LPCVD WSi2 Films Using Tungsten Chlorides and Silane

This paper makes a systematic study of blanket and selective low pressure chemical vapor deposition (LPCVD) WSi 2 films from tungsten chlorides, silane, hydrogen, and argon on silicon as well as on patterned oxidized silicon substrates. Experiments were performed by varying the initial gaseous WCl 4 to SiH 4 ratio (Rx) or the deposition temperature (T d ). Initially, yield and CVD-phase diagrams of the W-Si-Cl-H-Ar chemical system were drawn, based on thermodynamic simulations. The deposition of pure WSi 2 phase and mixed solid phases involving W, W 5 Si 3 , WSi 2 , and Si was predicted to occur in relation to process parameters