A novel and reliable approach for controlling silicon membrane thickness with smooth surface

2022 ◽  
Vol 251 ◽  
pp. 111640
Author(s):  
Yijie Li ◽  
Yifang Chen ◽  
Hongchang Wang ◽  
Xujie Tong ◽  
Chengyang Mu ◽  
...  
Keyword(s):  
Smooth Surface ◽  
Membrane Thickness ◽  
Silicon Membrane

Tunable adhesion of an elastic pillar by pressurizing inner cavity

2021 ◽  
pp. 135065012110182
Author(s):  
Turgay Eray
Keyword(s):  
Adhesion Strength ◽  
Smooth Surface ◽  
Adhesive Contact ◽  
Adhesive Force ◽  
Membrane Thickness ◽  
Cavity Pressure ◽  
Flat Punch ◽  
Contact Type ◽  
Inner Pressure ◽  
Rigid Smooth

This work studies the effect of a cavity with inner pressure on the adhesion of circular pillars with a flat tip in contact with a rigid smooth surface. The inner cavity of pillars is pressurized positively before the contact. The effect of the cavity on the adhesion is examined for different cavity diameters and different membrane thicknesses over the cavity. The shape of the tip of the pillars is changed in accordance with the cavity dimension and the positive cavity pressure, which allows the change of an adhesive contact type from a flat-punch adhesive contact to a spherical adhesive contact that results in tunable adhesion strength of circular pillars. The results demonstrate that having an inner cavity reduces the adhesion, where the cavity diameter is more effective than the membrane thickness over the cavity on the reduction of the adhesive force. Applying pressure to the inner cavity of the pillars changes the sphericity, which alters the adhesive force accordingly. The sphericity 0.1 almost has no effect on the tunable adhesion strength, where the higher sphericity results in the reduction of the adhesive force from high adhesive force to low adhesive force linearly with a tunable efficiency between 95% and 98%.

Optimized Design, Fabrication and Characterization of PZT Unimorph Microactuators for Deformable Mirrors

2004 ◽  
Author(s):  
Yoshikazu Hishinuma ◽  
Eui-Hyeok Yang ◽  
Jian-Gong Cheng ◽  
Susan Trolier-McKinstry
Keyword(s):  
Mathematical Model ◽  
Resonant Frequency ◽  
Excellent Agreement ◽  
Deformable Mirrors ◽  
Membrane Thickness ◽  
Optimized Design ◽  
Silicon Membrane ◽  
Bandwidth Requirement ◽  
Fabrication And Characterization

This paper describes an optimization of PZT unimorph membrane microactuators in view of their application to deformable mirrors (DMs). PZT unimorph actuators of various electrode designs, silicon membrane thickness, and membrane sizes were fabricated and characterized. A mathematical model was developed to further assist the optimization of membrane thickness and electrode sizes, and excellent agreement with experiment was obtained. For a 2.5mm diameter actuator with 2μm thick PZT and 15μm thick silicon membrane, the measured vertical stroke was 5.4μm at 50V. The measured resonant frequency of the unimorph actuator was 47kHz, far exceeding the bandwidth requirement of most DMs (~1kHz).

Ultrathin silicon membrane thickness determination by CBED and measurement of plasmon mean free path

1989 ◽  
Vol 47 ◽  
pp. 528-529
Author(s):  
Peirong Xu
Keyword(s):  
Ion Implantation ◽  
Free Path ◽  
Lower Limit ◽  
Mean Free Path ◽  
Thickness Measurement ◽  
Membrane Thickness ◽  
Silicon Membrane ◽  
Diffraction Patterns ◽  
Convergent Beam ◽  
Beam Diffraction

The lower limit of accurate thickness measurement using two beam CBED patterns is usually about one extinction distance for the reflection used. We have used (111) symmetric CBED patterns to measure thin silicon membrane thicknesses as low as 130 Å by comparing experimental patterns with computer simulated CBED patterns. The silicon plasmon mean free path was also measured using these thickness values.Symmetric convergent beam diffraction patterns of (111) silicon in the thickness range of 130 Å to 1300 Å were obtained in a VG HB501A STEM with a 5 Å probe (8 mrad convergence angle) scanning a 100 Å × 100 Å area. The sample was made by ion implantation, anodic etching and annealing. Subsequent photolithography and reactive ion etching thinned the specimen down further to as thin as 100 Å. The sample was chemically cleaned by the Shiraki method before being loaded into the microscope.

scholarly journals In SituMonitoring of Silicon Membrane Thickness during Wet Etching using a Surface Acoustic Wave Sensor

