A first study was made of the effect of in situ ultrasound treatment during the ion implantation of crystalline material. Rutherford back-scattering spectroscopy, ion channelling and cross-sectional transmission electron microscopic measurements showed that amorphization during Ar ion implantation was enhanced by ultrasound treatment; especially at frequencies of around 2MHz. The effect of the amorphization process depended mainly upon ion flux, ion mass and ultrasound frequency. For implantation without amorphization, as in the case of implantation with atoms such as B, the defect concentrations were lower for wafers which were implanted with ultrasound treatment, as compared with control wafers which were implanted without ultrasound treatment. The effect of the ultrasound was explained in terms of its interaction with point defects, and the ultrasound-enhanced diffusion of interstitials.

Modification of the Si Amorphization Process by in situ Ultrasonic Treatment during Ion Implantation. B.Romanyuk, V.Melnik, Y.Olikh, V.Popov, D.Krüger: Semiconductor Science and Technology, 2001, 16[5], 397-401