Formation of Aluminum Oxide Films on Silicon Surface by Aluminum Evaporation in Oxygen Gas Atmosphere

2012 ◽  
Vol 1426 ◽  
pp. 421-426
Author(s):  
Y. Nagatomi ◽  
S. Yoshidomi ◽  
M. Hasumi ◽  
T. Sameshima ◽  
A. Kohno
Keyword(s):  
Aluminum Oxide ◽  
Silicon Surface ◽  
Rear Surface ◽  
Surface Recombination Velocity ◽  
Simple Method ◽  
Effective Lifetime ◽  
Gas Atmosphere ◽  
Metal Evaporation ◽  
Oxygen Gas ◽  
Thermally Grown

ABSTRACTWe report formation of thin aluminum oxide AlOx films on the silicon surface by a simple method of Al metal evaporation in oxygen gas atmosphere. 520 μm thick 30-Ωcm p-type-silicon substrates with a top bare surface and a rear surface coated with 100 nm thick thermally grown SiO2 layers were prepared. AlOx films were formed on the top surfaces by Al metal evaporation up to 20 s in oxygen gas atmosphere at 0.8 Pa with a flow rate of 3 sccm. Samples were subsequently annealed with 9.0x105 Pa H2O vapor at 260°C for 3 h. Measurement of capacitance response to a modulation voltage at 500 kHz as a function of bias gate voltages C-V revealed that AlOx films had the effective oxide thickness ranging from 2.0 and 2.6 nm were formed. C-V measurements also revealed that negative fixed charges were accumulated with a density of 5x1012 cm-2 in AlOx films. Photo-induced carrier microwave absorption measurement resulted in a high minority carrier effective lifetime τeff of 3.6x10-4 s comparable to that of 4.1x10-4 s for thermally grown SiO2 passivation. Field effect passivation was probably caused by negative charges in AlOx so that the surface recombination velocity decreased to 70 cm/s. X-ray reflectivity analysis indicated that the interfacial layer like SiOx was formed between AlOx and Si substrate. High pressure H2O vapor heat annealing caused increase in the density and decrease in the thickness of AlOx layers, although it increased the density and thickness of the interfacial SiOx layer thickness. H2O vapor treatment is effective to improve the quality of nanometer thick AlOxlayer.

scholarly journals High Performance Predictable Quantum Efficient Detector Based on Induced-Junction Photodiodes Passivated with SiO2/SiNx

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7807
Author(s):  
Ozhan Koybasi ◽  
Ørnulf Nordseth ◽  
Trinh Tran ◽  
Marco Povoli ◽  
Mauro Rajteri ◽  
...  
Keyword(s):  
Charge Density ◽  
Light Trap ◽  
Film Deposition ◽  
Fixed Charge ◽  
Surface Recombination Velocity ◽  
Limiting Factor ◽  
High Quantum Efficiency ◽  
Effective Lifetime ◽  
Fixed Charge Density ◽  
Thermally Grown

We performed a systematic study involving simulation and experimental techniques to develop induced-junction silicon photodetectors passivated with thermally grown SiO2 and plasma-enhanced chemical vapor deposited (PECVD) SiNx thin films that show a record high quantum efficiency. We investigated PECVD SiNx passivation and optimized the film deposition conditions to minimize the recombination losses at the silicon–dielectric interface as well as optical losses. Depositions with varied process parameters were carried out on test samples, followed by measurements of minority carrier lifetime, fixed charge density, and optical absorbance and reflectance. Subsequently, the surface recombination velocity, which is the limiting factor for internal quantum deficiency (IQD), was obtained for different film depositions via 2D simulations where the measured effective lifetime, fixed charge density, and substrate parameters were used as input. The quantum deficiency of induced-junction photodiodes that would be fabricated with a surface passivation of given characteristics was then estimated using improved 3D simulation models. A batch of induced-junction photodiodes was fabricated based on the passivation optimizations performed on test samples and predictions of simulations. Photodiodes passivated with PECVD SiNx film as well as with a stack of thermally grown SiO2 and PECVD SiNx films were fabricated. The photodiodes were assembled as light-trap detector with 7-reflections and their efficiency was tested with respect to a reference Predictable Quantum Efficient Detector (PQED) of known external quantum deficiency. The preliminary measurement results show that PQEDs based on our improved photodiodes passivated with stack of SiO2/SiNx have negligible quantum deficiencies with IQDs down to 1 ppm within 30 ppm measurement uncertainty.

