The thermal and spatial variation of Cu TSV-induced stress has been investigated for 1×4 arrays of 5 μm diameter × 50 μm TSVs using microRaman imaging. Following post-CMP annealing the measured Si Raman shift outside the TSV array is slightly modified. In strong contrast, the Si Raman shift midway between TSVs transitions from a tensile to compressive state as the annealing temperature increases. Topographic analysis implies this shift is associated with thermally-induced Cu extrusion.

A novel multi-walled carbon nanotube (MWNT) growth process is reported based on carbon incorporation in a nickel catalyst layer deposited via plasma-enhanced atomic layer deposition (PEALD) on silicon nanowires and silicon wafer substrates. As-deposited PEALD Ni films containing relatively high amounts of carbon (> 18 at.%) were observed to promote the growth of MWNTs upon post-deposition rapid thermal annealing. For these films the carbon originated from the ALD precursor ligand and MWNT growth occurred in the absence of a vapor-phase carbon feedstock. MWNT growth relied on the formation of nickel silicide at the PEALD Ni/Si interface which increased the local carbon concentration in the Ni film sufficiently to promote carbon saturation/precipitation at Ni catalyst grains and nucleate MWNT growth. Similar MWNT growth from annealed PEALD Ni films was not observed on SiO(2)-coated Si wafer substrates, consistent with the role of silicidation in the observed Ni-catalyzed MWNT growth on Si. This MWNT growth mode requires neither the catalytic decomposition of a gaseous hydrocarbon source nor the high-temperature pyrolysis of metallocene materials and purposely avoids a catalyst diffusion barrier at the Si substrate, commonly used in MWNT growth processes on Si.

Experimental investigations are presented regarding the surface-selective molecular selfassembly of fluorinated monochloroalkylsilane of the type (heptadecafluoro-1,1,2,2-tetrahydrodecyl) dimethylchlorosilane (denoted F17) on silicon dioxide (SiO2) and silicon nitride (Si3N4) surfaces. The goal is to investigate the controlled and selective surface self-assembly of these molecules as a potential route for substrate-selective covalent bonding of complex molecular assemblies to semiconductor substrates for on-chip interconnect and device applications. X-ray photoelectron spectroscopy (XPS), x-ray reflectivity (XRR) and atomic force microscopy (AFM) have been used to investigate the selectivity of the F17 self-assembly. Contrary to previous reported results, a high degree of F17 monolayer attachment selectivity is consistently observed between SiO2 and Si3N4 substrates for all three of the aforementioned monolayer characterization methods.

The College of Nanoscale Science and Engineering (CNSE) at the University at Albany has developed an academic curriculum leading to the degree of Bachelor of Science in Nanoscale Science. This curriculum represents a 132-credit program designed for completion in eight academic semesters and is consistent with the SUNY General Education Program requirements as implemented at the University at Albany. This curriculum comprises a cutting-edge, inherently interdisciplinary, academic program centered on scholarly excellence, educational quality, and technical and pedagogical innovation. The blueprint for this curriculum is comprised of four basic components: a “Foundational Principles”’ component, a “Core Competency” component, a “Concentration” component and a “Capstone Research/Design” component. The first two components are designed to integrate the dissemination of fundamental, cross-disciplinary, nanoscale science and engineering principles with the cultivation of the critical skill set necessary for advanced undergraduate coursework and interdisciplinary research. The remaining two components expand on these foundational skills to develop the topical expertise, technical depth, and independent research abilities that are essential to a well-rounded undergraduate educational experience. The combination of these instructional tools ensures a customizable and coherent undergraduate degree program that trains the student’s intellect how to explore, discover, and innovate, while ensuring its proficiency in a specific nanoscale discipline. The outcome is a unique undergraduate experience that taps into CNSE’s global academic leadership in nanoscale science and engineering to attract and educate a diverse and talented pool of qualified scientists and engineers at the baccalaureate level.

