FIT-2, an extraction program based on the SPICE-PAC simulation software

FIT-2, an interactive program for extraction of transistor parameters for SPICE-like circuit simulators, is discussed. It is based on a circuit simulator rather than on an explicit set of model equations. Several optimization methods are built into the program to provide robust as well as sufficient fitting of device characteristics. The flexibility of the approach is obtained by specification of extraction details in the data sets rather than the extraction procedure. Extraction results for heterojunction bipolar transistors are used as an illustration of FIT-2's capabilities. Several directions for further research are identified. >