THERMAL-WAVE IMAGING OF ELECTRICALLY HEATED MICROSTRUCTURES

The thermoreflectance technique is applied for imaging electric curren t distributions and thermal transfer in a temperature reference resist or heated by an alternating current. High-frequency scans (30 kHz) all ow imaging of the current density distribution in conducting strips of the resistor while scans of amplitude and phase of the surface temper ature variation at lower frequencies reveal plane, cylindrical, and sp herical thermal waves. We investigate wave dimensionality as a functio n of heating geometry and thermal length, and present a simple method allowing a quantitative thermal analysis by exploiting the phase profi le of cylindrical thermal waves. (C) 1996 American Institute of Physic s.