Thermal Imaging of Block Copolymers with Sub-10 nm Resolution.

Thermal silicon probes have demonstrated their potential to investigate the thermal properties of various materials at high resolution. However, a thorough assessment of the achievable resolution is missing. Here, we present a probe-based thermal-imaging technique capable of providing sub-10 nm lateral resolution at a sub-10 ms pixel rate.

Deterministic Deposition of Nanoparticles with Sub-10 nm Resolution.

Accurate deposition of nanoparticles at defined positions on a substrate is still a challenging task, because it requires simultaneously stable long-range transport and attraction to the target site and precise short-range orientation and deposition. Here we present a method based on geometry-induced energy landscapes in a nanofluidic slit for particle manipulation: Brownian motors or electro-osmotic flows are used for particle delivery to the target area. At the target site, electrostatic trapping localizes and orients the particles.

Fast turnaround fabrication of silicon point-contact quantum-dot transistors using combined thermal scanning probe lithography and laser writing.

The fabrication of high-performance solid-state silicon quantum-devices requires high resolution patterning with minimal substrate damage. We have fabricated room temperature (RT) single-electron transistors (SETs) based on point-contact tunnel junctions using a hybrid lithography tool capable of both high resolution thermal scanning probe lithography and high throughput direct laser writing. The best focal z-position and the offset of the tip- and the laser-writing positions were determined in situ with the scanning probe.

Nanofluidic rocking Brownian motors.

Control and transport of nanoscale objects in fluids is challenging because of the unfavorable scaling of most interaction mechanisms to small length scales. We designed energy landscapes for nanoparticles by accurately shaping the geometry of a nanofluidic slit and exploiting the electrostatic interaction between like-charged particles and walls. Directed transport was performed by combining asymmetric potentials with an oscillating electric field to achieve a rocking Brownian motor.

Testing the Equivalence between Spatial Averaging and Temporal Averaging in Highly Dilute Solutions.

Diffusion relates the flux of particles to the local gradient of the particle density in a deterministic way. The question arises as to what happens when the particle density is so low that the local gradient becomes an ill-defined concept. The dilemma was resolved early last century by analyzing the average motion of particles subject to random forces whose magnitude is such that the particles are always in thermal equilibrium with their environment.

Control of the interaction strength of photonic molecules by nanometer precise 3D fabrication.

Applications for high resolution 3D profiles, so-called grayscale lithography, exist in diverse fields such as optics, nanofluidics and tribology. All of them require the fabrication of patterns with reliable absolute patterning depth independent of the substrate location and target materials. Here we present a complete patterning and pattern-transfer solution based on thermal scanning probe lithography (t-SPL) and dry etching.

Sub-10 Nanometer Feature Size in Silicon Using Thermal Scanning Probe Lithography.

High-resolution lithography often involves thin resist layers which pose a challenge for pattern characterization. Direct evidence that the pattern was well-defined and can be used for device fabrication is provided if a successful pattern transfer is demonstrated. In the case of thermal scanning probe lithography (t-SPL), highest resolutions are achieved for shallow patterns.

Accurate Location and Manipulation of Nanoscaled Objects Buried under Spin-Coated Films.

Detection and precise localization of nanoscale structures buried beneath spin-coated films are highly valuable additions to nanofabrication technology. In principle, the topography of the final film contains information about the location of the buried features. However, it is generally believed that the relation is masked by flow effects, which lead to an upstream shift of the dry film's topography and render precise localization impossible.

Surface science. Adhesion and friction in mesoscopic graphite contacts.

The weak interlayer binding in two-dimensional layered materials such as graphite gives rise to poorly understood low-friction characteristics. Accurate measurements of the adhesion forces governing the overall mechanical stability have also remained elusive. We report on the direct mechanical measurement of line tension and friction forces acting in sheared mesoscale graphite structures.

The inverse problem in magnetic force microscopy--inferring sample magnetization from MFM images.

Nanomagnetic structures have the potential to surpass silicon's scaling limitations both as elements in hybrid CMOS logic and as novel computational elements. Magnetic force microscopy (MFM) offers a convenient characterization technique for use in the design of such nanomagnetic structures. MFM measures the magnetic field and not the sample's magnetization.

Calibration of the spring constant of cantilevers of arbitrary shape using the phase signal in an atomic force microscope.

The measurement of cantilever parameters is an essential part of performing a calibrated measurement with an atomic force microscope (AFM). The thermal motion method is a widely used technique for calibrating the spring constant of an AFM cantilever, which can be applied to non-rectangular cantilevers. Given the trend towards high frequency scanning, calibration of non-rectangular cantilevers is of increasing importance.

Performing quantitative MFM measurements on soft magnetic nanostructures.

We have extended our previous work (Rawlings et al 2010 Phys. Rev. B 82 085404) on simulating magnetic force microscopy (MFM) images for magnetically soft samples to include an accurate representation of coated MFM tips.