Characteristics of chemically vapor deposited TiN films prepared using tetrakis-ethylmethyl-amido-titanium

Abstract

Articles you may be interested inIn situ physical vapor deposition of ionized Ti and TiN thin films using hollow cathode magnetron plasma source Investigation on multilayered chemical vapor deposited Ti/TiN films as the diffusion barriers in Cu and Al metallization J.Low pressure chemical vapor deposition of TiN was studied with tetrakis-ethylmethyl-amido titanium ͑TEMAT͒ in a cold-wall-type vertical flow reactor with helium or ammonia. Thermal decomposition of the precursor under helium atmosphere yielded TiN films at substrate temperatures of 250°C. On the contrary, the reaction of TEMAT with ammonia occurred even at 100°C. The film growth rate increased with increasing deposition temperature and precursor mole fraction. However, deposition rate was greatly reduced in the system of ammonia/TEMAT compared to thermal decomposition probably due to a vigorous gas phase reaction in the latter case. For the case of thermal decomposition, the growth rate levels off at 325°C and this behavior has been interpreted as a transition from surface reaction to gas phase mass transfer control. The resistivity of the films deposited under similar conditions decreased with increasing thickness. It was found that higher deposition temperature and ammonia addition produced films of lower resistivity. Air exposure of the films caused an increase in resistivity, probably by oxidation of the films. Surface morphology of the TiN films in an ammonia-free system was smoother than that in the ammonia system. Conformality of the films strongly depended on the deposition temperature, ammonia usage, and ammonia flow rate. Lowering the deposition temperature and ammonia flow rate improved the conformality. Barrier performance of the TiN films deposited under helium atmosphere to copper diffusion in the Cu/TiN/Si structure showed an evidence of copper diffusion even after annealing at 550°C for 1 h.

Spectroscopic Evidence for Hydrogen Diffusion through a Several-Nanometers-Thick Titanium Carbonitride Layer on Silicon

“…High carbon content (from 25 to 35 at. % in these experiments, as confirmed by Auger electron spectroscopy, AES) is consistent with the previous studies. , The AES studies also confirmed the absence of silicon in the topmost layers, which suggests that the film produced is continuous. The thickness of the carbonitride layer was estimated to be ∼10 nm on the basis of the ex situ time-of-flight secondary ion mass spectrometry and atomic force microscopy (AFM) studies performed at the Surface Analysis Facility at the University of Delaware.…”

“…The root-mean-square roughness of this film was estimated to be ∼3-nm on the basis of AFM studies. Previous studies of TiCN films deposited from tetrakis(dialkylamino)titanium precursors at conditions similar to ours suggest that these films have amorphous structure, which is one of the main reasons why this approach leads to better conformal filling and a smoother surface than in the case of titanium nitride or titanium carbonitride with a low carbon content . The detailed structure of the films produced by such an approach in our studies is the subject of a separate publication…”

Vinyltrimethylsilane (VTMS) as a Probe of Chemical Reactivity of a TiCN Diffusion Barrier-Covered Silicon Surface

“…In the vast majority of devices, copper is separated from a semiconductor surface by a diffusion barrier material. One of the most prominent materials, possessing high thermal stability, good diffusion barrier properties, and low electrical resistivity is titanium nitride, TiN. − This material can be deposited on a semiconductor substrate using such chemical vapor deposition precursors as dialkyl-amino derivatives (Ti[NR 2 ] 4 , where R = Me, Et) − and TiCl 4 ,− used in combination with NH 3 and sometimes H 2 ; however, the latter method often presents significant problems associated with chlorine contamination and formation of NH 4 Cl. The chemical and physical properties of TiN films can be controlled by manipulating the carbon content, and in fact, titanium carbonitride films, TiC x N y , have been shown to have a set of very attractive physical properties, including better conformal filling than titanium nitride. − …”

Effect of NH3 on the preparation of TiNx films by laser CVD using tetrakis-diethylamido-titanium

“…deposition temperatures by CVD using metal-organic precursors such as tetrakis-dimethylamido-titanium (TDMAT) and tetrakisdiethylamido-titanium (TDEAT) [9]. However, the low deposition temperature (commonly less than 600 • C) has been found to yield poor crystallinity and low deposition rate (R dep ) [10,11], which is unattractive for the applications to high-speed cutting tools.…”