Effect of Magnetic Field Strength on the Uniformity of COP Defects in 12 Inch Cz Monocrystalline Silicon

doi:10.16553/j.cnki.issn1000-985x.2025.0130

Abstract

Abstract: In semiconductor manufacturing， monocrystalline silicon grown by Czochralski （Cz） method serves as the core substrate for microelectronic devices， with its crystal integrity and defect distribution being crucial for chip yield and reliability. However， the issue of non-uniform radial distribution of crystal originated particle （COP） defects during the Cz growth process urgently needs to be addressed. This paper investigates， through numerical simulations and experimental research， the effects of different transverse magnetic field strengths （500 and 3 000 Gs） on melt convection， melt temperature distribution， and the temperature gradient at the solid-liquid interface during the pulling of 12 inch （1 inch=2.54 cm） Cz monocrystalline silicon. It also analyzes the mechanism by which magnetic field strength influences the uniformity of COP distribution. The results indicate that under a 3 000 Gs magnetic field， the melt flow， temperature distribution， and the temperature gradient at the solid-liquid interface are more stable， facilitating the formation of a low-density and uniform COP distribution. In contrast， under a 500 Gs magnetic field strength， the COP distribution throughout the silicon ingot exhibits high density and non-uniformity. The experimental results are consistent with the numerical simulations， verifying the significant impact of magnetic field strength on the uniformity of COP distribution. This study provides a theoretical basis and practical guidance for optimizing the Cz monocrystalline silicon growth process and improving crystal quality.

Key words: monocrystalline silicon; semiconductor; magnetic field strength; Czochralski method; COP; uniformity

CLC Number:

O782

WANG Zhongbao, ZHANG Youhai, LIU Tianpei, NI Haoran, RUI Yang, MA Cheng, WANG Liguang, CAO Qigang, YANG Shaolin. Effect of Magnetic Field Strength on the Uniformity of COP Defects in 12 Inch Cz Monocrystalline Silicon[J]. Journal of Synthetic Crystals, 2025, 54(12): 2101-2111.

Figures/Tables 14

Fig.1 Thermal field structure diagram and corresponding grid diagram for single crystal simulation

Table 1 Crystal growth parameters used in simulations and experiment

Parameter	Value	Unit
Body length	2 100	mm
Pulling rate	0.5	mm/min
Crystal rotation	8	r/min
Crucible rotation	1.5	r/min
Diameter	308	mm
Liquid port distance	80	mm
Furnace pressure	7	Torr
Ar flow rate	100	L/min
Magnetic center position	40	mm

Table 2 Physical properties of material in crystallizing simulation

Material	Heat capacity/（J·K^-1·kg^-1）	Heat conductivity/（W·K^-1·m^-1）	Emissivity	Density/（kg·m^-3）
Si （melt）	975	66.5 3.28×10⁵×T-1.341 0	0.33	2 520
Si （crystal）	715		0.60	2 330
Quartz crucible	1 100		0.85	2 200
Graphite	1 650	122	0.80	1 750
Graphite felt	1 800	0.3	0.86	140
Stainless steel	500	30	0.38	7 930

Fig.2 Melt flow field diagrams （top） and corresponding flow velocity direction vector diagram （bottom） when the crystal pulling length is 200 mm

Fig.3 Melt flow field diagrams when the crystal pulling length is 1 400 mm

Fig.4 Melt flow field diagrams when the crystal pulling length is 2 000 mm

Fig.5 Melt temperature distribution diagrams when the crystal pulling length is 200 mm

Fig.6 Melt temperature distribution diagrams when the crystal pulling length is 1 400 mm

Fig.7 Melt temperature distribution diagrams when the crystal pulling length is 2 000 mm

Fig.8 Variation of G/Gc at the solid-liquid interface with radial position when the crystal pulling length is 200 mm

Fig.9 Variation of G/Gc at the solid-liquid interface with radial position when the crystal pulling length is 1 400 mm

Fig.10 Variation of G/Gc at the solid-liquid interface with radial position when the crystal pulling length is 2 000 mm

Fig.11 COP distribution maps of silicon wafers cut from the silicon rod at 200 mm （a）， 1 400 mm （b）， and 2 000 mm （c） of the constant diameter under a magnetic field strength of 3 000 Gs

Fig.12 COP distribution maps of silicon wafers cut from the silicon rod at 200 mm （a）， 1 400 mm （b）， and 2 000 mm （c） of the constant diameter under a magnetic field strength of 500 Gs

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