scholarly journals Delamination of polyimide in hydrofluoric acid

2021 ◽  
Vol 61 (6) ◽  
pp. 684-688
Author(s):  
Asaad K. Edaan Al-mashaal ◽  
Rebecca Cheung
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mass Production ◽  
Hydrofluoric Acid ◽  
Polyimide Film ◽  
Wet Etching ◽  
Polyimide Films ◽  
Nanoelectronic Devices ◽  
Flexible Devices ◽  
Time Required

Wet etching is a critical fabrication step for the mass production of micro and nanoelectronic devices. However, when an extremely corrosive acid such as hydrofluoric (HF) acid are used during etching, an undesirable damage might occur if the device includes a material that is not compatible with the acid. Polyimide thin films can serve as sacrificial/structural layers to fabricate freestanding or flexible devices. The importance of polyimide in microelectronics is due to its relatively low stress and compatibility with standard micromachining processes. In this work, a fast delamination process of a 4-μm-thin film of polyimide from a silicon substrate has been demonstrated. The films’ detachment has been performed using a wet-based etchant of HF acid. Specifically, the effect of HF concentration on the delamination time required to detach the polyimide film from the substrate has been investigated. This study is intended to provide the information on the compatibility of using polyimide films with HF, which can help in the design and fabrication of polyimide-based devices.

Mass Production and Film Thickness Control of Meso Porous Silica Thin Films

2020 ◽  
Author(s):  
Makio Tamada ◽  
Yuta Sunami
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Film Thickness ◽  
Mass Production ◽  
Porous Silica ◽  
Production Method ◽  
Liquid Pool ◽  
Speed Ratio ◽  
Roll To Roll ◽  
New Material

Abstract Mesoporous silica (referred to as MPS), which has pores of hexagonal or cubic structure of several nm to several tens of nm on the surface, is attracting attention as a new material. MPS has a very large specific surface area, so it is used as an adsorbent for gas and water vapor, as a moisture absorbent, and as a separating material. Transparent MPS is also expected to be an optical functional material. MPS thin film is expected to be used as a thin film as an application example. Since MPS thin film can be used in various applications, it will be further developed by mass production. Leads to Therefore, in this study, mass production of MPS thin films and controlled the film thickness was studied. Roll-to-roll (referred to as R2R) production method and a micro gravure printing method was adopted as a method of mass production: transporting polypropylene film and coating on it. As a result, the MPS thin film prepared in this study had a pore structure. it was confirmed that the film thickness could be controlled by changing the peripheral speed ratio. It is considered that the size of the liquid pool between the coating rolls changed. The size and arrangement of the pores could be confirmed by FE-SEM observation.

scholarly journals Raman study of flash-lamp annealed aqueous Cu2ZnSnS4 nanocrystals

2019 ◽  
Vol 10 ◽  
pp. 222-227 ◽  
Author(s):  
Yevhenii Havryliuk ◽  
Oleksandr Selyshchev ◽  
Mykhailo Valakh ◽  
Alexandra Raevskaya ◽  
Oleksandr Stroyuk ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Small Molecules ◽  
Mass Production ◽  
Inert Atmosphere ◽  
Flash Lamp ◽  
Flexible Substrates ◽  
Secondary Phases ◽  
Raman Study ◽  
Power Densities

The effect of flash-lamp annealing (FLA) on the re-crystallization of thin films made of colloidal Cu2ZnSnS4 nanocrystals (NCs) is investigated by Raman spectroscopy. Unlike similar previous studies of NCs synthesized at high temperatures in organic solvents, NCs in this work, which have diameters as small as 2–6 nm, were synthesized under environmentally friendly conditions in aqueous solution using small molecules as stabilizers. We establish the range of FLA conditions providing an efficient re-crystallization in the thin film of NCs, while preserving their kesterite structure and improving their crystallinity remarkably. The formation of secondary phases at higher FLA power densities, as well as the dependence of the formation on the film thickness are also investigated. Importantly, no inert atmosphere for the FLA treatment of the NCs is required, which makes this technology even more suitable for mass production, in particular for printed thin films on flexible substrates.

scholarly journals Mechanical Behavior of Spin-Coated Sb2S3 light Absorption Thin Films

2021 ◽  
Vol 59 (1) ◽  
pp. 1-7
Author(s):  
Mao Zhang ◽  
Dayoung Yoo ◽  
Youngseon Jeon ◽  
Dongyun Lee
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Properties ◽  
Light Absorption ◽  
Indentation Test ◽  
Flexible Devices ◽  
Heat Treated ◽  
Coating Method ◽  
Continuous Stiffness Measurement ◽  
Fto Glass

