Method for growing low-imperfection-density direct-drawing silicon monocrystal in magnetic field

Abstract

The method for growing a Czochralski silicon single crystal with low defect density disclosed by the present invention has the following steps: put polysilicon into a quartz crucible, and dope germanium with a purity greater than 99.999%, under a magnetic field strength of 100-10000G and a protective gas , raise the temperature to 1400°C~1450°C to melt germanium into the polysilicon melt, and the doping concentration of germanium in single crystal silicon is 1×10 10 -1×10 21 cm -3 , Czochralski silicon single crystal with low defect density was grown. The invention adopts the growth of Czochralski silicon single crystal under the magnetic field, and can effectively control and reduce the concentration of oxygen by adjusting the magnetic field strength, and utilizes the doping of a small amount of germanium to make germanium interact with point defects, thereby suppressing the original micro-defects in the silicon single crystal, In particular, the generation of VOID defects reduces the defect density, which is conducive to increasing the growth rate, reducing costs, and growing high-quality silicon single crystals.

Description

technical field [0001] The invention relates to a method for growing a Czochralski silicon single crystal. Background technique [0002] In order to reduce costs, the diameter of Czochralski silicon single crystals used in VLSI is getting larger and larger, and with the improvement of technology, the characteristic line width of VLSI is gradually becoming smaller. Therefore, silicon single crystals used in VLSI The development direction of the crystal is that the diameter becomes larger, and the defect size and density become smaller. As the diameter of Czochralski silicon single crystal increases, factors such as crystal flow and other factors change greatly during crystal growth, which directly affects the properties of the main impurity oxygen and other micro-defects in silicon crystals. [0003] The growth technology of Czochralski silicon single crystal has been mature. For example, the methods for growing silicon single crystal disclosed in Chi...

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Problems solved by technology

(3) After preparing polished silicon wafers, high-temperature annealing in argon or hydrogen can remove defects near the surface. This method increases cost and process, and increases the possibility of metal contamination