Thermoreflectance temperature measurement with millimeter wave

Christophe Pradere (1) , Jean-Pascal Caumes (1) , S. Benkhemis (1) , Gilles Pernot (2) , E. Palomo (1) , Stefan Dilhaire (2) , Jean-Christophe Batsale (1)

1 I2M - Institut de Mécanique et d'Ingénierie de Bordeaux
2 LOMA - Laboratoire Ondes et Matière d'Aquitaine

GigaHertz (GHz) thermoreflectance technique is developed to measure the transient temperature of metal and semiconductor materials located behind an opaque surface. The principle is based on the synchronous detection, using a commercial THz pyrometer, of a modulated millimeter wave (at 110 GHz) reflected by the sample hidden behind a shield layer. Measurements were performed on aluminum, copper, and silicon bulks hidden by a 5 cm thick Teflon plate. We report the first measurement of the thermoreflectance coefficient which exhibits a value 100 times higher at 2.8 mm radiation than those measured at visible wavelengths for both metallic and semiconductor materials. This giant thermoreflectance coefficient κ, close to 10−3 K−1 versus 10−5 K−1 for the visible domain, is very promising for future thermoreflectance applications.

Domaines: Optique [physics.optics]

Christophe Pradere, Jean-Pascal Caumes, S. Benkhemis, Gilles Pernot, E. Palomo, et al.. Thermoreflectance temperature measurement with millimeter wave. Review of Scientific Instruments, 2014, 85 (6), pp.064904 (1-3). ⟨10.1063/1.4884639⟩. ⟨hal-01064000⟩