To measure the mechanical properties of Sb2S3, a two-component compound semiconductor used in the light absorption layer of a solar cell, Sb2S3 thin films were formed on FTO glass using the spin coating method. The spin-coated Sb2S3 thin films were heat-treated at 200 <sup>o</sup>C in an Ar atmosphere for up to 1 hour to form a thin film with continuous crystalline structures. A nanoindentation system was used to measure the mechanical properties of the spin-coated Sb2S3 thin films, and the phenomena appearing during indentation were analyzed. We used the continuous stiffness measurement (CSM) technique, and Young's modulus and hardness measured with the indentation depth of 250 nm were about 53.1 GPa and 1.43 GPa, respectively. The results were analyzed and compared with literature values, which varied from 40 GPa for the nanowire forms of Sb2S3 to 117 GPa, based upon simulation results. Since there are few studies on the mechanical properties of spin-coated Sb2S3 thin films, the results of this study are worthwhile. Besides, we observed that the Sb2S3 thin film had a little brittleness in the indentation test at higher load, and the microstructure was pushed around the indenter depending on the degree of bonding to the FTO glass substrate. This is a matter to be considered when making flexible devices in the future.

An Interesting Result of Dielectric Property for Novel Polyimides with Fluorene Groups

2010 ◽  
Vol 663-665 ◽  
pp. 511-514 ◽  
Author(s):  
Yuan Yuan ◽  
Bing Xie ◽  
Yu Wang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Properties ◽  
Dielectric Property ◽  
Dielectric Constants ◽  
The Other ◽  
Polyimide Films ◽  
Low Dielectric ◽  
High Dielectric ◽  
Biphenyltetracarboxylic Dianhydride

A series of polyimide thin films were prepared successfully based on bis[3,5-dimethyl-4- (4-aminophenoxy)phenyl]methane （BDAPM）, 9,9-bis（4-（4-aminophenoxy）phenyl）fluorene (BAOFL) and different dianhydrides. And an interesting result of dielectric property for polyimide thin films was found that the polyimide thin film prepared with 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) exhibited high dielectric constants of 5.7 at 1MHz. Conversely, the other polyimides possessing fluorene groups showed low dielectric constants. The structures and the mechanical properties of polyimide films also proved the reason for results of dielectric properties.

scholarly journals CuO Thin Films Functionalized with Gold Nanoparticles for Conductometric Carbon Dioxide Gas Sensing

Chemosensors ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 56 ◽  
Author(s):  
Robert Wimmer-Teubenbacher ◽  
Florentyna Sosada-Ludwikowska ◽  
Bernat Travieso ◽  
Stefan Defregger ◽  
Oeznur Tokmak ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Carbon Dioxide ◽  
Gold Nanoparticles ◽  
Gas Sensors ◽  
Mass Production ◽  
Gas Sensing ◽  
Cupric Oxide ◽  
Base Material ◽  
Lift Off

Metal oxides (MOx) are a well-established material for gas sensing. MOx-based gas sensors are sensitive to a wide variety of gases. Furthermore, these materials can be applied for the fabrication of low-cost and -power consumption devices in mass production. The market of carbon dioxide (CO 2 ) gas sensors is mainly dominated by infra-red (IR)-based gas sensors. Only a few MOx materials show a sensitivity to CO 2 and so far, none of these materials have been integrated on CMOS platforms suitable for mass production. In this work, we report a cupric oxide (CuO) thin film-based gas sensor functionalized with gold (Au) nanoparticles, which exhibits exceptional sensitivity to CO 2 . The CuO-based gas sensors are fabricated by electron beam lithography, thermal evaporation and lift-off process to form patterned copper (Cu) structures. These structures are thermally oxidized to form a continuous CuO film. Gold nanoparticles are drop-coated on the CuO thin films to enhance their sensitivity towards CO 2 . The CuO thin films fabricated by this method are already sensitive to CO 2 ; however, the functionalization of the CuO film strongly increases the sensitivity of the base material. Compared to the pristine CuO thin film the Au functionalized CuO film shows at equal operation temperatures (300 ∘ C) an increase of sensitivity towards the same gas concentration (e.g., 2000 ppm CO 2 ) by a factor of 13. The process flow used to fabricate Au functionalized CuO gas sensors can be applied on CMOS platforms in specific post processing steps.

Properties Of A Photoimageable Thin Polyimide Film II.

