Excimer (XeCl) Laser Annealing of PbZr0.4Ti0.6O3 Thin Film at Low Temperature for TFT FeRAM Application

2004 ◽  
Vol 830 ◽  
Author(s):  
W. X. Xianyu ◽  
H. S. Cho ◽  
J. Y. Kwon ◽  
H.X. Yin ◽  
T. Noguchi
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Energy Density ◽  
Laser Irradiation ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Laser Energy ◽  
Perovskite Phase ◽  
Hysteresis Loops ◽  
Xecl Laser

ABSTRACTIn this study, we successfully produced PbZr0.4Ti0.6O3 (PZT (40/60)) thin films with high crystallinity and high remnant polarization (Pr) at low process temperatures using pulsed excimer (XeCl) laser irradiation. In our experiments, amorphous PZT films were prepared on Pt/Ti/SiO2/Si substrates by a sol-gel method. A two-step process was used to crystallize the amorphous thin films: the films were annealed at 550°C for 10 min to initiate the nucleation of the PZT perovskite phase, and then annealed with an excimer laser heating at 400°C in a 120 Torr nitrogen gas atmosphere. Laser energy density was varied from 150 to 750 mJ/cm2 per pulse. x-ray diffraction (XRD) patterns show that 150–200 mJ/cm2 range multi-shot excimer laser irradiation drastically improved the crystallinity of the PZT perovskite phase, and FESEM photographs show that the PZT thin film has uniform-sized crystal grains. The ferroelectric properties were found to depend on the laser energy density and shot number. Before the laser annealing, the films show hysteresis loops with low Pr and the loops do not saturate. After laser annealing, the films show highly saturated hysteresis loops, with the Pr increasing from 2.2 μC/cm2 to 23.0 μC/cm2. We also propose a new technology for fabrication of thin film transistor (TFT)-driven FeRAM devices on arbitrary insulator substrate such as on glass.

Effect of Excimer Laser Annealing on Optical Properties of GaN Films Deposited by R.F. Magnetron Sputtering

2001 ◽  
Vol 693 ◽  
Author(s):  
Man Young Sung ◽  
Woong-Je Sung ◽  
Yong-Il Lee ◽  
Chun-Il Park ◽  
Woo-Boem Choi ◽  
...  
Keyword(s):  
Thin Films ◽  
Energy Density ◽  
Magnetron Sputtering ◽  
Buffer Layer ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Laser Energy ◽  
Laser Energy Density ◽  
Excimer Laser Annealing ◽  
Zno Buffer Layer

Abstract:GaN thin films on sapphire were grown by RF magnetron sputtering with ZnO buffer layer. The tremendous mismatch between the lattices of GaN and sapphire can be partly overcome by the use of thin buffer layer of ZnO. The dependence of GaN film quality on ZnO buffer layer was investigated by X-ray diffraction(XRD). The properties of the sputtered GaN are strongly dependent on ZnO buffer layer thickness. The optimum thickness of ZnO buffer layer is around 30nm. Using XRD analysis, we have found the optimal substrate temperature which can grow high quality GaN thin film. In addition, the effect of excimer laser annealing(ELA) on structural and electrical properties of GaN thin films was investigated. The surface roughness and images according to the laser energy density were investigated by atomic force microscopy(AFM) and it was confirmed that the crystallization was improved by increasing laser energy density.

Aligned Polycrystalline Silicon Array Thin Film by XeCl Excimer Laser Annealing for AMOLED Displays

2007 ◽  
Vol 124-126 ◽  
pp. 371-374 ◽  
Author(s):  
C.N. Chen ◽  
G.M. Wu ◽  
W.S. Feng
Keyword(s):  
Thin Film ◽  
Energy Density ◽  
Excimer Laser ◽  
Polycrystalline Silicon ◽  
Laser Annealing ◽  
Laser Energy ◽  
Annealing Atmosphere ◽  
Excimer Laser Annealing ◽  
Overlap Ratio ◽  
Xecl Excimer Laser

Low temperature polycrystalline silicon (LTPS) thin film transistors (TFTs) are demanded to fabricate high performance liquid crystal displays (LCD) and organic light-emitting diode displays (OLED). The mobility of poly-Si TFT can be two orders of magnitude higher than that of amorphous Si (a-Si) TFT. Excimer laser annealing has been studied to be the most promising technology to meet the stringent requirement in high speed operation. The process parameters were identified as a-Si thickness, laser energy density, overlap ratio, annealing atmosphere and pre-clean condition. The a-Si layer of 40-50 nm was deposited by plasma enhanced chemical vapor deposition (PECVD). The XeCl excimer laser was irradiated on the a-Si film at room temperature under N2 or N2/O2 environment. The energy density ranged 250-400 mJ/cm2, and the overlap ratio was 95-99%. The highly aligned poly-Si array thin film could be obtained. The grain size has been about 0.31x0.33 μm2, and the regular arrangement in poly-Si grains was discussed. In addition, the PMOS TFT has been fabricated from the aligned poly-Si array. The mobility was as high as 100 cm2/Vs and the sub-threshold swing was around 0.24 V/dec. The threshold voltage was -1.25 V and the on/off current ratio was about 106.

