Growth Angle and Melt Meniscus of the RF-heated Floating Zone in Silicon Crystal Growth

This article presents a direct measurement of the growth angle during the growth of a cylindrical 2" silicon crystal using a radio-frequency heated floating zone process. From the high-resolution pictures taken during the process, this growth angle was evaluated to be 11{\deg}{\pm}2{\deg}. Furthermore, the free surface of the melt was modeled using the Laplace-Young equation. This model has to include the electromagnetic pressure calculated by the surface ring currents approximation. The results were compared to the experimental free surface derived from video frames. It could be shown that the calculated free surface will only fit the experimentally determined one if the right growth angle is considered

AUTOMATION OF CHOKHRALSKY'S PROCEDURE WITH USING MATHEMATICAL MODELS OF SMALL QUANTITY DIMENSION

The work covers the methods for growing of the crystals from melt with use of the capillary forming. The aim is to create the scientific bases for design of the optimum digital automatic control systems and their modifications by Chokhralsky's procedure, to develop the new check and control systems of the pulled crystal diameter. The principles have been formulated, the base models of small quantity dimensions have been proposed for designing the optimum multichannel digital automatic control systems of the basic industrial crystal growing procedures, the weigh check theory at crystallization has been developed. The two-channel optimum control systems of diameter for the crystals pulled by Chokhralsky's method and from under flux, new types of the automatic force-balance transducers and new methods for determination of the capillary content and melt densities and also of noise filtration have been developed. The control programs are used in the industrial output of lithium niobate crystalsAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio