Amorphous Ta-Si-N diffusion barriers in Si/Al and Si/Cu metallizations

Kolawa, E.; Pokela, P.J.; Reid, J.S.; Chen, J.S.; Nicolet, M.‐A.

doi:10.1016/0169-4332(91)90288-u

Cited by 40 publications

(19 citation statements)

References 6 publications

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“…16 The binary and ternary amorphous alloys of TaSi and TaSiN offer very high reaction temperature rates with copper. Kolawa et al 17 showed that Ta 74 Si 26 has a crystallization temperature of ~650°C when it is in contact with copper. It was also shown that Ta 36 Si 14 N 50 crystallizes at about 1100°C and retains its integrity when in contact with copper at temperatures as high as 950°C.…”

Section: Barrier Materialsmentioning

confidence: 99%

Barrier layers for Cu ULSI metallization

Shacham‐Diamand

2001

Journal of Elec Materi

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Barrier layers are integral parts of many metal interconnect systems. In this paper we review the current status of barrier layers for copper metallization for ultra-large-scale-integration (ULSI) technology for integrated circuits (ICs) manufacturing. The role of barrier layers is reviewed and the criteria that determine the process window, i.e. the optimum barrier thickness and the deposition processes, for their manufacturing are discussed. Various deposition methods are presented: physical vapor deposition (PVD), chemical vapor deposition (CVD), electrochemical deposition (ECD), electroless deposition (ELD), and atomic layer CVD (ALCVD) for barrier layers implementation. The barrier integration methods and the interaction between the barrier and the copper metallization are presented and discussed. Finally, the common inspection and metrology for barrier layer are critically reviewed.

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Section: Barrier Materialsmentioning

confidence: 99%

Barrier layers for Cu ULSI metallization

Shacham‐Diamand

2001

Journal of Elec Materi

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“…10 Ta x Si y N z alloys (TaSiN in the following) are amorphous, ternary mixtures of the three elements which are electrically conductive over a wide range of compositions. TaSiN films prepared by reactive sputtering of Ta 5 -Si 3 targets with compositions in the range of Ta : Si : N 35 : 15 : 50 have been shown to be robust diffusion barriers with low resistivities (,1000 mV cm) for Cu, Al, and Au when annealed in nonoxidizing ambients at 750-900 ± C. 11 Furthermore, it has recently been reported that for certain compositions, TaSiN films can act as diffusion barriers to oxygen at 650 ± C. 8 In this study we have investigated the optimization of composition and structure of layered TaSiN films for prevention of oxidation of a Si underlayer as well as maintenance of low electrical resistivity under high-temperature oxidation, up to 700 ± C. In addition, we document problems encountered when annealing the TaSiN layers in direct contact with a high-e perovskite layer and suggest strategies to optimize the device structure.…”

Section: Introductionmentioning

confidence: 99%

Layered TaSiN as an Oxidation Resistant Electrically Conductive Barrier

1999

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TaSiN films deposited as layered TaN-SiN structures of various compositions have been examined for their oxidation resistant properties during annealing in oxygen at annealing conditions commonly used to prepare perovskite dielectrics. The films have been characterized by Rutherford backscattering analysis (RBS), x-ray diffraction (XRD), and electrical resistivity measurements. Films with less than 15 at.% Si showed some resistance to oxidation after annealing for 1 min at 650 ± C but became fully oxidized after longer anneals. Increasing the Si content up to 28 at.% increasingly improved the oxidation resistance of the alloys to the point where the films resisted complete oxidation for up to 5 min at 700 ± C. For alloys with greater than 28 at.% Si, no oxidation could be detected by RBS or electrical measurements for anneals up to 5 min at 700 ± C. Furthermore, these high Si content alloys were still conductive with resistivities of near 1000 mV cm. It was also found that TaSiN and lead lanthanum titanate (PLT) interact strongly during annealing, and another nonoxidizing barrier metal, such as Pt, is required between the two materials if TaSiN is to be used as an electrode/barrier with lead-based perovskites.

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“…High nitrogen additions raise the stability to as high as 700°C by forming Ta2N.124 However, above this temperature, Ta reacts with Si to form TaSi,, with Cu diffusing rapidly as a result.12s Stability depends on both deposition and annealing conditions.126 Electrical measurement of amorphous Ta-Si-N structures has been shown to extend the stability to above 900°C through elimination of high-diffusivity grain-boundary paths.L23J27 Stability loss is achieved through a premature recrystallization of the alloy. 128 Using the diode configuration, a tungsten barrier layer has been reported to prevent Cu migration up to 500°C. 129 The barrier performance of a TiW layer has been examined as well.…”

Section: Adhesion Promoters and Diffusion Barriersmentioning

confidence: 99%

Copper metallization for ULSL and beyond

Murarka

Hymes

1995

Critical Reviews in Solid State and Materials Sciences

236

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The investigation of copper for use as an interconnection metal in the ultra large-scale integration (ULSI) era of silicon integrated circuits has accelerated in the past several years. The obvious advantages for using copper to replace currently used Al are related to its lower resistivity (1.7 pR-cm vs. 2.7 @-cm for Al) and its higher electromigration resistance (several orders of magnitude higher compared with Al). The goal of this review is to examine the properties of copper and its applicability as the interconnection metal. A comparison of electromigration behavior of various possible interconnection metal in standard "bulk" state is made. This is followed by a review of the calculations made comparing (a) the RC (resistance x capacitance) time constants of various material systems and (b) the joule heating of the interconnection materials. A comparative study of various metal systems for the application as the interconnect metal is then made. These discussions will clearly establish the superiority of copper over other metals despite certain limitations of copper. We then review the properties, both physical and chemical, and materials science of copper. The concept of using alloys of copper with a minimal sacrifice on resistivity to gain reliability is also discussed. This is followed by the review of the deposition, pattern definition and etching. passivation, need of the diffusion barrier (DB) and adhesion promoter (AP), planarization and dual damascene process using chemical mechanical planarization, and reliability. This review shows that copper will satisfy the needs of the future integrated circuits and provide high performance and reliability as long as we provide an appropriate barrier to diffusion in the underlying devices and the dielectric.

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Amorphous Ta-Si-N diffusion barriers in Si/Al and Si/Cu metallizations

Cited by 40 publications

References 6 publications

Barrier layers for Cu ULSI metallization

Barrier layers for Cu ULSI metallization

Layered TaSiN as an Oxidation Resistant Electrically Conductive Barrier

Copper metallization for ULSL and beyond

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