0507351_Ludwig

1. Time-Resolved X-ray Studies of Low-Energy Ion Bombardment and Plasma ProcessingKarl Ludwig, Boston University, DMR 0507351 We are using intense x-rays from the National Synchrotron Light Source (NSLS) to examine how atoms on the surface of materials move during ion bombardment and plasma processing. These are important processes in the development of semiconductor devices. X-ray scattering allows us to examine nanoscale structures on the surface as they spontaneously form. Real-time grazing-incidence small-angle x-ray scattering (top) shows the growth of a peak due to the formation of nanodots on a silicon surface during ion bombardment with seeding. Comparison of the time evolution of the x-ray scattering with theoretical predictions (lines) allows us examine fundamental mechanisms causing the behavior. The bottom figure shows the resulting nanodots.

2. Time-Resolved X-ray Studies of Low-Energy Ion Bombardment and Plasma ProcessingKarl Ludwig, Boston University, DMR-0507351 Three graduate students (Gözde Ozaydin, Yiyi Wang and Eitan Anzenberg) and two undergraduates (Safa Alzaim and Genelle Pugliese) have been contributing to the project. Gözde and Yiyi graduated with their Ph.D. during the past year. During Summer 2007, we also introduced a student in the Boston University High School Honors Summer Research Internship Program, Dylan Rankin, to materials research. Although he has now returned to high school, Ryan is continuing to discuss the possibility of performing further experiments on pre-stressed wafers with us. He plans to go on to major in Physics in college. High school student Dylan Rankin points to results on his poster describing the work that he did in our laboratory. Dylan, a participant in the Boston University High School Honors Program, measured the stress evolution of Si wafers during ion bombardment to better learn how stress development might be related to nanostructure formation.