Silicon rod manufacturing method capable of reducing silicon rod concentric circles

Abstract

The invention discloses a silicon rod manufacturing method capable of reducing silicon rod concentric circles. The silicon rod manufacturing method comprises material melting, crucible rotation, neck craning, shouldering, shoulder turning, equal diameter treatment and ending. In the crucible rotation, a crucible rotation rate is in a range of 8-10r / min. In the shouldering, a lifting rate is in a range of 0.8-1.0mm / min and a crucible rotation rate is in a range of 8-10r / min. In the shoulder turning, a lifting rate is in a range of 1.6-1.8mm / min and a crucible rotation rate is in a range of 8-10r / min. In the equal diameter treatment, a crucible rotation rate is in a range of 8-10r / min. In the ending, a crucible rotation rate is in a range of 8-10r / min. The doping agents are rotated at a high rate so that a concentration is uniform, alloy density distribution is uniform, dislocated mono-crystals are reduced, and a crystal lifting rate in shouldering is increased so that a shouldering crystallization speed is greatly reduced and the mono-crystals can stably grow after shoulder turning and thus speed fulctuation is reduced. A crystal lifting rate in shoulder turning is reduced so that diameter and temperature fluctuation in shoulder turning are greatly reduced and thus mono-crystal dislocation probability is reduced.

Description

technical field [0001] The invention relates to a process method for improving the quality of a single crystal in the crystal pulling process of single crystal silicon production, in particular to a method for manufacturing a silicon rod that reduces the concentric circle of the silicon rod. Background technique [0002] The production of single crystal silicon generally needs to be produced by a single crystal furnace. The single crystal furnace is equipped with a quartz crucible and a heating system. The main body of the heating system is a heater. The height of the heating area directly affects the quality of the single crystal crystal, and the quartz crucible Placed on the crucible holder matched with the rotating mechanism, it can be rotated. At present, the height of the heater is generally not up to the requirements due to the space limitation of the thermal field, which causes single crystal dislocations to easily appear, resulting in single crystal stuck edges, sing...

AI Technical Summary

Problems solved by technology

[0003] At present, after monocrystalline silicon is grown by the Cz method and melted from polycrystalline silicon solid to liquid at high temperature, boron, the dopant added to the silicon melt, must be completely melted into it. Due to the influence of the viscosity of the silicon liquid, it will cause excessive silicon The doping concentration is different, which increases the probability of single crystal dislocation during crystal pulling

[0004] In the existing manufacturing process, the pulling speed of single crystal is 0.7mm / min during the shoulder laying process, and 2.0mm / min when turning the shoulder. Due to the unscientific pulling speed, the temperature and diameter fluctuate too much, resulting in single crystal bit The probability of dislocation increases, and due to the increase of dislocation density, it becomes a strong recombination center for minority carriers, which eventually leads to a serious decline in battery performance.

During the EL test of the cell, there will be a complete concentric black area in the middle. In the black center area, the minority carrier lifetime is obviously low and the conversion efficiency is extremely low. How to solve the large number of inefficiencies (concentric circles, Black chip) silicon wafer problem is a major problem that monocrystalline silicon production enterprises urgently need to solve