Post-CMP cleaning of W and SiO2: a model study

Igor J. Malik; Jackie Zhang; Alan J. Jensen; Jeffrey J. Farber; Wilbur C. Krusell; Srini Raghavan; Chilkunda Rajhunath

doi:10.1557/proc-386-109

Post-CMP cleaning of W and SiO₂: a model study

Igor J. Malik, Jackie Zhang, Alan J. Jensen, Jeffrey J. Farber, Wilbur C. Krusell, Srini Raghavan, Chilkunda Rajhunath

Materials Science and Engineering

Research output: Contribution to journal › Conference article › peer-review

7 Scopus citations

Abstract

Chemical-Mechanical Planarization (CMP) of SiO₂ is performed using alkaline silica slurries while CMP of tungsten (W) utilizes acidic slurries with alumina as the abrasive. Proposed mechanisms for the two CMP processes, with more emphasis on SiO₂-CMP, have been discussed in literature. However, much less is known about the removal mechanism of residual slurry particles from the planarized surfaces - a crucial step for subsequent device processing. We discuss the chemical and physical basis of post-CMP cleaning by double-side scrubbing using polyvinyl alcohol (PVA) brushes and show how the interactions between the wafer surface, slurry, and the brush material affect the overall cleaning efficiency. Using the zeta potential concept the common features for cleaning surfaces after SiO₂-CMP and W-CMP are established and the differences between these two systems are highlighted. We present surface particle levels for two model systems as a function of cleaning chemistries and discuss their influence on post-CMP surface metal levels.

Original language	English (US)
Pages (from-to)	109-114
Number of pages	6
Journal	Materials Research Society Symposium - Proceedings
Volume	386
DOIs	https://doi.org/10.1557/proc-386-109
State	Published - 1995
Event	Proceedings of the 1995 MRS Spring Meeting - San Francisco, CA, USA Duration: Apr 17 1995 → Apr 21 1995

ASJC Scopus subject areas

General Materials Science
Condensed Matter Physics
Mechanics of Materials
Mechanical Engineering

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title = "Post-CMP cleaning of W and SiO2: a model study",

abstract = "Chemical-Mechanical Planarization (CMP) of SiO2 is performed using alkaline silica slurries while CMP of tungsten (W) utilizes acidic slurries with alumina as the abrasive. Proposed mechanisms for the two CMP processes, with more emphasis on SiO2-CMP, have been discussed in literature. However, much less is known about the removal mechanism of residual slurry particles from the planarized surfaces - a crucial step for subsequent device processing. We discuss the chemical and physical basis of post-CMP cleaning by double-side scrubbing using polyvinyl alcohol (PVA) brushes and show how the interactions between the wafer surface, slurry, and the brush material affect the overall cleaning efficiency. Using the zeta potential concept the common features for cleaning surfaces after SiO2-CMP and W-CMP are established and the differences between these two systems are highlighted. We present surface particle levels for two model systems as a function of cleaning chemistries and discuss their influence on post-CMP surface metal levels.",

author = "Malik, {Igor J.} and Jackie Zhang and Jensen, {Alan J.} and Farber, {Jeffrey J.} and Krusell, {Wilbur C.} and Srini Raghavan and Chilkunda Rajhunath",

year = "1995",

doi = "10.1557/proc-386-109",

language = "English (US)",

volume = "386",

pages = "109--114",

journal = "Materials Research Society Symposium - Proceedings",

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T2 - Proceedings of the 1995 MRS Spring Meeting

AU - Malik, Igor J.

AU - Zhang, Jackie

AU - Jensen, Alan J.

AU - Farber, Jeffrey J.

AU - Krusell, Wilbur C.

AU - Raghavan, Srini

AU - Rajhunath, Chilkunda

PY - 1995

Y1 - 1995

N2 - Chemical-Mechanical Planarization (CMP) of SiO2 is performed using alkaline silica slurries while CMP of tungsten (W) utilizes acidic slurries with alumina as the abrasive. Proposed mechanisms for the two CMP processes, with more emphasis on SiO2-CMP, have been discussed in literature. However, much less is known about the removal mechanism of residual slurry particles from the planarized surfaces - a crucial step for subsequent device processing. We discuss the chemical and physical basis of post-CMP cleaning by double-side scrubbing using polyvinyl alcohol (PVA) brushes and show how the interactions between the wafer surface, slurry, and the brush material affect the overall cleaning efficiency. Using the zeta potential concept the common features for cleaning surfaces after SiO2-CMP and W-CMP are established and the differences between these two systems are highlighted. We present surface particle levels for two model systems as a function of cleaning chemistries and discuss their influence on post-CMP surface metal levels.

AB - Chemical-Mechanical Planarization (CMP) of SiO2 is performed using alkaline silica slurries while CMP of tungsten (W) utilizes acidic slurries with alumina as the abrasive. Proposed mechanisms for the two CMP processes, with more emphasis on SiO2-CMP, have been discussed in literature. However, much less is known about the removal mechanism of residual slurry particles from the planarized surfaces - a crucial step for subsequent device processing. We discuss the chemical and physical basis of post-CMP cleaning by double-side scrubbing using polyvinyl alcohol (PVA) brushes and show how the interactions between the wafer surface, slurry, and the brush material affect the overall cleaning efficiency. Using the zeta potential concept the common features for cleaning surfaces after SiO2-CMP and W-CMP are established and the differences between these two systems are highlighted. We present surface particle levels for two model systems as a function of cleaning chemistries and discuss their influence on post-CMP surface metal levels.

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AN - SCOPUS:0029478443

SN - 0272-9172

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JO - Materials Research Society Symposium - Proceedings

JF - Materials Research Society Symposium - Proceedings

Y2 - 17 April 1995 through 21 April 1995

ER -

Post-CMP cleaning of W and SiO₂: a model study

Abstract

ASJC Scopus subject areas

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