Analýza světlo rozptylujících defektů na povrchu leštěné křemíkové desky

Abstract

The essential part of silicon wafer manufacturing is a surface defect and particle control on polished silicon wafers. Prediction of the point defect formation during silicon single crystal growth by Czochralski method has a significant impact on the presence of COPs (Crystal Originated Particles) on the polished silicon surface. After the polishing process chemical residues adhering to the silicon wafer surface are removed by a multi – step cleaning process. Submicron particles (resistant to cleaning processes) and COPs are inspected by optical particle counter. The principle of defect and heterogeneous particle distinction is important for the surface analysis by the inspection system. Heavily boron – doped silicon wafers with crystallographic orientation (111) were selected to distinguish rate of particle contamination and COPs. In this work, radial distribution of COP defects and their density, depending on the boron concentration are studied. Axial distribution of vacancy region within the crystal is found. Using the oxidation test vacancy central region on the radial profile of wafer (identical to COP defect area) can be compared to the area bounded by ring consisting of stacking faults. The next section focuses on analysis of particle count on the wafer surface and possible pH dependence of final polishing slurry.