Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Formation of C54 TiSi2: Effects of niobium additions on the apparent activation energy (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 6409-6415 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The formation of C54 TiSi2 using Ti–Nb alloys deposited on polycrystalline Si substrates was studied by means of in situ x-ray diffraction and resistance measurements during temperature ramping. Alloys with Nb contents ranging from 0 to 13.6 at. % were used. The formation temperature of C54 TiSi2 was reduced in the presence of Nb. However, the addition of Nb in Ti did not cause fundamental changes in the evolution of resistance versus temperature. This latter observation suggests that the mechanism for the formation of C54 TiSi2 remained the same in spite of the enhancement effect. For alloys with up to 8 at. % of Nb, the C49 TiSi2 phase formed first, as with pure Ti. When annealing the alloy with 13.6 at. % Nb, neither C49 TiSi2 nor C54 were found in the usual temperature ranges, instead, C40 (Nb,Ti)Si2 was observed. This phase transformed to C54 (Nb,Ti)Si2 above 950 °C. The apparent activation energy associated with the formation of C54 TiSi2 was obtained by annealing the samples at four different ramp rates from 3 to 27 K/s; it decreased continuously from 3.8 to 2.5 eV with increasing Nb content from 0 to 8 at. %. The apparent activation energy for the formation of C40 (Nb,Ti)Si2 was found to be 2.6 eV. The possible physical meaning, or lack thereof, of the high activation energies derived from experimental measurements is extensively discussed. A qualitative model is proposed whereby nucleation would be rate controlling in pure TiSi2, and interface motion in samples with 8 at. % Nb. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1413952
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Material Processing with Broad-Beam Ion Sources (1983)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Materials Research 13 (1983), S. 413-439 
    Details
    ISSN: 0084-6600
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1146/annurev.ms.13.080183.002213
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Comparison of high vacuum and ultra-high-vacuum tantalum diffusion barrier performance against copper penetration (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 300-308 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We demonstrate that depositing Ta diffusion barriers under ultra-high vacuum conditions without in situ oxygen dosing allows for variations both in microstructure and in the concentration of chemical impurities that severely degrade barrier performance. The effects of deposition pressure, in situ oxygen dosing at interfaces, hydrogen and oxygen contamination, and microstructure on diffusion barrier performance to Cu diffusion for electron-beam deposited Ta are presented. 20 nm of Ta diffusion barrier followed by a 150 nm Cu conductor were deposited under ultra-high vacuum (UHV, deposition pressure of 1×10−9 to 5 ×10−8 Torr) and high vacuum (HV, deposition pressure of 1×10−7 to 5×10−6 Torr) conditions onto 〈100〉 Si. In situ resistance furnace measurements, Auger compositional depth profiling, secondary ion mass spectrometry, and forward recoil detection along with scanning and transmission electron microscopy were used to determine the electrical, chemical, and structural changes that occurred in thin-film Ta diffusion barriers upon annealing. Undosed HV deposited Ta barriers failed from 560 to 630 °C, while undosed UHV barriers failed from 310 to 630 °C. For UHV Ta barriers, in situ oxygen dosing during deposition at the Cu/Ta interface increased the failure temperatures by 30–250 °C and decreased the range of failure temperatures to 570–630 °C. Undosed UHV Ta barriers have no systematic relationship between failure temperature and deposition pressure, although correlations between breakdown temperature, oxygen and hydrogen concentrations, and microstructural variations were measured.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353904
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    MECHANISMS FOR ENHANCED FORMATION OF THE C54 PHASE OF TITANIUM SILICIDE ULTRA-LARGE-SCALE INTEGRATION CONTACTS (2000)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Materials Research 30 (2000), S. 523-543 
    Details
    ISSN: 0084-6600
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Three methods have recently been developed to enhance the formation of the low-resistivity C54 phase of TiSi2, the most widely used silicide contact in ultra-large-scale integration devices. These methods are (a) ion implantation of a transition metal into the Si before Ti deposition; (b) deposition of a thin transition metal interlayer between the Si and Ti; and (c) codeposition of Ti alloyed with a transition metal. Each of these methods decreases the C49-to-C54 transformation temperature by 〉100oC and improves the probability of phase formation in narrow lines by increasing the nucleation site density. In this paper, we identify the aspects of phase formation that are shared by these three methods, review the methodology by which they were developed, and summarize the applications to silicon devices. Mechanisms that are responsible for the enhanced formation of C54 TiSi2 are reviewed, based on a combination of temperature-controlled in situ measurements of resistance, X-ray diffraction, and optical scattering, coupled with ex situ studies of phase formation and morphology. The main mechanisms are identified as enhanced nucleation of the C54 phase by a reduction of grain size in the C49 phase and the creation of crystallographic templates of the C40 disilicide phase and the metal-rich Ti5Si3 phase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1146/annurev.matsci.30.1.523
