Method for measuring double-camera straight-pulling monocrystal diameter based on digital signal processor

Abstract

The invention discloses a two-camera diameter measurement method for Czochralski crystal based on a digital signal processor, which comprises a plurality of steps: collect the image at the stages of crystal growth and equi-diameter by adopting standard industrial double CCD camera; carry on the processes of edge detection, noise removal, data fitting, data filtering and data compression for the image information by utilizing a core processor with embedded structure based on DSP to realize the precise measurement on the diameter of monocrystalline silicon rod; finally, communicate the measurement radius and compressed image information with a host computer through the Ethernet interface and TCP / IP protocol. The two-camera diameter measurement method for Czochralski crystal based on a digital signal processor has the advantages that by utilizing the core processor with embedded structure, the measurement method has high reliability and no host machine resources are occupied; by adoptingstandard industrial double CCD camera to process the diameters at different stages respectively, the measurement method has high accuracy and low cost; by adopting the techniques of complex edge detection, noise removal, least squares fitting, extreme value filtering, data compression and algorithm level optimization, the measurement method has strong function, high accuracy and fast speed.

Description

technical field [0001] The invention belongs to the technical field of image detection, and relates to a method for measuring the diameter of a silicon rod when the Czochralski method is used to produce single crystal silicon, in particular to an image measurement method based on dual cameras and a digital signal processor. Background technique [0002] Silicon single crystal is the "grain" of semiconductor industry and solar energy industry. At present, the Czochralski method is the main method for manufacturing silicon single crystal. The Czochralski method (CZ method) is to heat and melt a polycrystalline silicon block in a quartz crucible, and maintain a specific high temperature and negative pressure environment. Immerse a rod-shaped seed crystal (called a seed crystal) with a diameter of only 10 mm into the melt solution. At a suitable temperature, the silicon atoms in the melt solution will form regular crystals on the solid-liquid interface along the silicon atom arr...

AI Technical Summary

Problems solved by technology

However, the price of the high-resolution camera and its matching image processing card is relatively high, and it is still necessary to add an image processing card (or use a separate computer) to the host computer, occupying the resources of the host computer, and the cost of the entire system is still very high

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