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Benjamin Chow, Andy Hegedus, Pravin Narwankar, Chris Olsen, Gary Miner, Arnaud Lepert & Paul Meissner, Applied Materials,

ABSTRACT

As the drive to increase transistor speeds intensifies, materials with a higher dielectric constant are being used to replace SiO2, and these materials (usually rare earth oxides) are being deposited in thinner films. However the decrease in gate oxide thickness now faces physical and technical limitations. One approach to the problem is to raise the dielectric constant by incorporating nitrogen into the gate oxide. Thermal nitridation has been a standard technique but gives degrading effects on the electrical properties. This paper discuses an innovative approach to satisfying the gate dielectric requirements at 90nm using decoupled plasma nitridation rather than thermal, to provide scalable equivalent oxide thickness, reduced leakage and improved reliability.