摘要 :
We investigate the crystallization of amorphous Ge alloy layers on silicon substrates for optical and electronic applications. Amorphous GeSn layers are obtained by limiting the adatom surface mobility during deposition. Subsequen...
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We investigate the crystallization of amorphous Ge alloy layers on silicon substrates for optical and electronic applications. Amorphous GeSn layers are obtained by limiting the adatom surface mobility during deposition. Subsequent annealing transforms the amorphous layer into single-crystalline GeSn by solid phase epitaxy. Structural investigation shows excellent structural quality for layers with up to 6.1% Sn. The surface and interface are smooth thanks to the low thermal budget. The GeSn layers show a significant increase in optical absorption with respect to Ge. We demonstrate tensile-strained GeSn p-type pMOSFET devices on Si(111) substrates using solid phase epitaxy of amorphous GeSn layer, with 4.5% Sn and +0.33% tensile strain. Structural investigation showed the presence of twin defects in the GeSn layers after crystallization. In this work we present a method to effectively suppress the formation of twin defects. Furthermore we demonstrate the crystallization of multiple amorphous layers in a 1 step anneal.
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摘要 :
We investigate the crystallization of amorphous Ge alloy layers on silicon substrates for optical and electronic applications. Amorphous GeSn layers are obtained by limiting the adatom surface mobility during deposition. Subsequen...
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We investigate the crystallization of amorphous Ge alloy layers on silicon substrates for optical and electronic applications. Amorphous GeSn layers are obtained by limiting the adatom surface mobility during deposition. Subsequent annealing transforms the amorphous layer into single-crystalline GeSn by solid phase epitaxy. Structural investigation shows excellent structural quality for layers with up to 6.1% Sn. The surface and interface are smooth thanks to the low thermal budget. The GeSn layers show a significant increase in optical absorption with respect to Ge. We demonstrate tensile-strained GeSn p-type pMOSFET devices on Si(111) substrates using solid phase epitaxy of amorphous GeSn layer, with 4.5% Sn and +0.33% tensile strain. Structural investigation showed the presence of twin defects in the GeSn layers after crystallization. In this work we present a method to effectively suppress the formation of twin defects. Furthermore we demonstrate the crystallization of multiple amorphous layers in a 1 step anneal.
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Reduction of electrical resistance of middle-of-line (MOL) is now a primary requirement for advanced CMOS. In this paper, we demonstrate that the cluster-preforming-deposited (CPD) WSi_n (n ≤ 12) film is a promising contact mater...
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Reduction of electrical resistance of middle-of-line (MOL) is now a primary requirement for advanced CMOS. In this paper, we demonstrate that the cluster-preforming-deposited (CPD) WSi_n (n ≤ 12) film is a promising contact material for S/D in CMOS; insertion of the WSi_n film reduces the electron SBH to 0.32 eV at W/n-Si and to 0.43 eV at Co/n-Si junctions. This SBH reduction is due to the fact that the WSi_n film has a low work function of 4.0 eV and effectively passivates the Si surface without forming an appreciable density of interface states, thereby releasing the Fermi level pinning at the Si surface. These junctions have an excellent stability against annealing up to 700℃ for W/WSi_n/n-Si and to 500℃ for Co/WSi_n/n-Si. Furthermore, this film significantly prevents the Cu diffusion with a TDDB barrier height of 1.33 eV under a 5 MV/cm stress.
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We present the ionization of decaborane (B_(10)H_(14)) and formation of hydrogen- and boron-contents-controlled B_(10-y)H_x~+ through the charge transfer from ambient gas ion to decaborane molecules in an external quadrupole stati...
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We present the ionization of decaborane (B_(10)H_(14)) and formation of hydrogen- and boron-contents-controlled B_(10-y)H_x~+ through the charge transfer from ambient gas ion to decaborane molecules in an external quadrupole static attraction ion trap. The charge transfer energy is estimated from the experimentally observed products. PBE0/6-311 +G(d)//B3LYP/6-31 G(d) level of DFT calculations are conducted to investigate the mechanism of charge transfer from ambient gas ion. The calculation of the difference of ionization energies and mismatch of orbital energies between decaborane and ambient gas reveals the mechanism of ionization.
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We present a first-principles lattice dynamics for the assembly of the transition-metal (M)-encapsulated Si_n clusters in amorphous phase (a-MSi_n), which has been proposed as a potential candidate for the channel material of the ...
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We present a first-principles lattice dynamics for the assembly of the transition-metal (M)-encapsulated Si_n clusters in amorphous phase (a-MSi_n), which has been proposed as a potential candidate for the channel material of the next-generation thin-film transistors (TFTs) [N. Uchida el al, Appl. Pfrys. Express 1, 121502 (2008)]. The shape of calculated vibrational density of states (VDOS) curve of a-MoSi_(10) is similar to the counterpart of the high pressure phase of a-Si (HPA-Si) although the present systems are obtained as a result of pressure relaxation. Its radial distribution function (RDF) among Si themselves is characterized by the absence of a gap between the first and second shells, which is also the case in . We further present the VDOS of a-WSi_(10), whose curve shape is again similar to that of HPA-Si. A difference between a-MoSi_(10) and a-WSi_(10) is that the W-atom displacement components extracted from the vibration eigenvectors are mainly distributed over a lower frequency range (< ～ 150 cm~(-1)) than the Mo counterpart (～ 150 cm~(-1) to ～300 cm~(-1)). This may be attributed to a larger atomic mass of W than Mo.
