Magnetic sensors are useful in applications such as magnetic read heads and non-contact current sensors. Ideally, a magnetic sensor should be easily integrated with its peripheral circuits. Experimental results indicate that it is possible to convert a conventional MOS transistor into a magnetic sensor by splitting the drain of the device into two. Such a device is attractive because the device is completely CMOS compatible. Integration of the sensor with electronic circuits can be easily achieved. However to realize such an integration, simulation model compatible with circuit simulators is essential. No such model has been reported. In this paper, we describe the development of a model for this split-drain MOS magnetic sensor which can be easily incorporated into popular circuit simulators such as SPICE. In developing this model, numerical simulations using symbolic mathematical tools are used to gain a physical understanding. The model is applicable for device operating in the linear region, and it is verified against experimental results.>

The successful modeling of short-channel transistor breakdown characteristics with effective channel length down to 0.6 mu m is reported. The sudden increase in the MOS drain current due to threshold voltage reduction caused by the forward biasing of the source-substrate junction is also modeled with considerable accuracy. This is the first successful application of a short-channel breakdown model in a circuit simulator. Model parameter extraction and installation of the model in the circuit simulator is also discussed.>

A circuit simulation model for subthreshold conduction of MOSFET is developed. This model employs a novel interpolation scheme to provide smooth transition from the subthreshold region to the above-threshold region. This interpolation scheme ensures that both channel current and its derivatives (or conductances) are smooth. Since an interpolation scheme is used, a simple, independent, and physically based model can be used for the subthreshold and the above-threshold region. The model is applied to subthreshold conduction for submicron MOSFET. It is also successfully installed in a circuit simulation program.