Selective epitaxial Si based layers and TiSi2 deposition by integrated chemical vapor deposition

Régolini, J. L.; Margail, J.; Bodnar, S.; Maury, Delphine; Morin, Christine

doi:10.1016/0169-4332(96)00340-6

Cited by 6 publications

(4 citation statements)

References 37 publications

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“…10 Employing an epitaxial silicon buffer layer is a potential solution to alleviate both the consumption and nucleation problems. Such a layer was actually used by Regolini et al 14,15 even though the reasons for using it were not specifically linked to arsenic. In the next subsection we consider arsenic redistribution with the insertion of an undoped silicon epitaxial layer.…”

Section: Resultsmentioning

confidence: 99%

“…Experimental results on arsenic redistribution during TiSi 2 CVD were also reported by Regolini et al and Gouy-Pailler et al in France 12,13 who observed similar arsenic loss into the silicide. A selectively deposited epitaxial silicon buffer layer was proposed as a potential solution 14,15 and device performance comparable to conventional SALICIDE was reported. However, these reports did not include a detailed study of arsenic redistribution in the buffer layer during CVD.…”

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confidence: 99%

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Arsenic Redistribution during Rapid Thermal Chemical Vapor Deposition of TiSi[sub 2] on Si

Fang

Öztürk

O’Neil

et al. 2001

J. Electrochem. Soc.

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This paper studies the redistribution behavior of implanted arsenic during selective rapid thermal chemical vapor deposition of titanium disilicide (TiSi 2 ). The arsenic implant doses ranged from 3 ϫ 10 14 cm Ϫ2 to 5 ϫ 10 15 cm Ϫ2 . The TiSi 2 films were deposited either directly on arsenic-implanted silicon substrates or on epitaxial silicon buffer layers selectively deposited with varying thicknesses before TiSi 2 depositions. SiH 4 and TiCl 4 were used as precursors for TiSi 2 depositions and Si 2 H 6 and Cl 2 for selective silicon epitaxial growth. Experimental data revealed that the majority of the implanted arsenic was lost from the silicon substrate into the deposited TiSi 2 films when epitaxial silicon buffer layers were not employed. With the inclusion of the buffer layer, the arsenic loss could be reduced significantly. The loss of arsenic observed could not be explained by considering substrate consumption alone. In both cases, arsenic exhibited strongly enhanced out-diffusion from the silicon substrate into the TiSi 2 film. The injection of vacancies during the TiSi 2 depositions has been proposed as the reason for this enhanced out-diffusion. Monte Carlo simulations have been performed to verify the proposed model. Titanium disilicide (TiSi 2 ) is widely used to form low resistivity contacts to silicon devices. 1 Self-aligned silicide ͑SALICIDE͒ technology is used to form TiSi 2 on source/drain junctions and polysilicon gate electrodes of complementary metal-oxide-silicon ͑CMOS͒ devices. 2 As device dimensions shrink into the deep submicrometer regime, reducing the silicon substrate consumption and achieving the low resistivity C54 phase of TiSi 2 is becoming much more difficult. 3 Selective chemical vapor deposition ͑CVD͒ of TiSi 2 offers an alternative process solution with the potential to alleviate these problems. By introducing titanium and silicon from gaseous sources, TiSi 2 can be formed without substrate consumption. 4,5 Preliminary results have shown that formation of TiSi 2 on fine polysilicon lines can also be improved by CVD. 6 Because TiSi 2 is formed simultaneously on source/drain and polysilicon gate electrodes doped with different impurities, it is important to study the interactions between silicide formation and dopant redistribution in silicon. Extensive research has been carried out on this topic. 7-9 It was found that dopants in Si reduce the silicide growth rate, with arsenic having the strongest impact. Furthermore, during conventional TiSi 2 formation, dopants easily diffuse into the growing silicide without a ''snow plow'' effect. A recent study from this laboratory explored selective CVD of TiSi 2 on heavily arsenicdoped substrates. 10 It was found that arsenic introduces a barrier to TiSi 2 nucleation and results in enhanced substrate consumption. It was also shown that arsenic displays a strong tendency to diffuse into TiSi 2 during deposition. Arsenic loss into TiSi 2 during CVD processing was also observed by Southwell et al. 11 They attributed the effect to the injec...

