Transparent thin-film metrology with a high sensitivity transmission-mode quantitative phase microscope

Author(s):  
Yujie Nie ◽  
Nanzen Zhou ◽  
Li Tao ◽  
Guodong Zhou ◽  
Ni Zhao ◽  
...  
Author(s):  
N. Osakabe ◽  
J. Endo ◽  
T. Matsuda ◽  
A. Tonomura

Progress in microscopy such as STM and TEM-TED has revealed surface structures in atomic dimension. REM has been used for the observation of surface dynamical process and surface morphology. Recently developed reflection electron holography, which employes REM optics to measure the phase shift of reflected electron, has been proved to be effective for the observation of surface morphology in high vertical resolution ≃ 0.01 Å.The key to the high sensitivity of the method is best shown by comparing the phase shift generation by surface topography with that in transmission mode. Difference in refractive index between vacuum and material Vo/2E≃10-4 owes the phase shift in transmission mode as shownn Fig. 1( a). While geometrical path difference is created in reflection mode( Fig. 1(b) ), which is measured interferometrically using high energy electron beam of wavelength ≃0.01 Å. Together with the phase amplification technique , the vertivcal resolution is expected to be ≤0.01 Å in an ideal case.


2015 ◽  
Vol 135 (6) ◽  
pp. 192-198 ◽  
Author(s):  
Shinnosuke Iwamatsu ◽  
Yutaka Abe ◽  
Toru Yahagi ◽  
Seiya Kobayashi ◽  
Kazushige Takechi ◽  
...  

2012 ◽  
Vol 1477 ◽  
Author(s):  
Horacio V. Estrada

ABSTRACTThin film bismuth piezoresistors, defined on oxidized silicon wafers, are investigated as a function of their orientation for their eventual integration on micro-electro-mechanical (MEMS) microsensors. Bismuth’s piezoresistance (or elasto-resistance) is experimentally investigated to accurately determine its longitudinal and transverse strain sensitivities. Whisker-shaped resistive elements defined on different orientations (from 0o, the beam’s main strain axis, to 90o, perpendicular to that axis) undergo changes of resistance (ΔR), associated with the induced strains on silicon cantilevers beam’s surface when these are mechanically loaded under pure bending stress conditions. For Bi-resistors, the traditional gage factor concept, (ΔR/Ro)/εl, is found to be equal to +16 and +33, for elements oriented along 0 and 90o, respectively, considerably larger than those for metals or metal alloys. These high sensitivity values and the “unusual” positive, higher value for the 90o (perpendicular) resistors can be of considerable interest for microsensors applications. The results of this study enable us to precisely determine the bismuth’s longitudinal and transverse strain sensitivities that are calculated to be equal to +26 and +40.5 respectively. This experimental study is extended to explore the Bi-films’ response to bi-axial strain fields.


2006 ◽  
Vol 320 ◽  
pp. 99-102 ◽  
Author(s):  
Kazuki Tajima ◽  
Woosuck Shin ◽  
Maiko Nishibori ◽  
Norimitsu Murayama ◽  
Toshio Itoh ◽  
...  

Micro-thermoelectric hydrogen sensor (micro-THS) with the combination of the thermoelectric effect of Si0.8Ge0.2 thin film and the Pt-catalyzed exothermic reaction of hydrogen oxidation was prepared by microfabrication process. In the viewpoint of high sensitivity of micro-THS, the thermoelectric properties of the Si0.8Ge0.2 thin film could be improved by optimizing carrier concentration using helicon sputtering with an advantage of easy doping control, and sensitivity of the device with this thin film was investigated. As the result, the boron-doped Si0.8Ge0.2 thin film is considered to be the better choice ensuring the reliable monitoring of hydrogen concentration down to ppm level.


Author(s):  
Renjie Zhou ◽  
Cuifang Kuang ◽  
Poorya Hosseini ◽  
Ravi Chowdhary ◽  
Zahid Yaqoob ◽  
...  

Micromachines ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 355 ◽  
Author(s):  
Tomoo Nakai

A thin-film magnetic field sensor is useful for detecting foreign matters and nanoparticles included in industrial and medical products. It can detect a small piece of tool steel chipping or breakage inside the products nondestructively. An inspection of all items in the manufacturing process is desirable for the smart manufacturing system. This report provides an impressive candidate for realizing this target. A thin-film magneto-impedance sensor has an extremely high sensitivity, especially, it is driven by alternatiing current (AC) around 500 MHz. For driving the sensor in such high frequency, a special circuit is needed for detecting an impedance variation of the sensor. In this paper, a logarithmic amplifier for detecting a signal level of 400 MHz output of the sensor is proposed. The logarithmic amplifier is almost 5 mm × 5 mm size small IC-chip which is widely used in wireless devices such as cell phones for detecting high-frequency signal level. The merit of the amplifier is that it can translate hundreds of MHz signal to a direct current (DC) voltage signal which is proportional to the radio frequency (RF)signal by only one IC-chip, so that the combination of a chip Voltage Controlled Oscillator (VCO), a magneto-impedance (MI) sensor and the logarithmic amplifier can compose a simple sensor driving circuit.


1995 ◽  
Vol 398 ◽  
Author(s):  
S.L. Lai ◽  
P. Infante ◽  
G. Ramanath ◽  
L.H. Allen

ABSTRACTWe introduce a high-sensitivity (∼1 J/m2) scanning microcalorimeter that can be used to perform direct calorimetric measurements on thin film samples at ultrafast heating rate (∼104 °C/s). This novel microcalorimeter is fabricated by utilizing SiN thin-film membrane technology, resulting in dramatically reduced thermal mass of the system. Calorimetric measurements are accomplished by applying a dc-current pulse to the thin-film metal (Ni) heater which also serves as a thermometer, and monitoring the real-time voltage and current of the heater. The temperature of the system and the energy delivered to the system are then determined. This calorimetric technique has been demonstrated by measuring the melting process of thin Sn films with thickness ranging from 13 to 1000 Å, and shows potential for calorimetric probing of irreversible reactions at interfaces and surfaces, as well as transformations in nanostructured materials.


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