Resistivity reduction and chemical stabilization of organometallic chemical vapor deposited titanium nitride by nitrogen rf plasma

Abstract

In situ, nitrogen rf plasma treatment of organometallic chemical vapor deposited (OMCVD) TiN, synthesized by thermal decomposition of tetrakis(dimethylamido) titanium, yielded films with low resistivity and enhanced chemical stability. A sequential OMCVD-plasma treatment process allowed deposition of films with bulk resistivity as low as 400 μΩ cm. The nitridation resulted in reduction of the carbon concentration in the films, and crystallization of TiN. The composition and electrical properties of the nitridized films were found to be stable upon air exposure. The films possess excellent step coverage (≳70% in 0.35 μm device structures with aspect ratio ∼3) and low defect density (∼0.06 cm−2 for defect size ≥0.2 μm).

Preparation of TiN films by plasma assisted atomic layer deposition for copper metallization

“…We do not understand at present why the use of hydrogen plasma yielded higher carbon levels in the films relative to those using nitrogen plasma. Initially, we expected lower levels of carbon in the films because the hydrogen radicals are expected to participate in the transamination reaction rather than a decomposition reaction [5,7]. Likewise, the use of nitrogen plasma is expected to increase carbon inclusion by enhancing the decomposition reaction of TDMAT.…”

Ultra thin CVD TiN layers as diffusion barrier films on porous low-k materials

“…One TiN deposition cycle includes 5 s barrier deposition and 30 s plasma treatment. The process is described particularly in [3,4]. The number of cycles determines the barrier thickness.…”

“…In this case the barrier integrity at the sidewalls of the structures is important because of two facts: (1) The plasma treatment after a barrier deposition cycle [3,4], which should result in a density increase of the deposited barrier layer, is less effective at the sidewalls of the patterned structures. So there might be a higher probability of copper indiffusion; (2) For the formation of the barrier at the porous sidewall dry etch and photoresist strip has an impact on the low-k dielectric.…”

Effects of plasma treatment in the tungsten process for chemical vapor deposition titanium nitride barrier film beyond nanometer technology

“…Meanwhile, the over-treatment changes the properties of the TiN film and even tungsten film [1,8]. Not many reports available in literature discuss the integration issue for VIA metallization and optimization as the VIA size shrinks.…”

“…For example, the CVD TiN process is applied with plasma treatment to reduce the impurity level, because the metallic organic compounds (such as tetrakis-dimethyl-amino-titanium, TDMAT, applied in the process reported in this paper) include lots of carbon and oxygen sources. The plasma treatment is generally recommended coupled with N 2 /H 2 treatment and to achieve lower resistivity for CVD TiN film [2,7,8]. The treatment efficiency directly contributes to the changes in film resistivity, orientation, adhesion, and grain size [2,3].…”