Optical Characterization of Buried Ingaas/GaAs Wires Overgrown by MBE

1993 ◽  
Vol 318 ◽  
Author(s):  
K. Pieger ◽  
J. Straka ◽  
Ch. Gréus ◽  
A. Forchel
Keyword(s):  
Surface Recombination ◽  
Optical Characterization ◽  
Gaas Layer ◽  
Photoluminescence Intensity ◽  
Temperature Growth ◽  
Resolution Electron ◽  
Wet Chemical ◽  
Wet Chemical Etching ◽  
Induced Defects

ABSTRACTWe have prepared buried InGaAs/GaAs wires by high resolution electron beam lithography, wet chemical etching and subsequent MBE overgrowth. Wires with lateral widths of less than 40nm have been realized.For optimized regrowth conditions such as growth temperature, growth rate, III/V ratio, and arsenic flux a smooth surface morphology of the 100nm thick overgrown (Al)GaAs layer is obtained.Etched only ultra narrow wires show a decrease of radiative recombination due to process induced defects and surface recombination at the open sidewalls. Optical investigations of narrow overgrown wires show a significant enhancement (up to two orders of magnitude) of the photoluminescence intensity. This is due to the disappearance of the open sidewalls and carrier capture from the overgrown barrier.From studies of the influence of the crystallographic orientation on the quantum efficiency we find, that <111>B surfaces of the <011> wires offer the best conditions for MBE overgrowth.

scholarly journals Surface passivation and optical characterization of Al2O3/a-SiCx stacks on c-Si substrates

2013 ◽  
Vol 4 ◽  
pp. 726-731 ◽  
Author(s):  
Gema López ◽  
Pablo R Ortega ◽  
Cristóbal Voz ◽  
Isidro Martín ◽  
Mónica Colina ◽  
...  
Keyword(s):  
Wavelength Range ◽  
Surface Passivation ◽  
Crystalline Silicon ◽  
Surface Recombination ◽  
Chemical Vapor ◽  
Optical Characterization ◽  
Surface Recombination Velocity ◽  
Carrier Injection ◽  
Si Substrates

The aim of this work is to study the surface passivation of aluminum oxide/amorphous silicon carbide (Al2O3/a-SiCx) stacks on both p-type and n-type crystalline silicon (c-Si) substrates as well as the optical characterization of these stacks. Al2O3 films of different thicknesses were deposited by thermal atomic layer deposition (ALD) at 200 °C and were complemented with a layer of a-SiCx deposited by plasma-enhanced chemical vapor deposition (PECVD) to form anti-reflection coating (ARC) stacks with a total thickness of 75 nm. A comparative study has been carried out on polished and randomly textured wafers. We have experimentally determined the optimum thickness of the stack for photovoltaic applications by minimizing the reflection losses over a wide wavelength range (300–1200 nm) without compromising the outstanding passivation properties of the Al2O3 films. The upper limit of the surface recombination velocity (S eff,max) was evaluated at a carrier injection level corresponding to 1-sun illumination, which led to values below 10 cm/s. Reflectance values below 2% were measured on textured samples over the wavelength range of 450–1000 nm.

scholarly journals Fabrication of Novel III-N and III-V Modulator Structures by ECR Plasma Etching

1995 ◽  
Vol 405 ◽  
Author(s):  
S. J. Pearton ◽  
C. R. Abernathy ◽  
J. D. MacKenzie ◽  
J. R. Mileham ◽  
R. J Shul ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Plasma Etching ◽  
Chemical Etching ◽  
High Surface ◽  
Surface Recombination ◽  
Surface Recombination Velocity ◽  
Ecr Plasma ◽  
Wet Chemical ◽  
Wet Chemical Etching ◽  
Recombination Velocity

AbstractQuantum well microdisk laser structures have been fabricated in the GaN/InGaN, GaAs/AlGaAs and GaAs/InGaP systems using a combination of ECR dry etching (Cl2/CH4/H2/Ar, BC13/Ar or CH4/H2/Ar plasma chemistries respectively) and subsequent wet chemical etching of a buffer layer underlying the quantum wells. While wet etchants such as HF/H2O and HCI/HNO3/H2O are employed for AlGaAs and InGaP, respectively, a new KOH-based solution has been developed for AlN which is completely selective over both GaN and InGaN. Typical mask materials include PR or SiNx, while the high surface recombination velocity of exposed AlGaAs (∼105cm·sec-1) requires encapsulation with ECR-CVD SiNx to stabilize the optical properties of the modulators.

Optical characterization of excess carrier lifetime and surface recombination in 4H/6H–SiC

2001 ◽  
Vol 79 (3) ◽  
pp. 365-367 ◽  
Author(s):  
A. Galeckas ◽  
J. Linnros ◽  
M. Frischholz ◽  
V. Grivickas
Keyword(s):  
Carrier Lifetime ◽  
Surface Recombination ◽  
Optical Characterization ◽  
Excess Carrier

Characterization of luminescent silicon carbide nanocrystals prepared by reactive bonding and subsequent wet chemical etching

2011 ◽  
Vol 99 (21) ◽  
pp. 213108 ◽  
Author(s):  
David Beke ◽  
Zsolt Szekrényes ◽  
István Balogh ◽  
Miklós Veres ◽  
Éva Fazakas ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Chemical Etching ◽  
Wet Chemical ◽  
Wet Chemical Etching

Structural Characterization of Silicon Carbide Etched by Using a Combination of Ion Implantation and Wet Chemical Etching

2000 ◽  
Vol 338-342 ◽  
pp. 481-484 ◽  
Author(s):  
T. Henkel ◽  
Gabriel Ferro ◽  
Shin Ichi Nishizawa ◽  
H. Pressler ◽  
Yasuhito Tanaka ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Ion Implantation ◽  
Structural Characterization ◽  
Chemical Etching ◽  
Wet Chemical ◽  
Wet Chemical Etching
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