Raman Studies of Microstructural Changes in Amorphous Silicon-Boron Alloys Due to Annealing

1989 ◽  
Vol 164 ◽  
Author(s):  
G. Yang ◽  
P. Bai ◽  
Y.-J Wu ◽  
B. Y. Tong ◽  
S. K. Wong ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Boron Content ◽  
Annealing Temperature ◽  
Volume Fraction ◽  
Crystalline Silicon ◽  
Chemical Vapor ◽  
Alloy Films ◽  
Si Substrates ◽  
Pressure Chemical ◽  
Crystalline Component

AbstractCrystallization of amorphous Sil−x.Bx alloy films by annealing is studied. Amorphous Sil−xBx. alloy films with composition of boron x ranging from 0.01 to 0.5 are deposited on Si substrates at a temperature of 480° in a low pressure chemical vapor deposition (LPCVD) system. Three films with the boron contents, 1%, 7% and 45%, are used in this study. The films are annealed in a nitrogen ambient for 30 minutes at temperatures between 600°C and 900°C. Raman spectra of the silicon vibrational mode serve as a indicator for the microstructure of the Sil−xBx, alloy films. Quantitative estimates of the volume fraction of the crystalline silicon component in respect to the amorphous silicon component in the films are calculated based on the silicon TO mode. The results show that while for the film with the boron content of 1% crystallization occurs at the annealing temperature of 500°C, the annealing temperature of 7000C is required to observe crystallization in the films with the boron contents of 7% and 45%. As the annealing temperature increases, the volume fraction of the crystalline component increases. For a given annealing temperature, the rate of crystallization depends inversely on the boron content in the films.

Variation de la contrainte des verres de silice sous cycle thermique

1992 ◽  
Vol 70 (10-11) ◽  
pp. 830-833
Author(s):  
H. Bouchard ◽  
A. Azelmad ◽  
J. F. Currie ◽  
M. Meunier
Keyword(s):  
Initial Stress ◽  
Vapor Deposition ◽  
Boron Content ◽  
Annealing Temperature ◽  
Chemical Vapor ◽  
Boron Doping ◽  
Pressure Chemical ◽  
Phosphosilicate Glass ◽  
Borophosphosilicate Glass

Using an in situ technique, stress was measured as a function of annealing temperature to investigate the effect of phosphorous and boron doping of silicon dioxide glass films deposited by low-pressure chemical vapor deposition (LPCVD). It was found that the initial stress of phosphosilicate glass is independent of the amount of phosphorus present, while the boron content influences the initial stress in borophosphosilicate glass. The stress increases to a maximum, σm, corresponding to a temperature Tm, above which the onset of viscous flow reduces the stress to zero at a temperature T0. All these parameters are dependant on dopant concentrations. The observed mechanical behavior is discussed in terms of film viscosity.

Thermal Oxidation of Amorphous Silicon-Boron Alloy

1987 ◽  
Vol 105 ◽  
Author(s):  
W. M. Lau ◽  
R. Yang ◽  
B. Y. Tong ◽  
S. K. Wong
Keyword(s):  
Chemical Vapor Deposition ◽  
Amorphous Silicon ◽  
Thermal Oxidation ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Silicon Oxide ◽  
Crystalline Silicon ◽  
Chemical Vapor ◽  
X Ray ◽  
Pressure Chemical

AbstractThe thermal oxidation of amorphous silicon-boron alloy (prepared by low pressure chemical vapor deposition) with boron contents ranged from 0–40% at a temperature range of 25- 700 °C has been carried out. Crystalline silicon and polycrystalline boron have also been studied for comparison purposes. The resultant thin oxide overlayers were characterized by X-ray photoelectron spectroscopy. It was found that both the oxidation of Si and of B are enhanced by mixing of the two elements. The oxidation of boron is significantly slower than silicon. During oxidation of silicon-boron alloy, preferential oxidation of silicon occurs at the oxide/bulk interface and the silicon oxide overlayer advances into the bulk faster than the boron oxide.

Amorphous Silicon Selenium Alloy Film Deposited Under Hydrogen Dilution

1991 ◽  
Vol 219 ◽  
Author(s):  
Muzhi He ◽  
Guang H. Lin ◽  
J. O'M. Bockris
Keyword(s):  
Amorphous Silicon ◽  
Chemical Vapor ◽  
Selenium Concentration ◽  
Alloy Film ◽  
Dark Conductivity ◽  
Flow Rate Ratio ◽  
Selenium Atom ◽  
Alloy Films ◽  
Hydrogen Dilution ◽  
Photo Response

ABSTRACTAmorphous silicon selenium alloy films were prepared by plasma enhanced chemical vapor deposition with hydrogen dilution. The flow rate ratio of hydrogen to silane was about 8:1. Amorphous silicon selenium alloy was found to have an optical bandgap ranging from 1.7 eV to 2.0 eV depending on the selenium concentration in the films. The light to dark conductivity ratios of the alloy films are ∼ 104. The optical and electrical properties, Urbach tail energy and sub-bandgap photo response spectroscopy of the alloy film were investigated. The film quality of the alloy deposited with hydrogen dilution is greatly improved comparing to that of the alloy film deposited without hydrogen dilution. The electron spin resonance experiment shows that selenium atom is a good dangling bond terminator.

