Evaluation of interface-states density for MOSFETs fabricated on high-index (114) silicon surfaces

Metal-oxide-semiconductor field-effect transistor (MOSFET) devices were fabricated on high-index silicon (114) surfaces and their threshold voltage (Vth) and interface-states density (Dit) parameters were both evaluated for the first time. Even though MOSFET devices aligned at 0°, 30°, 60° and 90° off the equivalent [110] direction present two closely related average Vth values, Dit evaluation shows that for all channel orientations (0°, 30°, 60° and 90°), this high-index silicon (114) surface develops a high-quality interface with SiO₂ in which few electrons are trapped so that Dit as low as 10¹⁰ cm^-2eV^-1 can be obtained.