Density Evaluation of Silicon Thermal-Oxide Layers on Silicon Crystals by the Pressure-of-Flotation Method

In this paper, density and thickness evaluation of a thin film on a silicon crystal by mass and density comparisons is described. Silicon thermal-oxide layers are prepared on a Cz-silicon single crystal by the thermal-oxidation technique, and their densities are evaluated. Thermal-oxide layers annealed at lower temperature become dense, and the density of the thermal-oxide layer annealed at 900 C in dry-O₂ atmosphere is estimated to be (2249 3) kg/m3³ . A relative standard uncertainty of the density measurement has been estimated to be about 0.1%-0.2% for silicon thermal-oxide layers