Review of planarization and reliability aspects of future interconnect materials

Sethuraman, Anantha R.; Wang, Jiun-Fang; Cook, Lee M.

doi:10.1007/bf02655585

Cited by 26 publications

(16 citation statements)

References 7 publications

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“…[1][2][3] The damascene process based on chemical mechanical polishing ͑CMP͒, which is used to remove the protruding part and planarize the whole wafer surface, makes it possible to use Cu as an interconnection material.…”

mentioning

confidence: 99%

Effects of OH Radicals on Formation of Cu Oxide and Polishing Performance in Cu Chemical Mechanical Polishing

Kang

Nam²,

Won³

et al. 2008

Electrochem. Solid-State Lett.

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The amount of OH radicals generated varied according to the complexing agent or Cu ion, and the accelerating effect of OH radicals on the rate of Cu oxide formation was found in acidic pH. When Cu͑I͒ ions and oxalic acid were added to H 2 O 2 -based slurry, the decreases in etch and removal rates of Cu were observed because more generation of OH radicals resulted in the formation of thicker Cu oxide compared to additive-free slurry. Therefore, proper control of the formation and dissolution of Cu oxide led to an increase in etch and removal rates.Cu has been introduced as an interconnection material due to its low electrical resistance and high resistance to electromigration compared to W or Al. 1-3 The damascene process based on chemical mechanical polishing ͑CMP͒, which is used to remove the protruding part and planarize the whole wafer surface, makes it possible to use Cu as an interconnection material.During Cu CMP, the Cu surface is oxidized by an oxidizing agent through the oxidation of Cu to cuprous or cupric ions ͑Eq. 1͒. Among such oxidizing agents, hydrogen peroxide ͑H 2 O 2 ͒ is widely used for Cu CMP and its properties have been widely investigated. 4-8 Also, various organic additives were added into the slurry to maximize specific characteristics during the Cu CMP. To inhibit Cu corrosion, benzotriazole ͑BTA͒ or 5-aminotetrazole ͑ATRA͒ is commonly used. 9-11 An organic additive of the carboxylic group was added as a complexing agent to improve the removal rate of Cu. At present, citric acid, 12-14 oxalic acid, 15 and glycine 16-18 were introduced as the complexing agent and their properties and performance investigated. The complexing agents react with oxidized Cu and form complexes on the Cu surface. In an acidic pH, Cu cations, especially Cu͑I͒ ions, react with H 2 O 2 and then H 2 O 2 is converted into OH radicals and hydroxyl ions through the so-called Fenton reaction ͑Eq. 2͒. 19 The oxidation potential of the OH radical is higher than that of H 2 O 2 , which is well known to be one of the most powerful oxidizing agents Cu → Cu + + e or Cu 2+ + 2e ͓1͔It has been reported that OH radicals enhanced the removal rates of Cu in an H 2 O 2 -based slurry, including an amino acid at alkaline solution, 16 and that citric acid and oxalic acid improved the removal rate of Cu in the acidic solution. When using citric acid and oxalic acid as the complexing agent in weak acidic pH, the effect of OH radicals in the slurry on Cu CMP performance has not been reported. Therefore, the objective of this study is to understand the effect of OH radicals on Cu CMP. ExperimentalElectrochemical measurements.-For the electrochemical experiments, a 99.9% Cu rod with a surface area of 0.5 cm 2 was used. A Pt electrode and a saturated calomel electrode ͑SCE͒ were used as a counter and a reference electrode, respectively. Potentiodynamic studies were performed with an EG&G model 263 potentiostat/ galvanostat corrosion measurement system. The potentiodynamic polarization measurements were obtained with a scan rate of 10 mV/s a...

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mentioning

confidence: 99%

Effects of OH Radicals on Formation of Cu Oxide and Polishing Performance in Cu Chemical Mechanical Polishing

Kang

Nam²,

Won³

et al. 2008

Electrochem. Solid-State Lett.

