A precise MOSFET model for low-voltage circuits

A MOSFET model that is capable of handling the drain current above 10
^-10
A within the temperature range of 220-340 K is proposed. The key feature of the model is that surface potentials at source and pinchoff points are used for the purpose of obtaining a smooth connection between the current solutions in the tail and the saturation regions. Comparison of the model with experiments has been carried out using n-channel MOSFET's with 7 × 10
¹³
, 7 × 10
¹⁴
, and 4 × 10
¹⁵
cm
^-3
substrate impurity concentration and 675-, 1470-, and 5030-Å gate-oxide thickness. The theoretical calculations are in excellent agreement with the experimental measurements. It is shown that low-level current has a strong influence on the low-voltage static inverter circuit and dynamic memory.