Thermoreflectance based thermal microscope

Thermal images of active semiconductor devices are acquired and processed in real time using visible light thermoreflectance imaging with 34 mK sensitivity. By using a 16316 alternating current coupled photodiode array with synchronous frequency domain filtering a dynamic range of 123 dB is achieved for 1 s averaging. Thus with a stable and higher power light source, fundamentally the camera can reach 6 mK sensitivity over a submicron area. The number of pixels in the image is increased to 1603160 by multiple frame image enhancement and submicron spatial resolution is achieved. The photodiode array system has a maximum 40 kHz frame rate and generates a synchronous trigger for recovery of the phase signal. Amplitude and phase images of the thermoreflectance signal for 50350 micron square active SiGe based microcoolers are presented. © 2005 American Institute of Physics. fDOI: 10.1063/1.1850632g