Tan Based Metal-Insulator-Metal Capacitor with Excellent Long-Term Reliability

Improving the long-term reliability of MIM capacitor is essential to tap its potential in IC application. At present, TiN is the mainstream material used for MIM capacitor metal plate with Si
3
N
4
as insulator dielectric. However, the resistance characteristics of TiN are temperature unstable, and it has large lattice mismatch with Si
3
N
4
, which is detrimental to the device long-term reliability. Herein, we propose a strategy to employ TaN as MIM capacitor plate to solve these drawbacks. Experimental results reveal that the composition optimized TaN plate achieves a TCR near to zero. Finally, TDDB test reveals that the TaN based MIM capacitor can achieve more than 10
⁶
years of long-term reliability, which is two orders of magnitude longer than TiN based device.