A novel 4T SRAM cell using 'self-body-biased" SOI MOSFET structure operating at 0.5 volt

A novel 4T SRAM cell utilizing the 'self-body-biased' ('SBB') SOI MOSFET structure (Terauchi and Terada, Proc. IEEE Int. SOI Conf., p. 36, 1999) is proposed. The body region of an SOI MOSFET with an 'H-shaped' gate electrode is used as a resistor in the inverter pair of the SRAM cell. The resistance of the body region is controlled by the low impurity concentration region beneath the auxiliary gate electrode and its geometry, independently from the threshold voltage of the MOSFET. Device simulation reveals the stable operation of the proposed SRAM cell under supply voltage of as low as 0.5 V.