Implanted B and P dopants in Si exhibit transient enhanced diffusion (TED) during annealing which arises from the excess interstitials generated by the implant. In order to study the mechanisms of TED, transmission electron microscopy measurements of implantation damage were combined with B diffusion experiments using doping marker structures grown by molecular-beam epitaxy (MBE). Damage from nonamorphizing Si implants at doses ranging from 5×1012 to 1×1014/cm2 evolves into a distribution of {311} interstitial agglomerates during the initial annealing stages at 670–815 °C. The excess interstitial concentration contained in these defects roughly equals the implanted ion dose, an observation that is corroborated by atomistic Monte Carlo simulations of implantation and annealing processes. The injection of interstitials from the damage region involves the dissolution of {311} defects during Ostwald ripening with an activation energy of 3.8±0.2 eV. The excess interstitials drive substitutional B into electric...

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Physical mechanisms of transient enhanced dopant diffusion in ion-implanted silicon

High temperature oxidation behavior and research status of modifications on improving high temperature oxidation resistance of titanium alloys and titanium aluminides: A review

Si nanoclusters embedded in SiO2 have been produced by thermal annealing of SiOx films prepared by plasma enhanced chemical vapor deposition. The structural properties of the system have been investigated by energy filtered transmission electron microscopy (EFTEM). EFTEM has evidenced the presence of a relevant contribution of amorphous nanostructures, not detectable by using the more conventional dark field transmission electron microscopy technique. By also taking into account this contribution, an accurate quantitative description of the evolution of the samples upon thermal annealing has been accomplished. In particular, the temperatures at which the nucleation of amorphous and crystalline Si nanoclusters starts have been determined. Furthermore, the nanocluster mean radius and density have been determined as a function of the annealing temperature. Finally, the optical and the structural properties of the system have been compared, to demonstrate that the photoluminescence properties of the system depend on both the amorphous and crystalline clusters.

Formation and evolution of luminescent Si nanoclusters produced by thermal annealing of SiOx films

In this paper, optoelectronic characteristics and related switching behavior of one monolithically integrated silicon light-emitting device (LED) with an interesting wavelength range of 400–900 nm are studied. Through the comparison of two types of geometry, Si avalanche-based LED and Si field-effect LED (Si FE LED), in the same device, we establish the dimensional dependence of the switching speed of the LED. Almost-linear modulation curve implies lower distortion is shown for the Si FE LED with light emission enhancement, and technology computer aided design (TCAD) simulations are in line with the experimental results. Our findings indicate that ON–OFF keying up to GHz frequencies should be feasible with such diodes. Potential applications should include Si FE LED integrated into the micro-photonic systems.

https://robots.iopscience.iop.org/article/10.1088/1361-6439/abf333/pdf

Silicon electro-optic micro-modulator fabricated in standard CMOS technology as components for all silicon monolithic integrated optoelectronic systems *

The atomic process, kinetics, and equilibrium thermodynamics underlying the gettering of transition-metal impurities in Si are reviewed. Methods for mathematical modeling of gettering are discussed and illustrated. Needs for further research are considered.

https://digital.library.unt.edu/ark:/67531/metadc702553/m2/1/high_res_d/753385.pdf

Mechanisms of transition-metal gettering in silicon

The photoluminescence (PL) and electroluminescence (EL) properties of Ge-implanted SiO2 layers thermally grown on a Si substrate were investigated and compared to those of Si-implanted SiO2 films. The PL spectra from Ge-implanted SiO2 were recorded as a function of annealing temperature. It was found that the blue-violet PL from Ge-rich oxide layers reaches a maximum after annealing at 500 °C for 30 min, and is substantially more intense than the PL emission from Si-implanted oxides. The neutral oxygen vacancy is believed to be responsible for the observed luminescence. The EL spectrum from the Ge-implanted oxide after annealing at 1000 °C correlates very well with the PL one, and shows a linear dependence on the injected current. The EL emission was strong enough to be readily seen with the naked eye and the EL efficiency was assessed to be about 5×10−4.

