scholarly journals Taguchi Design of Experiment Enabling the Reduction of Spikes on the Sides of Patterned Thin Films for Tunnel Junction Fabrication

MRS Advances ◽  
2017 ◽  
Vol 2 (52) ◽  
pp. 3025-3030 ◽  
Author(s):  
Pawan Tyagi ◽  
Edward Friebe ◽  
Beachrhell Jacques ◽  
Tobias Goulet ◽  
Stanley Travers ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Tunnel Junction ◽  
Design Of Experiment ◽  
Optimum Combination ◽  
Taguchi Design ◽  
Uv Exposure ◽  
Taguchi Design Of Experiment ◽  
Edge Profile ◽  
Patterned Films

ABSTRACTPhotolithographically patterned thin films often possess unwanted spikes along the side edges. These spikes are a significant issue for the development of spinvalve memory, tunnel junction based molecular devices, and micro-electromechanical systems. Here, we report a very simple, economical, and fast way of creating an optimum photoresist profile for the production of spike-free patterned films. This approach is based on performing a soaking step in the positive-photoresist’s developer solution before the UV exposure. However, the success of this method depends on multiple photolithography factors: photoresist thickness (governed by spin speed), soft baking temperature, soaking time in developer, and exposure time. In this paper, we report our systematic experiments to study the effect of these factors by following the L9 experimental scheme of the Taguchi Design of experiment (TDOE) approach. The L9 experiment scheme effectively accommodated the study of four photolithography factors, each with three levels. After performing photolithography as per L9 TDOE scheme, we sputter deposited 20 nm Tantalum to check the side edge profile of the patterned film by atomic force microscope (AFM). We measured the heights of the spikes along the thin film edges. We utilized spike height as the desired property and chose “smaller the better” criteria for the TDOE analysis. TDOE enabled us to understand the relative importance of the parameters, relationship among the parameters, and impact of the various levels of the parameters on the thin film edge profile. TDOE analysis yielded an optimum combination of levels for the four photolithography factors. The optimum combination of photolithography factors included spin speed 4000 rpm, 100 °C soft baking temperature, 60 sec pre-soaking in the developer solution, and 15 sec UV exposure. We validated the TDOE by AFM and observed spike free patterned films. We also made complete tunnel junction devices by utilizing the optimized photolithography factors for the bottom electrode and obtained excellent tunneling behavior. In summary, this study provides a very simple, economical, and fast photolithography approach for creating optimum photoresist profile for the micro-nano scale devices and electromechanical structures.

scholarly journals Porous Ultra-Thin Films from Photocleavable Block Copolymers: In-Situ Degradation Kinetics Study of Pore Material

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 781 ◽  
Author(s):  
Sedakat Altinpinar ◽  
Wael Ali ◽  
Patrick Schuchardt ◽  
Pinar Yildiz ◽  
Hui Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Polymer Film ◽  
Uv Exposure ◽  
Significant Information ◽  
X Ray ◽  
Washing Process

On the basis of the major application for block copolymers to use them as separation membranes, lithographic mask, and as templates, the preparation of highly oriented nanoporous thin films requires the selective removal of the minor phase from the pores. In the scope of this study, thin film of polystyrene-block-poly(ethylene oxide) block copolymer with a photocleavable junction groups based on ortho-nitrobenzylester (ONB) (PS-hν-PEO) was papered via the spin coating technique followed by solvent annealing to obtain highly-ordered cylindrical domains. The polymer blocks are cleaved by means of a mild UV exposure and then the pore material is washed out of the polymer film by ultra-pure water resulting in arrays of nanoporous thin films to remove one block. The removal of the PEO materials from the pores was proven using the grazing-incidence small-angle X-ray scattering (GISAXS) technique. The treatment of the polymer film during the washing process was observed in real time after two different UV exposure time (1 and 4 h) in order to draw conclusions regarding the dynamics of the removal process. In-situ X-ray reflectivity measurements provide statistically significant information about the change in the layer thickness as well as the roughness and electron density of the polymer film during pore formation. 4 H UV exposure was found to be more efficient for PEO cleavage. By in-situ SFM measurements, the structure of the ultra-thin block copolymer films was also analysed and, thus, the kinetics of the washing process was elaborated. The results from both measurements confirmed that the washing procedure induces irreversible change in morphology to the surface of the thin film.

scholarly journals Surface and Morphological Investigation of Synthesized Nanostructured Ridges from Electrospun Polyvinyl Alcohol-Albumin Blend—A Taguchi Design of Experiment Approach

Fibers ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 29
Author(s):  
Jopeth Ramis ◽  
Bryan Pajarito ◽  
Crisneil Natividad ◽  
Mark Jared Van Ocampo ◽  
Crizaldy Tugade ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Flow Rate ◽  
Design Of Experiment ◽  
Surface Characterization ◽  
Taguchi Design ◽  
Root Mean Square Roughness ◽  
Solution Flow Rate ◽  
Radius Of Curvature ◽  
Solution Flow ◽  
Taguchi Design Of Experiment

We report the synthesis of presumably a “nanoridge” from the electrospinning of a hydrophilic polymer–protein blend. The material exhibits vertical elevation from the substrate, distinct from the morphologies seen in electrospinning. It is hypothesized that the formation of the nanostructured ridges is due to the migration of the charged protein to the apex through a highly polarized electric field in electrospinning conditions. In this study, we assessed the polyvinyl alcohol–egg albumin (PVA–EA) system in a solvent comprising of water, formic and acetic acid, together with the tip-to-collector distance (TCD) and solution flowrate. To quantify the factor effects in the surface properties of the material, a Taguchi design of experiment was used. The ridge heights observed ranged from 84.8–639.9 nm, and the material height is predominantly affected by the PVA–EA ratio and solution flow rate. The root mean square roughness was influenced by the TCD and flow rate, which has values ranging from 11.37–57.56 nm. In evaluating the sharpness of the ridge, we used the radius of curvature, where the TCD highly affects the apex sharpness. The work offers not just a likely new class of morphology, but a new perspective on the surface characterization of an electrospun material which could affect the performance of such a use in biological and physical systems.

Optimization of Injection Molding Process Parameters Based on Taguchi Design of Experiment

2012 ◽  
Vol 233 ◽  
pp. 335-338
Author(s):  
Xue Feng Li ◽  
Hong Bin Liu
Keyword(s):  
Design Of Experiment ◽  
Optimization Design ◽  
Mold Temperature ◽  
Taguchi Design ◽  
Injection Molding Process ◽  
Molding Process ◽  
Melt Temperature ◽  
Taguchi Design Of Experiment ◽  
Filling Time ◽  
Warpage Deformation

In this paper, circulating box cover is taken as the main object of the study with the application of Taguchi design of experiment and Moldflow software. The warpage deformation was obtained under different molding conditions including melt temperature, mold temperature, filling time and packing time. The influencing degree and trend of these parameters was studied by using the rang analysis, and the optimization set of factors was obtained. Experimental results show that the optimization design is effective and the warpage of the product reduce.

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