Double-layer crucible used for Czochralski silicon single crystal growth

Abstract

The invention discloses a double-layer crucible used for Czochralski silicon single crystal growth. The double-layer crucible comprises a crucible, a crucible inner ring and dog-holes, wherein the crucible inner ring is arranged at the center inside the crucible, four symmetrically distributed dog-holes are arranged at the contact position of the lower end of the crucible inner ring and the bottom of the crucible, the diameter of the dog-holes is 10-20 mm, the crucible inner ring is coaxial to the crucible, the thickness of the walls of the crucible and the crucible inner ring is 8-12 mm, the ratio of the outside diameter d of the crucible inner ring to the outside diameter D of the crucible is 0.5-0.7, and the ratio of the height h2 of the crucible inner ring to the height h1 of the crucible is 0.6-0.8; and the crucible and crucible inner ring are made from the material of quartz glass, silicon nitride ceramic or silicon carbide ceramic. The double-layer crucible can effectively inhibit heat convection of silicon melt in a silicon single crystal growth process, substitutes for the action of an electromagnetic field, is simple and energy-saving, and can effectively reduce erosion speed of a quartz crucible, improve temperature stability of the center region on the surface of the silicon melt, and reduce oxygen concentration in silicon single crystal.

Description

technical field [0001] The invention relates to the growth of Czochralski silicon single crystal, in particular to a double-layer crucible for the growth of Czochralski silicon single crystal. Background technique [0002] The Czochralski silicon single crystal growth furnace needs to use a quartz crucible to melt polycrystalline silicon. Usually, a quartz crucible is selected according to the diameter of the silicon single crystal to be grown. Now the commonly used outer diameters are 18 inches, 20 inches, 22 inches, 24 inches, and 28 inches. inch, 32 inch quartz crucible. The shape of the quartz crucible is a cylinder with an open top and a bottom bottom. [0003] When growing a silicon single crystal in a Czochralski silicon single crystal furnace, there is heat convection of the melt in the quartz crucible, and the heat convection rises along the crucible wall and flows to the central area of ​​the crucible under the surface of the melt. Thermal convection has a strong...

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However, the electromagnetic field consumes a lot o

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