Exploring TMA and H2O Flow Rate Effects on Al2O3 Thin Film Deposition by Thermal ALD: Insights from Zero-Dimensional Modeling Júlia Karnopp, Nilton Azevedo Neto, Thaís Vieira, Mariana Fraga, Argemiro da Silva Sobrinho, et al. Coatings, 2024 This study investigates the impact of vapour-phase precursor flow rates—specifically those of trimethylaluminum (TMA) and deionized water (H2O)—on the deposition of aluminum oxide (Al2O3) thin films through atomic layer deposition (ALD). It explores how these flow rates influence film growth kinetics and surface reactions, which are critical components of the ALD process. The research combines experimental techniques with a zero-dimensional theoretical model, designed specifically to simulate the deposition dynamics. This model integrates factors such as surface reactions and gas partial pressures within the ALD chamber. Experimentally, Al2O3 films were deposited at varied TMA and H2O flow rates, with system conductance guiding these rates across different temperature settings. Film properties were rigorously assessed using optical reflectance methods and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. The experimental findings revealed a pronounced correlation between precursor flow rates and film growth. Specifically, at 150 °C, film thickness reached saturation at a TMA flow rate of 60 sccm, while at 200 °C, thickness peaked and then declined with increasing TMA flow above this rate. Notably, higher temperatures generally resulted in thinner films due to increased desorption rates, whereas higher water flow rates consistently produced thicker films, emphasizing the critical role of water vapour in facilitating surface reactions. This integrative approach not only deepens the understanding of deposition mechanics, particularly highlighting how variations in precursor flow rates distinctly affect the process, but also significantly advances operational parameters for ALD. These insights are invaluable for enhancing the application of ALD technologies across diverse sectors, including microelectronics, photovoltaics, and biomedical coatings, effectively bridging the gap between theoretical predictions and empirical results.
Enhancing Carbon Fiber Fabrics with ALD AlxOy Coatings: An Investigation of Thickness Effects on Weight, Morphology, Coloration, and Thermal Properties Vanessa Dias, Nierlly Galvão, Felipe Miranda, Mariana Fraga, Gilberto Petraconi, et al. Coatings, 2024 This study explores the impact of non-stoichiometric aluminum oxide (AlxOy) coatings applied via thermal atomic layer deposition (ALD) on carbon fiber fabrics (CFFs), emphasizing volume per cycle, FESEM analyses, color transitions, and thermal stability enhancements. Using trimethylaluminum and water at 100 °C, AlxOy was deposited across a range of 1000 to 5000 ALD cycles, with film thicknesses extending up to 500 nm. This notable increase in the volume of material deposited per cycle was observed for the 3D CFFs, highlighting ALD’s capability to coat complex structures effectively. FESEM analyses revealed the morphological evolution of CFF surfaces post-coating, showing a transition from individual grains to a dense, continuous layer as ALD cycles increased. This morphological transformation led to significant color shifts from green to red to blue, attributed to structural coloration effects arising from variations in film thickness and surface morphology. Thermogravimetric analyses (TGA and dTG) indicated that the AlxOy coatings enhanced the thermal stability of CFFs, with a postponement in degradation onset observed in samples subjected to more ALD cycles. In essence, this research highlights the nuanced relationship between ALD processing parameters and their collective influence on both the aesthetic and functional properties of CFFs. This study illustrates ALD’s potential in customizing CFFs for applications requiring specific color and thermal resilience, balancing the discussion between the surface morphological changes and their implications for color and thermal behavior.
