A method to evaluate explosive crystallization velocity of amorphous silicon films during flash lamp annealing

2014 ◽  
Vol 92 (7/8) ◽  
pp. 718-722 ◽  
Author(s):  
Keisuke Ohdaira
Keyword(s):  
Film Thickness ◽  
Amorphous Silicon ◽  
High Speed ◽  
Flash Lamp ◽  
Periodic Modulation ◽  
Emission Frequency ◽  
Explosive Crystallization ◽  
Lateral Crystallization ◽  
Si Films ◽  
The Relationship

Flash lamp annealing (FLA) of micrometre-order thick amorphous silicon (a-Si) films can induce explosive crystallization (EC), high-speed lateral crystallization driven by the release of latent heat. We develop multipulse FLA system, which emits a quasi-millisecond pulse consisting of a number of subpulses. The emission frequency of the subpulses can be systematically controlled, and the emission of subpulses leads to the periodic modulation of the temperature of a Si film and the resulting formation of macroscopic stripe patterns. The relationship between a subpulse emission frequency and the width of the macroscopic stripe patterns yields EC velocity. Two kinds of EC modes can be observed, depending on the methods of precursor a-Si deposition and (or) a-Si film thickness.

Formation of Large, Orientation-Controlled, Nearly Single Crystalline Si Thin Films on SiO2 Using Contact Printing of Rolled and Annealed Nickel Tapes

2003 ◽  
Vol 762 ◽  
Author(s):  
Hwang Huh ◽  
Jung H. Shin
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
High Resolution ◽  
Amorphous Silicon ◽  
Tem Analysis ◽  
Contact Printing ◽  
Single Crystalline ◽  
High Resolution Tem ◽  
Lateral Crystallization ◽  
Si Films

AbstractAmorphous silicon (a-Si) films prepared on oxidized silicon wafer were crystallized to a highly textured form using contact printing of rolled and annealed nickel tapes. Crystallization was achieved by first annealing the a-Si film in contact with patterned Ni tape at 600°C for 20 min in a flowing forming gas (90 % N2, 10 % H2) environment, then removing the Ni tape and further annealing the a-Si film in vacuum for2hrsat600°C. An array of crystalline regions with diameters of up to 20 μm could be formed. Electron microscopy indicates that the regions are essentially single-crystalline except for the presence of twins and/or type A-B formations, and that all regions have the same orientation in all 3 directions even when separated by more than hundreds of microns. High resolution TEM analysis shows that formation of such orientation-controlled, nearly single crystalline regions is due to formation of nearly single crystalline NiSi2 under the point of contact, which then acts as the template for silicide-induced lateral crystallization. Furthermore, the orientation relationship between Si grains and Ni tape is observed to be Si (110) || Ni (001)

Critical Laser Fluence Observed in (111) Texture, Grain Size and Mobility of Laser Crystallized Amorphous Silicon

1993 ◽  
Vol 297 ◽  
Author(s):  
R.I. Johnson ◽  
G.B. Anderson ◽  
J.B. Boyce ◽  
D.K. Fork ◽  
P. Mei ◽  
...  
Keyword(s):  
Grain Size ◽  
Film Thickness ◽  
Substrate Temperature ◽  
Amorphous Silicon ◽  
Laser Fluence ◽  
Laser Energy ◽  
X Ray ◽  
Peak Intensity ◽  
Silicon Materials ◽  
The Relationship

This paper describes new results on the relationship between the grain size, mobility, and Si (111) x-ray peak intensity of laser crystallized amorphous silicon as a function of the laser fluence, shot density, substrate temperature, and film thickness. These observations include an unexpected narrow peak found in the silicon (111) x- ray peak intensity, which occurs at a specific laser fluence for a given film thickness and substrate temperature. Amorphous silicon materials processed at laser energy densities defined by this peak exhibit exceptionally large grain sizes and electron mobilities that cannot be obtained at any other energy and shot density combination above or below the energy at which the Si (111) x-ray peak intensity maximum occurs.

A Study on the Metal Induced Lateral Crystallization Behavior of Amorphous Silicon Thin Films

1996 ◽  
Vol 441 ◽  
Author(s):  
Byung-Il Lee ◽  
Kwang-Ho Kim ◽  
Won-Cheol Jeong ◽  
Pyung-Su Ahn ◽  
Jin-Wook Shin ◽  
...  
Keyword(s):  
Thin Films ◽  
Amorphous Silicon ◽  
Crystallization Behavior ◽  
Crystallization Rate ◽  
External Stress ◽  
Tem Analysis ◽  
Silicon Thin Films ◽  
Amorphous Si ◽  
Lateral Crystallization ◽  
Si Films

