Paper TF-MoA4
Molecular Layer Deposition of Alkyl-Aromatic Polyamide Films

Monday, October 15, 2007, 3:00 pm, Room 613/614

Organic thin film materials with well controlled microstructure have significant applications in organic light-emitting devices, organic thin film transistors, organic photovoltaic cells, quantum devices, molecular electronics, biomaterial interfaces, and others. Molecular layer deposition (MLD) is a binary self-limited deposition process to form uniform and conformal polymer thin films with well controlled microstructure. We have recently investigated vapor-phase polymer MLD using (1, 4 butane diamine) and aromatic (terephthaloyl dichloride) polyamide. 1, 4 butane diamine and terephthaloyl dichloride were evaporated at room temperature and 70°C respectively. Growth on a variety of surfaces, including Au, Si-OH, Si-H, methyl-terminated Si, and amino-terminated Si, was investigated, with substrate temperature controlled between 70 and 150°C. An in-situ quartz crystal balance was used to monitor the adsorption and desorption behavior of the monomers. Generally, the deposition rate decreased as the reaction temperature increased. At 85°C, the thickness of the polyamide film measured using ellipsometry as a function of the number of deposition cycles results in a growth rate of 0.2 nm/cycle. Transmission infrared spectroscopy verified the characteristic polyamide peaks in the films. Contact angle measurements were carried out after each monomer dosing cycle resulting in expected changes in the surface energy with each half-cycle. The thermal stability, chemical inertness and capacitance properties of the deposited polymer thin film were also characterized. Results give insight into process requirements to achieve well controlled molecular layer deposition of organic films that include aromatic elements.