Introduction to Microdevices and Microsystems

Transcription

1 PHYS 534 (Fall 2008) Module on Microsystems & Microfabrication Lecture 1 Introduction to Microdevices and Microsystems Srikar Vengallatore, McGill University 1 Introduction to Microsystems Outline of Lecture -Basic definitions and examples -How are they designed? -How are they manufactured? 2 1

2 Introduction to Microsystems Micro: Small Input System Output System dimensions: 1 mm to 10 cm Structural components: 10 nm to 100 μm Designed and manufactured to perform useful activity 3 LENGTH SCALES Bacteria Molecules Atoms 10-3 m = 1 mm 10-4 m = 100 μm 10-5 m = 10 μm 10-6 m = 1 μm 10-7 m = 100 nm 10-8 m = 10 nm 10-9 m = 1 nm STRUCTURES FOR MICROSYSTEMS m = 0.1 nm 4 2

3 1 m 1 mm 1 μm 1 nm Source: Kalpakjian and Schmid 5 Example 1. Integrated Circuit >1 Million wires per cm 2! No moving parts $200 Billion per year Revolutionary (Internet, computers, ) (I.B.M) 6 3

4 Cross-Section of an I.B.M Integrated Circuit Copper Silicon dioxide 1 μm Silicon Tungsten 7 Example 2: Texas Instruments Micromirrors 1 μm DIGITAL LIGHT PROCESSING (DLP) 8 4

5 9 Electron Micrograph of Texas Instruments DMD Torsional Hinge

6 Samsung DLP TVs DLP Projectors

7 13 Some Terminology Microsystems are known by many names.. Microdevices Microelectronics Microelectromechanical i l Systems (MEMS) Microsystems Technology (MST) Microfluidic systems Micro total analysis systems (micro-tas) Bio-MEMS/ Bio-microsystems Optical-MEMS/ Optical microsystems RF-MEMS (for radio-frequency MEMS) Power MEMS (micro-engines, micro fuel cells) 14 7

8 Terminology Reflects Evolution of Technology In the beginning, there was the transistor.. Invented in 1947 in Bell Labs. Nothing micro yet! 15 Walter Brattain John Bardeen William Shockley Nobel Prize in Physics (1956) 16 8

9 Use of a Transistor in an Electrical Circuit Jack Kilby, Texas Instruments 17 The World s First Integrated Circuit Aluminum Wires (Interconnects) Robert Noyce 18 9

10 Kilby: Nobel Prize for Physics (2000) Robert Noyce (co-founder of Intel) 19 Evolution of Integrated Circuits ( ) Year 1960 < 100 # of Transistors per device (4004, 8008) (386 processor) (486 processor) x10 6 (Pentium processor) (Pentium II) (Pentium 4) 20 10

11 Stage 2: From Microelectronics to Micromechanics 1970s: Realization that mechanical components can also be miniaturized Emergence of micromachined pressure sensors Sealed Vacuum Cavity Membrane Pressure Port (P) 21 Pressure Sensors: Principle of Operation Estimate pressure by measuring deflection 8 mm 22 11

12 Micromachined Pressure Sensors are now Widely Used s: Micro Sensors and Actuators Sensors for force, acceleration, pressure, mass,. Micromachined Accelerometers Analog Devices ~8 million accelerometers are manufactured each year 24 12

13 Principle of Operation of Accelerometer k m F = ma kδ a = a F = kδ m δ Quasi-Static Accelerometer 25 Applications for Micromachined Accelerometers Modal analysis of vibratory systems Navigation Crash Sensors: Air-bag deployment in automobiles Protection of hard-disks in laptop computers Video games

14 1980s Micro Actuators: Motion in Microsystems ELECTROSTATIC ACTUATORS Linear Spring, k Mass, m Gap, g 0 + V _ g < g 0 Fixed electrode Micro Electro + Mechanical System, or MEMS 27 Types of Microscale Actuators Electrostatic Thermal Piezoelectric Shape Memory Alloy Motion is either due to Applied Forces or Differential Expansion and Contraction 28 14

15 THERMAL ACTUATORS α 1 α 2 α 1 > α 2 Heat s: Increasing Focus on Commercialization Important Trends Microsystem community focused on Utility (design, manufacture, marketing, reliability, cost, etc.) Range expanded from Electro + Mechanical to multiple energy domains Optical Chemical Radio-Frequency communications Biological Fluidic There is a complete world of engineering at these scales! 30 15

16 OPTICAL MICROSYSTEMS FOR DISPLAYS Silicon Light Machines 31 OPTICAL MICROSYSTEMS FOR COMMUNICATIONS 32 16

17 OPTICAL CROSS-CONNECTS Lucent 33 OPTICAL MICROSYSTEMS FOR SENSING POLYCHROMATOR 10 μm 34 17

18 1990s: Microfluidics and Bio-Microsystems Texas Instruments D. Therriault, Ecole Polytechnique 35 Microfluidic Networks 36 18

