9508637 Ganz A recently developed high speed scanning tunneling microscope (STM) will be used to study chemical vapor deposition (CVD) growth and diffusion processes on silicon surfaces in ultrahigh vacuum (UHV). The surfaces will be imaged with atomic resolution in situ before, during, and after growth at temperatures ranging from room temperature to 800 K. This instrument operates roughly 30 times faster than conventional instruments, at scan rates up to 100,000 /s which allows the study of CVD processes with atomic resolution on time scales down to 10 ms. The project will address three general aspects of Al CVD on silicon: the growth of Al using the precursor, dimethylethylamine alane (DMEAA); surface mass diffusion of the deposited material; and selective area growth of Al on clean and patterned silicon surfaces. The selectivity of growth will be tested on clean surfaces with small metal islands, and also using features drawn into a monohydride resist layer. The ability to remove hydrogen, atom by atom, from hydrogenated silicon surfaces using the STM tip coupled with selective growth of Al on unexposed areas allows basic studies of nanoscale fabrication, in addition to the investigation of fundamental nucleation and growth phenomena associated with CVD. %%% A high speed scanning tunneling microscope (STM) has recently been developed and will be used for basic research studies of the growth and diffusion of aluminum on silicon, a process important to the fabrication of advanced microelectronic devices and circuits. The ultrafast STM technology will be studied further as part of the research, and tested for possible use in the definition and delineation of ultrafine device and circuit patterns. This technology is also being considered for applications in the fabrication of high density memory media. Additionally, an important feature of the program is the training of graduate and undergraduate students in a fundamentally and technologically significant area. The knowledge and und erstanding gained from this research project is expected to contribute generally to improving the performance of existing, and the creation of new, more advanced devices used in computing, information storage and processing, and telecommunications. ***
