Post on 18-Jun-2020
Industrialization of Micro-Electro-Mechanical Systems
Werner WeberInfineon Technologies
Page 222-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Semiconductor-based MEMS market
MEMS Market 2004 (total 22.7 BUS$)
R/W heads
Image Sensors Opto Devices
µ-Fluidic
Inertia Sensors
Pressure Sensors
Optical MEMS
IR Sensors
Magnetic Sensors
RF MEMS
Others
mostly DigitalLight Projection
mostly inkjet printer heads
Page 322-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Growth potential of different technologies
Expected Growth Between 2004 and 2008
00,20,40,60,8
11,21,41,61,8
2
Image
Senso
rsOpto
Devices
µ-Fluidic
Inertia
Senso
rsPres
sure
Sensors
Optica
l MEMS
IR Sensors
Magnetic
Sensor
sRF M
EMS7
6,86,66,4
Page 422-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Trends in MEMS
Killer applications: the markets of Read/Write heads, OptoDevices and Digital Light Projection and Image Sensors for cameras and mobile phones have already taken offEmerging areas: acceleration sensors, pressure sensors, RF MEMS, biosensors for DNA analysis, water & air quality, body functions are future hype candidates
Page 522-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Other Trends
The growing role of system integration Integration in system on chip
Importance of packagingSeparation of sensor and logic chip plus 3D integration
More complex applications combine multiple sensor signalsApplication/customer-specific solutions (see next page)
Page 622-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Customer oriented solutions are a differentiator
Bolt weight sensor(BOSCH)
Sensor is a common part (traditional cantilever)BOSCH integrated such sensor in a regular bolt to fasten seat of car Customer just needs to replace existing bolts by new onefunctional housing of sensor - adapted to customer needs - finally yields differentiator
Page 722-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Agenda
R/W HeadsImage SensorsOptoDevicesµ-FluidicsOptical MEMS for Light TransmissionPressure Sensors InertiaMagnetic SensorsInfrared SensorsRadio Frequency MEMS
Page 822-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
R/W heads(revenue of 9.3 BUS$ in 2007)
R/W Gap
Data field
R/W Gap
Data field
Pre-Erase Gap
Conventional R/W head
Advanced R/W head
Page 922-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Image Sensors(revenue of 8.4 BUS$ in 2007)
Page 1022-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
5 Megapixel Image Sensor
source: Micron/Nokia
Page 1122-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
PhotodiodesLaser Pickup (of recorded data)Laser Transmitter
Opto Devices for light generation(revenue of 3.8 BUS$ in 2007)
Page 1222-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
µ-Fluidics(revenue of 2.3 BUS$ in 2007)
InkJet PrintingBiochip µ-PumpsNebulizerNeedleless injectorDrug deliveryMicro reactionLab-on-a-chip
Page 1322-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
DNA Detector
Mismatch Match
Single stranded DNA Single Stranded DNA with marker
I
time
I
Page 1422-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
µ-Fluidics(revenue of 2.3 BUS$ in 2007)
InkJet PrintingBiochip µ-PumpsNebulizerNeedleless injectorDrug deliveryMicro reactionLab-on-a-chip
Page 1522-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Printer heads
Ink ChamberJet Nozzle
Diaphragm
Target
Piezo device or Heater
Page 1622-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Inkjet printer in action
Simulation (increment of 25 µs) Photograph
Source: Jyi-Tyan Yeh, Industrial Technology Research Institute, Hsinchu Taiwan7th National Computational Fluid Dynamics Conference 2000 Source: M. Grove, et al., Display Works '99, 1999.
Page 1722-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Recent trend: printhead integrated into printer
…. rather than into the print cartridge - reducing the cost for replacement ink cartridges
source: Kodak/ST
Page 1822-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Optical MEMS for light transmission(revenue of 2.0 BUS$ in 2007)
Digital Light Projection/µ-displaysSwitches/ µ-mirrors AttenuatorsFiltersµ-lenses
Page 1922-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Principle of Digital Light Projection
single pixel of digital micromirror device Projection system
Page 2022-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Side airbagTPMS
Pressure Sensors(revenue of 1.6 BUS$ in 2007)
Page 2122-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Surface Micromachined Pressure Sensor integrated in 0.5µm BiCMOS
Pressure
n-MOS p-MOS 0.8µm Poly-Si-Membrane, capacitive sensing
10mbar overall accuracy
Typically two references and two sensors arranged in a bridge
Sensors for 0.1 to 3 bar, side airbag, motor management (intake pressure)
Page 2222-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Side airbagTPMS
Pressure Sensors(revenue of 1.6 BUS$ in 2007)
Page 2322-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
glass-silicon-glass stackOnly silicon oxide exposed to media. All active parts are placed on the backside of the pressure membrane.
