Study on Modeling of Transconductance Bimodal Effect in H-Gate PMOS

The H-gate SOI (silicon on insulator) PMOS plays an important role in SOI-technology circuit design because of its strong anti-radiation ability and good symmetry. However, since its transconductance has an obvious bimodal effect, the general BSIMSOI model cannot predict this type of device accurately. Such an effect brings new challenges to the simulation and prediction of device characteristics. To solve this problem, this work establishes a SPICE model of the H-gate PMOS devices by defining two parallel transistor channels in the sub-circuits based on the BSIMSOI simulation model. This model can effectively represent the bimodal effect of the transconductance of PMOS devices under the SOI process. Compared with BSIMSOI, the experimental results show the RMS value of the proposed model is reduced from 6.91% to 1.91%. At the same time, after using the bin parameters of BSIMSOI, the RMS value with a smaller size of W is reduced by more than 60%. The proposed model can be used in H-gate PMOS structure modeling and circuit design in the SOI process.