K. Ivanova

Micromachined atomic force microscopy sensor with integrated piezoresistive sensor and thermal bimorph actuator for high-speed tapping-mode atomic force microscopy phase-imaging in higher eigenmodes

This article describes microprobes for noncontact scanning force microscopy that make use of a direct-oscillating thermally driven bimorph actuator with integrated piezoresistive readout sensor. The sensitivity has been increased using direct current for biasing and alternating current for exciting the thermally driven cantilever in a higher flexural mode. The cantilever operates in the phase-shift atomic force microscopy (AFM) detection technique. The main advantage of phase imaging is the higher z resolution at high scan rates and much lower forces than in height imaging with contact AFM. Critical dimensions measurements illustrating the imaging capability and resolution of our new scanning proximal probe are demonstrated.

Scanning proximal probes for parallel imaging and lithography

Scanning proximity probes are uniquely powerful tools for analysis, manipulation, and bottom-up synthesis. A massively parallel cantilever-probe platform is demonstrated. 128 self-sensing and self-actuated proximal probes are discussed. Readout based on piezoresistive sensors and bending control based on bimorph dc/ac actuations are described in detail.

Micromachined piezoresistive proximal probe with integrated bimorph actuator for aligned single ion implantation

The authors report a microfabrication procedure of self-actuated piezoresistive scanning probes (SAPSPs). They are designed for a SAPSP instrument that is integrated with an ion beam for aligned single ion implantation in ultrahigh vacuum. The novelty of the design is an integrated hollow pyramid, instead of a previously mechanically hand mounted pyramid [J. Vac. Sci. Technol. B 23, 2798 (2005)]. The pyramid has dual purpose. First it collimates the ion beam and suppresses secondary particles from the back side of the cantilever, so that secondary particles from the target material can be used for single ion detection. Second the pyramid also provides an atomic force microscope tip for the scanning probe. A crucial step in the fabrication is the back side opening via etching for the hollow pyramid. The fabrication procedure will be discussed in detail.

Single ion implantation with scanning probe alignment

We present results from our development of a single ion implantation technique integrated with a scanning force microscope. Accurate alignment at the 5nm level is a crucial requirement for reliable single ion placement. We address this through integration of the ion beam with a scanning probe tip containing an aperture. Single ion registration is based on detection of secondary electron bursts from single, high charge state ions. We describe formation of scanning probe tips with holes and sensing poles by focused ion and electron beam processing (drilling and thin film deposition). Ion transport studies through apertures show stable transmission for >10h with 1nA scale beam intensities on precollimators.

Micromachined Arch-type cantilever as high sensitivity uncooled infrared detectora)

In this article, we discuss an uncooled infrared (IR) detector based on an “arch-type” design realized with advanced microelectromechanical systems technology. Bimaterial microcantilevers undergo bending as their temperature changes due to the absorption of infrared photons. The bending is proportional to dissimilar thermal expansion of the two different materials composing the cantilever. We select the most optimal combination of materials used commonly in the micromachining technology resulting in highest bimaterial effect. Well known SU8 negative resist is one promising candidate having high thermal expansion coefficient (α=52×10−6∕K), and relatively low thermal conductivity (0.2W∕mK). Creating a micromechanical “arch” shaped cantilever a differential stress is induced due to different thermal expansion of middle beam formed from the SU8-film. Moreover, we fabricate a design microcantilever IR detector that consists two unique skills: (i) a Si/SU8 bimaterial system as material combination with benefici...

Parallel proximal probe arrays with vertical interconnections

This article presents the fabrication and the characteristics of 8×64, parallel, self-actuated, and independently addressable scanning proximal probes with through-silicon via interconnection passing completely through a silicon wafer. The low-resistance highly doped polysilicon through-wafer electrical interconnects have been integrated with scanning proximal probes (SPPs) to enable back side contacts to the application-specific integrated circuit used as an atomic force microscope control circuitry. Every SPP sensor contains a deflection sensor, thermally driven bimetal (bimorph) actuator, and sharp silicon tip. Dry etching-based silicon on insulator three-dimensional-micromachining technique is employed by the creation of the through-silicon vias and the SPP arrays keeping fully complementary metal-oxide semiconductor compatible process regime. The application of the vertical interconnection technology in large-scale two-dimensional cantilever arrays with off-plane bent cantilevers over the chip’s surf...