Dynamics of the Formation of the Subambient Pressure Distribution During Chemical-Mechanical Polishing

2007 ◽  
Author(s):  
A. Osorno ◽  
S. Tereshko ◽  
I. Yoon ◽  
S. Danyluk
Keyword(s):  
Integrated Circuits ◽  
Pressure Distribution ◽  
Chemical Mechanical Polishing ◽  
Rotational Speed ◽  
Silicon Wafers ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Abrasive Particles ◽  
Pressure Distributions ◽  
Time Period

Chemical-Mechanical Polishing is used to polish silicon wafers in the manufacturing of integrated circuits. Wafers are pressed, electronics side down, onto a rotating pad that is flooded with a slurry containing abrasive particles. The slurry is entrained in the interface and the abrasive particles slide against the silicon and polish it. Our previous work has shown that subambient pressures develop at the silicon/pad interface and we have measured this pressure and its distribution over the wafer surface (1). However, our experiments have been limited to those conditions where the pad rotates and the wafer slides on the pad but the wafer itself does not rotate. Our experiments showed a skewed pressure distribution. This paper describes experiments and pressure distribution measurements where the wafer, as well as the pad/platen is rotated (2). Specifically-designed wireless electronic transmitters and receivers were built and used to measure the interfacial pressures at the silicon/pad interface. Subambient stress maps and temperatures have been measured and Figure 1 shows an example of a skewed pressure distribution when the silicon is not rotated and Figure 2 shows the pressure distribution for the same wafer while it is rotating. The subambient pressures develop over a 2 second time period from when the rotation started. The pressure distributions are symmetric in spite of the lean and tilt of the wafers. The rotational speed and other variables have a big influence on the polishing rate and this will be discussed in the talk.

Analysis on the Contact Pressure Distribution of Chemical Mechanical Polishing by the Bionic Polishing Pad with Phyllotactic Pattern

2011 ◽  
Vol 215 ◽  
pp. 217-222 ◽  
Author(s):  
Y.S. Lv ◽  
Nan Li ◽  
Jun Wang ◽  
Tian Zhang ◽  
Min Duan ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Chemical Mechanical Polishing ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Boundary Edge ◽  
Contact Pressure Distribution ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Polishing Pad

In order to make the contact pressure distribution of polishing wafer surface more uniform during chemical mechanical polishing (CMP), a kind of the bionic polishing pad with sunflower seed pattern has been designed based on phyllotaxis theory, and the contact model and boundary condition of CMP have been established. Using finite element analysis, the contact pressure distributions between the polishing pad and wafer have been obtained when polishing silicon wafer and the effects of the phyllotactic parameter of polishing pad on the contact pressure distribution are found. The results show that the uniformity of the contact pressure distribution can be improved and the singularity of the contact pressure in the boundary edge of polished wafer can be decreased when the reasonable phyllotactic parameters are selected.

A Material Removal Rate Model Considering Interfacial Micro-Contact Wear Behavior for Chemical Mechanical Polishing

2005 ◽  
Vol 127 (1) ◽  
pp. 190-197 ◽  
Author(s):  
Yeau-Ren Jeng ◽  
Pay-Yau Huang
Keyword(s):  
Material Removal Rate ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Surface Hardness ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Rate Model ◽  
Abrasive Particles ◽  
Material Removal Rate Model

Chemical Mechanical Polishing (CMP) is a highly effective technique for planarizing wafer surfaces. Consequently, considerable research has been conducted into its associated material removal mechanisms. The present study proposes a CMP material removal rate model based upon a micro-contact model which considers the effects of the abrasive particles located between the polishing interfaces, thereby the down force applied on the wafer is carried both by the deformation of the polishing pad asperities and by the penetration of the abrasive particles. It is shown that the current theoretical results are in good agreement with the experimental data published previously. In addition to such operational parameters as the applied down force, the present study also considers consumable parameters rarely investigated by previous models based on the Preston equation, including wafer surface hardness, slurry particle size, and slurry concentration. This study also provides physical insights into the interfacial phenomena not discussed by previous models, which ignored the effects of abrasive particles between the polishing interfaces during force balancing.

