope (AFM) instrument;
• and
• acquiring a plurality of two-dimensional images of the region of interest over a plurality of iterations of a delayering process by:
• (a) positioning the region of interest under a field of view of the FIB column;
• (b) milling a layer of material from the region of interest with the FIB column;
• (c) moving the region of interest under a field of view of the SEM column;
• (d) imaging the region of interest with the SEM column and measuring a depth of the milled layer in the region of interest with the AFM instrument;
• and
• repeating steps (a)-(d) a plurality of times without removing the sample from the vacuum chamber.