High resolution photothermal imaging of high frequency phenomena using a visible charge coupled device camera associated with a multichannel lock-in scheme

Citation
S. Grauby et al., High resolution photothermal imaging of high frequency phenomena using a visible charge coupled device camera associated with a multichannel lock-in scheme, REV SCI INS, 70(9), 1999, pp. 3603-3608
Citations number
11
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences","Instrumentation & Measurement
Journal title
REVIEW OF SCIENTIFIC INSTRUMENTS
ISSN journal
00346748 → ACNP
Volume
70
Issue
9
Year of publication
1999
Pages
3603 - 3608
Database
ISI
SICI code
0034-6748(199909)70:9<3603:HRPIOH>2.0.ZU;2-4
Abstract
We have developed a technique using a photothermal microscope from which we can make a thermal image of an electronic component working at a "high fre quency" using a charge coupled device (CCD) camera and a multichannel lock- in scheme. To do this, we have created an electronic "stroboscope": the fre quency F of the thermal signal induced by a high frequency electrical excit ation and the frequency of the light F+f that illuminates the device are ne xt to each other; the signal reflected at the surface of the device whose a mplitude is proportional to the variation of reflectivity and hence to the variation of temperature and whose frequency is the blinking one f is analy zed by a visible CCD camera. Amplitude and phase images of the high frequen cy thermal phenomenon can then be made. Moreover, this technique presents a great advantage: the spatial resolution is better than 1 mu m. The amplitu de and phase images presented show, with a very good spatial resolution, Jo ule and Peltier heating of a polycrystalline silicon 2.5 k Omega resistor a cross which a sinusoidal current is forced. (C) 1999 American Institute of Physics. [S0034-6748(99)03609-6].