TiN barrier integrity and volcano formation in W-plug applications

Parikh, S.; Aksel'rod, L. M.; Gardner, JE; Armstrong, Karl; Parekh, N.

doi:10.1016/s0040-6090(97)01061-4

Cited by 10 publications

(7 citation statements)

References 4 publications

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“…6 The via fails electrically, and this failure has been dubbed the "volcano reaction." [7][8][9] While the basic mechanism of the failure, penetration of excess byproduct fluorine into the contact titanium film to form TiF x , has been elucidated, the factors that influence the reaction have not. Immediate "fixes" to avoid volcano formation, such as increasing the thickness of the TiN diffusion barrier, often come with the penalty of increased resistance in the via.…”

mentioning

confidence: 99%

“Volcano” Reactions in Oxide Vias Between Tungsten CVD and Bias Sputtered TiN/Ti Films

Herner

Tanaka

Zhang

et al. 2000

J. Electrochem. Soc.

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Tungsten chemical vapor deposition (CVD) remains the preferred method to make vertical metal interconnects in oxide vias on silicon integrated circuits. Vias are lined with thin titanium films, protected by a TiN diffusion barrier deposited on top followed by tungsten CVD. “Volcano” reactions, which result in rupture of the TiN barrier and electrical failure of the interconnect, remains an integration difficulty of great interest. Four parameters are found to strongly influence volcano reactions: the mixture of WF6 and SiH4 gases during tungsten nucleation film deposition, TiN barrier thickness, use of plasma preclean before Ti/TiN deposition, and a rapid thermal anneal after Ti/TiN deposition and before tungsten CVD. We describe process methods to avoid volcano reactions with thin TiN barrier films, maintaining low resistivity in the via. The influence of varying these parameters on overall step coverage is also discussed. © 2000 The Electrochemical Society. All rights reserved.

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confidence: 99%

“Volcano” Reactions in Oxide Vias Between Tungsten CVD and Bias Sputtered TiN/Ti Films

Herner

Tanaka

Zhang

et al. 2000

J. Electrochem. Soc.

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“…Ramanath et al 10 have shown that WF 6 can penetrate TiN and decompose deep in the film, allowing atomic F to diffuse into the underlying Ti film, increasing its resistivity and potentially leading to fatal "volcano" reactions. 8,11,12 Fluorine accumulation at the Ti/SiO 2 interface has also been linked to delamination of TiN/Ti films from SiO 2 . The diffusivity of F in Ti has been measured to bẽ 10 -12 cm 2 /s at 445°C.…”

mentioning

confidence: 99%

Homogeneous Tungsten Chemical Vapor Deposition on Silane Pretreated Titanium Nitride

Herner

Desai

Mak

et al. 1999

Electrochem. Solid-State Lett.

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Homogeneous nucleation of tungsten chemical vapor deposition (CVD) films on metallorganic (MO) CVD TiN substrates has been achieved by pretreating the substrate with SiH 4 at a wafer susceptor temperature of 425°C. Deposition of approximately a monolayer of silicon from the SiH 4 pretreatment results in continuous, uniform tungsten films less than 200 Å thick. Tungsten nucleation films grown on MOCVD TiN without a SiH 4 pretreatment were heterogeneous, with tungsten islands not coalescing into a continuous film until the thickness reached 400 Å. Experimental results are presented along with implications for use of tungsten CVD for vertical interconnects in high aspect ratio vias.

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“…On the contrary, Figure 7b demonstrates a well filled-in deep contact with an aspect ratio of 12:1 under a 12 kÅ inter-layer dielectric (ILD) bowing profile by using SFD TiCl 4 -based TiN. Furthermore, the low temperature SFD TiCl 4 -based TiN process can also be served with the small via step-coverage issue for protecting the W-CVD WF 6 precursor penetration and improving the adhesion between the Coatings 2016, 6, 2 6 of 8 inter-metal dielectric (IMD), as shown in Figure 8. Based on these phenomena, it manifests that the CVD TiCl 4 -based TiN can not only be implemented in advanced small via applications but can also be adopted in high-aspect-ratio deep contacts with low temperature, high conformity and low resistance.…”

Section: Excellent Step Coverage Requirement For High Aspect Ratio Dementioning

confidence: 99%

“…TiN also meets the requirements for improving the adhesion properties between tungsten chemical vapor deposition (W-CVD) and oxide. The formation of a titanium silicide (TiSi x ) contact with a TiN barrier is currently being used to prevent the WF 6 from penetrating in the contact module, which then improves the adhesion performance by reacting to form a thin TiSi x layer. Fluoride penetration through the TiN results in junction leakage and the formation of volcano defects by a reaction with the underlying Ti [5,6].…”

Section: Introductionmentioning

confidence: 99%

“…The formation of a titanium silicide (TiSi x ) contact with a TiN barrier is currently being used to prevent the WF 6 from penetrating in the contact module, which then improves the adhesion performance by reacting to form a thin TiSi x layer. Fluoride penetration through the TiN results in junction leakage and the formation of volcano defects by a reaction with the underlying Ti [5,6]. Conventionally, Ti/TiN films grown by physical vapor deposition (PVD) exhibit poor step coverage and therefore are not suitable for submicron-integrated devices.…”

Section: Introductionmentioning

confidence: 99%

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TiCl4 Barrier Process Engineering in Semiconductor Manufacturing

et al. 2016

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Titanium nitride (TiN) not only was utilized in the wear-resistant coatings industry but it was also adopted in barrier processes for semiconductor manufacturing. Barrier processes include the titanium (Ti) and TiN processes, which are commonly used as diffusion barriers in via/contact applications. However, engineers frequently struggle at the via/contact module in the beginning of every technology node. As devices shrink, barrier processes become more challenging to overcome the both the physical fill-in and electrical performance requirements of advanced small via/contact plugs. The aim of this paper is to investigate various chemical vapor deposition (CVD) TiCl 4 -based barrier processes to serve the application of advanced small via/contact plugs and the metal gate processes. The results demonstrate that the plasma-enhanced chemical vapor deposition (PECVD) TiCl 4 -based Ti process needs to select a feasible process temperature to avoid Si surface corrosion by high-temperature chloride flow. Conventional high step coverage (HSC) CVD TiCl 4 -based TiN processes give much better impurity performance than metal organic chemical vapor deposition (MOCVD) TiN. However, the higher chloride content in HSC film may degrade the long-term reliability of the device. Furthermore, it is evidenced that a sequential flow deposition (SFD) CVD TiCl 4 -based process with multiple cycles can give much less chloride content, resulting in faster erase speeds and lower erase levels than that of conventional HSC TiN.

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TiN barrier integrity and volcano formation in W-plug applications

Cited by 10 publications

References 4 publications

“Volcano” Reactions in Oxide Vias Between Tungsten CVD and Bias Sputtered TiN/Ti Films

“Volcano” Reactions in Oxide Vias Between Tungsten CVD and Bias Sputtered TiN/Ti Films

Homogeneous Tungsten Chemical Vapor Deposition on Silane Pretreated Titanium Nitride

TiCl4 Barrier Process Engineering in Semiconductor Manufacturing

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