Nanoscale metrology (thickness, defectivity) of carbon-based devices is a substantial challenge due to device dimension scaling. Development of graphene-based nanoelectronics required solutions for thickness and defect metrology owing to the difficulty of probing the atomic structure of individual graphene sheets. Distinguishing the number of graphene layers for a particular test structure as well as quantifying disorder for local defect characterization is essential to study graphene based devices. Raman spectroscopy has proved to be an appropriate approach in this regard for identifying and distinguishing the number graphene layers in thin (n < 4) multilayer exfoliates by signatures of the 2D Raman band. Raman spectroscopy is capable not only in establishing the registry of graphene flakes but also in identifying defects present by study of D (defect) bands. In this work we have employed Raman thickness metrology protocols with customized commercial graphene exfoliates to distinguish mono and bi layer graphene flakes deposited on test structures via analysis of the Raman 2D bands. Raman spectra of CVD graphene deposited on similar test structures have also been investigated. Defects introduced by controlled dose, e-beam irradiation have likewise been analyzed. The evolution of defect induced D bands in Raman and the I(D)/I(G) ratios are used to establish relative defect densities.

Nanoscale metrology of graphene-based devices is a substantial challenge. The investigation of defects and stacking order is essential for graphene-based device development. Raman spectroscopy is a useful approach in this regard. The defect-induced Raman D band yields substantial insights regarding defect density and, consequently, can serve as in important tool to quantify impact of defects on eventual graphene-based device performance. Toward this end an investigation of electron beam-induced defects in bi-layer and mono layer graphene samples has been undertaken via the examination of the Raman D, and G bands. The evolution of the aforementioned Raman spectra as a function of electron beam dose was characterized via Raman spectroscopy and compared with spectra from the same samples prior to irradiation. Defect generation in the graphene as a function of electron beam dose was characterized via the change in the intensity ratios of the Raman D and G bands (I-D/I-G) and the broadening of the G band line width. Continued irradiation at very high flux and very low accelerating voltages have also revealed charge accumulation evident from the narrowing of G band line-widths.

The relative surface contact stiffness of SnO2 nanobelts has been investigated via ultrasonic force microscopy (UFM). The nanobelt crystal structure, as determined via transmission electron microscopy, was indexed to the tetragonal rutile structure (with lattice constants identical to those of bulk SnO2) as reported previously. The atomic Sn:O composition of the nanobelts studied was at or near 1:2. Topographic imaging studies revealed the nanobelt surface to be atomically flat with the exception of surface nanodots, assumed to be local SnO2 crystallites. Preliminary reduced modulus measurements were carried out via differential UFM on both the flat and nanodot regions of the nanobelt. Using the underlying Si substrate as a calibration standard the SnO2 modulus was estimated at 157±12 GPa, significantly lower than corresponding bulk values for any of the observed crystal orientations. We speculate this discrepancy is due in part to a combination of the aspherical probe tip and unknown adhesive properties of nanobelt. An intrinsic reduction of the SnO2 nanobelt modulus cannot be ruled out.

Nanomechanical mapping of individual multi-walled carbon nanotubes (MWNTs) has been undertaken to investigate intra-tube variations of mechanical response. Ultrasonic force microscopy has been used to measure the relative axial and radial variations of contact stiffness of individual MWNTs synthesized using chemical vapor deposition (CVD) and arc-discharge (AD) techniques. For CVD-based MWNTs the contact stiffness of the tube was seen to vary strongly across volume defects (axial variation of the tube radius) and is assumed to result from the high crystalline defect density associated with such radial variations. These observations support recent experimental data of effective Young's modulus inferred from electrostatically-induced nanotube vibration amplitudes.

The investigation of an alternate approach to nondestructive, nanoscale mechanical imaging for IC interconnect structures is reported. This approach utilizes a heterodyne interferometer based on a scanning probe microscope, also referred to as heterodyne force microscopy (HFM). This interferometer is sensitive to the relative phase difference of the two ultrasonic excitations due to spatial variations in the sample viscoelastic response and enables near-field, phase-sensitive imaging. Proof-of-feasibility demonstrations of this technique are presented for ultrasonic phase-imaging of Al/low-k interconnect structures. Spatial resolution < 10 nm is demonstrated.

