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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
JSTS:Journal of Semiconductor Technology and Science
Journal Basic Information
Journal DOI :
The Institute of Electronics Engineers of Korea
Editor in Chief :
Volume & Issues
Volume 5, Issue 4 - Dec 2005
Volume 5, Issue 3 - Sep 2005
Volume 5, Issue 2 - Jun 2005
Volume 5, Issue 1 - Mar 2005
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Microsystems for Whole Blood Purification and Electrophysiological Analysis
Han, Arum ; Han, Ki-Ho ; Mohanty Swomitra K. ; Frazier A. Bruno ;
JSTS:Journal of Semiconductor Technology and Science, volume 5, issue 1, 2005, Pages 1~10
This paper presents the development of a microsystem for whole blood purification and electrophysiological analysis of the purified cells. Magnetophoresis using continuous diamagnetic capture (DMC) was utilized for whole cell purification and electrical impedance spectroscopy (EIS) was utilized for electrophysiological analysis of the purified cells. The system was developed on silicon and plastic substrates utilizing conventional microfabrication technologies and plastic microfabrication technologies. Using the magnetophoretic microseparator, white blood cells were purified from a sample of whole blood. The experimental results of the DMC microseparator show that 89.7% of the red blood cells (RBCs) and 72.7% of the white blood cells (WBCs) could be continuously separated out from a whole blood using an external magnetic flux of 0.2 T. EIS was used as a downstream whole cell analysis tool to study the electrophysiological characteristics of purified cells. In this work, primary cultured bovine chromaffin cells and human red blood cells were characterized using EIS. Further analysis capabilities of the EIS were demonstrated by successfully obtaining unique impedance signatures for chromaffin cells based on the whole cell ion channel activity.
Polymer/Metal Based Flexible MEMS Biosensors for Nerve Signal Monitoring and Sensitive Skin
Kim, Yong-Ho ; Hwang, Eun-Soo ; Kim, Yong-Jun ;
JSTS:Journal of Semiconductor Technology and Science, volume 5, issue 1, 2005, Pages 11~16
This paper presents fabrication process and experimental results of two different types of flexible MEMS biosensors based on polymer/metal multilayer processing techniques. One type of a biosensor is a microelectrode array (MEA) for nerve signal monitoring through implanting the MEA into a living body, and another is a tactile sensor capable of being mounted on an arbitrary-shaped surface. The microelectrode array was fabricated and its electrical characteristics have been examined through in vivo and in vitro experiment. For sensitive skin, flexible tactile sensor array was fabricated and its sensitivity has been analyzed. Mechanical flexibility of these biosensors has been achieved by using a polymer, and it is verified by implanting a MEA to an animal and mounting the tactile sensor on an arbitrary-shaped surface.
Simulation of Piezoelectric Dome-Shaped-Diaphragm Acoustic Transducers
Han, Cheol-Hyun ; Kim, Eun-Sok ;
JSTS:Journal of Semiconductor Technology and Science, volume 5, issue 1, 2005, Pages 17~23
This paper describes the simulation of a micromachined dome-shaped-diaphragm acoustic transducer built on a
thick silicon nitride diaphragm (
in radius, with a circular clamped boundary on a silicon substrate) with electrodes and piezoelectric ZnO film in a silicon substrate. Finite element analysis with ANSYS 5.6 has been performed to analyze the static and dynamic behaviors of the transducer under both pressure and voltage loadings.
Silicon Nitride Cantilever Arrays Integrated with Si Heater and Piezoelectric Sensors for SPM Data Storage Applications
Nam, Hyo-Jin ; Jang, Seong-Soo ; Kim, Young-Sik ; Lee, Caroline-Sunyong ; Jin, Won-Hyeog ; Cho, Il-Joo ; Bu, Jong-Uk ;
JSTS:Journal of Semiconductor Technology and Science, volume 5, issue 1, 2005, Pages 24~29
Silicon nitride cantilevers integrated with silicon heaters and piezoelectric sensors were developed for the scanning probe microscope (SPM) based data storage application. These nitride cantilevers are expected to have better mechanical stability and uniformity of initial bending than the previously developed silicon cantilevers. Data bits of 40 nm in diameter were recorded on PMMA film and the sensitivity of the piezoelectric sensor was 0.615 fC/nm, meaning that indentations less than 20 nm in depth can be detected. For high speed operation,
cantilever array was developed.
