Silicon single crystal Czochralski growth process

摘要

In a Czochralski process for producing a ordering defect-free silicon single crystal without resorting to neck formation, the novelty is that: (a) the maximum horizontal length of the seed portion immersed in the silicon melt at the moment of complete immersion is = 5 mm; (b) optionally the immersed seed portion is shaped by machining; and (c) at least one of the following conditions is fulfilled: (i) the leading end of the immersed seed portion bulges downwards, (ii) the surface roughness (Rmax) of the immersed seed portion is }5 mu m (based on a reference length of 0.1 mm), (iii) the immersed seed portion has been etched or has been grown preferably by the magnetic field Czochralski (MCZ) method, (iv) the dopant concentration in the seed is = 1*1017 cm-3, (v) the seed immersion velocity is }2.8 mm/min. and (vi) the temperature gradient in the seed during crystal growth is }10 deg C/mm.