Note: all this stuff is a year or two out of date...
To see the formal résumé in PDF format, click here.
Having just finished my Ph.D. in electrical engineering at Arizona State University with an emphasis in solid state electronics, I'm temporarily at Purdue University in West Lafayette, Indiana where the bulk of the experimental work was done. I'm working on wrapping up some project details and writing several papers, which hopefully should start showing up in journals in the spring/summer. The dissertation is called Deep Ultraviolet Surface Inspection with Photoemission Enhancement.
The general area I work in, under Dr. Dan Hirleman, in is the inspection of micro and nano-structures for defects, which I've been doing since the mid 90s at ASU, where I also got my MS in EE.
Briefly, the main pertinent problems in this area are in semiconductor manufacturing, in which, as you may know, integrated circuits are fabricated with millions of individual parts. These parts may have individual dimensions as small as 130 nm in current processes, which, to give you some idea of the scale, is around 1/20 the diameter of a smallish bacterium. Now you can figure if the part is that small, it has to be constructed even more precisely. Fortunately, these are electronic parts, so often deviations in the manufacturing as large as 1/3 of that dimension, say about 40 nm, can usually be tolerated. However, that still leaves us in a position where we need to find defects as small as 40 nm across. Even worse, as manufacturers try to make things even smaller, our defect tolerance goes down. In a few years, we'll probably need to see defects as small as 20 nm!
You can figure in a material like silicon, this is roughly the same size as a ball with a diameter of about 400 atoms, and in some instances we will even need to detect deviations of a dozen layers of atoms.
Obviously, this is rather challenging, and an aspect of the problem not often appreciated is that not only do you have to be able to see such small defects, you also have to be able to inspect millions of structures just like it, and you need to be able to do it all before the sun burns out.
There are in fact numerous techniques which can see or at least detect deviations that small and even smaller, such as electron microscopy, atomic force microscopy, and near field scanning microscopy, however they are all horribly slow and quite delicate.
Currently, the best methods, combining speed with sensitivity, employ optical techniques, either taking high magnification pictures or scanning laser beams across the surface and monitoring light which is indirectly reflected (or scattered) by structures on the surface. However, the former technique runs up against a fundamental physical limit to the resolution, or ability to show detail, that relates to the wavelength or color of the light. Some things are simply to small to form distinct images with normal light. The latter technique doesn't have a clear limit to the minimum size of defect it can detect, but the data acquired from scanning scattering inspection are much more difficult to interpret, especially for complex structures. The resolution of this technique is also in some respects limited by the size of the laser beam spot on the surface, which is in turn limited by the same factors that limit imaging resolution. Practically, wafers with complex structures in the later manufacturing stages are inspected by imaging techniques while wafers in the early stages of the process are more easily inspected by scanning scattering.
My MS thesis, "A model for the performance of surface-scanning inspection systems," gives the results of a project funded by SEMATECH which investigated the random processes which control the tradeoff between speed and detectability for wafer inspection. This work was then used under a contract with the Semiconductor Research Corporation (SRC) as a framework to analyze possible techniques for defect detection in 70 nm processes (about half the size of current state-of-the-art processes), some of which results appear in the open literature in the proceedings of the 1998 SPIE conference Flatness, Roughness, and Discrete Defect Characterization for Computer Disks, Wafers, and Flat Panel Displays II in a paper titled "Surface particle detection for the 0.07 μm generation and beyond."
That work identified extensions of optical techniques into the ultraviolet wavelengths and electron-beam techniques as being most likely to enable detection of the relevant defects, and in 1999 we received a second SRC contract to pursue a project aimed at investigating these ultraviolet extensions of optical techniques, along with some novel approaches, details of which are currently in the process of being published, though they are currently (and have been) accessible to SRC member companies on the SRC website.
Unlike the previous two projects, this new investigation involved a great deal of laboratory work including the construction of a sophisticated deep/vacuum ultraviolet scatterometer, which is discussed in detail on the group website. It was at the beginning of this project when I moved to Purdue along with approximately half of the ASU research group.
Of course, between and beside my own projects, I've also spent quite a bit of time working on general lab tasks and assisting fellow students with their projects, giving seemingly innumerable tours and presentations, and doing periodic summer internships in industry, at Mannesmann-Demag (in Systemsverwaltung, systems administration, at the Duisburg, Germany facility), Tencor (now part of KLA-Tencor), and Advanced Micro Devices (AMD, the other microprocessor company). All three internships, by the way, were fantastic experiences, and I highly recommend them for any engineering graduate students.
