Investigation of electron beam nanolithography processes, mechanisms, and applications

Electron beam lithography (EBL) is the leading technology for versatile two dimensional patterning at the deep (10-100 nm) nanoscale. In addition to its reputation as an enabling technology for next generation advances in industry, its ease of use, accuracy, and cost has made it the technology of choice for rapid sub-micron prototyping in academia and research institutes worldwide. Advances in EBL processing have enabled sub-10 nm fabrication using a variety of materials under limited conditions. Repeatable processing at the deep nanoscale, particularly for dense nanostructure fabrication, requires a systematic quantitative study of all processing steps and their intricate interdependencies. In addition, developing future nanofabrication strategies with features approaching molecular length scales, requires a thorough examination of the molecular interactions taking place in EBL processing.;This research project investigates EBL processing using PMMA and ZEP resists through an in-depth quantitative study and analysis of process windows for dense grating fabrication. The effect of processing parameters from each EBL stage on process windows is thoroughly investigated. Through the study of process windows and contrast curves, EBL processing strategies are developed and high resolution processing limits in PMMA and ZEP resists are explored. Furthermore, the EBL development stage involving resist-solvent interactions is studied using molecular dynamics simulations in Accelrys Materials Studio software package, and analyzed using the Flory-Huggins polymer physics theory. Finally, optimized processing strategies for dense grating fabrication are demonstrated and techniques are employed for the fabrication of record ultra-narrow (8 nm) suspended SiCN cantilever structures and high aspect ratio polymer fabrication using novel SML resist.