Diamond disc pad conditioning in chemical mechanical planarization (CMP): A surface element method to predict pad surface shape

2012 ◽  
Vol 36 (2) ◽  
pp. 356-363 ◽  
Author(s):  
Z.C. Li ◽  
Emmanuel A. Baisie ◽  
X.H. Zhang
Keyword(s):  
Chemical Mechanical Planarization ◽  
Surface Shape ◽  
Surface Element ◽  
Pad Conditioning ◽  
Diamond Disc ◽  
Element Method

Diamond Disc Pad Conditioning in Chemical Mechanical Planarization (CMP): A Mathematical Model to Predict Pad Surface Shape

2011 ◽  
Author(s):  
Z. C. Li ◽  
Emmanuel A. Baisie ◽  
X. H. Zhang
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Chemical Mechanical Planarization ◽  
Mathematic Model ◽  
Surface Shape ◽  
Surface Element ◽  
Wafer Surface ◽  
Polishing Pad ◽  
Pad Conditioning ◽  
Diamond Disc

Chemical mechanical planarization (CMP) is widely used to planarize semiconductor wafers and smooth the wafer surface. In CMP, a diamond disc conditioner is used to condition (or dress) a polishing pad to restore the pad performance. In this paper, a surface element method is proposed to develop a mathematic model to predict the pad surface shape resulted from diamond disc conditioning. The developed model is then validated by published experimental data. Results show that the model is effective to simulate the diamond disc conditioning process and predict the pad surface shape.

Simulation of Diamond Disc Conditioning in Chemical Mechanical Polishing: Effects of Conditioning Parameters on Pad Surface Shape

2010 ◽  
Author(s):  
Emmanuel A. Baisie ◽  
Z. C. Li ◽  
X. H. Zhang
Keyword(s):  
Chemical Mechanical Polishing ◽  
Mathematic Model ◽  
Mechanical Polishing ◽  
Surface Shape ◽  
Surface Element ◽  
Thickness Variation ◽  
Total Thickness ◽  
Rotating Speed ◽  
Total Thickness Variation ◽  
Diamond Disc

Diamond disc conditioning is traditionally employed to restore pad planarity and surface roughness in chemical mechanical polishing (CMP). In this paper, a mathematic model is developed by using a surface element method to simulate and predict the pad surface shape resulted from diamond disc conditioning. The developed model is then validated by published experimental data. Three metrics (total thickness variation (TTV), bow and non-uniformity (NU)) are defined and utilized to evaluate the pad surface shape. Based upon the validated model, effects of conditioning parameters (including sweeping profile, pad rotating speed, conditioner rotating speed, and conditioner diameter) on the pad surface shape are further investigated and discussed.

Finite Element Modeling of Pad Deformation due to Diamond Disc Conditioning in Chemical Mechanical Polishing (CMP)

2012 ◽  
Author(s):  
Emmanuel A. Baisie ◽  
Z. C. Li ◽  
X. H. Zhang
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Material Removal ◽  
High Performance ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Element Analysis ◽  
Fea Model ◽  
Pad Wear ◽  
Diamond Disc

Chemical mechanical planarization (CMP) is widely used to planarize and smooth the surface of semiconductor wafers. In CMP, diamond disc conditioning is traditionally employed to restore pad planarity and surface asperity. Pad deformation which occurs during conditioning affects the material removal mechanism of CMP since pad shape, stress and strain are related to cut rate during conditioning, pad wear rate and wafer material removal rate (MRR) during polishing. Available reports concerning the effect of diamond disc conditioning on pad deformation are based on simplified models of the pad and do not consider its microstructure. In this study, a two-dimensional (2-D) finite element analysis (FEA) model is proposed to analyze the interaction between the diamond disc conditioner and the polishing pad. To enhance modeling fidelity, image processing is utilized to characterize the morphological and mechanical properties of the pad. An FEA model of the characterized pad is developed and utilized to study the effects of process parameters (conditioning pressure and pad stiffness) on pad deformation. The study reveals that understanding the morphological and mechanical properties of CMP pads is important to the design of high performance pads.

scholarly journals Finite Element Analysis of Square Aquifers Containing Pumped Wells and Comparison with Finite Difference Method

1983 ◽  
Vol 14 (2) ◽  
pp. 85-92 ◽  
Author(s):  
Tilahun Aberra
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Difference ◽  
Discrete Time ◽  
Surface Element ◽  
Dimensionless Time ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Wide Range ◽  
Element Method

The numerical solution of the behaviour of discrete time steps in digital computer analysis of square aquifers containing pumped wells is examined by using the finite element method with a 4 node linear quadrilateral isoparametric surface element. A wide range of time steps are used in the computation. The calculations show that discrete time steps can cause errors and oscillations in the calculations particularly when wells start and stop pumping. Comparison with known results obtained by theoretical and finite difference procedures has been considered. The main objective of this paper is to demonstrate comparison of the finite element and finite difference simulation results over a regular linear 4 node quadrilateral mesh suitable to represent the two numerical schemes with a marked similarity. The dimensionless time drawdown results of the finite element method agreed well with the finite difference and analytical results for small time increment. However, for large time increments, there are from slight to significant oscillations in the results and notable discrepancies are observed in the solutions of the two numerical methods.

A Study on the Self-Stopping CMP Process for the Planarization of the High Step Height(@step height>1.5um) Pattern

2004 ◽  
Vol 816 ◽  
Author(s):  
Kwang-Bok Kim ◽  
Hyo-Jin Lee ◽  
Ki-Hoon Jang ◽  
Joung-Duk Ko ◽  
Kyung-Hyun Kim ◽  
...  
Keyword(s):  
Chemical Mechanical Planarization ◽  
Step Height ◽  
Design Rule ◽  
Planarization Process ◽  
Series Of Experiments ◽  
Semiconductor Fabrication ◽  
Pad Conditioning ◽  
Height Step ◽  
High Degree ◽  
Polishing Pressure

AbstractCMP(Chemical Mechanical Planarization) process is widely used to reduce step height in semiconductor fabrication processes. As a design rule shrinks, a highly planar surface becomes inevitable within wafer scales. In order to get a high degree of a planarization, self-stopping characteristics of a ceria-based slurry should be studied and used in semiconductor process. In this study, threshold polishing pressure for a self-stopping characteristics was obtained by optimizing down pressure, pad conditioning, and mixing ratio of ceria abrasive and additive. A series of experiments were made to optimize the threshold polishing pressure in variable line & space patterns that consist of 0.8um step height and unit oxide film. As a result, self-stopping cmp process is twice batter than conventional silica-based process with respect to planarity and WIWNU. In addition, WIWNU and step height was dramatically decreased to less than 1000Å when applying to real fabrication devices over 2um step height.

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