Lateral Grain Growth in the Excimer Laser Crystallization of Poly-Si

1994 ◽  
Vol 321 ◽  
Author(s):  
H. Kuriyama ◽  
K. Sano ◽  
S. Ishida ◽  
T. Nohda ◽  
Y. Aya ◽  
...  
Keyword(s):  
Grain Size ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Field Effect Mobility ◽  
Laser Crystallization ◽  
Excimer Laser Annealing ◽  
Short Processing Time ◽  
Low Temperature Processing ◽  
Excimer Laser Crystallization ◽  
Annealing Method

ABSTRACTWe have succeeded in obtaining nondoped, thin poly-Si film (thickness ∼500Å) with excellent crystallinity and large grain size (Maximum grain size ∼4.5 μ m) by an excimer laser annealing Method, which offers the features of low-temperature processing and a short processing time. The grain size distribution shrinks in the region around 1.5 μ m and this poly-Si film exhibits a strong (111) crystallographic orientation. Poly-Si thin film transistors using these films show quite a high field effect mobility of 440cm2/V · s below 600°C process.

Experimental Analysis for Low-Temperature Poly-Si Films Produced by Using the Excimer Laser Annealing Method

2006 ◽  
Vol 505-507 ◽  
pp. 277-282 ◽  
Author(s):  
Yu Ru Chen ◽  
Long Sun Chao
Keyword(s):  
Grain Size ◽  
Excimer Laser ◽  
Glass Substrate ◽  
Laser Annealing ◽  
Pulse Number ◽  
Sio2 Layer ◽  
Excimer Laser Annealing ◽  
Melt Pool ◽  
Si Films ◽  
Annealing Method

This paper is to investigate the effects on grain size of different working conditions for making poly Si films by using the excimer laser annealing method. In this research, a KrF excimer laser of 248 nm in wavelength is used to irradiate a-Si films of 0.1 μm in thickness on glass substrate to produce poly-Si ones. The control parameters are laser intensity (200~500 mJ/cm2), pulse number (1~10 shots) and coverage fraction (0~100%). Besides, the effect of a SiO2 layer is also studied, which is utilized as a heat-isolated zone located between the Si film and glass substrate. Average grain sizes from SEM photos are used to analyze the effects of these parameters. Purely from the heat transfer view, the Si film obtains more energy would have the slower cooling or solidification rate, which results in the larger grain. From the experimental results, if the melt pool is within the range of Si film or does not contact its neighboring layer (SiO2 layer or glass substrate), the more absorbed energy from the higher energy intensity, the larger pulse number or the bigger coverage fraction can have the larger average grain size. However, with large enough energy, the melt pool could go through the Si film and touch the lower layer. This would induce much more nuclei due to the homogeneous nucleation in the pool and the heterogeneous nucleation near the interface between the film and the neighboring layer. The resulting grain size is much smaller than that of the former one. The transition points of these two cases for different control parameters can be obtained from the experimental results in this study. When the energy from the laser is small, the SiO2 layer acts like a heat absorber and makes the grain size smaller than that of not having the SiO2 layer. On the other hand, when the energy is large, the SiO2 layer becomes a heat insulator and makes the grain size larger.

Bottom-Gate Thin-Film Transistors Fabricated by Excimer Laser Annealing

2013 ◽  
Vol 811 ◽  
pp. 177-180
Author(s):  
Jyh Liang Wang ◽  
Chun Chien Tsai ◽  
Chuan Chou Hwang ◽  
Tsang Yen Hsieh
Keyword(s):  
Thin Film ◽  
Excimer Laser ◽  
Thin Film Transistors ◽  
High Performance ◽  
Laser Annealing ◽  
Electrical Characteristics ◽  
Laser Crystallization ◽  
Excimer Laser Annealing ◽  
Excimer Laser Crystallization ◽  
Bottom Gate

High performance and device uniformity n-channel low-temperature poly-silicon (LTPS) bottom-gate (BG) thin film transistors (TFTs) with artificially-controlled lateral grain growth have been performed by excimer laser crystallization (ELC). The BG TFTs (W/L = 1.5 μm/1.5 μm) demonstrate field-effect-mobility of 323 cm2/Vs and high Ion/Ioff of 9.5 × 108. The proposed BG TFTs reveal the superior electrical characteristics, device uniformity, and reliability than conventional top-gate ones.

