Back-End Integrable On-Chip MIM Decoupling Capacitors Featuring High Capacitance With Ultra-Low Leakage Current by Nitrogen-Incorporated HfZrOx

HfZrOx (HZO) crystallized in orthorhombic phase formed by plasma-enhanced atomic layer deposition (ALD) deposition and subsequent 400 °C annealing with TiN capping layer was employed as the dielectric for on-chip metal-insulator-metal (MIM) decoupling capacitors. With appropriate NH3 plasma treatment on HZO/TiN interface and bulk HZO to respectively, suppress interfacial scavenging effect and passivate defects pertinent to oxygen vacancies, enhanced k value of 28.9, high capacitance of 23.3 fF/μm² and low leakage of 0.16 fA/μm² at 1 V, 25 °C are achieved. With the plasma treatment, the improved interfacial and bulk quality that are confirmed by transmission electron microscopy and electron energy loss spectroscopy also lead to more desirable reliability of 10-year lifetime at 125 °C. The MIM capacitor technology exhibits performance that is notably advantageous over other high k dielectrics. More importantly, HfO2, ZrO2 and NH3 plasma treatment are all fab-friendly processes, with proper process integration, it is possible to further push the limit of their capabilities to realize decoupling capacitors eligible for sub-7 nm technology.