Effect of retaining ring slot designs and polishing conditions on slurry flow dynamics at bow wave

Liao, Xiaoxin; Sampurno, Yasa; Zhuang, Yun; Rice, Adam; Sudargho, Fransisca; Philipossian, Ara; Wargo, Christopher

doi:10.1016/j.mee.2012.06.002

Cited by 14 publications

(25 citation statements)

References 3 publications

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“…15 A brief description of the image capturing method is summarized below while a more detailed description can be found elsewhere. 13 UV light is projected onto the area of interest on the pad. The slurry is tagged with a special fluorescence dye.…”

Section: Resultsmentioning

confidence: 99%

“…Redistribution subject to ECS terms of use (see 18.236.120. 13 Downloaded on 2018-05-12 to IP 45 seconds between wafer polishes at a conditioning down-force of 59.2 N. Each wafer was polished for 1 minute at 22.8 kPa and 0.71 m/s. Prior to wafer polishing, the diamond disc was used to break in each pad for 15 minutes with DI water.…”

Section: 18mentioning

confidence: 99%

“…5,[11][12][13][14][15] Using the SIS, fresh slurry is introduced through an injector which is placed on the pad surface, as shown in Fig. 1b.…”

mentioning

confidence: 99%

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Effect of Pad Groove Design on Slurry Injection Scheme during Interlayer Dielectric Chemical Mechanical Planarization

Sampurno

Liao

et al. 2015

ECS J. Solid State Sci. Technol.

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In this study, the effect of pad groove design on slurry injection scheme during interlayer dielectric chemical mechanical planarization was investigated. A novel slurry injection system (SIS) with multiple slurry outlets was designed to allow fresh slurry to be injected through one or multiple points. At first, the SIS with one injection point scheme was compared with the standard slurry application method on a concentrically grooved pad and an xy-groove pad. On the concentrically grooved pad, the SIS with one injection point scheme generated significantly higher oxide removal rates (ranging from 22 to 35 percent) compared to the standard slurry application method at different slurry flow rates. On the xy-groove pad, the SIS with one injection point scheme still resulted in higher removal rates (ranging from 3 to 9 percent), however, its removal rate enhancement was not as high as that of the concentrically grooved pad. In order to further improve slurry availability on the xy-groove pad, SIS with multi-injection point scheme was tested. Results showed that the SIS with multi-injection point scheme resulted in significantly higher removal rates (ranging from 17 to 20 percent) compared to the standard slurry application method. This work underscored the importance of optimum slurry injection scheme for accommodating particular pad groove designs. Chemical mechanical planarization (CMP) has been widely used in the integrated circuit (IC) processing industry to achieve both local and global surface planarity through combined chemical and mechanical actions.1,2 Slurry, one of the consumables, represents almost half of the total cost of ownership (COO) of the CMP module.3 It also contains environmentally harmful chemicals. In the current state-ofthe-art CMP processes, fresh slurry is applied on the pad center area through a single tube (called standard slurry application method), as shown in Fig. 1a. Platen-wafer rotation, pad grooves and the retaining ring help transport the fresh slurry to the pad-wafer interface. In some processes, a significant portion of the fresh slurry flows directly off the pad surface without ever entering the pad-wafer interface due to the retaining ring and inertial forces. On the other hand, some slurry that has passed under the wafer stays on the pad (referred as used slurry), mixes with the fresh slurry and re-enters the pad-wafer interface. The chemicals in the used slurry may become less reactive and hence may decrease material removal rate as they continue to reside on the pad surface. 4 Furthermore, large amounts of deionized (DI) water is typically used to rinse the pad between wafer polishes. At the end of the pad rinse step, appreciable DI water stays on the pad surface. When the fresh slurry is introduced to polish the next wafer, it mixes with the residual rinse water and gets diluted (referred as dilution effect), resulting in a lower material removal rate.5 As such, the standard slurry application method does not provide efficient slurry utilization. A previous study has sho...

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Section: Resultsmentioning

confidence: 99%

Section: 18mentioning

confidence: 99%

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Effect of Pad Groove Design on Slurry Injection Scheme during Interlayer Dielectric Chemical Mechanical Planarization

Sampurno

Liao

et al. 2015

ECS J. Solid State Sci. Technol.

