Anthony J Muscat

Anthony J Muscat

Department Chair, Chemical and Environmental Engineering
Professor, BIO5 Institute
Professor, Chemical and Environmental Engineering
Primary Department
Department Affiliations
Contact
(520) 621-6162

Research Interest

Research Interest
Dr. Anthony Muscat's group's research interests are in surface chemistry, specifically the chemical processes used to clean, etch, or deposit on the surfaces of solids, including 2D planes and 3D nanostructures. An understanding of surface chemistry can be used to optimize existing materials used in microelectronics, catalysis, or solar energy conversion and develop new materials with unique properties. The primary research goals are learning how chemical reactions take place on surfaces and how the atom or molecular group terminating a surface affects the types of structures that can be built on it or using it as a building block. Understanding the reaction mechanism provides a means to rationally design interfaces for specific purposes. Current research projects include 1) engineering the surfaces of semiconductors (GaAs, InAs, InGaAs, CuInS2) for advanced electronic, optoelectronic, and solar devices, 2) synthesis and self-assembly of nanoparticles such as quantum dots (clusters of atoms 1-5 nm in diameter), 3) self-assembled monolayer (SAM) formation, and 4) dealloying metal alloys using liquids and supercritical fluids to make nanoporous noble metal films and composites. We approach these problems by using experiments and modeling to understand the mechanisms of the surface chemical reactions that are at the heart of these technologies.

Publications

Deng, Z., Lie, F. L., Shen, S., Ghosh, I., Mansuripur, M., & Muscat, A. J. (2010). Water-Based Route to Ligand-Selective Synthesis of ZnSe and Cd-Doped ZnSe Quantum Dots with Tunable Ultraviolet A to Blue Photoluminescence. LANGMUIR, 25(1), 434-442.
BIO5 Collaborators
Indraneel Ghosh, Anthony J Muscat
Montaño-Miranda, G., & Muscat, A. (2008). Etching of silicon dioxide with gas phase HF and water: Initiation, bulk etching, and termination. Diffusion and Defect Data Pt.B: Solid State Phenomena, 134, 3-6.
Contreras, Y., & Muscat, A. J. (2015). Chemical Passivation of In0. 53Ga0. 47As (100) Using Ammonium Sulfide and Thiols. ECS Transactions, 69, 261--267.
Xie, B., & Muscat, A. J. (2004). Repair of porous methylsilsesquioxane films using supercritical carbon dioxide. Materials Research Society Symposium Proceedings, 812, 13-18.

Abstract:

Porous methylsilsesquioxane (p-MSQ) films (JSR LKD 5109) were treated with alkyldimethylmonochlorosilanes having chain lengths of one, four, and eight carbon atoms dissolved in supercritical carbon dioxide at 150-300 atm and 50-60°C to repair oxygen ashing damage. Fourier transform infrared (FTIR) spectroscopy showed that trimethylchlorosilane (TMCS), butyldimethylchlorosilane (BDMCS), and octyldimethylchlorosilane (ODMCS) reacted with silanol groups on the surfaces of the pores producing covalent Si-O-Si bonds. Self-condensation between alkylsilanols produced a residue on the surface, which was partially removed using a pure scCO2 rinse. The hydrophobicity of the blanket p-MSQ surface was recovered after silylation treatment as shown by contact angles >85°. The initial dielectric constant of 2.4 ± 0.1 increased to 3.5 ± 0.1 after oxygen plasma ashing and was reduced to 2.6 ± 0.1 by TMCS, 2.8 ± 0.1 by BDMCS, and 3.2 by ODMCS.

Xie, B., & Muscat, A. J. (2003). Water removal and repair of porous ultra low-k films using supercritical CO 2. Proceedings - Electrochemical Society, 26, 279-288.

Abstract:

Fourier transform infrared (FTIR) spectroscopy was used to investigate the effect of adding cosolvents (aliphatic C1 to C6 alcohols) and Si-bearing precursors hexamethyldisilazane (HMDS) and trimethylchlorosilane (TMCS) to supercritical carbon dioxide (scCO 2) to dry and repair ashed blanket porous ultra low-k (ULK) methyl silsesquioxane (MSQ) films (JSR LKD5109) (k = 2.4). The drying results showed that all of the aliphatic C1-C6 alcohols removed hydrogen-bonded water. The film repair results indicated that HMDS and TMCS reacted with both lone (SiO-H) and H-bonded silanol (SiO-H) groups. The hydrophobicity of the starting surface before ashing was recovered after HMDS and TMCS treatments as confirmed by contact angle measurements (≥84°). Electrical performance was also restored based on dielectric constant values of 2.4 ± 0.1. HMDS and TMCS treatments are an effective approach to restore the degradation of ULK MSQ films due to plasma ashing.