AbstractBasic mechanisms for both Ni- and Pd-metal induced lateral crystallization (MILC) are investigated. For both cases, tiny silicides were formed under the metal deposited area, and propagated toward amorphous Si films leaving crystallized Si behind at temperatures as low as 500 °C. Ni-MILC was influenced by Pd such that the lateral crystallization rate was enhanced, and the temperature for the lateral crystallization was lowered to 450 °C. Through TEM analysis and external stress experiments, it was found that the enhancement of the lateral crystallization rate was closely related to the compressive stress generated by the formation of nearby Pd2Si.

scholarly journals Crystallization of optically thick amorphous silicon films by near-IR femtosecond laser processing

2020 ◽  
Author(s):  
Kirill Bronnikov ◽  
Alexander Dostovalov ◽  
Artem Cherepakhin ◽  
Eugeny Mitsai ◽  
Alexander Nepomniaschiy ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Amorphous Silicon ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Visible Spectral Range ◽  
Ir Radiation ◽  
Optical Elements ◽  
Near Ir ◽  
Lateral Crystallization ◽  
Si Films

Amorphous silicon (α-Si) film present an inexpensive and promising material for optoelectronic and nanophotonic applications. Its basic optical and optoelectronic properties are known to be improved via phase transition from amorphous to polycrystalline phase. Infrared femtosecond laser radiation can be considered as a promising nondestructive and facile way to drive uniform in-depth and lateral crystallization of α-Si films that are typically opaque in UV-visible spectral range. However, so far only a few studies reported on utilization of near-IR radiation for laser-induced crystallization of α-Si providing no information regarding optical properties of the resultant polycrystalline Si films. The present work demonstrates efficient and gentle single-pass crystallization of α-Si films induced by their direct irradiation with near-IR femtosecond laser pulses coming at sub-MHz repetition rate. Comprehensive analysis of morphology and composition of laser-annealed films by atomic-force microscopy, optical, micro-Raman and energy-dispersive X-ray spectroscopy, as well as numerical modeling of optical spectra, confirmed efficient crystallization of α-Si and high-quality of the obtained films. Moreover, we highlight localized laser-driven crystallization of α-Si as a promising way for optical information encryption, anti-counterfeiting and fabrication of micro-optical elements.

The Effects of Cu on Field Aided Lateral Crystallization (FALC) of Amorphous Silicon (a-Si) Films

2001 ◽  
Vol 664 ◽  
Author(s):  
Jae-Bok Lee ◽  
Chul-Ho Kim ◽  
Se-Youl Kwon ◽  
Duck-Kyun Choi
Keyword(s):  
Electric Field ◽  
Amorphous Silicon ◽  
Applied Field ◽  
Polycrystalline Silicon ◽  
Annealing Temperature ◽  
Negative Electrode ◽  
Free Region ◽  
Lateral Crystallization ◽  
Novel Concept ◽  
Si Films

ABSTRACTA novel concept of field aided lateral crystallization (FALC) and the effects of Cu on FALC of amorphous silicon (a-Si) were investigated. Cu was found to induce the lateral crystallization toward a metal-free region as well as the crystallization of a-Si in contact with Cu. In particular, the lateral crystallization caused by Cu was noticeably accelerated at the negative electrode side in every pattern with an aid of electric field, while it was retarded at the positive electrode side. The occurrence of Cu-FALC phenomenon was interpreted in terms of dominant diffusing species (DDS) in the reaction between metal and Si. The FALC velocity increased with the applied field intensity and the annealing temperature. The crystallization of a-Si was achieved at temperatures as low as 375°C when the annealing time increased in the presence of high electric field, above 30V/cm. Therefore, we could demonstrate the possibility of low temperature (<500°C) polycrystalline silicon (poly-Si) crystallization using Cu as a mediator in FALC technology.

Intrinsic Stress and Microstructural Evolution in Sputtered Nanometer Single and Multilayered Films

1994 ◽  
Vol 343 ◽  
Author(s):  
Tai D. Nguyen
Keyword(s):  
Film Thickness ◽  
Microstructural Evolution ◽  
Thin Layers ◽  
Intrinsic Stress ◽  
Working Pressure ◽  
Compressive Stresses ◽  
Columnar Grain ◽  
Si Films ◽  
Relationship Of ◽  
The Relationship

ABSTRACTThe relationship of intrinsic stress and microstructural evolution in nanometer thick Mo and Si films, and Mo/Si multilayers deposited by magnetron sputtering at low working pressure (2.5 mTorr) is studied. The stress depends strongly on the microstructure which evolves with the film thickness. Transition from tensile to compressive films is observed in the metal films, in which nucleation and columnar grain growth occur. Deposition of layered Mo films by time-delayed sequential sputtering of thin layers results in smaller grains that do not extend through the film thickness, and in more tensile stress state than thick films of trie same thickness. The Si films are highly compressive at all thicknesses studied. The multilayers in this study show compressive stresses, with higher compressive stress at longer periods, and decreasing stress at shorter periods. The interface stress in amorphous Mo/Si multilayers is determined to be 1.1 J/m2. Comparison with values in other systems is made.

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