The Luminescent Properties of Ion-Implantation-Fabricated SiO2:nc-Si Nanostructures Annealed at High Temperatures

2003 ◽  
Vol 777 ◽  
Author(s):  
David I. Tetelbaum ◽  
Oleg N. Gorshkov ◽  
Alexandr P. Kasatkin ◽  
Vladimir A. Burdov ◽  
Sergey A. Trushin ◽  
...  

AbstractThe influence of the Si+ implantation dose and postimplantation annealing temperature on the photoluminescence (PL) intensity of silicon nanoinclusions in an SiO2 matrix was experimentally investigated. The way that the PL varied with dose and annealing temperature was explained on the basis of a model which takes into account the Ostwald ripening of nanocrystals and effect of the quantum dot size on the rate of radiative recombination.

2000 ◽  
Vol 647 ◽  
Author(s):  
K.-H. Heinig ◽  
B. Schmidt ◽  
M. Strobel ◽  
H. Bernas

AbstractUnder ion irradiation collisional mixing competes with phase separation if the irradiated solid consists of immiscible components. If a component is a chemical compound, there is another competition between the collisional forced chemical dissociation of the compound and its thermally activated re-formation. Especially at interfaces between immiscible components, irradiation processes far from thermodynamical equilibrium may lead to new phenomena. If the formation of nanoclusters (NCs) occurs during ion implantation, the phase separation caused by ion implantation induced supersaturation can be superimposed by phenomena caused by collisional mixing. In this contribution it will be studied how collisional mixing during high-fluence ion implantation affects NC synthesis and how ion irradiation through a layer of NCs modifies their size and size distribution. Inverse Ostwald ripening of NCs will be predicted theoretically and by kinetic lattice Monte-Carlo simulations. The mathematical treatment of the competition between irradiation-induced detachment of atoms from clusters and their thermally activated diffusion leads to a Gibbs-Thomson relation with modified parameters. The predictions have been confirmed by experimental studies of the evolution of Au NCs in SiO2 irradiated by MeV ions. The unusual behavior results from an effective negative capillary length, which will be shown to be the reason for inverse Ostwald ripening. Another new phenomenon to be addressed is self-organization of NCs in a d-layer parallel to the Si/SiO2 interface. Such d-layers were found when the damage level at the interface was of the order of 1-3 dpa. It will be discussed that the origin of the d-layer of NCs can be assigned to two different mechanisms: (i) The negative interface energy due to collisional mixing gives rise to the formation of tiny clusters of substrate material in front of the interface, which promotes heteronucleation of the implanted impurities. (ii) Collisional mixing in the SiO2produces diffusing oxygen, which may be consumed by the Si/SiO2 interface. A thin layer parallel to the interface becomes denuded of diffusing oxygen, which results in a strong pile up of Si excess. This Si excess promotes heteronucleation too. Independent of the dominating mechanism of self-organization of a d-layer of NCs, its location in SiO2 close to the SiO2/Si interface makes it interesting for non-volatile memory application.


1988 ◽  
Vol 100 ◽  
Author(s):  
D. B. Poker ◽  
D. K. Thomas

ABSTRACTIon implantation of Ti into LINbO3 has been shown to be an effective means of producing optical waveguides, while maintaining better control over the resulting concentration profile of the dopant than can be achieved by in-diffusion. While undoped, amorphous LiNbO3 can be regrown by solid-phase epitaxy at 400°C with a regrowth velocity of 250 Å/min, the higher concentrations of Ti required to form a waveguide (∼10%) slow the regrowth considerably, so that temperatures approaching 800°C are used. Complete removal of residual damage requires annealing temperatures of 1000°C, not significantly lower than those used with in-diffusion. Solid phase epitaxy of Agimplanted LiNbO3, however, occurs at much lower temperatures. The regrowth is completed at 400°C, and annealing of all residual damage occurs at or below 800°C. Furthermore, the regrowth rate is independent of Ag concentration up to the highest dose implanted to date, 1 × 1017 Ag/cm2. The usefulness of Ag implantation for the formation of optical waveguides is limited, however, by the higher mobility of Ag at the annealing temperature, compared to Ti.


1981 ◽  
Vol 7 ◽  
Author(s):  
B.S. Elman ◽  
H. Mazurek ◽  
M.S. Dresselhaus ◽  
G. Dresselhaus

ABSTRACTRaman spectroscopy is used in a variety of ways to monitor different aspects of the lattice damage caused by ion implantation into graphite. Particular attention is given to the use of Raman spectroscopy to monitor the restoration of lattice order by the annealing process, which depends critically on the annealing temperature and on the extent of the original lattice damage. At low fluences the highly disordered region is localized in the implanted region and relatively low annealing temperatures are required, compared with the implantation at high fluences where the highly disordered region extends all the way to the surface. At high fluences, annealing temperatures comparable to those required for the graphitization of carbons are necessary to fully restore lattice order.


2006 ◽  
Vol 27 (4) ◽  
pp. 205-207 ◽  
Author(s):  
F. Recht ◽  
L. McCarthy ◽  
S. Rajan ◽  
A. Chakraborty ◽  
C. Poblenz ◽  
...  

2002 ◽  
Vol 716 ◽  
Author(s):  
Takaaki Amada ◽  
Nobuhide Maeda ◽  
Kentaro Shibahara

AbstractAn Mo gate work function control technique which uses annealing or N+ ion implantation has been reported by Ranade et al. We have fabricated Mo-gate MOS diodes, based on their report, with 5-20 nm SiO2 and found that the gate leakage current was increased as the N+ implantation dose and implantation energy were increased. Although a work function shift was observed in the C-V characteristics, a hump caused by high-density interface states was found for high-dose specimens. Nevertheless, a work function shift larger than -1V was achieved. However, nitrogen concentration at the Si surface was about 1x1020 cm-3 for the specimen with a large work function shift.


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