Investigation of Fluorine Effect on the Boron Diffusion by Mean of Boron Redistribution in Shallow Delta-doped Layers

2004 ◽  
Vol 810 ◽  
Author(s):  
A. Halimaoui ◽  
J. M. Hartmann ◽  
C. Laviron ◽  
R. El-Farhane ◽  
F. Laugier
Keyword(s):  
Point Defects ◽  
Depth Profiling ◽  
Boron Diffusion ◽  
Enhanced Diffusion ◽  
Boron Doped ◽  
Transient Enhanced Diffusion ◽  
Sims Depth Profiling

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.

The Role of Surface Annihilation in Annealing Investigated by Atomic Model Simulation

2005 ◽  
Vol 864 ◽  
Author(s):  
Min Yu ◽  
Xiao Zhang ◽  
Ru Huang ◽  
Xing Zhang ◽  
Yangyuan Wang ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Integrated Circuits ◽  
Point Defects ◽  
Model Simulation ◽  
Kinetic Monte Carlo ◽  
Boron Diffusion ◽  
Junction Depth ◽  
Kinetic Monte Carlo Method ◽  
Enhanced Diffusion

AbstractBehavior of point defects in annealing is investigated a lot in order to suppress the Transient Enhanced Diffusion (TED) of boron as is urged by the development of integrated circuits. Surface annihilation possibility for point defects is very important in determining junction depth in the case of ultra-shallow doping. However the understanding on it is still ambiguous considering the inconsistent results on surface annihilation behavior. In this paper the variation of surface annihilation possibility is studied. The simulation on boron diffusion as well as silicon diffusion is performed. The evolution of Si clusters is simulated. By explaining experimental results with Kinetic Monte Carlo method based simulation, we proposed that surface annihilation possibility varies in different cases.

The Role of Vacancies and Interstitials in Transient Enhanced Diffusion of Arsenic Implanted into Silicon

1997 ◽  
Vol 469 ◽  
Author(s):  
D. Venables ◽  
V. Krishnamoorthy ◽  
H.- J. Gossmann ◽  
A. Lilak ◽  
K. S. Jones ◽  
...  
Keyword(s):  
Fermi Level ◽  
Point Defect ◽  
Boron Diffusion ◽  
Direct Role ◽  
Enhanced Diffusion ◽  
Projected Range ◽  
Transient Enhanced Diffusion ◽  
Diffusion Enhancement ◽  
Recombination Centers

ABSTRACTBoron and antimony doped superlattices (DSLs) were implanted with arsenic at 40 keV to doses of 2×1014 cm−2, 5×1015 cm−2 and 2×1016 cm−2. Increasing the arsenic dose above 5×1015 cm−2 resulted in a reduction in the extent of arsenic transient enhanced diffusion (TED) following annealing at 700°C, 16 hr. Concurrent with this reduction in TED was a reduction in the number of free interstitials beyond the end-of-range, as measured by the boron diffusion enhancement in the doped superlattices. No enhancement in antimony diffusivity was observed in this region, indicating that vacancies play no direct role in the diffusion of arsenic in this region, although an indirect role for vacancies as recombination centers for mobile interstitials is not precluded by these experiments. We conclude that interstitials dominate arsenic diffusion in the end-of-range region and beyond. Interpretation of the DSL data in the projected range region is complicated by Fermi level and segregation effects and no definitive conclusion can be reached about the point defect populations in this region.

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 ◽  
...  
Keyword(s):  
Low Temperature ◽  
Boron Diffusion ◽  
High Nitrogen ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
High Boron ◽  
Buried Layer ◽  
Higher Doses ◽  
Low Nitrogen ◽  
Temperature Furnace

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.

The Effect of Fluorine Implantation on Boron Diffusion in Metastable Si0.86 Ge0.14

2004 ◽  
Vol 810 ◽  
Author(s):  
Huda A. W. A. El Mubarek ◽  
Yun Wang ◽  
Janet M. Bonar ◽  
Peter Hemment ◽  
Peter Ashburn
Keyword(s):  
Thermal Diffusion ◽  
Sige Layer ◽  
Dislocation Loops ◽  
Boron Diffusion ◽  
Rich Region ◽  
Implantation Energy ◽  
Enhanced Diffusion ◽  
Partial Relaxation ◽  
Transient Enhanced Diffusion ◽  
Marker Layer

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.

A New Practical Approach to Implement a Transient Enhanced Diffusion Model into an Fem-Based 2-D Process Simulator

1997 ◽  
Vol 490 ◽  
Author(s):  
Noriyuki Sugiyasu ◽  
Kaina Suzuki ◽  
Syuichi Kojima ◽  
Yasushi Ohyama
Keyword(s):  
Diffusion Model ◽  
Boron Diffusion ◽  
Combined Method ◽  
Solution System ◽  
Charge Neutrality ◽  
Robust Solution ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Vacancy Pair ◽  
Process Simulator

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.

