Crystal quality improvement of semipolar (20-21) GaN on patterned sapphire substrates by in-situ deposited SiN mask

2014 ◽  
Author(s):  
Tobias Meisch ◽  
Maryam Alimoradi-Jazi ◽  
Benjamin Neuschl ◽  
Martin Klein ◽  
Ingo Tischer ◽  
...  
Keyword(s):  
Quality Improvement ◽  
Crystal Quality ◽  
Sapphire Substrates ◽  
Patterned Sapphire Substrates

scholarly journals Suppressing the Initial Growth of Sidewall GaN by Modifying Micron-Sized Patterned Sapphire Substrate with H3PO4-Based Etchant

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 622 ◽  
Author(s):  
Wen-Yang Hsu ◽  
Yuan-Chi Lian ◽  
Pei-Yu Wu ◽  
Wei-Min Yong ◽  
Jinn-Kong Sheu ◽  
...  
Keyword(s):  
Sapphire Substrate ◽  
Light Emitting Diodes ◽  
Ex Situ ◽  
Initial Growth ◽  
Patterned Sapphire Substrate ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Patterned Sapphire Substrates

Micron-sized patterned sapphire substrates (PSS) are used to improve the performance of GaN-based light-emitting diodes (LEDs). However, the growth of GaN is initiated not only from the bottom c-plane but also from the sidewall of the micron-sized patterns. Therefore, the coalescence of these GaN crystals creates irregular voids. In this study, two kinds of nucleation layers (NL)—ex-situ AlN NL and in-situ GaN NL—were used, and the growth of sidewall GaN was successfully suppressed in both systems by modifying the micron-sized PSS surface.

scholarly journals Comparative Research of GaN Growth Mechanisms on Patterned Sapphire Substrates with Sputtered AlON Nucleation Layers

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3933
Author(s):  
Yuan Gao ◽  
Shengrui Xu ◽  
Ruoshi Peng ◽  
Hongchang Tao ◽  
Jincheng Zhang ◽  
...  
Keyword(s):  
Growth Mechanism ◽  
Comparative Research ◽  
Crystal Quality ◽  
Growth Mechanisms ◽  
Migration Ability ◽  
Sapphire Substrates ◽  
Gan Crystal ◽  
Patterned Sapphire Substrates

The utilization of sputtered AlN nucleation layers (NLs) and patterned sapphire substrates (PSSs) could greatly improve GaN crystal quality. However, the growth mechanism of GaN on PSSs with sputtered AlN NLs has not been thoroughly understood. In this paper, we deposited AlON by sputtering AlN with O2, and we found that the variation of thickness of sputtered AlON NLs greatly influenced GaN growth on PSSs. (1) For 10 nm thin AlON sputtering, no AlON was detected on the cone sidewalls. Still, GaN nucleated preferably in non-(0001) orientation on these sidewalls. (2) If the thickness of the sputtered AlON NL was 25 nm, AlON formed on the cone sidewalls and flat regions, and some small GaN crystals formed near the bottom of the cones. (3) If the sputtered AlON was 40 nm, the migration ability of Ga atoms would be enhanced, and GaN nucleated at the top of the cones, which have more chances to grow and generate more dislocations. Finally, the GaN growth mechanisms on PSSs with sputtered AlON NLs of different thicknesses were proposed.

Crystal quality improvement of solid-phase crystallized evaporated silicon films by in-situ densification anneal

2009 ◽  
Vol 93 (6-7) ◽  
pp. 1116-1119 ◽  
Author(s):  
Song He ◽  
Bram Hoex ◽  
Daniel Inns ◽  
Ian C. Brazil ◽  
Per I. Widenborg ◽  
...  
Keyword(s):  
Quality Improvement ◽  
Solid Phase ◽  
Silicon Films ◽  
Crystal Quality

In-situ deposited SiNx nanomask for crystal quality improvement in AlGaN

2011 ◽  
Vol 8 (7-8) ◽  
pp. 2063-2065 ◽  
Author(s):  
Kamran Forghani ◽  
Mohammadreza Gharavipour ◽  
Martin Klein ◽  
Ferdinand Scholz ◽  
Oliver Klein ◽  
...  
Keyword(s):  
Quality Improvement ◽  
Crystal Quality

Hetero-Epitaxy of Group Va Metals on Sapphire

1972 ◽  
Vol 30 ◽  
pp. 492-493
Author(s):  
J. E. O'Neal ◽  
J. J. Bellina ◽  
B. B. Rath
Keyword(s):  
Thermal Contact ◽  
High Vacuum ◽  
Electron Beam Evaporation ◽  
Ultra High Vacuum ◽  
Backing Plate ◽  
Sapphire Substrates ◽  
Deposition Parameters ◽  
Polishing Damage ◽  
Reflection Electron Diffraction

Thin films of the bcc metals vanadium, niobium and tantalum were epitaxially grown on (0001) and sapphire substrates. Prior to deposition, the mechanical polishing damage on the substrates was removed by an in-situ etch. The metal films were deposited by electron-beam evaporation in ultra-high vacuum. The substrates were heated by thermal contact with an electron-bombarded backing plate. The deposition parameters are summarized in Table 1.The films were replicated and examined by electron microscopy and their crystallographic orientation and texture were determined by reflection electron diffraction. Verneuil-grown and Czochralskigrown sapphire substrates of both orientations were employed for each evaporation. The orientation of the metal deposit was not affected by either increasing the density of sub-grain boundaries by about a factor of ten or decreasing the deposition rate by a factor of two. The results on growth epitaxy are summarized in Tables 2 and 3.

The growth behaviors and high controllability of GaN nanostructures on stripe-patterned sapphire substrates

2021 ◽  
pp. 149725
Author(s):  
Pengkun Li ◽  
Lilin Wang ◽  
Shujing Sun ◽  
Chaoyang Tu ◽  
Chenlong Chen
Keyword(s):  
Sapphire Substrates ◽  
Patterned Sapphire Substrates
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