A fast nondestructive method for determining the thickness uniformity of buried SiO2 layers and surface Si layers in SIMOX films

SOI-SIMOX (Silicon on Insulator-Separation by Implanted Oxygen) films were fabricated by China-made first 10 mA-oxygen implanter with doses of (1.4-1.6)×10¹² O⁺/cm² at energy of 150-170 keV. The SIMOX films were evaluated by means of infrared absorption spectroscopy (IR). There are three major characteristic peaks in the IR spectra. The three coefficients were calculated carefully. A new and fast nondestructive method in a few minutes to determine the thickness of both buried SiO₂ layers and surface Si layers in SOI structures is used by measuring the IR spectra without the destruction of the SIMOX wafers. The uniformity of buried SiO₂ and surface Si thickness and implanted dose is obtained in a few minutes by this method. We have finished the IR measurements on US-SIMOX, UK-SIMOX, Germany-SIMOX and China-made-SIMOX films. The results were discussed in detail. This method is very useful, economical and convenient for producing large scale numbers of SIMOX wafers in the future.