MEMS for Automotive and Consumer Applications

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Colloquium, Stuttgart, IMS Chips, June 2010 1 Agenda Introduction MEMS

1 MEMS for Automotive and Consumer Applications AE/NE4 Dr. Jiri Marek Senior Vice President, Sensors Robert Bosch GmbH IEEE EDS Mini Colloquium, Stuttgart, IMS Chips, June Agenda Introduction MEMS manufacturing MEMS developments Automotive applications Consumer applications Outlook: MEMS in the future 2 1

2 Agenda Introduction Bosch MEMS sensors everywhere History of MEMS Market development MEMS manufacturing MEMS developments Automotive applications Consumer applications Outlook: MEMS in the future 3 Key data Sales revenue* 45,127 38,174 Associates 1) 281, ,687 located in Germany 114, ,710 located outside Germany 167, ,977 Capital expenditure* 3,276 1,892 Research and development cost* 3,889 3,603 Profit before tax* 942-1,197 Profit after tax* 372-1,214 1) As per January 1, 2009/2010 * Currency figures in millions of euros 4 2

Structure of the Bosch Group Bosch Group Sales: 38.2 billion euros 1) Associates on Jan.

7 billion euros Share of total sales: 57% Industrial Technology Sales: 5.

3 billion euros Share of total sales: 30% 1) Including other business areas 5 Patent ranking in

significant markets: A steady flow of bright ideas 15 new patents every working day DE: No.

3 Structure of the Bosch Group Bosch Group Sales: 38.2 billion euros 1) Associates on Jan. 1, 2010: 270,687 Automotive Technology Sales: 21.7 billion euros Share of total sales: 57% Industrial Technology Sales: 5.1 billion euros Share of total sales: 13% Consumer Goods & Building Technology Sales: 11.3 billion euros Share of total sales: 30% 1) Including other business areas 5 Patent ranking in automotive technology In automotive technology, Bosch occupies a leading position in significant markets: A steady flow of bright ideas 15 new patents every working day DE: No. 1 (Deutsches Patent- und Markenamt) EP 1) : No. 1 (European Patent Office) PCT (WIPO): No. 1 (World Intellectual Property Org.) DE, EP, WIPO: published patent applications 1) 2008 ranking 6 3

4 MEMS sensors everywhere 7 ~78% of all new cars use MEMS pressure sensors for motor management ~90% of all new cars use MEMS acceleration sensors for airbags ~28% of all new cell phones use MEMS acceleration sensors ~25% of all new digital still cameras use MEMS gyroscopes Market development consumer electronics DLP chips automotive electronics inkjet printers first applications

5 9 MEMS market Millions of Dollars displays (mainly DLP chip) sensors inkjet nozzles Other Emerging MEMS Micro Fuel Cells Flow Sensors Thermopiles Optical MEMS for Telecom Microfluidic Chips RF MEMS Oscillators MEMS Sw itches BAW Filters Microbolometers MEMS Microphones Optical MEMS for Displays MEMS Wafer Probes Gyroscopes Pressure Sensors Inkjet Print heads Accelerometers Source: isuppli Bosch the micromechanics pioneer Bosch is a micromechanics pioneer with more than 20 years of experience First product in 1993: pressure sensor for automotive applications 1 billion MEMS sensors produced 220 million units in 2009 #1 in Automotive MEMS: Bosch More than 800 patents in the MEMS sensor field Creator of the Bosch Process (Deep Reactive Ion Etch - DRIE) European inventor of the year (2007) for the Bosch process 10 5

MEMS technology surface micromachining DRIE The BOSCH process Deep RIE of silicon trenches Alternating etch- (SF 6 ) and passivation cycles (C 4 F 8 ) High aspect ratio (>> 10:1), high anisotropy and

Franz Lärmer 11 Bosch the micromechanics pioneer Bosch is a micromechanics pioneer with more than 20 years of experience First product in 1993: pressure sensor for automotive applications 1 billion

