Understanding Lateral Tunneling Understanding Lateral Tunneling - PowerPoint PPT Presentation

Understanding Lateral Tunneling Understanding Lateral Tunneling Accelerometer and The Micromachining Accelerometer and The Micromachining Process Process Alma Garc Garcí ía a Alma Architectural Engineering Architectural Engineering Allan Hancock College Allan Hancock College Mentor: Laura Oropeza Mentor: Laura Oropeza Advisor: Kimberly Turner Advisor: Kimberly Turner Sponsor: Institute for Collaborative Biotechnologies Sponsor: Institute for Collaborative Biotechnologies

Outline Presentation Outline Presentation � Project and Goals Project and Goals � � Introduction Introduction � � Types of Accelerometers Types of Accelerometers � � Micro Fabrication Process Micro Fabrication Process � � Actual Pictures Actual Pictures � � Experimental Testing Experimental Testing � � Results Results � � Summary Summary � � Future plans Future plans �

Project Goals Project Goals � Getting familiar with MEMS principles Getting familiar with MEMS principles � � Characterization of different configurations of lateral tunnelin Characterization of different configurations of lateral tunneling g � accelerometers by interferometer technique accelerometers by interferometer technique � Understanding the physics of the quantum mechanics phenomena Understanding the physics of the quantum mechanics phenomena � of “ of “tunneling current tunneling current” ” and the importance of using it in ultra high and the importance of using it in ultra high sensitive devices sensitive devices � Overview of MEMS fabrication process: SOI PROCESS Overview of MEMS fabrication process: SOI PROCESS �

Introduction Introduction � What is MEMS? What is MEMS? � What is an accelerometer? What is an accelerometer? � � Micro Electro Mechanical Systems A sensor that detects A sensor that detects changes on velocity changes on velocity Applications � Applications � • Seismology Seismology • • Air bag deployment Air bag deployment • • Aerospace Aerospace • Courtesy of Sandia National Laboratories

One possible application I wish I had an air-bag deployment in my car!

Two Types Of Lateral Tunneling Accelerometer • Design 1 Mass~7.08e -10 [Kg] 120µm 80µm F V Top view 300µm • Sensor • Actuator 1 Gold Tunneling Tip * Parallel plates X~10A° e e e F V V Tunneling 100mV

• Design 2 • Sensor * Tunneling Tip Gold comb-drive Top view actuator X~10A° Poof-mass proof-mass e e e I t V Tunneling 100mV springs • Actuator 2 [nA] * Interdigitated Comb-Fingers V [Å] Ultra high sensitive! V

SOI Fabrication Process Remove Photo Resist SOI wafer 1 5 Photo Resist Release Structure 6 2 Lithography Metal Deposition 7 3 Deep Etching Photo Resist 4 Silicon Silicon Oxide (SiO 2 ) Gold

Mirror

Equipment for testing Monitor Laser Vibrometer Function Generator MEMS Oscilloscope Atmospheric Package Holder Joystick Vector Analyzer

Frequency Response Analysis A max V in=Asin(wt) Device W o Sweeping Vel X’ V in =Asin(w 0 t) t Device Disp X t

Results Large Lateral Tunneling Accelerometer Di spl acem ent at f =3822 and Vsqr t =5 1. 4 A max A max 20 1. 2 18 1 16 /s] [ u m] m 14 0. 8 plitude [m 12 0. 6 10 Di s p l 0. 4 8 6 0. 2 m A 4 W o = natural frequency 0 2 0 -0. 2 0 500 1000 1500 2000 0 500 1000 1500 2000 2500 Frequency [Hz] Ti m e [ s] Fix-Fix Lateral Tunneling Accelerometer soi - 17 FFTA 5 Fr equency R esponse 5 4. 5 4 ] /s m 3. 5 [m 3 ity 2. 5 2 c lo 1. 5 V=5 e V 1 V=4 0. 5 0 0 500 1000 1500 2000 Fr equency [ H z]

Summary � Getting familiar with MEMS Getting familiar with MEMS � � Understand Micromachining Understand Micromachining � process process � Understand the dynamical Understand the dynamical � parameter of lateral tunneling parameter of lateral tunneling accelerometer accelerometer � Work with High Work with High- -Tech Tech � equipment equipment � Visit clean room Visit clean room � � Visit the FIB room Visit the FIB room � � Learn about the life of grad students Learn about the life of grad students � THE MOST EXCITING activity: participating in the micro- -fabrication fabrication � THE MOST EXCITING activity: participating in the micro � of lateral tunneling accelerometer and their characterization! of lateral tunneling accelerometer and their characterization!

Acknowledgements � Mentor: Laura Oropeza Mentor: Laura Oropeza � � Advisor: Kimberly Turner Advisor: Kimberly Turner � � People at Turner Lab People at Turner Lab � � INSET: Trevor INSET: Trevor Hirst Hirst, Dr. Arnold, Liu , Dr. Arnold, Liu- - � Yen kramer Yen kramer, Mike Northern , Mike Northern � AHC: Julie Niles, O AHC: Julie Niles, O’ ’Connor, Mrs. Connor, Mrs. � Wong Wong � CNSI CNSI � � UCSB UCSB � � ICB ICB �