Radiative Measurement of Temperature in a MESFET Channel

A technique based on infrared-emission spectroscopy has been found to be useful for noncontact measurement of the temperature of a hot spot in the gate channel of a GaAs metal/semiconductor field-effect transistor (MESFET). Temperature measurements are important for the development of high-power GaAs MESFET and other advanced semiconductor devices because hot spots can affect operation and reduce operational lifetimes. An older passive infrared-sensing technique provides temperature measurements with a spatial resolution of 15 µm, which is much too coarse for determining local distributions of temperature in state-of-the-art devices with submicron-sized gate structures. The present technique affords a spatial resolution of about 0.5 µm.