Almaden Adventures

 

It was the first plane I had ever missed in my life. As I lay asleep at the gate the flight connecting me from LAX to San Jose left without me. What do you expect after a 12 hour flight from Auckland, a delayed plane, and an airport bar? Missing the plane wasn’t the worst thing to happen to me, arriving in LA without one of my bags took first place. Thankfully, after this my bad luck in California ran out and I was ready to get to work at the IBM Almaden Research Center. I was one of two lucky New Zealand students selected for the first IBM/MacDiarmid Institute studentships.

Don Eigler, the IBM fellow who first moved individual atoms with atomic precision, organised the studentship. I met Don in Christchurch a year or so previously when the university purchased a Blue Gene supercomputer. I got to show him around the labs on the 6th floor of the Physics building. Now I was in his territory and I would work with some world class equipment and phenomenal people.

The Almaden Research Center sits on top of 690 acres of undeveloped foothills just above Silicon Valley. It took me about 15 minutes to ride a bike up the hill to the lab. On the way I had many encounters with a variety of local wild life. Wild turkeys, rattle-snakes and deer roam the IBM hillside and I even had an encounter with a pack of coyotes who looked pretty hungry but weren’t quite fast enough to compete with gravity and a 10 speed.

I felt like a kid in a candy store as I walked through the research centre. There was lab after lab of complex equipment running important experiments. SEM’s, TEM’s, argon lasers, and pretty much any other diagnostic technique for material characterization can be found at Almaden along with the expertise necessary to fully utilise them.

I was selected for a project investigating the crystallization kinetics of a GeSb alloy for Bob Shelby. This alloy can exist in a metastable amorphous phase or a stable crystalline phase up to about 200oC. It can quickly and reversibly switch between the two phases depending on how hot it is made and how fast it cools down. The difference in electrical resistivity of the two phases is a way to achieve non volatile data storage with no moving parts. IBM’s prototype devices based on GeSb and other phase change materials are already smaller and faster than flash memory.

My task was to deposit the GeSb alloy by DC sputtering and perform a wide variety of laser annealing experiments along with AFM measurements. In these experiments the alloy was switched between the two structural phases by a variety of precisely controlled laser pulses. Elegantly named POET, the state-of-the-art laser annealing system monitors optical reflectivity and electrical resistivity in situ with nanosecond resolution. The data I gathered was then compared with a simulation developed by Geoffrey Burr. The results of this work should be published some time this year.

Working on this project was a real eye opener and I am very thankful for the opportunity. My ideas were listened to with respect by the excellent research group and I got a one hour seminar spot to talk about my thesis research to other groups. Overall, I learned more than I expected to in many areas and especially in making a career in science. I will never forget the experience and I hope more New Zealand students get a chance to work at IBM Almaden.