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Particle-surface interactions in chemical mechanical polishing
30. anon. Nanotechnology:
Molecularly
Designed
Materials.
Am Chemical; 1998 Mar. 424 pages. ISBN 0-8412-
3392-8, $114.95. 31. Lynch, Mike. Parametric Programming for Computer Numerical Control Machine Probes: CNC’s Best-Kept Secret. SME; 1996 Nov. 433 pages. ISBN O-87263-481-7, $83.00.
Tools
& Touch
32. Dugger, M. T.; Adkins, C. L. J.; Resnick, P. J.; Jeon, J. S.; Raghavan, S. Particle-surface Interactions In chemical mechanical polishing. Bi-annual lnfemational Symposium On Ultra Clean Processing Of Silicon Surfaces. Albuquerque, NM: Sandia National Labs. 1996; SAND-96-2328C. 6 pages. Material removal in chemical mechanical polishing (CMP) occurs by a pressure accentuated chemical attack of the surface. The polishing slurry typically consists of abrasive particles and reactive chemicals that may or may not include an oxidant. Post-CMP cleaning processes must remove both the ionic contaminants and any remaining polishing slurry particles. Central to the effectiveness of a clean is the use of conditions that will minimize the binding force between the residual particles and the wafer surface. The morphology and composition of the particle, the surface from which it must be removed, and the environment surrounding the wafer will determine the magnitude of forces that hold a particle to the wafer surface. At the SandiaISEMATECH Center for Contamination Free Manufacturing, two techniques-atomic force microscopy (AFM) and electrokinetic deposition-are being used to explore these interactions for CMP of both oxide and tungsten surfaces. A basic understanding of particle-surface interaction forces and how they are affected by the chemical/physical environment of the particle and surface is the objective of this task. Modification of the binding forces between particles and surfaces may be used to maximize post-CMP cleaning effectiveness. P. Z. Penta-prism long trace profiler (PPLTP) for measurement of grazing Denver 96. Upton, NY: Brookhaven National Lab. 1996 May; BNL-62826. 8 pages, The Long Trace Profiler (LTP) is in use at a number of locations throughout the world for the measurement of the figure and mid frequency roughness of x-ray mirrors. The standard configuration requires that the surface tested lie in a horizontal plane as the optical head is scanned along a horizontal line. For applications where gravity-induced sag of the surface cannot be tolerated, such as in x-ray telescope mirror metrology, it is desirable to measure the mirror as it is mounted in a vertical configuration. By making simple modifications to the standard LTP system, we have demonstrated that it is possible to use the LTP principle to measure the surface of x- ray mirrors and mandrels mounted in the vertical orientation. The major change in the LTP system is the use of a penta prism on a vertical translation stage to direct the probe beam onto the surface and the addition of a precision rotation stage to hold the test object. A 3-D map of the surface topography of the complete cylindrical asphere can be generated quite easily with this technique. Measurements with a prototype system indicate a slope error accuracy of better than 1 microradian is possible, with a figure error repeatability of better than 50 nm. 19 refs., 4 figs. 33. Qian, S.; Li, H.; Takacs,
incidence
space
optics.
34. Spanner, K.; Wolny, W. W.; Lula, B. Plezo actuators move in the nanometer regime. Laser focus World 1996 Nov; 32(11): 6. Lead zirconate titanate (PZT) piezoelectric actuators and motors, coupled with recent advances in piezoelectric materials, controls and testing technology, allow accurate and repeatable motion for measurements in the nanometer range. Enabling technologies like active vibration cancellation and active error compensation improve precision positioning and control. Smart PZT actuators that use coded components and intelligent control electronics, or are integrated with sensor and controller allow system autocalibration. New ways to produce piezoceramics that can meet the piezoelectric, dielectric and mechanical properties required by dynamic actuator applications are also available. Nam, Soo-Ryong. Piezoelectrically driven micro-positioning system for the ductile-mode materials. Journal of Materials Processing Technology. 1996 Sep; 61(3): 309-319. The mirror-like grinding of brittle materials is required in many precision engineering areas. Ductile-mode grinding, a new grinding technology for brittle materials, is considered as a solution of this difficult-to-cut materials grinding. It is known that the fracture mechanism of brittle materials changes to plastic deformation when extremely small depths of grinding or removal rates are employed. In this paper, ductile-mode grinding experiments has been performed using a micro-positioning grinding table that does not require a position sensor, but uses piezoelectric voltage feedback. With hysteresis-considering reference input, it has a sub-micrometer order of displacement resolution. It is established that the characteristics of the ground surfaces change to those associated with plastic deformation for small depths of grinding. 12 Refs.