In this study, the Focused Ion Beam (FIB) instrument has been used for carbon nanotubes integration and nanoegineering studies. Results of thorough investigation (electrical, structural and chemical) of ultra-thin Pt contact lines and pads fabricated by the FIB, along with evaluation of nanomodification of the carbon nanotubes under the Ga + ion beam and during Pt deposition are presented. The initial stages of FIB-assisted Pt deposition on multi-wall nanotubes are studied by transmission electron microscopy (TEM). The FIB parameters are optimized to provide non-destructive imaging and controllable Pt deposition with minimal damage on the nanotubes. We have demonstrated effective use of FIB-fabricated Pt pads as means of attaching the nanotubes to the substrate for atomic force and ultrasonic force microscopy studies.

A new characterization tool based on ultrasonic force microscopy (UFM) has been developed to image the nanometer scale mechanical properties of aluminum/low-k polymer damascence integrated circuit (IC) test structures. Aluminum and polymer regions are differentiated on the basis of elastic modulus with a spatial resolution ≤ 10 nm. This technique reveals a reactive-ion etch (RIE)-induced hardening of the low-k polymer that is manifested in the final IC test structure by a region of increased hardness at the aluminum/polymer interface. The ability to characterize nanometer scale mechanical properties of materials used for IC back-end-of-line (BEOL) manufacture offers new opportunities for metrological reliability evaluation of low-k integration processes.

Currently, the IC industry is researching the integration of a variety of materials to meet the low dielectric constant requirement for improved back-end of line (BEOL) interconnect performance. One critical dimension for successful ntegration of these new materials is maintaining mechanical integrity through multilayer processes. This includes both cohesive and adhesive fracture resistance. The latter adds additional complexity in that adhesive toughness is a function of the adherend materials and the processes used to join them. Hence, many good dielectric materials may be rematurely eliminated from further research not because of inherently poor adhesion but because of the necessity to optimize processing strategies. In this paper, we use the modified Edge Liftoff Test (m-ELT) to quantify the mechanical adhesion of multilayer blanket coatings. A specific example is used to demonstrate the utility of combining the m-ELT with surface analysis to optimize the reliability of low-K dielectric resins for use in ULSI applications. The system studied consists of a Cyclotene ™ 5021(BCB) low-K material integrated with CVD aluminum for single level, damascene structures. The effects of liner layer metallurgy and surface plasma treatments are measured. Surface analysis is done on the failed parts to understand the location of the failure. In this way recommendations for process optimization can be made.

Positively charged polydiallyldimethylammonium chloride, P, was found to bind strongly to the surface of anionic montmorrillonite, M, platelets in aqueous dispersions up to a saturation (estimated to correspond to the binding of five P to one 1.0 nm × 200 nm M platelet) beyond which reversible physisorption occurred. Immersion of a substrate (glass, quartz, silica-wafer, gold, silver, and even Teflon) into an aqueous 1% solution of P and rinsing with ultrapure water for 10 min resulted in the strong adsorption of a 1.6 nm thick P on the substrate. Immersion of the P coated substrate into an aqueous dispersion of M and rinsing with ultrapure water for 10 min led to the adsorption of 2.5 nm thick M. Repeating the self-assembly steps of P and M for n number of times produced (P/M)n self-assembled films. Thickness of the M layer was found to depend on the external voltage applied during its self-assembly:  applying a positive potential during the self-assembly of M increased the thickness of the M layer; appl...

Chemisorbed monolayers of decyltrichlorosilane, [11-(2-Naphthyl)undecyl]trichlorosilane, and a coadsorbed binary mixture of the two were prepared and subsequently investigated using lowangle x-ray reflectivity. Electron density profiles calculated from this data combined reveal well-defined naphthyl and alkyl regions in the [11-(2-Naphthyl)undecyl]trichlorosilane monolayer indicating a high degree of registry along the film normal. These conclusions are consistent with previous spectroscopic measurements of the same system.

Results of our x-ray specular reflectivity studies on multilayer films of a ferroelectric liquid-crystal polymer are presented. The reflectivity curves are characterized by interference fringes (Kiessig fringes) that occur between successive Bragg peaks. Two types of intensity variations of the Kiessig fringes are observed a uniform variation and a modulated variation. The latter is shown to be due to a single-layer defect which percolates throughout the multilayer film. The electron density profiles are determined from Fourier analysis of the reflectivity.