3. For Si wafer production the concentrations of Cu should be below 300ppt. The wafers are cut from a 1.8m long Si single crystal grown by the Czochralski technique starting with polycrystalline Si containing 1ppmCu. Using an effective segregation coefficient of 0.00001, calculate the Cu concentration profiles along the single crystal for positions every 10cm until 1.50m. What portion of the single crystal can be used for wafer production? What would be the portion of the single crystal that could be used if it were grown with a one pass float zone process when the length of the float zone is 2cm. Comment on the purification potential of the float zone process as compared to the Czochralski technique. Which of these two crystal growth processes would you employ to reach better purification levels? Data Error function Note: When x