Silicon ingot having uniform multiple dopants and method and apparatus for producing same

A method of Czochralski growth of a silicon ingot comprising a dopant material in a concentration C and having a segregation coefficient of k, the method comprising the steps of:

• i) providing a crucible having an inner growth zone in fluid communication with an outer feed zone;
• ii) pre-charging the inner growth zone with silicon and the dopant material to form a mixture, wherein the mixture, when melted, has a concentration of the dopant material of C/k, where k is less than 1, and pre-charging the outer feed zone with silicon and the dopant material in a concentration C, when melted,
• iii) melting the mixture in the inner growth zone and the silicon and the dopant material in the outer feed zone;
• iv) initiating growth of the silicon ingot from the inner growth zone;
• v) delivering a feed of silicon and the dopant material into the outer feed zone while growing the silicon ingot, the feed having an average concentration of the dopant material C when melted;
• and
• vi) removing the silicon ingot comprising the dopant material in concentration C.