Nitrogen doping agent feeding device and method and manufacturing system of nitrogen-doped single crystal silicon rod

Abstract

The embodiment of the invention discloses a nitrogen doping agent feeding device and method and a manufacturing system of a nitrogen-doped single crystal silicon rod. The nitrogen doping agent feeding device comprises a bearing pipe with an opening formed in the bottom, wherein the bearing pipe is used for bearing silicon nitride to be molten; a heating device which surrounds the outer side of the bearing pipe and is used for heating the silicon nitride to be molten to enable the silicon nitride to be molten to be completely molten into a silicon nitride melt; a blocking device which is arranged in the bearing tube and can be attached to the bottom of the bearing tube to shield the opening, so that the silicon nitride to be molten is prevented from falling into the quartz crucible from the opening; a gap can be formed between the blocking device and the bottom of the bearing pipe to open the opening, so that the silicon nitride melt drops into the quartz crucible bearing the silicon melt containing boron atoms from the opening; and a lifting mechanism which is used for lifting or descending the blocking device.

Description

technical field [0001] Embodiments of the present invention relate to the field of semiconductor technology, and in particular to a nitrogen dopant feeding device and method, and a manufacturing system for nitrogen-doped single crystal silicon rods. Background technique [0002] Silicon wafers used for the production of semiconductor electronic components such as integrated circuits (Integrated Circuit, IC) are mainly manufactured by slicing single crystal silicon rods drawn by the Czochralski method. The Czochralski method involves melting polysilicon raw material in a crucible made of quartz to obtain a silicon melt, immersing a seed crystal in the silicon melt, and continuously lifting the seed crystal to move away from the surface of the silicon melt, thereby During the movement, single crystal silicon rods are grown at the phase interface. [0003] In the above-mentioned production process, it is very advantageous to produce a dislocation-free, even twin-free and polyc...

AI Technical Summary

Problems solved by technology

[0004] At present, the technology of nitrogen doping generally uses silicon nitride (Si 3 N 4 ) as a nitrogen source, flake or granular silicon nitride material is put into the polysilicon raw material to realize the addition of nitrogen element, but since the melting temperature of silicon nitride (about 1800°C) is higher than the melting point of silicon (1425°C), it needs to be heated and It can be completely melted in the silicon melt after being stabilized at a high temperature (>1600°C) for a period of time, and there should be no unmelted silicon nitride particles in the silicon melt when the single crystal silicon rod is drawn, otherwise the silicon nitride particles It will enter the single crystal silicon rod and cause dislocation in the single crystal silicon rod, which will lead to the scrapping of the single crystal silicon rod product; and too high silicon nitride melt temperature will easily cause the softening of the quartz crucible to increase, resulting in SiO 2 The precipitated oxygen increases, so that it is difficult to control the oxygen content in the drawing process of the single crystal silicon rod, so that the oxygen content at the top of the single crystal silicon rod is high, which affects the product quality of the single crystal silicon rod

[0005] In addition, especially when drawing single crystal silicon rods containing nitrogen doped and other dopants such as boron, too high temperature of silicon melt will cause the volatilization of dopant boron to increase, and more seriously will cause boron atoms to interact with nitrogen Atoms form refractory boron nitride at a high temperature of more than 1600 ° C. This boron nitride substance always exists in the silicon melt, which is easy to cause dislocation, twinning and even polycrystals in single crystal silicon rods, which in turn leads to single crystal silicon Scrapping of stick products

Images