A three-parameter model is developed and demonstrated for extracting the capacitance and parallel resistance for leaky capacitors. The technique combines dc and ac measurements to extract these values. The range over which the measurement is valid varies with the device, but is readily determined with a simple measurement. For devices with the highest dc leakage, minority carrier injection into the substrate can substantially increase the measured capacitance. This is not an artifact of the measurement procedure, but a real parasitic effect that increases the gate capacitance.
|Original language||English (US)|
|Number of pages||5|
|State||Published - Apr 2004|
|Event||Proceedings of the 13th Biennial Conference on Insulating Film - Barcelona, Spain|
Duration: Jun 18 2003 → Jun 20 2003
Bibliographical noteFunding Information:
This paper presents a simple method to extract a more accurate capacitance from conventional C – V data using dc measurements to help correct leakage current affects on ac measurements. The method allows one to measure the low-frequency C – V of moderately leaky devices (∼1 mA/cm 2 ) and the high-frequency C – V of very leaky devices (∼1 A/cm 2 ). We have also used this technique to extract the capacitance from split C – V measurements. Accurate determination of the accumulation capacitance in very thin devices is ultimately limited by minority carrier capacitance effects. If the modulation frequency ω is much less than the inverse of the minority carrier lifetime τ , the added capacitance is negligible compared to C OX . If ω ≪1/ τ a large capacitance can be observed in parallel with the oxide capacitance. The authors would like to acknowledge the support of the Semiconductor Research Corporation (contracts 859 and 1060).
- Capacitance measurement
- Leakage currents
- MOS capacitors