Method for producing gas phase heavy phosphorus-doped float zone silicon single crystal

Abstract

The invention relates to a method for producing a gas phase heavy phosphorus-doped float zone silicon single crystal. The method comprises float zone gas phase heavily doping and crystal pulling processes. In the process, a water-cooled electromagnetic copper coil with double waterways is adopted so that the temperature of the coil can be controlled between 10 and 20 DEG C; therefore, the coil is prevented from being damaged by a chemical reaction of phosphorus and the copper coil at a high temperature; and simultaneously the problem of a coil spark caused by thermal ionization of phosphorus impurities near the coil is solved. The gas phase heavy phosphorus-doped float zone silicon single crystal produced by the method has the characteristics of: oxygen content below 1ppm, axial resistivity uniformity of within + / -10 percent and resistivity of 0.002 Ohm.cm, well meets the strict requirement of a transient voltage suppressor (TVS) on a silicon substrate material, and meets the requirement of a TVS device on the silicon substrate material.

Description

technical field [0001] The invention relates to a method for producing silicon single crystal, in particular to a method for producing silicon single crystal in gas-phase re-doped phosphorus zone melting silicon single crystal. Background technique [0002] Heavy doped silicon single crystal, its single crystal resistivity can reach 10 -2 ~10 -3 Ω·cm, mainly used in the manufacture of VLSI switching power supplies, varactor diodes in color TVs, etc., the market prospect is quite broad. At present, almost all methods of producing heavy-doped silicon single crystals use the Czochralski method. The silicon single crystals produced by them may be thermally unstable and reversible in resistivity due to high oxygen content, resulting in Czochralski heavy-doped silicon single crystals. limitations in the associated device fabrication process. If the zone melting method can be used to produce heavily doped phosphorus-silicon single crystal, the oxygen impurity content and axial r...

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Problems solved by technology

Secondly, when the general zone melting gas-doped crystal pulling process is used for heavy-doped phosphorus pulling, the problem of copper coil sparking often occurs. Negative electrode conducts electricity directly

In addition, due to the high temperature of the furnace during the crystal pulling process, the phosphine has been decomposed into phosphorus at the gas inlet pipe of phosphine. doping

Finally, a large number of dislocations often occur in the crystal pulling process of zone melting and redoping with phosphorus, resulting in the failure of crystal formation

Therefore, the existing zone-melted copper coils can no longer normally complete the crystal pulling work of heavily phosphorus-doped silicon single crystals. At the same time, what kind of heavy phosphorus-doped zone melting crystal pulling process is also a technical problem that needs to be overcome.

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