A Novel Method for Fabrication of Hyhdrogenated Amorphous Silicon and High Quality Poly-SI Films on the Same Substrate by Employing Excimer Laser

1997 ◽  
Vol 467 ◽  
Author(s):  
Kwon-Young Choi ◽  
Jong-Wook Lee ◽  
Hyoung-Bae Choi ◽  
Jae-Hong Jeon ◽  
Min-Koo Han ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Excimer Laser ◽  
Rapid Thermal Annealing ◽  
Hydrogen Content ◽  
Glass Substrate ◽  
Laser Annealing ◽  
High Mobility ◽  
Halogen Lamp ◽  
Physical Damage ◽  
Excimer Laser Annealing

ABSTRACTWe have fabricated the a-Si:H film for pixel region and poly-Si film for driver region on the same glass substrate by a rapid thermal process successfully. By employing the halogen lamp, the considerable amount of hydrogen in the PECVD a-Si:H film, which causes the undesirable film ablation due to hydrogen evolution during excimer laser annealing, could be reduced selectively in the peripheral driver area where the a-Si:H film is recrystallized into poly-Si film in order to obtain the high mobility. After rapid thermal annealing, the hydrogen content in a-Si:H films, of which the inherent hydrogen content was found to be about 10–12 at. %, is successfully reduced to less than 5 at. %. The annealing conditions for dehydrogenation are 500, 550, 600 and 650 °C with various halogen lamp irradiation period which are below the point of the glass shrinkage. It should be noted that after rapid thermal annealing, any physical damage in the glass substrate has not been observed.

Electrical/Optical Properties of Thin Transparent Oxide Films Deposited Using DC Magnetron Sputtering

2004 ◽  
Vol 449-452 ◽  
pp. 989-992
Author(s):  
Byung Soo So ◽  
Sung Moon Kim ◽  
Young Sin Pyo ◽  
Young Hwan Kim ◽  
Jin-Ha Hwang
Keyword(s):  
Optical Properties ◽  
Magnetron Sputtering ◽  
Thermal Annealing ◽  
Excimer Laser ◽  
Indium Tin Oxide ◽  
Laser Annealing ◽  
Dc Magnetron Sputtering ◽  
Excimer Laser Annealing ◽  
Plastic Substrates ◽  
Ito Thin Films

Amorphous indium tin oxide (ITO) thin films were grown on plastic substrates, PES (polyethersulfone) using low temperature DC magnetron sputtering. Various post-annealing techniques are attempted to optimize conductivity, transmittance, and roughness: i) conventional thermal annealing, ii) excimer laser annealing, and iii) UV irradiation. The electrical/optical properties were measured using Hall-measurement, DC 4-point resistance measurement, and UV spectrometry along with micro-structural characterization. Optimized UV treatment exhibits enhanced conductivity and smooth surface, compared to those of conventional thermal annealing and excimer laser annealing.

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.

The Two-Step Rapid Thermal Annealing Effect of the Prepatterned A-SI Films

1998 ◽  
Vol 525 ◽  
Author(s):  
Kee-Chan Park ◽  
Kwon-Young Choi ◽  
Min-Cheol Lee ◽  
Min-Koo Han ◽  
Chan-Eui Yoon
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Glass Substrate ◽  
Polycrystalline Silicon ◽  
Chemical Vapor ◽  
Heat Propagation ◽  
Halogen Lamp ◽  
Si Films ◽  
Hydrogenated Amorphous ◽  
Temperature Crystallization

ABSTRACTHydrogenated amorphous silicon (a-Si:H) films which were deposited by plasma enhanced chemical vapor deposition (PECVD) have been recrystallized by the two-step rapid thermal annealing (RTA) employing the halogen lamp. The a-Si:H films evolve hydrogen explosively during the high temperature crystallization step. In result, the recrystallized polycrystalline silicon (poly-Si) films have poor surface morphology. In order to avoid the hydrogen evolution, the films have undergone the dehydrogenation step prior to the crystallization step.Before the RTA process, the active area of thin film transistors (TFT's) was patterned. The prepatterning of the a-Si:H active islands may reduce the thermal damage to the glass substrate during the recrystallization. The computer generated simulation shows the heat propagation from the a-Si:H islands into the glass substrate. We have fabricated the poly-Si TFT's on silicon wafers. The maximum ON/OFF current ratio of the devices was over 10.

