Systematic Analyses of Practical Problems Related to Defects and Metallic Impurities in Silicon

Abstract

AbstractSystematic approaches are introduced for (i) oxygen precipitation behavior, which is important for internal gettering, and (ii) segregation induced gettering behaviors of p/p+ epitaxial wafers and Poly-Si Back Seal (PBS) wafers. (i) Oxygen precipitation behavior during a whole sequence of a thermal process is predicted by a practical computer simulation technique involving a novel empirical function. The predicted oxygen precipitation behavior agrees with the corresponding experimental results reasonably well. (ii) For a systematic description of Fe segregation gettering, explicit expressions of the Fe segregation coefficients are obtained as functions of temperature and time. Using the determined expressions of the segregation coefficients and introducing diffusion dynamics, one can predict [Fe] behavior as a function of process time during a whole sequence of a thermal process. For both behaviors of(i) oxygen precipitation and (ii) segregation induced gettering, experimentally observed characteristics of a high-temperature process and a low-temperature process are well understood by aids of those simulations. (iii) For a high-sensitivity detection of an important heavy metal impurity Cu, we present a novel bulk impurity collection technique using a room-temperature Cu drift phenomenon accelerated by Corona charge showering on a Si wafer surface