A NEW GATE CURRENT EXTRACTION TECHNIQUE FOR MEASUREMENT OF ON-STATE BREAKDOWN VOLTAGE IN HEMTS

We present a new simple three-terminal technique for measuring the on- state breakdown voltage in HEMT's. The gate current extraction techniq ue involves grounding the source, and extracting a constant current fr om the gate. The drain current is then ramped from the off-state to th e on-state, and the locus of drain voltage is measured. This locus of drain current versus drain voltage provides a simple, unambiguous defi nition of the on-state breakdown voltage which is consistent with the accepted definition of off-state breakdown. The technique is relativel y safe and repeatable so that temperature dependent measurements of on -state breakdown can be carried out. This helps illuminate the physics of both off-state and on-state breakdown.