Continued downscaling of electronic components, such as transistors and capacitors for advanced processors and memory chips, is ever harder and at the same time very important for our society. Atomic layer etching (ALE) is the most advanced etching process used in industry today. ALE enables material removal with atomic precision and is potentially damage-free for remaining material, which motivated its introduction to the industry. Together with atomic layer deposition (ALD) and atomic layer cleaning (ALC) ALE enables the new era of atomic-scale processing which is critical for the most advanced semiconductor technology nodes. In new technology nodes, the ALE is expected to be used together with advanced lithographical tools [1] and may enable new patterning schemes [2]. In this talk, we will present an overview of recent progress in ALE for manufacturing nanostructures with critical dimensions (CD) below 20 nm with the main focus on our work.

We discovered that by combining ALE and other already existing production technologies in a unique way, we cut the number of process steps increasing the throughput, saving on production costs, and lowering the CO₂ footprint [3, 4]. And we push the resolution limits also. This is enabled by the recently discovered ALE selectivity to inclined surfaces which turns walls of tapered structures into etch masks. The inclined surfaces can be readily fabricated by e.g. dry etching or epitaxial growth. This process provides access to the fabrication of extremely small structures in a very delicate, precise, and efficient way. All this by relying on changes in already existing equipment and processes, saving investments for the industry. We compete with already established semiconductor technologies and complement them at the same time.

References:

1. S. Khan, D.B. Suyatin, J. Sundqvist, et al. ACS Applied Nano Materials, 1, 6, 2476, DOI: 10.1021/acsanm.8b00509 (2018).
2. N. Marchack, K. Hernandez, B. Walusiak, J.-I. Innocent‐Dolor, S. Engelmann, Plasma Process Polym., DOI: 10.1002/ppap.201900008 (2019).
3. D. B. Suyatin, S. A. Khan, J. Sundqvist, et al. presented at 16th Int. Conf. on ALD, Dublin, Ireland, July (2016).
4. Sabbir Khan, Dmitry B. Suyatin, Jonas Sundqvist, A Method for Selective Etching of Nanostructures. WO2017157902A1 (2017).