Impact of body bias on the high frequency performance of partially depleted SOI MOSFETs

SOI MOS technology has been slated as the future ULSI technology because of its advantages in terms of speed, isolation, density, yield and performance. The superior speed advantage of the SOI devices has attracted much attention in both digital and radio frequency applications. In recent years, a number of direct current analysis based on the body-tied configurations of SOI devices have been reported. It has been confirmed that the body-tied configuration is one of the most effective and practical methods of suppressing the floating body effect and realizing the stable operation in SOI circuits, because the body potential of an SOI MOSFET´s is fixed. Body-tied configuration SOI MOSFET has therefore been employed for some crucial parts in circuits that require high stability such as dynamic circuits. However, to this date, high frequency performance of body-tied configuration SOI devices is mainly focused on the dynamic-threshold MOSFET in which the body of the device is tied to the gate. This particular device configuration makes the analysis of small-signal model complicated and does not reveal much insight into the body bias effect on the device high frequency performance. In this study, we investigated the impacts of body bias on the high frequency performance of PD SOI MOSFET and showed, for that both f_T and f_max are dependent on the body bias.