SIMOX layers and interfaces studies with a new fast multichannel spectroscopic ellipsometer

A nondestructive optical technique, spectroscopic ellipsometry (SE), used to control top SiO₂, silicon, and buried SiO₂ layer thicknesses, as well as interfaces of these layers during SIMOX (separation by implantation of oxygen) wafer fabrication, is addressed. New improvements on SE give the capability to measure a complete spectrum within 1 s without losing useful information. Using this technique, it is also possible to characterize the evolution of layer thicknesses when the dose of implantation is increased at a given energy. The microspot option reduces the beam size from 3×9 mm² down to 150×150 μm²