A selective CMP process for stacked low-k CVD oxide films

Hartmannsgruber, E.; Zwicker, G.; Beekmann, K.

doi:10.1016/s0167-9317(99)00264-6

Cited by 27 publications

(12 citation statements)

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“…Hartmannsgruber et al 12 studied the CMP removal selectivity between the low-k Flowfill layer and PECVD oxide layer, reporting an increasing low-k removal rate and a decreasing or nearconstant PECVD oxide removal rate with increasing additive concentration in the slurry. Hara et al 13,14 studied CMP of FLARE and fluorinated carbon with fumed SiO 2 , MnO 2 , Mn 2 O 3 , and CeO 2 slurries.…”

Section: Literature Reviewmentioning

confidence: 99%

Effects of CMP Process Conditions on Defect Generation in Low-k Materials

Chandrasekaran

Ramarajan

Lee

et al. 2004

J. Electrochem. Soc.

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The effects of chemical mechanical planarization ͑CMP͒ process parameters and consumables on the polish rate and defects generated in various low-k materials with k values ranging from 2.2 to 3.0 were studied in detail. The process consumables and conditions evaluated include slurry material ͑alumina and silica͒, pad type ͑soft and hard͒, polish pressure, and polish time. Atomic force microscopy ͑AFM͒ images and roughness numbers were used to evaluate the post-CMP defect generation under various process conditions and revealed nano/microscratches, pits, voids, and film delamination. For a given material, the removal rate increased with increasing pressure. The dependence of defects on pressure appeared highly driven by the slurry material, pad type, and low-k material properties. Defects increased with increasing pad hardness and decreasing k values. The increasing defects with decreasing k value can be attributed to the lower elastic modulus observed with low-k materials. Removal rates exhibited both a decrease and an increase in conjunction with polish time, depending on the type of low-k material used. AFM analysis showed an improvement in global surface roughness with increasing polish time; however, an increase in localized defects such as pits was also observed. Fourier transform infrared and X-ray photoelectron spectroscopy analyses showed no change in film chemistry under the conditions studied here.With advancements in ultralarge-scale integration, integrated microelectronic device dimensions are continually being scaled down. At present, manufacturers are running 0.11 m technology in their production lines, which increases the number of dies per wafer and reduces manufacturing costs. In addition, higher device speed requirements have forced the industry to include material changes in the device interconnection array. For example, in an attempt to reduce the resistance-capacitance time delay, manufacturers have moved toward a copper damascene process, with copper replacing aluminum and low-k dielectric materials replacing SiO 2 .Chemical mechanical planarization ͑CMP͒ is an important step in the copper damascene process. Copper deposited in the patterned dielectric trenches is planarized by CMP. The primary objective of the Cu-CMP process is to planarize and remove excess copper and the barrier layer. During this process, the underlying dielectric material is exposed. With industry shifts toward ultra low-k materials, very low k values can usually be achieved by using porous/organic materials, which also exhibit low hardness and modulus. However, these relatively weak materials cannot withstand the rigorous CMP process. Additionally, low-k films are less moisture resistant than conventional oxides produced by chemical vapor deposition ͑CVD͒; thus, extended exposure to CMP slurries and the environment affects their properties.Numerous low-k materials are being investigated. The compatibility of these materials with the CMP process is a significant factor in determining the appropriate low-k material to us...

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Section: Literature Reviewmentioning

confidence: 99%

Effects of CMP Process Conditions on Defect Generation in Low-k Materials

Chandrasekaran

Ramarajan

Lee

et al. 2004

J. Electrochem. Soc.

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“…In microelectronic industry many researchers have been actively working toward finding threshold values of hardness and elastic modulus that can provide Cu/low-k system the ability to withstand CMP and wire bonding processes [28][29][30]. Researchers at Motorola [43] have concluded that passing the CMP process of low-k material is not a simple factor of modulus, hardness, adhesion or toughness, but a combination of all of these properties.…”

Section: Mechanical Characterization Of Low-k Structures By Using Nanmentioning

confidence: 99%

Mechanical Characterization of Black Diamond (Low-k) Structures for 3D Integrated Circuit and Packaging Applications

Sekhar¹

2012

Nanoindentation in Materials Science

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“…Chemical mechanical polishing (CMP) is a key enabler for global and local planarization and has been intensively investigated from various angles [3,4]. According to the standard dual-damascene interconnect process for copper, the barrier layer (Ta/TaN, Mo, Co, Ru, and their alloy) is deposited onto the dielectric prior to the electroplating of copper [5,6].…”

Section: Introductionmentioning

confidence: 99%

Tribocorrosion Study of Copper During Chemical Mechanical Polishing in Potassium Periodate-Based Slurry

et al. 2015

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Copper chemical mechanical polishing (CMP) in barrier layer slurries with periodate as oxidant has not been intensively studied. This work presents an investigation into copper tribocorrosion in potassium periodatebased slurries during CMP. The research focused on copper tribocorrosion behavior, the surface chemical and electrochemical reaction products, and the electrochemical mechanism during CMP. The copper surface film was characterized by Raman spectra experiments. Tribocorrosion tests combined with CMP chemical experiments were conducted to study the tribochemical behavior and wearaccelerated corrosion effect. The results show that copper corrosion is more severe in acid solutions than in alkaline conditions. The copper surface is mainly passivated with copper oxides, copper hydroxide, and copper iodide. Small amounts of copper iodate, copper periodate, and iodine could be detected under specific pH conditions. Abrasion could help to get a uniform passivation film on copper surface consisting of copper oxides, copper hydroxide, and copper iodide only. The material loss due to wear-accelerated corrosion during CMP was also investigated. The results show that under weakly alkaline conditions (pH 9 and pH 10), the wear-corrosion effect plays an important role in the total material loss due to corrosion. The wearaccelerated corrosion is mainly caused by the exposure of more cathodic reaction sites to the slurry for participation in the redox reaction and the local galvanic corrosion during the CMP process. The high wear corrosion proportion of the total corrosion (DI c /I cc ) could help to obtain a better surface quality and desirable material removal rate during CMP.

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A selective CMP process for stacked low-k CVD oxide films

Cited by 27 publications

References 0 publications

Effects of CMP Process Conditions on Defect Generation in Low-k Materials

Effects of CMP Process Conditions on Defect Generation in Low-k Materials

Mechanical Characterization of Black Diamond (Low-k) Structures for 3D Integrated Circuit and Packaging Applications

Tribocorrosion Study of Copper During Chemical Mechanical Polishing in Potassium Periodate-Based Slurry

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