A new reliable contact filling technology for submicron CMOS processes

An organic type of spin-on glass (SOG) was used to isolate barrier metal and Al in order to avoid the reaction of Al with Si through the grain boundaries of thin barrier metals. The planarization of the contact holes was achieved at the same time. The contact resistance remained low after annealing at 500°C for 30 min or 420°C for 6 h. The junction leakage current remained at a low level after annealing at 420°C for 10 h. Reliability testing was performed by use of a contact chain test pattern. The aging temperature was 125°C, and the current density was 1E5 A/cm². Contact resistance and junction leakage were extremely stable to beyond 1000 h. This new contact filling technology solves problems of barrier performance loss and topology planarization