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摘要 :
We present the ionization of decaborane (B_(10)H_(14)) and formation of hydrogen- and boron-contents-controlled B_(10-y)H_x~+ through the charge transfer from ambient gas ion to decaborane molecules in an external quadrupole stati...
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We present the ionization of decaborane (B_(10)H_(14)) and formation of hydrogen- and boron-contents-controlled B_(10-y)H_x~+ through the charge transfer from ambient gas ion to decaborane molecules in an external quadrupole static attraction ion trap. The charge transfer energy is estimated from the experimentally observed products. PBE0/6-31 1+G(d)//B3LYP/6-31G(d) level of DFT calculations are conducted to investigate the mechanism of charge transfer from ambient gas ion. The calculation of the difference of ionization energies and mismatch of orbital energies between decaborane and ambient gas reveals the mechanism of ionization.
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摘要 :
We present a first-principles lattice dynamics for the assembly of the transition-metal (M)-encapsulated Si_n clusters in amorphous phase (a-MSi_n), which has been proposed as a potential candidate for the channel material of the ...
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We present a first-principles lattice dynamics for the assembly of the transition-metal (M)-encapsulated Si_n clusters in amorphous phase (a-MSi_n), which has been proposed as a potential candidate for the channel material of the next-generation thin-film transistors (TFTs) [N. Uchida el al, Appl. Pfrys. Express 1, 121502 (2008)]. The shape of calculated vibrational density of states (VDOS) curve of a-MoSi_(10) is similar to the counterpart of the high pressure phase of a-Si (HPA-Si) although the present systems are obtained as a result of pressure relaxation. Its radial distribution function (RDF) among Si themselves is characterized by the absence of a gap between the first and second shells, which is also the case in . We further present the VDOS of a-WSi_(10), whose curve shape is again similar to that of HPA-Si. A difference between a-MoSi_(10) and a-WSi_(10) is that the W-atom displacement components extracted from the vibration eigenvectors are mainly distributed over a lower frequency range (< ～ 150 cm~(-1)) than the Mo counterpart (～ 150 cm~(-1) to ～300 cm~(-1)). This may be attributed to a larger atomic mass of W than Mo.
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Based on first-principles atomic structure optimization, we demonstrate that a single layer of Si atoms in graphene-like positions may become semiconducting upon attachment of transition metal atoms with six valence electrons such...
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Based on first-principles atomic structure optimization, we demonstrate that a single layer of Si atoms in graphene-like positions may become semiconducting upon attachment of transition metal atoms with six valence electrons such as Mo, W and Cr. The resultant chemical formula is (MSi_6)_n where M is either of Mo, W or Cr. We predict the indirect energy gaps, which are ～0.3 eV for M=Mo and ～0.2 eV for M=Cr and W with the generalized gradient approximation to the density functional theory. We find corrugation of the Si layer in the film-normal direction to occur for all of the three transition metal elements investigated. A possible cause of energy gap opening is discussed.
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摘要 :
The insertion of an amorphous WSi
n
(n = 12) film composed of W-atom-encapsulated Sin cage clusters is demonstrated to reduce the SBH to 0.32 eV at W/n-Si and to 0.51 eV at W/Ge/p-Si junctions, while significantly extending the es...
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The insertion of an amorphous WSi
n
(n = 12) film composed of W-atom-encapsulated Sin cage clusters is demonstrated to reduce the SBH to 0.32 eV at W/n-Si and to 0.51 eV at W/Ge/p-Si junctions, while significantly extending the estimated TDDB lifetime to > 10 years at 100 °C under 5 MV/cm stress for Cu MOS capacitors. This film was formed with an excellent contact hole coverage by using WF6 and SiH4 gas sources in a hot-wall thermal reactor. These film properties enable the direct Cu contact at S/D in CMOS.
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摘要 :
The insertion of an amorphous WSi
n
(n = 12) film composed of W-atom-encapsulated Sin cage clusters is demonstrated to reduce the SBH to 0.32 eV at W/n-Si and to 0.51 eV at W/Ge/p-Si junctions, while significantly extending the es...
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The insertion of an amorphous WSi
n
(n = 12) film composed of W-atom-encapsulated Sin cage clusters is demonstrated to reduce the SBH to 0.32 eV at W/n-Si and to 0.51 eV at W/Ge/p-Si junctions, while significantly extending the estimated TDDB lifetime to > 10 years at 100 °C under 5 MV/cm stress for Cu MOS capacitors. This film was formed with an excellent contact hole coverage by using WF6 and SiH4 gas sources in a hot-wall thermal reactor. These film properties enable the direct Cu contact at S/D in CMOS.
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