2004 ◽  
Vol 43 (6A) ◽  
pp. 3611-3617 ◽  
Author(s):  
Chi-Yuan Lee ◽  
Ying-Chou Cheng ◽  
Yung-Yu Chen ◽  
Pei-Zen Chang ◽  
Tsung-Tsong Wu ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Wet Etching ◽  
Membrane Thickness ◽  
Silicon Membrane ◽  
Acoustic Wave Sensor

Fresnel interference in point-projection imaging of purple membrane

1995 ◽  
Vol 53 ◽  
pp. 846-847
Author(s):  
X. Zhang ◽  
J. Spence ◽  
W. Qian ◽  
D. Taylor ◽  
K. Taylor
Keyword(s):  
Detection Efficiency ◽  
Mean Free Path ◽  
Purple Membrane ◽  
Unit Cell Dimension ◽  
Experimental Point ◽  
Membrane Thickness ◽  
Low Energies ◽  
Channel Plate ◽  
Point Projection ◽  
Inelastic Mean Free Path

Experimental point-projection shadow microscope (PPM) images of uncoated, unstained purple membrane (PM, bacteriorhodopsin, a membrane protein from Halobacterium holobium) were obtained recently using 100 volt electrons. The membrane thickness is about 5 nm and the hexagonal unit cell dimension 6 nm. The images show contrast around the edges of small holes, as shown in figure 1. The interior of the film is opaque. Since the inelastic mean free path for 100V electrons in carbon (about 6 Å) is much less than the sample thickness, the question arises that how much, if any, transmission of elastically scattered electrons occurs. A large inelastic contribution is also expected, attenuated by the reduced detection efficiency of the channel plate at low energies. Quantitative experiments using an energy-loss spectrometer are planned. Recently Shedd has shown that at about 100V contrast in PPM images of thin gold films can be explained as Fresnel interference effects between different pinholes in the film, separated by less than the coherence width.

Strain measurement by means of bend contour microscopy

1989 ◽  
Vol 47 ◽  
pp. 210-211
Author(s):  
Philip D. Hren
Keyword(s):  
Strain Measurement ◽  
Large Angle ◽  
Single Crystal Silicon ◽  
Convergent Beam Electron Diffraction ◽  
Zone Axis ◽  
Silicon Membrane ◽  
Crystal Silicon ◽  
Contour Pattern ◽  
Convergent Beam ◽  
Low Symmetry

The pattern of bend contours which appear in the TEM image of a bent or curled sample indicates the shape into which the specimen is bent. Several authors have characterized the shape of their bent foils by this method, most recently I. Bolotov, as well as G. Möllenstedt and O. Rang in the early 1950’s. However, the samples they considered were viewed at orientations away from a zone axis, or at zone axes of low symmetry, so that dynamical interactions between the bend contours did not occur. Their calculations were thus based on purely geometric arguments. In this paper bend contours are used to measure deflections of a single-crystal silicon membrane at the (111) zone axis, where there are strong dynamical effects. Features in the bend contour pattern are identified and associated with a particular angle of bending of the membrane by reference to large-angle convergent-beam electron diffraction (LACBED) patterns.

Three-Dimensional Structure of Rotavirus-Fab Complex

1990 ◽  
Vol 48 (1) ◽  
pp. 238-239
Author(s):  
B.V.V. Prasad ◽  
E. Marietta ◽  
J.W. Burns ◽  
M.K. Estes ◽  
W. Chiu
Keyword(s):  
Image Processing ◽  
Smooth Surface ◽  
Three Dimensional ◽  
Outer Shell ◽  
Dimensional Structure ◽  
Structural Studies ◽  
Cell Penetration ◽  
Electron Cryomicroscopy ◽  
Image Processing Techniques ◽  
Processing Techniques

Rotaviruses are spherical, double-shelled particles. They have been identified as a major cause of infantile gastroenteritis worldwide. In our earlier studies we determined the three-dimensional structures of double-and single-shelled simian rotavirus embedded in vitreous ice using electron cryomicroscopy and image processing techniques to a resolution of 40Å. A distinctive feature of the rotavirus structure is the presence of 132 large channels spanning across both the shells at all 5- and 6-coordinated positions of a T=13ℓ icosahedral lattice. The outer shell has 60 spikes emanating from its relatively smooth surface. The inner shell, in contrast, exhibits a bristly surface made of 260 morphological units at all local and strict 3-fold axes (Fig.l).The outer shell of rotavirus is made up of two proteins, VP4 and VP7. VP7, a glycoprotein and a neutralization antigen, is the major component. VP4 has been implicated in several important functions such as cell penetration, hemagglutination, neutralization and virulence. From our earlier studies we had proposed that the spikes correspond to VP4 and the rest of the surface is composed of VP7. Our recent structural studies, using the same techniques, with monoclonal antibodies specific to VP4 have established that surface spikes are made up of VP4.

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