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

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

This chapter highlights a variety of techniques that are commonly used to measure contact angles, including the conventional telescope-goniometer method, the Wilhelmy balance method, and the more recently developed drop-shape analysis methods. The various applications and limitations of these techniques are described. Notably, studies of ultrasmall droplets on solid surfaces allow wetting theories to be tested down to the nanometer scale, bringing new insight to contact angle phenomena and wetting behavior.

https://www.springer.com/cda/content/document/cda_downloaddocument/9783642342424-c1.pdf?SGWID=0-0-45-1368817-p174704744

Contact Angle and Wetting Properties

Recent development in 2D materials beyond graphene

The term superhydrophilicity is only 11–12 years old and was introduced just after the explosion of research on superhydrophobic surfaces, in response to the demand for surfaces and coatings with exceptionally strong affinity to water. The definition of superhydrophilic substrates has not been clarified yet, and unrestricted use of this term to hydrophilic surfaces has stirred controversy in the last few years in the surface chemistry community. In this review, we take a close look into major definitions of hydrophilic surfaces used in the past, before we review the physics behind the superhydrophilic phenomenon and make recommendation on defining superhydrophilic surfaces and coatings. We also review chemical and physical methods used in the fabrication of substrates on surfaces of which water spreads completely. Several applications of superhydrophilic surfaces, including examples from the authors' own research, conclude this review.

Hydrophilic and superhydrophilic surfaces and materials

Extended DLVO interactions between spherical particles and rough surfaces.

3. FEOL Applications: Device Level 180 3.1. Shallow Trench Isolation (STI) CMP 180 3.2. Replacement Metal Gate CMP 184 3.3. Poly-Si CMP for FinFET Devices 186 4. MOL Applications: Contact Level 187 4.1. Tungsten CMP 187 5. BEOL Applications: Multilevel Interconnects 188 5.1. Copper Interconnect Technology 188 5.2. CMP Challenges in Cu Interconnects 189 5.2.1. Low-k and Ultralow-k Material Challenges 189 5.2.2. Integration Challenges 190 5.2.3. CMP Process Challenges 191 5.3. Copper Planarizarion Process 191 5.4. Ta/TaN Liner CMP Process 193 6. CMP Process-Induced Defects 194 6.1. Defects in FEOL CMP 194 6.2. Defects in MOL Tungsten CMP 195 6.3. Defects in Cu BEOL CMP 195 6.3.1. Corrosion of Copper 196 6.3.2. Scratches 196 6.3.3. Dishing, Erosion, and Trenching 196 6.3.4. Mechanical Damage 197 6.3.5. Other Defects 197 7. Models of CMP Processes 198 7.1. Models Based on Contact Mechanics 198 7.2. CMP Process Models 199 8. Alternative CMP Processes 200 9. Concluding Remarks 201 10. Acknowledgments 201 11. References 201

Chemical mechanical planarization: slurry chemistry, materials, and mechanisms.

A study of bubble–particle interaction using atomic force microscopy

Surface properties of barley straw

The electrokinetic features and interfacial water structure, as revealed from molecular dynamics simulations (MDS) are considered with respect to the anisotropic features of selected two layer silicate minerals. Planar structures of kaolinite and antigorite are compared to the, compositionally equivalent, tubular structures of halloysite and chrysotile with respect to the pH dependency of zeta potential as determined from the electrophoretic mobility measurements. The importance of the atomic mismatch between the tetrahedral and octahedral sheets in a particular bilayer is discussed in order to explain the electrokinetic behaviour of these two layer silicate minerals. Interfacial water structure from MDS suggests that the silica tetrahedral surface is not wetted by water. In the case of planar silicates structural imperfections are considered to explain wetting characteristics. The possibility of polarity reversal (domain inversion) within a tetrahedral/octahedral layer and an out-of-order layer (inserted layer) within the tetrahedral/octahedral stack are considered in order to explain electrokinetic behaviour and wetting characteristics.



Les caracteristiques electrocinetiques et la structure de l'eau interfaciale, telles qu'elles sont revelees par les simulations de dynamique moleculaire (MDS), sont examinees pour determiner les caracteristiques anisotropes des mineraux de silicate a double couche selectionnes. Les structures planaires de la kaolinite et de l'antigorite sont comparees aux structures tubulaires, de composition equivalente, de l'halloysite et du chrysotile pour ce qui a trait a la dependance au pH du potentiel zeta telle qu'elle est determinee par les mesures de mobilite electrophoretique. L'importance de la non-concordance atomique entre les feuilles tetraedriques et octaedriques dans une bi-couche particuliere est examinee afin d'expliquer le comportement electrocinetique de ces deux materiaux de silicate a deux couches. La structure de l'eau interfaciale revelee par les simulations MDS suggere que la surface tetraedrique de la silice n'est pas mouillee par l'eau. Dans le cas de silicates planaires, on pense que des imperfections structurales expliquent les caracteristiques de mouillage. La possibilite d'inversion de polarite (inversion de domaine) dans une couche tetraedrique/octaedrique et la presence d'une couche non-ordonnee (couche inseree) dans l'assemblage tetraedre/octaedre sont envisagees pour expliquer le comportement electrocinetique et les caracteristiques de mouillage.

Surface Characteristics of Kaolinite and Other Selected Two Layer Silicate Minerals

Colloidal forces between atomic force microscopy probes of 0.12 and 0.58 N/m spring constant and flat substrates in nanoparticle suspensions were measured. Silicon nitride tips and glass spheres with a diameter of 5 and 15 mum were used as the probes whereas mica and silicon wafer were used as substrates. Aqueous suspensions were made of 5-80 nm alumina and 10 nm silica particles. Oscillatory force profiles were obtained using atomic force microscope. This finding indicates that the nanoparticles remain to be stratified in the intervening liquid films between the probe and substrate during the force measurements. Such structural effects were manifested for systems featuring attractive and weak repulsive interactions of nanoparticles with the probe and substrate. Oscillation of the structural forces shows a periodicity close to the size of nanoparticles in the suspension. When the nanoparticles are oppositely charged to the probes, they tend to coat the probes and hinder probe-substrate contact.

Jakub Nalaskowski

Papers

Chemical mechanical planarization: slurry chemistry, materials, and mechanisms.

A study of bubble–particle interaction using atomic force microscopy

Surface properties of barley straw

Surface Characteristics of Kaolinite and Other Selected Two Layer Silicate Minerals

AFM colloidal forces measured between microscopic probes and flat substrates in nanoparticle suspensions.