Q-factor Integrity of 28nm-node High-k Gate Dielectric

Quality-factor (Q-factor) applied to the telecommunication fields is an important index to represent the performance of a capacitor or an inductor in energy storage. It is appropriate to use this concept for verifying the integrity of 28nm high-k gate dielectric. The relationship of Q-factor and applied frequency can be approached with sensing the tested gate capacitors with the different frequency. The maximum Q-value demonstrates the minimum energy loss at this frequency operation. The sensed characteristic also illustrates the trap species in gate dielectric. If the Q-value at the high frequency is lower, the amount of the fast trap is tremendous. Inversely, while the Q-value at the lower frequency is lower than 1 kHz, the amount of slow trap is dominant in gate dielectric. This electrical measurement at the different gate patterns or gate dielectric deposition contribute to yield improvement, especially in RF IC designer's consideration.