A double-point measurement method and device for the distance between the liquid mouth of a single crystal furnace with the guide tube as a reference

Abstract

The invention discloses a double-point measurement method and device for the liquid mouth distance of a single crystal furnace with a guide tube as a reference. Step 1: use a CCD camera to photograph the bottom end of the guide tube and obtain the parallel position of the guide tube on the liquid surface. Schematic diagram of the projected image; Step 2: Set three measurement lines at equal pixel intervals on the reflection circle of the image diagram; Step 3: Calculate the liquid outlet distance directly by using the three measurement lines obtained and the determined value obtained when the guide tube is installed . Using only three measurement lines and the determined value obtained when the CCD camera is installed to calculate the liquid outlet distance, avoiding the introduction of proportional coefficients and the corresponding points of the selected boundary points in the reflection, and improving the efficiency and accuracy of the liquid outlet distance.

Description

technical field [0001] The present invention relates to the technical field of monocrystalline silicon production, and more specifically, the present invention relates to a method and device for measuring the distance between liquid openings of a single crystal furnace at two points using a draft tube as a reference. Background technique [0002] In the process of Czochralski single crystal, it includes various common processes such as seeding, shouldering, shoulder turning, equal diameter, and finishing. Among them, the seeding, shouldering, and equal diameter all need to accurately control the distance between liquid ports, that is, The distance from the lower edge of the guide tube to the liquid surface of the molten silicon. At present, the image captured by the CCD camera is analyzed and calculated by the method of taking preset coefficients, that is, the image of the lower edge and reflection of the guide tube is captured by the CCD camera, and the ratio is introduced. ...

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Problems solved by technology

[0002] In the process of Czochralski single crystal, it includes various common processes such as seeding, shouldering, shoulder turning, equal diameter, and finishing. Among them, the seeding, shouldering, and equal diameter all need to accurately control the distance between liquid ports, that is, The distance from the lower edge of the guide tube to the liquid surface of the molten silicon. At present, the image captured by the CCD camera is analyzed and calculated by the method of taking preset coefficients, that is, the image of the lower edge and reflection of the guide tube is captured by the CCD camera, and the ratio is introduced. Coefficient, by multiplying the pixel distance and the coefficient, calculate the straight-line distance between the selected boundary point and the reflection point along the lower edge of the guide tube, and then calculate the liquid mouth distance. It is difficult to determine the coefficient of this method, and the selected boundary point is in the reflection It is extremely difficult to find the corresponding point of

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