scholarly journals Investigations of Sidewall Passivation Technology on the Optical Performance for Smaller Size GaN-Based Micro-LEDs

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 403
Author(s):  
Junchi Yu ◽  
Tao Tao ◽  
Bin Liu ◽  
Feifan Xu ◽  
Yao Zheng ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Light Emission ◽  
Internal Quantum Efficiency ◽  
Layer Growth ◽  
Device Performance ◽  
Recombination Lifetime ◽  
Inductively Coupled ◽  
Luminescence Efficiency ◽  
Passivation Process ◽  
Chip Size

Micro-light emitting diodes (Micro-LEDs) based on III-nitride semiconductors have become a research hotspot in the field of high-resolution display due to its unique advantages. However, the edge effect caused by inductively coupled plasma (ICP) dry etching in Micro-LEDs become significant with respect to the decreased chip size, resulting in a great reduction in device performance. In this article, sector-shaped GaN-based blue Micro-LEDs are designed and fabricated. Additionally, the device performance of different size Micro-LEDs with passivation are investigated with respect to those without passivation. Several methods have been applied to minimize the etching damage near the edge, including acid-base wet etching and SiO2 passivation layer growth. The room temperature photoluminescence (PL) results demonstrate that the light emission intensity of Micro-LEDs can be significantly enhanced by optimized passivation process. PL mapping images show that the overall luminescence of properly passivated Micro-LEDs is enhanced, the uniformity is improved, and the effective luminescence area is increased. The recombination lifetime of carriers in Micro-LEDs are increased by the usage of passivation process, which proves the reduction in non-radiative recombination centers in Micro-LEDs and improved luminescence efficiency. As a result, the internal quantum efficiency (IQE) is improved from 14.9% to 37.6% for 10 μm Micro-LEDs, and from 18.3% to 26.9% for 5 μm Micro-LEDs.

Inductively Coupled High-Density Plasma-Induced Etch Damage of GaN MESFETs

2000 ◽  
Vol 622 ◽  
Author(s):  
R. J. Shul ◽  
L. Zhang ◽  
A. G. Baca ◽  
C. G. Willison ◽  
J. Han ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Ion Bombardment ◽  
Critical Dimension ◽  
High Plasma ◽  
Substrate Material ◽  
Device Performance ◽  
Inductively Coupled ◽  
Profile Control ◽  
Etch Rates ◽  
Anisotropic Etch

ABSTRACTThe fabrication of a wide variety of GaN-based photonic and electronic devices depends on dry etching, which typically requires ion-assisted removal of the substrate material. Under conditions of both high plasma flux and energetic ion bombardment, GaN etch rates greater than 0.5 νm/min and anisotropic etch profiles are readily achieved in Inductively Coupled Plasma (ICP) etch systems. Unfortunately, under these conditions plasma-induced damage often occurs. Attempts to minimize such damage by reducing the ion energy or increasing the chemical activity in the plasma often result in a loss of etch rate or profile control which can limit dimensional control and reduce the utility of the process for device applications requiring anisotropic etch profiles. It is therefore necessary to develop plasma etch processes which couple anisotropy for critical dimension and sidewall profile control and high etch rates with low-damage for optimum device performance. In this study we report changes in source resistance, reverse breakdown voltage, transconductance, and drain saturation current for GaN MESFET structures exposed to an Ar ICP plasma. In general, device performance was sensitive to ion bombardment energy and ion flux.

Plasmon-Enhanced Emission Rates from III-Nitride Quantum Wells Using Tunable Surface Plasmons

2011 ◽  
Vol 1294 ◽  
Author(s):  
J. Henson ◽  
J. DiMaria ◽  
E. Dimakis ◽  
R. Li ◽  
S. Minissale ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Light Emission ◽  
Internal Quantum Efficiency ◽  
Strong Dependence ◽  
Substantial Reduction ◽  
Green Light ◽  
Photoluminescence Intensity ◽  
Emission Rates ◽  
Recombination Lifetime ◽  
Green Light Emission

ABSTRACTTwo-dimensional arrays of silver nanocylinders fabricated by electron-beam lithography are used to demonstrate plasmon-enhanced near-green light emission from nitride semiconductor quantum wells. Large enhancements in peak photoluminescence intensity (up to a factor of over 3) are obtained, accompanied by a substantial reduction in recombination lifetime indicative of increased internal quantum efficiency. The measured enhancement factors exhibit a strong dependence on the nanoparticle dimensions, underscoring the importance of geometrical tuning for this application.

Sign in / Sign up

Export Citation Format

Share Document