Bulk Micromachined Tire Pressure Monitoring System (TPMS)
Pressure Inlet
Vacuum
Vacuum
Piezo resistors
Bond pads
Page 2422-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
TPMS Device Analysis: X-Ray
Page 2522-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
AccelerometerGyroscopeEnergy scavenging Microphone
Inertia Sensors(revenue of 1.4 BUS$ in 2007)
Page 2622-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
glass-silicon-glass stackOnly silicon oxide exposed to media.
Acceleration Sensor in TPMS
Vacuum
Acceleration sensor
Bond pads
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AccelerometerGyroscopeEnergy scavenging Microphone
Inertia Sensors(revenue of 1.4 BUS$ in 2007)
Page 2822-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Microphone
Spring supportedmembrane
Membrane with corrugations
Flexible Membrane
Stiff perforatedbackplate
Sound
Page 2922-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Hall sensorGiant Magnetic Resistance sensor
Magnetic Sensors(revenue of 1.1 BUS$ in 2007)
Page 3022-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Basics of Magnetic Sensing: Hall Effect
UH+
UH-
B
IUH
UV+
UV-
bd l
UH
B
Uv: Supply Voltage for Hall ProbeUH: Hall Voltage
Page 3122-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Hall Probe
di
ext_scanmode_in siclk a_testn a_testp
do
cs PGNDGND VDD
1 1
2
3
4
7 7
10 10
10
9
iddq_sup
6
5
5
11
12 13 14 15
8 16
17
18
19
20 5
Distance of Hall plates equals distance of north and south pole of magnet: 2.5mm(differential principle)
4 Hall plates for4 directions in
the plain to compensate for
noise
H2H1
Page 3222-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Measurement Principle of Hall Sensor
Differential Hall principleProgrammable Gain Amplifier (PGA) to adjust signal level to Analog Digital Converter (ADC)Analog offset compensation
Page 3322-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Giant Magnetic Resistance (GMR) principle
• spin dependent scattering of conducting electrons • sensitive to in-plane magnetic field components
parallel alignment
non-magnetic layer
ferromagnetic layer
ferromagnetic layer
anti-parallel alignment
Page 3422-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
GMR spin valve system for angle sensing
• reference layer (RL) with fixed magnetization direction• free layer (FL) with ability to follow ideally an external in-planemagnetic field
Varying angle between FL and RL magnetization leads to a continuous change in stack resistance
NAF
magnet
Page 3522-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
0 40 80 120 160 200 240 280 320 360
resi
stan
ce (a
.u.)
angle Θ (°)NAF
GMR spin valve system for angle sensing
NAF
0 40 80 120 160 200 240 280 320 360
resi
stan
ce (a
.u.)
angle Θ (°)
0 40 80 120 160 200 240 280 320 3600
50
100
150
200
250
300
350
mea
sure
d an
gle
(°)
angle Θ (°)
arctan
360°uniqueness bycombination of orthogonal RL magnetizations
Page 3622-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
360° Angular Sensor
SIN COS
Page 3722-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Advantages of GMR compared to Hall
Higher sensitivitybigger airgaplower jitter
GMR sensitive only to inplane field
bigger airgapindependent toback bias field
B
GMR
Hall
N S N S
Hall GMR
Page 3822-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
IR-temperature IR camera arrays
InfraRed Sensors(revenue of 0.8 BUS$ in 2007)
Page 3922-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Bolometer Array for Night Vision Systems
Bolometer ViasThin-Film Thermistor Free Space
Wafer
Page 4022-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Infrared Night Vision System
Page 4122-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
RF MEMS(revenue of 0.7 BUS$ in 2007)
InductorsCapacitorsBulk Acoustic Wave (BAW) resonatorsSwitchesµ-mech. resonators
Page 4222-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Bulk Acoustic Wave Device
Bottomelectrode
PiezoAlN
Top electrode
SiO2W
Trappedacoustic wave
acousticmirror
~1µm
200µm
• Si substrate• Aluminum Nitride (AlN) used as piezoelectric material• acoustic mirror realized by buried W layers
Page 4322-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
RF MEMS(revenue of 0.7 BUS$ in 2007)
InductorsCapacitorsBulk Acoustic Wave (BAW) resonatorsSwitchesµ-mech. resonators
Page 4422-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Micro-Mechanical Resonators
Source Discera
Page 4522-Sep-08 Copyright © Infineon Technologies 2006. All rights reserved.
Conclusion
MEMS have developed into a very dynamic field with exiting technical challenges and above-average growth ratesSome applications have already developed into mature applications
Read/Write heads, Digital Light Projection, OptoDevices and Image sensors for cameras and mobile phones
… others are yet developing Acceleration sensors, Pressure sensors, RF MEMS, Biosensors