Michael Vinogradov

Effects of slurry flow rate and pad conditioning temperature on dishing, erosion, and metal loss during copper CMP

Center for USA The effect of slurry flow rate, pad surface temperature, and temperature during the pad conditioning process on surface tribology and pattern-related defects like dishing, erosion, and metal loss was studied. Experimental results suggest that dishing and erosion levels decreased with increase in slurry flow rate. Conditioning experiments at various temperatures revealed a significant impact of temperature on the effectiveness of the conditioning process and also on subsequent polishing performance. The polishing pad was conditioned more aggressively at lower temperatures compared to conditioning at elevated temperatures. The removal rate and coefficient of friction were found to be significantly affected by the pad surface temperature. The amount of dishing increased with increase in pad surface temperature and the uniformity of polishing. The study ascertains a correlation between process parameters and the extent of planarity defects. This study also demonstrates the use of a modified bench-top chemical mechanical polish (CMP) tester and large-stage atomic force microscope with automatic multiscan imaging procedure.

Comprehensive Mechanical and Tribological Characterization of Ultra-Thin-Films

Based on recent studies, mechanical and tribological properties such as hardness, Youngs modulus, friction, and scratch adhesion strength on various coatings and ultra-thin films are reported. These results were obtained using a Universal Nano+Micro Tester UNMT-1, suitably designed for comprehensive evaluation of mechanical and tribological properties of bulk materials, coatings and thin films. Results indicate that a substrate effect for ultra-thin films is substantial when using conventional static nanoindentation technique, while negligible with an advanced dynamic nano-indentation. Comparative results of hardness and Youngs modulus obtained from various techniques are presented. Also, a means to evaluate friction and adhesion strength of thin films is highlighted, using DLC specimens as an example.

In-Situ Quantitative Integrated Tribo-SPM Nano-Micro-Metrology

A novel quantitative nano/micro-tribometer with integrated SPM and optical microscope imaging has been developed to characterize numerous physical and mechanical properties of liquid and solid thin films and coatings, with in-situ monitoring their changes during micro and nano indentation, scratching, reciprocating, rotating and other tribology tests. Both the materials properties and surface topography can be assessed periodically during the tests.Copyright

Non-Destructive High-Resolution Stiffness Mapping of Composite Engineered Surfaces

Experimental evaluation of hardness, adhesion and Young’s modulus has been performed on polyimide polymeric coatings used in LCD displays and on composite polymer-based materials used in automobiles and aircraft. A novel Universal Nano+Micro Tester UNMT-1 with a nano-analyzer module NA-2 has been utilized. It measures scratch-hardness of coatings and thin films, utilizing the same nano-tip for both scratching and nano-imaging under the constant load. It measures scratch-adhesion with the same diamond tip for both scratching and nano-imaging under the continuously-increasing load. It evaluates homogeneity of films and composite materials by simultaneous Young’s modulus and topography nano-mapping, with a diamond nano-tip in a tapping mode, while frequency and phase of its vibrations are analyzed. The Young’s modulus maps allowed us to evaluate the distribution of SiO/Si02 particles embedded in araldite, with varying SiO/Si02 concentration. While the topography images could not distinguish between the particles and polymeric matrix, the nano-mechanical maps revealed the effects of particle concentration and agglomeration on the local modulus of the material and the relationship between the SiO/Si02 uniformity and uniformity in modulus. The nano-scratches of 60-nm polyimide coatings at progressively increasing and constant loads generated adhesion and scratch-hardness data, respectively. Within the applied loads of 20 to 100 μN, we observed and determined both the critical load, at which the coating was delaminated from the glass substrate, and a corresponding lateral delamination force. The mutually complimentary nano-images and force graphs coincided nicely.Copyright

Integrated Multi-Sensor Tribo-SPM Nano+Micro Tribo-Metrology

A novel quantitative nano+micro tribometer with integrated AFM and optical microscope has been utilized to characterize tribological and mechanical properties of liquid and solid thin films and coatings, with in-situ monitoring their changes during micro and nano indentation, scratching, reciprocating, rotating and other tribology tests.© 2005 ASME

Advanced Methods of Coating Adhesion Testing

Adhesion of coatings from 1 nm to 0.1 mm was successfully evaluated with multi-sensing technology, based on simultaneous high-resolution force, electrical and acoustic measurements. Sharp changes in the signals were indicative of the thresholds of adhesion and delamination for various thin and thick coatings during scratching and indenting with several test tools, both sharp (diamond tips) and dull (balls).

In-Situ Tribological Properties Monitoring and Chemical Mechanical Characterization of Planarization Process

For faster signal propagation in integrated circuits, new materials with lower dielectric constant (low-k) values are required with copper metal lines. Although integration of low-k materials (k<3.0) has been demonstrated, but ultra low-k materials possess many challenges due to their poor mechanical integrity and weak adhesion to other interconnects. During chemical mechanical planarization (CMP) generation of several defects including delamination of low-k materials is severe problem in the integration of these materials. Different slurries and pad introduces different levels of defect and also batch-to-batch variation in consumables is often makes process more difficult. In this study we have investigated the tribological properties of CMP pad and wafer interface while monitoring coefficient of friction and acoustic emission data. Signals are analyzed in order to online defect monitoring, batch-to-batch consumable variations and different consumables effects.Copyright