Publications

2024

1. PCSI 49

   Multi-Material Deposition for Spatial Atomic Layer Deposition Process

   Atilla Varga, Matthias Carnoy, Ivan Kundrata, and 2 more authors

   49th International Conference on the Physics and Chemistry of Surfaces and Interfaces. Santa Fe, New Mexico., Jan 2024

2023

1. AVS 69

   Recent Advancements for Atomic Layer Advanced Manufacturing Processes: Microreactor Direct Atomic Layer Processing (μDALP™)

   Maksym Plakhotnyuk, Atilla Varga, Ivan Kundrata, and 1 more author

   AVS 69th International Symposium and Exhibition. Protland, USA., Nov 2023
2. ECS 244

   Inherently Selective Atomic Layer Deposition for Optical and Sensor Applications: Microreactor Direct Atomic Layer Processing (μDALP™)

   Maksym Plakhotnyuk, Atilla Varga, Karolis Parfeniukas, and 2 more authors

   244th ECS (The Electrochemical Society) International Meeting. Gothenburg, Sweden., Nov 2023
3. IEEE NMDC 2023

   Multi Cycle and Material Deposition for Spatial Atomic Layer Deposition Process

   Atilla Varga, Matthias Carnoy, Ivan Kundrata, and 2 more authors

   IEEE Nanotechnology Materials and Devices International Conference. Salerno, Italy, Oct 2023
4. IEEE NAP 2023

   Direct Atomic Layer Processing on Complex Surface Morphologies

   Maksym Plakhotnyuk, Atilla Varga, Karolis Parfeniukas, and 2 more authors

   IEEE Nanomaterials: Applications and Properties International Conference. Bratislava, Slovakia., Sep 2023
5. ALD 2023

   Multi Cycle and Material Deposition for Spatial Atomic Layer Deposition Process

   Atilla Varga, Matthias Carnoy, Mette Funding-la-Cour, and 3 more authors

   AVS Atomic Layer Deposition International Conference. Bellevue, USA., Jul 2023
6. ALD 2023

   Recent Advances for Spatial Atomic Layer Deposition Process; Microreactor Direct Atomic Layer Processing (μDALP™)

   Maksym Plakhotnyuk, Atilla Varga, Ivan Kundrata, and 1 more author

   AVS Atomic Layer Deposition International Conference. Bellevue, USA., Jul 2023
7. JVSTA

   Reversible alteration of 3D printed polymer properties via infiltration of alumina by atomic layer deposition

   Atilla Varga, and Seán T. Barry

   Journal of Vacuume Science & Technology A., Feb 2023

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   3D printed acrylonitrile butadiene styrene (ABS) and polyvinyl alcohol (PVA) structures were infiltrated by alumina (Al2O3) using a trimethylaluminum(III) and water ALD process at 130 and 80 °C, respectively, to alter their physical properties. Differential scanning calorimetry was used to determine the glass transition temperature (Tg) of the polymers’ pre- and post-deposition after varying the number of ALD cycles, resulting in a change of ∼9 and ∼ 27 °C for ABS and PVA, respectively. After one heat cycle, the postdeposition Tg reverted back to its predisposition point indicating reversibility of the deposition effects are possible. Optimal growing patterns, polymer composition, and inhibiting surface coatings—seen by energy-dispersive x-ray spectroscopy mapping—affected the amount of infiltration possible within the polymer substrate and, in turn, Tg. The results achieved provide guidelines to altering the physical and thermal properties of 3D printed polymer architectures.

2022

1. M.Sc. Thesis

   Enhancing 3D Printed Substrates Using Atomic Layer Deposition

   Atilla Varga

   Carleton University, Aug 2022

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   3D printed Acrylonitrile Butadiene Styrene (ABS) and Polyvinyl Alcohol (PVA) polymer structures were coated and infiltrated with alumina (Al2O3) using the trimethylaluminum(III) (TMA) and water ALD process. Coating studies on ABS were carried out at 80˚C, which resulted in a 203 nm thin film with a 1.35 Å growth per cycle (GPC). The thin film was a well-adhered protective overcoating which prevented the reaction with acetone vapors in solvent resistance experiments. Infiltration studies on ABS and PVA structures were preformed at 130˚C and 80˚C respectively, to alter their physical properties. Differential Scanning Calorimetry (DSC) was used to determine the Glass Transition Temperature (Tg) of the polymers pre- and post-deposition after varying the number of ALD cycles, resulting in a change of   9˚C and   27˚C for ABS and PVA, respectively. After one heat cycle the post-deposition Tg reverted back to its pre-disposition point indicating reversibility of the deposition effects.

