Font Size: a A A

Interfacial electrochemistry and surface characterization: Hydrogen terminated silicon, electrolessly deposited palladium and platinum on pyrolyzed photoresist films and electrodeposited copper on iridium

Posted on:2004-03-06Degree:Ph.DType:Dissertation
University:University of North TexasCandidate:Chan, RaymondFull Text:PDF
GTID:1461390011964996Subject:Chemistry
Abstract/Summary:
Hydrogen terminated silicon surfaces play an important role in the integrated circuit (IC) industry. Ultra-pure water is extensively used for the cleaning and surface preparation of silicon surfaces. This work studies the effects of ultra-pure water on hydrogen passivated silicon surfaces in a short time frame of 120 minutes using fourier transform infrared spectroscopy - attenuated total reflection techniques. Varying conditions of ultra-pure water are used. This includes dissolved oxygen poor media after nitrogen bubbling and equilibration under nitrogen atmosphere, as well as metal contaminated solutions. Both microscopically rough and ideal monohydride terminated surfaces are examined.; Hydrogen terminated silicon is also used as the sensing electrode for a potentiometric sensor for ultra-trace amounts of metal contaminants. Previous studies show the use of this potentiometric electrode sensor in hydrofluoric acid solution. This work is able to shows sensor function in ultra-pure water media without the need for further addition of hydrofluoric acid. This is considered a boon for the sensor due to the hazardous nature of hydrofluoric acid.; Thin carbon films can be formed by spin coating photoresist onto silicon substrates and pyrolyzing at 1000°C under reducing conditions. This work also shows that the electroless deposition of palladium and platinum may be accomplished in hydrofluoric acid solutions to attain palladium and platinum nanoparticles on a this film carbon surface for use as an electrode. Catalysis of these substrates is studied using hydrogen evolution in acidic media, cyclic voltammetry, and catalysis of formaldehyde. X-ray diffractometry (XRD) is used to ensure that there is little strain on palladium and platinum particles.; Iridium is thought to be a prime candidate for investigation as a new generation copper diffusion barrier for the IC industry. Copper electrodeposition on iridium is studied to address the potential of iridium as a copper diffusion barrier. Copper electrodeposition is studied using a current-transient technique to obtain insight into the nucleation and growth mechanism. Copper on iridum was annealed up to 600°C. X-ray photoelectron spectroscopy and XRD confirm that electrodeposited copper exists in a metallic state. XRD shows that copper exists in the characteristic face-centered cubic (111) form. XRD also confirms the stability of the copper-iridium interface with no new peaks after annealing, which is indicative that no interaction occurs. Scanning electron microscopy, and Scotch® Tape peel tests confirm the uniformity and strength of copper on iridium even after annealing to 600°C.
Keywords/Search Tags:Copper, Terminated silicon, Iridium, Hydrogen, Palladium and platinum, Surface, Ultra-pure water, Electrode
Related items