Comparison of MiM Performance with Various Electrodes and Dieletric in Cu Dual Damascene of CMOS MS/RF Technology

Abstract

In this paper, we have compared the performance of metal–insulator–metal (MiM) capacitors for different bottom electrode materials including Cu, , and Al in Cu–back-end-of-the-line (BEOL) process. A high-performance and low-defect-density MiM capacitor for mixed-signal and radio frequency (MS/RF) technology based on a complementary metal oxide semiconductor (CMOS) process was demonstrated. Q-factor can achieve for both Cu and Al at with MiM capacitors. showed a low Q-factor due to high resistivity. The process incorporates aluminum electrode into Cu–BEOL for MiM capacitor with a cost-effective process. The roughness of electro-dielectric interface by a thin aluminum electrode is critical for MiM performance due to field enhancement by roughness of a thin aluminum electrode. We have demonstrated a way to eliminate the roughness effect of thin Al and provide a MiM capacitor with high performance and low defect density. In particular, a method is demonstrated to achieve better matching, leakage, electrical breakdown, and temperature coefficient of capacitance performance for MiM capacitors.