Laser Crystallization of Polycrystalline Silicon by Controlling Lateral Thermal Profile

1985 ◽  
pp. 21-28
Author(s):  
T. Nishimura ◽  
Y. Akasaka ◽  
H. Nakata ◽  
K. Sugahara ◽  
T. Isu
Keyword(s):  
Polycrystalline Silicon ◽  
Laser Crystallization ◽  
Thermal Profile

Silicon-Hydrogen Bonds in Boron and Phosphorous Doped Polycrystalline Silicon Thin Films

2004 ◽  
Vol 808 ◽  
Author(s):  
R. Saleh ◽  
N. H. Nickel
Keyword(s):  
Binding Energy ◽  
Polycrystalline Silicon ◽  
Binding Energies ◽  
Vibration Modes ◽  
Laser Crystallization ◽  
Hydrogen Binding ◽  
Local Vibration ◽  
Silicon Thin Films ◽  
The One ◽  
Hydrogen Effusion

ABSTRACTHydrogen bonding in laser crystallized boron and phosphorous doped polycrystalline silicon is investigated using Raman spectroscopy and hydrogen effusion measurements. During laser crystallization the intensity of the local vibration modes near 2000 and 2100 cm−1 decreases. The intensity of vibration mode at 2000 cm−1 decreases faster than the one at 2100 cm−1. From H effusion measurements, the hydrogen density-of-states (H DOS) distribution is derived. For undoped amorphous silicon the H DOS exhibits two prominent peaks at hydrogen binding energies of E– μH = –1.1 and –1.5 eV. In B doped a-Si:H the peak at –1.1 eV is less pronounced while in P doped a-Si:H the H binding energy increases by about 0.1 eV. In all samples laser crystallization causes an increase of the H binding energy by about 0.2 – 0.3 eV. However, the peaks in the H DOS observed in B-doped samples are preserved during laser crystallization.

scholarly journals Characterization of Defects and Stress in Polycrystalline Silicon Thin Films on Glass Substrates by Raman Microscopy

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Kuninori Kitahara ◽  
Toshitomo Ishii ◽  
Junki Suzuki ◽  
Takuro Bessyo ◽  
Naoki Watanabe
Keyword(s):  
Grain Boundaries ◽  
Polycrystalline Silicon ◽  
Solid Phase ◽  
Raman Microscopy ◽  
Laser Crystallization ◽  
Local Vibration ◽  
Optical Phonon Mode ◽  
Glass Substrates ◽  
Silicon Thin Films ◽  
Si Films

Raman microscopy was applied to characterize polycrystalline silicon (poly-Si) on glass substrates for application as thin-film transistors (TFTs) integrated on electronic display panels. This study examines the crystallographic defects and stress in poly-Si films grown by industrial techniques: solid phase crystallization and excimer laser crystallization (ELC). To distinguish the effects of defects and stress on the optical-phonon mode of the Si–Si bond, a semiempirical analysis was performed. The analysis was compared with defect images obtained through electron microscopy and atomic force microscopy. It was found that the Raman intensity for the ELC film is remarkably enhanced by the hillocks and ridges located around grain boundaries, which indicates that Raman spectra mainly reflect the situation around grain boundaries. A combination of the hydrogenation of films and the observation of the Si-hydrogen local-vibration mode is useful to support the analysis on the defects. Raman microscopy is also effective for detecting the plasma-induced damage suffered during device processing and characterizing the performance of Si layer in TFTs.