6 MEMS technology surface micromachining DRIE The BOSCH process Deep RIE of silicon trenches Alternating etch- (SF 6 ) and passivation cycles (C 4 F 8 ) High aspect ratio (>> 10:1), high anisotropy and high etch rate Licensed to many companies worldwide European Inventor of the Year 2007 for Andrea Urban and Dr. Franz Lärmer 11 Bosch the micromechanics pioneer Bosch is a micromechanics pioneer with more than 20 years of experience First product in 1993: pressure sensor for automotive applications 1 billion MEMS sensors produced 200 million units in 2008 #1 in Automotive MEMS: Bosch More than 800 patents in the MEMS sensor field Creator of the Bosch Process (Deep Reactive Ion Etch - DRIE) European inventor of the year (2007) for the Bosch process German Future Prize of the Federal President in 2008 for Bosch MEMS 12 6

Deutscher Zukunftspreis 2008 The German Federal President`s

Sensoren für Konsumelektronik, Industrie und Medizin 13

micromachining Challenges of MEMS MEMS developments

7 Deutscher Zukunftspreis 2008 The German Federal President`s innovation and advanced technology award 2008 goes to Smarte Sensoren für Konsumelektronik, Industrie und Medizin 13 Agenda Introduction MEMS manufacturing Surface and bulk micromachining Challenges of MEMS MEMS developments Automotive applications Consumer applications Outlook: MEMS in the future 14 7

8 MEMS technology overview Bulk micromachining Structure definition by selective etching of bulk wafer Structures are monocrystalline Contamination risks (potassium, natrium, ) 1 mm Surface micromachining Structures are made on top of wafer by deposition and selective etching Structures are of poly silicon and silicon dioxide Few contamination risks 20 µm 15 MEMS technology surface micromachining Thick epitaxy ( epi-poly ) DRIE ( Bosch-process ) Sacrifical etching of oxide 16 8

(Advanced porous silicon membrane) anodic

silicon transforms into a vacuum cavity by

with epitaxy process is fully CMOS compatible

porous Si n + membrane start layer membrane

9 MEMS technology surface micromachining Example: gyroscope for ESP 17 MEMS technology surface micromachining APSM technology (Advanced porous silicon membrane) anodic etching generates porous silicon porous silicon transforms into a vacuum cavity by sintering monocrystalline membrane is grown with epitaxy process is fully CMOS compatible after anodization after prebake after epitaxy porous Si n + membrane start layer membrane cavity rearranged porous Si 18 9

10 MEMS technology surface micromachining APSM technology (Advanced porous silicon membrane) piezoresistors membrane vacuum cavity old sensor substrate new sensor 19 Challenges of MEMS (1/2) Dedicated processes and equipment Source: Semitool HF vapor etch Source: Tegal DRIE Processes with contamination risks to ICs Source: EVG Anodic wafer bonding 1 mm Anisotropic etching (KOH) Combined design and control of mechanical and electrical parameters 20 µm Frequency Damping Sensitivity Capacitance 20 10

11 Challenges of MEMS (2/2) Controlling the influence of mechanical stress of package Testing of physical parameters Robustness and media compatibility (e.g. for pressure or flow sensors) air mass sensor pressure sensor 21 Agenda Introduction MEMS manufacturing MEMS developments Automotive applications Consumer applications Outlook: MEMS in the future 22 11

Package size of accelerometers Package footprint (mm²) 140 120 100

12 Package size of accelerometers Package footprint (mm²) Automotive CE mm² 23 Capability of consumer acceleration sensor Example: BMA180 from Bosch Sensortec digital triaxial acceleration sensor package LGA 3 x 3 x 0.9 mm³ resolution 0,25 mg (1G = earth s gravity) An airplane s tilt of 5 mm at the end of its wings can be detected! ~ 45m ~5mm 24 12

13 Make a guess! How many sensors are in this test tube? 25 Agenda Introduction MEMS manufacturing MEMS developments Automotive applications Combined yaw rate and acceleration sensor for ESP Working principle Noise and resolution Consumer applications Outlook: MEMS in the future 26 13

occupant protection (high-g) Acceleration

commands (Steering angle, brake pressure)

14 MEMS sensors automotive applications Airbag Systems Acceleration sensors for occupant protection (high-g) Acceleration sensors (low-g) and angular rate sensors for rollover sensing Engine Management Pressure sensors for efficient and clean engine management concepts Vehicle Dynamics Control Acceleration sensors (low-g) and angular rate sensors for VDC (ESP ) 27 ESP - Electronic Stability Program Characteristics: Surveys vehicle behavior (yaw rate and lateral acceleration) Watches the driver s commands (Steering angle, brake pressure) Intervenes if necessary (car starts to skid) by short break impulses at individual wheels or by intervention in the engine management 28 14

