Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 6: Ge/Si I

HL 6.8: Vortrag

Montag, 26. März 2012, 11:15–11:30, EW 203

Observation of the oxygen precipitation in CZ-silicon by X-ray diffraction — •Christoph Bergmann, Johannes Will, Groeschel Alexander, and Magerl Andreas — Chair for Crystallography and Structural Physics, FAU Erlangen-Nuremberg, Erlangen-Germany

We investigated the formation, kinetics and final dissolution of oxygen precipitates in single crystalline silicon as a function of the temperature applied (up to 1200°C). The knowledge about and the control of such processes is one of the major challenges during the fabrication of integrated circuits. With the means of x-ray diffraction we examined the integrated intensity of a Bragg peak which is a direct function of the stress inventory introduced by the growing oxygen particles.

Samples cut in such a way that we were able to examine the whole radius of a 12" single CZ-Si crystal at once were illuminated with highly energetic X-radiation. Both in-situ and ex-situ measurements enabled us to follow the precipitation what gave strong indications for thermal donor formation, different point defect regimes along the radius ("V/G-model") and their influence on the precipitation regarding size, morphology and density of the precipitates grown.

A fit of the time-dependent evolution of the integrated intensity with a growth function given by the model of diffusion limited precipitation gave values for the precipitate density which excellently reproduce the values obtained by defect etching.