Measuring oxygen and bulk microdefects in silicon

Abstract Crystalline silicon grown with the Czochralski method contains high concentrations of oxygen, in the range of 5×1017–1×1018 at/cm3. Oxygen atoms initially occupy interstitial sites in the crystal lattice. However, due to high-temperature thermal treatments, oxygen can agglomerate to form precipitates, which can be quite large clusters of oxygen combined with crystal defects. Such clusters are often called as bulk microdefects. Oxygen increases the mechanical strength of silicon substantially, leading to increased resistance to plastic deformation, a particularly important property during high-temperature processing. Oxygen precipitates, on the other hand, affect wet etching properties causing defective etched surfaces. Therefore oxygen content is an important parameter and has to be controlled to maintain consistent, desirable wafer properties.