2. ALD 2022

   Modified 3D-Printing Architectures; Effects of Infiltration by Alumina on ABS and PVA

   Atilla Varga, and Seán T. Barry

   AVS Atomic Layer Deposition International Conference. Ghent, Belgium., Jun 2022
3. JVSTA

   Modified 3D-printed architectures; Effects of coating by alumina on acrylonitrile butadiene styrene

   Atilla Varga, and Seán T. Barry

   Journal of Vacuume Science & Technology A., Feb 2022

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   3D-printed acrylonitrile butadiene styrene (ABS) polymer structures were coated with alumina (Al2O3) using the trimethylaluminum(III) and water atomic layer deposition (ALD) process at 80 °C, which resulted in a 203 nm thin film with a 1.35 Å growth per cycle. This thin film was a well-adhered protective overcoating on ABS to prevent reaction with acetone vapors in a solvent resistance experiment. Scratch tests were not able to remove the overcoating from the polymer surface, which provided a 50% and 32% increase in acetone vapor resistance before initial deformation and complete structure collapse, respectively. A more aggressive tape test caused delamination of the protective coating. This proof-of-concept experiment demonstrates how 3D printing combined with ALD overcoating can alter the chemical characteristics of complex polymer architectures.

4. ChemRxiv

   Synthesis, Structure and Thermal Properties of Volatile Group 11 Triazenides as Potential Precursors for Vapor Deposition

   R. Samii, A. Fransson, D. Zanders, and 5 more authors

   ChemRxiv., Feb 2022

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   Group 11 thin films are desirable as interconnects in microelectronics. Although many M–N bonded Cu precursors have been explored for vapor deposition, there is currently a lack of suitable Ag and Au derivatives. Herein, we present monovalent Cu, Ag and Au 1,3-di-tert-butyltriazenides that have potential for use in vapor deposition. These compounds possess thermal stability and volatility that rival that of current state-of-the-art group 11 precursors with bidentate M–N bonded ligands. All compound sublime quantitatively between 120 and 130 °C at 0.5 mbar. Thermogravimetric analysis showed the Cu and Ag compounds both volatilized at  200 °C with 0 and 2% residual mass, respectively. The Au triazenide showed two separated mass loss events at  175 and 240 °C, and 35% residual mass. The crystal structure of the Cu compound showed a dimer, whilst the Ag and Au derivatives were tetrameric. Nuclear magnetic resonance spectroscopy showed dimers for the Cu and Au compounds and a dimer/tetramer equilibrium for the Ag compound. Electronic energies from density functional theory calculations confirmed dimeric preference for the Cu triazenide while Ag and Au preferred the tetrameric. However, all three compounds showed dimeric preference when accounting for entropy. Dimers are, therefore, expected to dominate in the gas phase for all three compounds during sublimation. Natural bond orbital analysis was used to identify orbital interactions important for the dimer/tetramer preference. Three factors were identified, in conjunction with strong metal-metal interactions, to increase the preference for rhombic tetramers.

2021

1. ALD 2021

   Modified 3D-Printing Architectures; Effects of Coating and Infiltration by Alumina on ABS

   Atilla Varga, Brian Nwokolo, Peter Gordon, and 1 more author

   AVS Atomic Layer Deposition International Conference. Virtual Meeting., Jun 2021

2020

1. ALD 2020

   Applying a Figure of Merit to Known and Novel Copper Precursors

   Atilla Varga, Matthew B.E. Griffiths, and Seán T. Barry

   AVS Atomic Layer Deposition International Conference. Virtual Meeting., Jul 2020

2019

1. CCCE 2019

   Designing Thermal Atomic Layer Deposition Processes for Gold Metal Using New Organogold Precursors and Co-reagents

   Matthew B.E. Griffiths, Goran Bačić, Atilla Varga, and 1 more author

   Canadian Chemistry Conference and Exhibition. Quebec City, Canada., Jun 2019