화학공학소재연구정보센터
Langmuir, Vol.20, No.11, 4604-4608, 2004
Temperature dependence of formation of nanorods and dots of iodine compounds on an H-terminated Si(111) surface in a concentrated HI solution
Immersion of atomically flat, H-terminated Si(111) surfaces in 7.6 M HI for 0.5-4h caused spontaneous formation of nanosized clusters at the Si surface. X-ray photoelectron spectroscopy analysis suggested that the clusters were composed of silicon iodides (such as SiHxI4-x), produced most probably by Si etching with HI. Atomic force microscopy inspection revealed that the immersion at a low temperature below about 30 degreesC led to the formation of long rod-shaped clusters, oriented in the <(1) over bar(1) over bar2> direction or equivalents, whereas the immersion at a high temperature above 30 degreesC led to the formation of circular dot clusters, their size and shape changing abruptly at about 70 degreesC. It is shown experimentally that the formation of dot clusters at a high immersion temperature is explained on the basis of thermodynamics, whereas that of oriented rod clusters at a low temperature is explained by a kinetics-controlled mechanism.