Adhesion testing of atomic layer deposited TiO2 on glass substrate by the use of embedded SiO2 microspheres

Lyytinen, Jussi; Berdova, Maria; Franssila, Sami; Koskinen, Jari

doi:10.1116/1.4827197

Cited by 7 publications

(4 citation statements)

References 12 publications

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“…Mechanical studies on ALD films mostly concentrated on elastic modulus, hardness measurement, or residual stress and can be classified into work on single compound film materials, mainly oxides and nitrides, prepared on stiff substrates, like Si or glass [15,16,17,18,19,20,21,22,23,24,25,26] and Al 2 O 3 [27]. The mechanical properties of nanolaminates films have also been investigated on stiff substrates [19,28,29,30,31,32,33,34].…”

Section: Introductionmentioning

confidence: 99%

Fracture Mechanics and Oxygen Gas Barrier Properties of Al2O3/ZnO Nanolaminates on PET Deposited by Atomic Layer Deposition

et al. 2019

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Rapid progress in the performance of organic devices has increased the demand for advances in the technology of thin-film permeation barriers and understanding the failure mechanisms of these material systems. Herein, we report the extensive study of mechanical and gas barrier properties of Al2O3/ZnO nanolaminate films prepared on organic substrates by atomic layer deposition (ALD). Nanolaminates of Al2O3/ZnO and single compound films of around 250 nm thickness were deposited on polyethylene terephthalate (PET) foils by ALD at 90 °C using trimethylaluminium (TMA) and diethylzinc (DEZ) as precursors and H2O as the co-reactant. STEM analysis of the nanolaminate structure revealed that steady-state film growth on PET is achieved after about 60 ALD cycles. Uniaxial tensile strain experiments revealed superior fracture and adhesive properties of single ZnO films versus the single Al2O3 film, as well as versus their nanolaminates. The superior mechanical performance of ZnO was linked to the absence of a roughly 500 to 900 nm thick sub-surface growth observed for single Al2O3 films as well as for the nanolaminates starting with an Al2O3 initial layer on PET. In contrast, the gas permeability of the nanolaminate coatings on PET was measured to be 9.4 × 10−3 O2 cm3 m−2 day−1. This is an order of magnitude less than their constituting single oxides, which opens prospects for their applications as gas barrier layers for organic electronics and food and drug packaging industries. Direct interdependency between the gas barrier and the mechanical properties was not established enabling independent tailoring of these properties for mechanically rigid and impermeable thin film coatings.

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Section: Introductionmentioning

confidence: 99%

Fracture Mechanics and Oxygen Gas Barrier Properties of Al2O3/ZnO Nanolaminates on PET Deposited by Atomic Layer Deposition

et al. 2019

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“…The lack of other oxides that strongly adhere to TiO 2 , such as Al 2 O 3 , which are present in borosilicate glass slides, might also facilitate the transfer. 62,63 Additionally, we used a lubricant layer to demonstrate the importance of reducing the interaction between TiO 2 NPs and their support to ease the transfer. Specifically, we coated the silicon wafers prior to the deposition of the loaded micelles with a carbon layer (<10 nm).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Synthesis of Binary Nanopatterns on Hydrogels for Initiating Cellular Responses

et al. 2016

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We describe the synthesis of binary nanostructures consisting of PEG hydrogels decorated with arrays of AuNPs and TiO2NPs, and their orthogonal functionalization with various peptides. These ligands are able to promote or elude cell adhesion through integrins, a family of transmembrane receptors that connect cells with the extracellular matrix (ECM) or other cells. The different cell adhesion behaviors observed depending on the peptides used, proved the functionality of such binary nanopatterns, which we expect to find applications not only in tissue engineering but also in smart cell culture systems and biosensors.

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“…Other MEMS based techniques for characterizing the adhesion of thin films have been developed. These techniques include a MEMS shaft-loading blister testing system [41], embedding SiO 2 microspheres in thin films and calculating the critical stress required for detaching the microspheres [42], a magnetically actuated peel test system for thin films [43] and using the deflection of micro-cantilevers to evaluate interface fracture properties [44]. These MEMS based techniques are destructive techniques that require extensive sample preparation time, external systems for load application such as using a nanoindenter system or Atomic Force Microscope and characterization techniques to assess the damaged thin film structure.…”

Section: Introductionmentioning

confidence: 99%

Evaluating the adhesion of SU-8 thin films using an AlN/Si surface acoustic wave sensor

Gowini

Moussa

2015

J. Micromech. Microeng.

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A new approach is developed for evaluating the adhesion of SU-8 thin films using a surface acoustic wave (SAW) sensor. The SAW sensor consists of a silicon (Si) substrate coated with a thin aluminum nitride (AlN) film and two sets of inter-digital electrodes (IDT) patterned on the AlN surface. Two sensor configurations are developed in order to evaluate the adhesion of SU-8. In the first configuration the SU-8 layer is patterned on top of a gold film that is deposited on the AlN surface. In the second configuration the gold film is coated with an omnicoat layer prior to patterning the SU-8 film. Omnicoat is an adhesion promoter for SU-8, which is used to increase its adhesion to gold. The frequency responses from both configurations are measured and the shift in the center frequency value is evaluated. The results illustrate that without omnicoat the center frequency shifts to a higher value indicating an increase in the wave velocity. This is because the poor adhesion of the SU-8 layer without omnicoat causes the wave to be more concentrated in the AlN/Si structure and AlN has a higher acoustic wave velocity in comparison to the SU-8 layer. In addition, four SAW sensors operating at four different center frequencies are developed to investigate the change in sensor sensitivity with the increase in center frequency. The results indicate that the sensor sensitivity increases proportionally to the increase in operating frequency. Finally, a theoretical model is developed to calculate the wave dispersion profile for the SU-8/AlN/Si configuration. The interface of the SU-8/AlN layers is modeled as a layer of mass-less springs with stiffness K(N m−3). The shifts in the wave dispersion profile at different levels of interface spring stiffness are compared to the experimental values to evaluate the adhesion of the SU-8 layer.

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Adhesion testing of atomic layer deposited TiO2 on glass substrate by the use of embedded SiO2 microspheres

Cited by 7 publications

References 12 publications

Fracture Mechanics and Oxygen Gas Barrier Properties of Al2O3/ZnO Nanolaminates on PET Deposited by Atomic Layer Deposition

Fracture Mechanics and Oxygen Gas Barrier Properties of Al2O3/ZnO Nanolaminates on PET Deposited by Atomic Layer Deposition

Synthesis of Binary Nanopatterns on Hydrogels for Initiating Cellular Responses

Evaluating the adhesion of SU-8 thin films using an AlN/Si surface acoustic wave sensor

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