AVS 47th International Symposium
    Plasma Science and Technology Monday Sessions
       Session PS-MoM

Paper PS-MoM8
The Influence of High Density Plasma on TiN Films Deposited by Ionized Physical Vapor Deposition

Monday, October 2, 2000, 10:40 am, Room 311

Session: Plasma-Surface Interactions I
Presenter: D. Mao, Northeastern University
Authors: D. Mao, Northeastern University
J.A. Hopwood, Northeastern University
K. Tao, Northeastern University
Correspondent: Click to Email
The deposition of adhesion layers, diffusion barriers, and seed layers into high-aspect-ratio features is a critical technology for next-generation integrated circuit interconnects.@footnote 1@ One promising method of fabricating high-aspect ratio vias is ionized physical vapor deposition(I-PVD). Titanium nitride films were prepared by I-PVD in a gas mixture of argon and nitrogen. To understand the deposition mechanisms, optical emission spectroscopy analysis, Langmuir probes, and quadrapole mass spectrometry(QMS) were utilized to characterize the plasma. From the results of QMS, the dissociation of N@sub 2@ is as high as 50% for low N@sub 2@ partial pressure(~1.5mtorr), but decreases to 15% at 3.5mtorr. The properties of the TiN@sub x@ films were investigated by Rutherford backscattering, scanning electron microscopy(SEM), stress measurement, and electrical resistivity measurement. The ability of I-PVD to deposit titanium nitride at the bottom of narrow, deep vias and trenches was characterized by cross sectional SEM. The resistivity was found to increase as the N@sub 2@ partial pressure increases. The stress was found to increase from 1 GPa to 7 GPa as the bias voltage changes from -20V to -50V. The effect of nitrogen on the degree of ionization of sputtered titanium will also be discussed. The effect of dissociation of nitrogen and ion density on the characteristics of the TiN@sub x@ film will be presented by comparison with standard sputtering. @FootnoteText@ @footnote 1@ J. Hopwood, 'Ionized physical vapor deposition of integrated circuit interconnects', J. Physics of Plasmas, Vol. 5, pp 1624 (1998)