Hefei Kejing AL2O3 Sapphire Single-Crystal Substrates

Overview

Hefei Kejing AL2O₃ Sapphire Single-Crystal Substrates are high-purity, orientation-controlled monocrystalline aluminum oxide wafers engineered for demanding applications in optoelectronics, semiconductor heteroepitaxy, and high-temperature sensing. As the crystalline form of Al₂O₃—commonly known as sapphire—these substrates exhibit exceptional thermal stability, wide optical transparency from deep UV to mid-infrared (≈150 nm to 5.5 µm), and outstanding mechanical rigidity. Their hexagonal corundum structure provides an atomically ordered lattice ideal for nucleating III–V (e.g., GaN, AlN) and II–VI compound semiconductors via metalorganic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). Unlike polycrystalline or ceramic alumina, sapphire substrates eliminate grain boundary scattering and interfacial defects, ensuring reproducible film growth and device yield in LED, laser diode (LD), and power electronics fabrication.

Key Features

• Precision crystallographic orientation control: Available in standard orientations including C-plane (0001), A-plane (11–20), M-plane (10–10), and R-plane (1–102), with angular tolerance ≤ ±0.2°.
• Ultra-low surface roughness: Double-side polished substrates achieve Ra < 0.5 nm, verified by atomic force microscopy (AFM) and certified per SEMI F47 standards.
• High thermal conductivity and low thermal expansion mismatch: Enables stable operation up to 1800 °C in vacuum or inert atmospheres; compatible with rapid thermal processing (RTP) cycles.
• Chemical inertness and plasma resistance: Resists etching by halogen-based plasmas (Cl₂, BCl₃) and aggressive wet chemistries (e.g., hot phosphoric acid), supporting robust process integration.
• Controlled off-cut geometry: Customized miscut angles (e.g., 6° toward ⟨11–20⟩) available to optimize step-flow growth kinetics for GaN-based heterostructures.
• Traceable metrology: Each batch includes certificate of conformance listing X-ray diffraction (XRD) rocking curve full-width at half-maximum (FWHM), surface flatness (PV ≤ 1 µm), and particle count per ISO 14644-1 Class 5 protocols.

Sample Compatibility & Compliance

These substrates are routinely qualified for use in ISO/IEC 17025-accredited laboratories and meet material specifications referenced in ASTM F797 (Standard Test Method for Measuring Thickness of Transparent Substrates), SEMI MF1530 (Specification for Sapphire Substrates), and JEDEC JESD22-A108 (Temperature Cycling). They comply with RoHS Directive 2011/65/EU and are manufactured without intentional addition of restricted substances. For regulated environments—including GMP-compliant LED manufacturing lines—the substrates are processed in ISO Class 7 (10,000) cleanrooms, packaged in ISO Class 5 (100) laminar flow bags, and accompanied by lot-level documentation supporting FDA 21 CFR Part 11 electronic record integrity requirements.

Software & Data Management

While inherently passive components, Hefei Kejing sapphire substrates integrate seamlessly into automated wafer handling systems (e.g., cluster tools, load-lock modules) via standardized cassette formats (SEMI E1, E2). Batch traceability is supported through serialized QR-coded labels linked to a secure LIMS-compatible database containing orientation verification reports, surface inspection logs (dark-field imaging), and thermal annealing history. Optional data packages include XRD pole figure maps, ellipsometric dielectric function datasets (0.7–6.0 eV), and cross-sectional TEM-ready sample preparation guidance for interface analysis.

Applications

• Heteroepitaxial growth of GaN, AlGaN, and InGaN layers for high-brightness blue, green, and white LEDs and violet/blue LDs.
• UV photodetectors and solar-blind sensors leveraging sapphire’s intrinsic bandgap (9.9 eV) and transmission cutoff at ~200 nm.
• High-power RF devices (e.g., GaN-on-sapphire HEMTs) requiring low RF loss and high breakdown voltage.
• Infrared windows and domes for aerospace and defense systems operating up to 1000 °C in oxidizing environments.
• Reference substrates for thin-film stress calibration, nanoindentation benchmarking, and scanning probe microscopy tip characterization.
• Base platforms for microelectromechanical systems (MEMS) pressure sensors and resonators where thermal drift minimization is critical.

FAQ

What crystallographic orientations are available, and how are they verified?

Standard orientations include C-plane (0001), A-plane (11–20), M-plane (10–10), and R-plane (1–102). Each substrate undergoes high-resolution X-ray diffraction (HR-XRD) using Cu-Kα radiation; orientation accuracy is confirmed via ω-scan rocking curves with FWHM ≤ 25 arcsec for C-plane and ≤ 40 arcsec for nonpolar planes. Certificates include full θ–2θ scans and pole figure data.

Can substrates be supplied with pre-deposited buffer layers or patterned surfaces?

Yes—custom processing options include low-temperature AlN nucleation layers, SiO₂ or SiNₓ passivation, and lithographically defined alignment marks (e.g., cross-hair fiducials) compatible with stepper alignment systems. Lead times and minimum order quantities apply.

What cleaning protocols are recommended prior to epitaxy?

A standard RCA-1 (NH₄OH:H₂O₂:H₂O, 1:1:5, 75 °C, 10 min) followed by dilute HF dip (0.5% v/v, 30 sec) and N₂ dry is validated for native oxide removal. Alternative ozone-based cleans or in-situ thermal desorption under UHV (<1×10⁻⁹ Torr) are also documented in application notes.

Is dimensional customization available beyond listed stock sizes?

Yes—custom diameters (up to φ4″), thicknesses (0.2–2.0 mm), and aspect ratios are supported. Tolerance specifications follow ISO 1101 for geometric dimensioning and tolerancing (GD&T); minimum order volume applies for non-standard geometries.