The Influence of Amorphizing Implants on Boron Diffusion in Silicon

1997 ◽  
Vol 469 ◽  
Author(s):  
H. S. Chao ◽  
P. B. Griffin ◽  
J. D. Plummer
Keyword(s):  
Point Defects ◽  
Field Enhancement ◽  
Enhancement Effect ◽  
Dislocation Loops ◽  
Boron Diffusion ◽  
Electric Field Enhancement ◽  
Diffusion Behavior ◽  
Enhanced Diffusion ◽  
Pile Up ◽  
Experimental Structure

ABSTRACTThe transient enhanced diffusion behavior of B after ion implantation above the amorphization threshold is investigated. The experimental structure uses a layer of epitaxially grown Si, uniformly doped with B to act as a diffusion monitor. Wafers using this structure are implanted with amorphizing doses of Si, As, or P and annealed for various times at various temperatures. The experimental results show that upon annealing after Si implantation, there is a large amount of B pile-up that occurs at the amorphous/crystalline (A/C) interface while B is depleted from the region just beyond the A/C interface. This pile-up/depletion phenomenon can be attributed to the dislocation loops that form at the A/C interface. These loops act as sinks for interstitial point defects. There is also B pile-up/depletion behavior for As and P implants as well. However, this behavior may be explained by an electric field enhancement effect. While dislocation loops are known to form at the A/C interface for all of the investigated implant conditions, it appears that while they are necessary to simulate for Si amorphizing implants, they may not be necessary to simulate for As and P amorphizing implants.

Transient Enhanced Diffusion of Boron in Silicon:The Interstitial Flux

1996 ◽  
Vol 439 ◽  
Author(s):  
T. W. Simpson ◽  
R. D. Goldberg ◽  
I. V. Mitchell ◽  
J.-M. Baribeau
Keyword(s):  
Annealing Stage ◽  
Enhanced Diffusion ◽  
Boron Doped ◽  
Transient Enhanced Diffusion ◽  
The Relationship

AbstractDelta-doped boron marker layers in silicon have been used to test further the relationship between B transient enhanced diffusion (TED) and the flux of silicon interstitials released during the annealing stage following self implantation. We present new data which address a number of questions raised by the present models. We show that in our experiments bulk trapping of interstitials is significant only for low implant fluences (˜1012 cm2). The origin of the observed diffusion-like profiles for the interstitial flux is instead found to lie in local trapping within the δ-doped layers themselves. Boron trapped in immobile clusters may be associated with Si interstitials in approximately a 1:1 ratio; nevertheless this trapping contribution alone may not entirely account for the observed gradient. We suggest that some part of the observed TED response with depth is attributable to local trapping of silicon interstitials within the boron doped layers.

Local Density Diffusivity (LDD-) Model for Boron Out-Diffusion of In Situ Boron-Doped Si0.75Ge0.25 Epitaxial Films Post Advanced Rapid Thermal Anneals with Carbon Co-Implant

2010 ◽  
Vol 307 ◽  
pp. 63-73
Author(s):  
Frank Wirbeleit
Keyword(s):  
Silicon Germanium ◽  
Local Density ◽  
Diffusion Control ◽  
Boron Diffusion ◽  
Enhanced Diffusion ◽  
Boron Doped ◽  
Model Slope ◽  
Post Implantation ◽  
Device Technology

Boron in silicon has presented challenges for decades because of clustering and so-called transient enhanced diffusion [1-2]. An understanding of boron diffusion post rapid thermal annealing in general, and out of in situ doped epitaxially grown silicon-germanium films in particular, is essential to hetero junction engineering in microelectronic device technology today. In order to model boron diffusion, post-implantation, the local density diffusion (LDD) model has been applied in the past [3]. Via mathematical convolution of the diffusion model slope and the initial boron concentration profile, these former results were transferred to this work. In this way, non-diffusing boron was predicted to exist in the center of the presented in situ boron-doped films. In addition, boron diffusion control by co-implanted carbon was demonstrated and the applied LDD model was completed and confirmed by adapting A. Einstein’s proof [4] for this purpose.

Dislocations Induced by Heavy Boron Doping of Silicon

1991 ◽  
Vol 49 ◽  
pp. 814-815
Author(s):  
X. J. Ning ◽  
P. Pirouz
Keyword(s):  
Mechanical Properties ◽  
Critical Role ◽  
Boron Doping ◽  
Boron Diffusion ◽  
Boron Doped ◽  
Chemical Etch ◽  
Etch Stop

Diffusion-induced dislocations in silicon have long been of interest in semiconducting devices. Several investigations concerning the dislocations induced by doping of Si were carried out during the early sixties. However, there are still a number of unresolved questions concerning this problem. Because the boron doped chemical etch-stop technique is widely used in the fabrication of microsensors, new interest has arisen in the role of dislocations induced by boron diffusion and the behavior of these dislocations on the mechanical properties of microsensors. The doping of Si in this technique is heavy (>5x1019cm-3) and, consequently, the density of induced dislocations in the wafer is large. The dislocations will probably then play a critical role on the mechanical properties of thin Si wafers used in the etch-stop technique.

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