Product Description

Our sapphire wafers are made of single crystal aluminum oxide (Al₂O₃) with a hexagonal lattice structure, commonly available in C-plane, A-plane, and R-plane orientations. With broad optical transparency from near-ultraviolet (190 nm) to mid-infrared, these wafers are ideal for optical components, infrared devices, high-strength laser windows, and mask materials. Sapphire’s high hardness, thermal stability, corrosion resistance, high melting point (2045°C), and excellent transparency make it a reliable material for demanding applications, though it requires precision processing.

For LED manufacturing, sapphire wafers are essential for high-quality GaN epitaxial growth, as their surface processing directly affects the brightness and uniformity of white, blue, and green LEDs. The minimal lattice mismatch between sapphire C-plane substrates and III-V/II-VI thin films ensures excellent alignment with high-temperature epitaxy processes, making sapphire wafers indispensable for advanced optoelectronic devices.

Sapphire Wafer – Structure, Properties, and Applications

1. Structure and Composition
Our sapphire wafers are single-crystal Al₂O₃ with a hexagonal R-3c crystal structure. Each aluminum ion is surrounded by six oxygen ions, forming a stable AlO₆ octahedral network. This highly symmetrical 3D lattice ensures excellent mechanical and chemical stability.

2. Optical and Electronic Properties
Sapphire wafers feature high optical transparency across a wide range from UV to near-infrared (150–5500 nm), with a refractive index around 1.76, making them ideal for precision optical instruments and laser components. Electrically, sapphire is a highly insulating material with a wide bandgap (~9.9 eV), low dielectric loss, and excellent performance in high-voltage and high-frequency semiconductor devices, including HEMTs and GaN-based electronics.

3. Mechanical and Thermal Properties
With a Mohs hardness of 9, sapphire wafers resist scratches and abrasion. They offer high mechanical strength for precision machining, withstand high pressures, and maintain dimensional stability under extreme conditions. Thermal conductivity is around 25 W/m·K, the melting point is 2054 °C, and the thermal expansion coefficient is low (8.4 × 10⁻⁶/K), making sapphire wafers reliable for high-temperature and demanding industrial applications.

Sapphire wafer Manufacturing process:

1. Crystal Growth – Grow high-quality single crystal sapphire using advanced crystal growth furnaces.
2. Crystal Orientation – Precisely align the sapphire crystal on the sawing machine for accurate processing.
3. Rod Extraction – Slice sapphire rods from the crystal with controlled methods to maintain structural integrity.
4. Rod Grinding – Use cylindrical grinders to achieve precise outer diameters and smooth surfaces.
5. Initial Quality Check – Inspect sapphire rods for dimensional accuracy and correct crystal orientation.
6. Rod Positioning for Slicing – Align sapphire rods on slicing equipment to ensure accurate wafer cuts.
7. Slicing – Cut the sapphire rods into thin wafers with high precision.
8. Polishing – Remove cutting damage and improve wafer flatness for high-quality surfaces.
9. Chamfering – Round wafer edges to enhance mechanical strength and reduce stress-related defects.
10. Buffing – Refine surface roughness to achieve epi-ready or optical-grade precision.
11. Cleaning – Remove dust, metal residues, and organic contaminants to ensure surface purity.
12. Final Quality Inspection – Verify wafer flatness, orientation, surface quality, and cleanliness to meet strict customer specifications.

FAQ

1.Q:What are sapphire wafers used for?

   A: Sapphire wafers play a pivotal role in the optoelectronics industry. Their transparency and durability make them ideal substrates for light-emitting diodes (LEDs), laser diodes, and optical windows. The superior optical properties of sapphire contribute to the efficiency and performance of these devices.

2.Q:What is a sapphire wafer?

   A: Composed of crystalline aluminum oxide (Al2O3), sapphire wafers bring a combination of hardness, optical transparency, and chemical resilience that makes them exceptionally valuable in various applications.

3.Q:Why is sapphire so expensive?

    A:Sapphires are not as abundant as diamonds, making them harder to come by. Only a few mines around the world can produce high-quality sapphires, and even then only a small number of stones can be considered “gem-quality”. This scarcity has resulted in a significant increase in the cost of sapphires.