Abstract: The present invention provides a methods and system for producing semiconductor grade single crystals that are substantially free of undesirable agglomerated defects. A vacancy/interstial (V/I) boundary simulator analyzes various melt-solid interface shapes to predict a corresponding V/I transition curve for each of the various melt-solid interface shapes. A target melt-solid interface shape corresponding to a substantially flat V/I curve is identified for each of a plurality of axial positions along the length of the crystal. Target operating parameters to achieve each of the identified melt-solid interface shapes are stored in a melt-solid interfaced shape profile. A control system is responsive to the stored profile to generate one or more control signals to control one or more output devices such that the melt-solid interfaced shape substantially follows the target shapes as defined by the profile during crystal growth.

Abstract: The present invention relates to a process for preparing a single crystal silicon ingot, as well as to the ingot or wafer resulting therefrom. The process comprises controlling (i) a growth velocity, v, (ii) an average axial temperature gradient, G0, and (iii) a cooling rate of the crystal from solidification to about 750° C., in order to cause the formation of a segment having a first axially symmetric region extending radially inward from the lateral surface of the ingot wherein silicon self-interstitials are the predominant intrinsic point defect, and a second axially symmetric region extending radially inward from the first and toward the central axis of the ingot.

Abstract: A method and apparatus for controlling the quenching rate of a monocrystalline ingot pulled from a melt by adjusting one or more post growth processing parameter. A temperature model generates a temperature profile that represents the surface temperature along the length of the ingot at the instant it is pulled from the melt. A first temperature at a particular location along the length of the crystal is determined from the temperature profile. A temperature sensor senses a second temperature at the same particular location. A PLC calculates a quenching rate of the crystal as a function of the first temperature and the second temperature. The PLC generates an error between a target quenching rate and a calculated quenching rate, and one or more post growth process parameters are adjusted as function of the error signal to optimize the quenching rate.