Impact of Nb2O5 Coating Produced by Using the Reactive Sputtering Technique on Bacterial Biofilm Formation AMH da Silva, A Baptista, VBS Albuquerque, J de Moraes, CA Fortulan, ... ACS Omega 11 (4), 5883 , 2026 2026
Impact of Nb 2 O 5 Coating Produced by Using the Reactive Sputtering Technique on Bacterial Biofilm Formation AM Hakme da Silva, A Baptista, VBS Albuquerque, J de Moraes, ... ACS Omega , 2026 2026
Introductory Chapter: Silicon MA Fraga Silicon Carbide-From Materials Science to Nanotechnology and … , 2025 2025
Splitting: Advances, Applications RS Pessoa, MA Fraga Silicon Carbide-From Materials Science to Nanotechnology and … , 2025 2025
Introductory Chapter: Silicon Carbide at the Forefront of Materials Innovation and Device Integration MA Fraga Silicon Carbide-From Materials Science to Nanotechnology and Microelectronics , 2025 2025
Silicon Carbide-From Materials Science to Nanotechnology and Microelectronics MA Fraga 2025
SPECIAL EDITION–45 YEARS OF THE REVISTA BRASILEIRA DE APLICAÇÕES DE VÁCUO MA Fraga, DA Duarte, FC da Silva, LS Rossino, JC Sagás Revista Brasileira de Aplicações de Vácuo 44 , 2025 2025
Next-generation nanomaterials for biomedical integration: Synergy, function, and translation RS Pessoa, J Delezuk, B Manzolli, S Saddow, MA Fraga Journal of Materials Research, 1-12 , 2025 2025 Citations: 2
Silicon Carbide in Photoelectrochemical Water Splitting: Advances, Applications, and Future Horizons RS Pessoa, MA Fraga Silicon Carbide-From Materials Science to Nanotechnology and Microelectronics , 2025 2025 Citations: 1
From Silicon to PCB: A Comparative Study of Fabrication Routes and Performance of Capacitive Pressure Sensors MA Fraga, E Bonturim, LAA Santos, ID Marques, M Massi, LA Rasia, ... Sensors & Transducers 270 (3), 11-19 , 2025 2025
Proposal of a Sensor and IoT-Based Structural Health Monitoring System for Marine Fenders LAA Santos, MA Fraga 2025 Symposium on Internet of Things (SIoT), 1-4 , 2025 2025
Capacitive pressure sensors on PCB substrates: comparative study of sputtered Ta and Cr electrodes MA Fraga, E Bonturim, CAM De Oliveira, LA Rasia Proceedings of the 11th International Conference on Sensors and Electronic … , 2025 2025 Citations: 1
Evaluation of a Tantalum Film Capacitive Pressure Sensor on PCB with Arduino-Based Readout MA Fraga, E Bonturim, CAM De Oliveira, LA Rasia, M Massi, H Furlan 2025 39th Symposium on Microelectronics Technology and Devices (SBMicro) 1, 1-3 , 2025 2025 Citations: 1
The role of semiconductor thin films in advancing MEMS sensor technology MA Fraga, RS Pessoa IEEE Sensors Reviews , 2025 2025 Citations: 12
Focus on women’s achievements and perspectives in materials sciences J Wu, M Fraga, P Malar, L Wittaker-Brooks, M Marmiroli, MV Nikolić, ... Materials Research Express 12 (3), 030201 , 2025 2025
Enhancing temperature control in 3D bioprinting: a comprehensive study on PID control strategies AM Hakme da Silva, ES Silva, DSF Magalhães, MA Fraga, ... Journal of Biomedical Nanotechnology 20 (11), 1747-1755 , 2024 2024 Citations: 3
Enhancing Carbon Fiber Fabrics with ALD Al x O y Coatings: An Investigation of Thickness Effects on Weight, Morphology, Coloration, and Thermal Properties V Dias, N Galvão, F Miranda, M Fraga, G Petraconi, H Maciel, R Pessoa Coatings 14 (5), 596 , 2024 2024 Citations: 4
Exploring TMA and H 2 O Flow Rate Effects on Al 2 O 3 Thin Film Deposition by Thermal ALD: Insights from Zero-Dimensional Modeling J Karnopp, NA Neto, T Vieira, M Fraga, AS Sobrinho, J Sagás, R Pessoa Coatings 14 (5), 578 , 2024 2024 Citations: 10
Initial Development of a Low-Cost Assistive Robotic Manipulator Using ESP32 LFG Bittencourt, MA Fraga 2024 IEEE International Conference on Advanced Systems and Emergent … , 2024 2024 Citations: 4
Semiconducting Polymer Materials for Biosensing Applications KY Cheong, MA Fraga, P Sonar, R Pessoa, J Casanova-Moreno Elsevier , 2024 2024 Citations: 3
MOST CITED SCHOLAR PUBLICATIONS
Wide bandgap semiconductor thin films for piezoelectric and piezoresistive MEMS sensors applied at high temperatures: an overview MA Fraga, H Furlan, RS Pessoa, M Massi Microsystem technologies 20 (1), 9-21 , 2014 2014 Citations: 212
