In the field of SiC single crystal growth (PVT method), the quality of the raw material directly determines the yield of the substrate. Traditional Acheson-method abrasives are difficult to purify and possess small particle sizes, making them increasingly inadequate for 8-inch and semi-insulating crystal requirements.
1. Laboratory Data: The Leap from 5N to 7N
The GDMS (Glow Discharge Mass Spectrometry) report (see PDF Page 4) confirms:
| Metric | Measured Value |
| Total Purity | 99.9999950% (7N) |
| Key Metal Impurities (Ti, V, Fe, Ni) | < 0.01 ppm wt |
| Nitrogen Concentration (SIMS) | N conc.=4.98x1015[atom/cm3](500~1500nm) |
Our nitrogen levels are significantly superior to conventional purified materials, which is critical for semi-insulating crystal growth.
2. Physical Specifications: Large Grain Size = High Yield
Traditional Acheson materials typically have grain sizes < 2.5mm, which can lead to premature graphitization.
| Parameter | Our CVD High-Purity Granules | Traditional Material |
| Average Grain Size | 4–10mm (Up to tens of mm) | < 2.5mm |
| Crucible Loading | > 1.5kg (Per standard volume) | ≤ 1.0kg |
| Material Utilization | > 50% | ~30% |
| Ingot Output | 3.5kg ingot from 4.5kg material | — |
This data proves that our material solves supply shortages for large-size crystal growth and reduces carbon inclusion defects.
3. Academic Support: Si/C Molar Ratio vs. Micropipes
Experts from the Shanghai Institute of Ceramics (SICCAS) , such as Chen Zhizhan and Shi Erwei, have noted:
● Inconsistency in Si/C evaporation and phase transformation is a primary cause of micropipe defects.
● CVD Process: Our Si/C molar ratio is closer to the theoretical 1:1 compared to self-propagating methods.
● Defect Reduction: This balance minimizes defects induced by high Si partial pressure.
● Prototype Retention: CVD granules maintain their prototype after use, reducing recrystallization and impurity enrichment.
4. Crystal Growth Comparison: Traditional vs. CVD High-Purity
● Traditional Material: Often results in visible carbon inclusions, micropipes, and uneven light transmission.
● CVD High-Purity Material: Produces ingots with high optical uniformity, significantly lower defect density, and improved structural integrity.
5. Engineering Conclusion
Materials change the future; we provide the "strategic grain" for the semiconductor industry.
Our CVD process achieves 7N purity combined with 4–10mm grain size control.
Automated workflows reduce human error and ensure high batch-to-batch consistency.
This product fills a critical domestic gap, optimized for 8-inch and semi-insulating SiC crystal growth.
SIMS Nitrogen Depth Profile:
Ingot Comparison: Side-by-side view of crystals showing the superior clarity of those grown with CVD material
Founded in 2018, Semixlab Technology Co.,Ltd is a technology-based enterprise focusing on the research and development, production and sales of advanced materials. It is a world-leading semiconductor material manufacturer.
