Silicon's surface contains rows of paired atoms, each duo tilting slowly up and down like a seesaw. Theorists predict that these silicon pairs, or dimers, should be most reactive when other atoms or molecules catch them midway between a teeter and a totter, when the two silicon atoms are on an even plane. Subtle as this may seem, such details often become important for advancing semiconductor technology.
Now, researchers have for the first time created dimers that stay level while permitting scientists to study silicon-surface reactions in unprecedented detail. They've discovered that these level pairs are dramatically more reactive than rocking ones. Emily J. Buehler and John J. Boland of the University of North Carolina at Chapel Hill report the results in the Oct. 20 Science.