Semiconductor-level quartz crucible and production method thereof

Abstract

The invention relates to a semiconductor-level quartz crucible and a production method thereof. The semiconductor-level quartz crucible is prepared from high-purity quartz sand with higher purity andlow impurity content, efficient isolating quartz sand and high-purity synthetic amorphous quartz sand according to the steps of raw material preparation, charging, material molding preparation, material molding, melting preparation, melting and post-processing, in the manner of generating a first protecting layer on the surface of a quartz crucible main body and generating a second protecting layer and a third protecting layer on the first protecting layer. The semiconductor quartz crucible comprises the quartz crucible main body, the first protecting layer, the second protecting layer and thethird protecting layer, wherein the first protecting layer is thicker than a micro-bubble layer in the prior art; the shaking of a silicon liquid level caused by the micro-bubbles is reduced by the second protecting layer; the third protecting layer is used for preventing a semiconductor silicon bar from crystallizing during a crystal pulling process, realizing the production of the semiconductorsilicon bar with the quartz crucible, obviously reducing the crystallizing defect of the semiconductor-level silicon bar, reducing the times of seeding and guaranteeing no crystallizing during the crystal pulling process.

Description

technical field [0001] The invention relates to the field of crucible production, in particular to a semiconductor grade quartz crucible and a manufacturing method thereof. Background technique [0002] Quartz crucible is an important accessory for pulling single crystal silicon rods, and is usually used to produce conventional crystal rods. [0003] Quartz crucibles usually use natural quartz sand (SiO 2 content is 99.99%), there are certain gaps between the quartz sand particles, in the production process of the quartz crucible, even under the reaction conditions of vacuum and 1700 ℃, it is difficult to remove the air in the gaps between the quartz sand particles, some The molten quartz will wrap the surrounding unmelted quartz sand and form gas-liquid inclusions of quartz sand, which eventually leads to a high content of microbubbles on the inner surface of the quartz crucible. Within 1 mm depth of the inner surface of the crucible. During the growth process of single ...

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Problems solved by technology

During the growth process of single crystal silicon rods, the microbubbles in the quartz crucible slowly expand and grow up under the continuous high temperature environment, and merge into larger microbubbles. Once broken, quartz fragments and impurities will be brought into the molten silicon In the liquid, the degree of reaction between the quartz crucible and the molten silicon liquid is aggravated, causing the silicon liquid level at the liquid level line inside the quartz crucible to shake, resulting in failure or disconnection of the crystal during the crystal pulling process.

[0004] Quartz crucible contains more impurities, the total impurity content is close to 100ppm, especially metal ions such as potassium, sodium, calcium, magnesium, aluminum, etc., and the thermal field temperature during the whole crystal pulling process is as high as 1700°C, resulting in potassium, sodium, calcium, The chemical activity of metal ions such as magnesium and aluminum is relatively high, and metal ions such as potassium, sodium, calcium, magnesium, and aluminum are easy to chemically react with the inner surface of the quartz crucible, and a layer of devitrification layer is formed on the inner surface of the quartz crucible. With the prolongation of time, the crystallization layer gradually becomes thicker, resulting in abnormal changes in the growing crystal structure and unable to grow normally or ideally, resulting in increased crystal defects in the growing crystal rod

[0005] In the prior art, although a composite layer is provided on the surface of the quartz crucible, there are still many microbubbles and impurities in the quartz crucible itself and the composite layer, so that the quartz crucible cannot meet the production requirements of semiconductor-grade ingots.

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