35. Kim, Jeong-Du;
grinding
of brittle
36. Zhang, L.; Mahdi, M. Plastic behavior of silicon subjected to micro-indentation. Journal of Materials Science. 1996 Nov; 31(21): 5671-5676. Micro-indentation is widely used in evaluating the mechanical properties of ceramics. It is also an important measure in the study of machinability of brittle materials. Because of the complexity of interaction in the vicinity of the contact zone between the indenter and work material, an analytical or experimental method is unable to predict the detailed evolution process of deformation. With the aid of the finite element method, this paper analyses the behavior of a silicon subjected to micro-indentation by a spherical indenter. The development of stress fields was thoroughly simulated. A constitutive relationship was confirmed based on a comparison with experimental observations. This study offers essential information for the indentation of ceramics and a deeper understanding of material removal mechanisms in machining brittle materials. 14 Refs. 37. Bulsara, Vispi H.; Ahn, Yoomin; Chandrasekar, Srinivasan; Farris, Thomas N. Polishing and lapping temperatures. ASMEZSTLE Joint Ttibology Conference; 1996. New York, NY: American Society of Mechanical Engineers; 1996. 8 pages. Polishing is a finishing process in which a smooth work surface is produced by rubbing it against a polishing block with an abrasive slurry interspersed between them. A model has been developed to estimate the temperature rise of the work surface in polishing. In this model, the forces acting on an abrasive particle are derived from a mechanistic analysis of abrasiveworkpiece contacts. The heat generated at a contact is taken as the product of the friction force and the relative sliding velocity between the abrasive and the work surface. For calculating the heat flux transferred into the workpiece, each of the PRECISION
ENGINEERING
149
Molecularly
Designed
Materials.
Am Chemical; 1998 Mar. 424 pages. ISBN 0-8412-
3392-8, $114.95. 31. Lynch, Mike. Parametric Programming for Computer Numerical Control Machine Probes: CNC’s Best-Kept Secret. SME; 1996 Nov. 433 pages. ISBN O-87263-481-7, $83.00.
Tools
& Touch
32. Dugger, M. T.; Adkins, C. L. J.; Resnick, P. J.; Jeon, J. S.; Raghavan, S. Particle-surface Interactions In chemical mechanical polishing. Bi-annual lnfemational Symposium On Ultra Clean Processing Of Silicon Surfaces. Albuquerque, NM: Sandia National Labs. 1996; SAND-96-2328C. 6 pages. Material removal in chemical mechanical polishing (CMP) occurs by a pressure accentuated chemical attack of the surface. The polishing slurry typically consists of abrasive particles and reactive chemicals that may or may not include an oxidant. Post-CMP cleaning processes must remove both the ionic contaminants and any remaining polishing slurry particles. Central to the effectiveness of a clean is the use of conditions that will minimize the binding force between the residual particles and the wafer surface. The morphology and composition of the particle, the surface from which it must be removed, and the environment surrounding the wafer will determine the magnitude of forces that hold a particle to the wafer surface. At the SandiaISEMATECH Center for Contamination Free Manufacturing, two techniques-atomic force microscopy (AFM) and electrokinetic deposition-are being used to explore these interactions for CMP of both oxide and tungsten surfaces. A basic understanding of particle-surface interaction forces and how they are affected by the chemical/physical environment of the particle and surface is the objective of this task. Modification of the binding forces between particles and surfaces may be used to maximize post-CMP cleaning effectiveness. P. Z. Penta-prism long trace profiler (PPLTP) for measurement of grazing Denver 96. Upton, NY: Brookhaven National Lab. 1996 May; BNL-62826. 8 pages, The Long Trace Profiler (LTP) is in use at a number of locations throughout the world for the measurement of the figure and mid frequency roughness of x-ray mirrors. The standard configuration requires that the surface tested lie in a horizontal plane as the optical head is scanned along a horizontal line. For applications where gravity-induced sag of the surface cannot be tolerated, such as in x-ray telescope mirror metrology, it is desirable to measure the mirror as it is mounted in a vertical configuration. By making simple modifications to the standard LTP system, we have demonstrated that it is possible to use the LTP principle to measure the surface of x- ray mirrors and mandrels mounted in the vertical orientation. The major change in the LTP system is the use of a penta prism on a vertical translation stage to direct the probe beam onto the surface and the addition of a precision rotation stage to hold the test object. A 3-D map of the surface topography of the complete cylindrical asphere can be generated quite easily with this technique. Measurements with a prototype system indicate a slope error accuracy of better than 1 microradian is possible, with a figure error repeatability of better than 50 nm. 19 refs., 4 figs. 33. Qian, S.; Li, H.; Takacs,
incidence
space
optics.
