Integrated MOS transistors having a gate metallization composed of tantalum or niobium or their silicides

摘要

Chemical reactions between a tantalum or tantalum silicide metallization layer and an underlying thin gate oxide are avoided by the interposition of an intermediate layer of oxygen-doped tantalum or tantalum silicide whose thickness amounts to about 1/20 to 1/5 of the layer thickness of the entire gate metallization. The metallization layer is produced by high-frequency sputtering in which oxygen is added at the beginning of the process and argon is used as a sputtering gas. Low specific resistance values are accomplished by means of this gate metallization.