Pulsed Excimer Laser Processing of AlN/GaN Thin Films

1996 ◽  
Vol 449 ◽  
Author(s):  
W. S. Wong ◽  
L. F. Schloss ◽  
G.S. Sudhir ◽  
B. P. Linder ◽  
K-M. Yu ◽  
...  
Keyword(s):  
Thin Films ◽  
Energy Density ◽  
Excimer Laser ◽  
Laser Processing ◽  
Laser Annealing ◽  
Rutherford Backscattering Spectrometry ◽  
Pulsed Laser ◽  
Emission Peak ◽  
Dopant Activation ◽  
Pulsed Laser Annealing

ABSTRACTA KrF (248 nm) excimer laser with a 38 ns pulse width was used to study pulsed laser annealing of AIN/GaN bi-layers and dopant activation of Mg-implanted GaN thin films. For the AIN/GaN bi-layers, cathodoluminescence (CL) showed an increase in the intensity of the GaN band-edge peak at 3.47 eV after pulsed laser annealing at an energy density of 2000 mJ/cm2. Rutherford backscattering spectrometry of a Mg-implanted A1N (75 nm thick)/GaN (1.0 μm thick) thin-film heterostructure showed a 20% reduction of the 4He+ backscattering yield after laser annealing at an energy density of 400 mJ/cm2. CL measurements revealed a 410 nm emission peak indicating the incorporation of Mg after laser processing.

Fast-Pulse Excimer-Laser-Induced Processes in a-Si:H

1989 ◽  
Vol 164 ◽  
Author(s):  
K. Winer ◽  
R.Z. Bachrach ◽  
R.I. Johnson ◽  
S.E. Ready ◽  
G.B. Anderson ◽  
...  
Keyword(s):  
Energy Density ◽  
Excimer Laser ◽  
Impurity Concentration ◽  
Laser Annealing ◽  
Laser Energy ◽  
Laser Energy Density ◽  
Excimer Laser Annealing ◽  
Near Surface ◽  
Pulse Excimer Laser ◽  
Fast Pulse

AbstractThe effects of fast-pulse excimer laser annealing of a-Si:H were investigated by measurements of electronic transport properties and impurity concentration depth profiles as a function of incident laser energy density. The dc dark conductivity of laser-annealed, highly-doped a-Si:H increases by a factor of ∼350 above a sharp laser energy density threshold whose magnitude increases with decreasing impurity concentration and which correlates with the onset of hydrogen evolution from and crystallization of the near-surface layer. The similarities between the preparation and properties of laser-crystallized a-Si:H and pc-Si:H are discussed.

Characteristics of XeCI Excimer-Laser Annealed Insulator

1996 ◽  
Vol 424 ◽  
Author(s):  
Keun-Ho Jang ◽  
Hong-Seok Choi ◽  
Jae-Hong Jun ◽  
Jhun-Suk Yoo ◽  
Minkoo Han
Keyword(s):  
Energy Density ◽  
Metal Oxide ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Laser Energy ◽  
Breakdown Field ◽  
Oxide Interface ◽  
Annealing Effects ◽  
Silicon Structures ◽  
Tetra Ethyl Ortho Silicate

AbstractThe laser annealing effects on the TEOS (Tetra-Ethyl-Ortho-Silicate) oxide of MOS (Al/TEOS/n+ Silicon ) structures was investigated with different initial oxide conditions, such as breakdown field. The breakdown field increased upto the 170 mJ/cm2 with increasing laser energy density and decreased at 220 mJ/cm2. It is considered that the increase of breakdown field is originated from the restore of strains which exist mainly at the metal/oxide interface.

scholarly journals Fabrication and characterization of compositionally graded Bi1−x GdxFeO3 thin films

2014 ◽  
Vol 32 (3) ◽  
pp. 498-502
Author(s):  
Chang Chen ◽  
Zi Liu ◽  
Gui Wang ◽  
Xiao Feng
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Bifeo3 Thin Film ◽  
Secondary Phases ◽  
Constant Composition ◽  
Low Dissipation

AbstractAn undoped BiFeO3 thin film, Gd doped Bi0.95Gd0.05FeO3 thin film with a constant composition, Gd up-graded doped Bi1−x GdxFeO3 and Gd down-graded doped Bi1−x GdxFeO3 thin films were successfully grown on Pt (111)/Ti/SiO2/Si (100) substrates using a sol-gel and spin coating technique. The crystal structure, ferroelectric and dielectric characteristics as well as the leakage currents of these samples were thoroughly investigated. The XRD (X-Ray Diffraction) patterns indicate that all these thin films consist of solely perovskite phase with polycrystalline structure. No other secondary phases have been detected. Clear polarization-electric field (P-E) hysteresis loops of all these thin films demonstrate that the incorporation of Gd3+ into the Bi site of BFO thin film have enhanced the ferroelectric performance of pure BiFeO3 thin film, and the Gd down-graded doped Bi1−x GdxFeO3 thin film has the best ferroelectric properties. Compared to other thin films, the optimal ferroelectric behavior of the Gd down-graded doped Bi1−x GdxFeO3 thin film results from its large dielectric constant, low dissipation factor and low leakage current.