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“…In addition to the above series of polishing tests, an ultraviolet enhanced fluorescence (UVEF) technique was employed to qualitatively visualize slurry flow patterns and measure the availability of the slurry (i.e., its thickness) on the pad surface [ 21 , 22 ]. Before taking images, an embossed Politex pad (manufactured by Dow Electronic Materials, Newark, DE, USA)—which is softer compared to IC-1000—was conditioned using a 3M PB32A brush for 30 min with UPW at a conditioning force of 13.3 N. The Politex pad was employed because of its black color, not its mechanical properties, as in UVEF tests attaining superior color contrast between the fluorescing dye and the pad is critical.…”

Section: Methodsmentioning

confidence: 99%

“…As the slurry was tagged with a fluorescent dye (i.e., 4-methyl-umbelliferone), the UV light excited the dye in the slurry, causing it to fluoresce. The intensity of the emitted fluorescence was proportionate to the amount of the slurry (i.e., the thickness of the slurry film) [ 21 , 22 ]. A high-resolution charged coupled device camera was employed to record the emission of fluorescent light on the leading edge of the wafer carrier head.…”

Section: Methodsmentioning

confidence: 99%

Slurry Injection Schemes on the Extent of Slurry Mixing and Availability during Chemical Mechanical Planarization

et al. 2017

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In this study, slurry availability and the extent of the slurry mixing (i.e., among fresh slurry, spent slurry, and residual rinse-water) were varied via three different injection schemes. An ultraviolet enhanced fluorescence technique was employed to qualitatively indicate slurry availability and its flow on the pad during polishing. This study investigated standard pad center area slurry application and a slurry injection system (SIS) that covered only the outer half of the wafer track. Results indicated that the radial position of slurry injection and the alteration of fluid mechanics by the SIS played important roles in slurry mixing characteristics and availability atop the pad. Removal rates were found to decrease with slurry availability, while a higher degree of slurry mixing decreased the fraction of fresh slurry and consequently lowered the removal rate. By using a hybrid system (i.e., a combination of slurry injection via SIS and standard pad center slurry application), the polishing process benefited from higher slurry availability and higher fraction of fresh slurry than the conventional pad center slurry application and the shorter SIS, individually. This work underscores the importance of optimum slurry injection geometry and flow for obtaining a more cost-effective and environmentally benign chemical mechanical planarization process.

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Enhancing resistance of poly(ether ketone ketone) to high‐temperature steam through crosslinking and crystallization control

Veazey

Hsu²,

Gomez

2019

J of Applied Polymer Sci

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Poly(aryl ether ketone)s (PAEKs) are promising materials for harsh environments, such as in high‐temperature steam applications. Here, the effect of high‐temperature steam on the crystallinity and mechanical properties of existing poly(ether ether ketone) (PEEK) and PEKK(T/I) polymers is investigated. Differential scanning calorimetry (DSC), wide‐angle X‐ray scattering or diffraction (WAXD), and dynamic mechanical analysis experiments show these materials undergo significant crystallization and reorganization after prolonged exposure to steam and suffer from embrittlement. In addition, we show that xanthydrol‐based crosslinks can provide the dimensional stability and stabilize the PEKK crystal structure. Mechanical tests demonstrate that the ductility is preserved for longer exposures to steam compared to neat PEKK, whereas DSC and WAXD data indicate xanthydrol crosslinks effectively stabilize the crystal structure against steam‐assisted crystallization. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47727.

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Effect of retaining ring slot designs and polishing conditions on slurry flow dynamics at bow wave

Cited by 14 publications

References 3 publications

Effect of Pad Groove Design on Slurry Injection Scheme during Interlayer Dielectric Chemical Mechanical Planarization

Effect of Pad Groove Design on Slurry Injection Scheme during Interlayer Dielectric Chemical Mechanical Planarization

Slurry Injection Schemes on the Extent of Slurry Mixing and Availability during Chemical Mechanical Planarization

Enhancing resistance of poly(ether ketone ketone) to high‐temperature steam through crosslinking and crystallization control

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