Analysis of local lattice strain around oxygen precipitates in Czochralski-grown silicon wafers using convergent beam electron diffraction

The local lattice strain field around oxygen precipitates in Czochralski-grown silicon (CZ-Si) wafers has been measured quantitatively using convergent beam electron diffraction (CBED). As a result of the strain analysis from higher-order Laue zone patterns in the CBED disk, strain of the silicon lattices was found in the vicinity of oxygen precipitates, i.e., platelet type and polyhedral type. The strain along the normal direction to the precipitate is compressive, and the strain along the parallel direction to the precipitate is tensile. The lattice strain field around the precipitate decreases monotonically as a function of distance from the precipitate/matrix interface. Further, the morphological change in the growth process of the precipitate is important for the formation of the local lattice strain.