CAREER: In Situ Monitoring of Surface Phenomena during Silicon Germanium Deposition and Etching

University Of New Mexico, Albuquerque NM

Investigators

Abstract

This CAREER project centers on nanoheteroepitaxy of SiGe on Si for future optoelectronic applications. Integrating nanostructure architectures into manufacturing poses numerous engineering challenges such as selective deposition of SiGe on Si and ideal pattern transfer with minimal critical dimensional loss. The strategy here is to understand fundamentally interfacial phenomena occurring on SiGe surfaces. The approach utilizes in situ real time infrared and Raman spectroscopic techniques. The real time diagnostics provide a means to capture the dynamic SiGe surface response to deposition and etch precursors. In this regard, the detection sensitivity and the polarization dependence of attenuated-total-reflection Fourier transform infrared spectroscopy and attenuated-total-reflection surface enhanced Raman spectroscopy will be exploited. The two techniques will help distinguish sidewall surface phenomena from trench bottom phenomena during plasma etching of SiGe. It is also intended to extract the ion energy distribution function in etch plasmas from experimentally measured time-varying plasma and substrate potentials. Capacitive divider and Langmuir probes can measure these potentials. The distribution functions will be correlated to resulting etch profiles. The salient information gained from the comprehensive diagnostics is expected to bring improved understanding of deposition and etching mechanisms of SiGe as well as ion/neutral transport inside the SiGe trenches. The knowledge gained will also facilitate ideal pattern transfer, help realize novel applications of SiGe, and guide development of computational profile simulators. Three educational activities will be pursued: (1) develop new elective courses in semiconductor processing, (2) provide close mentorship and career counseling through research, and (3) initiate a high school outreach program. These educational activities will draw strongly from the research. Courses in chemical vapor deposition and plasma/surface diagnostics will be developed to provide students alternate venues to prepare for a career in the electronics industry or related research fields. In addition to graduate students, undergraduate students will actively be involved in the research. High school seniors will be aggressively recruited using the outreach program to inform prospective high school students of the research-oriented educational opportunities at UNM. The outreach program additionally serves to improve the percentage of high school students pursuing post-secondary education and particularly to increase the enrollment of Hispanic-descent students. The latter goal meets an institutional interest of UNM, a federally recognized Hispanic-serving institution. %%% The project addresses fundamental research issues in a topical area of materials science having high technological relevance. The scope of the project will expose students to challenges in materials synthesis, processing, and characterization. An important feature of the project is the strong emphasis on education, and the integration of research and education. ***