Si. I-x-y. GexCy Film Formation by Pulsed Excimer Laser Crystallization of Heavily Ge and C Implanted Silicon

1994 ◽  
Vol 354 ◽  
Author(s):  
E. Fogarassy ◽  
D. Dentel ◽  
JJ. Grob ◽  
B. Prévot ◽  
J.P. Stoquert ◽  
...  
Keyword(s):  
Excimer Laser ◽  
Initial Dose ◽  
Laser Annealing ◽  
Film Formation ◽  
Silicon Substrates ◽  
Laser Crystallization ◽  
Excimer Laser Annealing ◽  
Excimer Laser Crystallization ◽  
First Time

AbstractWe investigate, for the first time, the possibility to crystallize heavily Ge and C implanted silicon substrates by excimer-laser annealing performed in the molten regime. It is demonstrated that the crystalline quality of the laser grown SiGeC alloys strongly depends on the initial dose of implanted carbon.

Excimer Laser Annealing of Amorphous Silicon Films

1994 ◽  
Vol 336 ◽  
Author(s):  
J. Viatella ◽  
R.K. Singh ◽  
R.P.S. Thakur
Keyword(s):  
Grain Size ◽  
Amorphous Silicon ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Silicon Layer ◽  
Solidification Velocity ◽  
Excimer Laser Annealing ◽  
Active Matrix ◽  
Average Temperature ◽  
Low Temperature Processing

ABSTRACTLow temperature processing is necessary for the fabrication of thin-film transistors for electronics-on-glass applications, including active matrix flat-panel displays. One method to achieve this involves the use of pulsed excimer-laser annealing of an Amorphous silicon layer on top of an SiO2 layer. The intense UV laser is absorbed in the Amorphous silicon region, Maintaining a low average temperature. The thickness of the underlying SiO2 layer affects the solidification velocity and hence the grain size of the annealed layer. Previous work has concluded that the resultant grain size is small (<100 nm) and further work is needed in finding ways of increasing grain size. This paper describes how grain size is affected by varying the thickness of the SiO2 layer. Correlations will be discussed.between the solidification velocities and grain size as affected by the varying thickness of the SiO2 layer. The paper includes a comparison between experimental and theoretical results, using equations based on energy balance considerations.

Large-Grain Doped Poly-Si Films Fabricated Using New Excimer Laser Annealing Technique

1992 ◽  
Vol 283 ◽  
Author(s):  
Hiroshi Iwata ◽  
Tomoyuki Nohda ◽  
Satoshi Ishida ◽  
Takashi Kuwahara ◽  
Keiichi Sano ◽  
...  
Keyword(s):  
Grain Size ◽  
Sheet Resistance ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Solidification Velocity ◽  
Excimer Laser Annealing ◽  
Arf Excimer Laser ◽  
Si Films

ABSTRACTThe grain size of phosphorous (P)-doped poly-Si film has been enlarged to about 5000 Å by controlling the solidification velocity of molten Si during ArF excimer laser annealing. The drastically enlarged grain has few defects inside the grain. It has been confirmed that control of the solidification velocity is effective for P-doped poly-Si similar to the case of non-doped poly-Si films. In addition, a sheet resistance of 80 Ω/□ (ρ = 4 × 10-4 Ω · cm) has been achieved for very thin (500 Å) films by recrystallizing PECVD P-doped a-Si films.