34. Spanner, K.; Wolny, W. W.; Lula, B. Plezo actuators move in the nanometer regime. Laser focus World 1996 Nov; 32(11): 6. Lead zirconate titanate (PZT) piezoelectric actuators and motors, coupled with recent advances in piezoelectric materials, controls and testing technology, allow accurate and repeatable motion for measurements in the nanometer range. Enabling technologies like active vibration cancellation and active error compensation improve precision positioning and control. Smart PZT actuators that use coded components and intelligent control electronics, or are integrated with sensor and controller allow system autocalibration. New ways to produce piezoceramics that can meet the piezoelectric, dielectric and mechanical properties required by dynamic actuator applications are also available. Nam, Soo-Ryong. Piezoelectrically driven micro-positioning system for the ductile-mode materials. Journal of Materials Processing Technology. 1996 Sep; 61(3): 309-319. The mirror-like grinding of brittle materials is required in many precision engineering areas. Ductile-mode grinding, a new grinding technology for brittle materials, is considered as a solution of this difficult-to-cut materials grinding. It is known that the fracture mechanism of brittle materials changes to plastic deformation when extremely small depths of grinding or removal rates are employed. In this paper, ductile-mode grinding experiments has been performed using a micro-positioning grinding table that does not require a position sensor, but uses piezoelectric voltage feedback. With hysteresis-considering reference input, it has a sub-micrometer order of displacement resolution. It is established that the characteristics of the ground surfaces change to those associated with plastic deformation for small depths of grinding. 12 Refs.
35. Kim, Jeong-Du;
grinding
of brittle
36. Zhang, L.; Mahdi, M. Plastic behavior of silicon subjected to micro-indentation. Journal of Materials Science. 1996 Nov; 31(21): 5671-5676. Micro-indentation is widely used in evaluating the mechanical properties of ceramics. It is also an important measure in the study of machinability of brittle materials. Because of the complexity of interaction in the vicinity of the contact zone between the indenter and work material, an analytical or experimental method is unable to predict the detailed evolution process of deformation. With the aid of the finite element method, this paper analyses the behavior of a silicon subjected to micro-indentation by a spherical indenter. The development of stress fields was thoroughly simulated. A constitutive relationship was confirmed based on a comparison with experimental observations. This study offers essential information for the indentation of ceramics and a deeper understanding of material removal mechanisms in machining brittle materials. 14 Refs. 37. Bulsara, Vispi H.; Ahn, Yoomin; Chandrasekar, Srinivasan; Farris, Thomas N. Polishing and lapping temperatures. ASMEZSTLE Joint Ttibology Conference; 1996. New York, NY: American Society of Mechanical Engineers; 1996. 8 pages. Polishing is a finishing process in which a smooth work surface is produced by rubbing it against a polishing block with an abrasive slurry interspersed between them. A model has been developed to estimate the temperature rise of the work surface in polishing. In this model, the forces acting on an abrasive particle are derived from a mechanistic analysis of abrasiveworkpiece contacts. The heat generated at a contact is taken as the product of the friction force and the relative sliding velocity between the abrasive and the work surface. For calculating the heat flux transferred into the workpiece, each of the PRECISION
ENGINEERING
149