FABRICATION OF MIDGAP METAL GATES COMPATIBLE WITH ULTRATHIN DIELECTRICS

A process has been described which can produce a midgap tungsten gate compatible with the current and future complementary metal-oxide-semic onductor technology. The tungsten was deposited directly onto a 3.0 nm SiO2 gate dielectric without measurable degradation of any of its ele ctrical properties. The tungsten deposition process yields no reactive or corrosive by-products that affect the gate dielectric integrity. T he tungsten film is found to be pure within the limits of several anal ytical techniques and the resistivity of the tungsten films was found to be within a factor of 2 of the bulk value. (C) 1998 American Instit ute of Physics.