High-resolution X-ray diffraction by end of range defects in self-amorphized Ge

Bisognin, G.; Vangelista, Silvia; Bruno, E.

doi:10.1016/j.mseb.2008.08.002

Cited by 20 publications

(21 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…39 They identified these defects as interstitial-type, as confirmed by Bisognin et al with high resolution x-ray diffraction measurements. 40 The reference sample (not shown) presents after ion implantation an amorphous layer similar to that reported in Fig. 2(a) (as verified by RBS analysis) but, in contrast to the sample enriched with F, after annealing at 400 C for 1 h no defects are observed by X-TEM within the sensitivity of the technique.…”

Section: A Experimentssupporting

confidence: 67%

Fluorine effect on As diffusion in Ge

Impellizzeri

Boninelli

Priolo

et al. 2011

Journal of Applied Physics

View full text Add to dashboard Cite

The enhanced diffusion of donor atoms, via a vacancy (V)-mechanism, severely affects the realization of ultrahigh doped regions in miniaturized germanium (Ge) based devices. In this work, we report a study about the effect of fluorine (F) on the diffusion of arsenic (As) in Ge and give insights on the physical mechanisms involved. With these aims we employed experiments in Ge co-implanted with F and As and density functional theory calculations. We demonstrate that the implantation of F enriches the Ge matrix in V, causing an enhanced diffusion of As within the layer amorphized by F and As implantation and subsequently regrown by solid phase epitaxy. Next to the end-of-range damaged region F forms complexes with Ge interstitials, that act as sinks for V and induce an abrupt suppression of As diffusion. The interaction of Ge interstitials with fluorine interstitials is confirmed by theoretical calculations. Finally, we prove that a possible F-As chemical interaction does not play any significant role on dopant diffusion. These results can be applied to realize abrupt ultra-shallow n-type doped regions in future generation of Ge-based devices.

show abstract

Section: A Experimentssupporting

confidence: 67%

Fluorine effect on As diffusion in Ge

Impellizzeri

Boninelli

Priolo

et al. 2011

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…XTEM image shows the sample after the partial SPE at 300 1C for 20 h. The amorphous/crystalline interface after partial SPE is visible at $ 230 nm, while the small dot evident at $ 370 nm are the EOR defects as indicated [21]. that EOR defects induce in the Ge lattice indicates unequivocally that they are mainly formed by Is (excess atoms) [26][27][28][29][30][31][32][33][34]. Exploiting the Is-nature of the EOR defects, we want to shed light to the defects involved in B diffusion by linking the dissolution of the EOR defects with B diffusion in Ge.…”

Section: The Role Of Interstitialsmentioning

confidence: 99%

“…Finally, in all the samples we measured the chemical B profiles by SIMS, and the strain depth profiles by high resolution x-ray diffraction (HRXRD) using a Philips X'Pert PRO MRD diffractometer with the experimental setup and rocking curve simulation procedure as described in Ref. [34]. In selected samples we also performed cross-sectional TEM (XTEM) analyses with a 200 KeV Jeol 2010 Instrument.…”

Section: The Role Of Interstitialsmentioning

confidence: 99%

Role of point defects on B diffusion in Ge

Scapellato¹,

Bruno²,

Priolo³

2012

Materials Science in Semiconductor Processing

Self Cite

View full text Add to dashboard Cite

“…4,65 Typically, ion implantation in Ge hardly comes up with the formation of stable I-type defects. Only recently, it has been clarified that end-of-range (EOR) extended defects do also form in Ge after pre-amorphization followed by SPE regrowth, 111,112 even if defects are much smaller and less stable than in Si. Still, as in Si, they are made up of Is and their thermal dissolution was shown to induce TED of B.…”

Section: B Diffusion In C-ge: the Role Of Self-interstitials A Bmentioning

confidence: 99%

Mechanisms of boron diffusion in silicon and germanium

Mirabella

Salvador

Napolitani

et al. 2013

Journal of Applied Physics

Self Cite

104

View full text Add to dashboard Cite

B migration in Si and Ge matrices raised a vast attention because of its inﬂuence on the production of conﬁned, highly p-doped regions, as required by the miniaturization trend. In this scenario, the diffusion of B atoms can take place under severe conditions, often concomitant, such as very large concentration gradients, non-equilibrium point defect density, amorphous-crystalline transition, extrinsic doping level, co-doping, B clusters formation and dissolution, ultra-short high-temperature annealing. In this paper, we review a large amount of experimental work and present our current understanding of the B diffusion mechanism, disentangling concomitant effects and describing the underlying physics. Whatever the matrix, B migration in amorphous (a-) or crystalline (c-) Si, or c-Ge is revealed to be an indirect process, activated by point defects of the hosting medium. In a-Si in the 450-650 C range, B diffusivity is 5 orders of magnitude higher than in c-Si, with a transient longer than the typical amorphous relaxation time. A quick B precipitation is also evidenced for concentrations larger than 2 x10^20 B/cm3. B migration in a-Si occurs with the creation of a metastable mobile B, jumping between adjacent sites, stimulated by dangling bonds of a-Si whose density is enhanced by B itself (larger B density causes higher B diffusivity). Similar activation energies for migration of B atoms (3.0 eV) and of dangling bonds (2.6 eV) have been extracted. In c-Si, B diffusion is largely affected by the Fermi level position, occurring through the interaction between the negatively charged substitutional B and a self-interstitial (I) in the neutral or doubly positively charged state, if under intrinsic or extrinsic (p-type doping) conditions, respectively. After charge exchanges, the migrating, uncharged BI pair is formed. Under high n-type doping conditions, B diffusion occurs also through the negatively charged BI pair, even if the migration is depressed by Coulomb pairing with n-type dopants. The interplay between B clustering and migration is also modeled, since B diffusion is greatly affected by precipitation. Small (below 1 nm) and relatively large (5-10 nm in size) BI clusters have been identiﬁed with different energy barriers for thermal dissolution (3.6 or 4.8 eV, respectively). In c-Ge, B motion is by far less evident than in c-Si, even if the migration mechanism is revealed to be similarly assisted by Is. If Is density is increased well above the equilibrium (as during ion irradiation), B diffusion occurs up to quite large extents and also at relatively low temperatures, disclosing the underlying mechanism. The lower B diffusivity and the larger activation barrier (4.65 eV, rather than 3.45 eV in c-Si) can be explained by the intrinsic shortage of Is in Ge and by their large formation energy. B diffusion can be strongly enhanced with a proper point defect engineering, as achieved with embedded GeO2 nanoclusters, causing at 650 °C a large Is supersaturation. These aspects of B diffusion are presented and discus...

show abstract

High-resolution X-ray diffraction by end of range defects in self-amorphized Ge

Cited by 20 publications

References 22 publications

Fluorine effect on As diffusion in Ge

Fluorine effect on As diffusion in Ge

Role of point defects on B diffusion in Ge

Mechanisms of boron diffusion in silicon and germanium

Contact Info

Product

Resources

About