C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC'06
Meeting, 1/25-26/05. DARPA. Angle set by mechanical means to control the path
of ...
DARPA
From MEMS to NEMS: Smaller Is Still Better Clark T.-C. Nguyen Dept. of Electrical Engineering & Computer Science University of Michigan Ann Arbor, Michigan 48105-2122 (Last Month: Program Manager, DARPA/MTO) MARC’06 Meeting Jan. 25-26, 2006 C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
DARPA
Outline
• Introduction:
ª MEMS technology ª integration with transistors: an early driver for MEMS • Benefits of Scaling ª size reduction ª speed, energy conservation, complexity, economy • DARPA/MTO Program Examples ª Nano Mechanical Array Signal Processors (NMASP) ª Chip-Scale Atomic Clock (CSAC) ª Micro Gas Analyzers (MGA) • Conclusions (What’s Next?)
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
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MEMS: Micro Electro Mechanical Systems
• A device constructed using micromachining (MEMS) tech. • A micro-scale or smaller device/system that operates mainly via a mechanical or electromechanical means • At least some of the signals flowing through a MEMS device are best described in terms of mechanical variables, e.g., displacement, velocity, acceleration, temperature, flow Input: voltage, current acceleration, velocity light, heat … Transducer Transducerto to Convert Control Convert Control to toaaMechanical Mechanical Variable Variable(e.g., (e.g., displacement, displacement, velocity, velocity,stress, stress, heat, heat,…) …)
MEMS
Output: voltage, current acceleration, velocity light, heat, … [Wu, UCLA]
Control: voltage, current acceleration velocity light, heat, …
Angle set by mechanical means to control the path of light C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
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Other Common Attributes of MEMS
• Feature sizes measured in microns or less 80 mm
Gimballed, Spinning Macro-Gyroscope
[Najafi, Michigan]
Micromechanical Vibrating Ring Gyroscope
MEMS Technology (for 80X size Reduction)
1 mm Signal Conditioning Circuits
• Merges computation with sensing and actuation to change
the way we perceive and control the physical world • Planar lithographic technology often used for fabrication ª can use fab equipment identical to those needed for IC’s ª however, some fabrication steps transcend those of conventional IC processing C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
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Bulk Micromachining and Bonding Micromechanical Vibrating Ring Gyroscope
• Use the wafer itself as the
structural material • Adv: very large aspect ratios, thick structures • Example: deep etching and wafer bonding
1 mm [Najafi, Michigan]
Movable Silicon Substrate Structure Silicon Substrate
Electrode
Glass Substrate Metal Interconnect
[Pisano, UC Berkeley]
Anchor
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
Microrotor (for a microengine)
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Surface Micromachining
• Fabrication steps compatible with planar IC processing
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
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Single-Chip Ckt/MEMS Integration
• Completely monolithic, low phase noise, high-Q oscillator (effectively, an integrated crystal oscillator)
Oscilloscope Output Waveform [Nguyen, Howe [Nguyen, Howe1993] 1993]
• To allow the use of >600oC processing temperatures,
tungsten (instead of aluminum) is used for metallization
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
DARPA
Technology Trend and Roadmap for MEMS
Number of Transistors
increasing ability to compute
109
Pentium 4
108 107
CPU’s
106
ADXL-50
105 104 103 102 101
Distributed Structural Control
Terabit/cm2 Data Storage
Digital Micromirror Device (DMD)
Phased-Array Displays Inertial Navigation OMM 32x32 Antenna Integrated Fluidic On a Chip Systems i-STAT 1 Adaptive Weapons, Caliper Optics Safing, Arming, Future MEMS and Fusing Integration Levels Optical Switches & Aligners ADXL-278 Enabled Applications ADXRS ADXL-78
100 0 10 Majority of
Early MEMS Devices (mostly sensors)
101
102
103
104
105
106
107
Number of Mechanical Components increasing ability to sense and act
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