IR and MW Absorption Techniques for Bulk and Surface Recombination Control in High-Quaiity Silicon

1995 ◽  
Vol 386 ◽  
Author(s):  
A. Kaniava ◽  
U. Menczigar ◽  
J. Vanhellemont ◽  
J. Poortmans ◽  
A. L. P. Rotondaro ◽  
...  
Keyword(s):  
Surface Recombination ◽  
Surface Recombination Velocity ◽  
Silicon Substrates ◽  
Injection Level ◽  
Effective Lifetime ◽  
Carrier Recombination ◽  
High Injection Level ◽  
High Injection ◽  
Wide Range ◽  
Recombination Velocity

ABSTRACTThe carrier recombination rate in high-quality FZ and Cz silicon substrates is studied by contactless infrared and microwave absorption techniques. Different surface treatments covering a wide range of surface recombination velocity have been used for the separation of bulk and surface recombination components and evaluating of the efficiency of passivation. Limitations of effective lifetime approach are analyzed specific for low and high injection level. Sensitivity limits of the techniques for iron contamination are discussed

Basic Characteristics of a Simultaneous Double-Side CMP Machine, Housed in a Sealed, Pressure-Resistant Container

2010 ◽  
Vol 447-448 ◽  
pp. 61-65 ◽  
Author(s):  
Kei Kitamura ◽  
Toshiro K. Doi ◽  
Syuhei Kurokawa ◽  
Yoji Umezaki ◽  
Yoji Matsukawa ◽  
...  
Keyword(s):  
High Pressure ◽  
Single Crystal ◽  
Effective Action ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Pressure Oxygen ◽  
Gas Atmosphere ◽  
High Pressure Oxygen ◽  
Oxygen Gas ◽  
Basic Characteristics

We designed and manufactured a prototype of a unique CMP machine, which can perform double-side CMP simultaneously in a sealed and pressure container as regarding effective action of the processing atmosphere around workpieces as important. Polishing experiments with single crystal silicon (Si) wafers (100) are performed by charging the container with various gases. As a result, the removal rates increased by up to 25% under high pressure oxygen gas atmosphere.

scholarly journals Влияние температуры фотонного отжига на структурные и оптические свойства пленок ZnO, синтезированных методом дуального магнетронного распыления

2019 ◽  
Vol 53 (2) ◽  
pp. 267
Author(s):  
С.В. Зайцев ◽  
В.С. Ващилин ◽  
В.В. Колесник ◽  
М.В. Лимаренко ◽  
Д.С. Прохоренков ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Crystallite Size ◽  
Annealing Temperature ◽  
Optical Transmittance ◽  
Degree Of Crystallinity ◽  
Zno Films ◽  
Gas Atmosphere ◽  
Oxygen Gas ◽  
Microstructure Density ◽  
The Degree Of Crystallinity

AbstractZinc-oxide films 1.4 μm in thickness are deposited onto glassy substrates by the dual magnetron-assisted sputtering of zinc targets in an argon and oxygen gas atmosphere. The dependences of the structural and optical characteristics of the ZnO films on the temperature of postdeposition photonic annealing are studied. It is established that an increase in the annealing temperature yields an increase in the degree of crystallinity of the films. Electron microscopy shows that the deposited ZnO coatings are columnar in structure and the microstructure density and crystallite size increase upon annealing. It is found that, at an annealing temperature of 450–650°C, the optical transmittance increases to >90% in the spectral range 400–1100 nm. The experimental results show that the temperature of vacuum photonic annealing has the most profound effect on the final properties of ZnO coatings.

