Synthesis and characterization of silicon dioxide thin films by low pressure chemical vapor deposition using ditertiarybutylsilane and oxygen

This study is focused on the synthesis and characterization of silicon dioxide thin films deposited on silicon wafers by Low Pressure Chemical Vapor Deposition (LPCVD), using ditertiarybutylsilane (DTBS) as a precursor and oxygen as the oxidant. The dependence of film growth rate on various process parameters were studied. The growth rate was found to follow an Arrhenius curve with the variation in the temperature with an activation energy of 12.6 kcal/mol. The growth rate was found to be inversely proportional to the temperature in the range 550-750 °C. The refractive index and density were observed to be close to 1.47 and 2.71 g/cm3 respectively with flow rate ratio O2/DTBS = 2/1. Producing crack-free thick oxide films were performed at two different conditions. One was at 850 °C with flow rate ratio O2/DTBS = 5/1 which produced compressive stress with lower growth rate, and the other was at 700 °C with flow rate ratio O2/DTBS = 10/1 which produced tensile stress with higher growth rate. Both conditions were able to produce about 10 μm oxide films with no sign of cracking