ASPECTS OF NITROGEN SURFACE-CHEMISTRY RELEVANT TO TIN CHEMICAL-VAPOR-DEPOSITION

NH3 is an important component of many chemical vapor deposition (CVD) processes for TiN films, which are used for diffusion barriers and oth er applications in microelectronic circuits. In this study? the intera ction of NH(3)( )with TiN surfaces is examined with temperature progra mmed desorption (TPD) and Auger electron spectroscopy. NH3 has two ads orption states on TiN: a chemisorbed state and a multilayer state. A n ew method for analyzing TPD spectra in systems with slow pumping speed s yields activation energies for desorption for the two states of 24 k cal/mol and 7.3 kcal/mol, respectively. The sticking probability into the chemisorption state is similar to 0.06. These results are discusse d in the context of TiN CVD. In addition, the high temperature stabili ty of TiN is investigated. TIN decomposes to its elements only after h eating to 1300 K, showing that decomposition is unlikely to occur unde r CVD conditions. (C) 1996 American Vacuum Society.