Surface Structure with High-Density Nanodots Formed by Pulse Nucleation Method Using Monomethylgermane

Nanodots were formed at a high density on a Si(001) substrate, which is misoriented toward [110] azimuth by 2°, by pulse nucleation using monomethylgermane (MMGe). This method involves alternating the substrate temperature between low and high temperatures. The surface reaction and nanodot formation were analyzed at an atomic level by scanning tunneling microscopy (STM) and reflection high-energy electron diffraction (RHEED). The STM analysis confirmed that uniform nanodots were successfully formed on the surface at a density of 1.3 ×1012 cm-2, and that they had an average diameter of 6 nm. The coexistence of both Ge and SiC nanodots was confirmed by RHEED when high-pressure reaction conditions were used.