application oriented micro-nano electro mechanical systems masayoshi esashi
DESCRIPTION
Application oriented micro-nano electro mechanical systems Masayoshi Esashi New Industry Creation Hatchery Center , Tohoku University, Sendai , Japan Ⅰ. Introduction Ⅱ. Electrostatically levitated rotational gyroscope Ⅲ. MEMS relay Ⅳ. Multi probe data storage - PowerPoint PPT PresentationTRANSCRIPT
Application oriented micro-nano electro mechanical systems
Masayoshi Esashi
New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
Ⅰ. Introduction
Ⅱ. Electrostatically levitated rotational gyroscope
Ⅲ. MEMS relay
Ⅳ. Multi probe data storage
Ⅴ. Electron field emitter array using carbon nanotube for multi-column electron beam lithography
Ⅵ. Monolithic stage
Ⅶ. Micro Molding for Harsh Environment
A. Silicon lost mold process for SiC microstructure
B. SiC microstructures for glass press molding
Ⅷ.Conclusions
MEMS process facility for 20 mm wafer
Vibrating gyroscope (yaw rate sensor) for vehicle stability control
Resonating gyroscope fabricated using Si deep RIE
Si deep RIE system(M.Takinami, 11th Sensor Symposium, (1992) p.15)
Ⅱ. Electrostatically levitated rotational gyroscope
Electrostatically levitating micromotor for rotational gyroscope (disk rotor type)
(T.Murakoshi (Tokimec Inc.) et.al., Transducers’99)
Electrostatically levitating micromotor for rotational gyroscope (disk rotor type)
(T.Murakoshi (Tokimec Inc.) et.al., Transducers’99)
10mm
Electrostatically levitating micromotor for rotating gyroscope
Max 20,000 rpm5mm
Rotor position is capacitively detected and voltage is applied to electrode
(T.Matsubara et.al., Transducers’93, 50-53)
Electrostatically levitating micromotor for rotational gyroscope (ring rotor type) (Control voltage < 15 V)(T.Murakoshi et.al. : Jpn. J. Appli. Phys., 42, Part1 No.4B (2003) pp.2468-2472)
Structure of electrostatically levitated ring rotor gyroscope
Fabrication process of electrostatically levitating micromotor for rotational gyroscope (ring rotor type)
Rotor
Gap 5μm(100μm deep)
Lateral control electrode
4mm ring : 12,000 rpm (1mm ring : 100,000 rpm)
Inertia measurement system for 2-axis rotation and 3-axis acceleration
Noise floor
Gyro : 0.002 deg/s/√Hz
Accelerometer : 10μG/ √Hz
Rotor
MESAG-1 (Micro Electrostatically Suspended Accelerometer Gyro)
Integrated capacitive pressure sensor
Circuit integration
(T.Kudoh et.al., Sensors and Actuators A,29 (1991) p.185-193)
MEMS is value added but small volume
→ Hard to commercialize because of
the high cost.
(70% of the MEMS cost is packaging
and test)
Wafer level packaging
→ low cost (minimization of assembly
investment and loss in test)
→ small size (chip size encapsulation)
→ high yield (protection of MEMS
structures during dicing)
→ reliability (hermetic sealing)
MEMS relay having electrical feedthrough made by RIE and electroplating (Y.Liu et.al., MEMS’01)
Partly removed
Micro spring contact
Packaged micro relay
High reliability (>107)
Application for LSI tester
(A.Nakamura et.al.,Advantest Technical Report, 22 (2004), 9-16)
5mm4mm
Driving power <160mW (6V)
On resistance <0.3Ω
Operation speed
<3ms
Life of contact 8×107( 3V-15mA)>20GHz
Multi probe data storage Conventional hard disk
Ⅳ. Multi probe data storage
Structure of the multiprobe data storage (D.W.Lee et.al., J. of Microelectromechanical Systems, 11, 3 (2002), 215-219)
Recording media
Conductance image of the recorded bits on thin GeSbTe (phase change media) (2m2m)
Diamond Probe for Ultra-High-Density Data Storage Based on Scanning Nonlinear Dielectric Microscopy
(H.Takahashi (Pioneer Corp.), T.Ono, Y.Cho and M.Esashi (Tohoku Univ.) MEMS’04 (2004) p.536)
N S + +-
Domain of ferromagnetics Domain of ferroelectrics
Pr
Pr
Pr
Bloch wall~50nm
Single lattice domain wall
Advantageous to record nano-size domain array
N
N
SNDM (Scanning Nonlinear Dielectric Microscopy)
(Y.Cho, Rev. Sci. Instrum. 67, (1996) p.2297)
The diamond probe array.
