EMT 432/4

Lecturers
• Assoc. Prof Zaliman Sauli (W1-W6: Lecture 1-10)
• Ramzan b. Mat Ayub (W7-W14: Lecture 11-24)
• BSc (Physics)
• MSc (Microelectronics)
• 14 years + with Mimos Semiconductor
• Process Integration Manager (CMOS and NVM process)
• email:
• hp: 012-2749986
• 3 rd Floor, Block B, Kompleks PPK Jejawi.

Lecture Plan (1 st Part by PM Zaliman Sauli)
• Lecture 1 & 2
•MEMS Overview
• Lecture 3 & 4
• MEMS Micromachining Technology
• Lecture 5 & 6
• MEMS Design, Simulation and Layout
• Lecture 7 & 8
• Electronic Interfaces, Packaging and Testing
• Lecture 9 & 10
• MEMS Device and Applications

Lecture Plan (2 nd Part by Ramzan Mat Ayub)
• Lecture 11
• Introduction to Semiconductor Process Technology
• Lecture 12
• Clean room Technology *
• Lecture 13
• Clean room Protocol *
• Lecture 14
• Safety and SOP *
• Lecture 15
• Basics of Semiconductor

Lecture Plan (2 nd Part by Ramzan Mat Ayub)- cont..
• Lecture 16
• Semiconductor Materials
• Lecture 17
• Silicon Process Technology
• Lecture 18
• Vacuum Technology
• Lecture 19
• Wafer Cleaning
• Lecture 20
• Thermal Processes

Lecture Plan (2 nd Part by Ramzan Mat Ayub)- cont..
• Lecture 21
• Lithography Process
• Lecture 22
• Masking and Reticle Fabrication *
• Lecture 23
• Etching Processes
• Lecture 24
• CVD and PVD Processes
• Multi Level Interconnect for the VLSI Process Technology
• Process & Device Integration, Process Technology Development

Course Evaluation
• Final Examination: 40%
• Course work: 60%
• Details on the course work contribution:
• Laboratory: 30%
• W1 - W6 Design Lab
• W7 - W10 Fabrication Lab
• W11 - W14 Mini Project
• Tests & Quizzes: 20%
• Mini Project: 10%

• Technology in General
• Operations Principles
• MEMS Applications
• MEMS Fabrication Process Technology (microelectronics)
• MEMS Micromachining Technology (micromechanical)
• MEMS World Market

What is MEMS Technology?
Micro-Electro-Mechanical Systems (MEMS) is the integration of mechanical elements, sensors, actuators, and electronics on a common silicon substrate through microfabrication technology. While the electronics are fabricated using integrated circuit (IC) process sequences (e.g., CMOS, Bipolar, or BICMOS processes), the micromechanical components are fabricated using compatible "micromachining" processes that selectively etch away parts of the silicon wafer or add new structural layers to form the mechanical and electromechanical devices
Typical MEMS contains components of sizes from 1um to 1 mm
MEMS components microelectronics + micromachining = MEMS

What is Microsystem?
A microsystem is an engineering system that contain MEMS components that are designed to perform specific engineering functions. Microsystem generally consists of 3 major components:
• processing unit (brain – decision making)
• microsensors (input for decision making)
• actuators (output or action as a result of decision making)
MEMS + processing unit = microsystem

Power supply
Signal transduction
And processing unit sensors microsystem actuators

Nanogear and bug
Thermal actuator

Nano Clutch
MEMS transmission

MEMS Category by the Principle of Operations
• Microsensor
• Microactuator
• Microaccelerometer
• Microfluidics

MEMS as a microsensor
Input signal
Power supply
Microsensing element
Transduction unit output signal
• A sensor is a device that converts one form of energy into another and provides the user with a usable energy output in response to a specific measurable input.
Pressure sensor – to convert the kinetic energy required to deflect the thin diaphragm into an electrical energy.
• Types of micro sensors
• thermal and pressure sensors
• optical sensors
• biosensors etc.

MEMS as a microsensor …cont
Power supply
Input signal
Microsensing element
Transduction unit output signal
Example: How the pressure sensor works?
• Pressure is sensed by a microsensing element (normally consists of silicon diaphragm)
• the movement of the diaphragm is converted into a change of electrical resistance by micropiezoresistors (inside the diaphragm)
• the change of electrical resistance is converted into corresponding voltage change by a micro Wheatstone bridge inside the transduction unit.

MEMS as a Microactuator
Output action
Power supply
Microactuating element
Transduction unit
Actuators are devices which transform an input signal (mainly an electrical signal) into motion. Some of the examples are; electrical motors, pneumatic actuators, relays, etc.
There are many ways microdevices can be actuated;
• by electrostatic forces
• by thermal forces
• by piezoelectric crystals

MEMS as a Microaccelerometer
Accelerometer is an instrument that measures the acceleration of a moving object. Microaccelerometers are used to detect the associated dynamic forces in a mechanical system in motion.
Basically the vibration sensor
These devices are widely used in automotive industry for example;
• acceleration sensors in suspension systems and antilock braking system (ABS)- 2g range
• air bag – 50g range
Mass M
Spring k
Typical arrangement
• M is supported by spring
• M is attached to dashpot
• Dashpot provides damping effect
• Spring and dashpot attached to casing
Dashpot with damping C
Vibrating solid body

