Epitaxial Structure Using AP-MOCVD Growth of Deep-UV Led on SIC Substrates

The main objective of this project is to develop the deep UV light-emitting diodes (wavelength ranging from 250 nm to 350 nm) on silicon carbide (SiC) substrate by using Atmospheric Pressure Metal Organic Chemical Vapor Deposition (AP-MOCVD). In the first year: To achieve the target that the thickness of AlN buffer layer is larger than 1.5 µm by using variable V/III ratio and growth temperature. Besides, to study the defect density and surface morphology properties of AlN film, such as Pits and Pin holes. Additionally, to optimize the epitaxial conditions and try the different structures to decrease the defect density below than 1e+6 and the surface roughness is below 0.5 nm. Furthermore, it is easier to achieve a higher n-type doping level by adding gallium composition into the AlN film. Therefore, to achieve a n- AlxGa1-xN(x＞=0.5) film with better quality and exhibiting a n-type doping concentration around 3-5x1018 cm-3 by optimal the condition of a transition layer with gradual composition. In the second year: We will try to develop the AlGaN/AlGaN multiple-quantum-wells and explore the impact of different compositions and thickness of quantum well and barrier on the emission efficiency and the wavelength. Furthermore, we try to study the p-type doping efficiency. It is expected to achieve the p-type AlxGa1-xN(x＞=0.5) film with p-type doping concentration around 1017cm-3. In the third year: According to the research results of 1st and 2nd year, we will try to build the fully epitaxial structure of deep UV light-emitting diodes. Furthermore, to make chips by the simple and traditional process and do the measurements. By the feedback of the measurements, we will try to adjust the structures for optimal the optoelectronic properties of LEDs. It is expected to achieve the external-quantum-efficiency over 1.5% at a driving current of 20mA, and the forward voltage is below 8 volts.

Project ID:PB10308-4315
External Project ID:MOST103-2221-E182-018