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Full-Text Articles in Electronic Devices and Semiconductor Manufacturing

Free Standing Gan Nano Membrane By Laser Liftoff Method, Liang Tang, Yuefeng Wang, Gary Cheng, Michael Manfra, Timothy Sands Aug 2012

Free Standing Gan Nano Membrane By Laser Liftoff Method, Liang Tang, Yuefeng Wang, Gary Cheng, Michael Manfra, Timothy Sands

Yuefeng Wang

In this work, we present a method able to fabricate thin GaN nanomembranes fit for device applications. Starting from commercial GaN on sapphire substrates, MBE was used to deposit a sacrificial layer, which comprises of a superlattice of InN/InGaN, after which thin a GaN film of hundreds of nanometers thickness was grown on top. Pulsed laser irridiation with photon energy of 2.3eV gives rise to the controlled decomposition of the sacrificial intermediate layer, which can be followed by easy separation of the top GaN membrane from the substrate. This process can be used to manufacture GaN membranes with low defect …


Light Extraction Enhancement Of Gan Based Leds Using Top Gratings, Patterned Sapphire Substrates, And Reflective Surfaces, Greg Chavoor Jun 2012

Light Extraction Enhancement Of Gan Based Leds Using Top Gratings, Patterned Sapphire Substrates, And Reflective Surfaces, Greg Chavoor

Master's Theses

In the last 15 years, an immense amount of research has gone into developing high efficiency Gallium Nitride based light emitting diodes (LED). These devices have become increasingly popular in LED displays and solid state lighting. Due to the large difference in refractive index between GaN and Air, a significant amount of light reflects at the boundary and does not escape the device. This drawback decreases external quantum efficiency (EQE) by minimizing light extraction. Scientists and engineers continue to develop creative solutions to enhance light extraction. Some solutions include surface roughening, patterned sapphire substrates, and reflective layers.

This study proposes …