On the super lateral growth phenomenon observed in excimer laser‐induced crystallization of thin Si films

1994 ◽  
Vol 64 (17) ◽  
pp. 2303-2305 ◽  
Author(s):  
James S. Im ◽  
H. J. Kim
Keyword(s):  
Excimer Laser ◽  
Lateral Growth ◽  
Growth Phenomenon ◽  
Si Films ◽  
Induced Crystallization

Multiple Pulse Irradiation Effects in Excimer Laser-Induced Crystallization of Amorphous Si Films

1993 ◽  
Vol 321 ◽  
Author(s):  
H. J. Kim ◽  
James S. Im
Keyword(s):  
Excimer Laser ◽  
Single Pulse ◽  
Pulse Irradiation ◽  
Multiple Pulse ◽  
Melting Phenomenon ◽  
Irradiation Energy ◽  
Crystallization Experiments ◽  
Amorphous Si ◽  
Si Films ◽  
Induced Crystallization

ABSTRACTWe have experimentally Investigated the effects that are associated with Multiple-pulse irradiation in the excimer laser processing of thin Si films on SiO2. Double-pulse irradiation experiments revealed results, which are consistent with that which is known from single-pulse crystallization experiments, and these experiments confirm the applicability of the transformation scenarios, which were derived from single pulse-induced crystallization experiments [1,2]. The results from the Multiple-pulse irradiation experiments clearly show that gradual and substantial grain enlargement can occur — and only occurs — when the irradiation energy density is close to but less than the level that is required to melt the film completely. Based on these findings, we argue that the grain enlargement effect is a near-complete melting phenomenon that is associated with polycrystalline Si films, and we present a grain boundary melting model to account for this phenomenon. A brief discussion on the apparent similarities and physical differences between the observed phenomenon and the solid state grain growth processes is provided herein.

A New Field-Aided Germanium-Induced Lateral Crystallization of Silicon

2001 ◽  
Vol 664 ◽  
Author(s):  
Kianoush Naeli ◽  
Shamsoddin Mohajerzadeh ◽  
Ali Khakifirooz ◽  
Saber Haji ◽  
Ebrahim A. Soleimani
Keyword(s):  
Electric Field ◽  
Grain Growth ◽  
Negative Electrode ◽  
Crystallization Rate ◽  
Lateral Growth ◽  
Annealing Temperatures ◽  
Lateral Crystallization ◽  
Si Films ◽  
First Time ◽  
Induced Crystallization

ABSTRACTThe effect of an electric field on germanium-seeded lateral crystallization of a-Si is studied for the first time and compared to this effect in Ni-induced lateral growth. While the crystallization rate is lower when Ge is used as the nucleation seed and annealing should be done at higher temperatures, filed-aided crystallization shows a similar behavior to that observed for Ni-induced crystallization. Optical microscopy results indicate that grain growth starting from the negative electrode occurs in Si films at annealing temperatures higher than 480°C, while the applied electric field ranges form 200 to 1400V/cm. SEM was also used to confirm the crystallinity of the films.

Excimer-Laser Crystallization of Patterned Si Films At High Temperatures Via Artificially Controlled Super-Lateral Growth

1995 ◽  
Vol 397 ◽  
Author(s):  
H. Jin Song ◽  
James S. Im
Keyword(s):  
Substrate Temperature ◽  
Single Crystal ◽  
Excimer Laser ◽  
Lateral Growth ◽  
Laser Crystallization ◽  
High Substrate ◽  
Temperature Method ◽  
Main Portion ◽  
Si Films ◽  
Rate Ratios

ABSTRACTBased on the artificially controlled super-lateral growth approach, we have developed a novel excimer-laser-based high-substrate-temperature method for producing single-crystal Si islands on SiO2. By irradiating a photolithographically preconfigured sample, complete melting of an Si film is induced only at precisely predesignated locations within patterned and physically isolated islands. An intentionally incompletely melted section within each island initiates lateral growth of crystalline grains. A “bottleneck” portion of the island permits only one of the laterally growing grains to propagate into the main portion of the island. The low nucleation-to-growth-rate ratios that are attainable with high substrate temperatures (1000–1200 °C) can lead to nearly unlimited lateral growth distances; with a proper combination of the substrate temperature and the island dimension, the main area of an island—up to 50×50 μm2 in area—is readily converted into a large single-crystal region.

Grain Boundary Location-Controlled Polt-Si Films for Tft Devices Obtained Via Novel Excimer Laser Process

1994 ◽  
Vol 358 ◽  
Author(s):  
H. J. Kim ◽  
James S. Im
Keyword(s):  
Grain Boundary ◽  
Excimer Laser ◽  
Crystallization Process ◽  
Critical Distance ◽  
Capping Layer ◽  
Complete Melting ◽  
Boundary Location ◽  
Si Films ◽  
Active Channel ◽  
Induced Crystallization

ABSTRACTBased on a previously acquired physical understanding of the excimer-laser-induced crystallization process, we have developed a new crystallization technique that produces controlled microstructures and possesses a wide processing window. A patterned oxide capping layer was used as an antireflective coating to induce complete melting of an Si film under an SiO2 pattern, and partial melting of the Si film in the areas not under the capping layer—allowing controlled super lateral growth to proceed from the incompletely melted portion of the film to the completely melted portion. For the simple stripes used in this investigation, when the width of the completely molten region is less than a critical distance (above which nucleation of solids occurs in the middle of the completely melted regions), the resulting microstructure has large and elongated grains with one precisely located grain boundary running parallel to the stripe In the middle of the oxide capped region.Arrangement of TFT devices on the resulting Grain boundary Location-Controlled (GLC) Si films with one (or zero) grain boundaries located perpendicular to the flow of electrons within the active channel portion of the TFT devices is illustrated. Such devices are expected to possess performance and uniformity characteristics that are superior to currently available poly-Si TFT devices.

