Inter-metal inorganic spin-on-glass dielectric layer in 100 nm generation technology

This study investigates inter-metal dielectric (IMD) layer with a perhydro-polysilazane-based inorganic spin-on-glass (PSZ–SOG) dielectric layer in 100 nm node multilevel metallization technology. When the PSZ–SOG film is cured in N2 ambient, the via resistance is worsened; the via resistance declines as the number of wafers in sequence increases because the SOG film tends to adsorb a large amount of moisture and forms a porous IMD film structure. However, when it is cured in O2 ambient, optimization by via adhesion degassing can minimize the slot effect and yield good via resistance. In this study, the non-etchback PSZ–SOG process is integrated by using 100 nm multilevel metallization technology without an expensive high density plasma chemical vapor deposition (HDP CVD) oxide process or modification of design rules. After the SOG curing recipe and degassing condition in the via adhesion film deposition have been optimized, the PSZ–SOG exhibits excellent planarization, a dense IMD structure and good via resistance performance that is comparable with that of the traditional HDP CVD oxide process.