Effect of Nitrogen Implants on Boron Transient Enhanced Diffusion

2000 ◽  
Vol 610 ◽  
Author(s):  
Omer Dokumaci ◽  
Paul Ronsheim ◽  
Suri Hegde ◽  
Dureseti Chidambarrao ◽  
Lahir Shaik-Adam ◽  
...  

AbstractThe effect of nitrogen implants on boron transient enhanced diffusion was studied for nitrogen-only, boron-only, and boron plus nitrogen implants. A boron buried layer was used as a detector for interstitial supersaturation in the samples. Boron dose ranged from 1×1014 to 1×1015 cm−2 and N2+ dose from 5×1013 and 5×1014 cm−2. The energies were chosen such that the location of the nitrogen and boron peaks matched. After the implants, RTA and low temperature furnace anneals were carried out. The diffusivity enhancements were extracted from the buried layer profiles by simulation. Nitrogen-only implants were found to cause significant enhanced diffusion on the buried boron layer. For lower doses, the enhancement of the nitrogen implant is about half as that of boron whereas the enhancements are equal at higher doses. Nitrogen coimplant with boron increases the transient enhanced diffusion of boron at low boron doses, which implies that nitrogen does not act as a strong sink for excess interstitials unlike carbon. At high boron doses, nitrogen co-implant does not significantly change boron diffusion. Sheet resistance measurements indicate that low nitrogen doses do not affect the activation of boron whereas high nitrogen doses either reduce the activation of boron or the mobility of the holes.

1986 ◽  
Vol 74 ◽  
Author(s):  
R. Angelucci ◽  
E. Gabilli ◽  
R. Lotti ◽  
P. Negrini ◽  
M. Servidori ◽  
...  

AbstractTransient enhanced diffusion is observed for P, As and Sb as a consequence of the recovery of the damage created by a silicon dose below the amorphization threshold. The phenomenon results more pronounced for low temperature furnace heating than after rapid thermal annealing and for those elements having a larger component of interstitialcy diffusion mechanism.A close correlation was found between the trends of the anomalous dopant diffusion and the implant damage evolution analyzed by X-ray diffraction. This evolution takes place via interstitial cluster dissolution.


2004 ◽  
Vol 810 ◽  
Author(s):  
A. Halimaoui ◽  
J. M. Hartmann ◽  
C. Laviron ◽  
R. El-Farhane ◽  
F. Laugier

ABSTRACTPreviously published articles have shown that co-implanted fluorine reduces transient enhanced diffusion of boron. However, it is not yet elucidated whether this effect is due to interaction of fluorine with point-defects or boron atoms. In this work, we have used boron redistribution in a shallow Delta-doped Si structures in order to get some insights into the role of fluorine in the boron diffusion. The structures consisted of 3 boron-doped layers separated by 40nm-thick undoped silicon. The samples were given to Ge preamorphization and F co-implant. SIMS depth profiling was used to analyse boron redistribution after annealing. The results we obtained strongly suggest that fluorine is not interacting with point-defects. The reduction in boron TED is most probably due to boron-fluorine interaction.


2004 ◽  
Vol 810 ◽  
Author(s):  
Huda A. W. A. El Mubarek ◽  
Yun Wang ◽  
Janet M. Bonar ◽  
Peter Hemment ◽  
Peter Ashburn

ABSTRACTThis paper investigates the effect of varying F+ implantation energy on boron thermal diffusion and boron transient enhanced diffusion (TED) in metastable Si0.86Ge0.14 by characterising the diffusion of a boron marker layer in samples with and without P+ and F+ implants. The effect of two F+ implantation energies (185keV and 42keV) was studied at two anneal temperatures 950°C and 1025°C. In samples implanted with P+ & 185keV F+, the fluorine suppresses boron transient enhanced diffusion completely at 950°C and suppresses thermal diffusion by 25% at 1025°C. In samples implanted with P+ & 42keV F+, the fluorine does not reduce boron transient enhanced diffusion at 950°C. This result is explained by the location of the boron marker layer in the vacancy-rich region of the fluorine damage profile for the 185keV implant but in the interstitial-rich region for the 42keV implant. Isolated dislocation loops are seen in the SiGe layer for the 185keV implant. We postulate that these loops are due to the partial relaxation of the metastable Si0.86Ge0.14 layer.


