Ring‐Opening of Cyclosiloxanes Induced Etching Amplification for Area Selective Deposition of SiOC Films

Self‐aligned patterning via area selective deposition (ASD) is promising for circumventing the overlay variation in photolithography for advanced nanomanufacturing. However, completely reversing the area selectivity when film growth is more favorable on the target non‐growth surface (NGS) than the target growth surface (GS) remains a daunting challenge even with etching incorporated. Here, we report an etching amplification strategy for ASD. We identified ring‐opening of 1,3,5‐trivinyl‐1,3,5‐trimethylcyclotrisiloxane (V 3 D 3 ) on CoO x surface by in‐situ diffuse reflectance infrared Fourier transform spectroscopy. This reaction enhances the plasma etching rate for V 3 D 3 polymer by 243%. In‐situ quartz crystal microbalance showed higher mass uptake on target NGS of CoO x than target GS of SiO 2 during deposition, yet plasma etching fully removes adsorbed species on target NGS. Accordingly, we achieved ASD of SiOC film (ca. 18.36 nm thick) with nearly 100% selectivity on pre‐patterned Co/SiO 2 substrates. This work sheds light upon etching amplification by precursor isomerization for developing highly selective ASD processes.