Double modulated thermoreflectance microscopy of semiconductor devices

Abstract

Photothermal microscopy based on combined optical and electrical excitation has been applied to insulating lines and conducting channels on SIMOX mesas prepared by focused ion beam implantation. The double excitation technique permits imaging of electrical properties of the implanted structures yielding complementary information achievable by a single excitation defect tracing. In addition, the contrast of the images of implanted structures can be increased considerably. The best contrast for the observation of insulating lines adjacent to a conducting channel has been achieved by recording the modulated reflectance signal at the fourth harmonic of the modulation frequency used for electrical and optical excitation. The contrast enhancement is found to be mainly due to thermal origins caused by the photoinduced currents, which can act as an additional heat source.

Simultaneous determination of thermal diffusivity and thermal conductivity of a thin layer using double modulated thermal excitations

“…Geiler et al 25 used double laser beams with different wave lengths in order to generate the differential frequency in the sample by photothermal modulation of the refractive index. In this context, Dietzel et al 26 developed the double modulated thermoreflectance microscopy of semi-conductor devices based on combined optical and electrical excitation. However, in these latter works, the problem of a semi-infinite layer has been studied extensively, and those with a finite layer do not offer analytical solutions.…”

Study of laser excited vibration of silicon cantilever

“…[6][7][8][9][10][11] Due to the merits of noncontact and nondestructive behavior, these methods are widely used as a detection way in microelectromechanical system ͑MEMS͒ and nanoelectromechanical system, especially in situations where other techniques are not useful. [13][14][15][16][17][18][19][20][21] For semiconductor materials plasma waves, generated by the absorbed intensity-modulated laser beam, can play the dominant role in the PA and PT experiments. A lot of excellent works have been done both in experimental and in theoretical fields.…”