A growth method for creating arrays of atomically flat mesas on silicon

We describe a method for producing arrays of atomically flat mesa structure s on Si(111) through the deposition of Si on a lithographically patterned s ubstrate in the temperature range 750-850 degreesC. The Si source was a sup ersonic beam of Si2H6. With an appropriate choice of substrate temperature and deposition rate, the atomic steps initially present on each mesa surfac e move by a step flow process to the trenches, which define the mesa leavin g the surface as one extensive exposed atomic plane or terrace. The rate of clearing is believed to be limited by the velocity of step bunches. When t he terraces become sufficiently large, nucleation of stacks of monoatomic i slands occurs. Comparison is made with a previously developed evaporation m ethod for making step-free surfaces. (C) 2001 American Institute of Physics .