Strong blue and violet photoluminescence and electroluminescence from germanium-implanted and silicon-implanted silicon-dioxide layers

Experiments are reported which explore the possibility of using low‐temperature, multiple‐energy Si+ ion implantation into thin SiO2 films on Si and subsequent short‐time thermal processing to form silicon nanostructures capable of yielding a high‐intensity emission in the short‐wavelength part of the visible spectrum. A room‐temperature short‐wavelength PL band of high intensity was found after double implantation with energies of 200 and 100 keV at a temperature of −20 °C to a total dose of 4.8×10 16 cm−2 (atomic concentration about 2×1021 cm−3) and subsequent furnace annealing at 400 °C for 0.5 h in forming gas or by flash lamp annealing at 1050 °C for 20 ms.

Room‐temperature, short‐wavelength (400–500 nm) photoluminescence from silicon‐implanted silicon dioxide films

The use of flash lamp annealing for ultrashallow junction formation in silicon has been described. Low energy boron and arsenic implants have been heat-treated in this way using peak temperatures in the range of 1100 to 1300°C and effective anneal times of 20 and 3 ms. Secondary ion mass spectrometry and four-point probe measurements have been undertaken to determine the junction depth and the sheet resistance, respectively. Optimum processing conditions have been identified, under which one can obtain combinations of junction depth and sheet resistance values that meet the 90 nm technology node requirements and beyond.

Advanced Thermal Processing of Ultrashallow Implanted Junctions Using Flash Lamp Annealing

The formation of helium induced cavities in silicon is studied as a function of implant energy (10 and 40 keV) and dose (1×1015, 1×1016, and 5×1016 cm−2). Specimens are analyzed after annealing (800 °C, 10 min) by transmission electron microscopy (TEM) and elastic recoil detection (ERD). Cavity nucleation and growth phenomena are discussed in terms of three different regimes depending on the implanted He content. For the low (1×1015 cm−2) and high (5×1016 cm−2) doses our results are consistent with the information in the literature. However, at the medium dose (1×1016 cm−2), contrary to the gas release calculations which predict the formation of empty cavities, ERD analysis shows that a measurable fraction of the implanted He is still present in the annealed samples. In this case TEM analyses reveal that the cavities are surrounded by a strong strain field contrast and dislocation loops are generated. The results obtained are discussed on the basis of an alternative nucleation and growth behavior that all...

Overpressurized bubbles versus voids formed in helium implanted and annealed silicon

Thermally-grown, 500 nm thick SiO 2 films were implanted with 1.6 × 10 16 –1.6 × 10 17 cm −2 Si + ions at 100 and 200 keV. Then the samples were subjected to either rapid thermal annealing at 900–1200°C for 1s or flash-lamp annealing at 1050–1350°C for 20 ms. Photoluminescence (PL) measurements, Raman spectroscopy (RS) and high-resolution transmission electron microscopy (HREM) were employed for sample characterization. Weak room-temperature (RT) visible PL was observed before the transient anneals. RS revealed in these samples a broad band centered at 480 cm −1 indicating the presence of non-crystalline Si inclusions. The initial annealing steps decreased the PL intensity, but after 1200°C, 1 s or 1350°C, 20 ms the PL was found to increase considerably over the red and IR region with a maximum around 830 nm. Simultaneously, the Raman signal at 480 cm −1 diminished and additional scattering near 520 cm −1 arose pointing to the formation of Si nanocrystals. Formation of 2–6 nm Si nanocrystals was directly confirmed by HREM. It is difficult to explain their occurrence by diffusion-limited growth or solid-phase crystallization of α-Si phase inclusions, if any. A model is presented considering the Si nanocrystal formation via segregation of Si atoms from SiO x , rapid percolation-like formation of Si chains or fractals and finally their transformation to Si phase inclusions and nanocrystals. The dramatic increase in PL correlated with the Si nanocrystals formation is considered to support the idea of quantum-confined origin of PL.

Rossen Yankov

Papers

Strong blue and violet photoluminescence and electroluminescence from germanium-implanted and silicon-implanted silicon-dioxide layers

Room‐temperature, short‐wavelength (400–500 nm) photoluminescence from silicon‐implanted silicon dioxide films

Advanced Thermal Processing of Ultrashallow Implanted Junctions Using Flash Lamp Annealing

Overpressurized bubbles versus voids formed in helium implanted and annealed silicon

Visible and near-infrared luminescence from silicon nanostructures formed by ion implantation and pulse annealing