Measuring the threshold voltage of a MOSFET with an active attenuator

By using a MOS active attenuator which contains only two MOS transistors fabricated in a common substrate, a technique is presented to extract the threshold voltage of a MOSFET under tests. The active attenuator can be easily implemented with very small chip area in the test chips of a wafer and the extracting procedure can be performed quite fast. Hence, this technique is suitable for threshold voltage extraction that is important in MOSFET characterization and process monitoring. HSPICE Simulation and experimental results are given to verify this proposed scheme