scholarly journals Thermal Induced Microstructures of KOH Etched Silicon Surface

1970 ◽  
Vol 5 (1) ◽  
pp. 62-70 ◽  
Author(s):  
Shobha Kanta Lamichhane
Keyword(s):  
Activation Energy ◽  
Silicon Surface ◽  
Etch Rate ◽  
Low Voltage ◽  
Micro Electro Mechanical System ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Engineering And Technology ◽  
Etched Silicon

Anisotropic KOH etching of silicon for the fabrication of Micro-electro mechanical system (MEMS) part is based on surface finish and angular dependence of etch rate, creating thin diaphragm. The absolute values of orientation dependent etch rate is found to vary with thermal agitation. In this work, experimental results of etch rate is found quite consistent with simulated and are justify with their unusual values of activation energy along different planes. The various sites that an atom can occupy are not equivalent of their energy; some are more favorable to removal than others. In this paper attention is given to demonstrate thermal activation energy is the prime parameter that influences the behavior of etching mechanism as well as AFM surface morphology. Low-voltage contact mode atomic force microscopy (AFM) has been employed to analyze the morphology of the etched silicon surface at relevant different temperature. A systematic variation in morphological growth leads to stabilized surface structure under the influence of associated activation energy is concluded. Key words: Etching; Anisotropy; Etch rate; diaphragm; MEMS; LPCVD; SOI; AFM DOI: 10.3126/kuset.v5i1.2847 Kathmandu University Journal of Science, Engineering and Technology Vol.5, No.1, January 2009, pp 62-70

scholarly journals Thermal Induced Conductance of KOH Etched Silicon Surface

1970 ◽  
Vol 6 (1) ◽  
pp. 79-88
Author(s):  
Shobha Kanta Lamichhane
Keyword(s):  
Silicon Surface ◽  
Etch Rate ◽  
Thermal Activation ◽  
Energy Gap ◽  
Low Voltage ◽  
Thermal Agitation ◽  
Force Microscopy ◽  
Etching Mechanism ◽  
Engineering And Technology ◽  
Etched Silicon

Anisotropic KOH etch rate of silicon is found to vary with thermal agitation along withcrystal plane orientation. In this work, experimental results of etch rate is found with theirunusual values of activation energy along different planes. The various sites that an atomcan occupy are not equivalent of their energy; some are more favorable to removal thanothers. In this paper attention is given to demonstrate thermal activation influences thebehavior of etching mechanism as well as surface morphology. Low-voltage contact modeatomic force microscopy (AFM) has been employed to analyze the morphology of theetched silicon surface at relevant temperature. With temperature evolution the width of theforbidden energy gap is going down and hence conductivity is rises.Keywords: Anisotropy; Etch rate; MEMS; SOI; AFM; Contact mode.DOI: 10.3126/kuset.v6i1.3314 Kathmandu University Journal of Science, Engineering and Technology Vol.6(1) 2010, pp79-88

scholarly journals Thermal Activation of Crystalline Silicon Ions in Alkaline Solution

1970 ◽  
Vol 7 (7) ◽  
pp. 15-18
Author(s):  
Shobha Kanta Lamichhane
Keyword(s):  
Activation Energy ◽  
Etch Rate ◽  
Thermal Activation ◽  
Crystalline Silicon ◽  
Micro Electro Mechanical System ◽  
Alkaline Solutions ◽  
Force Microscopy ◽  
Microstructure Fabrication ◽  
Atomic Force ◽  
Key Techniques

Anisotropic wet chemical etching of silicon in alkaline solutions (KOH) is one of the key techniques for the manufacture of microstructure. Fabrication of Micro-electro mechanical system (MEMS) part demand smooth surface finish and angular dependent etch rate. The absolute values of orientation dependent etch rate is found to vary with thermal agitation. In this work, experimental results of etch rate is found with their unusual values of activation energy along different planes. The various sites that an atom can occupy are not equivalent of their energy; some are more favorable to removal than others. In this paper attention is being given to demonstrate thermal activation is the prime factor that influences the behavior of etching mechanism as well as surface morphology. Atomic force microscopy (AFM) has been employed to analyze the morphology of the etched silicon surface at relevant elevated temperature. A systematic variation in morphological growth leads to stabilized surface structure under the influence of associated activation energy. Keywords: Activation energy; Etching; Anisotropy; Etch rate; MEMS; LPCVD; SOI. DOI: 10.3126/sw.v7i7.3817 Scientific World Vol.7(7) 2009 pp.15-18

