Fundamental study of atomic layer deposition in and on porous low-k films

Verdonck, Patrick; Delabie, Annelies; Swerts, Johan; Farrell, L.; Baklanov, Mikhaı̈l R.; Tielens, Hilde; Besien, Els Van; Witters, J.; Nyns, L.; Elshocht, Sven Van

doi:10.1109/iitc.2011.5940307

Cited by 4 publications

(4 citation statements)

References 5 publications

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“…Because the dielectric constant is highly sensitive to physical and chemical damage, a sealing layer is required to shield the pores from moisture, gas precursors, and plasma radicals that are involved in subsequent processing steps. Some authors have investigated the use of ALD to seal the pores of low- k dielectrics. − …”

Section: Introductionmentioning

confidence: 99%

In Situ Monitoring of Atomic Layer Deposition in Nanoporous Thin Films Using Ellipsometric Porosimetry

et al. 2012

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Ellipsometric porosimetry (EP) is a handy technique to characterize the porosity and pore size distribution of porous thin films with pore diameters in the range from below 1 nm up to 50 nm and for the characterization of porous low-k films especially. Atomic layer deposition (ALD) can be used to functionalize porous films and membranes, e.g., for the development of filtration and sensor devices and catalytic surfaces. In this work we report on the implementation of the EP technique onto an ALD reactor. This combination allowed us to employ EP for monitoring the modification of a porous thin film through ALD without removing the sample from the deposition setup. The potential of in situ EP for providing information about the effect of ALD coating on the accessible porosity, the pore radius distribution, the thickness, and mechanical properties of a porous film is demonstrated in the ALD of TiO(2) in a mesoporous silica film.

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Section: Introductionmentioning

confidence: 99%

In Situ Monitoring of Atomic Layer Deposition in Nanoporous Thin Films Using Ellipsometric Porosimetry

et al. 2012

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“…It has been demonstrated that for example gas permeance strongly depends on pore size and that the selectivity between He, N 2 , and SF 6 increases logarithmically as the pore size decreases (16). For the deposition of HfO 2 on porous low-k using HfCl 4 and H 2 O, it was shown that when the pore sized decreased as a result of the deposition, the porous material became first inaccessible for the larger HfCl 4 molecules, and only at a later stage for the smaller H 2 O molecules (17).…”

Section: Introductionmentioning

confidence: 99%

ALD Barrier Deposition on Porous Low-k Dielectric Materials for Interconnects

Elshocht¹,

Delabie²,

Dewilde³

et al. 2011

ECS Trans.

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To achieve very low permittivity values, advanced generations of low-k dielectrics for interconnects have a porous structure. Precursor penetration during metal barrier deposition by atomic layer deposition needs to be avoided not to degrade the low-k material properties. In this paper, we compare various options to seal a highly porous low-k material with a k-value of 2.0 against penetration during TaN ALD. This includes the exploration of a higher deposition temperature, the use of additional sealing layers, and the introduction of a short PVD Ta flash exposure prior to ALD. Depending on the technique used, pore penetration can be quasi completely avoided.

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“…For example, the decrease in mechanical strength of the porous ultralow- k (ULK) dielectrics may cause a premature package failure during chip-package interactions . Penetration of Cu and barrier metal precursors deep into the porous dielectrics is also a serious issue, which would hamper the precise control of critical dimensions (CDs) and the formation of continuous barriers, resulting in reliability degradation in ICs. , Recently, therefore, pore sealing of the porous ULK dielectrics has been intensively studied. While many types of methods have been proposed for this purpose, the drawbacks of each suggested method, such as an excessive increase of the dielectric thickness, , dielectric damage by plasmas, − a conformality issue, and difficulty in scalability, have limited their practical application to mass production.…”

mentioning

confidence: 99%

Surface-Localized Sealing of Porous Ultralow-k Dielectric Films with Ultrathin (<2 nm) Polymer Coating

Yoon¹,

Pak²,

Nam

et al. 2017

ACS Nano

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Semiconductor integrated circuit chip industries have been striving to introduce porous ultralow-k (ULK) dielectrics into the multilevel interconnection process in order to improve their chip operation speed by reducing capacitance along the signal path. To date, however, highly porous ULK dielectrics (porosity >40%, dielectric constant (k) <2.4) have not been successfully adopted in real devices because the porous nature causes many serious problems, including noncontinuous barrier deposition, penetration of the barrier metal, and reliability issues. Here, a method that allows porous ULK dielectrics to be successfully used with a multilevel interconnection scheme is presented. The surface of the porous ULK dielectric film (k = 2.0, porosity ∼47%) could be completely sealed by a thin (<2 nm) polymer deposited by a multistep initiated chemical vapor deposition (iCVD) process. Using the iCVD process, a thin pore-sealing layer was localized only to the surface of the porous ULK dielectric film, which could minimize the increase of k; the final effective k was less than 2.2, and the penetration of metal barrier precursors into the dielectric film was completely blocked. The pore-sealed ULK dielectric film also exhibited excellent long-term reliability comparable to a dense low-k dielectric film.

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Fundamental study of atomic layer deposition in and on porous low-k films

Cited by 4 publications

References 5 publications

In Situ Monitoring of Atomic Layer Deposition in Nanoporous Thin Films Using Ellipsometric Porosimetry

In Situ Monitoring of Atomic Layer Deposition in Nanoporous Thin Films Using Ellipsometric Porosimetry

ALD Barrier Deposition on Porous Low-k Dielectric Materials for Interconnects

Surface-Localized Sealing of Porous Ultralow-k Dielectric Films with Ultrathin (<2 nm) Polymer Coating

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