scholarly journals Effect of the Thickness of Insulator Polymeric Films on the Memory Behavior: The Case of the Polymethylmethacrylate and the Polystyrene

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
J. A. Avila-Niño ◽  
A. O. Sustaita ◽  
M. Reyes-Reyes ◽  
R. López-Sandoval
Keyword(s):  
Film Thickness ◽  
Differential Resistance ◽  
Polymeric Films ◽  
Thickness Variation ◽  
Pmma Film ◽  
Organic Layer ◽  
Organic Film ◽  
Aluminum Particles ◽  
Conductivity Switching ◽  
Type Of Behavior

The effect of thickness variation on the memory behavior of the polymethylmethacrylate-(PMMA)-based devices has been investigated. The PMMA film thicknesses have been varied between 5 to 300 nm, and we have found that the film thickness determines the type of behavior: ohmic, write-once-read-many-times (WORM) memory with two ON states, WORM memory with a negative differential resistance (NDR) region, and WORM memory without NDR region. The fact that similar results were obtained using different solvents to dilute PMMA (chlorobenzene, chloroform, and dimethyl sulfoxide), as well as using an other insulating polymer such as polystyrene (PS), leads to the conclusion that the phenomenon of memory depends on the aluminum electrodes, organic film thickness, and the compliance current used during the electroformation whereas the type of organic layer (PMMA or PS) has minor influence. From here, we conclude that the conductivity switching of the insulator organic film is due to the injection of aluminum particles into the film during the first voltage cycle.

Rubber-Assisted Hot Embossing for Structuring Thin Polymer Film Polymeric Films

2006 ◽  
Author(s):  
Pratapkumar Nagarajan ◽  
Donggang Yao
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Polymer Film ◽  
Hot Embossing ◽  
Polymeric Films ◽  
Thin Polymer Film ◽  
Thin Polymer Films ◽  
Process Variables ◽  
Hard Materials ◽  
Thin Polymer

Precision structured polymer thin films with microstructures comparable to or greater than the film thickness are highly desired in many applications. Such micro-patterned thin films, however, are difficult to fabricate using the standard hot embossing technology where both halves of the mold are made of hard materials. This study investigated a rubber-assisted embossing process for structuring thin polymer films. The advantages of the rubber backup instead of a hard support include but are not limited to 1) simplifying the embossing tool, 2) protecting the embossing master, 3) facilitating embossing pressure buildup, and 4) accommodating conformal forming of microscale shell patterns. Several design and process variables including rubber hardness, embossing temperature, embossing pressure and holding time were carefully studied. Thin polystyrene films in a thickness of 25 μm were accurately patterned with microgrooves of characteristic dimensions on the order of 100 μm.

Application of dynamic mesh technology in the oil film flow simulation for hydrostatic bearing

2019 ◽  
Vol 71 (1) ◽  
pp. 146-153
Author(s):  
Yanqin Zhang ◽  
Zhiquan Zhang ◽  
Xiangbin Kong ◽  
Rui Li ◽  
Hui Jiang
Keyword(s):  
Film Thickness ◽  
Flow Velocity ◽  
Manufacturing Industry ◽  
Dynamic Mesh ◽  
Lubricating Oil ◽  
Thickness Variation ◽  
Content Type ◽  
Oil Film ◽  
Rotating Speed ◽  
Hydrostatic Bearing

Purpose The purpose of this paper was to obtain the lubrication characteristics of heavy hydrostatic bearing in heavy equipment manufacturing industry through theoretical analysis and numerical simulation. Design/methodology/approach This paper discusses the influence of oil film thickness variation on velocity field, outlet-L and outlet-R flow velocity under the hydrostatic bearing running in no-load 0 N, load 400 KN, full load 1,500 KN and rotating speeds of 10 r/min, 20 r/min, 30 r/min, 40 r/min, 50 r/min and 60 r/min, by using dynamic mesh technology and FLUENT software. Findings When the working table rotates clockwise, in the change process of oil film thickness, the fluid flow pattern of the lubricating oil at the edge of the sealing oil is the rule of laminar flow, and the oil cavity has a vortex. The outlet-R flow velocity becomes higher and higher by increasing the bearing load and working table speed, and the flow velocity increases with the decrease in oil film thickness; the outlet-L flow velocity increases with the decrease in oil film thickness under low rotating speed (less than 10 r/min) condition and decreases with the decrease of oil film thickness under high rotating speed (more than 60 r/min) condition. Originality/value The influence of the oil film thickness on the flow state distribution of the oil film was analyzed under different working conditions, and the influence rules of oil film thickness on the flow velocity of hydrostatic bearing oil pad was obtained by using dynamic mesh technology.

