Development of a TiN-CVD process with very high step coverage

Current high-aspect ratio devices require deposition processes for conducting barrier and electrode films in vias and trenches with increasingly high aspect ratios. In this work we studied the extension of a CVD-TiN process based on the thermal deposition from TDEAT and NH₃ in combination with subsequent plasma treatment. We investigated the process parameter space (including deposition temperature, pressure, NH₃/TDEAT ratio and total gas flow) applying a DoE with respect to step coverage, deposition rate and electrical resistivity. One challenge is the quantitative determination of step coverage, which we overcame by using mapping Auger Electron Spectroscopy.