19 1990s: Micro Needles for Painless Drug Delivery Georgia Institute of Technology 37 IMPLANTABLE CHIPS FOR PROGRAMMED DRUG DELIVERY 38 19

20 Microchips 39 EMERGING APPLICATIONS: PORTABLE POWER GENERATION Direct Methanol Fuel cell Toshiba V for 5 hours with one cartridge No recharge times 40 20

21 Micro Gas Turbine Engine MIT 41 Micro Solid-Oxide Fuel Cells Anode (NiO-YSZ) Électrolyte (YSZ) Cathode (LSM) McGill University/ Ecole Polytechnique 42 21

22 Refining our Terminology In this course, we will use MICROSYSTEMS as a synonym for Microdevices Microelectronics Microelectromechanical Systems (MEMS) Microsystems Technology (MST) Microfluidic systems Micro total analysis systems (micro-tas) Bio-MEMS/ Bio-microsystems Optical-MEMS/ Optical microsystems RF-MEMS (for radio-frequency MEMS) Power MEMS (micro-engines, micro fuel cells) 43 Microsystems are useful. Computation Information storage & display Optical telecommunications Sensing (force, mass, acceleration, chemistry, biology,.) Actuator technology Portable power generation Energy storage Microscale chemical synthesis and analysis Medical diagnostics Therapeutics (drug delivery)

23 Estimated Global Market for Microsystems Device Applications Market Integrated Information & >$250 Billion Circuits Communications Ink-Jet Nozzles Accelerometers Pressure Sensors DNA Microarrays Printers Automobiles Genome sequencing ~$10 billion Drug delivery, fuel cells, microneedles, etc. (in advanced stages of commercialization) 45 Outline of Lecture Introduction to Microsystems -Basic definitions and examples -How are they designed? -How are they manufactured? 46 23

24 47 How are they Designed? Formulate a plan to satisfy a need or solve a problem*. If this plan results in the creation of something having a physical reality, then the product must be: -Functional -Safe -Reliable -Competitive -Usable -Manufacturable -Marketable *JE Shigley, CR Mischke & RG Budynas, Mechanical Engineering Design 48 24

25 Ashby s Approach to Design Market need Creativity & experience Concept Evaluation of competition Manufacturing considerations Embodiment Behavioral models In-house expertise Detail Management decisions Product Specification 49 Modeling and Analysis of Microsystems Microsystems operate in multiple energy domains (mechanical, fluidic, electrostatic, thermal, magnetic, ) Frequently, coupling between different domains (electromechanical; thermoelastic; magnetomechanical,..) Critical question: validity of continuum physics 50 25

26 Approach to Structural Design What kind of STRUCTURES (Machine elements) to use? Beams, plates, rods, or membranes? Solid section or shaped cross-section? Monolithic or composite? Electrostatic or electrothermal actuation? What kind of MATERIALS to use? Ceramics, metals, or polymers? Fiber-reinforced composites or layered composites? Structural Design is Constrained by Manufacturing Limitations 51 How are they manufactured? Starting Material Flat Plate (substrate; wafer) Add material Remove Material Pattern transfer (Photolithography) Package microdevice! 52 26

27 Overview of Microdevice Manufacture Starting Material: Substrate (wafer) Subtractive Processes Wet etching Dry etching Plasma etching DRIE Polishing Processes Patterning Additive Processes Photolithography E-beam lithography Ion beam lithography Soft lithography Evaporation Sputtering CVD Electrodeposition Wafer bonding Package Microdevice 53 Catalog of Manufacturing Processes Patterning Techniques: Photolithography, Microstamping, Electron/ion beam lithography, Soft lithography, Additive processes: Thin-film deposition, wafer bonding, oxidation, epitaxy,.. Subtractive processes: Wet etching, dry etching, ion milling, deep reactive ion etching, We will study these processes in GREAT DETAIL! 54 27

28 Where are they Made (Fabricated)? Need Clean Room Fabrication Facilities (Fabs) Micromachining = Microfabrication = Microdevice Manufacture

29 NanoTools Microfabrication Facility at McGill University Basement of the Rutherford Physics Building 57 Images courtesy of Sandia National Laboratories 58 29

30 Fundamentally Different Approach to Manufacturing Parallel manufacture of hundreds of devices Simultaneous manufacture & assembly of components Layer-by-layer manufacture 10 6 mirrors 6x10 6 moving parts 59 Objective of this Module: Manufacturing of Microsystems This is an area of very active research Focus on: Fundamental principles + Established methods Science lags behind technology (We will use it even if we don t understand why it works!) Learn ideas, but also some crucial details Learn by assimilation: Case Studies 60 30

31 Market Need MECH 553: Design and Manufacture of Microdevices System concept Device concept Structural Embodiment Design Requirements Structural Embodiment Process Constraints Details Microdevice Additive Processes (Thin film deposition) Processes Pattern formation (Photolithography) Subtractive processes (Etching) 61 31