Gallium Nitride (GaN) Epitaxial Grown on Sapphire Wafers 

GaN on Sapphire Wafers for RF, LED and Power Device Research

Gallium Nitride (GaN) on sapphire wafers combine a wide-bandgap GaN epitaxial layer with a durable and cost-effective sapphire substrate. This material platform is widely used to fabricate light-emitting diodes, laser diodes, ultraviolet photodetectors, RF components, High-Electron-Mobility Transistors (HEMTs), and other high-frequency or high-power semiconductor devices.

UniversityWafer supplies GaN-on-sapphire epitaxial wafers with multiple wafer diameters, GaN layer thicknesses, doping options, crystal orientations, and polishing configurations. Available structures may include unintentionally doped GaN, silicon-doped n-type GaN, magnesium-doped p-type GaN, AlN nucleation layers, and custom epitaxial layer stacks.

Send us your required diameter, layer structure, doping, GaN thickness, sapphire thickness, orientation, polish, quantity, and characterization requirements. We can help identify an available wafer or provide a custom quotation.

Buy GaN on Sapphire Wafers Online or contact us for custom epitaxial specifications.

Why Use Gallium Nitride on Sapphire?

GaN is a direct-bandgap III–V semiconductor with a bandgap of approximately 3.4 eV. As a wide-bandgap semiconductor, GaN supports high electric fields, elevated operating temperatures, and high-frequency device operation. Sapphire provides an established foundation for GaN epitaxy, particularly for optoelectronic and RF research.

Researchers select GaN on sapphire for applications such as:

• Blue, green, violet, and ultraviolet LEDs
• Laser diodes and optical emitters
• UV photodetectors and optical sensors
• RF and microwave power amplifiers
• GaN HEMTs and transistor development
• 5G and millimeter-wave device research
• High-temperature electronic devices
• Nanophotonics and integrated photonics
• Radiation-tolerant semiconductor research

Available GaN Epitaxial Platforms

The substrate and buffer structure should be selected according to the intended device, thermal requirements, wafer diameter, and fabrication process. Commonly requested configurations include:

• GaN on Sapphire: GaN epitaxial layers grown on c-plane Al₂O₃ for LEDs, photodetectors, optical devices, RF research, and general GaN device fabrication.
• GaN/AlN on Sapphire: An AlN nucleation or buffer layer between the GaN film and sapphire substrate to support epitaxial growth and device-layer engineering.
• GaN on Silicon Carbide: GaN deposited on SiC substrates for applications requiring improved heat dissipation and high RF power density.
• GaN on Silicon: GaN epitaxial structures on silicon wafers for larger-diameter processing, device prototyping, and semiconductor fabrication research.
• AlGaN/GaN Structures: AlGaN/GaN epitaxial wafers for HEMTs, RF devices, sensors, and high-power transistor development.

GaN on Sapphire Wafer Specifications

The table below presents examples of previously available GaN-on-sapphire wafer configurations. Inventory may change, and additional diameters, doping levels, film thicknesses, and layer stacks may be available upon request.

Abbreviations: UID means unintentionally doped, DSP means double-side polished, SSP means single-side polished, and TTV means total thickness variation.

The image above shows a 50.8 mm GaN-on-sapphire wafer supplied in a single-wafer carrier. Ask about SSP or DSP surfaces, wafer carriers, measurement reports, strained heteroepitaxial growth, and epitaxial overgrowth options.

Choosing GaN Doping and Layer Thickness

The correct doping and GaN thickness depend on the intended device structure. UniversityWafer can help researchers compare the following options:

• UID GaN: Commonly requested for buffer layers, optical studies, photodetectors, transistor development, and research requiring low intentional doping.
• Si-doped GaN: Used when an n-type conductive GaN layer is required.
• Mg-doped GaN: Used to produce p-type GaN for LEDs, junction devices, and related optoelectronic structures.
• Thin GaN films: Nanometer-scale GaN layers may be requested for nanophotonics, metasurfaces, optical resonators, and thin-film device research.
• Thicker GaN layers: Micron-scale films are commonly selected for device fabrication, electrical characterization, etching, and epitaxial process development.

GaN on Sapphire for HEMT Research

High-Electron-Mobility Transistors use a heterostructure that creates a high-mobility electron channel near the interface between semiconductor layers. Researchers developing a GaN transistor or HEMT may request an AlGaN/GaN stack, an AlN nucleation layer, a UID GaN buffer, and specific cap or barrier layers.

Example HEMT-related platforms include:

• AlGaN/GaN on sapphire
• AlGaN/GaN on silicon carbide
• AlGaN/GaN on silicon <111>
• UID GaN with AlGaN transition layers
• GaN layers with AlN nucleation or buffer layers
• Custom epitaxial structures for RF and power transistors

When requesting a HEMT structure, include the desired substrate, wafer diameter, GaN buffer thickness, AlGaN composition and thickness, AlN thickness, doping, cap layer, surface roughness, bow, warp, and quantity.

GaN Wafers for RF and Microwave Devices

GaN is frequently investigated for RF power devices because its material properties support high electric fields, high-frequency switching, and high power density. Potential device applications include:

• RF power amplifiers
• Microwave and millimeter-wave circuits
• Radar and communication systems
• RF front-end modules
• Schottky barrier diodes
• 5G and wireless communication devices

For RF applications requiring improved thermal performance, researchers may compare GaN on sapphire with silicon carbide wafers. For larger-diameter process development, GaN-on-silicon structures may also be considered.