Excimer Laser Annealed Poly-Si TFT Technologies

1995 ◽  
Vol 377 ◽  
Author(s):  
Fujio Okumura ◽  
Kenji Sera ◽  
Hiroshi Tanabe ◽  
Katsuhisa Yuda ◽  
Hiroshi Okumura
Keyword(s):  
Energy Density ◽  
Leakage Current ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Laser Energy ◽  
Gate Insulator ◽  
Excimer Laser Annealing ◽  
Threshold Voltage Shift ◽  
Si Films ◽  
Current Reduction

ABSTRACTThis paper describes the excimer laser annealed (ELA) poly-Si TFT technologies in terms of excimer laser annealing of Si films, the leakage current, and the TFT stability. A laser energy density and a shot dependencies of TFT characteristics was analyzed by TEM, SEM, and Raman. The mobility increases with increasing not only the energy density but also the shot density. The mobility increase with the energy density is due to the grain size enlargement. On the other hand, the mobility increase up to 10 to 20 shots is due to a decrease of defects, including small grains, grain boundaries and defects inside grains. The contribution of grain-growth is small. The ELA TFT has a micro-offset structure to reduce the leakage current. Moreover, we have proposed a dynamic leakage current reduction structure. The combination of these technologies provides a sufficiently small leakage current for AMLCDs. The stability of the gate insulator was analyzed. The TFT shows negative threshold voltage shift under gate bias stress. This is due to water penetration and the subsequent field activated chemical reaction in the gate insulator. The dissociation of Si-OH bonds with hydrogen-bonded water was a fundamental contributor. The shift was suppressed sufficiently by hydrogen passivation. Obtained ELA TFTs;s have mobilities of over 100 cm2/Vsec, threshold voltages of less than 3 V, effective leakage currents of less than 10−13 A, and are stable more than 10 years.

Copper ohmic contacts to n-type SiC formed with pulsed excimer laser irradiation

2001 ◽  
Vol 680 ◽  
Author(s):  
K. Abe ◽  
M. Sumitomo ◽  
O. Eryu ◽  
K. Nakashima
Keyword(s):  
Energy Density ◽  
Laser Irradiation ◽  
Excimer Laser ◽  
Ohmic Contacts ◽  
Laser Energy ◽  
Contact Layer ◽  
Ohmic Behavior ◽  
Current Voltage ◽  
Excimer Laser Irradiation ◽  
Current Voltage Characteristics

ABSTRACTCopper-based ohmic contacts to n-type 6H-SiC have been investigated. In this study, ohmic contacts have been fabricated with pulsed excimer laser irradiation to Cu-deposited substrates at room temperature. It is shown that current-voltage characteristics depend on the laser energy density. Contacts formed by the laser irradiation at the energy density above 1.2 J/cm2 have shown the ohmic behavior. Cu atoms have slightly diffused into SiC by the laser irradiation at 1.4 J/cm2. As a result, a thin ohmic contact layer has been obtained by the laser processing. AES and XRD study have revealed that a Cu-SiC alloy containing Cu silicide (Cu3Si) is formed by the laser irradiation.

scholarly journals Nano-crystallization in ZnO-doped In2O3 thin films via excimer laser annealing for thin-film transistors

AIP Advances ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 065216 ◽  
Author(s):  
Mami N. Fujii ◽  
Yasuaki Ishikawa ◽  
Ryoichi Ishihara ◽  
Johan van der Cingel ◽  
Mohammad R. T. Mofrad ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Excimer Laser ◽  
Thin Film Transistors ◽  
Laser Annealing ◽  
Excimer Laser Annealing

Preparation of ATO Thin Films from SPS-Derived Large Size ATO Ceramic Targets by PVD Methods

2014 ◽  
Vol 783-786 ◽  
pp. 1973-1978
Author(s):  
Fei Chen ◽  
Jun Yan Wu ◽  
Qiang Shen ◽  
Julie M. Schoenung ◽  
Lian Meng Zhang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Properties ◽  
High Temperature ◽  
Energy Density ◽  
Laser Energy ◽  
Laser Energy Density ◽  
Electrical And Optical Properties ◽  
Large Size ◽  
Ceramic Targets

Good crystalline of ATO thin films is necessary to improve the electrical and optical properties. In this paper, ATO thin films were fabricated using PLD method at high temperature of 550 °C, and the effect of laser energy density on the microstructure, electrical property and optical property of the ATO films is discussed. The results suggest that ATO films show good crystalline when deposited at high temperature of 550 °C. Both the electrical and optical properties have been enhanced with the increasing of laser energy density. When the laser energy density is 5.4 J/cm2, the lowest resistivity of ATO thin film is obtained with the value of 6.52×10-4 Ω·cm and the average optical transmittances is 82.0 %.

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