As the semiconductor industry paces toward 0.15-micron feature size and below, the visibility of structures becomes a challenge. As a result, the use of higher precision metrology equipment such as FESEM, STEM, TEM and SCM becomes a necessity. TEM analysis today is a less common methodology of analysis. This is due to the time and effort required for the analysis as well as the difficulty of the sample preparation. This publication will share the experience gained in sample preparation for challenging applications such as STEM, TEM and SCM. The main driver will be the focus on short turnover time and high success rates.
In order to perform high-resolution analysis, samples should be transparent to electrons. Optimal thickness would be in the range of 20 to 120 nm (1). Pre-preparation of sample for advanced imaging will determine the final step method required. We used the automated polishing technique for sample preparation and reached 1 to 2 micron thickness.