1991 ◽  
Vol 227 ◽  
Author(s):  
Taishih Maw ◽  
Richard E. Hopla
Keyword(s):  
Thin Film ◽  
Weight Loss ◽  
Electrical Properties ◽  
Dissipation Factor ◽  
Polyimide Film ◽  
Decomposition Temperature ◽  
Polyimide Films ◽  
Mechanical And Electrical Properties ◽  
Thermal And Electrical Properties ◽  
Cure Temperature

ABSTRACTThe polylmide synthesized from benzophenonetetracarboxylic dianhydride and alkyl-substituted diamines is inherently photosensitive at ≤365 nm, and a solvent soluble, negative-acting system can be formulated from the fully-imidized resin. The lithographic, thermal, mechanical, and electrical properties of the polyimide films have been characterized. This polyimide film shows good thermal, mechanical, and electrical properties, and a 1:1 aspect ratio is consistently achieved on 10 μm thick films. The thermal properties of the films were determined using TGA and TMA methods. The decomposition temperature was 527°C, the weight loss of the cured film at 350°C in nitrogen was 0.04 %/hour and the thermal expansion coefficient was 37 ppm/°C. The dielectric constant and dissipation factor of the film were 3.0 and 0.003 respectively at 4% humidity. The effects of hard-bake time, hard-bake temperature, nitrogen purge rate during heat treatment, and humidity on the thermal and electrical properties of the thin film were also examined, and are presented here. The rate of weight loss of the cured film increases when the rate of nitrogen purge decreases or when the cure temperature increases. Longer heat treatments resulted in a slight decrease in the CTE and an Increase in the Tg. The electrical properties of the films are dependent both on the humidity during measurement and on the hard-bake temperature.

scholarly journals Selective Wet-Etching of Amorphous/Crystallized Sb-Se Thin Films

2012 ◽  
Vol 49 (2) ◽  
pp. 45-50
Author(s):  
O. Shiman ◽  
V. Gerbreders ◽  
E. Sledevskis ◽  
A. Bulanovs
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Chemical Etching ◽  
Etching Rate ◽  
Wet Etching ◽  
Sample Composition ◽  
Wet Chemical ◽  
Wet Chemical Etching ◽  
Etching Selectivity

Selective Wet-Etching of Amorphous/Crystallized Sb-Se Thin Films The paper is focused on the development of an in situ real-time method for studying the process of wet chemical etching of thin films. The results of studies demonstrate the adequate etching selectivity for all thin film SbxSe100-x (x = 0, 20, 40, 50, 100) compositions under consideration. Different etching rates for the as-deposited and laser exposed areas were found to depend on the sample composition. The highest achieved etching rate was 1.8 nm/s for Sb40Se60 samples.

scholarly journals Solution-processed transparent ferroelectric nylon thin films

2019 ◽  
Vol 5 (8) ◽  
pp. eaav3489 ◽  
Author(s):  
Saleem Anwar ◽  
Daniel Pinkal ◽  
Wojciech Zajaczkowski ◽  
Philipp von Tiedemann ◽  
Hamed Sharifi Dehsari ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Data Storage ◽  
Ferroelectric Thin Film ◽  
Electronic Textiles ◽  
Solution Processed ◽  
Flexible Devices ◽  
Thin Film Capacitors ◽  
Low Temperature Processing ◽  
Engineering Polymers

Ferroelectricity, a bistable ordering of electrical dipoles in a material, is widely used in sensors, actuators, nonlinear optics, and data storage. Traditional ferroelectrics are ceramic based. Ferroelectric polymers are inexpensive lead-free materials that offer unique features such as the freedom of design enabled by chemistry, the facile solution-based low-temperature processing, and mechanical flexibility. Among engineering polymers, odd nylons are ferroelectric. Since the discovery of ferroelectricity in polymers, nearly half a century ago, a solution-processed ferroelectric nylon thin film has not been demonstrated because of the strong tendency of nylon chains to form hydrogen bonds. We show the solution processing of transparent ferroelectric thin film capacitors of odd nylons. The demonstration of ferroelectricity, as well as the way to obtain thin films, makes odd nylons attractive for applications in flexible devices, soft robotics, biomedical devices, and electronic textiles.

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 544-545
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Steady State ◽  
Room Temperature ◽  
Small Mass ◽  
Equilibrium Pressure ◽  
Biological Objects ◽  
Mechanical Pump ◽  
Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

Observations on the growth of YBa2Cu3O7-δ thin films on MgO by pulsed-laser ablation

1991 ◽  
Vol 49 ◽  
pp. 1068-1069
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Laser Ablation ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Laser Ablation Process ◽  
Deposition Parameters

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.

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