1997 ◽  
Vol 490 ◽  
Author(s):  
Noriyuki Sugiyasu ◽  
Kaina Suzuki ◽  
Syuichi Kojima ◽  
Yasushi Ohyama

ABSTRACTWe have proposed a coupled and de-coupled combined method to solve partial differential equations for a transient enhanced diffusion model. In the case of a boron diffusion process, the sum of concentrations of interstitial Si and of impurity-interstitial pair, the sum of concentrations of vacancy and of impurity-vacancy pair and each chemical impurity concentration are kept constant. The charge neutrality law is also applied. This procedure has realized a robust solution system which is implemented into our in-house FEM-based 2-D process simulator, and transient enhanced diffusion simulations for a sub-quarter micron nMOSFET have been demonstrated.


1996 ◽  
Vol 438 ◽  
Author(s):  
M. E. Law ◽  
K. S. Jones ◽  
S. K. Earles ◽  
A. D. Lilak ◽  
J-W. Xu

AbstractTransient Enhanced Diffusion (TED) is one of the biggest modeling challenges present in predicting scaled technologies. Damage from implantation of dopant ions changes the diffusivities of the dopants and precipitates to form complex extended defects. Developing a quantitative model for the extended defect behavior during short time, low temperature anneals is a key to explaining TED. This paper reviews some of the modeling developments over the last several years, and discusses some of the challenges that remain to be addressed. Two examples of models compared to experimental work are presented and discussed.


1996 ◽  
Vol 439 ◽  
Author(s):  
S. Solmi ◽  
S. Valmorri

AbstractA simulation model for Boron diffusion which takes into account the aggregation of the excess interstitials in clusters, and subsequently, the dissolution of these defects, is proposed. The interstitial supersaturation and generation rate are determined according to the classical theory of nucleation and growth of particles, in analogy with the precipitation of a new phase in heavily doped silicon. The clusters are considered as precipitates formed by interstitial Si atoms. The B diffusion is modelled on the basis of the dopant-interstitial pair diffusion mechanism. The clusters dissolution during annealing maintains nearly constant, for a long period, the interstitial supersaturation and the related enhancement of the boron diffusion. This gives a good account of the diffusion results over a large range of experimental conditions. Furthermore, this approach describes most of the behavior of the transient enhanced diffusion (TED), like the temperature dependence of the level of the B diffusion enhancement, the dependence of the duration of the phenomenon on implanted dose, and the scarce dependence on the damage distribution in depth. The results of the simulations are compared with experimental data on the kinetics of interstitial cluster dissolution and of B TED.


2005 ◽  
Vol 864 ◽  
Author(s):  
F. Cayrel ◽  
D. Alquier ◽  
C. Dubois ◽  
R. Jerisian

AbstractHigh dose helium implantation followed by a suitable thermal treatment induces defects such as cavities and dislocations. Gettering efficiency of this technique for metallic impurities has been widely proved. Nevertheless, dopants, as well as point defects, interact with this defect layer. Due to the presence of vacancy type defects after helium implantation, boron diffusion can be largely influenced by such a buried layer. In this paper, we study the influence of helium induced defects on boron diffusion. The boron diffusion in presence of these defects has been analyzed as a function of different parameters such as distance between boron profile and defect layer and defect density. Our results demonstrate that the major impact known as boron enhanced diffusion can be partially or completely suppressed depending on parameters of experiments. Moreover, these results clarify the interaction of boron with extended He-induced defects.


1999 ◽  
Vol 568 ◽  
Author(s):  
Kenji Taniguchi ◽  
Tomoya Saito ◽  
Jianxin Xia ◽  
Ryangsu Kim ◽  
Takenori Aoki ◽  
...  

ABSTRACTBoron segregation to {311} defects and transient enhanced diffusion (TED) of boron atoms during thermal annealing were investigated in detail using implanted superlattice and Si bulk wafers. We observed that (1)boron atoms segregate to {311} defects during low temperature annealing, (2){311} defects were formed in the area where the self-interstitial concentration exceeds 3×1017cm3, (3)free self-interstitials in the region beyond the implanted range causes initial rapid enhanced diffusion prior to the onset of normal TED.


Sign in / Sign up

Export Citation Format

Share Document