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“…The traditional planarization method using CMP (see Figure 5) can be used for planarized patterning of copper or aluminum [24] because of its pad and slurry. The traditional method can also be used for the planarized patterning of chrome with an adaptable pad and slurry.…”

Section: Chemical Mechanical Polishing (Cmp)mentioning

confidence: 99%

Improvement of High Dynamic Range Capacitive Displacement Sensor by a Globalm Planarization

Kang¹,

Moon²

2011

JST

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This study presents an improvement of high dynamic range contact-type capacitive displacement sensor by applying planarization. The sensor is called the contact-type linear encoder-like capacitive displacement sensor (CLECDiS), is a nano-meter-resolution sensor with a wide dynamic range. However, height differences due to patterned electrodes may cause a variety of problems or performance degradation. In devices of two glass wafer surfaces with patterned structures assembled face-to-face and in sliding contact, the heights of the patterns crucially affect their performance and practicality, so it should be planarized for reducing the problem. A number of techniques for planarizing glass wafer surfaces with patterned chrome electrodes were evaluated and the following three were selected as adequate: lift-off, etch-back, and chemical mechanical polishing (CMP). The fabricated samples showed that CMP provided the best planarization. CMP was successfully employed to produce CLECDiS with improved signal reliability due to reduced collisions between electrodes

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“…Zn 2 Te 3 O 8 ceramics with 4 wt% TiO 2 showed a reasonably good τ f of −8.7 ppm/°C with a Q u × f of 27,000 GHz, and a ɛ r of 19.3. However, these materials generally react with Ag 14 and thus a metal electrode made of Al has been proposed, 10 an option making these ceramics especially interesting for semiconductor devices where Al is also commonly used for metallizations 15 . The main aim of this work is to study the suitability of TiO 2 ‐doped Zn 2 Te 3 O 8 ceramics (ZTT) for tape casting.…”

Section: Introductionmentioning

confidence: 99%

“…However, these materials generally react with Ag 14 and thus a metal electrode made of Al has been proposed, 10 an option making these ceramics especially interesting for semiconductor devices where Al is also commonly used for metallizations. 15 The main aim of this work is to study the suitability of TiO 2 -doped Zn 2 Te 3 O 8 ceramics (ZTT) for tape casting. The dielectric properties of stacked and fired tapes with and without Al electrodes at low and high frequencies as well as the tape properties before and after sintering are presented.…”

Section: Introductionmentioning

confidence: 99%

Tape Casting and Dielectric Properties of Zn₂Te₃O₈‐Based Ceramics with an Ultra‐Low Sintering Temperature

Honkamo

Jantunen

Subodh³

et al. 2009

Int J Applied Ceramic Tech

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The suitability of dielectric ceramics made of zinc tellurate (Zn2Te3O8) and titanium dioxide (TiO2) with an ultra‐low sintering temperature (650°C) for tape casting and thus for the multimodule technique with Al electrodes was investigated. The properties of the tape before and after sintering as well as the amount of organic additives for the casting process and a thermal analysis of the tape up to 1000°C are reported. In addition, electrodes on a multilayer module made on stacked tapes were prepared using Al paste and postfiring, followed by relative permittivity and loss tangent measurements to verify the electrical performance of the whole structure. The dielectric properties of the stacked module without any electrodes were also measured. The results show that the composition is well suited for the tape process but extra care should be taken especially with the proper sintering temperature for optimized electrical performance.

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Review of planarization and reliability aspects of future interconnect materials

Cited by 26 publications

References 7 publications

Effects of OH Radicals on Formation of Cu Oxide and Polishing Performance in Cu Chemical Mechanical Polishing

Effects of OH Radicals on Formation of Cu Oxide and Polishing Performance in Cu Chemical Mechanical Polishing

Improvement of High Dynamic Range Capacitive Displacement Sensor by a Globalm Planarization

Tape Casting and Dielectric Properties of Zn₂Te₃O₈‐Based Ceramics with an Ultra‐Low Sintering Temperature

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Review of planarization and reliability aspects of future interconnect materials

Cited by 26 publications

References 7 publications

Effects of OH Radicals on Formation of Cu Oxide and Polishing Performance in Cu Chemical Mechanical Polishing

Effects of OH Radicals on Formation of Cu Oxide and Polishing Performance in Cu Chemical Mechanical Polishing

Improvement of High Dynamic Range Capacitive Displacement Sensor by a Globalm Planarization

Tape Casting and Dielectric Properties of Zn2Te3O8‐Based Ceramics with an Ultra‐Low Sintering Temperature

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Tape Casting and Dielectric Properties of Zn₂Te₃O₈‐Based Ceramics with an Ultra‐Low Sintering Temperature