The thin-film reaction between Ti and thermally grown SiO2

Medium-energy ion scattering was used to examine the reaction between a thin Ti film (4×1015 Ti atoms/cm2) and a thermally grown SiO2 substrate. The reaction was monitored after deposition at room temperature and after annealing, up to a temperature of 800 °C. During deposition, oxygen from the SiO2 substrate dissolves into the Ti film (up to 38% oxygen) without the occurrence of Ti-Si intermixing. Heating of the sample causes a loss of oxygen but no loss of titanium. Instead, islands of titanium silicide and areas of bare Si surface are formed after an 800 °C anneal for 250 min. A comparison of the room-temperature reaction for the ternary Ti-O-Si system and the binary Ti-Si system is also given.