Study of Pattern Density Effects in CMP Using Fixed Abrasive Pads

Gorantla, Venkata R. K.; Venigalla, R.; Economikos, Laertis; O’Connor, Daniel R.; Babu, S. V.

doi:10.1149/1.1627349

Cited by 5 publications

(4 citation statements)

References 9 publications

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“…They prepared a cylindrical polishing pad with cerium oxide abrasive resin, and the microstructure of chip itself is embedded in resin exposed the grain of abrasive pad called "polishing pad activation". The study shows that the polishing efficiency of chip surface is mainly affected by its pattern density, and its pattern density in different station also affected [19].…”

Section: Fixed Abrasive Chemical Mechanical Polishing Applicationsmentioning

confidence: 95%

Status and Trends of Fixed Abrasive Polishing on Semiconductor

Zhao

Zuo

Sun

2012

KEM

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The necessity of fixed abrasive CMP in polishing semiconductor materials processing was analyzed. Compared the shortcomings of traditional free abrasive polishing with the advantages of fixed abrasive polishing, the applications of fixed abrasive polishing technology in semiconductor processing were described. A variety of fixed abrasive polishing pad production methods were introduced. The development trend of fixed abrasive polishing was prospected.

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Section: Fixed Abrasive Chemical Mechanical Polishing Applicationsmentioning

confidence: 95%

Status and Trends of Fixed Abrasive Polishing on Semiconductor

Zhao

Zuo

Sun

2012

KEM

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“…At the module level, the MIT test-mask with its variable density and pitch structures is a very valuable tool for characterization and improvement of the CMP process capabilities ( 16) and analytical models are reported in multiple reports (17)(18)(19) relating CMP process knobs to critical WIWNU modulators such as dishing and erosion. A number of approaches such as higher selectivity slurry chemistries and fixed abrasive pads among others are reported as CMP module level actions to reduce WIWNU (20)(21)(22). Integrated approaches such as thicker incoming films and pre-profile modification through controlled etch-back processes do improve WIDNU at the expense of additional process flow complexity and increased cycle times (23)(24)(25)(26).…”

Section: Die-level or With-in-die Non-uniformity (Widnu)mentioning

confidence: 99%

A Modeling Study on the Layout Impact of With-In-Die Thickness Range for STI CMP

Kıncal

Basim

2013

ECS Trans.

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Chemical Mechanical Planarization process has a proven track record as an effective method for planarizing the wafer surface at multiple points of the semiconductor manufacturing flow. One of the most challenging aspects of the CMP process, particularly in applications like Shallow Trench Isolation (STI), is the difference in relative removal rates of the different materials that are being polished. A certain amount of over-polish is required to clear oxide on top of the nitride, however, this over-polish may also lead to significant problems like dishing and erosion (introducing additional topography after the film has been planarized). This work formulates a methodology to predict how this additional topography is modulated by incoming layout properties introducing a parameter to accurately characterize line and space width on a layout with random geometric shapes.

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“…For example, to minimize dishing and erosion in a shallow trench isolation ͑STI͒, a fixed abrasive ͑FA͒ pad consisting of ceria particles has been made commercially available. 12 In the conventional STI CMP, ceria is used as an abrasive, which then interacts with the silicon oxide surface by a chemical tooth model. In the FA pad, the ceria abrasives are fixed onto the pad, thereby minimizing the chemical interaction between the unexposed surfaces in the trenches and thereby minimizing dishing.…”

mentioning

confidence: 99%

1H-Benzotriazole Incorporated Pad for Chemical Mechanical Planarization of Copper

Jia

Venkataraman

et al. 2010

J. Electrochem. Soc.

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Chemical mechanical polishing ͑CMP͒ pads are generally designed to play a passive role in terms of chemical reactions that occur on the surface to be polished. For copper CMP, a pad that is capable of initiating and controlling various chemical reactions on the copper surface can bring another dimension of flexibility to the CMP process. This work investigates such a model pad for its potential applications in copper CMP. More specifically, the physical and chemical properties of a polyurethane pad containing 1H-benzotriazole ͑BTA͒ are examined. When applied to Cu blanket wafers, the BTA-containing pad yielded a higher removal rate compared to the conventional CMP process with the reference pad. For patterned wafer polishing, the results indicate that the BTA-containing pad is effective in improving the step height reduction efficiency and in minimizing dishing and erosion. The potential applications of a pad with such a design for gaining a fundamental understanding of the copper CMP process are discussed based on these experimental results.Chemical mechanical polishing ͑CMP͒ has become a main stream method in submicrometer integrated circuit manufacturing for its global and local planarization abilities, thereby more efficiently enabling the fabrication of multilevel interconnects. 1,2 The key consumables in a CMP process include pad, slurry, conditioner, and carrier. 3 During polishing, the pad carries the slurry and delivers it to the wafer surface. It also transmits the normal and shear forces from the polisher to the wafer. Therefore, the polishing pad plays a critical role in the CMP process and influences the outcomes such as removal rate ͑RR͒, step height reduction efficiency ͑SHRE͒, withinwafer nonuniformity ͑WIWNU͒, wafer-to-wafer nonuniformity, and defect counts. 4 The conventional Cu CMP slurry is comprised of an oxidizer, abrasive particles, passivating agent, and chelating agent. 5,6 Optional additives can be anions, surfactants, and rheological modifiers. The oxidizer commonly used is hydrogen peroxide ͑H 2 O 2 ͒ to generate copper ions from the surface. Among metal oxides, colloidal silica ͑SiO 2 ͒ has become the choice of abrasive particles in copper CMP due to its availability in various sizes, purity, and functionality. The passivating agent is often chosen from one of the azole derivatives such as benzotriazole ͑BTA͒, imidazole, or any organic compounds that can form an insoluble film on the Cu surface. The chelating agent can be any organic acids that can form water-soluble complexes. Examples of possible chelating agents include carboxylic acids and amino acids.The CMP process is well recognized for its power in providing global and local planarizations for wafer processing. 7 However, CMP processes also have disadvantages in terms of introducing defects such as dishing, erosion, scratches, and contamination. 8,9 Dishing and erosion affect the electrical resistance of interconnects because they change the dimension and properties of the cross section of the interconnects. 10 With the conven...

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Study of Pattern Density Effects in CMP Using Fixed Abrasive Pads

Cited by 5 publications

References 9 publications

Status and Trends of Fixed Abrasive Polishing on Semiconductor

Status and Trends of Fixed Abrasive Polishing on Semiconductor

A Modeling Study on the Layout Impact of With-In-Die Thickness Range for STI CMP

1H-Benzotriazole Incorporated Pad for Chemical Mechanical Planarization of Copper

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