The end of the diamond probe. 800nm
Recording medium
LiTaO3 Thickness: 60nmWriting condition
DC Pulse: 15 V Width: 1 ms
Reading condition
AC voltage: 2.5V Frequency: 10kHz
FM signal frequency: around 1.3GHz
Conductance modification of conductive polymer
(T.Ono et.al., Nanotechnology, 14 (2003) pp.1051-1054)
(T.Ono et.al., Nanotechnology, 14 (2003) pp.1051-1054)
・ Scan speed 10m/sec
・ Recording voltage 10V
・ Reading voltage 0.4V
Dot diameter 150nm
Recording on a conductive polymer (doped polyaniline) film
Conductance is decreased by 20 times after recording.
Current image (5m×5m)
Current after writing
Ⅴ. Electron field emitter array using carbon nanotube for multi-column electron beam lithography
Concept of Multi-Column Electron Beam Lithography
Electron field emitter array with electrostatic lens
(P.N.Minh, MEMS’04
(2004), p.430)
Fabrication of electron field emitter array with electrostatic lens
CNT electron field emitter
Hot filament CVD of carbon nano tube
(H.Miyashita et.al. MEMS'2001)
Electron field emitter with carbon nano tube deposited at the Si apex
(P.H.Minh et.al. , J. Vac. Sci. Technol. B 21, 4, (2003), 1705-1709)
Effect of hydrogen treartment (Fowler-Nordheim plot)
Stability of carbon nanotube field emitter
Ⅵ. Monolithic stage
Monolithic stage fabricated from a PZT plate
(D.-Y.Zhang et.al., Digest of Technical Papers, Transducers'03, Boston (2003) 1518-1521)
Monolithic X-Y stage
X/Y Motion
Amplification factor L/W
Rotation around Z axis Z motion
Elongation vs. Applied Voltage of bimorph PZT actuator
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0 20 40 60 80 100 120Applied Voltage (V)
Dis
pla
cem
ent
(um
)
L
Z
-12.0
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
0 20 40 60 80 100 120
Dis
pla
cem
ent
(um
)
Applied Voltage (V)
Bending vs. Applied Voltage of bimorph PZT actuator
Ⅶ. Micro Molding for Harsh Environment
A. Silicon lost mold process for SiC microstructure
B. SiC microstructures for glass press molding
Si lost mold process for SiC microstructure.
(reaction sintering condition : 1700°C, 100MPa)(S.Sugimoto et.al., MEMS’2000)
SiC micro turbine made by the Si lost mold process
Gray scale exposure by exposing with programmed multiple patterns Surface profile of resist
Mask less exposure system using DMD (Ball Semiconductor INC.)
Micro lens array fabricated
(K.Totsu et.al., Sensor Symposium, Late news (2004/10/14))Gray scale mask-less exposure
Fabrication of SiC mold for glass mold press (T.Itoh et.al., Transducers'03, (2003) p.25
4)
SiC mold for glass mold press
(non-spherical lens)(K.-O.Min et.al.,The 21th Sensor Symposium, Kyoto (2004/10/14-15))
Wafer level packaging
Multiprobe data storage
Electrical feedthrough in glass
MEMS relay
SIP (System In Package) MEMS
Ⅷ.Conclusions
SiC mold for glass mold press
Electrostatically levitated rotational gyroscope
Monolithic stage