Athermal Annealing of Silicon

1998 ◽  
Vol 510 ◽  
Author(s):  
J. Grun ◽  
C.K. Manka ◽  
C. A. Hoffman ◽  
J. R. Meyer ◽  
O. J. Glembocki ◽  
...  

AbstractWe experimentally demonstrate the annealing and electrical activation of doped silicon without the direct application of heat as in conventional thermal annealing or pulsed laser annealing. 25 × 25 × 3 mm samples of silicon doped by neutron transmutation were irradiated with a short pulse from a 1.06-micron laser. The few joule laser pulse was focused to mm-diameter surface spot which resulted in high power (∼ 1011W/cm2) capable of launching shocks into the entire sample. In a few instances the entire silicon slab, including regionsfar outside the illuminated spot, was annealed and electrically activated. In the annealed samples electrical activation of donors throughout the slab, measured with a four-point probe, was uniform and comparable to that of thermally annealed control samples. Far-infrared spectroscopy and Hall measurements also showed that the donor species was activated and Raman spectroscopy demonstrated marked improvement in the crystal structure. We conjecture that the annealing was caused by the mechanical energy that was launched into the slab by the laser pulse. Results of experiments on an ion-implanted silicon sample are also discussed.

1981 ◽  
Vol 4 ◽  
Author(s):  
A. Compaan ◽  
A. Aydinli ◽  
M. C. Lee ◽  
H. W. LO

ABSTRACTRaman measurements of temperature reported earlier have been repeated using a doubled Nd: YAG pulse for excitation and an electronically delayed dye laser pulse. These results, together with a variety of experimental tests of the Raman method, confirm the validity of the small temperature rise during pulsed laser annealing. Transmission measurements spanning the visible and near IR show that there exists a thin (∼ 70 nm) layer at the surface in which the induced absorption coefficient is ∼ 7 × 105 cm−1.


2006 ◽  
Vol 912 ◽  
Author(s):  
Toshio Joshua Kudo ◽  
Naoki Wakabayashi

AbstractIn order to form the deep PN junction demanded for the next generation IGBTs, the double-pulsed laser annealing technique as the low-thermal budget heat treatment has been introduced to activate a B-implant layer and a P-implant layer within the wafer surface to the depth 2μm. The double-pulsed laser annealing is characterized by the deep penetration depth due to a green wavelength of DPSS lasers and precisely and widely controlling of the annealing temperature and time. In the IGBT's structure the deep PN junction at a collector (the rear face) should be formed without damaging thermally circuit elements made of low melting point materials at a gate and an emitter (the front face).Ion-implant samples using eight-inch (100) Si wafers were prepared as follows: Boron (B) implant was performed at a dose of 1E+15/cm2 at an energy of 40keV and/or phosphorus (P) implant at 1E+13/cm2 at an energy of 400keV. The double-pulsed laser irradiation was carried out at the constant first and second pulse energy density E1=E2=1.8J/cm2 at the delay time td= 0-500ns and the overlap ratio OR=67-90%. The melt depth was up to about 0.3μm. The electrical activation ratio of the B-implant layer within the depth of about 0.6μm was improved from 91% to about 100% with the delay time increase of 0ns to 500ns. The activation ratio of the P-implant layer within the depth of about 2μm was drastically improved from 48% to 82% with the same delay time increase and the carriers in the P-implant layer were distributed deeply from the depth 1.1μm to 1.8μm. Furthermore, with the overlap ratio increase of 67% to 90% the carriers in the P-implant layer were distributed deeply from the depth 1.8μm to 1.9μm and the high activation ratio of 82% was maintained. The high ratio of electrical activation is supported by the defect-free epitaxial regrowth where the majority of the B dopants was diffused in the liquid phase and that of the P dopants in the solid phase.