108
109
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Benefits of Size Reduction: IC’s
• Numerous benefits attained by scaling of transistors: Lower Power
Higher Current Drive Lower Capacitance Higher Integration Density Lower Supply Voltage
Faster Speed
Higher Circuit Complexity & Economy of Scale
• But … some drawbacks: ª poorer reliability (e.g., hot e- effects) ª lower dynamic range (analog ckts suffer)
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
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Example: Micromechanical Accelerometer
• The MEMS Advantage:
400 μm
Tinymass massmeans means ª >30X size reduction forTiny small output Ö need small output Ö need accelerometer mechanical element integrated integratedtransistor transistor ª allows integration with IC’stotocompensate circuits circuits compensate
Basic Operation Principle xo
x ∝ Fi = ma
x
Displacement Spring
a
Inertial Force Proof Mass Acceleration Analog Devices ADXL 78
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
DARPA
Technology Trend and Roadmap for MEMS
Number of Transistors
increasing ability to compute
109
Pentium 4
108 107
Distributed Structural 2 8x8 Optical Control OMM Terabit/cm Cross-Connect Switch Data Storage
CPU’s ADXL-50
Adv.: switching, Phased-Array Displays Adv.:faster faster switching,low low loss, larger networks Antenna OMM loss, 32x32 larger networks
Analog 10 Devices ADXRS 6 Integrated Gyroscope Inertial
Navigation Adv.: Adv.:small smallsize sizeOn a Chipi-STAT 1 Adaptive Weapons, Caliper 104 Optics Safing, Arming, and Fusing 103 Optical Switches & Aligners ADXL-278 2 10 ADXRS Caliper Microfluidic Chip ADXL-78
105
101
Early MEMS Devices (mostly sensors)
Integrated Fluidic Systems Future MEMS Integration Levels Enabled Applications
TI Digital Micromirror Device
100 0 10 Majority of
Digital Micromirror Device (DMD)
101
102
103
104
Adv.: Adv.:low lowloss, loss,fast fast switching, high fill factor 9 7 fill 105 switching, 106 10high 108factor 10
Number of Mechanical Components increasing ability to sense and act
Adv.: Adv.:small smallsize, size,small small sample, analysis speed C. T.-C. Nguyen, “From MEMSfast to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05 fast analysis speed sample,
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Benefits of Size Reduction: MEMS
• Benefits of size reduction clear for IC’s in elect. domain
ª size reduction Ö speed, low power, complexity, economy • MEMS: enables a similar concept, but …
MEMS extends the benefits of size reduction beyond the electrical domain Performance enhancements for application domains beyond those satisfied by electronics in the same general categories Speed
Frequency Ç , Thermal Time Const. È
Power Consumption
Actuation Energy È , Heating Power È
Complexity
Integration Density Ç , Functionality Ç
Economy
Batch Fab. Pot. Ç (esp. for packaging)
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
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Nano Mechanical Array Signal Processors (NMASP)
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
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Basic Concept: Scaling Guitar Strings μMechanical Resonator
Vib. Amplitude
Guitar String
Low Q High Q 110 Hz
Freq.
Vibrating Vibrating“A” “A” String (110 String (110Hz) Hz)
[Bannon 1996]
Stiffness
Guitar
Freq. Equation: 1 kr fo = 2π m r Freq.
Mass
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
fo=8.5MHz Qvac =8,000 Qair ~50
Performance: Lr=40.8μm mr ~ 10-13 kg Wr=8μm, hr=2μm d=1000Å, VP=5V Press.=70mTorr
3CC 3λ/4 Bridged μMechanical Filter
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Performance: Performance: fof =9MHz, BW=20kHz, PBW=0.2% o=9MHz, BW=20kHz, PBW=0.2% I.L.=2.79dB, I.L.=2.79dB,Stop. Stop.Rej.=51dB Rej.=51dB 20dB 20dBS.F.=1.95, S.F.=1.95,40dB 40dBS.F.=6.45 S.F.=6.45
VP In
Out
Transmission [dB]
0 -10 -20
Pin=-20dBm
Sharper Sharper roll-off roll-off
-30
Loss LossPole Pole
-40 -50 [S.-S. Li, Nguyen, FCS’05]
-60 8.7
[Li, et al., UFFCS’04]
8.9
9.1
Frequency [MHz]
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
Design: Lr=40μm Wr=6.5μm hr=2μm Lc=3.5μm Lb=1.6μm VP=10.47V P=-5dBm 9.3 RQi=RQo=12kΩ
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Nanomechanical Vibrating Resonator
