Crystallization of Amorphous Silicon Thin Films by Microwave Heating

2014 ◽  
Vol 1666 ◽  
Author(s):  
Tomohiko Nakamura ◽  
Shinya Yoshidomi ◽  
Masahiko Hasumi ◽  
Toshiyuki Sameshima ◽  
Tomohisa Mizuno

ABSTRACTWe report crystallization of amorphous silicon (a-Si) thin films and improvement of thin film transistors (TFTs) characteristics using 2.45 GHz microwave heating assisted with carbon powders. Undoped 50-nm-thick a-Si films were formed on quartz substrates and heated by microwave irradiation for 2, 3, and 4 min. Raman scattering spectra revealed that the crystalline volume ratio increased to 0.42 for the 4-min heated sample. The dark and photo electrical conductivities measured by Air mass 1.5 at 100 mW/cm2 were 2.6x10-6 and 5.2x10-6 S/cm in the case of 4-min microwave heating followed by 1.3x106-Pa-H2O vapor heat treatment at 260°C for 3 h. N channel polycrystalline silicon TFTs characteristics were improved by the combination of microwave heating with high-pressure H2O vapor heat treatment. The threshold voltage decreased from 5.3 to 4.2 V and the effective carrier mobility increased from 18 to 25 cm2/Vs.

1996 ◽  
Vol 441 ◽  
Author(s):  
Byung-Il Lee ◽  
Kwang-Ho Kim ◽  
Won-Cheol Jeong ◽  
Pyung-Su Ahn ◽  
Jin-Wook Shin ◽  
...  

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.


2008 ◽  
Vol 516 (5) ◽  
pp. 600-603 ◽  
Author(s):  
Keisuke Ohdaira ◽  
Yuki Abe ◽  
Makoto Fukuda ◽  
Shogo Nishizaki ◽  
Noritaka Usami ◽  
...  

1992 ◽  
Vol 283 ◽  
Author(s):  
L. Lusson ◽  
P. Elkaim ◽  
M. Cuniot ◽  
D. Ballutaud ◽  
R. Rizk ◽  
...  

ABSTRACTSuccessive deuterium diffusion and effusion experiments are performed on undoped microcrystalline silicon obtained from thermally crystallized sputtered amorphous silicon thin films. The effect of prior incorporation of deuterium during the amorphous film growth on the crystallization mechanism and on the microcrystalline film quality is probed by the use of the post hydrogenation procedure. In connection with the deuterium solubility as provided by secondary ion mass spectroscopy (SIMS) profiling, the analysis of the effusion spectra suggests the existence of large cavities in the crystallized a-Si:D films, containing most probably molecular hydrogen. They are absent in the corresponding crystallized non-deuterated a-Si films. Other deuterium configurations seem to be present in both kinds of samples such as weakly bonded deuterium in small clusters and at grain boundaries.


1997 ◽  
Vol 471 ◽  
Author(s):  
Jeong No Lee ◽  
Yoon Chang Kim ◽  
Yong Woo Choi ◽  
Byung Tae Ahn

ABSTRACTMicrowave heating was utilized for the first time for solid phase crystallization of amorphous silicon films. Microwave heating lowered annealing temperature and reduced the annealing time for complete crystallization. For example, the amorphous silicon film deposited at 400 °C was fully crystallized in 3 h at 550 °C below which glass is available as a substrate. On microwave heating, the hydrogen in the amorphous films diffused out very quickly, but there was no change in structural disorder following hydrogen evolution. The lower temperature crystallization of a-Si films compared to conventional furnace annealing is due to the interaction between microwave and silicon atoms. The grain size of the crystallized silicon films was in the range of 0.55 to 0.78 μm, depending on the deposition temperature. These grain sizes are not so small comparing those of Si films by conventional furnace heating, while the crystallization processing time is much shorter.


Author(s):  
R. M. Anderson

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.


2003 ◽  
Vol 762 ◽  
Author(s):  
Hwang Huh ◽  
Jung H. Shin

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)


2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Lukas Terkowski ◽  
Iain W. Martin ◽  
Daniel Axmann ◽  
Malte Behrendsen ◽  
Felix Pein ◽  
...  

2020 ◽  
Vol 984 ◽  
pp. 91-96
Author(s):  
Cheng Liu ◽  
Yu Hao Song ◽  
Dong Yang Li ◽  
Wei Li

The structural and optical properties of amorphous silicon (a-Si) and Al-dispersed amorphous silicon (a-Si:Al) thin films irradiated by femtosecond (fs) laser at various energy densities are investigated comparatively in this article. It is found that there is an uneven crystallization in both amorphous thin films by means of optical microscopy and laser Raman spectroscopy respectively. The crystallization in each pulse spot area is gradually weakened from the center to the edge along with the energy dispersion of laser irradiation. The laser induced crystallization in a-Si thin films begins early and develops more extensively compared to that in a-Si:Al thin films, and Al nanoparticles inhibit somehow the crystallization of a-Si in a-Si:Al thin films.


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