Validation of a 3D mathematical model for feed rod melting during floating zone Si crystal growth

•The shape of the open melting front in FZ growth was calculated with a 3D model.•Inductor current supplies create a local shape asymmetry of 0.6 mm.•Numerical results were confirmed by in situ and ex-situ shape measurements. A mathematical model of global 3D heat transfer in floating zone silicon single crystal growth process is used to predict the shape of the open melting front of the feed rod. The model is validated using measurement data from research-scale growth experiments. Shape profiles of the open melting front are obtained from the feed rod leftover using a movable dial gauge. Azimuthal asymmetry of the rim of the open melting front is revealed in both simulations and measurements, quantitatively indicating the influence of the main slit of the inductor.