Automatic measurement system for the DC and low-f noise characterization of FETs at wafer level

In this work we propose a measurement setup topology suitable for the automatic DC and low frequency noise (LFN) characterization of field effect transistors at wafer level. The system is composed of source and measure units (SMUs), by a custom-built low noise amplifier (LNA), and by a PC based spectrum analyzer. No bias filters and switch matrices are used, allowing fast switching between DC and LFN measurements together with low leakage. The programmable LNA can reach background noise levels in the order of fA/Hz^1/2, while DC performances are limited by the SMUs. The main feature of the proposed system is the high degree of operational flexibility due to the complete PC-based software control. LFN characterization, down to bias DC currents of 1pA, in organic thin film transistors is reported to demonstrate system operation and performances.