A twin-MOSFET structure is proposed for suppression of the kink and parasitic bipolar effects in SOI MOS transistors. It is also an attractive candidate to provide satisfactory linear device operation at liquid He temperature. The device consists of two transistors in series with a common gate but it operates as a single transistor. Kink effect can be confined to the one "slave" transistor while the other "master" transistor can be kept free from the kink effect. If the gate length of the master transistor is larger than that of the slave one, the kink-free master transistor dominates the overall output characteristics of the device. As a consequence, the kink effect is suppressed in the overall output characteristics of the device. Furthermore, the parasitic bipolar effect in SOI MOSFETs is also significantly reduced and the saturation drain output impedance as well as the output breakdown characteristics are drastically improved. Kink-free and very flat output characteristics are obtained at both room and liquid He (4.2 K) temperatures.