1981 ◽  
Vol 4 ◽  
Author(s):  
R. Andrew ◽  
L. Baufay ◽  
A. Pigeolet ◽  
L.D. Laude

ABSTRACTThe preparation of AlSb thin films by pulsed laser annealing of Al/Sb sandwiches is studied in order to resolve some past controversy about the temperature rise induced by the laser pulse. Using 1000 Ȧ thick two layer films supported by TEM grids, we investigate the energy threshold for complete transformation as a function of pulse duration from 15 nsec to 100 msec, and of ambient temperature from −100°C to 250°C.We thence calculate the temperature effect directly induced by the laser to be about 930°C, or approximately the melting point of the metals, whereas inert gas furnace anneals of comparable films show transformation at this temperature occuring only in about 100 sec. We discuss the isoenergetic nature of the system for short laser pulses and the role of the heat of transformation, and thus conclude that the reaction is thermally triggered by the laser pulse but is to some extent self-sustaining via the heat of transformation locally distributed. This model is also shown to have equal validity for the systems CdTe, CdSe and AlAs.


1986 ◽  
Vol 74 ◽  
Author(s):  
A. Compaan ◽  
S. C. Abbi ◽  
H. D. Yao ◽  
A. Bhat ◽  
F. Hashmi

AbstractCarrier concentrations exceeding 1019/cm3 in GaAs implanted with Si (2 × 1014/cm2 @ 140 keV) have been obtained by pulsed laser annealing with either a dye laser (λ = 728 nm) or a XeCl excimer laser (λ = 308 nm). Carrier concentrations were measured by plasmon Raman scattering over a wide range of anneal energy densities. Compared with capless laser annealing, much higher carrier activations were achieved when the annealing laser pulse was incident through a Si3N4 cap.


1986 ◽  
Vol 74 ◽  
Author(s):  
A. Polman ◽  
S. Roorda ◽  
S. B. Ogale ◽  
F. W. Saris

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.


1980 ◽  
Vol 1 ◽  
Author(s):  
Kenji Gamo ◽  
Kouichi Murakami ◽  
Mitsuo Kawabe ◽  
Susumu Namba ◽  
Yoshinobu Aoyagi

ABSTRACTA single picosecond pulse laser annealing of ion-implanted Si is reviewed as ultra-short pulse laser annealing, comparing them with nanosecond pulse and picosecond-pulse train annealing. In order to clarify the physical mechanism of pulsed laser annealing, the dynamic behavior of the amorphous to crystalline transition has been investigated by means of time-dependent optical reflectivity measurement at 0.63 µm (cw) and 1.06 µm (30-ps pulse itself) under the irradiation of the annealing beam of a single 30-ps laser pulse at 1.06 µm. A tentative model is proposed for explaining the results and further problems which remain to be resolved are discussed.


1978 ◽  
Vol 14 (4) ◽  
pp. 85 ◽  
Author(s):  
S.S. Kular ◽  
B.J. Sealy ◽  
K.G. Stephens ◽  
D.R. Chick ◽  
Q.V. Davis ◽  
...  

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 19
Author(s):  
Sergei N. Smetanin ◽  
Michal Jelínek ◽  
Dmitry P. Tereshchenko ◽  
Mikhail N. Ershkov ◽  
Václav Kubeček

We propose and study the conditions of zero-dispersion phase matching for parametric Raman interactions in birefringent crystals differing by anisotropy of zero-dispersion wavelength and allowing for the spectral tuning of the zero-dispersion phase-matching condition. We choose a highly birefringent crystal of calcite having a wide zero-dispersion anisotropy range for the demonstration of new effects of laser pulse shortening in parametric Raman lasers with spectrally tunable zero-dispersion phase matching. We demonstrate the anti-Stokes (1168 nm) and multi-Stokes (1629 nm) picosecond pulse shortening and self-separation of single 80-ps ultra-short pulse from the zero-dispersion phase-matched parametric Raman lasers that are based on the calcite crystal without using any electro-optical device.


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