Electrical and Micromechanical Performance of Ultrasonically Cleaned Silicon Wafers

A. Nadtochiy¹⁾, A. Podolian¹⁾, V. Kuryliuk¹⁾, A. Kuryliuk¹⁾, O. Korotchenkov¹⁾, J. Schmid²⁾, V. Schlosser²⁾

1. Faculty of Physics, Taras Shevchenko Kyiv National University, Kyiv

2. Department of Electronic Properties of Materials, Faculty of Physics, University of Vienna

ABSTRACT: The evolution of the electrical and micromechanical properties of Si wafers subjected to a kHz-frequency ultrasonic treatment in a water-containing ultrasonic cleaning bath is reported. The cleaning stages observed with varying treatment time are discussed. It is believed that, wafer treating during the first approx. 60 min is capable of removing contaminating particulates from the wafer surface and actives interface dangling bonds. These are leading to a decrease of subsurface resistance towards dislocation displacements as observed by the micro-hardness decrease, affect free carrier migration barriers seen in variations of the I–V barrier heights, and acts as recombination centers resulting in accelerated photovoltage decays. Although an exact mechanism is not yet clarified, a partial healing of the bonds may occur at longer cxcitation times (approx. 60-120 min) thus partially reversing the observed changes.