Chemical Stability of HBF4-Treated (100)Si Surfaces

Abstract
Si(100) surfaces were modified by means of enhanced RCA procedure with “ HBF4-last” and “HF-last”. Nulling ellipsometric (NE) and secondary ion mass spectrometric (SIMS) measurements revealed that HBF4-treated Si surface is more strongly passivated by hydrogen and fluorine than HF-treated one: the oxidation rate of the HBF4-treated Si surfaces in air was found to be lower than that of the HF-treate surface. Scanning tunneling microscope (STM) images of HBF4-cleaned surface after 18 h storage in air were quite stable during observation, scanning could be easily performed over a wide area on every plot we chose.