Integrating Modeling Of Chemical Mechanical Planarization For Sub-Micron IC Fabrication

by Luo, Jianfeng; Dornfeld, David

• ISBN13: 9783540223696
• ISBN10: 354022369X
• Format: Hardcover
• Copyright: 2004-12-31
• Publisher: Springer Verlag

Summary

This book is the product of a developing research focus on CMP at Berkeley. Its focus is on the important area of process models which have not kept pace with the tremendous expansion of applications of CMP. It specifically deals with the development of models with sufficient detail to allow the evaluation and tradeoff of process inputs and parameters to assess impact on quality or quantity of production. The important role of the mechanical elements of the process are included in such an "integrated model". The objective of the book is to introduce some background on the overlooked mechanical aspects of the process - including pad surface topography and abrasive particles. The "integrated model" can be particularly useful as one looks towards optimization of the process, design of consumables and, importantly, looking to minimize the environmental affects of CMP.

Table of Contents

Introduction	1	(14)
Overview	1	(8)
ILD/IMD Planarization	2	(1)
Copper Damascene Process	3	(3)
Shallow Trench Isolation	6	(1)
CMP Input and Output Parameters	7	(2)
Structure of the Book	9	(3)
Review of CMP Modeling	9	(1)
Particle-Scale Modeling	10	(1)
Feature- and Die-Scale Modeling	11	(1)
Wafer-Scale Modeling	12	(1)
References	12	(3)
Review of CMP Modeling	15	(38)
Introduction	15	(2)
Particle-Scale Models	17	(15)
Models Considering Slurry Particle-Wafer Surface Interactions	18	(4)
Models Considering Polishing Pad-Wafer Surface Interactions	22	(1)
Models Considering Slurry Particle-Polishing Pad Interactions	23	(2)
Models Considering Slurry Chemical-Wafer Interactions	25	(2)
Models Considering Slurry Chemical-Slurry Particle Interactions and Slurry Chemical-Polishing Pad Interactions	27	(1)
Comprehensive Models Considering Interactions among Polishing Pad, Slurry Particles, Slurry Chemicals and Wafer Surface	28	(2)
Summary of Particle-Scale Models	30	(2)
Feature- and Die-Scale Models	32	(9)
Semi-Empirical Models	32	(6)
Physical Models	38	(1)
Electronics Computer Aided Design	39	(2)
Wafer-Scale Models	41	(2)
Pressure Distribution Models Based on Solid-Solid Contact	41	(1)
Pressure Distribution Models Based on Semi-Solid-Solid Contact and Solid-Fluid-Solid Contact	42	(1)
Discussions and Concluding Remarks	43	(1)
References	44	(9)
Material Removal Mechanism in CMP: A Comprehensive Model of Abrasive Particle, Pad Asperity and Wafer Interactions	53	(44)
Introduction	53	(3)
Solid-Solid Contact Mode in CMP	56	(3)
Assumptions for Model Development	59	(12)
Periodic Roughness of Pad Surface	61	(2)
Plastic Deformations Over Wafer-Particle and Pad-Particle Interfaces	63	(4)
Normal Distribution of Abrasive Particle Size	67	(4)
Formulations of Material Removal Rate	71	(4)
Model Verification	75	(14)
An Estimation of Material Removal Rate	75	(5)
Down Pressure Dependency of MRR	80	(9)
Discussion	89	(1)
Conclusion	90	(2)
References	92	(5)
Effects of Abrasive Size Distribution in CMP	97	(18)
Introduction	97	(1)
Detailed View of Wafer-Abrasive-Pad Contact and Material Removal Rate as a Function of Abrasive Size Distribution	98	(7)
Experimental Verification	105	(6)
Discussions on Standard Deviation	111	(1)
Conclusion	111	(1)
References	112	(3)
Material Removal Regions in CMP: Coupling Effects of Slurry Chemicals, Abrasive Particle Size Distribution and Wafer-Pad Contact Area	115	(32)
Introduction	115	(2)
Transition from the First Region to the Second Region: Effects of Bi-layer Property of the Passive Film	117	(10)
