Identification and reduction of impurities in SOI wafers using secondary ion mass spectrometry and implantation-induced gettering

Abstract

Summary form only given. The authors have investigated secondary ion mass spectrometry (SIMS) relative sensitivity factors, detection limits, and interferences for the detection and determination of the densities of various impurities in SOI wafers (H, C, N O, Na, Al, K, Ti Ti, Cr, Mn Fe, and Cu) using both oxygen and Cs SIMS, with both positive and negative spectrometry. They have used implantation studies of rare isotopes as well as common isotopes and high mass resolution SIMS to sort out interference issues and to determine detection limits. Ion yields and relative sputtering rates were determined in the Si and SIO/sub 2/ SOI layers. More than 60 SOI structures, including devices, from various sources and annealed at various temperatures have been examined. The gettering action of C, P, and Ge ion implantation into SIMOX wafers, subsequently annealed at 1300 or 1350 degrees C), has also been studied. Significant redistribution (gettering) of Cu into the implanted region has been observed. >