Oxynitride Gate Dielectrics for Deep Sub-micron MOS Devices

The continuous demand for improved CMOS transistors necessitate smailer device dimensions. The reduction in chip size into the deep sub-micron dimensions opens up new scientific and engineering challenges. One of the most critical material in developing deep sub-micron MOS transistors is high quality ultrathin (a few nm) gate dielectric film. As the gate dielectric thickness is reduced to below the 3 nm mark, the conventionally used SiOz creditability as a dielectric layer deteriorates. The incorporation of nitrogen atoms into the dielecinc has been shown to improve its characteristics: by reducing defect generation at the Si-SiO2 interface when incorporated at monolayer levels and reducing boron penetration from p+ poly-silicon gate electrodes through the dielectric films. The function of Si02 as an insulating layer for thickness < 2 nm becomes ineffective, as a result of high leakage current. This thesis deds with the development of oxynitride films as alternative gate dielecaics for deep sub-micron devices. Rapid thermal processing of nitrogen ionimplanted wafers and direct nitridation in N2 are the methods used in this work to grow oxynitride films. X-ray photoelectron spectroscopy (XPS) has been performed to study the chernical structure of the films. MOS capacitors with n* poly were fabticated to determine the potential usage of these oxynitride films in MOS transistors.