RESISTIVITY REDUCTION AND CHEMICAL STABILIZATION CT ORGANOMETALLIC CHEMICAL-VAPOR-DEPOSITED TITANIUM NITRIDE BY NITROGEN RF PLASMA

In situ, nitrogen rf plasma treatment of organometallic chemical vapor deposited (OMCVD) TiN, synthesized by thermal decomposition of tetrak is(dimethylamido) titanium, yielded films with low resistivity and enh anced chemical stability. A sequential OMCVD-plasma treatment process allowed deposition of films with bulk resistivity as low as 400 mu Ome ga cm. The nitridation resulted in reduction of the carbon concentrati on in the films, and crystallization of TiN. The composition and elect rical properties of the nitridized films were found to be stable upon air exposure. The films possess excellent step coverage (>70% in 0.35 mu m device structures with aspect ratio similar to 3) and low defect density (similar to 0.06 cm(-2) for defect size greater than or equal to 0.2 mu m). (C) 1996 American Institute of Physics.