Czochralski Silicon Crystal Puller (2D)

A 2D cross-section of the same real Czochralski process: a seed crystal dips into a molten silicon crucible and is slowly withdrawn while rotating, freezing melt onto its tip layer by layer. Pull rate and melt temperature feed a simplified heat/mass-balance formula each frame that computes the crystal's target diameter — pull faster or cool the melt and the boule narrows, pull slower or heat the melt and it widens, just like a real puller's diameter-control loop. The same balance sets the Voronkov ratio between pull rate and interface thermal gradient; when it strays too far from the safe band, dislocation-risk bands are flagged directly on the growing boule. Tune pull rate, melt temperature and rotation and read diameter, grown length and gradient live.