Berlin 2012 – scientific programme
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DS: Fachverband Dünne Schichten
DS 14: Ion irradiation effects
DS 14.3: Talk
Tuesday, March 27, 2012, 12:15–12:30, H 0111
Ion beam induced stress formation and relaxation in semiconductors — Tobias Steinbach, •Aaron Reupert, and Werner Wesch — Institute of Solid State Physics, Friedrich Schiller University Jena
The irradiation of crystalline semiconductors leads to the formation of defects, which accumulate with increasing ion fluence until in many materials a continuous amorphous surface layer is formed. In general, this phase transition causes expansion of the materials due to density change, which consequently leads to the formation of stress. However only a few studies on ion beam induced stress phenomena have been made, even though stresses in microelectronic structures cause substrate bending, delamination and cracking as well as anomalous diffusion of dopands. To investigate the ion beam induced formation and relaxation of stress due to density change and plastic phenomena in semiconductors a new modified scanning laser reflection technique based on the concepts of Volkert1. was established at the FSU Jena. By means of this technique the bending of a freestanding sample away from the irradiated surface is defined by the compensation of forces and moments between the underlying substrate and the irradiated regions. We present a brief overview of the configuration and the general principle of this technique. Furthermore, first results from wafer curvature measurements made during amorphization are shown for the irradiation of germanium and silicon. The results will be discussed based on the effects of density change, radiation-enhanced plastic flow and plastic deformation. 1C. Volkert, J. Appl. Phys. 70, 3521 (1991)