Process for controlling thermal history of czochralski-grown silicon

摘要

A process is described for controlling the thermal history of a single crystal silicon ingot (26) during a crystal growth process in which the silicon ingot (26) is rotated and pulled from a silicon melt (16) contained within a rotating crucible (12) in accordance with the Czochralski technique. The ingot (26) has, in succession, a cone (28), a main body (29) having a first half and a second half, and an end-cone (30). The process is characterized in that the second half of the main body (29) of the ingot (26) is pulled from the silicon melt (16) at an average rate which does not exceed about 0.6 mm/min. and the end-cone (30) of the ingot (26) is pulled from the silicon melt (16) at a rate which does not exceed 0.6 mm/min. during the first half of the length of the end-cone (30).