How is Technological Change Creating New Opportunities in Micro-Electronic
Mechanical Systems (MEMS) 5th Session of MT5009
A/Prof Jeffrey Funk
Division of Engineering and Technology Management
National University of Singapore
Sources: Clark Ngyuen’s lectures at UC Berkeley and others
Objectives
• What has and is driving improvements in cost and performance of MEMS?
• Can we use such information to
– identify new types of MEMS and applications for them?
– analyze potential for improvements in these new technologies?
– compare new and old technologies now and in future?
– better understand when the new technologies might become technically and economically feasible?
– analyze the opportunities created by these new technologies?
– understand technology change in general
Session Technology
1 Objectives and overview of course
2 Four methods of achieving improvements in performance and cost: 1)
improving efficiency; 2) radical new processes; 3) geometric scaling; 4)
improvements in “key” components (e.g., ICs)
3 Semiconductors, ICs, new forms of transistors, electronic systems
4 Bio-electronics, tissue engineering, and health care
5 MEMS, nano-technology and programmable matter
6 Telecommunications and Internet
7 Human-computer interfaces, virtual and augmented reality
8 Lighting and displays
9 Energy and transportation
10 Solar cells and wind turbines
This is Part of the Fifth Session in MT5009
Outline
• What is MEMS and what are the applications?
• MEMS and Moore’s Law (Benefits of scaling)
• Example of MEMS for filters and other components for mobile phone chips
• Example of micro-gas analyzers
• Example of MEMS for Ink Jet Printer
• Design tools for MEMS
Increasingly Detailed View of a Micro-Engine Source: http://www.memx.com/
Micro-engine Gear Train Multi-level springs that that are part of Micro-Engine
Side view of springs
Ratchet Mechanism Actuator Torsional Acutator Early Optical Switch Clutch Mechanism Anti-reverse mechanism
http://www.memx.com/
Accelerometer less detail more detail Inertial Sensor (includes accelerometer and gyroscope) less detail more detail
Another List of Applications (1)
• Accelerometer – cause airbag deployment in automobile collisions – control handheld games (Wii) or mobile phones – in PCs to stop hard disk head when free-fall is detected – Seismic imaging – Infrastructure monitoring (HP, sensing as a service, $150 B
USD)
• Gyroscopes (includes accelerometer and inertial sensor) – maintain orientation in mobile phones, automobiles
• Pressure sensors – car tires, manifold, blood pressure
• Fluid acceleration – micro-cooling of ICs, including bio-electronic ICs
Another List of Applications (2)
• Inkjet printing
– piezoelectrics or thermal bubble ejection to deposit ink on paper
• Optical switching technology (Photonics)
• Micro-mirrors
– For various types of displays
– Add a projector to your mobile phone
• Interferometric modulator display
– Used to create various colors in a display
Source: http://www.isuppli.com/MEMS-and-Sensors/MarketWatch/Pages/MEMS-Market-Rebounds-in-2010-Following-Two-Year-Decline.aspx
Outline
• What is MEMS and what are the applications?
• MEMS and Moore’s Law
• Example of MEMS for filters and other components for mobile phone chips
• Example of micro-gas analyzers
• Example of MEMS for Ink Jet Printer
• Design tools for MEMS
Figure 2. Declining Feature Size
0.001
0.01
0.1
1
10
100
1960 1965 1970 1975 1980 1985 1990 1995 2000
Year
Mic
rom
ete
rs (
Mic
rons)
Gate Oxide
Thickness
Junction Depth
Feature length
Source: (O'Neil, 2003)
In 1990s emphasis on both mechanical components and transistors
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
Accelerometer
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
Limitations of Scaling for Accelerometers
• Since displacement is proportional to size of mass in accelerometer – Smaller mass leads to weaker sensitivity to
displacement – Thus smaller features (e.g., springs) are bad
• Solution for MEMS-based accelerometers – Integrate transistors with MEMS device to
compensate for the poor sensitivity of MEMS-based accelerometers
– put transistors close to the MEMS device in order to reduce parasitic capacitance
• This led to pessimistic view towards MEMS
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
Nevertheless, improvements were made to accelerometers in the form of smaller size chips. Source: Trends and frontiers of MEMS, Wen H. Ko; Cs: sensing capacitance
But then other Applications Began to Emerge
• Gyroscopes
• Micro-fluidics
• Digital mirror device
• Optical switches
• These applications benefited from smaller sizes! Emphasis changed – from “adding transistors” to “reducing feature size”
– from “integration of transistors and mechanical functions” to chips with only mechanical functions/devices
Source: Ngyuen, Berkeley lecture
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
Benefits of Size Reduction: MEMS (2)
• Feature sizes are currently much larger than those on ICs – MEMS: around or less than one micron
– ICs: 22 nanometers (0.02 microns)
• Partly because – devices are different (e.g., much overlap of layers)
– processes (e.g., wet vs. plasma etching) are slightly different……
• The improvements and thus the opportunities are probably limitless – We just need to find the applications that will benefit from
smaller sizes and to develop those applications
Source: Nyugen’s Berkeley lectures and http://www.boucherlensch.com/bla/IMG/pdf/BLA_MEMS_Q4_010.pdf
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
Accelerometer
Smaller feature sizes also lead to more mechanical & electronic components
Outline
• What is MEMS and what are the applications?
