Ilkay Demir
Cumhuriyet University, Turkey
Title: High quality nitride materials (AlN and AlGaN) on Si and sapphire substrates and UV-LED applications
Biography
Biography: Ilkay Demir
Abstract
The growth of thick, high quality and low-stress AlN fi lms on Si and Al2O3 substrates is highly desired for a number of applications like the development of micro and nanoelectromechanical system (MEMS and NEMS) technologies and particularly for fabricating AlGaN based UV-LEDs. UV-LEDs are attractive as they are applied in many areas, such as air and water sterilization, efficient white lighting, high-density optical data storage and military applications such as biological agent detection and non-lineof-sight communication. However, the development of UV-LEDs on Si substrates is highly desired for a series of reasons like the availability of cheap, large-diameter silicon wafers, the much lower device processing costs, and the possibility of monolithical integration of the UV-LEDs with Si circuitry. In addition, effi cient AlGaN based deep UV-LEDs require layers and substrates which are transparent in UV light. So, it is preferable to grow the AlGaN based deep UV-LEDs active layers on Si substrates as the Si can be removed by chemical treatment to allow back illumination and avoid the generation and reabsorption of UV light by backside emission. Th ese advantages make silicon an attractive substrate for AlGaN based UV devices. Additionally high quality AlN template on Al2O3 substrate still is the key layer to grow high quality AlN and high Al content AlGaN materials for DUV applications since AlN substrate price and size are not suitable for mass production.