http://experimentationlab.berkeley.edu/sites/default/files/AFMImages/butt_AFM.pdf

Force measurements with the atomic force microscope: Technique, interpretation and applications

Templated Techniques for the Synthesis and Assembly of Plasmonic Nanostructures

The ability to detect and size individual nanoparticles with high resolution is crucial to understanding the behaviour of single particles and effectively using their strong size-dependent properties to develop innovative products. We report realtime, in situ detection and sizing of single nanoparticles, down to 30 nm in radius, using mode splitting in a monolithic ultrahigh-quality-factor (Q) whispering-gallery-mode microresonator. Particle binding splits a whispering-gallery mode into two spectrally shifted resonance modes, forming a self-referenced detection scheme. This technique provides superior noise suppression and enables the extraction of accurate particle size information with a single-shot measurement in a microscale device. Our method requires neither labelling of the particles nor a priori information on their presence in the medium, providing an effective platform to study nanoparticles at single-particle resolution. With the rapid progress in nanotechnology, nanoparticles of different materials and sizes have been synthesized and engineered as key components in various applications ranging from solar cell

On-chip single nanoparticle detection and sizing by mode splitting in an ultrahigh- Q microresonator

Heat transfer and flow behaviour of aqueous suspensions of TiO2 nanoparticles (nanofluids) flowing upward through a vertical pipe

Materials issues in microelectromechanical systems (MEMS)

In this study, the interfacial and electrokinetic phenomena of mixtures of isopropyl alcohol (IPA) and deionized (DI) water in relation to semiconductor wafer drying is investigated. The dielectric constant of an IPA solution linearly decreased from 78 to 18 with the addition of IPA to DI water. The viscosity of IPA solutions increased as the volume percentage of IPA in DI water increased. The zeta potentials of silica particles and silicon wafers were also measured in IPA solutions. The zeta potential approached neutral values as the volume ratio of IPA in DI water increased. A surface tension decrease from 72 to 23 dynes/cm was measured when the IPA concentration increased to 30 vol %. The surface excess of IPA at the air-liquid interface reached a maximum at around 20 vol % IPA. The adhesion forces of silica particles on silicon wafers were measured using atomic force microscopy in IPA solutions. The adhesion force increased as the volume percent of IPA in water increased. Lower particulate contamination was observed when the wafers were immersed and withdrawn from solutions containing less than 25 vol % IPA.

https://repository.library.northeastern.edu/files/neu:329881/fulltext.pdf

Interfacial and electrokinetic characterization of IPA solutions related to semiconductor wafer drying and cleaning

Evaluation of double sided lapping using a fixed abrasive pad for sapphire substrates

The removal of nanoparticles is becoming increasingly challenging as the minimum linewidth continues to decrease in semicon-ductor manufacturing. In this paper, the removal of nanoparticles from ﬂat substrates using acoustic streaming is investigated. Baresilicon wafers and masks with a 4 nm silicon cap layer are cleaned. The silicon-cap ﬁlms are used in extreme ultraviolet masks toprotect Mo–Si reﬂective multilayers. The removal of 63 nm polystyrene latex PSL particles from these substrates is conductedusing single-wafer megasonic cleaning. The results show higher than 99% removal of PSL nanoparticles. The results also showthat dilute SC1 provides faster removal of particles, which is also veriﬁed by the analytical analysis. Particle removal from the4 nm Si-cap substrate is slightly more difﬁcult as compared to bare silicon wafers. The experimental results show that the removalof nanoparticles takes a relatively long removal time. Numerical simulations showed that the long time is due to particleoscillatory motion and redeposition, and that this phenomenon is not observed in the removal of sub- m or larger size particles.© 2006 The Electrochemical Society. DOI: 10.1149/1.2217287 All rights reserved.Manuscript submitted January 9, 2006; revised manuscript received April 24, 2006. Available electronically July 19, 2006.

https://repository.library.northeastern.edu/files/neu:329875/fulltext.pdf

Experimental and Numerical Investigation of Nanoparticle Removal Using Acoustic Streaming and the Effect of Time

Chemical mechanical planarization (CMP) has become one of the most critical processes in semiconductor device fabrication to achieve global planarization. To achieve an efficient global planarization for device node dimensions of less than 32 nm, a comprehensive understanding of the physical, chemical, and tribo-mechanical/chemical action at the interface between the pad and wafer in the presence of a slurry medium is essential. During the CMP process, some issues such as film delamination, scratching, dishing, erosion, and corrosion can generate defects which can adversely affect the yield and reliability. In this article, an overview of material removal mechanism of CMP process, investigation of the scratch formation behavior based on polishing process conditions and consumables, scratch formation mechanism and the scratch inspection tools were extensively reviewed. The advantages of adopting the filtration unit and the jet spraying of water to reduce the scratch formation have been reviewed. The current research trends in the scratch formation, based on modeling perspective were also discussed.

/pdf/scratch-formation-and-its-mechanism-in-chemical-mechanical-3l5jk3f4c2.pdf

Scratch formation and its mechanism in chemical mechanical planarization (CMP)

The adhesion force of silica particles to Cu films and the role of additives on adhesion and removal of particles have been theoretically and experimentally investigated in citric-acid-based post-Cu chemical mechanical planarization (CMP) cleaning solutions. The zeta potential of silica and Cu slightly increases when citric acid is added due to the adsorption of citrates. Citric acid is adsorbed on silica and Cu surfaces, resulting in more negative charges on these surfaces. The adhesion force of silica particles on Cu decreases as the citric acid concentration increases due to more repulsive electrostatic interaction between surfaces. The addition of benzotriazole in the cleaning solution initially decreases adhesion then increases it at high concentrations due to the change in zeta potentials. The addition of tetramethylammonium hydroxide to citric acid increases the particle adhesion force. However, the addition of NH 4 OH results in the lowest adhesion forces. The highest particle removal efficiency is observed when using cleaning solutions that yield the lowest adhesion force.

https://iopscience.iop.org/article/10.1149/1.1802493/pdf

Jin-Goo Park

Papers

Interfacial and electrokinetic characterization of IPA solutions related to semiconductor wafer drying and cleaning

Evaluation of double sided lapping using a fixed abrasive pad for sapphire substrates

Experimental and Numerical Investigation of Nanoparticle Removal Using Acoustic Streaming and the Effect of Time

Scratch formation and its mechanism in chemical mechanical planarization (CMP)

The Effect of Additives in Post-Cu CMP Cleaning on Particle Adhesion and Removal