OXIDATION OF PURE SI3N4 - SPECTROSCOPIC ELLIPSOMETRY AND GLANCING ANGLE X-RAY-DIFFRACTION STUDIES

Spectroscopic ellipsometry and X-ray diffraction have been applied to characterize the initial oxidation behaviour of a pure Si3N4 material (HIPped without sintering additives) in the temperature range of 1000 degrees-1450 degrees C for about 1 hr. Single crystal Si has been used as reference. It has been found that the initial oxidation of the Si3N4 is a diffusion controlled process, and the oxide is much easier to devitrify than that on Si. The SiO2 growth rate at 1000 degrees C on the Si3N4 is similar to that on Si while it is almost twice at 1250 degrees C, no matter whether the Si2N2O exists in the oxide layer or not.