How do you cut silicon carbide ingots into wafers?

Single-crystal SiC (Mohs 9.5) is sliced with an endless diamond wire saw: a continuous loop of high-tensile steel wire electroplated with micron diamond particles, running in one direction at 40-60 m/s. The high speed keeps contact time per diamond particle to microseconds, so feed force stays near zero and the brittle crystal is micro-ground rather than sheared.

Why does silicon carbide crack during cutting?

SiC is both extremely hard and brittle. Rigid blades and slow reciprocating wires apply concentrated mechanical pressure and frictional heat; the resulting stress propagates internal micro-cracks and edge chipping. Continuous low-force micro-grinding at high speed is what prevents that cracking.

What kerf width can diamond wire achieve on SiC?

Typical endless diamond wires for SiC run 0.18-0.25 mm in diameter, versus 0.5 mm or more for legacy blades and slurry wires. On expensive SiC boules, that difference recovers wafers that would otherwise be lost to kerf - each extra wafer per boule is significant cost savings.

Does diamond wire cutting reduce CMP time for SiC wafers?

Yes. The smooth single-direction motion leaves no saw marks and minimal sub-surface damage, so Chemical Mechanical Planarization and polishing stages take significantly less time, raising total factory throughput.

Is diamond wire used for 200 mm SiC wafers?

Yes. As the industry transitions from 150 mm to 200 mm (8-inch) SiC wafers to lower device costs, endless diamond wire sawing remains the reference slicing method because it scales with larger diameters while preserving yield and surface quality.

Revolutionizing Silicon Carbide (SiC) Wafer Production: The Precision of Diamond Wire Saws

2026-06-18

Silicon carbide (Mohs 9.5) is sliced into wafers with endless diamond wire saws because only electroplated diamond grit can cut a crystal nearly as hard as diamond itself — and only a continuous loop spinning at 40–60 m/s does it without cracking the brittle matrix. The endless wire cuts a 0.18–0.25 mm kerf, leaves chip-free edges, and minimizes the sub-surface damage that scrapes SiC wafers before CMP.

SiC hardness challenge · kerf loss · sub-surface damage · thermal stress · 200 mm wafer transition.

Silicon carbide sits at the front of the wide-bandgap semiconductor revolution: its breakdown field is roughly ten times higher than silicon’s, letting power devices run at higher voltages, frequencies and temperatures for EV traction inverters, renewable-energy grids and fast chargers. The manufacturing bottleneck is dicing — with a Mohs hardness of 9.5, just below diamond, single-crystal SiC destroys standard cutting tools and cracks under the forces of traditional slicing. This is why the industry has standardized on high-speed diamond wire saw technology for SiC wafer production.

The SiC Slicing Dilemma

SiC ingots grow slowly and expensively, so every millimeter of boule is precious. Traditional methods fail in three specific ways:

Extreme Kerf Loss

Thick abrasive wheels grind up to 40% of the ingot into non-recyclable slurry powder — catastrophic when the raw crystal costs far more than silicon.

Surface and Sub-Surface Damage

The localized pressure of rigid, slow blades forces the brittle SiC matrix to fracture, producing deep sub-surface micro-cracks and severe edge chipping that drive scrap rates up.

Thermal Shock

Friction from forcing a blade through a Mohs-9.5 material creates localized heat spikes; the resulting thermal stress propagates internal cracks and warps or shatters wafers.

The Solution: Endless Diamond Wire Saws

A closed-loop diamond wire — high-tensile steel core, electroplated with graded micron diamond particles, welded into a seamless ring — spins in one fixed direction at linear velocities frequently reaching 40–60 m/s. Three consequences follow:

1. High-Speed Micro-Grinding Instead of Shearing

Each diamond crystal touches the SiC surface for microseconds, so feeding force falls to near zero. The cut transitions from heavy mechanical shearing to gentle micro-grinding, eliminating the shock that causes micro-fractures — ultra-thin wafers come off with crisp, chip-free edges.

2. Ultra-Thin Kerf, Maximum Boule Yield

Without reversal vibration, the wire core can be made 0.18–0.25 mm thin. For expensive SiC, extracting even one or two extra wafers per boule translates directly into significant cost savings.

3. Pristine Surfaces, Faster CMP

The uninterrupted motion produces very low surface roughness (Ra) with no saw marks. Because sub-surface damage stays minimal, downstream CMP and polishing stages consume significantly less time, raising overall fab throughput.

Legacy Slicing vs Endless Diamond Wire for SiC

Parameter	ID Saw / Slurry Wire	Endless Diamond Wire
Wire / blade thickness	0.5 mm+	0.18–0.25 mm
Linear speed	Low, reciprocating	40–60 m/s, single direction
Edge quality	Chipping and cracking common	Crisp, chip-free edges
Sub-surface damage	Deep micro-cracks	Minimal
Ingot yield (kerf)	Up to 40% lost to slurry	Maximum wafers per boule

Conclusion

As the industry transitions to 200 mm (8-inch) SiC wafers to cut device costs, the machining must keep pace. The endless diamond wire saw has proven itself the definitive answer for SiC: it overcomes the extreme hardness, eliminates edge breakage and maximizes raw-material yield. To see the surface quality on your own crystal, use our free sample trial program — ship your material, and our technical team returns sliced wafers with a full parameter report (WhatsApp +86-19937798228).

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