Abstract: As third-generation semiconductors transition toward larger diameters and lower costs, 12-inch sapphire (PSS) and silicon carbide (SiC) substrates have become critical for industry cost reduction. Based on operational data from the TJ3000 diamond wire multi-wire saw, this paper systematically analyzes the process advantages of this equipment in slicing 12-inch hard and brittle materials. Research demonstrates that diamond wire cutting technology, utilizing high wire speed (≥2500 m/min) and constant tension control, effectively addresses challenges such as large-diameter wafer warpage (Warp < 0.1 mm) and edge chipping. The cost per wafer is reduced by approximately 15% compared to traditional slurry cutting, providing reliable equipment support for the mass production of 12-inch semiconductor substrates.

Keywords: 12-Inch; Diamond Wire Multi-Wire Saw; Sapphire Substrate; Silicon Carbide (SiC) Substrate; Slicing Process

1. Introduction: Challenges in Large-Diameter Slicing

The semiconductor industry is rapidly transitioning from 8-inch to 12-inch wafers. Sapphire (α-Al₂O₃, Mohs hardness 9) and silicon carbide (SiC, Mohs hardness 9.5), as core substrates for LEDs and power devices, present three major pain points in large-diameter processing:

1.1Uncontrolled Warpage: A 12-inch wafer has 2.25 times the surface area of an 8-inch wafer. Uneven stress release during cutting easily leads to warpage exceeding specifications (>0.1 mm), directly impacting epitaxial yield.

1.2.Edge Chipping: The hardness and brittleness of SiC make it prone to micro-cracks at the edges during traditional cutting, increasing breakage rates in subsequent grinding processes.

1.3.Efficiency Bottleneck: Traditional slurry cutting operates at low wire speeds (typically <1000 m/min) and involves abrasive contamination, making it unsuitable for the efficient, clean slicing of 12-inch ingots.

The diamond wire multi-wire saw, characterized by its "fixed abrasive + high-speed reciprocating" mechanism, has become the preferred solution to overcome these bottlenecks.

2. Core Equipment Performance and Process Compatibility

Using the TJ3000 12-inch multi-wire saw as an example, its technical parameters are specifically optimized for large-diameter hard and brittle materials (Table 1), featuring the following core capabilities:

Parameter

2.1 Sapphire Substrate Slicing: Balancing Efficiency and Flatness

12-inch sapphire substrates are primarily used in Micro-LED and high-power LED applications. The TJ3000 employs a "top-down plunge cutting" method (workpiece descends, wire web remains static) combined with a ±8° oscillating mechanism to disperse cutting stress effectively. Field data shows: when cutting 1.25 mm thick sapphire, the yield exceeds 95%, warpage is controlled within 0.08 mm, and the wire breakage rate is <0.1%, significantly outperforming traditional slurry cutting.

2.2 Silicon Carbide Substrate Slicing: Overcoming High Hardness

SiC ingots are high-value, making material loss during cutting a critical cost factor. The "narrow kerf" characteristic of diamond wire cutting (wire diameter 0.12–0.25 mm) reduces material loss by approximately 30% compared to slurry cutting. To address SiC's extreme hardness, the equipment increases wire speed to over 2000 m/min and utilizes anti-rust cutting fluid (TJ series) to avoid surface contamination from embedded loose abrasives.

3. Key Technological Breakthroughs and Benefit Analysis

3.1 Adaptive Tension Technology

Tension fluctuations in the wire web are a primary cause of inconsistent slice thickness (TTV failure) in large-diameter cutting. The TJ3000's fully servo-driven tension system provides real-time compensation for wire wear, maintaining tension fluctuation within <±1 N during long continuous operations, ensuring consistency from the first to the last slice.

3.2 Cost-Benefit Comparison

Taking 12-inch SiC substrate production as an example, where cutting loss accounts for up to 50% of the cost per wafer in traditional slurry cutting, switching to diamond wire yields:

Material Saving: Kerf width is reduced from 0.18 mm to 0.12 mm, yielding 2–3 additional usable substrates per ingot.

Efficiency Gain: Wire speed increased to 2500 m/min shortens cutting time by approximately 40%.

Comprehensive Cost Reduction: The total processing cost per wafer is reduced by about 15%, with the added benefit of eliminating slurry waste disposal, offering significant environmental advantages.

4. Conclusion and Outlook

The 12-inch diamond wire multi-wire saw is a critical enabler for the cost reduction and efficiency improvement of the third-generation semiconductor industry. Its application in slicing 12-inch sapphire and silicon carbide demonstrates:

4.1.High Precision: Constant tension and oscillatory cutting resolve warpage and edge chipping issues in large-diameter wafers.

4.2.High Efficiency: A high wire speed of 2500 m/min significantly boosts throughput, meeting mass production demands.

4.3.Low Loss: The narrow kerf design dramatically improves material utilization, reducing the cost of expensive ingots.

Looking forward, with the integration of technologies like endless diamond wire loops and AI-based visual alignment systems, multi-wire saws will evolve further toward "zero wire breakage and full automation," providing a more robust equipment foundation for the widespread adoption of 12-inch semiconductor materials.