A fully planarized multilevel interconnection technology using selective TEOS-Ozone APCVD

A new interlayer dielectric film planarization technology for sub-half-micron multilevel interconnections has been developed. This technology utilizes a new selective TEOS-Ozone APCVD SiO/sub 2/ film formation technique which can be realized by differences in surface adsorption properties and flow characteristics of siloxane oligomers. The deposition rate can be reduced by putting Ti or its alloy metal films such as TiN and TiW on top of Al wirings. These metal films can reduce the oligomer adsorption and assist the oligomer flow into the spacings between Al wirings. Furthermore, the selectivity is enhanced by a CF/sub 4/ gas plasma pre-treatment, even on top of the W films. The TEOS-Ozone APCVD SiO/sub 2/ films deposited on the Ti/Al, TiN/Al, TiW/Al or W/Al wirings with the CF/sub 4/ pre-treatment were more than 40% thinner than those on PECVD SiO/sub 2/ under-layers. Higher capability for both local and global planarization of interlayer dielectrics was confirmed in a multilevel metallization scheme in the double-level Al interconnection technology with the 0.6 mu m design rule and in a prototype 64M DRAM fabrications.<
>