Low-temperature direct nitridation of silicon in nitrogen plasma generated by microwave discharge

Abstract

Plasma nitridation of silicon has been performed at low temperatures (at ≊500 °C and also lower temperatures) in nitrogen plasma generated by microwave discharge. The effects of various growth parameters such as microwave power, nitrogen gas pressure, anodization current and polarity, growth time and substrate temperature on the thickness, surface morphology, uniformity, composition and stoichiometry, and electrical and physical characteristics of the grown films have been studied. The thickness of the grown films varied between 30 and more than 100 Å depending on the growth conditions. Based on the grazing-angle Rutherford-backscattering data, the grown films were silicon nitride with some oxygen and carbon contamination. A typical breakdown field of ≊10 MV/cm was measured for these films. The preliminary results obtained indicate that these nitride films can be considered as potential candidates for ultrathin gate, tunnel, and dram memory insulators for very large scale integration devices.