We have developed a high speed dynamic threshold voltage MOSFET named B-DTMOS for ultra low power operation. This was realized using a bulk wafer containing an individual trench isolated shallow-well with a high concentration buried layer sandwiched between two low concentration layers surrounded by a deep well. The B-DTMOS achieved an excellent propagation delay time of 83.6psec at 0.6V operation and 103.3psec at 0.5V operation. This was realized due to ultra low body resistance of the B-DTMOS.