Improvement of water-related hot-carrier reliability by optimizing the plasma-enhanced tetra-ethoxysilane deposition process

Abstract

As-deposited, steam-exposed O-3-tetra-ethoxysilane (TEOS)-based intermetallic dielectric were characterized according to the LR-absorption spectra. The plasma-enhanced-TEOS films investigated here were formed by mixed-frequency plasma processes and differentiated by reaction oxidizers and/or plasma powers. Increasing stress and nitrogen or oxygen concentrations improved the moisture resistance of PE-TEOS oxide films. In addition to the moisture resistance of PE-TEOS films, another factor affecting hot-carrier robustness is the maximum thickness of the underlayer for O-3-TEOS films, which is limited by their conformity The integrated intermetallic dielectrics were evaluated by constant-current and hot-carrier stressing. In obtaining the best device reliability, a trade-off exists between moisture resistance, gapfilling capacity of the PE-TEOS underlayer, and plasma damage. Our results indicate that an O-2-rich, PE-TEOS film with a mechanical stress of 3 x 10(9) dyn/cm(2) is the optimum.