Performance Improvement of Sm2O3 MIM capacitors by using plasma treatment after dielectric formation

Abstract

In this letter, we investigate the dependence of the performance of metal-insulator-metal (MIM) capacitors with Sm2O3 dielectric on plasma treatment (PT) performed before Sm2O3 deposition, after Sm2O3 deposition, or both before and after Sm2O3 deposition. By performing PT in N2 ambient (FTN) after Sm2O3 dielectric formation, the effective quadratic voltage coefficient of capacitance (VCC) can be reduced from 498 to 234 ppm/V2 and the effective linear VCC can be reduced from 742.3 to 172 ppm/V for MFM capacitor with Sm2O3 dielectric having a capacitance density of ~7.5 fF//μm2. The leakage current density at +3.3 V can be reduced from 3.44 × 10-7 to 1.60 × 1O-8 A/cm2 by performing PTN in both before and after Sm2O3 deposition. PTN after dielectric formation is an effective way to improve the performance of high- κ dielectric MIM capacitors for RF and analog/mixed signal IC applications. © 2009 IEEE.