Vibrant Gujarat Summit Profile for Biotechnology and Nano Technology Sector
TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.
-
Upload
ursula-ray -
Category
Documents
-
view
212 -
download
0
Transcript of TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.
![Page 1: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/1.jpg)
TOPICS IN (NANO) BIOTECHNOLOGY
Microfabrication techniquesJanuary 9th, 2007
PhD Course
![Page 2: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/2.jpg)
Introduction
![Page 3: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/3.jpg)
Microsystem components
![Page 4: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/4.jpg)
Definition
![Page 5: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/5.jpg)
Terminology
![Page 6: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/6.jpg)
Benefits of Microsystems
![Page 7: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/7.jpg)
Benefits of microsystems
![Page 8: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/8.jpg)
Benefits of Microsystems
![Page 9: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/9.jpg)
Benefits of Microsystems
![Page 10: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/10.jpg)
History
![Page 11: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/11.jpg)
Applications
![Page 12: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/12.jpg)
Example...
![Page 13: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/13.jpg)
Microsensors
![Page 14: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/14.jpg)
Microactuators
![Page 15: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/15.jpg)
Microfluidics
![Page 16: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/16.jpg)
Microsystem Applications
![Page 17: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/17.jpg)
Concentrated System in a Single Box
Bipolar, BCD, CMOSBiCMOS, VIP,µ-Machining
Power Management
InformationProcessing(Super Integration)
MultifunctionPeripheral (System
Oriented Tech.)
Data Acquisitionand Conversion
Bipolar, CMOS,RF-BiCMOS,µ-Machining
Central Processing(µP, DSP)
Digital CMOS
PowerActuators
Bipolar, BCD,CMOS, HVCMOS,VIP, µ-Machining
Memories
CMOS, Flash,DRAM, µ-Machining
Line, Batteries,Alternators, Solar Cells, Fuel Cells
Sensors
Antennas
Keyboards
LineInterfaces
Switches
Clock Clock
Clock
Lamps
Motors
Displays
Solenoids
Speakers
CRTs
Inkjets
Antennas
![Page 18: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/18.jpg)
Microfabrication - applications
![Page 19: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/19.jpg)
Microfabrication - applications
![Page 20: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/20.jpg)
History of Lab-on-a-Chip-Systems and µTAS
1975: Gas chromatograph by S. Terry (Stanford-University)
1990: Micro channel liquid chromatograph
1990: „Micro Total Analysis System (µTAS)“ introduced by A. Manz
1992: Development of first capillary electrophoresis chips
1994: massive increase of publication about Lab-on-a-Chip and µTAS
1998: First PCR-micro chips
End 90th: Start of several Lab-on-a-Chip- and Bio-MEMS-companies
![Page 21: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/21.jpg)
Applications of Lab on a Chip
• Medical diagnostics (PoC, …)
• Pharmaceutical development (HTS, HCS, …)
• Environmental analysis (monitoring, portable analysis, …)
• Food analysis
• Process control
• Process development (screening)
• Small scale production (e.g. fine chemicals, rare molecules, …)
µTAS
![Page 22: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/22.jpg)
Design Scheme for a Lab on a Chip / µTAS
Sample inlet
Target identification• DNA primer• Antibody• Aptamers
Amplification• Enzymatic reaction• PCR / NASBA• “Secondary reaction”
Sample preparation• Cell sorting• Filtration• Washing• Cell lysis• Purification
Sensor
• Electrochemical / Amperometric / Voltametric / Impedance /…
• Optical / Fluorescence / Absorption /…
• Mechanical / Oscillator / Deflection / …
• Temperature
Instrument output
User
![Page 23: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/23.jpg)
Lab-on-a-Chip Systems
Generic Characteristics
• Integrated
• Miniaturized (Small channels)
• Automatic operation
![Page 24: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/24.jpg)
Lab-on-a-Chip Systems: Derived Characteristics
• Low chemistry consumption
• Laminar fluidics
• High control (no chaotic processes)
• Fast diffusion (fast operation for diffusion limited processes)
• Easy parallelization
• “New” effects due to smaller dimensions