The Effect of Microstructure on Chemical Mechanical Polishing Process of Thin-Film Metals

2007 ◽  
Author(s):  
Joseph Bonivel ◽  
Sarah Biltz ◽  
Elon Terrell ◽  
Burak Ozdoganlar ◽  
C. Fred Higgs
Keyword(s):  
Thin Film ◽  
Integrated Circuits ◽  
Data Storage ◽  
Chemical Mechanical Polishing ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Metal Thin Films ◽  
Storage Devices ◽  
Multi Scale ◽  
Chemical Mechanical Polishing Process

Chemical mechanical polishing (CMP) is a critical nanomanufacturing process used to remove or planarize ultrathin metallic, dielectric, or barrier layers on silicon wafers. The CMP process is a vital interim fabrication step for integrated circuits and data storage devices. One of the major shortcomings of existing CMP models is that they do not account for crystallographic effects of the thin film metal materials when predicting material removal rates. This work investigates the effect of the microstructure on the CMP of copper and metal thin films on silicon wafer. Nanoindentation tests were conducted to measure the hardness variations across a wafer surface due to the crystallography of the metal films. Spatial variation of mechanical properties was also input into an existing multi-scale CMP model. Nano-characterization and CMP experimental results are presented and compared to an existing CMP wear model.

An Economic Study on Chemical Mechanical Polishing of Silicon Wafers

2009 ◽  
Author(s):  
Emmanuel A. Baisie ◽  
Man Yang ◽  
Ravindra Kaware ◽  
Maria Hooker ◽  
Z. C. Li ◽  
...  
Keyword(s):  
Chemical Mechanical Polishing ◽  
Cost Model ◽  
Labor Cost ◽  
Silicon Wafers ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Variable Cost ◽  
Fixed Cost ◽  
Economic Study ◽  
Total Cost

Chemical mechanical polishing (CMP) is used to remove irregularities on the silicon wafer surface. The importance of CMP is the achievement of both local and global planarity of wafer surface. This paper presents an economic study on CMP of silicon wafers. A cost model is developed to predict the total cost for CMP of silicon wafers. An input-output model is developed to analyze parameters relevant to the fixed cost and variable cost. The labor cost is investigated through a flow chart of the labor operation. Based on the cost model, a hypothetical case study is conducted to show the model’s capability of performing sensitivity analysis and identifying critical factors for the total cost for strategic management purposes.

A Material Removal Rate Model Considering Interfacial Micro-Contact Wear Behavior for Chemical Mechanical Polishing

2005 ◽  
Author(s):  
Yeau-Ren Jeng ◽  
Pay-Yau Huang
Keyword(s):  
Material Removal Rate ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Surface Hardness ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Rate Model ◽  
Abrasive Particles ◽  
Material Removal Rate Model

Chemical Mechanical Polishing (CMP) is a highly effective technique for planarizing wafer surfaces. Consequently, considerable research has been conducted into its associated material removal mechanisms. The present study proposes a CMP material removal rate model based upon a micro-contact model which considers the effects of the abrasive particles located between the polishing interfaces, thereby the down force applied on the wafer is carried both by the deformation of the polishing pad asperities and by the penetration of the abrasive particles. It is shown that the current theoretical results are in good agreement with the experimental data published previously. In addition to such operational parameters as the applied down force, the present study also considers consumable parameters rarely investigated by previous models based on the Preston equation, including wafer surface hardness, slurry particle size, and slurry concentration. This study also provides physical insights into the interfacial phenomena not discussed by previous models, which ignored the effects of abrasive particles between the polishing interfaces during force balancing.

Measurement Methods of Pad Properties for Chemical Mechanical Polishing

2007 ◽  
Author(s):  
X. H. Zhang ◽  
Z. J. Pei ◽  
Graham R. Fisher
Keyword(s):  
Integrated Circuits ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Building Blocks ◽  
Measurement Methods ◽  
Silicon Wafers ◽  
Mechanical Polishing ◽  
Increasing Demand ◽  
Polishing Pads ◽  
Wafer Surfaces

Silicon wafers are the fundamental building blocks for most integrated circuits. Chemical mechanical polishing is used to manufacture silicon wafers as the final material removal process to meet the ever-increasing demand for flatter wafers and lower prices. The polishing pad is one of the critical factors in planarizing wafer surfaces and its properties play critical roles in polishing. However, pad properties change during the process. This paper reviews the measurement methods for thickness, hardness, and Young’s modulus of polishing pads.

