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 ◽  
...  

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.

2003 ◽  
Vol 765 ◽  
Author(s):  
G. Fortunato ◽  
L. Mariucci ◽  
V. Privitera ◽  
A. La Magna ◽  
S. Whelan ◽  
...  

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.


2001 ◽  
Vol 669 ◽  
Author(s):  
Susan Earles ◽  
Mark Law ◽  
Kevin Jones ◽  
Somit Talwar ◽  
Sean Corcoran

ABSTRACTHeavily-doped, ultra-shallow junctions in boron implanted silicon using pulsed laser annealing have been created. Laser energy in the nonmelt regime has been supplied to the silicon surface at a ramp rategreater than 1010°C/sec. This rapid ramp rate will help decrease dopant diffusion while supplying enough energy to the surface to produce dopant activation. High-dose, non-amorphizing 1 keV, 1e15 ions/cm2 boron is used. Four-point probe measurements (FPP) show a drop in sheet resistance withnonmelt laser annealing (NLA) alone. Transmission electron microscopy (TEM) shows the NLA dramatically affects the defect nucleation resulting in fewer defects with post annealing. Hall mobility and secondary ion mass spectroscopy (SIMS) results are also shown.


1995 ◽  
Vol 397 ◽  
Author(s):  
P. Boher ◽  
M. Stehle ◽  
B. Godard ◽  
J.L. Stehle

ABSTRACTPECVD amorphous silicon films deposited at different temperatures on low cost glass substrates have been treated by a Single Shot Excimer Laser Annealing (SSELA) at various energy densities. The influence of a thermal treatment at medium temperature (400°C) prior to the SSELA treatment was also investigated. Spectroscopie ellipsometry and Raman characterizations show that hydrogen contamination produces an important roughness increase with very little polycrystalline grains (650nm) after laser treatment. The thermal treatment prior laser annealing improves drastically the structural quality of the films. Structural results are correlated with the electrical performances of the TFT produced on these films.


2002 ◽  
Vol 46 (8) ◽  
pp. 1085-1090 ◽  
Author(s):  
Chang-Ho Tseng ◽  
Ching-Wei Lin ◽  
Teh-Hung Teng ◽  
Ting-Kuo Chang ◽  
Huang-Chung Cheng ◽  
...  

2013 ◽  
Vol 113 (20) ◽  
pp. 204902 ◽  
Author(s):  
G. V. Luong ◽  
S. Wirths ◽  
S. Stefanov ◽  
B. Holländer ◽  
J. Schubert ◽  
...  

1996 ◽  
pp. 376-383
Author(s):  
Pierre Boher ◽  
Jean Louis Stehle ◽  
Marc Stehle ◽  
Bruno Godard

1989 ◽  
Vol 164 ◽  
Author(s):  
K. Winer ◽  
R.Z. Bachrach ◽  
R.I. Johnson ◽  
S.E. Ready ◽  
G.B. Anderson ◽  
...  

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.


1999 ◽  
Vol 558 ◽  
Author(s):  
Mutsuko Hatano ◽  
Seungjae Moon ◽  
Minghong Lee ◽  
Kenkichi Suzuki ◽  
Costas P. Grigoropoulos

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.


2010 ◽  
Vol 09 (04) ◽  
pp. 341-344
Author(s):  
L. S. TAN ◽  
J. Y. TAN ◽  
A. BEGUM ◽  
M. H. HONG ◽  
A. Y. DU ◽  
...  

The effect of laser energy fluence and substrate heating on the annealing of boron-implanted silicon–germanium epitaxial layers on silicon was investigated. By making use of the difference in the melting points of silicon–germanium and silicon, a process window in the laser energy fluence can be found such that the meltdepth was confined within the silicon–germanium. Pre-heating of the substrate to 300°C was done to reduce the laser fluence required and improve the surface morphology. Cross-sectional transmission electron microscopy showed that there were no end-of-range defects due to ion implantation at the silicon–germanium/silicon interface after the laser annealing.


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