• MEMS and Moore’s Law
• Example of MEMS for filters and other components for mobile phone chips
• Example of micro-gas analyzers
• Example of MEMS for Ink Jet Printer
• Design tools for MEMS
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
Mass is function of length (L), width (W), and h (height); Q is amplification factor, V is voltage; d is distance between bottom of beam and underlying material
Scaling of Mechanical Resonator
• Operates slightly different from guitar string • Calculations show that frequency rises as 1/L2
• Replacing anchored beam with free-free beam and reducing L (length) to 2 microns, W and H to nano-dimensions, causes frequency to rise to above 1 GHz – Inexpensive mechanical resonators can replace electrical
filters – Which also enables the use of multiple filters and thus
communication at many frequency bands (and thus cognitive radio)
• There is no theoretical limit to reducing sizes and thus increasing frequencies
Source: EE C245/ME C218: Introduction to MEMS, Lecture 2m: Benefits of Scaling I
Making Resonators with semiconductor processes/equipment
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
But actually calculations show that disks scale better than do beams or springs
(t = inner radius)
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
Build a filter with multiple disks
Source: Clark Ngyuen, August and September 2011 Berkeley lectures; RF BPF: radio frequency bypass filter
Source: Clark Ngyuen, August and September 2011 Berkeley lectures RF = radio frequency; SAW = surface acoustic wave: VCO: voltage controlled oscillators
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
Another application for MEMs in phones, GPS, and other devices
Outline
• What is MEMS and what are the applications?
• MEMS and Moore’s Law
• Example of MEMS for filters and other components for mobile phone chips
• Example of micro-gas analyzers
• Example of MEMS for Ink Jet Printer
• Design tools for MEMS
Source: Clark Ngyuen, August and September 2011 Berkeley lectures; ppb: parts per billion; ppt: parts per trillion
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
Chromatography is collective term for set of laboratory techniques for separation of mixtures
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
(1)
Source: Clark Ngyuen, August and September 2011 Berkeley lectures
(2)
Outline
• What is MEMS and what are the applications?
• MEMS and Moore’s Law
• Example of MEMS for filters and other components for mobile phone chips
• Example of micro-gas analyzers
• Example of MEMS for Ink Jet Printer
• Design tools for MEMS
Outline
• What is MEMS and what are the applications?
• MEMS and Moore’s Law
• Example of MEMS for filters and other components for mobile phone chips
• Example of micro-gas analyzers
• Example of MEMS for Ink Jet Printer
• Design tools for MEMS
MEMS design tools
• Create individual 2-D layers, stack them on top of each other, and create complex 3-D devices
• Design tools (e.g., 3D process simulator) enable designers to visualize their creations before they are built • Similar to CAD tools for ICs • Improvements in ICs lead to better CAD tools
• Design libraries have been developed which enable designers to create complex designs from multiple standard components – Similar to standard cell libraries with ICs
Source: http://www.memx.com/design_tools.htm
Design Library Process simulator
Conclusions (1)
• There appears to be many benefits from
– reducing the scale of features in MEMS
– adding more transistors to MEMS
• These benefits depend on the application and the way in which the application is implemented
• These benefits are causing many types of MEMS to experience exponential improvements in cost and performance
• This degree of change will probably create many types of entrepreneurial opportunities
Conclusions (2)
• For your presentations,
– How will an existing new application diffuse to a broader market as this scaling proceeds?
– When will a new application become technically and economically feasible as this scaling proceeds?
– To what extent will this create entrepreneurial opportunities and what kinds of opportunities?