Dimensional RangesWhat aren’t MEMSPowerPoint PresentationBatch Fabrication TechnologyA Microfabricated Inertial SensorOther Batch Fabrication ProcessesMicroassembly ProcessesA Brief History of MEMS: 1. Feynmann’s Vision2. Planar IC TechnologyWhy Didn’t MEMS Take Off in 1965?Another Historical Current: Silicon Substrate (Bulk) MicromachiningWhen the Time is Right …Polysilicon MicrostructuresPolysilicon MEMS + NMOS IntegrationPolysilicon Electrostatic MicromotorElectrostatic Comb-Drive ResonatorsAnalog Devices AccelerometersSurface Micromachining FoundriesSelf-Assembly ProcessesMore Recent HistoryMEMS and Nanotechnology IMEMS and Nanotechnology II1 GHz NEMS ResonatorMEMS (NEMS?) Memory: IBM’s MillipedeElectrostatic NEMS MotorNanogap DNA JunctionsOpportunities in Blurring the MEMS/NEMS Boundary9EE C245 – ME C218 Fall 2003 Lecture 1Dimensional Ranges•1 m < L < 300 m lateral dimensionsSurface micromachined structures … “classic MEMS”•300 m < L < 3 mmBulk silicon/wafer bonded structures … still call them MEMS and cover them in this course•10 nm < L < 1 mNano electromechanical systems … NEMS(overlap with MEMS … some coverage in this course)10EE C245 – ME C218 Fall 2003 Lecture 1What aren’t MEMS•The Denso micro-car: circa 1991http://www.globaldenso.com/ABOUT/history/ep_91.html•Fabrication process: micro electro-discharge machiningIt runs!Cost?11EE C245 – ME C218 Fall 2003 Lecture 1Experimental Catheter-type Micromachine for Repair in Narrow Complex AreasWelding deviceMonitoring deviceMulti freedom bending tubeVision deviceRepairing manipulatorPosture Detecting DeviceJapanese Micromachine Project 1991-200012EE C245 – ME C218 Fall 2003 Lecture 1Batch Fabrication Technology•Planar integrated circuit technology 1958 -1. Thin-film deposition and etching2. Modification of the top few m of the substrate3. Lateral dimensions defined by photolithography, a process derived from offset printing•Result: CMOS integrated circuits became the ultimate “enabling technology” by circa 1980•Moore’s LawDensity (and performance, broadly defined) of digital integrated circuits increases by a factor of two every year.14EE C245 – ME C218 Fall 2003 Lecture 1A Microfabricated Inertial SensorMEMSIC(Andover, Mass.)Two-axis thermal-bubbleaccelerometerTechnology: standardCMOS electronics withpost processing to formthermally isolated sensorstructuresNote: I’m a technical advisor to MEMSIC a spinoff from Analog Devices.15EE C245 – ME C218 Fall 2003 Lecture 1Other Batch Fabrication Processes•Historically, there aren’t that many examples outside of chemical processes•However, that’s changing:Soft (rubber-stamp) lithographyParallel assembly processes  enable low-cost fabrication of MEMS from micro/nano components made using other batch processes … “heterogeneous integration”16EE C245 – ME C218 Fall 2003 Lecture 1Microassembly Processes Parallel assembly processes promise inexpensive, high-volume hetero-geneous integration of MEMS, CMOS, and photonicsParallel Pick-and-Placewww.memspi.com, Chris Keller, Ph.D. MSE 1998www.microassembly.comMichael Cohn, Ph.D. EECS, 1997Fluidic Self-assemblyUthara Srinivasan, Ph.D., Chem.Eng. 2001Wafer-LevelBatchAssemblyMany challenges:> interconnect> glue17EE C245 – ME C218 Fall 2003 Lecture 1A Brief History of MEMS:1. Feynmann’s Vision•Richard Feynmann, Caltech (Nobel Prize, Physics, 1965)American Physical Society Meeting, December 29, 1959: “What I want to talk about is the problem of manipulating and controlling things on a small scale. …. In the year 2000, when they look back at this age, they will wonder why it was not until the year 1960 that anybody began seriously to move in this direction.” “… And I want to offer another prize -- … $1,000 to the first guy who makes an operating electric motor---a rotating electric motor which can be controlled from the outside and, not counting the lead-in wires, is only 1/64 inch cube.” … he had to pay the electric motor prize only a year later•http://www.zyvex.com/nanotech/feynman.html18EE C245 – ME C218 Fall 2003 Lecture 12. Planar IC Technology•1958 Robert Noyce – Fairchild and Jack Kilby (Nobel Prize, Physics, 2000) -Texas Instruments invent the integrated circuit•By the early 1960s, it was generally recognized that this was the way to make electronics small … and cheaperHarvey Nathansonand William Newell,surface-micromachined resonant gate transistor, Westinghouse, 1965Did Harvey hear about Richard Feynman’s talk in 1959? I don’t think so …19EE C245 – ME C218 Fall 2003 Lecture 1Why Didn’t MEMS Take Off in 1965?•Resonant gate transistor was a poor on-chip frequency reference  metals have a high temperature sensitivity and don’t have a sharp resonance (low-Q) … specific application didn’t “fly”•In 1968, Robert Newcomb (Stanford, now Maryland) proposed and attempted to fabricate a surface micromachined electromagnetic motor after seeing the Westinghouse workEnergy density scaling for this type of motor indicated performance degradation as dimensions were reduced …Materials incompatibility with Stanford’s Microelectronics Lab research focus on electronic devices became a major issue20EE C245 – ME C218 Fall 2003 Lecture 1Another Historical Current:Silicon Substrate (Bulk) Micromachining•1950s: silicon anisotropic etchants (e.g., KOH) discovered at Bell Labs•Late 1960s: Honeywell and Philips commercialize piezoresistive pressure sensor utilizing a silicon membrane formed by anisotropic etching•1960s-70s: research at Stanford on implanted silicon pressure sensors (Jim Meindl), neural probes, and a wafer-scale gas chromatograph (both Jim Angell)•1980s: Kurt Petersen of IBM and ex-Stanford students Henry Allen, Jim Knutti, Steve Terry help initiate Silicon Valley “silicon microsensor and microstructures” industry•1990s: silicon ink-jet print heads become a commodity21EE C245 – ME C218 Fall 2003 Lecture 1When the Time is Right …•Early 1980s: Berkeley and Wisconsin demonstrate polysilicon structural layers and oxide sacrificial layers … rebirth of surface micromachining•1984: integration of polysilicon microstructures with NMOS electronics•1987: Berkeley and Bell Labs demonstrate polysilicon surface micromechanisms; MEMS becomes the name in U.S.; Analog Devices begins accelerometer project •1988: Berkeley demonstrates