Work

Using a Heavy Inert Diffusion Additive for Superconformal Atomic Layer Deposition

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide The shrinking of device nodes increases the demand for deposition processes to seamlessly fill nanometer-scale features. Despite the precision of atomic layer deposition (ALD), it cannot deposit in a V-shaped fashion, which is characteristic of superconformal thin-film deposition. We propose a strategy for superconformal ALD by adding a heavy inert gas as a diffusion additive. We show that the step coverage in an 18:1 aspect ratio feature increased from 1 to 1.6 with the addition of Kr in an ALD process for AlN from Al(CH 3 ) 3 and NH 3 . We speculate that the heavier Kr (84 amu) promotes diffusion of the lighter NH 3 (17 amu) down the trenches. Consequently, NH 3 molecules are pushed to the trench bottom, resulting in a lower growth per cycle at the trench openings. Further studies are needed to understand the effect of Kr, but we foresee that this approach to superconformal ALD is applicable to many ALD processes.

Source: The Journal of Physical Chemistry Letters

DOI: 10.1021/acs.jpclett.4c03545

Authors: Arun Haridas Choolakkal, Pamburayi Mpofu, Pentti Niiranen, Jens Birch, Henrik Pedersen

Institution: Linköping University

Language: English

Topic: Semiconductor materials and devices

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funders: Linköpings Universitet, Vetenskapsrådet