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Lurie Nanofabrication Facility, February 28, 2012

Room 1303, EECS Building,  at 8:00 am. University of Michigan North Campus

Registration Click Here

Speaker Bios:

Brian VanderElzen:

Brian VanderElzen is the Associate Director of the Pattern Group at the Lurie Nanofabrication Facility – University of Michigan.  He has been responsible for etch tool specification and etch process development at the LNF for the past 10 years.  In his current role, he is now similarly involved in lithography hardware and processes.  Brian received his BSE in Materials Science and Engineering from the University of Michigan in 1993.

Dr. Stephen Vargo

Dr. Stephen Vargo received his Ph.D. from the University of Southern California in Aerospace Engineering Department in 2000. He conducted his Ph.D. research on a novel micromachined vacuum pump known as the Knudsen Pump specifically targeted for aerospace and compact applications. Dr. Vargo then joined NASA’s Jet Propulsion Lab in the Microdevices Laboratory working on a variety of MEMS and space applications as a key member of the technical staff. From 2001 to 2006, he was a process development engineer and later MEMS manufacturing engineering manager at a MEMS startup company focused on the emerging optical telecom field. Since 2006, Dr. Vargo has been the Applications Manager for SPTS leading customer system installations, applications and process support with his team that supports the North America region. He has extensive experiences in DRIE and has worked in the MEMS field for over 15 years.

Dr. Pran Mukherjee

Pran Mukherjee is a Research Scientist in the Space Nanotechnology Laboratory. Dr. Mukherjee received a B.S.E. in Electrical Engineering from the University of Michigan in 1996. He spent the next seven years working on large-scale software engineering projects including a battlefield-scale target designator using synthetic aperture radar, vehicle passenger detection for airbag deployment, an immersive 3D jetski simulator for the Coast Guard, and others. In 2004 he was the first student to graduate from the University of Michigan’s new Masters of Engineering program in Integrated Microsystems. He went on to complete his M.S. (’05) and Ph.D. (’08) in Space and Atmospheric Science under Dr. Thomas Zurbuchen in the Solar-Heliospheric Research Group. He won two prestigious NASA Graduate Student Research Program grants as primary funding for the work, as well as an ancillary grant for laboratory funding.

Dr. Mukherjee’s current research at MIT is an extension and amplification of his graduate work. He has achieved record-breaking geometries for his silicon nanogratings, nearly tripling the results obtained during his PhD research. These new gratings will be the key element of the Critical-Angle Transmission Grating Spectrometer, an X-ray diffraction instrument on the International X-ray Observatory. In addition, he designed a process for an industrial study of quantum-dot enhanced solar cells on glass, created a technique to enable efficient cooling during the etching of thin membrane silicon devices, and has shouldered some of the duties of lab management for the SNL. He is also assisting in the guidance of graduate students both at MIT and at the University of Michigan.

Dr. Jianping Fu

Dr. Jianping Fu is currently an assistant professor of Mechanical and Biomedical Engineering at the University of Michigan, Ann Arbor.  He received a B.S. degree (2000) from the University of Science and Technology of China (USTC) and a M.S. degree (2002) from the University of California at Los Angeles (UCLA), both in Mechanical Engineering.  He earned his Ph.D. degree in Mechanical Engineering from the Massachusetts Institute of Technology (MIT) in 2007, with a major of biological engineering and a minor of micro/nanomechanics and engineering.  Dr. Fu was an American Heart Association postdoctoral fellow in the Department of Bioengineering at the University of Pennsylvania from 2007 to 2009.  Dr. Fu’s current research interests focus on BioMEMS/NEMS, mechanobiology, stem cell biology, and applying microfabrication technology to illuminate biological systems, at both the molecular and cellular levels.

Dr. Jae Yoong Cho

Dr. Jae Yoong Cho received B.S.E. in Electrical Engineering and Materials Science and Engineering in 2004 and M.S. and Ph.D. in Electrical Engineering in 2007 and 2012, respectively, all from the University of Michigan.  His Ph.D. research topics include the development of high-performance MEMS rate- and rate-integrating gyroscopes and MEMS micropackaging.  He will continue his research in the related fields as a postdoctoral researcher.

Lecture Abstracts:

Lecture #1: Introduction about DRIE and recent process developments

Since the introduction of the Bosch Process nearly 20 years ago, RIE as a machining mechanism for silicon has been a prime enabler of MEMS technology. Over those years, the drive has been for faster, deeper, higher aspect ratio etches. Silicon etching has received much attention and seen many improvements over that time. Have the limits been reached?