High-resolution imaging of biotite dissolution and measurement of activation energy

2008 ◽  
Vol 72 (1) ◽  
pp. 115-120 ◽  
Author(s):  
T. J. McMaster ◽  
M. M. Smits ◽  
S. J. Haward ◽  
J. R. Leake ◽  
S. Banwart ◽  
...  
Keyword(s):  
Activation Energy ◽  
Data Sets ◽  
Ambient Conditions ◽  
Contact Mode ◽  
Force Microscopy ◽  
Etch Pit ◽  
Pit Formation ◽  
Atomic Force ◽  
Diffusion Controlled ◽  
Liquid Cell

AbstractWe have used a direct imaging technique, in situ atomic force microscopy(AFM) to observe the earliest stages of the dissolution of a biotite surface byoxalic acid at temperatures close to ambient conditions, using a speciallydesigned AFM liquid cell and non-invasive intermittent contact mode of operation. From the nm-resolution data sets in x, yand z dimensions, we have measured dissolution rates and determined activation energies for the process as a function of temperature, via a mass-loss calculation. The value of Ea obtained, 49±2 kJ mol-1, appears to be too high to indicate a diffusion-controlled process and is more in line with expectations based on a process limited by the rate of ligand-induced metal cation detachment from the (001) surface. This is consistent with visual observations of the relative rates of etch-pit formation and growth, and accepted knowledge of the biotite crystal structure. Separate calculations based on planar area etch-pit growth, and measurements of etch-pit perimeters confirm this result, and also indicate substantiallyhigher activation energy, up to 80 kJ mol-1, when the edge pits are in an incipient stage.

Surface roughness measurements of vanadium-contaminated fluidized cracking catalysts by atomic force microscopy

1996 ◽  
Vol 54 ◽  
pp. 866-867
Author(s):  
H. Kinney ◽  
M.L. Occelli ◽  
S.A.C. Gould
Keyword(s):  
Surface Roughness ◽  
Zeolite Y ◽  
Atomic Level ◽  
Microporous Structure ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Roughness Measurements ◽  
Cracking Catalysts

For this study we have used a contact mode atomic force microscope (AFM) to study to topography of fluidized cracking catalysts (FCC), before and after contamination with 5% vanadium. We selected the AFM because of its ability to well characterize the surface roughness of materials down to the atomic level. It is believed that the cracking in the FCCs occurs mainly on the catalysts top 10-15 μm suggesting that the surface corrugation could play a key role in the FCCs microactivity properties. To test this hypothesis, we chose vanadium as a contaminate because this metal is capable of irreversibly destroying the FCC crystallinity as well as it microporous structure. In addition, we wanted to examine the extent to which steaming affects the vanadium contaminated FCC. Using the AFM, we measured the surface roughness of FCCs, before and after contamination and after steaming.We obtained our FCC (GRZ-1) from Davison. The FCC is generated so that it contains and estimated 35% rare earth exchaged zeolite Y, 50% kaolin and 15% binder.

scholarly journals Dynamic friction energy dissipation and enhanced contrast in high frequency bimodal atomic force microscopy

Friction ◽  
2021 ◽  
Author(s):  
Xinfeng Tan ◽  
Dan Guo ◽  
Jianbin Luo
Keyword(s):  
Atomic Force Microscopy ◽  
Energy Dissipation ◽  
Contact Friction ◽  
Measuring Instruments ◽  
Dynamic Friction ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Friction Energy ◽  
New Applications

