METHOD FOR SIMULATING DENSITY DISTRIBUTION AND SIZE DISTRIBUTION OF OXYGEN PRECIPITATION NUCLEI IN SINGLE CRYSTAL

摘要

PPROBLEM TO BE SOLVED: To predict the density distribution and size distribution of oxygen precipitation nuclei in a single crystal accurately. PSOLUTION: At first to seventh steps, temperature distribution in a single crystal 14 growing from melt 12 is determined using a computer from the pulling time of the single crystal to the finish time of cooling while taking account of the convection of the melt. At eighth to fourteenth steps, void density is determined using the computer by taking account of the cooling process of the single crystal separated from the melt and reflecting the effect of gradual and quick cooling of the single crystal on the result, and then the void radius and the thickness of an inner wall oxide film growing around the void are determined in relation to each other using the computer. At fifteenth to seventeenth steps, the generation of oxygen precipitation nuclei per unit time and the critical radius are determined using the computer. When the generation of the oxygen precipitation nuclei per unit time exceeds zero, calculations of the void radius and the thickness of the inner wall oxide film are stopped and the radius of the oxygen precipitation nucleus is determined using the computer. PCOPYRIGHT: (C)2005,JPO&NCIPI