Ta₂O₅ capacitors' dielectric material forgiga-bit DRAMs

摘要

We fabricated 256-Mbit DRAM cells using a 0.5 μm high CROWNcapacitor with crystallized Ta₂O₅ dielectric film.We confirmed that the crystallized Ta₂O₅ (3.3 nmof SiO₂-equivalent thickness) was very stable in theconventional metallization process. The key issues for manufacturingwere to eliminate the hydrocarbon contaminants during high temperature O₂ annealing. Our preliminary investigation of Ta₂O₅ metal-insulator-metal (MIM) capacitors suggested that it ispossible to fabricate 1-Gbit DRAM cells using the amorphous Ta₂O₅ MIM capacitor with a CROWN structure