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Application of Elastohydrodynamic Lubrication to simulation of Chemical Mechanical Polishing

Abstract
This paper proposes a model that integrates the microscale asperity contact and macroscale elastohydrodynamic lubrication (EHL) to simulate the pressure distribution in the chemical mechanical planarization (CMP). This model involves modified Reynolds equation used to describe the status of fluid field, the equation of the average asperity contact pressure by using statistics for solid contact pressure due to asperity contact, and the equation of the elastic pad deformation in bulk. Results show that with increasing relative velocity or load, the magnitude of the sub-ambient pressure decreases, the greater asperity contact pressure is formed to support the load, and the friction force also increases to cause the greater rotation angles. The magnitude of the fluid pressure is of the same order of magnitude as the applied normal load. Therefore, the addition of this fluid pressure may significantly change the distribution of the contact stress. The reason of the sub-ambient pressure existed is the deformation of the pad. In the material removal rate model, the elastic deformation of asperities is assumed, and the contact pressure is determined by Hooke¡¦s law. The indentation depth can be obtained from the force balance imposed on the particles by the wafer and the pad. Results show that the material removal rate decreases with increasing abrasive size, due to the increasing contact area between the abrasive and wafer.
Keywords¡GElastohydrodynamic Lubrication, Chemical Mechanical Polishing

Identiferoai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0823106-135022
Date23 August 2006
CreatorsLiu, Chun-Hsiang
ContributorsYuang-Cherng Chiou, Y.R. Jeng, Jen-Fin Lin, Rong-Tsong Lee
PublisherNSYSU
Source SetsNSYSU Electronic Thesis and Dissertation Archive
LanguageCholon
Detected LanguageEnglish
Typetext
Formatapplication/pdf
Sourcehttp://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0823106-135022
Rightsrestricted, Copyright information available at source archive

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