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Physics Seminar

Nano-engineering of III-nitride materials via wafer-scale nanopatterning

Speaker: Dr Philip Shields (University of Bath)
Date: Wednesday 15 January 2020
Time: 15:00
Venue: WX/3.07

Nano-engineering III-nitride semiconductors offers a route to further control their optoelectronic properties, enabling novel functionalities and applications. Although a variety of lithography techniques are currently employed to nano-engineer these materials, the scalability and cost of the fabrication process can be an obstacle for large-scale manufacturing.

In this talk I will introduce a fast, robust and flexible emerging patterning technique called Displacement Talbot lithography (DTL), to successfully nano-engineer III-nitride materials. DTL, along with our recent extension of D2TL, allow the fabrication of a variety of periodic nanopatterns with a broad range of filling factors such as nanoholes, nanodots, nanorings and nanolines; all these features being achievable from one single mask.

To illustrate the possibilities opened by DTL/D2TL, dielectric and metal masks with a number of nanopatterns have been generated, allowing for the selective area growth of InGaN/GaN core-shell nanorods, the top-down plasma etching of III-nitride nanostructures, the top-down sublimation of GaN nanostructures, the hybrid top-down/bottom-up growth of AlN nanorods and GaN nanotubes, and the fabrication of nanopatterned sapphire substrates for AlN growth. Compared with their planar counterparts, these 3D nanostructures enable the reduction or filtering of structural defects and/or the enhancement of the light extraction, therefore improving the efficiency of the final device.