Novel low-cost technology for UV LEDs based on HVPE grown AlGaN structures

Historically, hydride vapor phase epitaxy (HVPE) was the first technique to produce high quality thick GaN epitaxial layers. Resent progress in growing of multi-layer structure by HVPE in TDI make it possible to develop this technique to fabricate multi-layer GaN- AlxGa1-xN and AlxGa1-xN -AlyGa1-yN heterostructures for light emitting diodes (LEDs) in UV spectral range with operating wavelength up to 280 nm. Additionally, TDI is going to clarify possibility to growth AlGaN-based structure capable of 230 nm light emission. Currently, only metal organic vapor phase deposition is employed to III-V nitride devices production including light emitters and high-power microwave devices. HVPE is another epitaxial method known to deposit high quality GaN layers and AlGaN-GaN heterostructures. Recently, we demonstrated multilayer AlGaN/GaN/AlGaN p-n structures grown by this method on SiC substrates. Operated wavelength under current injection was varied from 340 to 350 nm. The results obtained give us opportunity to develop a new method of the AlGaN materials growth on sapphire substrates based on HVPE technology. Phase I objective is to prove the concept and demonstrate GaN-AlGaN structures grown on 2 inch sapphire by HVPE and suitable for UV LEDs fabrication. In the Phase II TDI will focus on the development of manufacturing technology for UV LED's.