| AVS 58th Annual International Symposium and Exhibition | |
| Thin Film Division | Monday Sessions |
| Session TF-MoM |
| Session: | Thin Films: Growth and Characterization I |
| Presenter: | Rakhi Patel, Colorado School of Mines |
| Authors: | R. Patel, Colorado School of Mines C.A. Wolden, Colorado School of Mines |
| Correspondent: | Click to Email |
Hybrid organic-inorganic nanolaminates combine the functionality of an inorganic material with the flexibility and mechanical integrity provided by the organic polymer layer. They are integral components in various applications serving as advanced dielectrics, flexible barrier coatings, and as optical components. This work focuses on the low temperature synthesis of alumina/silicone nanolaminates by plasma-enhanced chemical vapor deposition (PECVD) in a single chamber for dielectric applications.
Self-limiting synthesis of alumina was accomplished via pulsed PECVD at the synthesis temperature of ~ 100 °C using trimethyl aluminum (TMA) and oxygen as precursors. The deposition kinetics and film quality were evaluated as a function of precursor exposure, plasma power, substrate temperature, and pulse parameters. Film composition was assessed by using spectroscopic ellipsometry and Fourier transform infrared spectroscopy (FTIR). The deposition rate per pulse scaled with the degree of precursor exposure during the plasma off step. Through appropriate control of the TMA concentration and pulse duration, the depositing rate could be adjusted over a narrow range (1.6 – 2.8 Å/pulse). Alumina films deposited at 105 °C contained a very small concentration of hydroxyl impurities. Polymeric silicone-like coatings were deposited using hexamethyldisiloxane (HMDSO) and oxygen as precursors. A wide range of coatings, from inorganic SiO2-like films to flexible polymeric films could be deposited by appropriate control of parameters including the rf power, substrate temperature and working pressure. Growth rates as high as 100 nm/min were obtained for polymeric silicone films.
Alumina/silicone nanolaminates were constructed as a function of nanolaminate composition and dyad thickness. Precise control of nanolaminate construction was confirmed through field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The dielectric performance of these structures was examined by using capacitance-voltage and current-voltage measurements. The effective dielectric constant could be controlled by changing the alumina content of the nanolaminates, and modeling these structures as capacitors in series accurately described the observed variations in κ.