Excimer-Laser Crystallization of Si Films Via Bi-Directional Irradiation of Dual-Layer Films on Transparent Substrates

1995 ◽  
Vol 397 ◽  
Author(s):  
Jung H. Yoon ◽  
James S. Im
Keyword(s):  
Excimer Laser ◽  
Thermal Environment ◽  
Thermal Evolution ◽  
Bottom Layer ◽  
Lateral Growth ◽  
Laser Crystallization ◽  
Projection System ◽  
Substrate Heating ◽  
Excimer Laser Crystallization ◽  
Si Films

ABSTRACTIn this paper, we report on a new excimer-laser crystallization (ELC) method that is highly effective in extending the super-lateral growth (SLG) distance and which does not involve any preheating of the substrate. The technique utilizes bi-directional irradiation of a dual layer Si film stack (separated by an oxide layer) deposited on a quartz wafer. The top layer is irradiated with a projection system which transfers a mask image in order to produce grain-boundary-location-controlled (GLC) regions, and the bottom layer, upon irradiation with a uniform beam, acts as a medium that favorably affects the thermal evolution of the top layer. The technique is effective and attractive in that the heating is spatially and temporally localized in an optimal manner. The thermal environment required for extending the SLG distance, as is induced by the melting and solidification of the bottom layer, is physically regulated by the melting temperature of Si, and the enthalpy difference between liquid and solid can be used to initially store and subsequently release heat. Using the method, we were able to attain GLC regions with widths up to 10 μm in 1000-Å Si films without any substrate heating. We elaborate on the applicability of the method to various artificially controlled super-lateral growth (ACSLG) techniques, and discuss process optimization by means of varying the multilayer configuration.

Observation of super lateral growth in long pulse (170 ns) excimer laser crystallization of a-Si films

2003 ◽  
Vol 427 (1-2) ◽  
pp. 319-323 ◽  
Author(s):  
A. Pecora ◽  
R. Carluccio ◽  
L. Mariucci ◽  
G. Fortunato ◽  
D. Murra ◽  
...  
Keyword(s):  
Excimer Laser ◽  
Lateral Growth ◽  
Laser Crystallization ◽  
Excimer Laser Crystallization ◽  
Si Films ◽  
Long Pulse

Molecular Dynamics Simulations of Nucleation and Crystallization Processes During Excimer-Laser Annealing of Amorphous Silicon on Glass

2003 ◽  
Vol 780 ◽  
Author(s):  
T. Motooka ◽  
S. Munetoh ◽  
Lee Byoung Min ◽  
K. Nisihira
Keyword(s):  
Molecular Dynamics ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Md Simulations ◽  
Lateral Growth ◽  
Crystal Surfaces ◽  
Excimer Laser Annealing ◽  
Crystalline Films ◽  
Dynamics Simulations ◽  
Si Films

AbstractWe have investigated atomistic processes of nucleation and crystallization in excimer-laser annealed thin Si films on glass based on molecular-dynamics (MD) simulations using the Tersoff potential. MD cells composed of up to approximately 50000 Si atoms were heated to produce melted Si, and then melted Si was quenched under various supercooled conditions with or without a temperature gradient and the corresponding nucleation processes were visualized. Lateral growth of thin Si crystalline films was also simulated by embedding a crystalline nano-particle with various crystal surfaces in melted Si. It has been found that the crystal surfaces become predominantly {111} during the lateral growth processes.

Super-lateral-growth regime analysis in long-pulse-duration excimer-laser crystallization of a-Si films on SiO 2

1999 ◽  
Vol 68 (6) ◽  
pp. 631-635 ◽  
Author(s):  
E. Fogarassy ◽  
S. de Unamuno ◽  
B. Prevot ◽  
P. Boher ◽  
M. Stehle ◽  
...  
Keyword(s):  
Pulse Duration ◽  
Excimer Laser ◽  
Lateral Growth ◽  
Laser Crystallization ◽  
Growth Regime ◽  
Excimer Laser Crystallization ◽  
Si Films ◽  
Long Pulse ◽  
Regime Analysis

Non-Equilibrium Two-Dimensional Model of Excimer-Laser Melting and Solidification of Thin Si Films on SiO2

1995 ◽  
Vol 397 ◽  
Author(s):  
Vikas V. Gupta ◽  
H. Jin Song ◽  
James S. Im
Keyword(s):  
Excimer Laser ◽  
Oxide Surface ◽  
Solidification Velocity ◽  
Lateral Growth ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Laser Melting ◽  
Growth Phenomenon ◽  
Melting And Solidification ◽  
Non Equilibrium

ABSTRACTWe have developed a two-dimensional numerical model of excimer-laser melting and solidification that properly takes into account the non-equilibrium and transient nature of the process. The model incorporates a novel explicit finite difference scheme for efficiently solving the heat conduction equation and an algorithm that incorporates the interface response function for properly simulating the evolution of phase domains. The model provides space- and time-resolved information regarding the thermal profile and phase domains from which nearly all of the important solidification details can be extracted (e.g., interface location, solidification velocity, interfacial undercooling, etc.). For the simple partial-melting-and-vertical-regrowth scenario, results from the model converge with the results from the well-established one-dimensional model. As a result of its two-dimensional and non-equilibrium formulation, which also respects the amorphous and inert nature of the underlying oxide surface, the model is unique in its capability for properly simulating those solidification scenarios that involve extensive lateral growth of solids, as for example those behind the super-lateral growth phenomenon and various artificially controlled super-lateral growth processes.

Sign in / Sign up

Export Citation Format

Share Document