Analyzing the Effect of Sample Preparation on the MX2 Material for Atomic-resolved Transmission Electron Microscopy

Novel two-dimensional materials, especially semiconducting transition metal dichalcogenides (MX2, with M a transition metal and X a chalcogen) offer advanced functionality in complex and ultra-scaled integrated systems. In view of their compelling electronic, magnetic, and optical properties for a monolayer form, imec explores their integration for various applications and systems, in particular for advanced CMOS technologies in a beyond silicon roadmap [1].

Understanding the defects in MX2 materials is essential to comprehend their effects on electrical properties. Scanning transmission electron microscopy (STEM) and transmission electron microscopy (TEM) are versatile techniques that can provide insights into the type of defects and their quantity. However, sample preparation is a crucial factor in achieving accurate results.

Several steps are necessary to prepare a sample for TEM analysis without contamination or degradation. A clean transfer of the MX2 material onto the TEM grid without degradation is crucial.

This is a collaborative project between the MX2 Growth and TEM teams at IMEC. The teams will work closely together to improve the sample preparation process based on previous experience. This will involve defining, manipulating, and preparing samples for TEM. The impact of different conditions for sample preparation will be analyzed by examining the cleanliness of samples through TEM observations. All necessary training will be provided.

[1] J. M. Redwing, et al., ACS Nano 2021, 15, 2, 2532–2541.