Chemically Distinct Adsorption of Sulfide Inhibitors for Multi-Surface Passivation and Area Selective Deposition

Area of Science:

• Materials Science
• Surface Chemistry
• Nanotechnology

Background:

• Area-selective atomic layer deposition (AS-ALD) enables precise thin film deposition and nanoscale patterning.
• Surface chemistry dictates ALD growth, allowing selectivity through inhibitors or promoters.
• Understanding inhibitor adsorption and interactions is key to controlling growth and passivation.

Purpose of the Study:

• To investigate the area-selective adsorption behaviors of two organosulfide inhibitors, dipropyl sulfide (DPS) and isopropyl sulfide (IPS).
• To evaluate the effectiveness of DPS and IPS in achieving area-selective atomic layer deposition on Cu, SiO2, and TiN surfaces.
• To elucidate the underlying mechanisms of selective adsorption and surface passivation using computational methods.

Main Methods:

• Experimental investigation of AS-ALD using DPS and IPS on Cu, SiO2, and TiN substrates.
• Density Functional Theory (DFT) calculations to model inhibitor adsorption and dissociation.
• Analysis of adsorption geometries and surface interactions to understand selectivity.

Main Results:

• DPS and IPS selectively adsorbed on Cu surfaces.
• DPS adsorbed on SiO2, while IPS did not, indicating differential surface reactivity.
• Neither inhibitor showed reactivity towards TiN surfaces.
• DFT calculations revealed substrate-dependent inhibitor dissociation and adsorption geometries.

Conclusions:

• DPS and IPS exhibit distinct adsorption characteristics crucial for AS-ALD.
• DPS can passivate multiple surfaces (Cu, SiO2), while IPS shows more selective adsorption.
• Substrate-specific inhibitor fragmentation influences the effectiveness of area-selective deposition and surface passivation.