Wear‐Resistant Nanoscale Silicon Carbide Tips for Scanning Probe Applications

Abstract

The search for hard materials to extend the working life of sharp tools is an age-old problem. In recent history, sharp tools must also often withstand high temperatures and harsh chemical environments. Nanotechnology extends this quest to tools such as scanning probe tips that must be sharp on the nanoscale, but still very physically robust. Unfortunately, this combination is inherently contradictory, as mechanically strong, chemically inert materials tend to be diffi cult to fabricate with nanoscale fi delity. Here a novel process is described, whereby the surfaces of pre-existing, nanoscale Si tips are exposed to carbon ions and then annealed, to form a strong silicon carbide (SiC) layer. The nanoscale sharpness is largely preserved and the tips exhibit a wear resistance that is orders of magnitude greater than that of conventional silicon tips and at least 100-fold higher than that of monolithic, SiO-doped diamond-like-carbon (DLC) tips. The wear is well-described by an atom-byatom wear model, from which kinetic parameters are extracted that enable the prediction of the long-time scale reliability of the tips.

Fabrication and characterization of boron-doped nanocrystalline diamond-coated MEMS probes

“…Several over-coated nanodevices have been proposed to mitigate conductive tip coating, including platinum silicide tips [10], silicon dioxide tip encapsulation [11], silicon carbide tips [12] and diamond or diamond-like carbon tips [13,14]. However, noble metal-coated conductive tips exhibit disadvantages, narrow potential window or electrode fouling when applied in electrochemical nanodevices [15].…”

Robust Free‐Standing Nano‐Thin SiC Membranes Enable Direct Photolithography for MEMS Sensing Applications

“…[6][7][8][9] In addition, owing to the corrosive tolerance and mechanical robustness, SiC has also been utilized as a coating layer to improve the wear resistance of devices and instruments. [10,11] Among more than 200 types of SiC crystals, cubic silicon carbide, which can be epitaxially grown on Si substrates, has attracted great attention. The different physical properties between SiC and Si such as thermal expansion, crystal lattice sizes, and different band gaps result in numerous interesting phenomena including large residual stress and the SiC/Si heterojunction.…”

Amorphization-assisted nanoscale wear during the running-in process

“…Since its invention, atomic force microscopy (AFM) has been widely used for studying surface features and manipulating materials from the atomic to the micron scale. The quality of AFM-based measurements and manufacturing processes are critically dependent on the reliability and durability of AFM tip itself [1][2][3][4][5]. However, the contact between the tip and sample, and the associated high mechanical stress and/or chemical reactions, can result in wear of the tip during use [6][7][8][9][10][11][12][13].…”