Cross-Section Sample Preparation of a Free-Standing Thin-Film Coupon for Transmission Electron Microscopy Analysis

A method for preparing a cross-section sample from a free-standing thin-film coupon suitable for transmission electron microscopy analysis has been successfully developed. The free-standing coupon presented a significant challenge for the preparation of a cross-section sample. A stack consisting of a silicon wafer, thin-film coupon, and glass coverslip was epoxied together, providing both support for thin film and enough surface area to handle the specimen during the sample preparation procedure. The tripod polisher wedge technique was used to thin the cross-section sample to 2 to 5 μm in thickness. This produced a sample with the required structural integrity. Final thinning was accomplished using an ion mill. This technique showed no artifacts introduced from the sample preparation procedure.