Formation of periodic grain boundary in an Si thin film crystallized by a linearly polarized Nd:YAG pulse laser with an ultra sonic oscillator

2004 ◽  
Vol 808 ◽  
Author(s):  
Hirokazu Kaki ◽  
Takehiko Ootani ◽  
Susumu Horita
Keyword(s):  
Grain Boundary ◽  
Pulse Laser ◽  
Pulse Number ◽  
Novel Technique ◽  
Thermal Distribution ◽  
Irradiation Pulse ◽  
Linearly Polarized ◽  
Boundary Location ◽  
Amorphous Si ◽  
Si Thin Film

ABSTRACTIn order to obtain a large silicon (Si) grain and to control the location of its boundary in a Si film melting-crystallized by a pulse laser, we have proposed to use periodic thermal distribution spontaneously induced by irradiation of a linearly polarized laser beam. We estimated the suitable amorphous Si (a-Si) thickness taking account of multiple reflection theoretically and confirmed it experimentally. Also, we proposed a novel technique to reduce the irradiation pulse number to control the grain boundary location stably in the crystallized Si film, in which the elastic wave was generated on the surface of a-Si film prior to melting-crystallization by using an ultra sonic oscillator. Owing to this technique, we can control the grain boundary location periodically with only 1 pulse irradiation in the crystallized Si film.

Influence of the Beam Irradiation Condition With Oblique Incidence on Crystallization of an Si film by a Linearly Polarized Pulse Laser

2002 ◽  
Vol 715 ◽  
Author(s):  
Yasunori Nakata ◽  
Hirokazu Kaki ◽  
Susumu Horita
Keyword(s):  
Grain Boundary ◽  
Film Thickness ◽  
Pulse Laser ◽  
Oblique Incidence ◽  
Incident Angle ◽  
Pulse Number ◽  
Experimental Results ◽  
Irradiation Condition ◽  
Beam Irradiation ◽  
Linearly Polarized

AbstractWe investigated influence of the beam irradiation conditions with oblique incidence on crystallization of an Si film by a linearly polarized pulse laser in order to enlarge the periodic width of grain boundary. The irradiation conditions are fluence, pulse number and film thickness. We can obtain the periodic width of about 900 nm by increasing the incident angle to 25°. The experimental results suggest that the pulse number and the film thickness should be controlled properly as well as fluence in order to produce large grain stably for the oblique incidence. The detail of these conditions was discussed.

Periodic Alignment of Silicon Dot Fabricated by Linearly Polarized Nd:YAG Pulse Laser

2006 ◽  
Vol 910 ◽  
Author(s):  
Kensuke Nishioka ◽  
Susumu Horita
Keyword(s):  
Thin Film ◽  
Energy Density ◽  
Laser Beam ◽  
Density Distribution ◽  
Pulse Laser ◽  
Incident Beam ◽  
Sio2 Film ◽  
Energy Density Distribution ◽  
Linearly Polarized ◽  
Si Thin Film

AbstractPeriodically aligned submicron Si dots were fabricated by only irradiating linearly polarized Nd:YAG pulse laser to the amorphous silicon (a-Si) thin film deposited on silicon dioxide (SiO2) film. Interference between the incident beam and the scattered surface wave leads to the spatial periodicity of beam energy density distribution on the surface of the irradiated samples. The a-Si thin film was melted by laser beam, and then, the molten thin Si film was split and condensed due to its surface tensile according to the periodic energy density distribution. The polycrystalline Si (poly-Si) fine lines were formed periodically. After the first irradiation, the sample was rotated by 90o, and the laser beam was irradiated. The periodic energy density distribution was generated on the Si fine lines. Then, the lines were split off and condensed according to the periodic energy density distribution, and the periodically aligned submicron Si dots were fabricated on the SiO2 film.

Uniform Poly-Si TFTs for AMOLEDs Using Field-Enhanced Rapid Thermal Annealing

2007 ◽  
Vol 124-126 ◽  
pp. 447-450 ◽  
Author(s):  
Hyoung June Kim
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Thin Film Transistors ◽  
Solid Phase ◽  
Radiative Heating ◽  
Solid Phase Crystallization ◽  
Glass Substrates ◽  
Grain Structures ◽  
Amorphous Si ◽  
Si Thin Film

Polycrystalline Si thin film transistors (TFTs) have been fabricated through solid phase crystallization using field-enhanced rapid thermal annealing (FE-RTA) system. The system consists of inline furnace modules for preheating and cooling of the glass substrates and a process module for rapid radiative heating combined with alternating magnetic field induction. The FE-RTA system enables crystallization of amorphous Si at high throughputs without any glass damages. While the typical grain structures of poly-Si by FE-RTA are similar to those of solid phase crystallization, the residual amorphous Si and intragranular defects are reduced.

Location Control of Laterally Columnar Si Grains by Dual-Beam Excimer-Laser Melting of Si Thin-Film

2000 ◽  
Vol 621 ◽  
Author(s):  
Ryoichi Ishihara
Keyword(s):  
Thin Film ◽  
Grain Boundary ◽  
Heat Source ◽  
Grain Boundaries ◽  
Excimer Laser ◽  
Laser Melting ◽  
Dual Beam ◽  
Single Grain ◽  
Free Area ◽  
Si Thin Film

ABSTRACTThe offset of the underlying TiW is introduced in the island of Si, SiO2 and TiW on glass. During the dual-beam excimer-irradiation to the Si and the TiW, the offset in TiW acts as an extra heat source, which melts completely the Si film near the edge, whereas the Si inside is partially melted. The laterally columnar Si grains with a length of 3.2 μm were grown from the inside of the island towards the edge. By changing the shape of the edge, the direction of the solidification of the grain was successfully controlled in such a way that the all grain-boundaries are directed towards the edge and a single grain expands. The grain-boundary-free area as large as 4 μm × 3 μm was obtained at a predetermined position of glass.

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