Rare Earth Metal Oxides as High-K Gate Insulators for Future MOSFETs

摘要

Development of a high-K gate insulator is certainly the most urgent issue amongthe necessary technology items for the next generations of scaled CMOS, andmany organizations in the world are now seriously engaged in this research.Among the high-K dielectric materials, Zr02 and HfO2 so far have been regardedas the most promising candidates. Excellent results of high-performanceMOSFETs with small gate leakage current have been reported. However,problems such as interfacial layer growth and micro-crystal formation during thethermal process have been delineated as the materials come to be applied in theCMOS fabrication process. Although some good solutions to the problems havebeen shown," it is now expected that a longer development period will benecessary.