• Higher production costs (with respect to system volume)
![Page 25: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/25.jpg)
What is special in µ-fluidics?… At least one characteristic dimension in the
micron range (1-100 µm)
• Inertia has low effects
• Surface tension is dominant
• Gravity has minor importance
• Mixing is due to diffusion mainly (not due to convection)
• Fast heat transfer due to small distances
• High Surface-To-Volume: Inhomogeneous reactions (surface reaction) are essential (e.g. catalysis, sensors, unspecific binding)
• …
![Page 26: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/26.jpg)
Challenges during developmentPerformance
• Sensitivity
• Selectivity
• Reproducibility
Hardware
• Speed of development
• Availability of sufficient systems /chips
Know how
• Intellectual property situation
• Theoretical understanding
![Page 27: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/27.jpg)
Challenges for commercialization
• Robustness
• Reproducibility (QM, GMP, …)
• Approval of the product (CE, FDA, …)
• Self life
• Pricing
• Availability of sufficient systems (producibility of the product)
![Page 28: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/28.jpg)
Reaction
Protocol
• Metering of sample
• Mixing of sample and reagents
• Optical detection
Detection principle
• Absorption at 545 nm
Lab-on-a-Chip an Example
![Page 29: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/29.jpg)
Commercial Systems: Glucose detection
Roche; AccuCheck
Glucose in blood
Lifescan; SureStep Flexx
Glucose monitor
![Page 30: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/30.jpg)
Commercial Systems: Blood Analyzer
Abbott; i-STAT
Siemens; Quicklab
CARESIDE
Analyzer
![Page 31: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/31.jpg)
Commercial SystemsAdvalytix
1 µl PCR slides for forensic
![Page 32: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/32.jpg)
Commercial Systems
Nanostream; Velove microparallel LC
(micro parallel liquid chromatography)
Tecan; LabCD(development stop 7.05)
Gyros; Gyrolab
![Page 33: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/33.jpg)
Commercial Systems
Agilent/Caliper
Product: Bioanalyser
Electrophoresis
![Page 34: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/34.jpg)
Commercial Systems
Aclara Biosciences
Product: Labcard
(Electrophoresis)
![Page 35: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/35.jpg)
Microfabrication Techniques
![Page 36: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/36.jpg)
Overview
![Page 37: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/37.jpg)
Overview • Micromachining technologies
• Bulk micromachining• Surface Micromachining
• Basic Processes• Lithography• Wet etching• Dry etching• Deposition
![Page 38: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/38.jpg)
UV-lithography • Lithography refers to a process whereby the
top layer on a wafer is selectively removed or patterned.
• Photolithography; light-stone-writing in greek
![Page 39: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/39.jpg)
UV-lithography
![Page 40: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/40.jpg)
Laser Sources
Wmin = k1 .
NA
![Page 41: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/41.jpg)
Types of UV-lithography
![Page 42: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/42.jpg)
UV-lithography
![Page 43: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/43.jpg)
UV-lithography • Mask making
• Resist spinning
• Alignment of wafer and mask
• Resist tone, Tg, critical dimensions
• Lithography resolution
• Depth of Focus
• Resist wall profile manipulation
• Clean-rooms, wafer cleaning
• Process sequence
![Page 44: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/44.jpg)
UV-lithography
• Resist applied to the surface using a spin-coating machine, which holds the wafer of a semiconductor, using a vacuum, and spins it at high-speed (3000-6000 rpm) for a period of 15-30 seconds.
• Preparation concluded by a pre-bake, where wafer is generally heated in a convection oven and then a hotplate to evaporate resist solvent
![Page 45: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/45.jpg)
Photoresist
![Page 46: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/46.jpg)
Developer
![Page 47: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/47.jpg)
Process
![Page 48: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/48.jpg)
UV-lithography
• Fiducals are patterns used for alignment on wafer steppers. These fiducials are located outside of the array or fields.
