... R.Carboni, G.Pacchioni, M.Fanciulli, A.Giglia, M.Pedio, N.Mahne, S.Nannarone, and F.Boscherin... more ... R.Carboni, G.Pacchioni, M.Fanciulli, A.Giglia, M.Pedio, N.Mahne, S.Nannarone, and F.Boscherini, Coordination of boron and phosphorous in ... J.Zhu, TDdella Rubia, LHYang, and C.Mailhiot, Ab initio pseudopotential calculations of B diffusion and pairing in Si, Phys. Rev. ...
A study of doping the pMOS Lightly Doped Drain (LDD) by Plasma Immersion Ion Implantation (P3i) w... more A study of doping the pMOS Lightly Doped Drain (LDD) by Plasma Immersion Ion Implantation (P3i) with BF3 is presented which demonstrates a better transistor performance compared to standard beam line Ion Implantation (I∕I). The benefit of P3i comes from the broad ...
One of the important challenges to the semiconductor industry today is to enhance the solid solub... more One of the important challenges to the semiconductor industry today is to enhance the solid solubility of several dopants, boron in particular, in silicon. We calculate the equilibrium solid solubility of boron in Si from first principles and examine the effect of biaxial stress. We find an unexpectedly large enhancement, on the order of 150%, for only 1% strain primarily due to the charge of the substitutional boron impurity in Si. We point out that this effect is an intrinsic property of Si and is expected to be important for other dopants as well.
A method for enhancing the equilibrium solubility of boron and indium in silicon. The method invo... more A method for enhancing the equilibrium solubility of boron and indium in silicon. The method involves first-principles quantum mechanical calculations to determine the temperature dependence of the equilibrium solubility of two important p-type dopants in silicon, namely boron and indium, under various strain conditions. The equilibrium thermodynamic solubility of size-mismatched impurities, such as boron and indium in silicon, can be
An exhaustive first-principles study of the energetics of B-Si interstitial complexes of various ... more An exhaustive first-principles study of the energetics of B-Si interstitial complexes of various configurations and charge states is used to elucidate the diffusion mechanism of B in Si. Total energy calculations and molecular dynamics simulations show that B diffuses by an interstitialcy mechanism. ...
A method for enhancing the equilibrium solubility of boron ad indium in silicon. The method invol... more A method for enhancing the equilibrium solubility of boron ad indium in silicon. The method involves first-principles quantum mechanical calculations to determine the temperature dependence of the equilibrium solubility of two important p-type dopants in silicon, namely boron and indium, under various strain conditions. The equilibrium thermodynamic solubility of size-mismatched impurities, such as boron and indium in silicon, can be
Journal of Stroke & Cerebrovascular Diseases, 1996
An ultra high vacuum, low energy ion implanter was used in conjunction with a range of analytical... more An ultra high vacuum, low energy ion implanter was used in conjunction with a range of analytical techniques to study the range and damage distributions of B+ ions implanted at normal incidence into Si(100) samples held at room temperature. Samples were implanted over a dose range from 1E14 ions/cm2 with and without a surface oxide layer and those implanted at 1 keV and below were capped with a nominal 20 nm layer of 28Si by ion beam deposition in situ in order to produce an oxygen equilibration layer for subsequent secondary ion mass spectrometry depth profiling. The samples were analysed using secondary ion mass spectroscopy, medium energy ion scattering, spectroscopic ellipsometry, spreading resistance profiling and high resolution, cross section transmission electron microscopy to obtain the range and damage distributions and junction depths. The general observations were that channelling occurs at all energies studied, and that the relationship between the damage and range dist...
Ultra-Shallow Junctions for the 65 nm Node Based on Defect and Stress Engineering. Victor Moroz, ... more Ultra-Shallow Junctions for the 65 nm Node Based on Defect and Stress Engineering. Victor Moroz, Majeed Foad, Houda Graoui, Faran Nouri, Dipu Pramanik, Susan Felch Semiconductor Defect Engineering--Materials, Synthetic Structures and Devices 864, 113-118, 3/2005. ...
SCS 2003 International Symposium on Signals Circuits and Systems Proceedings (Cat No 03EX720) IIT-02, 2002
There has been increasing interest in using Indium (In+) as the channel and substrate dopant in p... more There has been increasing interest in using Indium (In+) as the channel and substrate dopant in place of the lighter boron atom. Indium is a heavier atom and hence yields a more controllable and steeper dopant profile, which is extremely important to reduce short channel effects (SCE) in modem MOSFETs. Studies have been done on using In as the channel dopant and devices with improved SCE have been reported. In+ has also been studied as a halo implant species to enhance the short channel performance of devices. However, indium shows enhanced diffusivity in the presence of some source of interstitials. To this effect, work has been done to study the diffusion of In in silicon under neutral and oxidizing ambients. In this paper, we study and present experimental results on the indium diffusion behavior and dose loss as a function of different damage structures and anneal conditions, utilizing low energy electron induced X-ray emission spectrometry (LEXES) and secondary ion mass spectro...
