Dislocation-suppressed Czochralski Si crystal growth with high interstitial oxygen Si seed

In the production of monocrystalline silicon ingots with Czochralski (CZ) method, silicon seeds largely determine pulling success rate and the weight baring capacity of the dash necks. In this study, high-interstitial oxygen (HO) content silicon seeds were applied to CZ single-crystal growth to enhance mechanical robustness and suppress dislocation formation during 10-inch ingot production. Photoluminescence (PL), microscopic, and 3D X-Ray CT analyses revealed that HO seeds exhibited significantly fewer dislocations and microdefects after the seeding process compared to common seeds, confirming their superior resistance to thermal shock. 0.059° left shift in X-Ray Diffraction (XRD) pattern peak indicates oxygen can cause lattice expansion. Mechanical simulations and Vickers hardness indentation test indicated that interstitial oxygen increases lattice rigidity via a pinning effect, improving toughness (KIC increased 8.8%) despite reduced thermal conductivity (thermal stress increased 1.4%). Four-point bending tests further demonstrated that as interstitial oxygen concentration increased from 8 to 16 ppma, bending and shear strengths rose by 11.6% and 11.1%, respectively. During the necking process, oxygen content in HO seeds rapidly decreased from 17.56 ppma to 3.87 ppma within 10 mm, enabling earlier neck thinning without affecting the head oxygen level of the ingot. In industrial-scale experiments, 10-inch ingots grown from HO seeds achieved crystallization rates of 85–87%—roughly twice those obtained with common seeds—and a 4.3% average increase in output yield, which can bring over 80,000 USD benefit for 1 GW brick production. Furthermore, a 3800 mm-long, 10-inch ingot with a 6.72 mm neck was successfully grown using HO seeds, demonstrating their strong dislocation-suppression capability and potential for high-yield, large-scale stable CZ silicon production.