• Alignment of the mask is critical and must be achieved in the x-y plane
• Double alignment is especially important in the fabrication of micromachines
![Page 49: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/49.jpg)
Advanced Lithography
• Electron-beam lithography
• Ion beam lithography
• X-ray lithography
• Extreme UV-lithography
Wmin = k1 .
NA Reduce k1
Reduce
Increase NA
![Page 50: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/50.jpg)
![Page 51: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/51.jpg)
Advanced Lithography
![Page 52: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/52.jpg)
Advanced Lithography
Wavelengths started with the g-line (436 nm) of Hg - good down to 0.4m
Next came the 365nm i-line in the near-UV - this took us down to 0.3m
BUT no light bulb that emits enough intensity at wavelengths considerably smaller than 365nm
The solution was excimer lasers - 248nm, 194nm and 157nm (deep UV lithography)
this spelt …… the END of UV-lithography!
![Page 53: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/53.jpg)
Advanced Lithography
![Page 54: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/54.jpg)
Extreme UV Lithography
Technology breakthrough - 13.4nm wavelength of this light is more than 10 times shorter - allows patterning of lines below 50nm dimensions
Intel leading a consortium of six semiconductor companies called the EUV LLC to develop this technology
![Page 55: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/55.jpg)
Extreme UV Lithography: Sources
![Page 56: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/56.jpg)
Electron beam Lithography
Pattern directly written into resist by scanning e-beam
Eliminates the diffraction limits of optical lithography
Performance records:
- in PMMA (organic resist): 7nm
- in AlF3(inorganic resist): 2nm
![Page 57: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/57.jpg)
Optical Electron Beam
Advantage
Low ~High precision Fast exposure speed Relatively low cost
No diffraction Easy to control Available for small features
Disadvantage
Light diffraction Alignment problem Debris between mask and wafer
Needs vacuum High system cost Slow
UV vs E-beam Lithography
![Page 58: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/58.jpg)
Ion-beam Lithography• Variation of the electron-beam lithography technique - uses a focused ion beam instead of an electron beam
• The ions are field extracted from a liquid metal ion source (LMIS) that consists of a tungsten needle with a radius of curvature of 1mm that is wetted by a liquid metal.
• The application of an electric field (>108cm/V) to the wetted tip results in the formation of a cone with a radius of curvature of 10nm from which the ions are field extracted
• The extracted ions are accelerated, collimated and focused by a series of apertures and electrostatic lenses
• Spot-sizes of 10nm to 500nm are possible.
![Page 59: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/59.jpg)
Ion-beam Lithography
![Page 60: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/60.jpg)
X-ray Lithography
As shown in this figure, the penumbral blur, , on the adge of the resist image is given by:
= ag/L
a is the diameter of the x-ray source
g is the gap between mask and wafer
L is the distance from the source to the x-ray mask
![Page 61: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/61.jpg)
LIGA
![Page 62: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/62.jpg)
© M.J, Madou
LIGA
Allows the creation of 3-D structures with excellent tolerances and extremely high aspect ratios
Main drawback – very expensive to implement
![Page 63: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/63.jpg)
Soft LithographyTransfer of a self-assembled monolayer precursor with an elastomeric stamp onto a substrate
1) A master is generated by photolithography and a stamp is obtained by casting of an elastomer (PDMS etc.)
