SiC Vertical Boats

Semicorex SiC Vertical Boats are engineered wafer carriers, designed and manufactured to provide the highest thermal, mechanical, and chemical stability for vertical furnace semiconductor processing. Constructed of high-purity silicon carbide, we believe that they are the best balance of strength, durability, and cleanliness for very advanced wafer thermal processing, noted as oxidation, diffusion, LPCVD, and annealing in vertical furnace systems.

The vertical furnace processing environments require a wafer support system that can withstand repeated exposures at high temperature, often exceeding 1,200°C, and remain dimen-sionally stable without contamination issues. SiC Vertical Boats excel in their robustness in these situations because of the intrinsic mechanical and thermal properties of recrystallized or CVD silicon carbide. Their extremely low thermal expansion coefficient ensures minimal warpage or distortion due to rapid thermal cycling. Additionally, the high thermal conductivity, offers the greatest local temperature homogeneity across all wafers, which is critical for wafer-to-wafer consistency in layer thickness, doping profiles, and electrical performance; important aspects of high-volume manufacturing in the semiconductor industry.

Compared to traditional quartz boats, SiC Vertical Boats deliver superior mechanical strength and extended service life. Quartz tends to become brittle and devitrify over time, particularly in aggressive furnace chemistries, leading to higher replacement costs and potential production interruptions. In contrast, silicon carbide maintains its integrity even after prolonged exposure to corrosive gases such as chlorine, HCl, or ammonia, which are common in various diffusion and LPCVD processes. Its exceptional wear and oxidation resistance greatly reduces particle generation, helping to safeguard wafer surfaces from contamination and defect formation.

SiC Vertical Boats also offer a significant benefit in terms of ultra-clean processing. High-purity SiC material is processed under strict diligence to reduce identifiable trace contaminating metals that can interfere with the operational characteristics of semiconductor devices. SiC Vertical Boat surfaces are well finished with right-angled features that minimize the chance of micro-particles shedding. SiC surfaces are chemically inert and do not react with process gases and are therefore less prone to contamination. In this respect, SiC Vertical Boats are well suited for the front end of line (FEOL) and the back end of line (BEOL) wafer processing operations.

SiC Vertical Boats also offer design flexibility. Each Vertical Boat can be design-specific to accommodate multiple wafer diameters (150 mm, 200 mm or 300 mm wafers) and slot number and spacing can be utilized to meet process requirements. Precision machining and dimensional control allow for proper wafer alignment and wafer support minimizing the likelihood of any micro-scratches or stress cracks during loading, processing and unloading. Also, if superior temperature uniformity and / or less thermal mass is required for a particular process, optimized geometries and slot designs may be incorporated in SiC Vertical Boat configurations, without sacrificing any mechanical properties.

Another advantage is maintenance and operational efficiency. The rigid construction of SiC Vertical Boats reduces replacement time and frequency, thereby minimizing downtime or cost of ownership. The thermal shock resistance of SiC allows for shorter cycles of heating and cooling to deliver higher throughput on production lines. The maintenance or cleaning of SiC Vertical Boats is also very simple; the material can endure most conventional wet or dry cleaning processes common in semiconductor fabs such as chemical cleaning with acids and high-temperature bake-out.

In this modern age of sophisticated semiconductor fabrication where yield improvement, contamination control and stability in the process have all importance, SiC Vertical Boats offer a true technological advantage. They deal well with the physical and chemical challenges of vertical furnace applications and contribute to overall process optimization by delivering wafer integrity, consistent results and longer life of equipment.