Low-rate plasma oxidation of Si in a dilute oxygen/helium plasma for low-temperature gate quality Si/SiO2 interfaces

Abstract
Low‐rate plasma oxidation of Si, involving a small oxygen concentration in a low‐power He plasma at low processing temperatures (∼350 °C), is shown capable of producing excellent interface properties, good uniformity, and low defect density. As an interfacial layer for plasma‐enhanced chemical vapor deposited (PECVD) SiO2 films, the plasma oxide is key to achieving high quality composite (plasma oxide/PECVD) oxide structures, which essentially match the electrical quality of thermal oxides. Such low‐temperature oxide films are suitable for critical device applications, such as the gate oxide in metal‐oxide‐semiconductor devices and the base passivation layer in advanced bipolar devices.