• Constructed in SiC material w/ 30 nm Al metallization for magnetomotive pickup
Design/Performance: Design/Performance: μm, Wr =120 nm, h= 75 nm LLr =1.1 r =1.1 μm, Wr =120 nm, h= 75 nm fof =1.029 =1.029GHz, GHz,QQ=500 =500@ @4K, 4K,vacuum vacuum
h
Lr
Wr
Magnetomotive Resp. [nV]
o
[Roukes, Zorman 2002]
Frequency [GHz] C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
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Scaling-Induced Performance Limitations Mass Loading Noise Contaminant Molecules
Temperature Fluctuation Noise
[J. R. Vig, 1999]
Photons
1 k f = o 2π m
Nanoresonator Volume ~10-21 m3
Nanoresonator Mass ~10-17 kg
• Differences in rates of
• Absorption/emission of
photons adsorption and desorption of contaminant molecules ª temperature fluctuations ª mass fluctuations ª frequency fluctuations ª frequency fluctuations • Problem: if dimensions too small @ phase noise significant! • Solution: operate under optimum pressure and temperature
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
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1.51-GHz, Q=11,555 Nanocrystalline Diamond Disk μMechanical Resonator
• Impedance-mismatched stem for
reduced anchor dissipation • Operated in the 2nd radial-contour mode • Q ~11,555 (vacuum); Q ~10,100 (air) Design/Performance: • Below: 20 μm diameter disk R=10μm, t=2.2μm, d=800Å, VP=7V
Polysilicon Electrode
CVD Diamond μMechanical Disk Resonator
R
Ground Plane
Mixed Amplitude [dB]
Polysilicon Stem (Impedance Mismatched to Diamond Disk)
fo=1.51 GHz (2nd mode), Q=11,555
-84 -86 -88 -90 -92 -94
fo = 1.51 GHz Q = 11,555 (vac) Q = 10,100 (air)
Q = 10,100 (air)
-96 -98 -100 1507.4 1507.6 1507.8
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
1508
1508.2
Frequency [MHz] [Wang, Butler, Nguyen MEMS’04]
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Miniaturization of RF Front Ends Diplexer Diplexer
RF RFPower Power Amplifier Amplifier
925-960MHz 925-960MHz RF RFSAW SAWFilter Filter
897.5±17.5MHz 897.5±17.5MHz RF RFSAW SAWFilter Filter
1805-1880MHz 1805-1880MHz RF RFSAW SAWFilter Filter
Dual-Band Dual-BandZero-IF Zero-IF Transistor TransistorChip Chip
26-MHz 26-MHzXstal Xstal Oscillator Oscillator
Problem: Problem:high-Q high-Qpassives passivespose poseaa bottleneck bottleneckagainst againstminiaturization miniaturization
3420-3840MHz 3420-3840MHz VCO VCO Antenna
Mixer I
LPF
A/D
Diplexer
Wireless Phone From TX
RF BPF
I AGC
0o 90o LNA
RF PLL RXRF LO
Xstal Osc
Q A/D
Mixer Q C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
LPF
AGC
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Miniaturization of RF Front Ends QQ40,in in44sec sec DIMP
46000
Sandia’s Sandia’smicro-GC micro-GCColumn Column
DEMP
64000
3-methylhexane Toluene DMMP
80000
Solvent
Relative Intensity
Design/Measurement Design/MeasurementData: Data: 0.75m 0.75mxx100μ 100μcolumn column 0.1μ 0.1μDB-5 DB-5stationary stationaryphase phase Heart-cut Heart-cut275 275msec msecpeak peakinjection injection Temperature: Temperature:~30 ~30deg degC/sec C/sec 35-39 psi at 1 psi/sec HH2 carrier: 2 carrier: 35-39 psi at 1 psi/sec
1,6-dichlorohexane
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4.8
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Basic Approach: Separation Analyzer
Three Analytes
Compacted Slice of Analytes
Separated Analytes
Electronic Processor Pump
Pre-Concentrator
Separator
Detector
Miniaturization
Input Gas Mixture
Tiny TinyDimensions Dimensions ¾¾fast fasttime timeconstants constants Tiny ¾¾10,000X TinyDimensions Dimensions 10,000Xgain gainfactor factor ¾¾faster via fasterseparation separation viamulti-staging multi-staging ¾¾lower ¾¾enhanced lowerpower power enhancedsensitivity sensitivity ¾¾lower power lower power C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
Tiny TinyDimensions Dimensions ¾¾higher highersensitivity sensitivity ¾¾faster fasterrefresh refreshrate rate ¾¾lower lowerpower power ¾¾arrays arraysfor forspecificity specificity
Zeptogram Mass Sensors
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Nanomechanical Resonator
Nanomechanical NanomechanicalResonator Resonator
Shutter
Au Measurement Measurementnoise noiselevel level indicates indicates~7 ~7zg zgof ofresolution resolution 0
-200
-500
~100 zg
-400 -600 -800
100 100zg zgAu Auatom atom clumps clumpsresolved! resolved!
