GaN RTD Epitaxial Wafer *S
Due to the early start of research on GaAs based RTDs (resonant tunneling diodes) and the high maturity of related products, RTDs based on III group arsenide material systems have achieved commercial applications. Compared with GaAs materials, GaN materials have a wider bandgap, higher saturation electron rate, and thermal stability. Therefore, GaN based RTDs have the potential to achieve higher operating frequencies and output power at room temperature. Moreover, the AIN/GaN heterojunction interface has a large conduction band order (~2.1eV), which makes the AI (Ga) N/GaN double barrier RTD have good tunability. PAM-XIAMEN can grow GaN RTD epitaxial wafer, with the following epi-structure as an example. We also offer customized growth services. Send your structure to [email protected], we will support you professionally.
1. GaN RTD Epitaxial Structure
| Epi Layer | Material | Thickness | Doping Concentration |
| Contact Layer | n-GaN | – | Si：2*1019cm-3 |
| Spacer | UID GaN | – | |
| Tunneling Barrier | AlN | – | |
| QW | GaN | – | |
| Tunneling Barrier | AlN | 1.5nm | |
| Spacer | UID GaN | – | |
| Contact Layer | n-GaN | – | – |
| Buffer | GaN buffer | ||
| Substrate | FS GaN or GaN/Sapphire template |
RTD is a quantum effect device and also a vertical type device. Nitride based resonant tunneling diodes are considered ideal devices for achieving high-power terahertz oscillation sources at room temperature and are currently a hot topic in RTD research internationally. GaN material itself has a large longitudinal optical (LO) phonon energy (92meV), which can be studied through GaN based RTD devices to investigate the mechanism of interband transition in nitrides, laying the foundation for realizing interband transition optical devices, such as room temperature quantum cascade lasers.
2. Performance Study of GaN Resonant Tunneling Diodes on Different Substrates
A team has studied the performance differences of AlN/GaN RTDs grown on free-standing (FS) GaN substrate and GaN/Sapphire template. The research results indicate that the lattice matching and thermal matching of the substrate are crucial for the epitaxial growth quality and device performance of RTDs. Lower defect density, flat surface morphology, and abrupt heterojunction interfaces are key factors in achieving room temperature negative differential resistance (NDR) characteristics. In addition, compared to sapphire substrate, FS GaN substrate has better lattice matching and thermal matching, enabling the growth of high-quality GaN epitaxial layers and achieving NDR characteristics at room temperature.
This study also confirms the possibility of precise control of resonant tunneling by growing nitrides on sapphire substrates, providing a new, cheaper, and easier to integrate substrate choice for achieving nitride resonant tunneling structures, and will greatly promote the development of nitride based single-chip microwave integrated circuits on sapphire substrate and even silicon substrate.
In the future, further in-depth research is needed to investigate the growth mechanism of GaN based RTDs on two substrates using MBE method, and explore methods to reduce defect density and improve device performance.
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Whether you need GaN epitaxy for research or for industrial applications, please contact us email at [email protected] and [email protected].