Effective Width Modeling for Body-Contacted Devices in Silicon-On-Insulator Technology
S. Khandelwal, E. Tamilmani, K. Shanbhag, J. Watts
IBM SRDC Bangalore, IN
Keywords: width-offset, SOI, body-contact
Abstract:Body-Contacted (BC) devices are extensively used in silicon-on-insulator analog circuits to avoid kink effect. This effect is not desirable as it changes gain of device suddenly. But to make body-contact special layout schemes are used. This paper has reference to them. These special layouts causes effective width of the BC device to increase. This increase in the effective width is modeled with non-binable parameter called “Width offset for Body-contact Isolation Edge” (dwbc) in BSIMSOI. But in standard BSIMSOI this parameter is constant with respect to channel length of device. This paper demonstrates channel length dependence of dwbc parameter using simple technique. This work also models the observed dependence semi-empirically. The improvement in fits obtained with proposed model over standard BSIMSOI validates the proposed model.