Transition from the Second Region to the Third Region: Effects of Abrasive Size Distribution and Wafer-Pad Contact Area	127	(5)
Experimental Verification	132	(9)
Two Transitions	132	(5)
Coupling Effects of Abrasive Sizes, Polishing Pad and Chemicals on Down Pressure Dependency of MRR	137	(4)
Conclusion	141	(1)
References	142	(5)
One and Semi-Two Dimensional Feature-and Die-Scale Modeling for the Damascene Process	147	(90)
Introduction	147	(4)
Framework of Topography Evolution Model	151	(1)
Definition of Model Parameters	152	(7)
Feature-Scale Wafer Topography	152	(1)
Die-Scale Wafer Topography	153	(1)
Pad Material Properties	154	(4)
Material Removal Properties	158	(1)
Modeling of Wafer-Pad Contact at the Feature-Scale	159	(7)
Linear Elastic Pad Assumption	159	(5)
Linear Viscoelastic Pad Assumption	164	(2)
Modeling of Wafer-Pad Contact at the Die-Scale	166	(1)
Analytical Solution Assuming Die-Scale Pressure Independent of Polishing Time	167	(9)
Linear Elastic Pad Assumption	168	(3)
Linear Viscoelastic Pad Assumption	171	(5)
Line Width Dependency of Topography Evolution	176	(8)
Two-Dimensional Boundary Element Model of Pad Asperity Layer Deformation	177	(1)
Two-Dimensional Contact Mechanics Model of Pad Asperity Layer Deformation	178	(2)
Influences of Pad Asperity Layer Thickness	180	(2)
Effective Stiffness of Pad Asperity Layer	182	(2)
Simulation vs. Experimental Results	184	(36)
Transition of Three Stages	186	(7)
Oxide Erosion as a Function of Pattern Density and Line Width	193	(2)
Oxide Erosion as a Function of Time	195	(2)
Dishing as a Function of Pattern Density and Line Width	197	(3)
Effects of Oxide and Copper Removal Mechanism on Erosion and Dishing	200	(4)
Effects of Pad Properties on Erosion and Dishing	204	(2)
Effects of Pressure on Dishing and Erosion	206	(8)
Vertical Directional Die-Feature Scale Integration	214	(3)
Summary of Simulation Results	217	(3)
Model Limitations and Extensions	220	(11)
Model Considering Barrier Layer	220	(1)
Feature-Scale Model for Standard-Cell (Hierarchical) Layouts	220	(1)
Lateral Directional Die-Feature Scale Integration	220	(9)
Dummy Filling	229	(2)
Conclusion	231	(1)
References	232	(5)
Three-Dimensional Feature-Scale Modeling of CMP	237	(18)
Introduction	237	(1)
Contact Mechanics Based Governing Equation	238	(1)
Numerical Solution of the Governing Equations	238	(6)
Constant Element	240	(2)
Quadratic Element	242	(2)
Boundary Conditions in CMP	244	(1)
Displacement Condition	244	(1)
Pressure Condition	245	(1)
Topography Evolution	245	(1)
Simulation Example	246	(5)
Conclusion and Future Work	251	(3)
References	254	(1)
Wafer-Scale Modeling of CMP	255	(30)
Introduction	255	(2)
CMP Configurations and Velocity Distribution	257	(4)
Pressure Distribution	261	(16)
Solid-Solid Contact	261	(8)
Solid-Fluid-Solid Contact	269	(8)
Air Pressure Distribution over the Platen-Belt Interface in the Linear Type Machine	277	(1)
Optimization of WIWNU from the Viewpoint of Consumable Effects	277	(3)
Feature-Die-Wafer Scale Integration	280	(2)
Conclusion	282	(1)
References	283	(2)
Summary and Future Work	285	(12)
Summary	285	(2)
Particle-Scale Modeling	285	(2)
Feature-and Die-Scale Modeling	287	(1)
Wafer-Scale Modeling	287	(1)
Future Work	287	(8)
Further Development and Calibration of the Particle-Scale Model	288	(1)
`Swarm' Simulation	288	(1)
Interconnect Modeling for EDA	289	(1)
Systematic Design and Micro-Fabrication of CMP Consumables	290	(1)
Green CMP	290	(5)
References	295	(2)
A BOUNDARY ELEMENT METHOD	297	(12)
Introduction	297	(1)
Governing Differential Equation of Elastostatics	298	(1)
Betti's Reciprocal Theorem and Kelvin's Solution	298	(2)
Boundary Integral Equation	300	(1)
Numerical Formulation of Boundary Integral Equation	301	(4)
System Equations	305	(1)
BEM vs. FEM	306	(1)
References	307	(2)
Index	309