High-Density RF MIM Capacitors Using High-k La[sub 2]O[sub 3] Dielectrics

The integrity of the metal-insulator-metal (MIM) capacitor with high- k dielectrics formed using a 400°C back-end process was investigated. A very high capacitance per unit area of 9.2 fF/μm 2 was achieved for MIM capacitors at 1 MHz, significantly reducing the chip size of radio frequency (rf) circuits. A mathematical derivation, involving measured S parameters, yielded the small voltage-dependent capacitance ppm at 1 GHz, indicating that the precision capacitor circuit can be applied in the rf regime. Furthermore, such a high capacitance density can be maintained as the frequency is increased from 10 KHz to 20 GHz with a large Q factor ⩾90.