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 2000
The formation of P ϩ /N shallow junctions for 0.18 m technology requires the incorporation of dop... more The formation of P ϩ /N shallow junctions for 0.18 m technology requires the incorporation of dopant atoms, e.g., boron, at a depth of 540Ϯ180 Å below the surface of the crystal. This is done by implanting boron ions at low energies. Another approach for forming shallow junctions involves, in principle, implanting large molecular ions accelerated to higher energies but with an equivalent low energy per boron atom. Decaborane was implanted at 4 and 7 keV and doses of 1E13 and 1E14 cm Ϫ2. Junctions with depth Ͻ600 Å and sheet resistance of 480 ⍀/ᮀ have been demonstrated. Annealed samples were also examined using high-resolution cross-section transmission electron microscopy. Molecular ion implantation of Si using decaborane has been simulated using molecular dynamics at energies between 4 and 1 keV per molecule. The simulation shows local swelling resulting from individual molecular impact, and hydrogen is also implanted into silicon.
1998 International Conference on Ion Implantation Technology. Proceedings (Cat. No.98EX144)
The effects of ion energy, accumulated dose, photoresist coverage and patterning were studied for... more The effects of ion energy, accumulated dose, photoresist coverage and patterning were studied for As + implants at 40, 60 and 120 keV and total doses from 1x10 14 to 10 16 As/cm 2. The effect of photoresist coverage, ion energy and dose on positive and negative potentials and j-V characteristics are presented. J-V data are fit with a beam plasma model that describes both positive and negative charging with a consistent set of plasma parameters.
Reducing channeling of B implants and transient enhanced diffusion (TED) is very critical for the... more Reducing channeling of B implants and transient enhanced diffusion (TED) is very critical for the formation of ultra shallow junctions required for deep sub-micron devices. As the ion energy required for junction formation is reduced (<5 keV) due to device shrinking, the use of high tilt angle (typically 7-10 deg) becomes ineffective in suppressing channeling. The formation of a thin
International Electron Devices Meeting. IEDM Technical Digest
Figure 2.(a) A PROPHET simulation of a Lg =150nm nMOSFET illustrating the intended junction profi... more Figure 2.(a) A PROPHET simulation of a Lg =150nm nMOSFET illustrating the intended junction profile. (b) An SCM micrograph revealing the doping profilein the corresponding device fab-ricated as described in the text. The device was biased at -0.5V relative to the tip. The ...
2009 International Workshop on Junction Technology, 2009
In this work, studies carried out with several techniques on As junctions activated by solid phas... more In this work, studies carried out with several techniques on As junctions activated by solid phase epitaxial regrowth (SPER), rapid thermal process (RTP) spike annealing and laser sub-melt annealing (LA) are summarized. In particular, the sheet resistance (Rs) values and Hall effect measured active carrier doses are interpreted after investigation by secondary ion mass spectrometry (SIMS) and extended x-ray absorption
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms, 2006
In order to meet the technological requirements for the next generations of p-n junctions, highly... more In order to meet the technological requirements for the next generations of p-n junctions, highly promising methods consist of B and C ultra-low energy co-implantation in Ge pre-amorphized Si. We investigated the B diffusion and the activation phenomena occurring during post-annealing of ultra-shallow junctions (USJ) obtained by spike annealing Si samples pre-amorphized by 20 keV Ge and coimplanted with C at 4 keV and B at 500 eV. Isochronal (60 s) post-annealing processes were performed in inert atmosphere (N 2) by rapid thermal annealing (RTA) in the 500-1050°C temperature range. We show that, contrary to what reported in the literature about C-free USJ, no B diffusion occurs up to 900°C, and further B clustering is completely suppressed over the whole investigated temperature range. Moreover we observed an increase of the sheet resistance by increasing the temperature up to 900°C followed by a subsequent decrease, that can be easily interpreted on the basis of B diffusion and segregation in native SiO 2 and B cluster dissolution. Finally, we show that C significantly reduces up to two orders of magnitude the diffusion coefficient of B, that in our experiments is present in highly extrinsic conditions.
