Inferences of Slurry Bow Wave Width from Mean Coefficient of Friction and Directivity in Chemical Mechanical Planarization

2018 ◽  
Vol 8 (5) ◽  
pp. P3018-P3021 ◽  
Author(s):  
Gabriela Diaz ◽  
Yasa Sampurno ◽  
Siannie Theng ◽  
Ara Philipossian
Keyword(s):  
Coefficient Of Friction ◽  
Chemical Mechanical Planarization ◽  
Bow Wave

In Situ Temperature Measurement During Oxide Chemical Mechanical Planarization

2003 ◽  
Vol 767 ◽  
Author(s):  
Jesse Cornely ◽  
Chris Rogers ◽  
Vincent Manno ◽  
Ara Philipossian
Keyword(s):  
Friction Force ◽  
Imaging System ◽  
Chemical Mechanical Planarization ◽  
Infrared Camera ◽  
Linear Velocity ◽  
Dual Emission ◽  
Bow Wave ◽  
Pad Conditioning ◽  
Force Data

AbstractThis paper presents temperature and friction force data at the pad-slurry-wafer interface during real time CMP polishing with in situ pad conditioning. Experiments are performed on a 1:2 scale laboratory tabletop rotary polisher with variable pad speed and wafer down force control. Dual emission laser induced fluorescence (DELIF) techniques are used to optically measure the temperature directly beneath the wafer during polishing using a two camera imaging system. An infrared camera and a thermocouple are alternately used to measure bow wave temperatures. Optically transparent BK-7 glass wafers with either concave (wafer edges sloping toward the pad) or convex (wafer edges sloping away from the pad) curvature were used. When concave wafers are polished, the bow wave temperatures are 3°C to 5°C higher than the corresponding value for convex wafers. Similarly, slurry temperatures under the concave wafers are 5°C to 6°C higher than the value for convex wafers (±0.5°C). The friction force per unit area is typically 2 kPa to 3 kPa higher for concave wafers. Temperatures beneath the wafer are as high as 12°C above the ambient temperature for a concave wafer at a high applied wafer pressure (41.4 kPa) or linear velocity (0.93 m/sec). Bow wave temperatures reach as high as 9°C above ambient at a linear velocity of 0.93 m/sec. The lowest temperatures, within 1°C of ambient at the bow wave and 5°C above ambient under the wafer, were found with convex wafers at low applied wafer pressures (20.7 kPa). Linear velocity has little effect on the slurry temperature while polishing convex wafers. Increasing slurry abrasive concentration causes an increase in temperature, despite a decrease in friction force. A correlation, with an R-squared value greater than 0.96, exists between the bow wave temperature and the temperature beneath the wafer. This correlation holds at constant linear velocities across wafer shapes, applied wafer pressures, and slurry concentrations.

scholarly journals Effect of Retaining Ring Slot Designs, Conditioning Discs and Conditioning Schemes on the Slurry Bow Wave Width during Chemical Mechanical Planarization

2018 ◽  
Vol 7 (5) ◽  
pp. P253-P259 ◽  
Author(s):  
Leticia Vazquez Bengochea ◽  
Yasa Sampurno ◽  
Calliandra Stuffle ◽  
Fransisca Sudargho ◽  
Ruochen Han ◽  
...  
Keyword(s):  
Chemical Mechanical Planarization ◽  
Bow Wave ◽  
Retaining Ring

scholarly journals Effect of Conditioner Type and Downforce, and Pad Surface Micro-Texture on SiO2 Chemical Mechanical Planarization Performance

Micromachines ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 258 ◽  
Author(s):  
Jeffrey McAllister ◽  
Calliandra Stuffle ◽  
Yasa Sampurno ◽  
Dale Hetherington ◽  
Jon Sierra Suarez ◽  
...  
Keyword(s):  
Coefficient Of Friction ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Polishing Process ◽  
Wafer Polishing ◽  
The Coefficient Of Friction

Based on a previous work where we investigated the effect of conditioner type and downforce on the evolution of pad surface micro-texture during break-in, we have chosen certain break-in conditions to carry out subsequent blanket SiO2 wafer polishing studies. Two different conditioner discs were used in conjunction with up to two different conditioning downforces. For each disc-downforce combination, mini-marathons were run using SiO2 wafers. Prior to polishing, each pad was broken-in for 30 min with one of the conditioner-downforce combinations. The goal of this study was to polish wafers after this break-in to see how the polishing process behaved immediately after break-in. One of the discs used in this study produced similar micro-texture results at both downforces, which echoed the results seen in the mini-marathon. When comparing the different polishing results obtained from breaking-in the pad with the different discs used in this study, the coefficient of friction (COF) and SiO2 removal rate (RR) were uncorrelated in all cases. However, the use of different discs resulted in different COF and RR trends. The uncorrelated COF and RR, as well as the differing trends, were explained by pad micro-texture results (i.e. the differing amount of fractured, poorly supported pad asperity summits).

An Analytical Thermodynamic Approach to Friction of Rubber on Ice

2012 ◽  
Vol 40 (2) ◽  
pp. 124-150
Author(s):  
Klaus Wiese ◽  
Thiemo M. Kessel ◽  
Reinhard Mundl ◽  
Burkhard Wies
Keyword(s):  
Coefficient Of Friction ◽  
Liquid Layer ◽  
Contact Area ◽  
Leading Edge ◽  
Viscous Friction ◽  
Analytical Approximation ◽  
Real Contact Area ◽  
Length Scales ◽  
Real Contact ◽  
Ice Surface

ABSTRACT The presented investigation is motivated by the need for performance improvement in winter tires, based on the idea of innovative “functional” surfaces. Current tread design features focus on macroscopic length scales. The potential of microscopic surface effects for friction on wintery roads has not been considered extensively yet. We limit our considerations to length scales for which rubber is rough, in contrast to a perfectly smooth ice surface. Therefore we assume that the only source of frictional forces is the viscosity of a sheared intermediate thin liquid layer of melted ice. Rubber hysteresis and adhesion effects are considered to be negligible. The height of the liquid layer is driven by an equilibrium between the heat built up by viscous friction, energy consumption for phase transition between ice and water, and heat flow into the cold underlying ice. In addition, the microscopic “squeeze-out” phenomena of melted water resulting from rubber asperities are also taken into consideration. The size and microscopic real contact area of these asperities are derived from roughness parameters of the free rubber surface using Greenwood-Williamson contact theory and compared with the measured real contact area. The derived one-dimensional differential equation for the height of an averaged liquid layer is solved for stationary sliding by a piecewise analytical approximation. The frictional shear forces are deduced and integrated over the whole macroscopic contact area to result in a global coefficient of friction. The boundary condition at the leading edge of the contact area is prescribed by the height of a “quasi-liquid layer,” which already exists on the “free” ice surface. It turns out that this approach meets the measured coefficient of friction in the laboratory. More precisely, the calculated dependencies of the friction coefficient on ice temperature, sliding speed, and contact pressure are confirmed by measurements of a simple rubber block sample on artificial ice in the laboratory.

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