A FULLY PLANARIZED MULTILEVEL INTERCONNECTION TECHNOLOGY USING SEMI-SELECTIVE TETRAETHOXYSILANE-OZONE CHEMICAL-VAPOR-DEPOSITION AT ATMOSPHERIC-PRESSURE

A new global planarization technology for interlayer dielectric films of multilevel interconnections has been developed. This technology utilizes a new semi-selective tetraethoxysilane-ozone (TEOS-Ozone) atmospheric pressure chemical vapor deposition (APCVD) SiO2 film formation and an organic SOG etchback techniques to achieve global planarization. The TEOS-Ozone APCVD SiO2 film thicknesses on Al runners are reduced by putting TiN and TiW films on top of the Al runners. This phenomenon is further enhanced by a CF4 RIE pretreatment. The TEOS-Ozone film thicknesses on the CF4 RIE pretreated TiN/Al and TiW/Al runners are about 43 and 80% smaller than those on the PECVD SiO2 field regions, respectively. A selective deposition mechanism is proposed. At the first stage, the deposition delay occurs on the CF4 RIE pretreated TiN and TiW films, due to the oligomer adsorption probability reduction by fluorine. Then the deposition rate reduction occurs due to the differences in metal oxide layer formation by O radicals at the metal film surfaces. A double level Al interconnection has been successfully fabricated using the semiselective TEOS-Ozone APCVD with an organic SOG etchback technique. The via hole resistance is about 140 m Omega/unit at a diam of 0.8 mu m, and is comparable to those using a conventional PECVD SiO2 film with an SOG etchback planarization.