Nano- ve Mikro-Teknoloji MEMS Mikro-Elektro-Mekanik Sistemler Doç. Dr. Levent TRABZON Ölçeklendirme MEMS are systems that integrate • • • • • • Sensing Actuation Computation Control Communication Power • • • • Smaller More funtional Faster Less power consuming • cheaper Just One Application Domain 2007 Mercedes Bug Passive Drag Reduction Laser machined riblets A340 flight tests Advanced Technology Centres - Sowerby Commercialized MicroSystem Product Mass commercial application: Acceleration Sensors Elastic hinge Analog Devices' ADXL50 accelerometer Surface micromachining capacitive sensor 2.5 x 2.5 mm die incl. electronic controls Proof Mass Spacer Force Silicon substrate Capacitive Accelerometer Cost: $30 vs ~$300 bulk sensor (‘93) Cut to $5/axis by 1998 Replaced by 3-axis ADXL150 “Every new car sold has micromachined sensors on-board. They range from MAP (Manifold Absolute Pressure) engine sensors, accelerometers for active suspension systems, automatic door locks, and antilock braking and airbag systems. The field is also widening considerably in other markets. Micromachined accelerometer sensors are now being used in seismic recording, machine monitoring, and diagnostic systems - or basically any application where gravity, shock, and vibration are factors.” http://www.analog.com/library/techArticles/mems/xlbckgdr4.html Intelligent Textile Infineon Commercialized CMOS based MOEMS (Photonic MicroSystem) Portable elctronics Home entertainment Video Walls Digital Camera Next generation lithography Optical switches … Micro Needles/Probes (kumetrix.com) These needles/probes penetrate human skin reliably and painlessly, and can be used in instruments for single-use or continuous monitoring of analytes in blood. Glucose self-testing by diabetics Resembling:mosquito But, mosquita uses chemicals to induce painless blood emisson. With micro needles, no chemical is used. Under development. MEMS Fabrication Technology IC Processes Micromachining Photolithography Bulk Oxidation Diffusion Ion implantation Bonding Surface Deposition Etching Metallization Micro-molding MSL LITHOGRAPHY Evaluation Spin Casting of Resist Spinner Types of Lithography And Projection Lithography E-Demeti Lithography Applications Raith best picture award 2005 Applications Raith best picture award 2006 Applications – Physics Al-nanobridge used as a tunneling contact (after mechanical break) M. Goffman, CEA Saclay, France E. Scheer, University of Konstanz, Germany SOFT LITHOGRAPHY MicroContact Printing Feature size as small as 300nm Patterned SAMs can be used as resist in selective etching as low as 30 nm feature sizes Samples by microcontact Hot Embossing By Hot Embossing SU resist • Cheap way of doing high aspect ratios (>20) • High resolution negative resist • Near UV high vertical walls • After development, thermally and chemically stable, due to cross-linking • Biocompatible HARMST (High Aspect Ratio Micro System Technology LIGA • LIGA developed at the Karlsruhe Nuclear Research Center in Germany in 1986 • LIGA: Lithografie, Galvanik, and Abformung (Lithography, Electroforming and Injection Molding) • It uses high energy, low divergence X-Rays produced by synchrotron source • Upto 1000 micron deep penetration thorugh resist via 0.2 nm wavelenght X-Ray • With λ~0.7 nm, 400 µm structural height by four times irridating on PMMA, but λ~0.2 nm, 500 µm structural height by a single shot • Effect of diffraction and secondary electrons are up by lower λ • Be mask membrane and Au as absorbing material LIGA • Use of PMMA – Long exposure (cost) • A new alternative: a novolak resin, hexa(methoxymethyl) melamine as crosslinker and tetrachlorbisphenol A as acid generator. – no swelling and dark erosion during development – Extremely smooth side walls with surface roughnesses less than 20 nm – stable in most standard electroplating baths, e.g. for gold, nickel and nickel-iron alloys Electroforming Materials Additive, high height, co-deposition and smooth surfaces LIGA + Electro Discharge Machining Ceramic Structures by Powder Technology + LIGA MicroStereoLithography Scanning MSL Projection MSL Built microparts in line by line fashion Built one layer at one exposure MSL Comparison of MSL and SL Viscosity of monomer has crucial importance Surface tension effect in microscale hinders efficient filling and flat surface formation Classical MSL • Beam-focusing improvement is necessary for microfabrication with higher resolution • Too many mobile optical elements poor focusing • Motion of the laser beam a portion of the surface of a sphere defocusing • Prevents high resolution fabrication •Fast fabrication speed industry Integrated Hardened MSL • Using a movable stage instead of movable mirrors smaller focus spot, higher-fabrication resolution • Focus point is fixed, no need to dynamic focus lens Dynamic Mask Projection MSL • Uses a dynamic mask generator allows the fabrication of a complete layer by one exposure only and leads to a quick fabrication of complex 3D microobjects. • The irradiation beam is shaped with a computercontrolled liquid-display (LCD) as a dynamic mask generator. Examples on Dynamic Mask Projection PVD (FBB) FIB MBE ICP-RIE ORNEK Film Properties Morphology PVD ile İTÜ’de Yapılan NANOçalışmalar Matcsticks Zigzags Spiral C-Shaped Mechanism Low Adatom Mobility and Atomic SelfSelf-Shadowing 20 to 80 % porosity Column width: 30 –100 nm ZONE-M without Ion Bombardment Experimental Set-up for STF Feedthrough Cooling Cu Tubes For stepper motor Substrate holder, Si wafer Angle adjustment plate Evaporation boat, and current cables Experimental Set-up II Control Screen Cold water inlet Power Transformer Microprosessor Stepper motos Cables Nano-Sized Engineered Thin Film Porous NiTi 57˚ NiTi thin film by Magnetron Sputtering (a.u) 600 C Annealing 450 C Annealing 57 Substrate is 85o against surface source. No Annealing The columns are smaller than 100 nm 20 30 40 50 60 ˚ 70 80 2θ, Derece 90 100 110 120 Different Materials Top View Cross Section View Ruthenium Top View Cross Section View Tungsten Different Materials Top View Cross Section View Platinum At the present time, tissue-characterization is on the way at ITU-MOBGAM Osteoblast tests: MTT, NBT-BCIP, Griess Test...