Homogeneous Tungsten Chemical Vapor Deposition on Silane Pretreated Titanium Nitride

Herner, S. B.; Desai, S. A.; Mak, A.; Ghanayem, S.

doi:10.1149/1.1390850

Cited by 21 publications

(20 citation statements)

References 11 publications

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“…The performance metric of the interconnect is denoted by the delay time τ experienced by an electrical signal traveling through it, which is expressed as τ = RC, where R = total equivalent resistance of interconnect lines, and C = total equivalent capacitance resulting from the interconnect lines and surrounding interlayer dielectrics (ILD) [9,10]. A manufacturable W interconnect structure requires a TiN adhesion layer for the W deposit and for the structure to remain intact through the chemical mechanical polishing (CMP) step, as well as a W nucleation layer to facilitate low-resistivity bulk W growth and to prevent TiN etching by Fradicals from the WF 6 precursor [11][12][13][14]. On the other hand, a manufacturable Cu interconnect structure comprises of a TaN/Ta barrier layer to prevent Cu diffusion in the ILD [15][16][17], and a seed layer of physical-vapor-deposited (PVD) Cu to provide nucleation for the subsequent electro-deposition to fill the Cu in the interconnect structure [18,19].…”

Section: Introductionmentioning

confidence: 99%

Effect of improved contact on reliability of sub-60 nm carbon nanotube vias

et al. 2016

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Advances in semiconductor technology due to the aggressive downward scaling of on-chip feature sizes have led to rapid rises in the resistivity and current density of interconnect conductors. As a result, current interconnect materials, Cu and W, are subject to performance and reliability constraints approaching or exceeding their physical limits. Therefore, alternative materials are being actively considered as potential replacements to meet such constraints. The carbon nanotube (CNT) is among the leading replacement candidates for on-chip interconnect vias due to its high aspect-ratio nanostructure and superior current-carrying capacity to Cu and W, as well as other potential candidates. Based on the results for 40 nm and 60 nm top-contact metallized CNT vias, we demonstrate that not only are their current-carrying capacities two orders of magnitude higher than their Cu and W counterparts, they are enhanced by reduced via resistance due to contact engineering facilitated by the first reported contact resistance extraction scheme for a 40 nm linewidth.

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Section: Introductionmentioning

confidence: 99%

Effect of improved contact on reliability of sub-60 nm carbon nanotube vias

et al. 2016

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“…1,2 Chemical-vapor-deposited ͑CVD͒ tungsten ͑W͒ is the preferred method to realize the filling of a high-aspect-ratio contact via or plug due to its superior step-coverage. [3][4][5][6] W is resistant to electromigration or stress migration due to its high melting point among pure metals ͑3387°C͒ and low resistivity ͑5.5 ⍀ cm͒.…”

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Investigation of Static Corrosion Between W Metals and TiN[sub x] Barriers in a W Chemical-Mechanical-Polishing Slurry

Hung

Wang

Lee

et al. 2008

J. Electrochem. Soc.

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In order to control the polishing qualities of tungsten ͑W͒ and titanium nitride ͑TiN x ͒ films in W chemical-mechanical-polishing ͑WCMP͒ processes, the electrochemical behavior between the W and the TiN x films deposited at various N 2 flow rates was examined in this study. Metrologies, including X-ray diffractrometry, Auger electron spectrometry, and scanning electron microscopy, were used to verify the physical properties of the TiN x films, while electrochemical analyses, including electrochemical impedance spectroscopy, potential dynamic curves, and potential difference measurements, were used to characterize the mechanism of galvanic corrosion between the W and the TiN x films deposited at various N 2 flow rates. The results show that the N content of the TiN x films influences not only the physical properties of the TiN x films but also the chemical activity in the WCMP slurries. The equivalent circuit, including the charge-transfer resistance and the titanium-oxide resistance associated with tantalumoxide capacitance, was built to characterize the mechanism of the galvanic corrosion between the W and the TiN x metals.Shrinking transistor sizes and the use of tall, three-dimensional capacitors in dynamic random access memory requires vertical interconnects ͑also called vias or plugs͒ in silicon integrated circuits. 1,2 Chemical-vapor-deposited ͑CVD͒ tungsten ͑W͒ is the preferred method to realize the filling of a high-aspect-ratio contact via or plug due to its superior step-coverage. 3-6 W is resistant to electromigration or stress migration due to its high melting point among pure metals ͑3387°C͒ and low resistivity ͑5.5 ⍀ cm͒.Prior to W deposition, titanium or its nitride ͑Ti/TiN x ͒ film is typically deposited as a glue layer because of the poor adhesion of W on SiO 2 substrates. [7][8][9][10][11] The TiN x film further acts as a diffusion barrier, which offers protection against the reaction of tungsten hexafluoride ͑WF 6 ͒ and Ti, avoiding the W "volcano" effect. The volcano phenomenon occurs when WF 6 gas penetrates through the weak sites of TiN x film and then rapidly reacts with the Ti underlayer, producing by-products of TiF 3 gas and solid W. The chemical formula for this reaction is as follows 10 WF 6͑g͒ + Ti ͑s͒ → TiF 3͑g͒ + W ͑s͒ ͓1͔The TiN x films are generally deposited using physical vapor deposition ͑PVD͒ or CVD. Conventional PVD-TiN x films have been widely used as barrier layers because of their high chemical stability and low resistivity compared to CVD-TiN x films. However, the stepcoverage of the PVD process for high-aspect-ratio features is extremely difficult to achieve. A CVD-TiN x film with a smaller overhang effect has been proposed as an alternative to the PVD-TiN x film. 12,13 After the glue layer and W deposition, overburdened metals are removed using W chemical-mechanical-polishing ͑WCMP͒ to define interconnects. 14,15 WCMP is adopted for the redundancy of defective metal etching and better electrical yields to improve the overall integration for multilevel interconnects. 16...

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“…A similar study of SiH 4 decomposition on TiN at 425°C and 90 Torr corroborates the deposition of a self-limiting monolayer of Si. 7 The self-limiting deposition of a Si seed on TiN is advantageous; the influence of the Si seed on the subsequently formed Ge device is minimized.…”

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Low Temperature Deposition and Crystallization of Large-Grained Ge Films on TiN

Herner¹

2006

Electrochem. Solid-State Lett.

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Germanium films were deposited by low-pressure chemical vapor deposition on TiN substrates using a Si seeding technique. By depositing a self-limiting Si film on TiN via SiH 4 decomposition at 380°C, a continuous, amorphous Ge film could subsequently be deposited by GeH 4 decomposition at 320°C. Amorphous Ge films were crystallized by thermal annealing at ജ405°C for 60 m. Polycrystalline Ge films on TiN are shown to have larger grains and fewer stacking faults when deposited amorphous and subsequently crystallized, compared to films polycrystalline as-deposited.

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Homogeneous Tungsten Chemical Vapor Deposition on Silane Pretreated Titanium Nitride

Cited by 21 publications

References 11 publications

Effect of improved contact on reliability of sub-60 nm carbon nanotube vias

Effect of improved contact on reliability of sub-60 nm carbon nanotube vias

Investigation of Static Corrosion Between W Metals and TiN[sub x] Barriers in a W Chemical-Mechanical-Polishing Slurry

Low Temperature Deposition and Crystallization of Large-Grained Ge Films on TiN

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