Product Overview of Semi-Insulating SiC Wafers

High-Purity Semi-Insulating SiC Wafers are engineered for next-generation power electronics, RF/microwave devices, and optoelectronics. Our wafers are fabricated from 4H- or 6H-SiC single crystals using an optimized Physical Vapor Transport (PVT) growth process combined with deep-level compensation annealing. The result is a wafer with:

• Ultra-High Resistivity: ≥1×10¹² Ω·cm, to suppress leakage currents in high-voltage switching devices

• Wide Bandgap (~3.2 eV): Maintains superior electrical performance under high-temperature, high-field, and high-radiation conditions

• Exceptional Thermal Conductivity: >4.9 W/cm·K, for rapid heat removal in high-power modules

• Outstanding Mechanical Strength: Mohs hardness of 9.0 (second only to diamond), low thermal expansion, and excellent chemical stability

• Atomically Smooth Surface: Ra < 0.4 nm with defect density < 1/cm², ideal for MOCVD/HVPE epitaxy and micro-nano fabrication

Available Sizes: 50, 75, 100, 150, 200 mm (2″–8″) standard; custom diameters up to 250 mm on request.
Thickness Range: 200–1 000 μm with ±5 μm tolerance.

Manufacturing Principles & Process Flow of Semi-Insulating SiC Wafers

High-Purity SiC Powder Preparation

• Starting material: 6N–grade SiC powder purified via multi-stage vacuum sublimation and thermal treatment to reduce metal contaminants (Fe, Cr, Ni < 10 ppb) and eliminate polycrystalline inclusions.

Modified PVT Single-Crystal Growth

• Environment: 10⁻³–10⁻² Torr near-vacuum

• Temperature: Graphite crucible heated to ~2 500 °C; controlled thermal gradient ΔT ≈ 10–20 °C/cm

• Gas Flow & Crucible Design: Porous graphite separators and tailored crucible geometry ensure uniform vapor distribution and inhibit unwanted nucleation

• Dynamic Feed & Rotation: Periodic SiC powder replenishment and crystal-rod rotation yield low dislocation densities (< 3 000 cm⁻²) and consistent 4H/6H orientation

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Deep-Level Compensation Annealing

• Hydrogen Anneal: 600–1 400 °C in H₂ atmosphere for several hours to activate deep-level traps and compensate intrinsic carriers

• N/Al Co-Doping (Optional): Precise incorporation of Al (acceptor) and N (donor) dopants during growth or post-growth CVD to create stable donor-acceptor pairs, driving resistivity peaks

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Precision Slicing & Multi-Stage Lapping

• Diamond-Wire Sawing: Slices wafers to 200–1 000 μm thickness with minimal damage layer; thickness tolerance ±5 μm

• Coarse to Fine Lapping: Sequential use of diamond abrasives to remove sawing damage and prepare for polishing

Chemical Mechanical Polishing (CMP)

• Polishing Media: Nano-oxide (SiO₂ or CeO₂) slurry in a mild alkaline suspension

• Process Control: Low-stress polishing parameters deliver RMS roughness of 0.2–0.4 nm and eliminate micro-scratches

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Final Cleaning & Class-100 Packaging

• Multi-Step Ultrasonic Cleaning: Organic solvent → acid/base treatments → deionized water rinse, all performed in a Class-100 cleanroom

• Drying & Sealing: Nitrogen purge drying, sealed in nitrogen-filled protective bags, and housed in anti-static, vibration-dampening outer boxes

Specification of Semi-Insulating SiC Wafers

Key Application Areas of Semi-Insulating SiC Wafers

• High-Power Electronics

  • SiC MOSFETs, Schottky diodes, high-voltage inverters, and fast-charging EV power modules leverage SiC’s low on-resistance and high breakdown field.

• RF & Microwave Systems

  • 5G/6G base-station power amplifiers, millimeter-wave radar modules, and satellite communication front-ends demand SiC’s high-frequency performance and radiation hardness.

• Optoelectronics & Photonics

  • UV-LEDs, blue-laser diodes, and wide-bandgap photodetectors benefit from an atomically smooth and defect-free substrate for uniform epitaxy.

• Extreme Environment Sensing

  • High-temperature pressure/temperature sensors, gas-turbine monitoring elements, and nuclear-grade detectors exploit SiC’s stability above 600 °C and under high radiation flux.

• Aerospace & Defense

  • Satellite power electronics, missile-borne radars, and avionic systems require SiC’s robustness in vacuum, temperature cycling, and high-G environments.

• Advanced Research & Custom Solutions

  • Quantum computing isolation substrates, micro-cavity optics, and bespoke window shapes (spherical, V-groove, polygonal) for cutting-edge R&D.

Frequently Asked Questions (FAQ) of Semi-Insulating SiC Wafers

1. Why choose semi-insulating SiC over conductive SiC?
   Semi-insulating SiC exhibits ultra-high resistivity via deep-level compensation, greatly reducing leakage currents in high-voltage and high-frequency devices, whereas conductive SiC is suited for lower-voltage or power MOSFET channel applications.

2. Can these wafers go straight into epitaxial growth?
   Yes. We offer “epi-ready” semi-insulating wafers optimized for MOCVD, HVPE, or MBE, complete with surface treatment and defect control to ensure excellent epitaxial layer quality.

3. How is wafer cleanliness guaranteed?
   A Class-100 cleanroom process, multi-step ultrasonic and chemical cleaning, plus nitrogen-sealed packaging ensure virtually zero particles, organic residue, or micro-scratches.

4. What is the typical lead time and minimum order?
   Samples (up to 5 pieces) ship within 7–10 business days. Production orders (MOQ = 5 wafers) are delivered in 4–6 weeks, depending on size and custom features.

5. Do you offer custom shapes or substrates?
   Yes. In addition to standard circular wafers, we fabricate planar windows, V-groove parts, spherical lenses, and other bespoke geometries.

About Us

ZMSH specializes in high-tech development, production, and sales of special optical glass and new crystal materials. Our products serve optical electronics, consumer electronics, and the military. We offer Sapphire optical components, mobile phone lens covers, Ceramics, LT, Silicon Carbide SIC, Quartz, and semiconductor crystal wafers. With skilled expertise and cutting-edge equipment, we excel in non-standard product processing, aiming to be a leading optoelectronic materials high-tech enterprise.