Though silicon has many great properties, in recent years researchers have sought other materials more specifically suited to the particular needs of their intended devices. Are there viable etches for these other materials that will allow them to be used as structural materials in three dimensional devices? Will they be cost effective enough to be industrially useful?

It is the objective of this talk to provide useful information to help ascertain the answer to these questions as well as to provide insight into, and some solutions for, common hurdles and pit-falls associated with deep, high aspect ratio etching.

Lecture # 2: Update on SPTS DRIE

SPTS will present a summary of the DRIE technology it offers for the MEMS and Advanced Packaging markets.  SPTS is the leading provider of this technology and the examples shown will describe the latest capability for etching structures in Si for a variety of end applications. A special focus will be placed on HAR applications and some of the unique, industry-leading features to fully enable them.  Alongside this, the techniques and methods available for expanding the process envelopes for Si DRIE will be presented including a unique endpoint technology for low open area patterns.

Lecture # 3: DRIE at the nanoscale: a whole different world

Performing DRIE on dense arrays of nanoscale features produces a set of challenges that are far more pressing than they are for more standard processes.  Perhaps the most urgent problem is that of sidewall flatness and verticality, but other issues include mask undercut, localized plasma loading, and feature support.  We have reported trench aspect ratios of 60:1 for 100 nm half-pitch gratings, and have recently demonstrated that we can stop that etch cleanly on a buried oxide layer and then perform a KOH polish of the grating lines.  This required some innovative alignment, and the etching would not have been possible without the STS Pegasus tool.

Lecture # 4: Synthetic micro/nanosystems for rapid biomolecule analysis and stem cell research

Synthetic micro/nanoscale systems are emerging as powerful high throughput tools for quantitative analysis of molecular and cellular functions.  In this talk, I will present different examples of micro/nanoscale systems fabricated using deep reactive ion etching (DRIE), for either rapid analysis of biomolecules (such as DNA and proteins) or directed differentiation of adult human stem cells.  First, I will describe a new class of nanofluidic filter array devices and their implementation as controllable molecular sieves for both analytical and preparative separations of DNA and proteins.  Second, I will describe a microscale system comprised of a novel set of microfabricated extracellular matrices (ECM) that can uncouple changes in matrix rigidity from other properties of the matrix (e.g. adhesive ligand, adhesion area).  Using this microfabricated synthetic ECM system, we have implicated matrix rigidity as a critical mechanical signal that can regulate stem cell adhesion, cytoskeleton assembly / contractility, cell spreading, and proliferation.  Furthermore, we have found that matrix rigidity can switch the differentiation potential of mesenchymal stem cells between osteogenic and adipogenic fates.

Lecture # 5: DRIE of single-crystal silicon for MEMS inertial sensors

Deep Reactive Ion Etching (DRIE) of single-crystal-silicon (SCS) is needed to form microelectromechanical systems (MEMS) from bulk silicon or silicon-on-insulator. In this talk we will discuss DRIE requirements for silicon-based inertial MEMS sensors, and will describe our recent work in several areas: (1) Deep (>100 um), narrow (< 5um) trenches with straight and smooth sidewalls are needed to form capacitive gaps for electrostatic actuation or sensing. (2) DRIE etch lag, in which wide and narrow trenches etch to different depths, is normally considered a process challenge but if this phenomena is well-controlled, etch lag can be exploited to form complex device geometries. (3) DRIE-last processes are often needed for device release, but it can be challenging to obtain clean and uniform etching over existing features. (4) DRIE etching requires good thermal contact to the etched substrate, which can be a challenge for silicon-on-glass MEMS architectures. These process developments will be described in the context of our work on a new MEMS gyroscope called the Cylindrical Rate Integrated Gyroscope (CING).

Maps and Directions:

Floor Plan for EECS

http://www.eecs.umich.edu/eecs/visitors/EECSmap.pdf

Link for map of EECS location and North Campus parking

http://pts.umich.edu/maps/north_medical.pdf

The Building address is:

1301 Beal Avenue, Ann Arbor, MI 48109.

Parking is available on North Campus at any of “Red” visitors parking lots, this will need payment by cash or credit card for the full duration of your intended stay. Coffee and registration are inside the Electrical Engineering and Computer Science Building (EECS Building) at room number 1303.  Starting at 8.00 am. Note, if you park at NC48 lot there is an external  pathway/stairs  between Computer Science building and Dow building which will bring you close to the front door of EECS.For more information:

Contact David Yates at LNF-info@umich.edu or 734-323-1432

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