scholarly journals Polarization Holography in 3-Indoly-Benzylfulgimide/PMMA Film

2011 ◽  
Vol 2011 ◽  
pp. 1-20 ◽  
Author(s):  
Neimule Menke ◽  
Baoli Yao ◽  
Yingli Wang ◽  
Yi Chen
Keyword(s):  
Polarization State ◽  
Polymeric Films ◽  
Holographic Recording ◽  
Orthogonal Polarization ◽  
Pmma Film ◽  
Holographic Storage ◽  
Polarization Holography ◽  
Photochromic Compounds ◽  
Storage Media ◽  
Properties Of Materials

The photochromic and photoanisotropic properties of materials can be used in ordinary and polarization holographic recording respectively. Fulgides are well known as thermally irreversible organic photochromic compounds. And it is found that there exists photoinduced anisotropy in fulgide-doped polymeric films. In this report, a 3-indoly-benzylfulgimide/PMMA film was studied as a holographic storage media. First, the spectra and dynamics of photochromic and photoanisotropic properties of the sample are measured or calculated. Second, the diffraction efficiency (DE) dynamics at 633 nm of four kinds of different polarization holograms recorded in this sample are measured. The maximum DE value about 1% was gotten. Third, the DE spectra and DE dynamics are theoretically calculated in detail, and a good correlation of theoretically derived DE dynamic curves and the measured experimental curves was found. From the DE spectra, it is known that at the wavelengths less than 450 nm or greater than 700 nm, the nondestructive reading can be realized. The DWPS obtained in the experiments are same with the theortically deduced ones, which shows that in the orthogonal polarization holography, the polarization state of the diffracted light is orthogonal to that of the reconstruction light, which is very important to increase the SNR of the holographic storage. And all these results are applied and proved to be correct in high-density holographic image storage experiment. The area density of 2×108 bits/cm2 was obtained, and the encoded data was retrieved without error.

Effect of Stiff Coatings on EHL Film Thickness in Point Contacts

2007 ◽  
Author(s):  
Yuchuan Liu ◽  
Q. Jane Wang ◽  
Dong Zhu
Keyword(s):  
Film Thickness ◽  
Working Conditions ◽  
Coating Thickness ◽  
Point Contact ◽  
Thickness Variation ◽  
Point Contacts ◽  
Lubricant Film Thickness ◽  
Wide Range ◽  
Minimum Film Thickness ◽  
Coating Material Properties

This study investigates the influences of coating material properties and coating thickness on lubricant film thickness based on a point-contact isothermal EHL model developed recently by the authors. The results present the trend of minimum film thickness variation as a function of coating thickness and elastic modulus under a wide range of working conditions. Numerical results indicates that the increase in minimum film thickness, Imax, and the corresponding optimal dimensionless coating thickness, H2, can be expressed in the following formulas: Imax=0.766M0.0248R20.0296L0.1379exp(−0.0245ln2L)H2=0.049M0.4557R2−0.1722L0.7611exp(−0.0504ln2M−0.0921ln2L) These formulas can be used to estimate the effect of a coating on EHL film thickness.

Wafer Nanotopography Effects on CMP: Experimental Validation of Modeling Methods

2001 ◽  
Vol 671 ◽  
Author(s):  
Brian Lee ◽  
Duane S. Boning ◽  
Winthrop Baylies ◽  
Noel Poduje ◽  
Pat Hester ◽  
...  
Keyword(s):  
Film Thickness ◽  
Measurement Data ◽  
Relative Length ◽  
Experimental Results ◽  
Thickness Variation ◽  
Length Scale ◽  
Modeling Approaches ◽  
Measurement Analysis ◽  
Thickness Variations ◽  
Film Thinning

ABSTRACTNanotopography refers to 10-100 nm surface height variations that exist on a lateral millimeter length scale on unpatterned silicon wafers. Chemical mechanical polishing (CMP) of deposited or grown films (e.g., oxide or nitride) on such wafers can generate undesirable film thinning which can be of substantial concern in shallow trench isolation (STI) manufacturability. Proper simulation of the effect of nanotopography on post-CMP film thickness is needed to help in the measurement, analysis, diagnosis, and correction of potential problems.Our previous work has focused on modeling approaches that seek to capture the thinning and post-CMP film thickness variation that results from nanotopography, using different modeling approaches. The importance of relative length scale of the CMP process used (planarization length) to the length scale of the nanotopography on the wafer (nanotopography length) has been suggested.In this work, we report on extensive experiments using sets of 200 mm epi wafers with a variety of nanotopography signatures (i.e., different nanotopography lengths), and CMP processes of various planarization lengths. Experimental results indicate a clear relationship between the relative scales of planarization length and nanotopography length: when the planarization length is less than the nanotopography length, little thinning occurs; when the CMP process has a larger planarization length, surface height variations are transferred into thin film thickness variations. In addition to presenting these experimental results, modeling of the nanotopography effect on dielectric CMP processes is reviewed, and measurement data from the experiments are compared to model predictions. Results show a good correlation between the model prediction and the experimental data.

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