The role of atomic oxygen in the decomposition of self-assembled monolayers during area-selective atomic layer deposition

Utilising self-assembled monolayers (SAMs) to achieve area-selective atomic layer deposition (AS-ALD) as an approach bottom-up nanofabrication has recently gained significant attention from the nanoelectronics industry. With continued downscaling of feature sizes, top-down processing can no longer reach challenging demands industry which requires conformal coating high aspect ratio vias and a reduction in misalignment errors multi-layered devices. In this work we attempt imitate effects ALD oxidation pulse experienced by SAMs during AS-ALD process exposing two different chain lengths functional groups, (3-trimethoxysilylpropyl)diethylenetriamine (DETA) octadecyltrimethoxysilane (OTMS), numerous controlled in-vacuo oxygen exposures with subsequent characterisation X-ray photoelectron spectroscopy (XPS). We monitor sequential removal deposited each successive exposure for both SAMs. The etch rate is observed be distinct SAMs, amino-terminated short DETA SAM reveals linear while OTMS exponential rate. results presented provide some insights into what characteristics are important choosing correct applications.