MEMS as a Microfluidics System
Microfluidic systems are widely used in biomedical precision manufacturing processes and pharmaceutical industries. Main applications include;
• chemical analysis
• biological and chemical sensing
• drug delivery
• molecular separation such as DNA analysis
• synthesis of nucleic acid etc
• also found applications in automotive, aerospace for high precision control system
A micro fluidic system consists of:
• microsensors to measure fluid properties
• actuators (micro valves, micro pumps and compressors) to alter the state of fluid.
• distribution channel for regulating flows in various sections of the system

MEMS Applications
• Automotive Industry
• Health-care Industry
• Aerospace Industry
• Industrial Product
• Telecommunication
• Consumer Product

MEMS in Automotive Industry
• major user of MEMS early 80’s
• driving factors to use MEMS
• safer
• more comfortable
• high fuel efficiencies
• smarter product
• 4 major areas of application
• safety (use of airbag, antilock braking system, suspension system, crash avoidance, navigation).
• engine and power train (manifold control pressure sensors, airflow control, exhaust gas analysis and control, fuel pump pressure and fuel injection control, etc)
• comfort and convenience (seat control, rider’s comfort, security, satellite navigation)
• vehicle diagnostics and health monitoring (engine coolant and engine oil, tire pressure, brake oil pressure, etc)

MEMS in Health Care Industry
• disposable blood pressure transducer (DPT) – annual production 17 mil unit per year
• intrauterine pressure sensor (IUP) to monitor pressure during child delivery – 1 mil unit per year.
• angioplasty pressure sensor (heart treatment procedure) – 500k unit per year
• infusion pump pressure sensors to control the flow of intravenous fluids – 200k unit per year
• diagnostic and analytical systems
• human care support system
• respirators
• lung capacity meters
• kidney dialysis equipment
• etc

MEMS in Aerospace Industry
• Cockpit instrumentation
• pressure sensors for oil, fuel, transmission, hydraulic system
• airspeed measurement
• altimeters
• Safety devices , e.g. ejection seat controls
• Wind tunnel instrumentation
• Microgyroscope for navigation and stability control
• Microsatellites
Near future applications (< 10 years)
• Command and control systems
• Inertial guidance systems
• Power systems
• Propulsion systems
• Thermal control systems
• Communication and radar systems
• Space environment sensors

MEMS in Industrial Products
• Discreet sensors (pressure, thermal)
• Customize sensors for;
• hydraulic systems
• painting and spraying
• agricultural sprays
• air conditioning systems
• refrigeration systems
• etc

MEMS in Consumer Products
• scuba diving watches and computers
• bicycle computers
• hydraulic based fitness gear
• smart toys
• digital tire pressure gauges
• etc

MEMS in Telecommunications
• optical switching and fiber-optic couplings
• RF-MEMS switches and relays
• Tunable passive components such as inductors and capacitors

MEMS Fabrication Process (Microelectronics)
• Photolithography
• Ion Implantation
• Diffusion and Oxidation
• Deposition (CVD, sputtering, evaporation)
• Etching

MEMS Micromachining Technology (Micromechanical)
• Bulk Micromachining
• Surface Micromachining
• LIGA Process

Bulk Micromachining
• widely used in the production of microsensors and accelerometers
• 1 st used in the microelectronics in 1960s
• based on the removal of materials from the bulk substrates (usually silicon wafer) to form the desired 3D microstructures.
• General characteristics
• straightforward process, old technology
• cheap
• can only be applied on simple microstructures
• limited to low aspect-ratio geometry (<1)
Aspect ratio
1um
2um
1um
1um

Surface Micromachining
• in contrast to bulk micromachining, the surface micromachining builds microstructure by adding materials layer by layer on top of the substrate.
• Deposition technique (normally CVD) is used to deposit materials such as polysilicon.
• General characteristics
• required the building of layers of materials on the substrate
• complex masking design and production
• process is tedious and more expensive
• major advantages
• not constrained by the thickness of silicon wafers (700 um)
• wide choice of thin materials
• suitable for complex geometries

LIGA Process (Lithography, Electroforming and Molding)
• both bulk and surface micromachining has drawbacks
• low geometric aspect ratio
• use of silicon based materials i.e. limited on size and wafer thickness
• polymer and plastic not compatible
• LIGA technique is developed to overcome the above shortcomings
• can produced thick structures such as micro gear trains, motors, generators, etc
• general characteristics
• the most expensive process
• requires deep x-ray lithography
• requires microinjection molding technology
• major advantages
• unlimited aspect ration for microstructures
• flexible structure configuration and geometry
• the best process for mass production with injection molding

MEMS World Market
• Revenue Forecast 2005-2009
• Product Segment Growth 2004 vs 2009

Market forecast up to 2009
• Based on NEXUS market research, MEMS world revenue will be doubled from 12b in 2004 to 25b in 2009
• MEMS sensors and actuators will continue to consolidate their position in established
IT peripheral markets. In addition, this types of MEMS will be creating a significant new opportunities for microphone, memory etc.
• Automotive remains a major field with safety products such as airbag and tire pressure monitoring system is gaining significantly.

“The growth of consumer electronics for MEMS is breathtaking,” said
Dr Henning Wicht, managing director of Wicht Technologie Consulting.
“In this segment we see rear and front projection TVs for home theatre, as well as HDDs serving the increasing storage requirements of digital equipment such as DVD recorders, digital cameras and camcorders, and portable MP3 players.
A big driver is the mobile phone, which already features motion sensors and is amenable to a battery of additional sensors and functions like liquid lenses for camera zoom, fingerprint sensors, microfuel cell power sources, gas sensors and weather barometers,” said Dr. Wicht.

Consumer based product is forecasted the biggest growth segment