Patterned Atomic Layer Deposition on Scanning Tunneling Microscope constructed templates

A. Azcatl, J. Ballard, Y. Chabal, K.-J. Cho, D. Dick, J. Owen, R. Longo, S. McDonnell, G. Mordi, J. Randall, R. Wallace
Zyvex Labs, US

Keywords: atomic layer deposition, scanning tunneling microscopy, nanomanufacturing

Summary:

This research shows a process combining STM lithography with the well controlled technique of ALD, indicating a new process for using single-pass STM patterning 3-D structures with sub-nanometer dimensional control. The templating was done using hydrogen depassivation lithography from Si(100)-H, a process that has potential precision down to 1 Angstrom. Selective ALD chemistry was confirmed where titanium tetrachloride and water deposit on depassivated, but not passivated, Si(100) using chemically prepared samples. Hydrogen depassivation patterns were made using STM with feature sizes ranging from 20nm to 800nm. These samples went through the selective ALD process and were analyzed using AFM. 3 nm tall features were identified, in line with predictions, and linewidths down to 20nm in direct agreement with STM images before deposition. This technique has implications in ultra-fine pattern transfer for nanoelectronics, mechanical structure formation, and basic understandings into ALD growth.