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.

Etching Properties of Hydrogenated Amorphous Silicon

1991 ◽  
Vol 219 ◽  
Author(s):  
Y. S. Tsuo ◽  
Y. Xu ◽  
D. W. Baker ◽  
S.K Deb
Keyword(s):  
Amorphous Silicon ◽  
Plasma Etching ◽  
Hydrogen Content ◽  
Chemical Etching ◽  
Isopropyl Alcohol ◽  
Hydrogen Plasma ◽  
Hydrogenated Amorphous Silicon ◽  
Wet Chemical ◽  
Wet Chemical Etching ◽  
Hydrogenated Amorphous

ABSTRACTWe have studied wet-chemical and dry etching properties of doped and undoped hydrogenated amorphous silicon (a-Si:H) films with bonded hydrogen content varying from 0 to 20 at.%. Etching processes studied include (1) wet-chemical etching using solutions of KOH, isopropyl alcohol (IPA), and H2O, (2) hydrogen plasma etching, and (3) XeF2 vapor etching.

Effects of secondary pretreatments of substrate on the nucleation of diamond film

1996 ◽  
Vol 11 (7) ◽  
pp. 1787-1794 ◽  
Author(s):  
W. S. Yang ◽  
Jung Ho Je
Keyword(s):  
Plasma Etching ◽  
Chemical Etching ◽  
Diamond Powder ◽  
Structural Defects ◽  
Nucleation Density ◽  
Diamond Nucleation ◽  
Si Substrates ◽  
Nucleation Sites ◽  
Wet Chemical ◽  
Wet Chemical Etching

The effects of secondary pretreatments on diamond nucleation were investigated for the Si substrates pretreated by the diamond abrasion. When the substrate was just abraded with diamond powder, the nucleation density of diamond was 7 × 108/cm2. However, the nucleation density was found to be greatly decreased by various secondary pretreatments except by one wet chemical etching method. The nucleation density was reduced to 3 × 107/cm2 by the chemical etching (I), to 7 × 106/cm2 by the H2 plasma etching, and to ∼104/cm2 by the Ar sputtering, or O2 plasma etching. It was very slightly reduced to 3 × 108/cm2 by the chemical etching (II). The effects of secondary pretreatments in reducing the nucleation density were found to be very closely related to the removal of diamond seeds rather than topographic sites or structural defects. Therefore, diamond seeds generated by the diamond abrasion are considered as the main nucleation sites of diamond.

Increase of Solar Cell Efficiency in Graded Band Gap Structure

2015 ◽  
Vol 1117 ◽  
pp. 114-117
Author(s):  
J. Kaupužs ◽  
Arturs Medvid'
Keyword(s):  
Solar Cell ◽  
Band Gap ◽  
High Surface ◽  
Surface Recombination ◽  
Surface Recombination Velocity ◽  
Solar Cell Efficiency ◽  
Cell Efficiency ◽  
Recombination Velocity ◽  
Graded Band Gap ◽  
Band Gap Structure

The photo current-voltage characteristic of a solar cell with graded band gap is calculated numerically based on the drift-diffusion equation and Poisson equation. The calculated efficiency of the CdTe solar cell with p-n junction located in 1μm depth increases remarkably when the band gap of the front n-type layer is graded. The effect is strong for high surface recombination velocity and is remarkable even at: the calculated efficiency increases from 19.6% to 24.3%.

Decoupling high surface recombination velocity and epitaxial growth for silicon passivation layers on crystalline silicon

2017 ◽  
Vol 50 (6) ◽  
pp. 065305 ◽  
Author(s):  
Kees Landheer ◽  
Monja Kaiser ◽  
Marcel A Verheijen ◽  
Frans D Tichelaar ◽  
Ioannis Poulios ◽  
...  
Keyword(s):  
Epitaxial Growth ◽  
Crystalline Silicon ◽  
High Surface ◽  
Surface Recombination ◽  
Surface Recombination Velocity ◽  
Passivation Layers ◽  
Recombination Velocity

Contactless Measurement of Carrier Lifetime on Silicon Ingots and Bricks

2009 ◽  
Vol 1210 ◽  
Author(s):  
James S Swirhun ◽  
M Keith Forsyth ◽  
Tanaya Mankad ◽  
Ronald Alan Sinton
Keyword(s):  
High Efficiency ◽  
High Surface ◽  
Surface Recombination ◽  
Poor Quality ◽  
Surface Recombination Velocity ◽  
Contactless Measurement ◽  
Photogenerated Carrier ◽  
Silicon Sample ◽  
Recombination Velocity ◽  
Quality Material

AbstractHigh efficiency silicon solar cells demand the use of high lifetime silicon wafers. Characterization of boules and bricks before wafering allows poor quality material to be rejected before expensive processing steps. This paper extends simulation techniques previously used in quasi-steady-state-photoconductance to transient photoconductance decay measurements of high lifetime bulk samples. Simulated photogenerated carrier density profiles allow estimation of the bulk lifetime of a thick silicon sample with high surface recombination velocity.

Surface Recombination and Vacuum/GaN/AlGaN Surface Quantum Wells

2005 ◽  
Vol 892 ◽  
Author(s):  
Xiyao Zhang ◽  
Ian Patrick Wellenius ◽  
Ailing Cai ◽  
John Muth ◽  
John Roberts ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Quantum Well ◽  
Quantum Wells ◽  
Electric Fields ◽  
Surface Recombination ◽  
Surface Preparation ◽  
Energy Shift ◽  
Surface Recombination Velocity ◽  
Metal Organic ◽  
Recombination Velocity

AbstractSurface quantum wells of gallium nitride have been grown by Metal Organic Vapor Phase Epitaxy on top of AlGaN/GaN heterostructures. One boundary of the quantum well is vacuum (or air)/GaN interface, the other is GaN/AlGaN interface, and the width of the quantum well is the thickness of gallium nitride cap, and quantum confinement is demonstrate by the energy shift in photoluminescence, and cathodoluminescence as the GaN cap thickness is varied. The efficiency of the quantum well emission is sensitive to the surface environment and resulting surface recombination velocity. In this study the surface is altered by surface preparation treatments and resulting in changes in the luminescence. The changes in the efficiency of quantum well luminescence with surface treatments are attributed to changes in surface recombination velocity and surface electric fields.

Decapsulation Techniques for Cu Wire Bonding Package

2009 ◽  
Author(s):  
Dongmei Meng ◽  
Joe Rupley ◽  
Chris McMahon
Keyword(s):  
Laser Ablation ◽  
Thin Layer ◽  
Chemical Etching ◽  
Wire Bonding ◽  
Methods And Techniques ◽  
Wet Chemical ◽  
Wet Chemical Etching ◽  
Reliability Issue ◽  
Etch Time ◽  
Device Technology

Abstract This paper presents decapsulation solutions for devices bonded with Cu wire. By removing mold compound to a thin layer using a laser ablation tool, Cu wire bonded packages are decapsulated using wet chemical etching by controlling the etch time and temperature. Further, the paper investigates the possibilities of decapsulating Cu wire bonded devices using full wet chemical etches without the facilitation of laser ablation removing much of mold compound. Additional discussion on reliability concerns when evaluating Cu wirebond devices is addressed here. The lack of understanding of the reliability of Cu wire bonded packages creates a challenge to the FA engineer as they must develop techniques to help understanding the reliability issue associated with Cu wire bonding devices. More research and analysis are ongoing to develop appropriate analysis methods and techniques to support the Cu wire bonding device technology in the lab.

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