Czochralski germanium single crystal diameter measurement and control system

Abstract

A measurement control system for diameter of Czochralski grown monocrystalline germanium is characterized by comprising a camera, an image processor and an automatic control unit, the camera acquires images of equal-diameter growth of monocrystalline germanium, an image processor recognizes the position of an aperture of a solid-liquid interface and calculates curvature radius of the aperture of the solid-liquid interface to allow for equal-diameter growth of monocrystalline germanium by the automatic control unit. The measurement control system for diameter of Czochralski grown monocrystalline germanium has the advantages that an image processing card only analyzes an aperture part of acquired images, data transmission quantity is reduced, and the requirement of the system for hardware performance is reduced. Complex mapping from ellipse to circle is not required, and equal-diameter control can be achieved according to a change rule of the curvature radius only by acquiring the curvature radius of a specified point. The camera can integrally transmit the acquired growth images of monocrystalline germanium for image processing and analyzing, and accordingly multiple devices are convenient to monitor in real time by a production operator and labor strength of growth of monocrystalline germanium is lowered. The existing devices can be utilized to the maximum limit, and repeated design and investment of an electrical control system are avoided.

Description

technical field [0001] The invention belongs to the technical field of on-line control of the single crystal diameter based on an embedded system in the Czochralski single crystal process. Background technique [0002] Germanium single crystal is an important material in the infrared field and semiconductor industry. At present, the Czochralski method (Czochralski, CZ method) is an important method for manufacturing germanium single crystal. In this method, by designing a reasonable thermal field, the polycrystalline germanium material is put into the crucible, and a certain temperature and pressure environment are maintained. Immerse the seed crystal in the solution, and in a suitable thermal field environment, the germanium atoms in the solution will continue to arrange along the original germanium atom arrangement structure of the seed crystal at the solid-liquid interface between the seed crystal and the melt, and slowly lift the seed crystal , then a single crystal con...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the deficiency that the existing Czochralski single crystal diameter control system cannot detect the aperture signal of the germanium-solid-liquid interface using an Ircon probe, resulting in the inability to use an automatic control unit to automatically control the equal-diameter growth of germanium, the invention provides a Czochralski germanium The single crystal diameter control system can detect the change of diameter during the growth process of germanium single crystal, and realize the automatic control of the equal diameter growth process of germanium single crystal

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