GaN HEMT Epitaxial Wafer
Gallium Nitride (GaN) HEMTs (High Electron Mobility Transistors) are the next generation of RF power transistor technology. Thanks to GaN technology, PAM-XIAMEN now offer AlGaN/GaN HEMT Epi Wafer on sapphire or Silicon, and AlGaN/GaN on sapphire template.
GaN HEMT epitaxial wafer is a multilayer film grown epitaxially on a substrate, which usually includes a nucleation layer, a transition layer, a buffer layer, a channel layer, a barrier layer, a cap layer, and a passivation layer from bottom to top. The nucleation layer, like AlGaN or AlN, is used to prevent the substrate material from diffusing into the GaN epitaxial layer. The transition layer may contain hierarchical AlGaN, AlN/GaN superlattice or multilayer AlN to balance the stress between the GaN and the substrate. The higher the Al content in the barrier layer of AlGaN, the higher the 2DEG concentration at the heterojunction. Meanwhile, the lower the threshold voltage of the device, and the higher the current capacity. As the Al ratio increasing, the degree of heterogeneous crystal lattice mismatch will be higher, resulting in a decrease in gallium nitride HEMT electron mobility and a decrease in current capacity.
The High Electron Mobility Transistor (HEMT) is developed based on GaN with unique heterostructure and two-dimensional electron gas. The GaN HEMT advantages include high breakdown strength, low on-resistance and faster The switching speed, which is very suitable for medium and low voltage and medium and small power systems, such as travel adapters, wireless chargers, AC-DC converters, smart home appliances, etc. The epitaxial wafer with HEMT structure is more attractive currently for high-frequency converters, in which GaN HEMT breakdown voltage is 600~650 V. With the rapid development of gallium nitride HEMT epi technology, the price of GaN HEMT devices will be competitive, which can gain large GaN HEMT market for GaN HEMT manufacturers. Moreover, due to the gallium nitride HEMT reliability, it can be widely used in industrial fields, such as photovoltaic inverters, energy storage systems, and electric vehicles.
1. GaN HEMT Material: Available size:2”,4”,6”,8”:
More specific parameters of gallium nitride HEMT wafer for D-mode GaN HEMTs, E-mode GaN HEMTs, GaN HEMT power amplifier and RF, please refer to:
2. Now we show you an example as follows:
2.1 2″ (50.8mm)GaN HEMT Epitaxial Wafers
We offer 2″(50.8mm) gallium nitride HEMT Wafers, the GaN HEMT structure is as follows:
Structure(from top to bottom):
*undoped GaN cap(2~3nm)
* We can use Si3N to replace GaN on the top, the adhesion is strong, it is coated by sputter or PECVD.
2.2 AlGaN/GaN HEMT Epi Wafer on sapphire/GaN
|Layer #||Composition||Thickness||X||Dopant||Carrier Concentration|
2.3 2″(50.8mm),4″ (100mm)AlGaN/GaN HEMT Epi Wafer on Si
2.3.1 Specifications for Aluminium Gallium Nitride (AlGaN) / Gallium Nitride (GaN) High Electron Mobility Transistor (HEMT) on Silicon substrate.
|AlGaN/GaN HEMT Epi Wafer on Si|
|AlGaN/GaN HEMT structure||Refer 1.2|
|Growth method||Float Zone|
|Conduction Type||P or N|
2.3.2 Epi structure: Crack-free Epilayers
|Layer #||Composition||Thickness||X||Dopant||Carrier Concentration|
2.3.3 Electrical Properties of the AlGaN/GaN HEMT structure
2DEG Mobility (at 300 K) :≥1,800 cm2/V.s
2DEG Sheet Carrier Density (at 300 K) :≥0.9×1013 cm-2
RMS Roughness (AFM) : ≤ 0.5 nm (5.0 µm × 5.0 µm scan Area)
2.4 2″(50.8mm)AlGaN/GaN on sapphire
For specification of AlGaN/GaN on sapphire template, please contact our sales department: [email protected]
GaN HEMT Applications: Used in blue laser diodes, ultraviolet LEDs (down to 250 nm), and AlGaN/GaN HEMTs device.
3. Explanation of AlGaN/Al/GaN HEMTs:
Nitride HEMTs are being intensively developed for high-power electronics in high-frequency amplification and power switching applications. Often high performance in DC operation is lost when the HEMT is switched – for example, the on-current collapses when the gate signal is pulsed. It is thought that such effects are related to charge trapping that masks the effect of the gate on current flow. Field-plates on the source and gate electrodes have been used to manipulate the electric field in the device, mitigating such current-collapse phenomena.
4. GaN EpitaxialTechnology — Customized GaN epitaxy on SiC,Si and Sapphire substrate for HEMTs, LEDs:
5. GaN Device:
6. Test Characterization Equipment:
Contactless Sheet Resistance
Laser Thin Film Thickness Mapping
High Temp/High Humidity Reverse Bias
DIC Nomarski Microscope
Atomic Force Microscope (AFM)
Surface Defectivity Scan
High Temp Reverse Bias
4PP Sheet Resistance
Contactless Hall Mobility
X-ray Diffraction (XRD)/Reflectance (XRR)
7. Foundry Fabrication:
we also offer foundry GaN HEMT fabrication in the following process as follows:
Dry/Wet Metal/Dielectric Etch
Thin Film PECVD/LPCVD/Sputtering
Photolithography (0.35um min. CD)
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SiC Wafer Substrate
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