-1000 0
50
100 150 200 250 300 350
100
δ m (zg)
0
Frequency Shift (Hz)
Frequency Shift (Hz)
Nozzle
10
~7 zg
1
-1000 0.1
-1500
0
2000
-2000
Time (sec) C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
>1Hz/zg
133 MHz 190 MHz
-2500 -3000
4000
Time (s)
0
1000
2000
Mass (zeptograms)
3000
4000
ITMS: Scaling Leads to Lower Power
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• Example: ion trap mass spectrometer (ITMS) ª separate analytes by molecular weight
VRF
Detector
Stability Thresholds (dependent on mass)
Detector Output
time
vRF 100 ms
Trapped Ions
time
• Advantages of Miniaturization:
Detector
ª can support smaller mean free path Ö relaxed vacuum req. ª result: substantially lower power requirement
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
Operation at 1.7 Torr!
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1mm 1mmCylindrical CylindricalIon IonTrap Trap
Resistive ResistiveGlass Glass Drift DriftTube TubeDetector Detector
Detector Current [pA]
Channeltron Channeltron Detector Detector 0.16 0.12 0.08
Mass Massspectrum spectrumof ofDMMP DMMPby byaa single single1-mm 1-mmion iontrap trap@ @1.7 1.7Torr Torr Highest Highestpressure pressure ever everdemonstrated! demonstrated!
0.04
Test TestJig Jig(vacuum (vacuum chamber insert) 90 100 80 chamber insert) C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
110
120
m/z
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40μm-Ion Traps Functional!
Array Arrayof of40μm 40μmSi SiIon IonTraps Traps
Heavily-Doped Polysilicon
Oxide
Aluminum
Silicon Xenon Xenonsignal signalobtained obtainedat at -4 low lowHe Hepressure pressure(10 (10-4Torr) Torr) Xe Xeion ionpeak peak
• Should allow much higher pressure operation (~76 Torr)
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
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Gas Analyzer Technology Progression
Agilent 6852A Vol: 60,000 cm3 Power: 20 W Energy/Analysis: 18 kJ Analysis Time: 15 min.
Gas GasChromatograph/Mass Chromatograph/Mass Spectrometer Spectrometer(GC/MS) (GC/MS)isis aa“gold “goldstandard” standard”in in chemical gas detection chemical gas detection with withexcellent excellentimmunity immunity to false alarms to false alarms Problems: Problems:too toobig, big,too too slow, power hungry slow, power hungry
LLNL Vol: 40,500 cm3 Power: 11.5 W Energy/Analysis: 10 kJ Analysis Time: 15 min.
¾¾small smallenough enoughfor for projectile delivery projectile delivery ¾¾11ppt pptdet. det.limit limit ¾¾very fast very fast ¾¾battery batteryoperable operable
Sandia μChem Lab Vol: 1,050 cm3 Power: 4.5 W Energy/Analysis: 540 J Analysis Time: 2 min.
Solution: Solution:use useMEMS MEMS technology technologyto tominiaturize miniaturize the GC/MS, which the GC/MS, whichin inturn turn makes it faster and more makes it faster and more energy energyefficient efficient
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
MGA Objective Vol: 2 cm3 Power: 30X size reduction forTiny small output Ö need small output Ö need accelerometer mechanical element integrated integratedtransistor transistor ª allows integration with IC’stotocompensate circuits circuits compensate
Basic Operation Principle xo
x ∝ Fi = ma
x
Displacement Spring
a
Inertial Force Proof Mass Acceleration Analog Devices ADXL 78
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05
DARPA
Conclusions
• MEMS are micro-scale or smaller devices/systems that operate mainly via a mechanical or electromechanical means • MEMS Ö NEMS offer the same scaling advantages that IC technology offers (e.g., speed, low power, complexity, cost), but they do so for domains beyond electronics:
SizeÈ
resonant frequencyÇ (faster speed) actuation forceÈ (lower power) # mechanical elementsÇ (higher complexity) integration levelÇ (lower cost)
• Micro … nano … it’s all good • Just as important: MEMS or NEMS have brought together
people from diverse disciplines Ö this is the key to growth! • What’s next? Ö Nano-nuclear fusion? Chip-scale atomic sensors?
… limitless possibilities …
C. T.-C. Nguyen, “From MEMS to NEMS: Smaller Is Still Better,” MARC’06 Meeting, 1/25-26/05