Threshold Energy Density for Pulsed Laser Annealing of Silicon

1980 ◽  
Vol 1 ◽  
Author(s):  
Dick Hoonhout ◽  
Frans Saris
Keyword(s):  
Energy Density ◽  
Layer Thickness ◽  
Laser Annealing ◽  
Threshold Energy ◽  
Amorphous Layer ◽  
Systematic Investigation ◽  
Laser Wavelength ◽  
Threshold Energy Density ◽  
Pulsed Laser Annealing ◽  
Disordered Layer

ABSTRACTWe have made a systematic investigation of the threshold energy density for recrystallization of ion-implanted silicon by Q-switched laser irradiation as function of thickness of the disordered layer, temperature during implantation, type and dose of implanted impurity, laser wavelength, and substrate orientation. Most results have been obtained with a Q-switched ruby laser. A linear dependence of the threshold on layer thickness (in the region of 60–300 nm) was found for arsneic-implanted silicon, but not for silicon-implanted silicon. For an amorphous layer thickness of 200 nm we found very little dependence of the threshold on type of dopant. In the case of the Nd:YAG laser, however, the lowest threshold was observed for column VI elements, the highest for column IV elements and intermediate and equal thresholds for the elements from column III and B. The influence of temperature during implantation was found to be small, but the threshold appeared to be different for (100)- and (111)- oriented substrates.

Pulsed Laser Annealing of R.F.Sputtered Amorphous Si : H.Films, Doped with Arsenic

1981 ◽  
Vol 4 ◽  
Author(s):  
E. Fogarassy ◽  
R. Stuck ◽  
M. Toulemonde ◽  
P. Siffert ◽  
J.F. Morhange ◽  
...  
Keyword(s):  
Ruby Laser ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Amorphous Layer ◽  
High Concentration ◽  
Topographic Analysis ◽  
Pulsed Laser Annealing ◽  
Residual Hydrogen ◽  
Silicon Target ◽  
Amorphous Si

Arsenic doped amorphous silicon layers have been deposited on silicon single crystals by R.F.cathodic sputtering of a silicon target in a reactive argon-hydrogen mixture, and annealed with a Q-switched Ruby laser. Topographic analysis of the irradiated layers has shown the formation of a crater, due to an evaporation effect of material which could be related to the presence of a high concentration of Ar in the amorphous layer. RBS and Raman Spectroscopy showed that the remaining layer is not recrystallised probably due to inhibition by the residual hydrogen. However, it was found that arsenic diffuses into the monocrystalline substrate by laser induced diffusion of dopant from the surface solid source, leading to the formation of good quality P-N junctions.

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.

Formation of Q-carbon by adjusting sp3 content in diamond-like carbon films and laser energy density of pulsed laser annealing

Carbon ◽  
2020 ◽  
Vol 167 ◽  
pp. 504-511 ◽  
Author(s):  
Hiroki Yoshinaka ◽  
Seiko Inubushi ◽  
Takanori Wakita ◽  
Takayoshi Yokoya ◽  
Yuji Muraoka
Keyword(s):  
Energy Density ◽  
Laser Annealing ◽  
Laser Energy ◽  
Pulsed Laser ◽  
Carbon Films ◽  
Laser Energy Density ◽  
Diamond Like Carbon ◽  
Pulsed Laser Annealing

Structural and Electronic Properties of Laser Crystallized Silicon Films

1998 ◽  
Vol 536 ◽  
Author(s):  
T. Sameshima
Keyword(s):  
Energy Density ◽  
Hall Effect ◽  
Carrier Mobility ◽  
Laser Energy ◽  
Threshold Energy ◽  
Free Carrier ◽  
Silicon Films ◽  
Laser Energy Density ◽  
Threshold Energy Density ◽  
Hall Effect Measurements

AbstractFundamental properties of silicon films crystallized by a 30-ns-pulsed XeCI excimer laser were discussed. Although crystallization of 50-nm thick silicon films formed on quartz substrates occurred through laser hearing at the crystalline threshold energy density of 160 mJ/cm2, a higher laser energy density at 360 mJ/cm2 was necessary to crystallize silicon films completely. Analyses of free carrier optical absorption revealed that phosphorus-doped silicon films with a carrier density about 2×1020 cm−3 had a high carrier mobility of 20 cm2/Vs for irradiation at the crystallization threshold energy density, while Hall effect measurements gave a carrier mobility of electrical current traversing grain boundaries of 3 cm2/Vs. This suggested that the crystalline grains had good electrical properties. As the laser energy density increased to 360 mJ/cm2 and laser pulse number increased to 5, the carrier mobility obtained by the Hall effect measurements markedly increased to 28 cm2/Vs because of improvement of grain boundary properties, while the carrier mobility obtained by analysis of free carrier absorption increased to 40 cm2/Vs. A post annealing method at 190°C with high-pressure H2O vapor was developed to reduce the density of defect states. Increase of carrier mobility to 500 cm2/Vs was demonstrated in the polycrystalline silicon thin film transistors fabricated in laser crystallized silicon films.