2) A pattern is generated by stamping a SAM on a substrate
![Page 64: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/64.jpg)
![Page 65: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/65.jpg)
Ink-jet micromachining
![Page 66: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/66.jpg)
Bulk, surface, DRIE
![Page 67: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/67.jpg)
Bulk micromachining • As the name implies, bulk micromachining
focuses on the creation of patterns or features within the bulk of some sort of starting material. In doing so, we rely on the physical structure of the material in question (amnogst other variables) to control the shape of these features
• Although materials such as quartz, pyrex, GaAs, Ge, etc. Are used as teh starting material for this technology, the material that is most commonly used is silicon
• Silicon has well understood lattice structure composed of two interpenetrating face-centered-cubic (FCC) lattices
![Page 68: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/68.jpg)
Silicon
![Page 69: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/69.jpg)
Miller Index
Miller Index are symbolic vector representations of the orientation of the atomic planes that make up the crystal lattice
![Page 70: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/70.jpg)
Miller Index
Greater density of atoms slower etch rates
![Page 71: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/71.jpg)
Silicon wafer
![Page 72: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/72.jpg)
• Silicon boules are grown using a seed material of known orientation. The boule is subsequently sliced into wafers that will have this same orientation.
• Silicon etchants and silicon wafer orientations are selected to create the necessary features within the bulk of the wafer.
Silicon wafer
![Page 73: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/73.jpg)
Bulk micromaching
![Page 74: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/74.jpg)
Bulk micromachining
![Page 75: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/75.jpg)
• Anisotropic etchants such as KOH:H2O (alkaline) tend to
etch different crystal planes at different rates, thus giving rise to structures having well defined sidewalls with precise and predictable angles of inclination (very little undercutting).
Anisotropic etchants
![Page 76: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/76.jpg)
Examples
![Page 77: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/77.jpg)
• Isotropic etchants such as mixtures of HF:HNO3:CH3COOH (acidic) tend to etch different crystal planes at the same rate, thus giving rise to rounded structures with much undercutting.
Isotropic etchants
![Page 78: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/78.jpg)
Isotropic etchants
![Page 79: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/79.jpg)
Wet isotropic etching
![Page 80: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/80.jpg)
Examples of etchants
![Page 81: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/81.jpg)
Examples of etchants
![Page 82: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/82.jpg)
Etch Stop
![Page 83: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/83.jpg)
Dry isotropic etching
![Page 84: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/84.jpg)
Dry anisotropic etching
![Page 85: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/85.jpg)
Deep reactive ion etching
![Page 86: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/86.jpg)
Deep reactive ion etching
![Page 87: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/87.jpg)
Surface micromachining • In the case of surface micromachining,a different
approach is taken in that rather than etching into the bulk of the starting material, structures are built up on the substrate surface
• These structures are created via the repetitive addition of layers selected for their various material properties, followed by the selective removal of these layers in a specific sequence.
• The vast array of materials that can be “deposited” includes polysilicon, silicon nitride, oxide, polyimide, metals, etc.
![Page 88: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/88.jpg)
Deposition
a) Chemical Vapor Deposition (CVD) systemsWhich rely on the chemical reaction of the constituents of a vapor phase at the substrate surface to deposit a solid film on this surface.
b) Physical Vapor Deposition (PVD) systemsWhich directly deposit the source material onto a given substrate in a “line-of-site impingement type deposition”.
Deposition systems may be divided into two groups:
![Page 89: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/89.jpg)
a) CVD: Common film types & sample chemistries
Polysilicon:
Silicon Nitride:
Silicon Dioxide:
Deposition
![Page 90: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/90.jpg)
DepositionTable 1. APCVD, LPCVD, and PECVD Comparisons CVD
ProcessAdvantages Disadvantages Applications
APCVD Simple, Fast Deposition,Low Temperature
Poor Step Coverage,Contamination
Low-temperature Oxides
LPCVD Excellent Purity,Excellent Uniformity,Good Step Coverage,Large Wafer Capacity
High Temperature,Slow Deposition
High-temperature Oxides, Silicon Nitride, Poly-Si, W, WSi2
PECVD Low Temperature,Good Step Coverage
Chemical and Particle Contamination
Low-temperature Insulators over Metals, Nitride Passivation
![Page 91: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/91.jpg)
Deposition
![Page 92: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/92.jpg)
b) Physical Vapor Deposition (PVD) systems
– In these types of thin film deposition systems, the source materials to be deposited take on a variety of forms:
• Solid• Liquid• Vapor
– In the case of PVD systems, the materials to be deposited are physically deposited using a variety of methods including:
• Thermal Evaporation • Sputtering• Etc. (Laser Ablation, Molecular Beam Epitaxy)
Deposition
![Page 93: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/93.jpg)
a) Physical Vapor Deposition (PVD) systems -
continued
– The range of materials that may be deposited using these methods include:
• Metals such as:
– Al – Cu– Au– Ag– etc.
