Sunny days tend to draw people outdoors, but this summer 63 undergraduates stayed inside clean rooms to learn the intricacies of nanoscale fabrication. The students, interns in the 2006 Research Experience for Undergraduates (REU) run by the National Nanotechnology Infrastructure Network (NNIN), presented their work Aug. 11 in the Duffield Hall atrium at Cornell.

Each summer the NNIN program pairs undergraduates with the Cornell NanoScale Science and Technology Facility (CNF) and 12 other national facilities. For 10 weeks, the interns learn to use state-of-the-art tools to perform research under the supervision of a mentor.

The program's practical approach appeals to many students, including Ravneet Bajwa, a junior at the University of California-Berkeley, who was one of 10 students who spent the summer at CNF.

"We studied transistors in classes but had no intuition on how they look," said Bajwa, who worked with Edwin Kan, associate professor of electrical and computer engineering at Cornell, to make memory devices.

Using a process called chemical mechanical planarization, Bajwa made polysilicon films just 15 nanometers thick (a nanometer is one-billionth of a meter, or about three times the diameter of an atom) for devices that might consume less power and write faster than the current flash memory technology.

"We have access to the tools so we can try out ideas right away," said Bajwa, who was impressed by the facilities and considers Cornell one of his top choices for graduate school.

Another intern, Nathan Henry, a double major in biomedical and electrical engineering at Michigan Technological University, also considers the NNIN REU experience a steppingstone to graduate school. Henry explored using a large electrical current to crystallize amorphous silicon. Such processes can lead to improvements in thin-film transistors that are ubiquitous in liquid crystal displays of cell phones and televisions.

Initially Henry tested the idea on nanoscale wires fabricated on silicon wafers that are a few inches wide. To study the wires, Henry used a scanning electron microscope that could view objects at over 50,000-fold magnification.

"Within this tiny area on the wafer, there were hundreds of metal pads and wires, and when we magnified it more, we began to see gaps and deformations," said Henry. "Every time we looked, I'd go 'wow.' It's incredible." He worked with postdoctoral researcher Ali Gokirmak and Sandip Tiwari, professor of electrical and computer engineering and the former director of CNF who is now director of NNIN.

Of the interns at CNF, five were Cornell undergraduates funded by the Intel Foundation. Erica Pratt, an Intel fellow, majors in mechanical and biomedical engineering at Carnegie Mellon University. In assistant professor of physics Itai Cohen's laboratory, Pratt looked at how small fluorescence-labeled particles, called colloids, would deposit onto patterned surfaces.

"I had to go outside of my area of specialty," said Pratt, who taught herself about solid-state physics and fluorescence microscopy.

Interns from all 12 campuses hosting the REU program gathered for the final presentation of slides and posters in Duffield. Among them were Cornell undergraduates Joseph D'Silva '09, an electrical and computer engineering major who worked this summer at the University of Texas-Austin, and Esha Mathew '07, a biological and environmental engineering major, who interned at Pennsylvania State University.

NNIN is funded by a cooperative agreement with the National Science Foundation as a national resource for nanoscience instrumentation.

Graduate student Alex Kwan is a science writer intern at the Cornell Chronicle.