Passivation of Si and SiGe/Si Structures with 1-Octadecene Monolayers

The electrical properties of structures included 1-octadecene (CnH2n, n=18) monolayers deposed onto the oxide-free silicon surface or Si/SiGe/Si layers were analyzed as a function of surface pretreatment (hydrogen- or iodine-terminated silicon surface) and layer deposition regime (thermal- or photo-activated process). Two types of traps (for electrons and holes) were found at the interface between the monolayers and substrate. The density of traps was shown to depend on the, H- or I-termination of the silicon surface, the illumination intensity and deposition time during photo-activated deposition, and the temperature of thermal-activated deposition. The optimal regimes can be chosen for minimization of the surface charge in the structures covered with 1- octadecene monolayers, which provides a high conductivity of thin near-surface layers.