Heteroepitaxial Growth of 3C-SiC on Si (111) Substrate Using AlN as a Buffer Layer

2008 ◽  
Vol 600-603 ◽  
pp. 251-254 ◽  
Author(s):  
Yong Mei Zhao ◽  
Guo Sheng Sun ◽  
Xing Fang Liu ◽  
Jia Ye Li ◽  
Wan Shun Zhao ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Chemical Vapor ◽  
Heteroepitaxial Growth ◽  
Si Substrate ◽  
Si Substrates ◽  
Good Crystallinity ◽  
Aln Film ◽  
Pressure Chemical ◽  
Aln Buffer ◽  
Sic Film

Using AlN as a buffer layer, 3C-SiC film has been grown on Si substrate by low pressure chemical vapor deposition (LPCVD). Firstly growth of AlN thin films on Si substrates under varied V/III ratios at 1100oC was investigated and the (002) preferred orientational growth with good crystallinity was obtained at the V/III ratio of 10000. Annealing at 1300oC indicated the surface morphology and crystallinity stability of AlN film. Secondly the 3C-SiC film was grown on Si substrate with AlN buffer layer. Compared to that without AlN buffer layer, the crystal quality of the 3C-SiC film was improved on the AlN/Si substrate, characterized by X-ray diffraction (XRD) and Raman measurements.

scholarly journals Conformal coating of amorphous silicon and germanium by high pressure chemical vapor deposition for photovoltaic fabrics

APL Materials ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 046105 ◽  
Author(s):  
Xiaoyu Ji ◽  
Hiu Yan Cheng ◽  
Alex J. Grede ◽  
Alex Molina ◽  
Disha Talreja ◽  
...  
Keyword(s):  
High Pressure ◽  
Chemical Vapor Deposition ◽  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Conformal Coating ◽  
Pressure Chemical ◽  
Silicon And Germanium

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.

Investigation of the off-current in amorphous silicon thin film transistors for SiO2 and SiNx. gate insulators

1996 ◽  
Vol 424 ◽  
Author(s):  
Jeong Hyun Kim ◽  
Woong Sik Choi ◽  
Chan Hee Hong ◽  
Hoe Sup Soh
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Thin Film Transistors ◽  
Chemical Vapor ◽  
Interface State ◽  
State Density ◽  
Gate Insulator ◽  
Defect States ◽  
Silicon Thin Film ◽  
Pressure Chemical

AbstractThe off current behavior of hydrogenated amorphous silicon (a-Si:H) thin film transistors (TFTs) with an atmospheric pressure chemical vapor deposition (APCVD) silicon dioxide (SiO2) gate insulator were investigated at negative gate voltages. The a-Si:H TFT with SiO2 gate insulator has small off currents and large activation energy (Ea) of the off current compared to the a-Si:H TFT with SiNx gate insulator. The holes induced in the channel by negative gate voltage seem to be trapped in the defect states near the a-Si:H/SiO2 interface. The interface state density in the lower half of the band gap of a-Si:H/SiO2 appears to be much higher than that for a-Si:H/SiNx.

THE DEPOSITION AND CONTROL OF SELF ASSEMBLED SILICON NANO ISLANDS ON CRYSTALLINE SILICON

2008 ◽  
Vol 18 (04) ◽  
pp. 901-910
Author(s):  
RAGNAR KIEBACH ◽  
ZHENRUI YU ◽  
MARIANO ACEVES-MIJARES ◽  
DONGCAI BIAN ◽  
JINHUI DU
Keyword(s):  
Electron Microscopy ◽  
Integrated Circuit ◽  
Crystalline Silicon ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
High Density ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
And Control ◽  
Circuit Technology

The formation of nano sized Si structures during the annealing of silicon rich oxide (SRO) films was investigated. These films were synthesized by low pressure chemical vapor deposition (LPCVD) and used as precursors, a post-deposition thermal annealing leads to the formation of Si nano crystals in the SiO 2 matrix and Si nano islands ( Si nI ) at c-Si /SRO interface. The influences of the excess Si concentration, the incorporation of N in the SRO precursors, and the presence of a Si concentration gradient on the Si nI formation were studied. Additionally the influence of pre-deposition substrate surface treatments on the island formation was investigated. Therefore, the substrate surface was mechanical scratched, producing high density of net-like scratches on the surface. Scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) were used to characterize the synthesized nano islands. Results show that above mentioned parameters have significant influences on the Si nIs . High density nanosized Si islands can epitaxially grow from the c-Si substrate. The reported method is very simple and completely compatible with Si integrated circuit technology.

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