A fully planarized mutilevel interconnection technology using both selective SiO2 and tungsten deposition techniques has been developed. Selective SiO2 deposition is performed by Liquid Phase Deposition (LPD) using a supersaturated hydrofluosilicic acid (H2SiF6) aqueous solution. LPD-SiO2 film deposition and its properties have been investigated. It has become clear that the film properties for interlayer dielectrics are superior to those of CVD-SiO2 film. Selectivity of LPD-SiO2 deposition to on CVD-SiO2 against on photoresist patterns is good. This good selectivity is caused by wettability difference. Full planarization of interlayer using selective LPD-SiO2 deposition with a photoresist mask has been realized. Fully planarized two level tungsten interconnection using both LPD-SiO2 deposition and selective CVD via filling has been demonstrated. Via hole contact resistance was as low as 0.33 Ω at the diameter of 0.8 μm.
|Number of pages
|NEC Research and Development
|Published - 1991 Jul 1
ASJC Scopus subject areas
- Electrical and Electronic Engineering