Analytical Studies of the Capping Layer Effect on Aluminum Induced Crystallization of Amorphous Silicon

2006 ◽  
Vol 910 ◽  
Author(s):  
Husam Abu-Safe ◽  
Abul-Khair M. Sajjadul-Islam ◽  
Hameed A. Naseem ◽  
William D. Brown
Keyword(s):  
Amorphous Silicon ◽  
Layer Structure ◽  
Silicon Layer ◽  
Nodule Formation ◽  
Capping Layer ◽  
X Ray ◽  
Metal Induced Crystallization ◽  
Layer Effect ◽  
Polysilicon Films ◽  
Induced Crystallization

AbstractThe effect of capping layer on metal induced crystallization of amorphous silicon was studied. Three sets of samples were prepared in this study. All samples had the basic layer structure of amorphous silicon layer deposited on a glass substrate. This was followed by a thin aluminum layer deposition. The second and third sets, however, had a third layer of amorphous silicon with thicknesses of 20 and 50 nm, respectively. These layers were deposited on top of the aluminum. The samples were annealed at 400°C for 15, 30 and 45 minutes. The crystallization fraction in the resultant films was analyzed using X-Ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, and atomic force microscopy. It was observed that the capping layer reduces nodule formation improving the smoothness of the crystallized polysilicon films.

In-situ X-ray Diffraction study of Metal Induced Crystallization of amorphous silicon

2008 ◽  
Vol 516 (15) ◽  
pp. 4946-4952 ◽  
Author(s):  
W. Knaepen ◽  
C. Detavernier ◽  
R.L. Van Meirhaeghe ◽  
J. Jordan Sweet ◽  
C. Lavoie
Keyword(s):  
Diffraction Study ◽  
Amorphous Silicon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Induced Crystallization ◽  
Induced Crystallization

Thickness-Dependent Micro-Raman Measurement of Poly-Si Films Prepared by Metal-Induced-Crystallization using a Ni Layer

2000 ◽  
Vol 609 ◽  
Author(s):  
Shin-ichi Muramatsu ◽  
Yasushi Minagawa ◽  
Fumihito Oka ◽  
Yoshiaki Yazawa
Keyword(s):  
Amorphous Silicon ◽  
Cross Section ◽  
Polycrystalline Silicon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Induced Crystallization ◽  
Raman Measurement ◽  
Si Films ◽  
Induced Crystallization ◽  
Uniform Composition

ABSTRACTRelatively thick amorphous silicon films for solar-cell applications were prepared by metal-induced-crystallization (MIC). Then, the thickness-dependent characteristics of micro-Raman spectra from a cross section of the prepared polycrystalline silicon (poly-Si) films were analyzed. It was found that Ni-induced crystallized films have a uniform composition that is 80% polycrystalline and 20% nanocrystalline. Also, the x-ray diffraction data show that a sub-mono-layer of Ni is sufficient for MIC of 6-μm-thick amorphous silicon (a-Si) films.

Optimization of the metal/silicon ratio on nickel assisted crystallization of amorphous silicon

2005 ◽  
Vol 869 ◽  
Author(s):  
L. Pereira ◽  
M. Beckers ◽  
R.M.S. Martins ◽  
E. Fortunato ◽  
R. Martins
Keyword(s):  
Amorphous Silicon ◽  
Spectroscopic Ellipsometry ◽  
Crystallization Time ◽  
Crystalline Fraction ◽  
Nickel Metal ◽  
Metal Induced Crystallization ◽  
Structural Improvement ◽  
Short Annealing ◽  
The One ◽  
Induced Crystallization

AbstractThe aim of this work is to optimize the metal/silicon ratio on nickel metal induced crystallization of silicon. For this purpose amorphous silicon layers with 80, 125 and 220 nm thick were used on the top of which 0.5 nm of Ni was deposited and annealed during the required time to full crystallize the a-Si. The data show that the 80 nm a-Si layer reaches a crystalline fraction of 95.7% (as detected by spectroscopic ellipsometry) after annealed for only 2 hours. No significant structural improvement is detected by ellipsometry neither by XRD when annealing the films for longer times. However, on 125 nm thick samples, after annealing for 2 hours the crystalline fraction is only 59.7%, reaching a similar value to the one with 80 nm only after 5 hours, with a crystalline fraction of 92.2%. Here again no significant improvements were achieved by using longer annealing times. Finally, the 220 nm thick a-Si sample is completely crystallized only after 10 hours annealing. These data clear suggest that the crystallization of thicker a-Si layers requires thicker Ni films to be effective for short annealing times. A direct dependence of the crystallization time on the metal/silicon ratio was observed and estimated.