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Intermetallic formation in copper/magnesium thin films—kinetics, nucleation and growth, and effect of interfacial oxygen (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 5161-5170 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In situ resistance measurements, x-ray diffraction, Rutherford backscattering spectrometry, transmission electron microscopy, isothermal and constant heating rate differential scanning calorimetry and Auger electron spectrometry depth profiles have been used to investigate the interactions in copper and magnesium thin films leading to the growth of Cu2Mg and CuMg2 intermetallics. The effect of exposing the reacting interfaces to controlled exposure of oxygen on the nucleation and growth kinetics of such intermetallics was also investigated. It is found that the first phase to form is CuMg2, at about 200–215 °C. It is determined that the formation of CuMg2 occurs by a two step process consisting of nucleation and growth. The nucleation of CuMg2 takes place in a region composed of a Cu/Mg solid solution. The nuclei form at certain preferred sites and grow in directions both parallel and perpendicular to the surface, eventually leading to a continuous CuMg2 layer. The growth of CuMg2 nuclei in the plane of the original interface occurs at a constant rate, whereas the growth in a direction perpendicular to the original interface is found to be diffusion limited. In the presence of excess copper Cu2Mg forms at higher temperatures, with complete conversion to Cu2Mg occurring at about 380 °C. When the Cu surface is dosed with oxygen prior to Mg deposition, ramp rate differential scanning calorimetry (DSC) shows that the nucleation and growth of CuMg2 as well as the growth of Cu2Mg are not disturbed. Dosing the Mg surface with oxygen results in significant changes in the growth of the two phases. In this case a thin MgO layer is formed at the oxygen dosed surface, lateral growth of CuMg2 is unaffected, but vertical growth of CuMg2 across the oxygen dosed interfaces is delayed by 25–30 °C. The growth of Cu2Mg is also shown to be delayed, by 22–54 °C due to the interfacial oxygen dose.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.357231
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Control of in-plane texture of body centered cubic metal thin films (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 82 (1997), S. 4319-4326 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We show that dramatically different in-plane textures can be produced in body centered cubic (bcc) metal thin films deposited on amorphous substrates under different deposition conditions. The crystallographic orientation distribution of polycrystalline bcc metal thin films on amorphous substrates often has a strong 〈110〉 fiber texture, indicating that {110} planes are parallel to the substrate plane. When deposition takes place under bombardment by energetic ions or atoms at an off-normal angle of incidence, the 〈110〉 fiber texture develops an in-plane texture, indicating nonrandom azimuthal orientations of the crystallites. Three orientations in Nb films have been observed under different deposition geometries, in which the energetic particle flux coincides with channeling directions in the bcc crystal structure. In-plane orientations in Mo films have also been obtained in magnetron sputtering systems with various configurations. These are described, and an example is given in which the in-plane orientation of Mo films deposited in two different in-line magnetron sputtering systems differs by a 90° rotation. In these two cases, there is a strong 〈110〉 fiber texture, but the in-plane 〈100〉 direction is oriented parallel to the scan direction in one system, and perpendicular to the scan direction in the other system. The conditions which produce such different in-plane textures in two apparently similar sputtering systems are discussed. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.366239
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Kinetics of Al grain growth, Al2Cu precipitation, and dissolution in blanket thin films and fine lines (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 2781-2790 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The apparent activation energy Ea for Al grain growth, Al2Cu (aitch-theta-phase) precipitation, and Al2Cu dissolution were determined by ramped resistance measurements for both Al(Cu) blanket films and patterned lines. The Ea's measured for the initial stages of grain growth in 0.5-, 1-, and 2-μm-thick Al(4 wt % Cu), Al(2 wt % Cu), and Al films ranged from 1.19 to 1.46 eV. The Ea's for grain growth were higher for 0.6–0.9-μm-wide Al(Cu) lines than for blanket Al(Cu) films 1.89–3.1 eV, and the temperature of the peak transformation rate occurred at a much higher temperature, 310–400 vs 90–155 °C. This is due to the geometric constraints in patterned lines. The Ea's for Al2Cu precipitation in Al(4 wt % Cu) and Al(2 wt % Cu) films varied from 0.86 to 1.25 eV. For 0.6-μm-wide Al(4 wt % Cu) lines, the Ea for Al2Cu precipitation was 1.7 eV. The Ea's for Al2Cu dissolution increased with decreasing Cu content from 1.62–1.74 eV to 2.23–2.30 eV with Al(4 wt % Cu) and Al(2 wt % Cu) films, respectively. The temperature of the peak reaction rate Tp for Al2Cu dissolution increased markedly with increasing film thickness at constant ramp rates. These results demonstrate that the microstructure and Cu distribution in Al(Cu) interconnections on microelectronic chips vary as a function of feature size. This implies that blanket film data is not necessarily applicable to patterned features.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.357543