AbstractDynamic friction occurs not only between two contact objects sliding against each other, but also between two relative sliding surfaces several nanometres apart. Many emerging micro- and nano-mechanical systems that promise new applications in sensors or information technology may suffer or benefit from noncontact friction. Herein we demonstrate the distance-dependent friction energy dissipation between the tip and the heterogeneous polymers by the bimodal atomic force microscopy (AFM) method driving the second order flexural and the first order torsional vibration simultaneously. The pull-in problem caused by the attractive force is avoided, and the friction dissipation can be imaged near the surface. The friction dissipation coefficient concept is proposed and three different contact states are determined from phase and energy dissipation curves. Image contrast is enhanced in the intermediate setpoint region. The work offers an effective method for directly detecting the friction dissipation and high resolution images, which overcomes the disadvantages of existing methods such as contact mode AFM or other contact friction and wear measuring instruments.

scholarly journals Atomic force microscopy comparative analysis of the surface roughness of two posterior chamber phakic intraocular lens models: ICL versus IPCL

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Juan Gros-Otero ◽  
Samira Ketabi ◽  
Rafael Cañones-Zafra ◽  
Montserrat Garcia-Gonzalez ◽  
Cesar Villa-Collar ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Intraocular Lenses ◽  
Posterior Chamber ◽  
Anterior Surface ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Phakic Intraocular Lenses ◽  
Roughness Measurements

Abstract Background To compare the anterior surface roughness of two commercially available posterior chamber phakic intraocular lenses (IOLs) using atomic force microscopy (AFM). Methods Four phakic IOLs were used for this prospective, experimental study: two Visian ICL EVO+ V5 lenses and two iPCL 2.0 lenses. All of them were brand new, were not previously implanted in humans, were monofocal and had a dioptric power of − 12 diopters (D). The anterior surface roughness was assessed using a JPK NanoWizard II® atomic force microscope in contact mode immersed in liquid. Olympus OMCL-RC800PSA commercial silicon nitride cantilever tips were used. Anterior surface roughness measurements were made in 7 areas of 10 × 10 μm at 512 × 512 point resolution. The roughness was measured using the root-mean-square (RMS) value within the given regions. Results The mean of all anterior surface roughness measurements was 6.09 ± 1.33 nm (nm) in the Visian ICL EVO+ V5 and 3.49 ± 0.41 nm in the iPCL 2.0 (p = 0.001). Conclusion In the current study, we found a statistically significant smoother anterior surface in the iPCL 2.0 phakic intraocular lenses compared with the VISIAN ICL EVO+ V5 lenses when studied with atomic force microscopy.

Contact and non-contact mode imaging by atomic force microscopy

1996 ◽  
Vol 273 (1-2) ◽  
pp. 138-142 ◽  
Author(s):  
Seizo Morita ◽  
Satoru Fujisawa ◽  
Eigo Kishi ◽  
Masahiro Ohta ◽  
Hitoshi Ueyama ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force

Conducting Polymer nanoComposites (CPC): Nanocharacterisation of layer by layer sprayed PMMA-CNT vapour sensors by Atomic force Microscopy in current Sensing Mode (CS-AFM)

2008 ◽  
Vol 1143 ◽  
Author(s):  
Bijandra Kumar ◽  
Mickaël Castro ◽  
Jianbo Lu ◽  
Jean-François Feller
Keyword(s):  
Atomic Force Microscopy ◽  
Spray Deposition ◽  
Dynamic Mode ◽  
Layer By Layer ◽  
Initial State ◽  
Contact Mode ◽  
Current Sensing ◽  
Multi Wall Carbon Nanotubes ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTOrganic vapour sensors based on poly (methylmethacrylate)-multi-wall carbon nanotubes (PMMA-CNT) conductive polymer nanocomposite (CPC) were developed via layer by layer technique by spray deposition. CPC Sensors were exposed to three different classes of solvents (chloroform, methanol and water) and their chemo-electrical properties were followed as a function of CNTcontent in dynamic mode. Detection time was found to be shorter than that necessary for full recovery of initial state. CNT real three dimensional network has been visualized by Atomic force microscopy in a field assisted intermittent contact mode. More interestingly real conductive network system and electrical ability of CPC have been explored by current-sensing atomic force microscopy (CS-AFM). Realistic effect of voltage on electrical conductivity has been found linear.

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