The effect of substrate temperature and interface oxide layer on aluminum induced crystallization of sputtered amorphous silicon

2004 ◽  
Vol 808 ◽  
Author(s):  
Maruf Hossain ◽  
Husam Abu-Safe ◽  
Marwan Barghouti ◽  
Hameed Naseem ◽  
William D. Brown
Keyword(s):  
Substrate Temperature ◽  
Amorphous Silicon ◽  
Oxide Layer ◽  
Environmental Scanning ◽  
X Ray ◽  
Layer Sequence ◽  
Si Films ◽  
Induced Crystallization ◽  
Al Oxide ◽  
Aluminum Induced Crystallization

ABSTRACTThe effect of substrate temperature and interface oxide layer on aluminum induced crystallization (AIC) of amorphous silicon (a-Si) is investigated. The effect of substrate temperature on the AIC process was studied by changing the deposition temperate of a-Si from 200 to 300°C in a Al/a-Si/glass configuration. To study the effect of interface oxide on AIC, samples with a-Si/Al/glass, a-Si/Al-oxide/Al/glass, and Al/Si-oxide/a-Si/glass configurations were prepared at a fixed substrate temperature. The samples were annealed in the temperature range from 300°C to 525°C for different periods of time. The X-ray diffraction (XRD) patterns confirmed the crystallization of the a-Si films in the various configurations. From the analysis, we report that crystallization of a-Si happen at 350°C annealing temperature in the Al/a-Si/glass configuration. However, with or without the presence of Si-oxide at the interface, crystallization saturated after annealing for 20 minutes at 400°C. On the other hand, when Al-oxide is present at the interface, higher annealing temperatures and longer annealing times are required to saturate the crystallization of a-Si. Environmental Scanning Electron Microscope (ESEM) and Energy Dispersive X-Ray (EDX) mapping were used to study the surface morphology as well as the layer sequence after crystallization. This analysis revealed that Si-Al layer-exchange happens regardless of the deposited film configuration.

Polysilicon Films Formed On Alumina By Aluminium Induced Crystallization Of Amorphous Silicon

2006 ◽  
Vol 910 ◽  
Author(s):  
Etienne Pihan ◽  
Abdelilah Slaoui ◽  
Claude Maurice
Keyword(s):  
Amorphous Silicon ◽  
Grain Orientation ◽  
Coincident Site Lattice ◽  
Grain Structure ◽  
Structural Quality ◽  
Orientation Imaging ◽  
Polysilicon Films ◽  
Si Films ◽  
Induced Crystallization

AbstractWe investigated the structural quality of polysilicon films fabricated by the aluminium induced crystallization (AIC) of amorphous silicon on alumina substrates. We analyzed the overall crystallographic quality of the poly-Si films in terms of grain size distribution and grain orientation versus crystallization temperature. For these studies, we used extensively the orientation imaging micrograph (OIM) technique, a very powerful tool that allows elucidating the inner-grain structure, the grain boundaries, the grain orientation. From our analysis, we may conclude that the polysilicon films formed by AIC on alumina substrates have the following features: (i) for all investigated temperatures, most of the silicon grains have a deviation angle from (100) crystallographic orientation between 5 and 25°; (ii) increasing the annealing temperature tends to decrease the (100) preferred orientation; (iii) the angular boundary distribution revealed that the main defects are those that have been observed inside isolated dentrites, namely low angle boundaries (<2°) and coincident site lattice boundaries such as Σ3, Σ9 and Σ27.

A Novel Back-Reflecting UV-Assisted Metal-Induced Crystallization of Silicon on Glass

2001 ◽  
Vol 664 ◽  
Author(s):  
Leila Rezaee ◽  
Shamsoddin Mohajerzadeh ◽  
Ali Khakifirooz ◽  
Saber Haji ◽  
Ebrahim Asl Soleimani
Keyword(s):  
Silicon Film ◽  
Crystallization Rate ◽  
Ultra Violet ◽  
Hole Mobility ◽  
Metal Induced Crystallization ◽  
Polysilicon Films ◽  
Novel Method ◽  
Uv Photons ◽  
Lateral Crystallization ◽  
Induced Crystallization

ABSTRACTA novel method of UV-assisted metal-induced-crystallization is introduced to grow polysilicon films on ordinary glass at temperatures as low as 400°C. Annealing is accomplished in the presence of an ultra-violet exposure, leading to high crystallinity of the silicon film as confirmed by XRD, TEM and SEM analyses. A back-reflecting chromium layer is incorporated to further trap UV photons and enhance their absorption in the silicon film. This results in a significant increase in the crystallization rate as studied by XRD spectroscopy. A growth rate of 2 µm/hr is observed at 400 °C, when employing this method for lateral crystallization. Thin-film transistors fabricated using the proposed UV-assisted MILC show a threshold voltage of 1V and hole mobility of about 50 cm2/V.s.

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