Fabrication of Electrochemical Sensor with Tunable Electrode Distance
Yi, Yu-Heon ; Park, Je-Kyun ;
JSTS:Journal of Semiconductor Technology and Science, volume 5, issue 1, 2005, Pages 30~37
We present an air bridge type electrode system with tunable electrode distance for detecting electroactive biomolecules. It is known that the narrower gap between electrode fingers, the higher sensitivity in IDA (interdigitated array) electrode. In previous researches on IDA electrode, narrower patterning required much precise and expensive equipment as the gap goes down to nanometer scale. In this paper, an improved method is suggested to replace nano gap pattering with downsizing electrode distance and showed that the patterning can be replaced by thickness control using metal deposition methods, such as electroplating or metal sputtering. The air bridge type electrode was completed by the following procedures: gold patterning for lower electrode, copper electroplating, gold deposition for upper electrode, photoresist patterning for gold film support, and copper etching for space formation. The thickness of copper electroplating is the distance between upper and lower electrodes. Because the growth rate of electroplating is
, the distance is tunable up to hundreds of nanometers. Completed electrodes on the same wafer had
electrode distance. The gaps between fingers are 10, 20, 30, and
and the widths of fingers are 10, 20, 30, 40, and
. The air bridge type electrode system showed better sensitivity than planar electrode.
Investigation of Pyrolyzed Polyimide Thin Film as MEMS Material
Naka, Keisuke ; Nagae, Hideki ; Ichiyanagi, Masao ; Jeong, Ok-Chan ; Konishi, Satoshi ;
JSTS:Journal of Semiconductor Technology and Science, volume 5, issue 1, 2005, Pages 38~44
Pyrolyzed polyimide is explored in terms of MEMS material. This paper describes chemical, electrical, mechanical properties of pyrolyzed polyimide (PIX-1400) thin film as MEMS material. When polyimide thin film was pyrolyzed at
for 60 minutes in
ambient, the residual ratio of pyrolyzed film thickness measured with a surface profiler is about 49 %, and the resistivity is about
. From the result of the load-deflection test, the estimated Young's modulus and initial average stress of pyrolyzed polyimide are 67 GPa and 30 MPa, respectively. As one demonstration of MEMS structures of pyrolyzed polyimide, the fabrication method of the microbridge structure is proposed for a micro heater and a resonator.
Characteristics of Surface Micromachined Pyroelectric Infrared Ray Focal Plane Array
Ryu, Sang-Ouk ; Cho, Seong-Mok ; Choi, Kyu-Jeong ; Yoon, Sung-Min ; Lee, Nam-Yeal ; Yu, Byoung-Gon ;
JSTS:Journal of Semiconductor Technology and Science, volume 5, issue 1, 2005, Pages 45~51
We have developed surface micromachined Infrared ray (IR) focal plane array (FPA), in which single
layer works as an IR absorbing plate and
thin film served as a thermally sensitive material. There are some advantages of applying
layer as an IR absorbing layer. First of all, the
has good IR absorbance within
spectrum range. Measured value showed about 60% absorbance of incident IR spectrum in the range.
layer has another important merit when applied to the top of Pt/PZT/Pt stack because it works also as a supporting membrane. Consequently, the IR absorbing layer forms one body with membrane structure, which simplifies the whole MEMS process and gives robustness Ito the structure.
Fabrication of Circular Diaphragm for Piezoelectric Acoustic Devices
Lee, Woon-Seob ; Kim, Yong-Chul ; Lee, Jin-Seung ; Lee, Seok-Woo ; Lee, Seung-S. ;
JSTS:Journal of Semiconductor Technology and Science, volume 5, issue 1, 2005, Pages 52~57
This paper describes a fabrication method of a circular diaphragm using boron etching stop method. It will be applied to acoustic transducers such as microphones or microspeakers and so on. The sensitivity is expected to be increased with the circular diaphragm through the simulation results to compare with a general rectangular diaphragm. The borondoped layer which is doped with solid source is sufficient for achieving an etching stop in 20 wt% TMAH, and the thickness is about
. The diameter of the circular silicon nitride diaphragm was measured to be 2 mm with
thickness. The fabrication of piezoelectric acoustic devices was completed.
Wafer Level Vacuum Packaged Out-of-Plane and In-Plane Differential Resonant Silicon Accelerometers for Navigational Applications
Kim, Illh-Wan ; Seok, Seon-Ho ; Kim, Hyeon-Cheol ; Kang, Moon-Koo ; Chun, Kuk-Jin ;
JSTS:Journal of Semiconductor Technology and Science, volume 5, issue 1, 2005, Pages 58~66
Inertial-grade vertical-type and lateral-type differential resonant accelerometers (DRXLs) are designed, fabricated using one process and tested for navigational applications. The accelerometers consist of an out-of-plane (for z-axis) accelerometer and in-plane (for x, y-axes) accelerometers. The sensing principle of the accelerometer is based on gap-sensitive electrostatic stiffness changing effect. It says that the natural frequency of the accelerometer can be changed according to an electrostatic force on the proof mass of the accelerometer. The out-of-plane resonant accelerometer shows bias stability of
, sensitivity of 70 Hz/g and bandwidth of 100 Hz at resonant frequency of 12 kHz. The in-plane resonant accelerometer shows bias stability of
, sensitivity of 128 Hz/g and bandwidth of 110 Hz at resonant frequency of 23.4 kHz. The measured performances of two accelerometers are suitable for an application of inertial navigation.