An integrated, tunable capacitor has terminal regions that extend
significantly deeper into the semiconductor body than the customary
source/drain terminal regions in the conventional CMOS varactors. For this
purpose, by way of example, well-type regions or collector deep
implantation regions may be provided, with which the depleted regions
occurring in the event of large tuning voltages extend significantly
further into the semiconductor body. The varactor with a large tuning
range can be produced without additional outlay in mass production methods
and can be used, for example, in phase-locked loops.
