Hard-shaft heavy-load silicon single crystal lifting device

Abstract

The invention provides a hard-shaft heavy-load silicon single crystal lifting device, which comprises a support structure; a single crystal bearing outer hard shaft, wherein a single crystal claw is mounted at the bottom of the single crystal bearing outer hard shaft; a seed crystal bearing inner hard shaft, wherein a seed crystal chuck is mounted at the bottom of the seed crystal bearing inner hard shaft; a rotary driving device used for driving the single crystal bearing outer hard shaft to rotate; an outer hard shaft lifting device used for driving the single crystal bearing outer hard shaft to lift; and an inner hard shaft lifting device used for driving the seed crystal bearing inner hard shaft to lift. Synchronous rotating motion of the inner hard shaft and the outer hard shaft, independent lifting motion of the outer hard shaft and independent lifting motion of the inner hard shaft are achieved; the device has high strength and rigidity, can bear single crystals with the weightof 500 Kg or above, makes up the defect of insufficient bearing capacity of the flexible shaft lifting device, avoids the phenomena of flexible shaft swinging and simple pendulum resonance in the flexible shaft lifting device, and can overcome crystal disturbance caused by thermal field symmetry deviation, airflow excitation acting force symmetry deviation and the like.

Description

technical field [0001] The invention relates to a crystal pulling device in a large-size, heavy-weight photovoltaic-grade or electronic-grade silicon single crystal Czochralski method growth furnace, in particular to a crystal pulling device with high precision in pulling and guiding, small single crystal disturbance, and crystal intrinsic quality and A hard-shaft heavy-load silicon single crystal pulling device with high external crystal quality and large bearing capacity, especially a hard-shaft heavy-load silicon single crystal pulling device. Background technique [0002] Silicon single crystal is the basic material for photovoltaic cells and the semiconductor industry. More than 90% of photovoltaic cells and more than 95% of semiconductor devices use silicon-based substrates. Among them, Czochralski silicon single crystal technology is highly mature and occupies the main market. Based on the production efficiency and cost reduction of photovoltaic cells and semiconducto...

AI Technical Summary

Problems solved by technology

When the crystal is disturbed, the ADC (Auto Diameter Control) control system that monitors the crystal growth diameter will not be able to accurately monitor the diameter, resulting in abnormal feedback signals, and the pulling speed fluctuates periodically with the disturbance; the disturbance will cause the microscopic diffusion layer at the moment of growth. Changes, resulting in changes in the effective segregation coefficient, resulting in radial inhomogeneity in the distribution of microscopic dopant concentrations; disturbances can also cause instability in melt convection, resulting in changes in the undercooling of the solid-liquid interface during growth, which is called dendrites. The growth provides conditions; at the same time, as the crystal is pulled upwards and the length of the flexible shaft of the tungsten wire rope decreases, the system resonance frequency of the pulling device is constantly changing, which is easy to cause the crystal and the pulling device to resonate

Therefore, crystal disturbance will adversely affect the internal quality of the crystal such as resistivity and crystal micro-defects, the external shape of the single crystal, and the stability of crystal growth.

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