Non Invasive Thermal Imaging of GaAs MESFET's

We demonshate the use of an infrared focal plane array (IR-FPA) to measure the spatially-resolved surface temperature of a GaAs MESFET (gallium anenide metal-semiconductor field-effect lransistor) under DC and RF operating conditions. By compensating for variations of the small emissivity, absolute temperatures of +/- 5 oC, and small temperature differences of 1 oC can be determined. By deconvolution of the lens MTF (modulation transfer function) we attain a resolution of 6.25 um. The combination of thermal and spatial sensitivity makes our set-up ideally suited for non-destructive characterisation of semiconductor devices