Ultra-Shallow Junction Formation by Excimer Laser Annealing of Ultra-Low Energy B Implanted in Si

2003 ◽  
Vol 765 ◽  
Author(s):  
G. Fortunato ◽  
L. Mariucci ◽  
V. Privitera ◽  
A. La Magna ◽  
S. Whelan ◽  
...  
Keyword(s):  
Excimer Laser ◽  
Laser Annealing ◽  
Laser Energy ◽  
Laser Pulses ◽  
Low Energy ◽  
Excimer Laser Annealing ◽  
High Resolution Tem ◽  
Ultra Shallow Junctions ◽  
Dopant Redistribution ◽  
Melt Duration

AbstractFormation of ultra-shallow junctions by excimer laser annealing (ELA) of ultra-low energy (1keV –250 eV) B implanted in Si has been investigated. High resolution TEM has been used to assess the as-implanted damage and the crystal recovery following ELA. The electrical activation and redistribution of B in Si during ELA has been studied as a function of the laser energy density (melt depth), the implant dose and the number of laser pulses (melt duration). Under appropriate ELA conditions, ultra-shallow profiles, extending to a depth as low as 35 nm with an abrupt profile (2.5 nm/dec), have been achieved. A significant amount of the implanted dopant was lost from the sample following ELA. However, the dopant that was retained in crystal material was fully activated following rapid re-solidification. We developed a theoretical model, that considers the dopant redistribution during melting and regrowth, showing that the fraction of the implanted dopant not activated during ELA was lost from the sample through out diffusion. The lateral distribution of the implanted B following laser annealing has been studied with 2-D measurements, using selective etching and cross-section TEM on samples where the implanted dopant was confined by using test structures including windows opened in silicon dioxide masks and patterned gate stack structures.

Single-Shot Excimer Laser Annealing and In Process Ellipsometry Analysis for Ultra Shallow Junctions

2002 ◽  
Vol 717 ◽  
Author(s):  
T. Noguchi ◽  
G. Kerrien ◽  
T. Sarnet ◽  
D. Débarre ◽  
J. Boulmer ◽  
...  
Keyword(s):  
Excimer Laser ◽  
Spectroscopic Ellipsometry ◽  
Laser Annealing ◽  
Laser Energy ◽  
Process Analysis ◽  
Single Shot ◽  
Excimer Laser Annealing ◽  
Dopant Activation ◽  
The Difference ◽  
Ultra Shallow Junctions

AbstractSingle-shot Excimer Laser Annealing (ELA) was performed onto Si surface that was previously B+ implanted with or without Ge+ pre-amorphization. As a result, p+ type USJ (Ultra-Shallow Junction) has been formed. In process analysis, using Infrared Spectroscopic Ellipsometry (IR-SE) has been performed and compared with conventional 4-point probe method. Also, the corresponding crystallinity for the USJ of Si surface has been studied using Ultraviolet-Visible (UV-Vis) Spectroscopic Ellipsometry. In the case of pre-amorphization by Ge+ implantation, the laser energy density threshold required for melting the surface, and therefore for electrical activation, decreased drastically because of the difference in the thermodynamic properties of the amorphized Si. Estimation of the junction depth shows a shallower junction when using UV-SE, as compared to IR-SE. This can be explained by the fact that, in the UV range, the crystallinity of the top layer is predominant while IR-SE is more sensitive to dopant activation. This efficient single-shot ELA is a candidate for the USJ formation for sub-0.1 νm CMOS transistors. The effective method for investigating the activation state related to the crystallinity by using UV-SE and IR-SE is expected to apply as a non-contact analytical tool for USJ formation.

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.

