Recently, organic nonvolatile memory devices have attracted considerable attention due to their low cost and high performance. This article reviews recent developments in organic nonvolatile memory and describes in detail an organic electrical bistable device (OBD) that has potential for applications. The OBD consists of a tri-layer of organics/metal nanoclusters/organics sandwiched between top and bottom electrodes. A sufficiently high applied bias causes the metal nanoparticle layer to become polarized, resulting in charge storage near the two metal/organic interfaces. This stored charge lowers the resistance of the device and leads to an electrical switching behavior. The ON and OFF states of an OBD differ in their conductivity by several orders of magnitude and show remarkable bistability—once either state is reached, the device tends to remain in that state for a prolonged period of time. More important, the conductivity states of an OBD can be precisely controlled by the application of a positive voltage pulse (to write) or a negative voltage pulse (to erase). Device performance tests show that the OBD is a promising candidate for high-density, low-cost electrically addressable data storage applications.

The elimination of conventional peripheral LSI (large-scale integration) drivers is considered essential to the development of future low-cost, energy-efficient, lightweight, and thin displays. System-on-glass (SOG) displays are a type of display with various functional circuits integrated on a glass substrate. Low-temperature polycrystalline silicon (LTPS) thin-film transistors (TFTs) make the integration of circuits possible because they can be assembled into complex, high-current driver circuits. Furthermore, LTPS TFTs are attracting attention for driving organic light-emitting devices (OLEDs). This article introduces present and future LTPS TFT technologies for SOG displays.

Chemical–mechanical polishing, or planarization (CMP), is one of several advanced microfabrication processes that provide complementary capabilities for constructing advanced electronic devices. At the current state of the art, CMP demonstrates significant advantages due to its high degree of process flexibility, particularly in the chemical formulation of polishing solutions and slurries. This article explores some possible future applications of CMP using new advanced materials other than silicon, silicon oxide, and silicon nitride. Such materials may include refractory and noble metals, high-κ insulators, and mixed metal oxide perovskites. Although no one can predict future applications with absolute certainty, it seems safe to conclude that CMP will remain a key microfabrication technology for the foreseeable future.

Combinatorial methods are high-efficiency methods to create large composition “libraries” of materials, for example, continuous composition variations, and test those compositions systematically in parallel for specific properties of interest, in contrast to the time-consuming one-composition-at-a-time approach. These methods have captured the attention of the materials industry with the promise of providing new discoveries “faster, better, and cheaper.” However, in the academic community, combinatorial methods often meet with less enthusiasm, perhaps due to the perception of combinatorial methodology as an Edisonian approach to science. The facts are quite to the contrary. In addition to impressive successes arising from the application of combinatorial methods to materials discovery, results coming out of systematic high-throughput investigations of complex materials phenomena (which would be too time-consuming or expensive to undertake) provide data leading to improvement in theories and models of materials chemistry and physics. Indeed, combinatorial methods provide a new paradigm for advancing a central scientific goal—the fundamental understanding of structure–property relationships of materials behavior.

Shape-memory alloy (SMA) thin films formed by sputter deposition have attracted considerable attention in the last decade. Current intensive research demonstrates that unique fine microstructures are responsible for the superior shape-memory characteristics observed in thin films as compared with bulk materials. Simultaneously, much effort has been undertaken to develop and fabricate micro devices actuated by SMA thin films. This article reviews the research to date on shape-memory behavior and the mechanical properties of SMA thin films in connection with their peculiar microstructures. Promising applications such as microvalves are demonstrated, along with a focused discussion on process-related problems. All of the results indicate that thin-film shape-memory actuators are ready to contribute to the development of microelectromechanical systems.

Many advanced technologies center on devices of small feature sizes made of diverse materials. Internal stresses that arise in the devices during fabrication and use can result in fracture. Fracture of an individual feature in such a device may impair the function of the device. The materials surrounding the feature have a constraining effect on the elastic energy available to drive the fracture, the plastic flow associated with the fracture, and sometimes even the atomic processes at the crack tip. This article reviews fracture behavior in small structures, several distinct roles played by plasticity, and bond-breaking kinetics. Research challenges are alsooutlined.

As-deposited thin films grown by vapor deposition often exhibit large intrinsic stresses that can lead to film failure. While this is an “old” materials problem, our understanding has only recently begun to evolve in a more sophisticated fashion. Sensitive real-time measurements of stress evolution during thin-film deposition reveal a generic compressive–tensile–compressive behavior that correlates with island nucleation and growth, island coalescence, and postcoalescence film growth. In this article, we review the fundamental mechanisms that can generate stresses during the growth of Volmer–Weber thin films. Compressive stresses in both discontinuous and continuous films are generated by surface-stress effects. Tensile stresses are created during island coalescence and grain growth. Compressive stresses can also result from the flux-driven incorporation of excess atoms within grain boundaries. While significant progress has been made in this field recently, further modeling and experimentation are needed to quantitatively sort out the importance of the different mechanisms to the overall behavior.

This article describes the current level of understanding of dislocation plasticity in thin films and small structures in which the film or structure dimension plays an important role. Experimental observations of the deformation behavior of thin films, including mechanical testing as well as electron microscopy studies, will be discussed in light of theoretical models and dislocation simulations. In particular, the potential of applying strain-gradient plasticity theory to thin-film deformation is discussed. Although the results of all studies presented follow a “smaller is stronger” trend, a clear functional dependence has not yet been established.

Under certain circumstances, decreasing the dimensions of a material may lead to elastic or anelastic properties that diverge from bulk behavior. A distinction is made between elastic deformation, for which bond rearrangements are not required, and anelastic behavior, which involves reversible deformation due to defect motion. Elastic deformation (due to bond stretching) remains structure-insensitive down to near-atomic length scales, and only small deviations are expected (of the order of 10%). More significant deviations can be observed in special cases, which are described in the article. However, elastic moduli that are much lower than expected are sometimes seen, even in careful experiments. It now appears that this behavior may be explainable by time-dependent anelastic relaxation mechanisms. In contrast to purely elastic behavior, anelastic behavior is very sensitive to microstructure and is found to be common and often significant when things become small.

In this article, we discuss creep deformation as it relates to thin films and multilayer foils. We begin by reviewing experimental techniques for studying creep deformation in thin-film geometries, listing the pros and cons of each; then we discuss the use of deformation-mechanism maps for recording and understanding observed creep behavior. We include a number of cautionary remarks regarding the impact of microstructural stability, zero-creep stresses, and transient-creep strains on stress–strain rate relationships, and we finish by reviewing the current state of knowledge for creep deformation in thin films. This includes both thin films that are heated on substrates as well as multilayer films that are tested as freestanding foils.