Experimental characterization of low-frequency noise in power MOSFETs for defectiveness modelling and technology assessment

In this work we analyse the applicability of low-frequency (LF) noise measurement in order to study the defectiveness in the gate oxide of power MOSFETs (Metal–Oxide–Semiconductor Field-Effect Transistors). To this purpose, we implement a low-noise experimental set-up, which is able to measure, in particular, the flicker (“1/f”) contribution to the drain noise current of the device under test, with high accuracy in terms of noise floor and the adequate bias system flexibility required by the application. First, we show how these measurements can be used to empirically detect the physical model and related compact expressions, which best describe the source of 1/f-like fluctuations in this type of devices. Then, according to the selected physical model, the defect density in the gate oxide is extracted. In order to validate the proposed methodology, experimental data are reported and discussed in the case of power U-MOSFETs.