Nanostructured thin films based on TiO2 and/or SiC for use in photoelectrochemical cells: A review of the material characteristics, synthesis and recent applications RS Pessoa, MA Fraga, LV Santos, M Massi, HS Maciel Materials Science in Semiconductor Processing 29, 56-68 , 2015 2015 Citations: 120
Progresses in Synthesis and Application of SiC Films: From CVD to ALD and from MEMS to NEMS M Fraga, R Pessoa Micromachines 11 (9), 799 , 2020 2020 Citations: 88
Antimicrobial Effect of Plasma-Activated Tap Water on Staphylococcus aureus , Escherichia coli , and Candida albicans W Chiappim, AG Sampaio, F Miranda, M Fraga, G Petraconi, ... Water 13 (11), 1480 , 2021 2021 Citations: 74
Atomic Layer Deposited TiO 2 and Al 2 O 3 Thin Films as Coatings for Aluminum Food Packaging Application V Dias, H Maciel, M Fraga, AO Lobo, R Pessoa, FR Marciano Materials 12 (4), 682 , 2019 2019 Citations: 66
TiO2 coatings via atomic layer deposition on polyurethane and polydimethylsiloxane substrates: Properties and effects on C. albicans growth and inactivation process RS Pessoa, VP Dos Santos, SB Cardoso, A Doria, FR Figueira, ... Applied Surface Science 422, 73-84 , 2017 2017 Citations: 62
Black TiO 2 Thin Films Production Using Hollow Cathode Hydrogen Plasma Treatment: Synthesis, Material Characteristics and Photocatalytic Activity A Godoy Junior, A Pereira, M Gomes, M Fraga, R Pessoa, D Leite, ... Catalysts 10 (3), 282 , 2020 2020 Citations: 52
Emerging Materials for Energy Conversion and Storage KY Cheong, G Impellizzeri, MA Fraga Elsevier 1, 450 , 2018 2018 Citations: 52
Studies on SiC, DLC and TiO 2 thin films as piezoresistive sensor materials for high temperature application MA Fraga, H Furlan, RS Pessoa, LA Rasia, CFR Mateus Microsystem technologies 18 (7), 1027-1033 , 2012 2012 Citations: 52
The status and perspectives of nanostructured materials and fabrication processes for wearable piezoresistive sensors W Chiappim, MA Fraga, H Furlan, DC Ardiles, RS Pessoa Microsystem Technologies 28 (7), 1561-1580 , 2022 2022 Citations: 51
Relationships among growth mechanism, structure and morphology of PEALD TiO 2 films: the influence of O 2 plasma power, precursor chemistry and plasma … W Chiappim, GE Testoni, A Doria, RS Pessoa, MA Fraga, N Galvão, ... Nanotechnology 27 (30), 305701 , 2016 2016 Citations: 49
Nitrogen doping of SiC thin films deposited by RF magnetron sputtering MA Fraga, M Massi, IC Oliveira, HS Maciel, SG dos Santos Filho, ... Journal of Materials Science: Materials in Electronics 19 (8), 835-840 , 2008 2008 Citations: 48
Influence of the Al 2 O 3 partial-monolayer number on the crystallization mechanism of TiO 2 in ALD TiO 2 /Al 2 O 3 nanolaminates and its impact on the material … GE Testoni, W Chiappim, RS Pessoa, MA Fraga, W Miyakawa, ... Journal of Physics D: Applied Physics 49 (37), 375301 , 2016 2016 Citations: 46
Silicon carbide in microsystem technology—Thin film versus bulk material MA Fraga, M Bosi, M Negri Advanced silicon carbide devices and processing 1, 3-31 , 2015 2015 Citations: 45
Fabrication and characterization of a SiC/SiO2/Si piezoresistive pressure sensor MA Fragaa, H Furlan, M Massia, IC Oliveiraa, LL Koberstein Procedia Engineering 5, 609-612 , 2010 2010 Citations: 35
Nano-and microcrystalline diamond deposition on pretreated WC–Co substrates: structural properties and adhesion MA Fraga, A Contin, LAA Rodríguez, J Vieira, RA Campos, EJ Corat, ... Materials Research Express 3 (2), 025601 , 2016 2016 Citations: 34
Plasma-assisted techniques for growing hard nanostructured coatings: An overview RS Pessoa, MA Fraga, LV Santos, N Galvão, HS Maciel, M Massi Anti-Abrasive Nanocoatings, 455-479 , 2015 2015 Citations: 34
Applications of SiC-based thin films in electronic and MEMS devices MA Fraga, RS Pessoa, M Massi, HS Maciel Physics and technology of silicon carbide devices , 2012 2012 Citations: 32
Effect of nitrogen content in amorphous SiCxNyOz thin films deposited by low temperature reactive magnetron co-sputtering technique HS Medeiros, RS Pessoa, JC Sagás, MA Fraga, LV Santos, HS Maciel, ... Surface and Coatings Technology 206 (7), 1787-1795 , 2011 2011 Citations: 32
Recent developments on silicon carbide thin films for piezoresistive sensors applications MA Fraga, RS Pessoa, HS Maciel, M Massi Silicon Carbide—Materials, Processing and Applications in Electronic … , 2011 2011 Citations: 32