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Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

Arsenic Redistribution during Rapid Thermal Chemical Vapor Deposition of TiSi[sub 2] on Si

Fang

Öztürk

O’Neil

et al. 2001

J. Electrochem. Soc.

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“…21 Most studies on CVD TiSi 2 have concentrated mainly on understanding the first principles of the process on undoped or moderately doped substrates, or on heavily doped silicon with an undoped silicon epitaxial interlayer. 22,23 Only a few studies exist concerning TiSi 2 deposition on heavily doped substrates. [24][25][26][27] It appears, however, that arsenic does effect deposition and consumption.…”

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confidence: 99%

Effects of Arsenic Doping on Chemical Vapor Deposition of Titanium Silicide

Fang¹,

Öztürk²,

Seebauer

et al. 1999

J. Electrochem. Soc.

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Titanium silicide (TiSi 2 ) has long been used in complementary metal oxide silicon (CMOS) integrated circuits because of its low resistivity and compatibility with standard processes. 1 With the scaling of device dimensions into the deep submicron regime, two problems related to the conventional self-aligned silicide (SALICIDE) process have emerged. The first problem is the so-called narrow-line effect which describes the difficulty in conversion of TiSi 2 from the high resistivity C49 phase into the low resistivity C54 phase on narrow polysilicon lines. 2 Several new growth methods have been suggested to solve this problem, including the use of titanium alloys 3 and molybdenum implants. 4 The second problem is the silicon substrate consumption during silicide formation, which makes the SALICIDE process incompatible with ultrashallow junctions. Metal oxide semiconductor field effects transistor (MOSFETs) with elevated source/ drain structures have been proposed to address this problem. 5,6 Selective chemical vapor deposition (CVD) of TiSi 2 has been proposed as an alternative process to form contacts to ultrashallow junctions without silicon consumption. It has also been suggested that C49-C54 conversion occurs more readily for this process although this area still lacks an in-depth investigation. The CVD process was first introduced by Tedrow et al. 7 in 1985, and it has attracted considerable interest from researchers in U.S., Japan, and France. [8][9][10][11][12][13][14][15][16] Silicides are formed on heavily doped source/drain regions and polycrystalline silicon gates. For the conventional SALICIDE process, the effects of dopants on the formation and characteristics of silicides have been extensively studied. For TiSi 2 , several general remarks can be made: (i) TiSi 2 growth rate depends on dopant type and concentration. The growth rate is highest on undoped and borondoped substrates, lower on heavily phosphorous-doped substrates, and lowest on heavily arsenic-doped substrates 17,18 ; (ii) Ti reacts with boron and arsenic to form stable compounds such as TiAs and TiB 2 , which makes TiSi 2 unsuitable as a dopant out-diffusion source to form junctions [18][19][20] ; (iii) TiSi 2 films formed on arsenic-doped substrates are thermally less stable. 21 Most studies on CVD TiSi 2 have concentrated mainly on understanding the first principles of the process on undoped or moderately doped substrates, or on heavily doped silicon with an undoped silicon epitaxial interlayer. 22,23 Only a few studies exist concerning TiSi 2 deposition on heavily doped substrates. [24][25][26][27] It appears, however, that arsenic does effect deposition and consumption. 25 In a recent report, 28 this group presented experimental results on TiSi 2 deposition on heavily boron-doped substrates. It was conclud-ed that implanted boron does not have a strong influence on the deposition process. Shallow p ϩ -n junctions (X j ϭ 1000 Å) with 800 Å thick TiSi 2 contacts were successfully fabricated. It was also shown by a preliminary experiment...

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“…The stability of the solid solution which in heavy metals is not easily perturbed and the chemical stability of heavy metals can be prevented. In addition to addressing environmental pollution [3][4][5][6] the excellent magnetic properties of iron [7], the associated adsorption, conductivity [8], cost-competitiveness and EMI shielding and other potential applications are some of the advantages [9].…”

Section: Introductionmentioning

confidence: 99%

Multi-Layered Effects of Fe on EMI Shielding of Sn-Al Hotel Architectural Powder

Hung

2016

MATEC Web Conf.

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.No evident effect in shielding efficiency is observed when the electromagnetic wave-absorbing coating materials were applied in single layers because of the dispersing nature of the powder. When increased to two-layer coating, shielding effects were evident at both high and low frequencies, with greater shielding efficiency at low frequencies over high frequencies. It is worth noting that when increased to three-layer coating, as the weight percentage of powdered Fe increased from 5% to 8% , the shielding efficiency of the powdered-Fe composite material was raised to -35 dB This shows that, as the weight percentage gets higher, the powder shows the resonance phenomenon of permeability spectrum, and at high frequencies, the electromagnetic wave shielding efficiency of the composite materials were greatly increased. As the weight percentage of the powered Fe were increased to 8% , we were unable to spread the powder evenly in the epoxy because of the dispersing characteristic in the electromagnetic properties of Fe and the anisotropic and heterogeneous nature of a powered composite material. During production, the powder aggregates often resulted in greater heterogeneity in the materials and consequently, lowered shielding efficiency at 3GHz.

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Selective epitaxial Si based layers and TiSi2 deposition by integrated chemical vapor deposition

Cited by 6 publications

References 37 publications

Arsenic Redistribution during Rapid Thermal Chemical Vapor Deposition of TiSi[sub 2] on Si

Arsenic Redistribution during Rapid Thermal Chemical Vapor Deposition of TiSi[sub 2] on Si

Effects of Arsenic Doping on Chemical Vapor Deposition of Titanium Silicide

Multi-Layered Effects of Fe on EMI Shielding of Sn-Al Hotel Architectural Powder

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