Improvement of Grain-Growth and Surface Roughness in Laser-Crystallized Polycrystalline Silicon Films

1997 ◽  
Vol 472 ◽  
Author(s):  
H.-S. Choi ◽  
C.-M. Park ◽  
J.-H. Jeon ◽  
B.-H. Min ◽  
M.-K. Han
Keyword(s):  
Surface Roughness ◽  
Grain Growth ◽  
Polycrystalline Silicon ◽  
Treatment Time ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Solidification Process ◽  
Laser Crystallization ◽  
Sem Images ◽  
Radical Treatment

ABSTRACTThe effects of nitrogen-radical treated amorphous silicon (a-Si) films on laser-crystallization behavior have been studied for the improvement of the grain-growth and the surface roughness. The radical treatments were performed by the rf (13.56 MHz) plasma-enhanced-chemical-vapor-deposition (PECVD) system with N2 gas before the laser-crystallization. The grain-size of the laser-crystallized polycrystalline silicon (poly-Si) film with 600 seconds of radical-treatment time was remarkably increased by the relaxation of solidification process caused by the possible evolution of solid phase SiNx compounds which shows the low thermal conductivity. The electrical conductivity at 30 °C was rather lager value of 3×10-5 Ω-1cm-1 than 1×10-5 Ω-1cm-1 of poly-Si without radical treatment, while the highly resistive SiNx compounds were formed. From the SEM images, the surface roughness was also improved by the selective etching of the 5%-water-diluted hydrofluoric (HF) acid on the grain boundaries which the SiNx compounds were well segregated into during the laser-crystallization.

Polycrystalline silicon thin-film solar cells prepared by layered laser crystallization with 540mV open circuit voltage

2014 ◽  
Vol 562 ◽  
pp. 430-434 ◽  
Author(s):  
Jonathan Plentz ◽  
Gudrun Andrä ◽  
Annett Gawlik ◽  
Ingmar Höger ◽  
Guobin Jia ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Polycrystalline Silicon ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Thin Film Solar Cells ◽  
Laser Crystallization ◽  
Silicon Thin Film

The Role of Hydrogen in Laser Crystallized Polycrystalline Silicon

2002 ◽  
Vol 744 ◽  
Author(s):  
N. H. Nickel ◽  
K. Brendel
Keyword(s):  
Polycrystalline Silicon ◽  
Hydrogen Diffusion ◽  
Laser Crystallization ◽  
Hydrogen Binding ◽  
Amorphous Precursor ◽  
Pronounced Increase ◽  
Precursor Material ◽  
Residual Hydrogen ◽  
Hydrogenated Amorphous

ABSTRACTPolycrystalline silicon produced by laser crystallization of hydrogenated amorphous silicon contains large amounts of residual hydrogen. This reservoir of hydrogen can be used to passivate additional grain boundary defects by annealing the specimens at low temperatures in vacuum. Information on hydrogen bonding is obtained from hydrogen diffusion measurements. Laser crystallization results in a pronounced increase of the hydrogen binding energy in the resulting poly-Si samples compared to the amorphous precursor material. Fully crystallized poly-Si contains H concentrations of up to 17 at.%.

Critical Technologies for Poly-Si TFT in High Resolution AM-LCD

1997 ◽  
Vol 471 ◽  
Author(s):  
I-Wei Wu
Keyword(s):  
Polycrystalline Silicon ◽  
Gate Dielectric ◽  
Solid Phase ◽  
Silicon Layer ◽  
Laser Crystallization ◽  
Switching Element ◽  
Dielectric Thickness ◽  
Aperture Ratio ◽  
Layer Deposition ◽  
Critical Issues

ABSTRACTPolycrystalline silicon (p-Si) TFT offers higher aperture ratio with integrated driver circuits compared to the conventional a-Si TFT in AM-LCD application. The advantages of the p-Si TFT as the pixel switching element will be more pronounced for AM-LCDs with large number of scan lines and/or high pixel density. This paper reviews challenges and issues associated with the technology of p-Si TFT, particularly in active silicon layer deposition, solid phase and laser crystallization, hydrogenation, leakage current, performance of different device architectures and reliability. Critical issues affecting the p-Si TFT AMLCD pixel design are analyzed, including: lithographic resolution and overlay accuracy, pixel density and aspect ratio, display format, storage to LC capacitance ratio, and gate dielectric thickness. Predictions on the regimes of dominance for different flat-panel technologies by advantages in performance and-or cost with respect to panel size and pixel density will be presented.

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