) MM3 SMM Silicon surface micromachining (2 nd gen) MM3R SMM MM4 SMM First ESPi sensor SMI540 SMM Combo- Inertial

15 ESP yaw rate sensor generations DRS50/100 Precision-mechanics metal housing (Electromechanical) MM1 BMM - Silicon bulk micromachining metal can (1 st gen.) MM3 SMM Silicon surface micromachining (2 nd gen) MM3R SMM MM4 SMM First ESPi sensor SMI540 SMM Combo- Inertial Sensor for ESP in moldpackage SMI540 world s first ESP combi-inertial sensor (yaw rate and acceleration) in mold-package yaw rate sensor 10,3 mm ASIC accelerometer 30 15

Micromechanical sensing element Process details Bosch SMM process Epi-Poly thickness

mbar) System aspects high resonance frequency ~15 khz antiparallel motion

performance) tight control of critical MEMS processes (lithography, trench) reduced

16 Micromechanical sensing element Process details Bosch SMM process Epi-Poly thickness ~11 μm wafer level packaging hermetic sealing (robust) vacuum encapsulation (~3 mbar) System aspects high resonance frequency ~15 khz antiparallel motion (robustness) mechanical coupling spring high Q-factor (bias stability, noise performance) tight control of critical MEMS processes (lithography, trench) reduced mechanical crosstalk 31 Working principle of yaw rate sensor Drive frame Coriolis frame Detection frame 32 16

Noise and resolution limit comparison Device sensitivity mechanical sensitivity S m ~ 5.2 pm / ( /s) electrical sensitivity S e ~ 2.3 af / ( /s) Resolution limit ~3 /h (0.

17 Noise and resolution limit comparison Device sensitivity mechanical sensitivity S m ~ 5.2 pm / ( /s) electrical sensitivity S e ~ 2.3 af / ( /s) Resolution limit ~3 /h (0.005 Hz) amplitude change in micromechanical structure ~4 fm (compares to ~ x Si-Si distance or ~ radius of atomic nucleus) capacitance change ~2 zf (μ - n - p - f - a - z) (compares to charge variation of ~0.06 electrons (at 5V)) 33 Agenda Introduction MEMS manufacturing MEMS developments Automotive applications Consumer applications Outlook: MEMS in the future 34 17

MEMS sensors the senses for mobile devices Mobile

position change Gaming and toys New gaming experience

protection by free-fall detection Sports and fitness

cases for MEMS sensors in mobile phones User

Position detection Upside down Portrait / landscape

distance estimation Altitude detection Location based

18 MEMS sensors the senses for mobile devices Mobile phones, PDAs Intuitive menu input through motion and position change Gaming and toys New gaming experience through motion interaction Mobile computing Data protection by free-fall detection Sports and fitness Monitoring through step-counting and altimetry 35 Use cases for MEMS sensors in mobile phones User interface Tap control Gaming input Menu navigation Position detection Upside down Portrait / landscape Free speech profile Pedestrian navigation Speed & distance estimation Altitude detection Location based services Motion detection Step counting Activity monitoring Power management 36 18

19 Agenda Introduction MEMS manufacturing MEMS developments Automotive applications Consumer applications Outlook: MEMS in the future 37 The Future: New applications are arising MEMS autofocus for cell phone cameras Energy Harvester for endless mobile energy Source: Siimpel Source: IMEC Micro Fuel Cell for mobile devices Micromirror for microprojectors Source: STM, CEA Source: Microvision 38 19

enables miniaturization of components and

functions in CE Key factors: size, power

20 The Future: Fusion of different MEMS 9 degrees of freedom inertial measurement unit 3D accelerometer 3D gyroscope Wireless sensor node sensor 1 sensor 2 RF module 3D magnetometer sensor energy harvester 39 Summary Automotive MEMS is main driver for sensor development Permanent enhancements of MEMS technology enables miniaturization of components and new functions Continous development of new device generations Consumer electronics MEMS is enabling technology for new functions in CE Key factors: size, power consumption, price In future large variety of new applications in many areas 40 20

21 Thank you for your attention! 41 21

MEMS for automotive and consumer electronics

MEMS for automotive and consumer MEMS for automotive and consumer electronics Dr. Jiri Marek Senior Vice President Engineering Sensors Robert Bosch GmbH, Automotive Electronics 1 Automotive Electronics