Determination of effects of deposition and anneal properties for tetranitratotitanium deposited TiO₂ dielectrics

Carbon and hydrogen free tetranitratotitanium was synthesized, which is believed to thermally decomposed primarily as: Ti(NO₃)₄→TiO₂+4NO₂+O ₂. The by-products of the thermal decomposition of tetranitratotitanium, which include NO₂ and O₂, may possibly provide a robust ultrathin tunnel interfacial layer. Due to the hydrogen free nature of thermolysis, N₂O may form an oxynitride layer which has been shown to produce thermal oxynitrides with higher quality than NH₃-based nitride oxides. Unlike titanium tetrakis isopropoxide (TTIP) deposited films, the interface state density more closely follows the "U" shape characteristic of conventional thermal SiO₂/Si interfaces. The integrated interface state density is considerably less for the film annealed at higher temperature, which should produce considerably higher inversion layer mobilities. This improvement of the interface, compared to TTIP deposited films, is believed to be due to the elimination of water vapor from the deposition ambient.