Enlargement of Grain Size and Location Control of Grain in Excimer-laser Crystallization of Si Film

2006 ◽  
Vol 910 ◽  
Author(s):  
Wenchang Yeh ◽  
Dunyuan Ke ◽  
Chunjun Zhuang
Keyword(s):  
Grain Size ◽  
Light Beam ◽  
Excimer Laser ◽  
Conventional Method ◽  
Growth Process ◽  
Laser Annealing ◽  
Glass Structure ◽  
Control Technique ◽  
Back Side ◽  
Excimer Laser Annealing

AbstractA technique for enlargement of grain size were shown and a technique for location controlled super lateral growth (SLG) grain in excimer laser annealing (ELA) were proposed and realized. In the technique for grain size enlargement, the grain size was enlarged to 10£gm that is more than 10 times larger than that in conventional method(~0.8£gm). The proposed sample structure was Si film/light absorptive film/Glass structure with applying the laser light from the back side of glass substrate. Time resolved(~1ns) optical measurement (TROM) revealed that the melt duration of Si film was increased to 800ns that is also 10 times longer than that in conventional method. As for the grain location control technique, a new method contains pre seeding process and post growth process were proposed and realized. In the pre seeding process, micro light beam(£g-light beam) was exposed to Si film to form a grain within the crystallized spot. £g-light beam was formed by micro-lens-array(MLA). After post growth process, single grain array with the diameters of 6£gm was formed in a period of 10£gm.

Low-Temperature Polycrystalline Silicon Thin-Film Transistors and Circuits on Flexible Substrates

MRS Bulletin ◽  
2006 ◽  
Vol 31 (6) ◽  
pp. 461-465 ◽  
Author(s):  
P.C. van der Wilt ◽  
M.G. Kane ◽  
A.B. Limanov ◽  
A.H. Firester ◽  
L. Goodman ◽  
...  
Keyword(s):  
Excimer Laser ◽  
Laser Annealing ◽  
Defect Density ◽  
Solid Phase ◽  
Flexible Substrates ◽  
Full Potential ◽  
Laser Crystallization ◽  
Silicon Thin Film ◽  
Excimer Laser Annealing ◽  
Si Films

AbstractLow-defect-density polycrystalline Si on flexible substrates can be instrumental in realizing the full potential of macroelectronics. Direct deposition or solid-phase crystallization techniques are often incompatible with polymers and produce materials with high defect densities. Excimer-laser annealing is capable of producing films of reasonable quality directly on polymer and metallic substrates. Sequential lateral solidification (SLS) is an advanced pulsed-laser-crystallization technique capable of producing Si films on polymers with lower defect density than can be obtained via excimer-laser annealing. Circuits built directly on polymers using these SLS films show the highest performance reported to date.

Enlargement of Poly-Si Film Grain Size by Excimer Laser Annealing and Its Application to High-Performance Poly-Si Thin Film Transistor

1991 ◽  
Vol 30 (Part 1, No. 12B) ◽  
pp. 3700-3703 ◽  
Author(s):  
Hiroyuki Kuriyama ◽  
Seiichi Kiyama ◽  
Shigeru Noguchi ◽  
Takashi Kuwahara ◽  
Satoshi Ishida ◽  
...  
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Excimer Laser ◽  
High Performance ◽  
Laser Annealing ◽  
Thin Film Transistor ◽  
Excimer Laser Annealing ◽  
Si Thin Film

A Novel Excimer Laser Crystallization Method of Poly-Si Thin Film by Grid Line Electron Beam Irradiation

1999 ◽  
Vol 557 ◽  
Author(s):  
C-M Park ◽  
M-C Lee ◽  
J-H Jeon ◽  
M-K Han
Keyword(s):  
Thin Film ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Ion Beam ◽  
Growth Effect ◽  
Beam Irradiation ◽  
Laser Crystallization ◽  
Excimer Laser Annealing ◽  
Transmission Electron ◽  
Si Thin Film

AbstractExcimer laser annealing technique is proposed to increase the grain size and controlling the microstructure of polycrystalline silicon (poly-Si) thin film. Our method is based on the lateral grain growth during laser annealing. Our specific grid ion beam irradiation method was designed to maximize the lateral growth effect and arrange the location of grain boundaries. We observed well-arranged poly-Si grains up to micrometer order by transmission electron microscopy (TEM).

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