Production method of high purity cured charcoal felt silicon crystal growth oven

Abstract

The invention discloses a making method of high-purity solidified carbon cushion in the silicon crystal growing stove, which is characterized by the following: selecting flexible cushion with low metal impurity as blank material; disposing under high temperature to form graphite cushion; using graphite cushion as blank; solidifying the blank to shape with evenly permeable hardener; carbonizing the blank; proceeding chemical gas-phase deposition for blank; cutting part of element surface mechanically; disposing blank under high temperature; removing metal impurity and volatile substance; coating the working piece; strengthening the element surface; improving the corrosion resistant of blank surface.

Description

technical field [0001] The invention relates to a method for preparing heat-insulating parts for a silicon crystal growth furnace, in particular to a method for manufacturing a high-purity solidified carbon felt for a silicon crystal growth furnace. Background technique [0002] The working temperature of the silicon crystal growth furnace is above 1500°C. The thermal field system of the silicon crystal furnace has a great influence on the crystallization conditions of silicon crystals, the integrity of semiconductor silicon crystals, that is, the performance of silicon wafers. Therefore, the design of the thermal field system, the selection and use of materials for various components in the thermal field have received extensive attention. Since the early 1990s, it has been proposed to use carbon-carbon composite materials to make thermal field parts. German SGL Carbon Composite Material Co., Ltd. introduced the purification of silicon crystal growth furnace parts with car...

AI Technical Summary

Problems solved by technology

The disadvantages of doing this: 1) Since many impurities are volatilized in the molten polysilicon, these volatiles are deposited on the furnace top, furnace bottom, heaters in the furnace, graphite sleeves, and also on the insulation soft carbon felt. superior

The impurities deposited on dense objects such as graphite can be cleaned up after each shutdown; the soft carbon felt itself is like a vacuum cleaner, and the impurities deposited on the soft carbon felt cannot be cleaned; the remaining pollutants may be removed at any time Pollution of the polysilicon melt makes it difficult to form crystals; 2) Many graphite parts are used as supports in the thermal system. Graphite is brittle, and its processing technology must be considered during design. To ensure strength, the wall thickness of graphite parts cannot be made Too thin, so the weight is heavy; it occupies space; the brittle and bulky thermal field parts bring inconvenience to operation and use

3) Graphite is a good conductor of heat. The proportion of graphite parts in the thermal field system is large, and the heat derived from the furnace body is more, which reduces the thermal insulation performance of the system

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