Research Example: GaN for an RF Schottky Barrier Diode

A researcher requested a GaN substrate for an RF Schottky Barrier Diode (SBD) application. One proposed configuration was:

• 100 mm GaN-on-silicon wafer
• Quantity: 10 wafers
• Application: GaN RF Schottky Barrier Diode fabrication

Contact UniversityWafer and reference #262996 when requesting related specifications or updated pricing.

GaN on Sapphire for LEDs and Photonics

GaN-on-sapphire is an established material platform for visible and ultraviolet optoelectronics. Its direct bandgap makes it suitable for light emission, while alloying GaN with indium or aluminum allows researchers to engineer optical and electronic properties for different wavelength ranges.

GaN photonic and optoelectronic applications include:

• Blue and green LEDs
• Violet and ultraviolet laser diodes
• UV photodetectors
• Optical sensors
• Micro-LED and display research
• Nanophotonic resonators
• Integrated photonic devices
• Optical and electrical characterization studies

Research Example: Thin GaN for Nanophotonics

Researchers developing GaN nanophotonic structures requested thin GaN layers on sapphire with thicknesses of approximately 100 nm and 150 nm. A related configuration included:

• 100 mm diameter wafer
• Unintentionally doped GaN
• SSP sapphire substrate
• GaN thickness: 100 nm or 150 nm
• Quantity: 15 pieces

Custom thin-film GaN wafers may be suitable for nanophotonics, optical metasurfaces, waveguides, photonic crystals, resonators, and etching studies.

GaN Material Characterization

Characterization data may be available for selected GaN-on-sapphire wafers. When requesting a quote, ask whether reports are available for:

• X-ray diffraction (XRD)
• Rocking-curve full width at half maximum (FWHM)
• Atomic force microscopy (AFM)
• Surface roughness
• Photoluminescence (PL)
• Raman spectroscopy
• Hall-effect measurements
• Carrier concentration and mobility
• Resistivity or sheet resistance
• Bow, warp, and total thickness variation
• Usable surface area and defect information

Example Mg-Doped GaN Data

Previously supplied Mg-doped GaN-on-sapphire material included the following representative values:

• FWHM of the symmetric (002) rocking curve: approximately 250 arcsec
• FWHM of the (102) rocking curve: approximately 300 arcsec
• Mg concentration: greater than 6 × 10¹⁶ cm⁻³
• Resistivity: approximately 10 Ω·cm

Related configurations included:

• 2-inch UID GaN/Al₂O₃, 4–5 µm GaN, (0001), SSP
• 2-inch Mg-doped GaN/Al₂O₃, 4–5 µm GaN, (0001), SSP

Reference #257591 when requesting related specifications and pricing.

GaN on Sapphire Compared with Silicon

GaN and silicon serve different device requirements. Conventional silicon remains widely used because of its mature fabrication infrastructure, broad diameter availability, and cost-effective processing. GaN is often selected when a device requires higher electric-field capability, higher-frequency operation, or direct-bandgap optoelectronic performance.

The best substrate depends on device voltage, frequency, thermal design, optical wavelength, fabrication compatibility, wafer diameter, budget, and required production volume.

How Is GaN Grown on Sapphire?

GaN layers are commonly deposited using Metal-Organic Chemical Vapor Deposition (MOCVD) or related vapor-phase epitaxy processes. Because GaN and sapphire have different lattice and thermal properties, a nucleation or buffer layer—often AlN or low-temperature GaN—may be introduced before the primary GaN layer is grown.

A typical simplified GaN-on-sapphire structure may include:

1. C-plane sapphire substrate
2. AlN or GaN nucleation layer
3. GaN buffer layer
4. UID, Si-doped, or Mg-doped GaN device layer
5. Optional AlGaN, InGaN, cap, quantum-well, or contact layers

Exact layer structures vary considerably between LED, HEMT, photodetector, laser, sensor, and power-device applications.

Is GaN on Sapphire Resistant to Mineral Oil?

A researcher asked whether a GaN material sheet could be exposed to mineral oil. GaN is generally chemically stable against nonpolar mineral oil under ordinary room-temperature conditions. The more significant concern is surface contamination rather than immediate chemical attack.

Oil residue can interfere with later photolithography, thin-film deposition, wire bonding, electrical contacts, or surface characterization. Researchers should establish a substrate-compatible cleaning process before exposure and confirm that the cleaner will not damage existing metals, polymers, photoresists, coatings, or device layers.

Reference #434762 when requesting related specifications or pricing.

Request a GaN on Sapphire Wafer Quote

To receive an accurate quotation, provide as much of the following information as possible:

• Wafer diameter and quantity
• Sapphire orientation and thickness
• GaN thickness
• UID, Si-doped, or Mg-doped GaN
• Target carrier concentration or resistivity
• SSP or DSP surface finish
• Required AlN, AlGaN, InGaN, or buffer layers
• Surface roughness requirements
• Bow, warp, and TTV limits
• Required XRD, AFM, PL, Raman, or Hall data
• Device application or fabrication process

Related Wafers for GaN Device Development

Researchers evaluating GaN on sapphire may also need the following materials:

• Sapphire Wafers — bare Al₂O₃ substrates for epitaxy, optical devices, and thin-film deposition.
• AlGaN/GaN Wafers — heterostructures for HEMTs, RF electronics, and sensor research.
• Silicon Carbide Wafers — high-thermal-performance substrates for RF and power-device development.
• Silicon Wafers — substrates for GaN-on-Si growth, process development, controls, and semiconductor fabrication.
• Gallium Arsenide Wafers — compound-semiconductor substrates for RF, photonic, and optoelectronic research.
• Thermal Oxide Wafers — SiO₂-coated silicon substrates for insulation, controls, and fabrication experiments.