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 2008
ABSTRACT The authors have investigated ultrashallow p+ /n-junction formation by solid-phase epita... more ABSTRACT The authors have investigated ultrashallow p+ /n-junction formation by solid-phase epitaxy, by using x-ray absorption near-edge spectroscopy �XANES� measurements at the B K edge. The authors demonstrate that B clustering occurs during the very early stages of annealing-induced Si recrystallization, i.e., when B is still in the amorphous matrix. After complete regrowth, the local structure around B remains the same as in the amorphous phase, implying that B clusters are transferred to the crystalline structure. The XANES structure are assigned to B–B sp2 bonds that are present in B clusters with two or more B atoms. Boron clustering and diffusion are further investigated by means of concentration profile analysis of ad hoc amorphous on insulator structures that evidences a clear concentration threshold for clustering and a concentration dependent B diffusion.
This patent is Subject to a terminal dis-A method for enhancing the equilibrium solubility of bor... more This patent is Subject to a terminal dis-A method for enhancing the equilibrium solubility of boron claimer. and indium in Silicon. The method involves first-principles quantum mechanical calculations to determine the tempera (21) Appl. No.: 10/246,890 ture dependence of the equilibrium solubility of two impor tant p-type dopants in Silicon, namely boron and indium, (22) Filed: Sep. 18, 2002 under various Strain conditions. The equilibrium thermody O O namic solubility of size-mismatched impurities, such as (65) Prior Publication Data boron and indium in Silicon, can be raised significantly if the US 2003/0032268 A1 Feb. 13, 2003 Silicon Substrate is Strained appropriately. For example, for boron, a 1% compressive Strain raises the equilibrium Solu Related U.S. Application Data bility by 100% at 1100° C.; and for indium, a 1% tensile strain at 1100 C., corresponds to an enhancement of the (63) Continuation of application No. 09/945,932, filed on Sep. 4, solubility by 200%.
International Electron Devices Meeting. IEDM Technical Digest, 1997
Monte Carlo simulations of 0.25-2 keV B implantations are shown to agree well with molecular dyna... more Monte Carlo simulations of 0.25-2 keV B implantations are shown to agree well with molecular dynamics simulations and SIMS data. The tails of point responses and dopant distributions at mask edges are found to be dominated by (1 10) channeling and to have only a slight dependence on tilt angle. A 3-D analytical model is proposed which approximates the Monte Carlo distributions well.
... R.Carboni, G.Pacchioni, M.Fanciulli, A.Giglia, M.Pedio, N.Mahne, S.Nannarone, and F.Boscherin... more ... R.Carboni, G.Pacchioni, M.Fanciulli, A.Giglia, M.Pedio, N.Mahne, S.Nannarone, and F.Boscherini, Coordination of boron and phosphorous in ... J.Zhu, TDdella Rubia, LHYang, and C.Mailhiot, Ab initio pseudopotential calculations of B diffusion and pairing in Si, Phys. Rev. ...
A study of doping the pMOS Lightly Doped Drain (LDD) by Plasma Immersion Ion Implantation (P3i) w... more A study of doping the pMOS Lightly Doped Drain (LDD) by Plasma Immersion Ion Implantation (P3i) with BF3 is presented which demonstrates a better transistor performance compared to standard beam line Ion Implantation (I∕I). The benefit of P3i comes from the broad ...
One of the important challenges to the semiconductor industry today is to enhance the solid solub... more One of the important challenges to the semiconductor industry today is to enhance the solid solubility of several dopants, boron in particular, in silicon. We calculate the equilibrium solid solubility of boron in Si from first principles and examine the effect of biaxial stress. We find an unexpectedly large enhancement, on the order of 150%, for only 1% strain primarily due to the charge of the substitutional boron impurity in Si. We point out that this effect is an intrinsic property of Si and is expected to be important for other dopants as well.
A method for enhancing the equilibrium solubility of boron and indium in silicon. The method invo... more A method for enhancing the equilibrium solubility of boron and indium in silicon. The method involves first-principles quantum mechanical calculations to determine the temperature dependence of the equilibrium solubility of two important p-type dopants in silicon, namely boron and indium, under various strain conditions. The equilibrium thermodynamic solubility of size-mismatched impurities, such as boron and indium in silicon, can be
An exhaustive first-principles study of the energetics of B-Si interstitial complexes of various ... more An exhaustive first-principles study of the energetics of B-Si interstitial complexes of various configurations and charge states is used to elucidate the diffusion mechanism of B in Si. Total energy calculations and molecular dynamics simulations show that B diffuses by an interstitialcy mechanism. ...
