Thermal metalorganic chemical vapor deposition of Ti-Si-N films for diffusion barrier applications

Structurally disordered refractory ternary films such as titanium silicon nitride (Ti-Si-N) have potential as advanced diffusion barriers in future ULSI metallization schemes. Here we present results on purely thermal metalorganic chemical vapor deposition (CVD) of Ti-Si-N. At temperatures between 300 and 450 degrees C, tetrakis(diethylamido)titanium (TDEAT), silane, and ammonia react to grow Ti-Si-N films with Si contents of 0-20 at.%. Typical impurity contents are 5-10 at.%H and 0.5 to 1.5 at.% C, with no O or other impurities detected in the bulk of the film. Although the film resistivity increases with increasing Si content, it remains below 1000 mu Omega-cm for films with less than 5 at.% Si. These film are promising candidates for advanced diffusion barriers.