The Effect of Al-BSF on Seff and Rb in Industrialized Mono-Silicon Solar Cells

2012 ◽  
Vol 472-475 ◽  
pp. 1846-1850
Author(s):  
Shan Shan Dai ◽  
Gao Jie Zhang ◽  
Xiang Dong Luo ◽  
Jing Xiao Wang ◽  
Wen Jun Chen ◽  
...  
Keyword(s):  
Solar Cells ◽  
Spectral Response ◽  
Short Circuit ◽  
Rear Surface ◽  
Surface Recombination ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Surface Recombination Velocity ◽  
Silicon Solar Cells ◽  
Back Surface

In this work, the effect of aluminum back surface field formed by screen printed various amount of Al paste on the effective rear surface recombination velocity (Seff) and the internal rear reflectance coeffeicient (Rb) of commercial mono-silicon solar cells was investigated. We demonstrated the effect of Seffand Rbon the performance of Al-BSF solar cells by simulating them with PC1D. The simulated results showed that the lower Seffcould get higher open circuit voltage (Voc), at the same time, the larger Rbcould get higher short-circuit current (Isc). Experimentally, we investigated the Seffand Rbthrough depositing Al paste with various amount (3.7, 5, 6, and 8 mg/cm2) for fabricating Al-BSF mono-silicon solar cells. Four group cells were characterized by light I-V, spectral response, hemispherical reflectance and scanning electron microscope (SEM) measurements. It was found that, a minimum Seffof 350 cm/s was gotten from the cells with Al paste of 8 mg/cm2, which was extracted by matching quantum efficiency (QE) from 800 nm to 1200 nm with PC1D, and a maximum Rbof 53.5% was obtained from Al paste of 5 mg/cm2by calculating at 1105 nm with PC1D. When the amount of Al paste was higher than 5mg/cm2, there were less Seffand lower Rb. On the other hand, when Al amount was 3.7mg/cm2, it was too little to form a closed BSF. Based on the SEM graphs and simulations with PC1D, a simple explaination was proposed for the experimental results.

An Efficient Method to Form TiO2/CdS Nanotube Arrays Using Anodic Aluminum Oxide (AAO) Templates

2017 ◽  
Vol 727 ◽  
pp. 374-380 ◽  
Author(s):  
Xiao Fei Qu ◽  
Jing Jun Yuan ◽  
Xi Da Deng ◽  
Yu Chen Hou ◽  
Yu Fei Wang ◽  
...  
Keyword(s):  
Methyl Orange ◽  
Aluminum Oxide ◽  
Anodic Aluminum Oxide ◽  
Photocatalytic Performance ◽  
Double Diffusion ◽  
Nanotube Arrays ◽  
Simple Method ◽  
Anodic Aluminum ◽  
Liquid Deposition ◽  
Degradation Of Methyl Orange

In this paper, a simple, efficient and environmental friendly method was proposed to fabricate TiO2/CdS nanotube arrays. The composite nanotubes with a core-shell coaxial structure were fabricated via a simple method of liquid deposition and double diffusion using anodic aluminum oxide (AAO) templates. The photocatalytic properties of the nanotube arrays (TiO2, TiO2/CdS) were confirmed by the degradation of methyl orange (MO) under UV irradiation. Compared to bare TiO2 nanotube arrays, TiO2/CdS composite nanotube arrays showed improved photocatalytic performance: The degradation efficiency of TiO2/CdS and TiO2 nanotube arrays towards methyl orange was 65% and 39%, respectively.

Hydrogen Passivation of Er and Si Nanocrystallites in Er-doped SiO2 - Increase in Photoluminescence-

2004 ◽  
Vol 832 ◽  
Author(s):  
N. Fukata ◽  
C. Li ◽  
H. Uematsu ◽  
T. Arai ◽  
T. Makimura ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Signal Intensity ◽  
Hydrogen Gas ◽  
Hydrogen Passivation ◽  
Si Substrate ◽  
Gas Atmosphere ◽  
Oxygen Gas ◽  
Pl Intensity ◽  
Er Doped ◽  
Si Nanocrystallites

ABSTRACTHydrogen passivation effect on the enhancement of photoluminescence (PL) of Er ions in SiO2 films contained Si nanocrystallites (nc-Si) has been investigated. Er-doped SiO2 films were fabricated by laser ablation of Er-deposited Si substrate in oxygen gas atmosphere. The PL intensity of Er ions and nc-Si were increased by hydrogen gas treatments, while ESR signal intensity of residual defects located at the interfaces between nc-Si and SiO2 was decreased. These results indicate that hydrogen passivation of residual defects is useful for the enhancement of the Er PL.

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