A method for enhancing the equilibrium solubility of boron ad indium in silicon. The method invol... more A method for enhancing the equilibrium solubility of boron ad indium in silicon. The method involves first-principles quantum mechanical calculations to determine the temperature dependence of the equilibrium solubility of two important p-type dopants in silicon, namely boron and indium, under various strain conditions. The equilibrium thermodynamic solubility of size-mismatched impurities, such as boron and indium in silicon, can be
Journal of Stroke & Cerebrovascular Diseases, 1996
An ultra high vacuum, low energy ion implanter was used in conjunction with a range of analytical... more An ultra high vacuum, low energy ion implanter was used in conjunction with a range of analytical techniques to study the range and damage distributions of B+ ions implanted at normal incidence into Si(100) samples held at room temperature. Samples were implanted over a dose range from 1E14 ions/cm2 with and without a surface oxide layer and those implanted at 1 keV and below were capped with a nominal 20 nm layer of 28Si by ion beam deposition in situ in order to produce an oxygen equilibration layer for subsequent secondary ion mass spectrometry depth profiling. The samples were analysed using secondary ion mass spectroscopy, medium energy ion scattering, spectroscopic ellipsometry, spreading resistance profiling and high resolution, cross section transmission electron microscopy to obtain the range and damage distributions and junction depths. The general observations were that channelling occurs at all energies studied, and that the relationship between the damage and range dist...
Ultra-Shallow Junctions for the 65 nm Node Based on Defect and Stress Engineering. Victor Moroz, ... more Ultra-Shallow Junctions for the 65 nm Node Based on Defect and Stress Engineering. Victor Moroz, Majeed Foad, Houda Graoui, Faran Nouri, Dipu Pramanik, Susan Felch Semiconductor Defect Engineering--Materials, Synthetic Structures and Devices 864, 113-118, 3/2005. ...
SCS 2003 International Symposium on Signals Circuits and Systems Proceedings (Cat No 03EX720) IIT-02, 2002
There has been increasing interest in using Indium (In+) as the channel and substrate dopant in p... more There has been increasing interest in using Indium (In+) as the channel and substrate dopant in place of the lighter boron atom. Indium is a heavier atom and hence yields a more controllable and steeper dopant profile, which is extremely important to reduce short channel effects (SCE) in modem MOSFETs. Studies have been done on using In as the channel dopant and devices with improved SCE have been reported. In+ has also been studied as a halo implant species to enhance the short channel performance of devices. However, indium shows enhanced diffusivity in the presence of some source of interstitials. To this effect, work has been done to study the diffusion of In in silicon under neutral and oxidizing ambients. In this paper, we study and present experimental results on the indium diffusion behavior and dose loss as a function of different damage structures and anneal conditions, utilizing low energy electron induced X-ray emission spectrometry (LEXES) and secondary ion mass spectro...
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 2000
The formation of P ϩ /N shallow junctions for 0.18 m technology requires the incorporation of dop... more The formation of P ϩ /N shallow junctions for 0.18 m technology requires the incorporation of dopant atoms, e.g., boron, at a depth of 540Ϯ180 Å below the surface of the crystal. This is done by implanting boron ions at low energies. Another approach for forming shallow junctions involves, in principle, implanting large molecular ions accelerated to higher energies but with an equivalent low energy per boron atom. Decaborane was implanted at 4 and 7 keV and doses of 1E13 and 1E14 cm Ϫ2. Junctions with depth Ͻ600 Å and sheet resistance of 480 ⍀/ᮀ have been demonstrated. Annealed samples were also examined using high-resolution cross-section transmission electron microscopy. Molecular ion implantation of Si using decaborane has been simulated using molecular dynamics at energies between 4 and 1 keV per molecule. The simulation shows local swelling resulting from individual molecular impact, and hydrogen is also implanted into silicon.
1998 International Conference on Ion Implantation Technology. Proceedings (Cat. No.98EX144)
The effects of ion energy, accumulated dose, photoresist coverage and patterning were studied for... more The effects of ion energy, accumulated dose, photoresist coverage and patterning were studied for As + implants at 40, 60 and 120 keV and total doses from 1x10 14 to 10 16 As/cm 2. The effect of photoresist coverage, ion energy and dose on positive and negative potentials and j-V characteristics are presented. J-V data are fit with a beam plasma model that describes both positive and negative charging with a consistent set of plasma parameters.