Effect of excimer laser annealing on the structural properties of silicon germanium films

2004 ◽  
Vol 19 (12) ◽  
pp. 3503-3511 ◽  
Author(s):  
Sherif Sedky ◽  
Jeremy Schroeder ◽  
Timothy Sands ◽  
Tsu-Jae King ◽  
Roger T. Howe
Keyword(s):  
Surface Roughness ◽  
Excimer Laser ◽  
Silicon Germanium ◽  
Laser Annealing ◽  
Chemical Vapor ◽  
Laser Pulses ◽  
Film Structure ◽  
Excimer Laser Annealing ◽  
Pressure Chemical ◽  
Columnar Grain

We investigated the use of a pulsed excimer laser having a wavelength of 248 nm, a pulse duration of 38 ns, and an average fluence between 120 and 780 mJ/cm2 to locally tailor the physical properties of Si1−xGex (18% < x < 90%) films deposited by low-pressure chemical vapor deposition at temperatures between 400 and 450 °C. Amorphous as-deposited films showed, after laser annealing, strong {111} texture, a columnar grain microstructure, and an average resistivity of 0.7 mΩ cm. Atomic force microscopy indicated that the first few laser pulses resulted in a noticeable reduction in surface roughness, proportional to the pulse energy. However, a large number of successive pulses dramatically increased the surface roughness. The maximum thermal penetration depth of the laser pulse is demonstrated to depend on the fluence and the film structure being either polycrystalline or amorphous. Finally, a comparison between excimer laser annealing and metal-induced crystallization and rapid thermal annealing is presented.

Melting and resolidification dynamics of a-Si and poly-Si thin films during excimer laser annealing

1999 ◽  
Vol 558 ◽  
Author(s):  
Mutsuko Hatano ◽  
Seungjae Moon ◽  
Minghong Lee ◽  
Kenkichi Suzuki ◽  
Costas P. Grigoropoulos
Keyword(s):  
Excimer Laser ◽  
Laser Annealing ◽  
Laser Energy ◽  
Electrical Conductance ◽  
Temperature History ◽  
Maximum Temperature ◽  
Excimer Laser Annealing ◽  
Complete Melting ◽  
In Situ Experiments ◽  
Melting Regime

ABSTRACTThe liquid-solid interface motion and the temperature history of thin Si films during excimer laser annealing are observed by in-situ experiments combining time-resolved (∼Ins) electrical conductance, optical reflectance/transmittance at visible and near-IR wavelength, and thermal emission measurements. The existence of partial and complete melting regimes is elucidated. In the partial melting regime, the maximum temperature remains close to the melting point of aSi, since the laser energy is consumed on the latent heat of phase-change. In the complete melting regime, substantial supercooling, followed by homogeneous nucleation is observed. These phase transformations are consistent with the recrystallized poly-Si morphologies.

Pulsed Excimer Laser (308 nm) Annealing Of Ion Implanted Silicon and Solar Cell Fabrication

1982 ◽  
Vol 13 ◽  
Author(s):  
D. H. Lowndes ◽  
J. W. Cleland ◽  
W. H Christie ◽  
R. E EBY ◽  
G. E. Jellison ◽  
...  
Keyword(s):  
Excimer Laser ◽  
Laser Annealing ◽  
Surface Damage ◽  
Laser Pulses ◽  
Open Circuit ◽  
Electrical Measurements ◽  
Large Area ◽  
Model Calculations ◽  
Substrate Heating ◽  
Dopant Redistribution

ABSTRACTA pulsed ultraviolet excimer laser (XeCl, 308 nm wavelength, 40 nsec FWHM pulse duration) has been successfully used for laser annealing of both boron- and arsenic-implanted silicon. TEM, SIMS, and sheet electrical measurements are used to characterize specimens. C-V and I-V measurements demonstrate that near-ideal p-n junctions are formed (diode perfection factor A = 1.2). Electrical activation of implanted ions by single laser pulses is essentially complete for energy densities Eℓ≥ 1.4 J/cm2 , far below the threshold for substantial surface damage ∽4.5 J/cm2. Melting model calculations are in good agreement with observed thresholds for dopant redistribution and for epitaxial regrowth. Changes in annealing behavior resulting from multiple (1,2,5) laser pulses are also reported. Finally, we demonstrate the use of scanned overlapping excimer laser pulses for fabrication of large area (2 cm2 ) solar cells with good performance characteristics. In contrast to pulsed ruby laser annealing, high open circuit voltages can be obtained without the use of substrate heating.

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.

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