Light Absorption Effects on the Nd Laser Annealing of Ion Implanted Silicon

1981 ◽  
Vol 4 ◽  
Author(s):  
P. Baeri ◽  
A.E. Bapbarino ◽  
S.U. Campisano ◽  
M.G. Grimaldi ◽  
G. Foti ◽  
...  
Keyword(s):  
Energy Density ◽  
Heat Flow ◽  
Low Temperature ◽  
Laser Annealing ◽  
Amorphous Material ◽  
Amorphous Layer ◽  
Absorbed Energy ◽  
Pre Treatment ◽  
Crystallization Onset ◽  
Ion Implanted

ABSTRACTThe crystallization onset and the annealing thresholds have been nmeasured as a function of the absorbed energy density in ion implanted amorphous silicon irradiated with nanosecond Nd pulse. Thin amorphous layers (∼500 Å) require higher thresholds ccapared with thick (∼4000 Å) amorphous layers. This result can be explained in terms of balance between absorbed energy and heat flow. For a given thickness of the amorphous layer the thresholds depend on the absorption coefficient of the amorphous material. This last parameter has been varied frcm 104 to 102 CM−1 by low temperature (T<400°C) pre-treatment of the ion implanted sample. The observed drastic variations of both crystallizazion and annealing thresholds agree well with nunerical evaluation of heat flow.

Recrystallization of Amorphous Silicon Using Rapid Thermal Processing, Laser Annealing and Furnace Heating

1994 ◽  
Vol 342 ◽  
Author(s):  
J. Viatella ◽  
R.K. Singi ◽  
R.P.S. Thiakur ◽  
G. Sandhu ◽  
S.D. Harkness
Keyword(s):  
Amorphous Silicon ◽  
Laser Annealing ◽  
Laser Wavelength ◽  
X Ray Diffraction ◽  
Incoherent Light ◽  
Furnace Annealing ◽  
X Ray ◽  
Pulsed Laser Annealing ◽  
Conventional Furnace ◽  
Transmission Electron

ABSTRACTRecrystallization of amorphous silicon has been investigated using conventional furnace annealing, incoherent light-based rapid thermal annealing (RTA) and pulsed laser annealing using excimner laser (wavelength=248 nm, energy density = 0.1−0.6 J/cm2) at a pulse width of approximately 20 nanoseconds. The effects of annealing methods are characterized for grain growth and crystallized orientation using transmission electron microscopy (TEM) and X-ray diffraction analysis. The various recrystallization methods are compared based on the structural properties of the resulting film and optimized thermal budgets for each heating mechanism are discussed.

Faster Quenching by Silicon Pulsed Laser Annealing Under Water

1986 ◽  
Vol 74 ◽  
Author(s):  
A. Polman ◽  
S. Roorda ◽  
S. B. Ogale ◽  
F. W. Saris
Keyword(s):  
Laser Pulse ◽  
Laser Annealing ◽  
Crystalline Silicon ◽  
Diffusion Theory ◽  
Pulsed Laser ◽  
Silicon Layer ◽  
Water Layer ◽  
Amorphous Layer ◽  
Pulsed Laser Annealing ◽  
Novel Method

AbstractA novel method of pulsed laser processing of ion-implanted silicon is presented, in which samples are irradiated in water ambient. The water layer in contact with the silicon during irradiationh as a considerable influence on melting and solidificationd ynamics. Still, perfect epitaxy of a thin amorphous layer can be obtained using this method.For epitaxy to occur on a sample irradiated under water, 40 % more absorbed energy is necessary than for a sample irradiated in air. This indicates the occurrence of a considerable heat-flow from the silicon into the water layer during the laser pulse. From impurity redistribution after irradiation it is found that by processing a sample under water liquid-phase diffusion is reduced. Diffusion theory arguments indicate that this can be due to a reduction in total melt duration by about afactor 2–3. This can be due to faster cooling of the liquid silicon layer after the laser pulse whereas the melt-in time might be influenced as well. As a consequence, shallower impurity profiles can be obtained in crystalline silicon. No oxygen incorporation is detected and the surface morphology is not disturbed using this new process.

Sign in / Sign up

Export Citation Format

Share Document