Reducing channeling of B implants and transient enhanced diffusion (TED) is very critical for the... more Reducing channeling of B implants and transient enhanced diffusion (TED) is very critical for the formation of ultra shallow junctions required for deep sub-micron devices. As the ion energy required for junction formation is reduced (<5 keV) due to device shrinking, the use of high tilt angle (typically 7-10 deg) becomes ineffective in suppressing channeling. The formation of a thin
International Electron Devices Meeting. IEDM Technical Digest
Figure 2.(a) A PROPHET simulation of a Lg =150nm nMOSFET illustrating the intended junction profi... more Figure 2.(a) A PROPHET simulation of a Lg =150nm nMOSFET illustrating the intended junction profile. (b) An SCM micrograph revealing the doping profilein the corresponding device fab-ricated as described in the text. The device was biased at -0.5V relative to the tip. The ...
2009 International Workshop on Junction Technology, 2009
In this work, studies carried out with several techniques on As junctions activated by solid phas... more In this work, studies carried out with several techniques on As junctions activated by solid phase epitaxial regrowth (SPER), rapid thermal process (RTP) spike annealing and laser sub-melt annealing (LA) are summarized. In particular, the sheet resistance (Rs) values and Hall effect measured active carrier doses are interpreted after investigation by secondary ion mass spectrometry (SIMS) and extended x-ray absorption
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms, 2006
In order to meet the technological requirements for the next generations of p-n junctions, highly... more In order to meet the technological requirements for the next generations of p-n junctions, highly promising methods consist of B and C ultra-low energy co-implantation in Ge pre-amorphized Si. We investigated the B diffusion and the activation phenomena occurring during post-annealing of ultra-shallow junctions (USJ) obtained by spike annealing Si samples pre-amorphized by 20 keV Ge and coimplanted with C at 4 keV and B at 500 eV. Isochronal (60 s) post-annealing processes were performed in inert atmosphere (N 2) by rapid thermal annealing (RTA) in the 500-1050°C temperature range. We show that, contrary to what reported in the literature about C-free USJ, no B diffusion occurs up to 900°C, and further B clustering is completely suppressed over the whole investigated temperature range. Moreover we observed an increase of the sheet resistance by increasing the temperature up to 900°C followed by a subsequent decrease, that can be easily interpreted on the basis of B diffusion and segregation in native SiO 2 and B cluster dissolution. Finally, we show that C significantly reduces up to two orders of magnitude the diffusion coefficient of B, that in our experiments is present in highly extrinsic conditions.
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 2008
ABSTRACT The authors have investigated ultrashallow p+ /n-junction formation by solid-phase epita... more ABSTRACT The authors have investigated ultrashallow p+ /n-junction formation by solid-phase epitaxy, by using x-ray absorption near-edge spectroscopy �XANES� measurements at the B K edge. The authors demonstrate that B clustering occurs during the very early stages of annealing-induced Si recrystallization, i.e., when B is still in the amorphous matrix. After complete regrowth, the local structure around B remains the same as in the amorphous phase, implying that B clusters are transferred to the crystalline structure. The XANES structure are assigned to B–B sp2 bonds that are present in B clusters with two or more B atoms. Boron clustering and diffusion are further investigated by means of concentration profile analysis of ad hoc amorphous on insulator structures that evidences a clear concentration threshold for clustering and a concentration dependent B diffusion.
This patent is Subject to a terminal dis-A method for enhancing the equilibrium solubility of bor... more This patent is Subject to a terminal dis-A method for enhancing the equilibrium solubility of boron claimer. and indium in Silicon. The method involves first-principles quantum mechanical calculations to determine the tempera (21) Appl. No.: 10/246,890 ture dependence of the equilibrium solubility of two impor tant p-type dopants in Silicon, namely boron and indium, (22) Filed: Sep. 18, 2002 under various Strain conditions. The equilibrium thermody O O namic solubility of size-mismatched impurities, such as (65) Prior Publication Data boron and indium in Silicon, can be raised significantly if the US 2003/0032268 A1 Feb. 13, 2003 Silicon Substrate is Strained appropriately. For example, for boron, a 1% compressive Strain raises the equilibrium Solu Related U.S. Application Data bility by 100% at 1100° C.; and for indium, a 1% tensile strain at 1100 C., corresponds to an enhancement of the (63) Continuation of application No. 09/945,932, filed on Sep. 4, solubility by 200%.
International Electron Devices Meeting. IEDM Technical Digest, 1997
Monte Carlo simulations of 0.25-2 keV B implantations are shown to agree well with molecular dyna... more Monte Carlo simulations of 0.25-2 keV B implantations are shown to agree well with molecular dynamics simulations and SIMS data. The tails of point responses and dopant distributions at mask edges are found to be dominated by (1 10) channeling and to have only a slight dependence on tilt angle. A 3-D analytical model is proposed which approximates the Monte Carlo distributions well.
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