3D Simulation of the Coil Geometry Effect on the Induction Heating Process in Czochralski Crystal Growth System

Abstract

Herein, influence of coil geometry in a Czochralski crystal growth system is studied using 3D finite element method. Three different geometries for the helical RF‐coil including solenoid, conical solenoid, and rectangular are considered and distribution of magnetic flux density (through the system), produced heat in the RF‐coil and the graphite crucible, as well as heat volume integral are calculated. The obtained numerical results show that every considered coil produces a special heating structure due to its shape with some advantages and disadvantages.

Model experiments for Czochralski crystal growth processes using inductive and resistive heating

“…To give a better comparison to a 2D simulation, the idealized symmetric distribution is indicated. Comparison of the two lines indicates a strong 3D character, as observed also in [4], thus the accuracy of a 2D simulation is limited. The asymmetric magnetic field is assumed to be caused by the influence of the current supplies at one side of the coil and by the spiral shape of the windings; further investigation using both additional measurements and 3D simulations are under preparation.…”

“…Both induction heating [3,4] and graphite resistance heaters [5,6] are applied in the CZ growth technique, selected based on various requirements such as cost efficiency, electromagnetic forces, or degree of purity inside the furnace. Numerical simulations have been applied for investigation of both concepts [4,6].…”

“…Both induction heating [3,4] and graphite resistance heaters [5,6] are applied in the CZ growth technique, selected based on various requirements such as cost efficiency, electromagnetic forces, or degree of purity inside the furnace. Numerical simulations have been applied for investigation of both concepts [4,6]. However, due to various simplifications in the numerical models as well as due to often uncertain or unknown material properties, validation is required to give reliable simulation results [7].…”

Numerical and experimental analysis of heat transfer in inductive conduction based wire metal deposition process

“…Since, in the helical part, on increasing the turn radius the heat intensity decreases due to the variation in magnetic flux density concentration. 32 In contrast, the magnetic flux density in the surrounding of the extreme loop of the coil is comparatively higher than the inner loops of the coil. With a spiral-helical coil configuration, the higher temperature at the lower bottom of extruder is concentrated.…”

“…Later, the induction heat uniformly heats the extruder surface and the heat is conducted towards the centre of the extruder due to the nature of the material (thermal conductivity). 31,32 The underlying process can be understood by coupling the above two stated physics using numerical computation. Here, the electromagnetic analysis is performed by solving Maxwell equations with constitutive relations and appropriate boundary conditions, whereas the thermal field model solves the heat transfer equations as described below.…”