• Compound & hard materials such as:
– Cr– TiN– CrN– AlCuSi– etc.
Deposition
![Page 94: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/94.jpg)
– The material to be deposited is placed in a crucible within a high-vacuum chamber.
– After the chamber is pumped down, the source is heated via (typically) resistive or e-beam heating. The material is heated to its boiling point such that it sublimates onto all exposed surfaces in the vacuum chamber.
– The amount of material deposited is controlled via a thickness monitor which is placed within the deposition chamber.
– The source material must be of high purity.
– Vacuum levels are on the order of 10-5 to 10-7 Torr.
Thermal Evaporation –
Resistive Heating
Thermal Evaporation –
e-Beam
Thermal Evaporation - General
Deposition
![Page 95: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/95.jpg)
Thermal Evaporation - drawbacks
– Resistive heating is the simplest method of evaporating metals such as Al
or Au, but it is also the “dirtiest” in that contaminants which find their way
onto the filament tend to be evaporated along with the metal.
– The purity issue can be addressed via e-beam evaporation since the
cooled, non-molten high-purity material to be deposited acts as a crucible
during the process (see schematic on previous slide).
– In the case of resistive heating, temperature uniformity across the filament
is difficult to control and therefore, evaporation uniformity onto the
substrates may be a problem. This is not an issue with e-beam
evaporation
– E-beam evaporation may cause surface damage due to ionizing radiation
and/or X-rays (@ voltages above 10kV, the incident electron beam will
give rise to X-ray emission).
Deposition
![Page 96: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/96.jpg)
Sputtering
Sputtering – principle of operation• A solid slab (ie., target) of the material to be deposited is placed in a
vacuum chamber along with the substrate on which the deposition is to
take place.
• The target is grounded.
• Argon gas is introduced into the chamber and ionized to a positive
charge.
• The Ar ions bombard the target and cause the target atoms to scatter,
with some of them landing on the substrate.
• The plasma is composed of the Ar atoms, Ar ions, the sputtered
material, gas atoms and electrons generated by the sputtering process.
• Allows the deposition of a large assortment of materials on any type of
substrate
Deposition
![Page 97: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/97.jpg)
Deposition: sputtering
![Page 98: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/98.jpg)
Sputtering – advantages/disadvantages
M.J. Madou
Deposition
![Page 99: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/99.jpg)
Surface micromachining
![Page 100: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/100.jpg)
Surface micromachining
![Page 101: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/101.jpg)
Surface micromachining
![Page 102: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/102.jpg)
Sealed cavity
![Page 103: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/103.jpg)
Examples
![Page 104: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/104.jpg)
Examples
![Page 105: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/105.jpg)
Bulk vs Surface
• Both bulk and surface micromachining concepts are most often combined to create both intricate and simple devices and systems.
• Other observations (M.J. Madou):
![Page 106: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/106.jpg)
Process Flow
![Page 107: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/107.jpg)
Process Flow
![Page 108: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/108.jpg)
Process Flow
![Page 109: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/109.jpg)
Process Flow
![Page 110: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/110.jpg)
Process Flow
![Page 111: TOPICS IN (NANO) BIOTECHNOLOGY Microfabrication techniques January 9th, 2007 PhD Course.](https://reader035.fdocuments.in/reader035/viewer/2022070408/56649e4f5503460f94b468f6/html5/thumbnails/111.jpg)
http://www.thoughtequity.com/video/clip/1659037_021.do