Blanket tungsten process requires a glue layer to have a good adhesion between CVD-W film and $SiO_2$ film. The effect of Sputtering conditions of glue layer TiW on the property of LPCVD-W film is studied.
The chosen variable process parameters of TiW sputtering are RF power and RF sputtering bias power. The condition of CVD-W is fixed at deposition temperature 300℃, $WF_6$ 3 sccm, $SiH_4$ 5 sccm, and $H_2$ 97 sccm.
The surface roughness, the residual stress and the adhesion of CVD-W films is measured by nanospec(reflectance mesurement mode), X-ray method, and scratch test, respectively.
The sputtering condition of TiW film had little effect on the surface roughness and the residual stress. But the adhesion of CVD-W film is closely related to the condition of sputtering condition of TiW film. Especially the adhision is greatly improved when TiW film is deposited through the bias sputtering.
It is found that the bias sputtring of TiW film is recomended method in order to use TiW film as a glue layer for VLSI metallization scheme.
