Automated Data Acquisition System For FET Measurement and it´s Application

The new measurement-based HP FET Model [l] greatly improves large-signal accuracy because the model nonlinearities are explicitly constructed from device data. To achieve this accuracy, a software product based on the HP IC-CAP program was developed to acquire FET data and package it for use in a nonlinear circuit simulator. This paper describes an adaptive, automated data acquisition system (ADAS) for device on-wafer measurements and its application to the HP FET Model generation process. The ADAS solves the problem of automatically determining the entire, device-specific, safe operating region of the FET from only data sheet information. The system adaptively chooses the bias points at which to measure, collects DC and small-signal S-parameter data, and sends it to the HP FET Model-Generator where it is packaged for use with the new HP FET Model. Because the techniques involved are very general, they can be easily applied for characterizing other classes of devices and to provide FET data for more conventional parameter extraction techniques.