Ultra-high density MEMS probe memory device

Control Methods in Data-Storage Systems

“…The microcantilevers are actuated electrostatically, and are equipped with thermal sensors that can detect the probe distance from the storage medium. Competing systems are based on a very similar design, e.g., the device reported in [227] uses an array of 5000 electrostatically actuated microcantilevers spaced at 150 m pitch.…”

“…However, none are fully compatible with standard fabrication processes [228]- [230]. With some exceptions [231], [232], electromagnetic actuators are used in most of the prototype probe-based storage systems to move the scan table in the -plane [227], [233], [234], [269]. Although this method of actuation is not compatible with available MEMS fabrication methods, it is chosen for its ability to generate a large stroke at reasonable power consumption.…”

“…Although many capacitive transducers have a nonlinear capacitance vs. displacement characteristic, feedback is commonly used to convert the signal to a linear output. This method has been used in two of the prototype probe-storage systems demonstrated, for which nanometer-level positioning accuracies have been reported [227], [239]. They have also been used in [232] where these electrostatic actuators are exploited for simultaneous sensing.…”

Ultrahigh Density Probe-based Storage Using Ferroelectric Thin Films

“…The probe-based seek-and-scan data storage system is an ideal candidate for future ultrahigh-density (> 1 Tbit/ inch 2 ) nonvolatile memory devices (Vettiger et al, 2002;Pantazi et al, 2008;Hamann et al, 2006;Ahn et al, 1997;Cho et al, 2003;Cho et al, 2005;Ahn et al, 2004;Cho et al, 2006;Heck et al, 2010). In such a system, an atomic force microscope (AFM) probe (or an array of AFM probes) is used to write and read data on a nonvolatile medium; the bit size depends mainly on the radius of the probe tip.…”

“…Another advantage of probe-based memory is that the mechanism to move the probes is low power, which reduces power consumption and heat dissipation in comparison to HDD devices. While various writing mechanisms have been proposed for probe-based storage, e.g., thermomechanical and thermal writings on polymeric and phase-change media (Vettiger et al, 2002;Pantazi et al, 2008;Hamann et al, 2006), a great deal of attention has recently been devoted to the electrical pulse writing on ferroelectric films due to the non-structuredestructive nature of the write-erase mechanism (Ahn et al, 1997;Cho et al, 2003;Cho et al, 2005;Ahn et al, 2004;Cho et al, 2006;Heck et al, 2010). When a short electrical pulse is applied through a conductive probe on a ferroelectric film, the highly concentrated electric field can invert the polarization of a local film volume, resulting in a nonvolatile ferroelectric domain that is the basis of data recording.…”