<p>ABSTRACT: Atomic layer deposition (ALD) raises global interest
through its unparalleled conformality. This work describes new microscopic
lateral high-aspect-ratio (LHAR) test structures for conformality analysis of
ALD. The LHAR structures are made of silicon and consist of rectangular
channels supported by pillars. Extreme aspect ratios even beyond 10 000:1
enable investigations where the adsorption front does not penetrate to the end of
the channel, thus exposing the saturation profile for detailed analysis. We use
the archetypical trimethylaluminum (TMA)-water ALD process to grow alumina as a
test vehicle to demonstrate the applicability, repeatability and
reproducibility of the saturation profile measurement and to provide a
benchmark for future saturation profile studies. Through varying the TMA
reaction and purge times, we obtained new information on the surface chemistry
characteristics and the chemisorption kinetics of this widely studied ALD process.
We propose new saturation profile related classifications and terminology. </p>