A Modeling Approach for Predicting the Abrasive Particle Motion During Chemical Mechanical Polishing

2007 ◽  
Vol 129 (4) ◽  
pp. 933-941 ◽  
Author(s):  
Elon J. Terrell ◽  
C. Fred Higgs III
Keyword(s):  
Particle Motion ◽  
Chemical Mechanical Polishing ◽  
Manufacturing Process ◽  
Material Removal ◽  
Abrasive Particle ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Shear Cell ◽  
Abrasive Particles ◽  
Simulation Results

Chemical mechanical polishing (CMP) is a manufacturing process in which a wafer surface is polished by pressing it against a rotating pad that is flooded with slurry. The slurry itself is a fluid containing abrasive particles. Past experimentation has shown that the distribution of suspended particles in the slurry is significantly related to the distribution of material removal on the wafer during CMP. Therefore, this study involves the development and simulation of a model that predicts the kinematics and trajectory of the abrasive particles. The simulation results compare well to data from shear cell experiments data conducted by other researchers.

Coffee Stain Ring Effect and Nonuniform Material Removal in Chemical Mechanical Polishing

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Jianguo Xin
Keyword(s):  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Abrasive Particles ◽  
Patterned Wafers ◽  
Microfluidic Flow ◽  
Slurry Layer ◽  
Nonuniform Material ◽  
Ring Effect

When a drop of coffee dries on the counter-top, it leaves a dense, ringlike stain along its perimeter. Solids immersed in a drying drop will migrate toward the edge of the drop and form a solid ring. Such phenomena create ringlike stains and happen for a wide variety of surfaces, solvents, and solutes. It is referred to as the coffee stain ring effect. The phenomenon is caused by the outward microfluidic flow of the solute within the drop, which is driven by the evaporation of solvent. We show that the mechanism for the ring effect contributes to the nonuniform material removal in chemical mechanical polishing (CMP), specifically, at edges of blanket wafers causing the edge effect or at edges and corners of protrusive features on patterned wafers inducing the doming effect; metal dishing and dielectric erosion. By controlling the evaporation profile of the solvent in the slurry layer between the wafer surface and the polishing pad, such as making grooves or embedding the abrasive particles on the pad, or delivering the slurry from the bottom of the pad, one can improve the uniformity of material removal during the CMP process.

Chemical Mechanical Polishing of Silicon Wafers: Finite Element Analysis of Wafer Flatness

2005 ◽  
Author(s):  
X. H. Zhang ◽  
Z. J. Pei ◽  
Graham R. Fisher
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Integrated Circuits ◽  
Chemical Mechanical Polishing ◽  
Silicon Wafers ◽  
Mechanical Polishing ◽  
High Quality ◽  
Element Analysis ◽  
Polishing Pressure

Silicon is the primary semiconductor material used to fabricate integrated circuits. The quality of microchips depends directly on the quality of silicon wafers. A series of processes are required to manufacture the high-quality silicon wafers. Chemical mechanical polishing is a necessary step to achieve the required wafer flatness. In this paper, a finite element analysis has been conducted to study the effects of influencing factors (including Young’s modulus and Poisson’s ratio of the polishing pad, thickness of the pad, and polishing pressure) on the wafer flatness.

scholarly journals INVESTIGATION OF ULTRA-THIN SILICON WAFERS STRENGTH DEPENDING ON WAFER MATERIAL GROWING METHODS AND SURFACE TREATMENT

2020 ◽  
Author(s):  
Andrei Averkin ◽  
Vladimir Kozlov ◽  
Vladimir Nikolaev ◽  
Roman Timashov ◽  
Maxim Fyodorov ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Surface Treatment ◽  
Chemical Mechanical Polishing ◽  
Surface Preparation ◽  
Silicon Wafers ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Thin Silicon ◽  
Diamond Paste

The mechanical strength of ultra-thin 100 μm Si wafers was measured depending on Si growing methods and machining modes of wafer surface preparation (abrasive grinding, diamond paste polishing, chemical-mechanical polishing — CMP)

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