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Giant magnetoresistance of dilute Cu(Co) granular films : 38th Annual Conference on Magnetism and Magnetic Materials (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 6909-6911 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Granular films of Cu (Co) with Co concentrations from 5.4% to 12% in the as-deposited form had magnetization showing about 60% of the Co as ferromagnetic particles and exhibited giant magnetoresistance (MR) of about 20% at 4.2 K. Annealing at ∼310 °C increased the MR to 40% and also increased the saturation magnetization indicating additional Co precipitation. At higher annealing temperatures MR decreased to 1%. The Zhang theoretical model involving polarized conduction electron scattering at particle interfaces seems to give a reasonable description of our results including the quadratic behavior of MR vs [M(H)]2 and MR vs [Ms(T)]2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.356777
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The relationship between deposition conditions, the beta to alpha phase transformation, and stress relaxation in tantalum thin films (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 4918-4924 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We demonstrate that the high temperature polymorphic tantalum phase transition from the tetragonal beta phase to the cubic alpha phase causes a large decrease in the resistance of thin films and a complete stress relaxation in films that were intrinsically compressively stressed. 100 nm beta tantalum thin films with intrinsic stresses of 2.0×1010 dynes/cm2 (tensile) to −2.3×1010 dynes/cm2 (compressive) were deposited onto thermally oxidized (100) silicon wafers by evaporation or dc magnetron sputtering with argon. In situ stress and resistance at temperature were measured at 10 °C/min up to 850 °C in purified helium. Upon heating, the main stress mechanisms were elastic deformation at low temperature, plastic deformation at moderate temperatures and stress relief because of the beta-to-alpha phase transition at high temperatures. The temperature ranges over which the elastic and plastic deformation and the beta-to-alpha phase transition occurred varied with deposition pressure and substrate biasing. Incomplete compressive stress relaxation at high temperatures was observed if the film was initially deposited in the alpha phase or if the beta phase did not completely transform into alpha by 800 °C due to substrate biasing during the deposition. We conclude that the main stress relief mechanism for tantalum films with intrinsic compressive stresses to completely relax their stress is the beta-to-alpha phase transition, while for intrinsically tensile films, this transformation has a much smaller effect on the stress.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.352059
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Tantalum as a diffusion barrier between copper and silicon: Failure mechanism and effect of nitrogen additions (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 5433-5444 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The interaction of Cu with Si separated by thin (50 nm) layers of tantalum, Ta2N, and a nitrogen alloy of Ta has been investigated to determine the factors that affect the success of these materials as diffusion barriers to copper. Intermixing in these films was followed as a function of annealing temperature by in situ resistance measurements, Rutherford backscattering spectra, scanning electron microscopy, and cross-section transmission electron microscopy. Ta prevents Cu-silicon interaction up to 550 °C for 30 min in flowing purified He. At higher temperatures, copper penetration results in the formation of η‘-Cu3Si precipitates at the Ta-Si interface. Local defect sites appear on the surface of the sample in the early stages of this reaction. The Ta subsequently reacts with the substrate at 650 °C to form a planar hexagonal-TaSi2 layer. Ta silicide formation, which does not occur until 700 °C in a Ta-Si binary reaction couple, is accelerated by the presence of Cu. Nitrogen-alloyed Ta is a very similar diffusion barrier to Ta. It was found that Ta2N is a more effective barrier to copper penetration, preventing Cu reaction with the substrate for temperatures up to at least 650 °C for 30 min. In this case, local Cu-Si reaction occurs along with the formation of a uniform Ta5Si3 layer at the Ta2N-Si interface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.350566
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...