Novel Integration of Metal–Insulator–Metal (MIM) Capacitors Comprising Perovskite-type Dielectric and Cu Bottom Electrode on Low-Temperature Packaging Substrates

In this letter, a novel integration scheme, for metal–insulator–metal capacitors comprising perovskite-type dielectrics and Cu-based bottom electrodes, has been demonstrated on low-temperature FR4 packaging substrates. Cu oxidation during dielectric deposition and postannealing is completely avoided by a dielectric-first process flow with Ti as oxygen-getter. By using evaporated barium strontium titanate as capacitor dielectric, a maximum capacitance density (∼1250 nF/cm at 100 kHz) and moderate leakage current (< 4 × 10−5 A/cm at 2 V) have been achieved with rapid thermal annealing at 700 ◦C. Higher temperature leads to dielectric degradation. Combined with advanced deposition techniques, this integration scheme enables realization of high-performance embedded capacitors that can be integrated with printed circuit board technology.