Besides, the three major projects noted, I did a lot of informal systems administration for our lab, the usual mix of setting up printers, hunting viruses, and developing solutions for our often rather peculiar computing needs. Being an ex-programmer (and still sometimes not so ex-), I also found my software expertise frequently sought after for such odd jobs as developing exception handlers, device drivers, and front ends for some of our simulation software. The biggest of the side projects though was completing and bringing on line our new scatterometer at ASU, which had been delayed for over a year by a host of daunting technical problems and the relentless personnel turnover that often dogs long-term university research. In addition to this, I also (somehow) managed to find time to work on a novel computational model for photon recycling in semiconductors (yes, I do actually get to do solid state sometimes!) under the guidance of one of my professors (and frequent committee member) Ron Roedel. Unfortunately, I've had quite a bit of trouble finding a journal where the reviewer thinks the topic is appropriate, since it falls in an uncomfortable niche between applied physics and numerical analysis (physics journals say it leans too far to the math side and math journals say it leans too far to the physics side), but eventually I'll get the time to reformat it and shop it around to some other venues.
Oh, yeah, and while I was doing that I did 54 credit hours of hard time in graduate engineering, physics, and materials science classes, including nuclear physics, semiconductor devices (2 sem.), optoelectronics (2 sem.), heterostructures, random signal theory, statistical pattern recognition, transmission electron microscopy, solid state theory, semiconductor characterization (with Dieter Schroder, who wrote vol. VII of the renowned Modular Series on Solid State Devices), transport theory (with David Ferry), coherent optics, semiconductor processing, electromagnetics, and analog and digital circuit design, not to mention all the undergrad EE courses I had to take because my BS is in physics, circuits, circuits, and more circuits, power electronics, signals, and all those lovely microprocessor courses that I blithely sailed through. I also managed to pick up 3 more semesters of German, 2 of Chinese, and 1 of Old Norse along the way, as well as a curious class called "German Film." Another highlight was the opportunity to take an intro class in human origins from Donald Johanson, the paleoanthropologist who discovered "Lucy" in the early 70s.
Here at Purdue I've also been deeply involved in developing and contributing to projects involving the novel use of light scattering for biosensors with funding by the USDA and US Navy, the results of which are yet to be published, pending their completion.
Life before ASU included a brief stab at graduate school in physics at the University of Oklahoma, which I enjoyed immensely and would have been really great if I'd made less stupid decisions about how many graduate physics courses to take. Important lesson learned: graduate school is very, very different from undergrad - don't overdo it the first semester.
Prior to that educational experience, I worked for about a year in 1991 as a PC programmer for the Kurta Corporation (long since absorbed by Mutoh) in Phoenix, AZ, where I learned a lot and met a number of really cool people. It was also my first encounter with Engineering Cubicle Culture. Kurta made digitizers, which are high-accuracy pointing devices with tablets, mainly used in drafting and graphic arts, and I was basically the only in-house software developer, working on the support software, the drivers, the installer software (this was in the benighted times before InstallShield). The other curious feature of the position was that I had, at least originally, been hired primarily to localize the existing software for foreign markets, which goes to show that foreign language education really is bankable. Apparently, they had trouble finding C programmers who were at least familiar with German, Italian, Spanish, and French, so they were quite happy to hire a recent physics/math grad who'd only learned C programming a month earlier. After returning to Phoenix and starting at ASU, I did some consulting for Kurta off and on for a year or two, up until about the time when I got my research assistantship in Dr. Hirleman's group.
Finally, I should mention my undergraduate days at Morehead State University in scenic Eastern Kentucky, where I did a bachelor of science in physics and mathematics, with a minor in chemistry and the honors-program stamp (1990). Morehead, in a county that still prohibited alcohol until 1985, is strangely where I first encountered chat rooms (1989), the net (1988), and email (1986). The net and email have certainly changed character, though I can't really say as much for chat rooms. Morehead is a unique place; it really does have some dedicated faculty, and you'll never find yourself lost in a sea of anonymous freshmen as may happen in classes at many other schools of the Enormous State University variety. It's a very personal place. OK, maybe it's not Harvard, but you can get a solid education there, and you won't be in debt for the rest of your life after you get out, especially if you can snag one of those delicious full-ride scholarships like I did. At one time, and this may still be the case, National Merit Finalists could get a full 4 years without paying a dime.
And a list of assorted skills, some of which I touch on in some versions of the résumé:
