Novel Energetic Co-Reactant for Thermal Oxide Atomic Layer Deposition: The Impact of Plasma-Activated Water on Al2O3 Film Growth.

In the presented study, a novel approach for thermal atomic layer deposition (ALD) of Al2O3 thin films using plasma-activated water (PAW) as a co-reactant, replacing traditionally employed deionized (DI) water, is introduced. Utilizing ex situ PAW achieves up to a 16.4% increase in the growth per cycle (GPC) of Al2O3 films, consistent with results from plasma-enhanced atomic layer deposition (PEALD). Time-resolved mass spectrometry (TRMS) revealed disparities in CH4 partial pressures between TMA reactions with DI water and PAW, with PAW demonstrating enhanced reactivity. Reactive oxygen species (ROS), namely H2O2 and O3, are posited to activate Si(100) substrate sites, thereby improving GPC and film quality. Specifically, Al2O3 films grown with PAW pH = 3.1 displayed optimal stoichiometry, reduced carbon content, and an expanded bandgap. This study thus establishes "PAW-ALD" as a descriptor for this ALD variation and highlights the significance of comprehensive assessments of PAW in ALD processes.

Plasma-Assisted Nanofabrication: The Potential and Challenges in Atomic Layer Deposition and Etching.

The growing need for increasingly miniaturized devices has placed high importance and demands on nanofabrication technologies with high-quality, low temperatures, and low-cost techniques. In the past few years, the development and recent advances in atomic layer deposition (ALD) processes boosted interest in their use in advanced electronic and nano/microelectromechanical systems (NEMS/MEMS) device manufacturing. In this context, non-thermal plasma (NTP) technology has been highlighted because it allowed the ALD technique to expand its process window and the fabrication of several nanomaterials at reduced temperatures, allowing thermosensitive substrates to be covered with good formability and uniformity. In this review article, we comprehensively describe how the NTP changed the ALD universe and expanded it in device fabrication for different applications. We also present an overview of the efforts and developed strategies to gather the NTP and ALD technologies with the consecutive formation of plasma-assisted ALD (PA-ALD) technique, which has been successfully applied in nanofabrication and surface modification. The advantages and limitations currently faced by this technique are presented and discussed. We conclude this review by showing the atomic layer etching (ALE) technique, another development of NTP and ALD junction that has gained more and more attention by allowing significant advancements in plasma-assisted nanofabrication.