XeCl Excimer Laser Annealing Used to Fabricate Poly-Si Tfts

1986 ◽  
Vol 71 ◽  
Author(s):  
T. Sameshima ◽  
S. Usui
Keyword(s):  
Energy Density ◽  
Excimer Laser ◽  
Glass Substrate ◽  
Laser Annealing ◽  
Processing Temperature ◽  
Excimer Laser Annealing ◽  
Channel Mobility ◽  
First Time ◽  
Xecl Excimer Laser

AbstractMo-gate n-channel poly-Si TFTs have been fabricated for the first time at a low processing temperature of 26°C. 500 to 1000A thick a-Si:H was successfully crystallized by pulsed XeCl excimer laser (308nm) annealing without heating the glass substrate. The channel mobility of the TFT was 180 cm2/V.sec when the a-Si:H was annealed at energy density of 200 mJ/cm2.

scholarly journals Crystallization of Amorphous Silicon via Excimer Laser Annealing and Evaluation of Its Passivation Properties

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3335
Author(s):  
Sanchari Chowdhury ◽  
Jinsu Park ◽  
Jaemin Kim ◽  
Sehyeon Kim ◽  
Youngkuk Kim ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Thermal Annealing ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Laser Energy ◽  
Ultra Violet ◽  
Uv Laser ◽  
Excimer Laser Annealing ◽  
Cell Efficiency ◽  
Deep Uv

The crystallization of hydrogenated amorphous silicon (a-Si:H) is essential for improving solar cell efficiency. In this study, we analyzed the crystallization of a-Si:H via excimer laser annealing (ELA) and compared this process with conventional thermal annealing. ELA prevents thermal damage to the substrate while maintaining the melting point temperature. Here, we used xenon monochloride (XeCl), krypton fluoride (KrF), and deep ultra-violet (UV) lasers with wavelengths of 308, 248, and 266 nm, respectively. Laser energy densities and shot counts were varied during ELA for a-Si:H films between 20 and 80 nm thick. All the samples were subjected to forming gas annealing to eliminate the dangling bonds in the film. The ELA samples were compared with samples subjected to thermal annealing performed at 850–950 °C for a-Si:H films of the same thickness. The crystallinity obtained via deep UV laser annealing was similar to that obtained using conventional thermal annealing. The optimal passivation property was achieved when crystallizing a 20 nm thick a-Si:H layer using the XeCl excimer laser at an energy density of 430 mJ/cm2. Thus, deep UV laser annealing exhibits potential for the crystallization of a-Si:H films for TOPCon cell fabrication, as compared to conventional thermal annealing.

H and Au diffusion in high mobility a-InGaZnO thin-film transistors via low temperature KrF excimer laser annealing

2017 ◽  
Vol 110 (13) ◽  
pp. 133503 ◽  
Author(s):  
Juan Paolo S. Bermundo ◽  
Yasuaki Ishikawa ◽  
Mami N. Fujii ◽  
Hiroshi Ikenoue ◽  
Yukiharu Uraoka
Keyword(s):  
Thin Film ◽  
Low Temperature ◽  
Excimer Laser ◽  
Thin Film Transistors ◽  
Laser Annealing ◽  
High Mobility ◽  
Excimer Laser Annealing ◽  
Krf Excimer Laser

Low-Temperature Poly-Si TFT by Excimer Laser Annealing

2001 ◽  
Vol 685 ◽  
Author(s):  
Tohru Nishibe
Keyword(s):  
Low Temperature ◽  
Excimer Laser ◽  
Present State ◽  
Glass Substrate ◽  
Laser Annealing ◽  
Value Added ◽  
Gate Insulator ◽  
Excimer Laser Annealing ◽  
Low Temperature Process

AbstractPoly-Si TFT-LCD has begun its way to an advanced display by integrating the driver circuits onto the glass substrate. Improvement of poly-Si TFT is essential in order to achieve value-added display where circuits for various functions are integrated on one substrate. This report the concept of poly-Si TFT display from present state to future scope, and required technologies for each generation. It will also focus on technologies such as crystallization and gate insulator formation at low temperature process.

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