Ferroelectrics, microsystems and nanotechnology

The term 'Nanotechnology' was first coined by Taniguchi in 1974 to describe the precision manufacture of mechanical parts with finishes and tolerances in the nanometer region. However, the term has now expanded in its meaning to cover the definition and exploitation of entities (materials, devices etc) in which there is a dimension of less than 100 nm which is critical to their performances or behaviour. It covers a wide range of activities from ultra-precision engineering and fine-line lithography through nanostructured materials to the use of microsystems for fabricating and manipulating materials on the nanoscale. This talk will review the subject of nanotechnology and explore how new materials can be used to integrate sensing and actuation functions onto semiconductor chips, with the ultimate objective of permitting nanoscale fabrication and information storage. Ferroelectric materials offer a wide range of properties which can be used in such microsystems and nanotechnology, particularly the pyroelectric effect for thermal infra-red detection and imaging and the piezoelectric effect for sensors (sound, acceleration etc), and for actuators (motors, pumps). The potential for ferroelectric thin and thick films to contribute to these fields will be discussed, and problems reviewed, especially from the aspect of materials and process integration. Specific examples of the factors critical to the growth and behaviour of the materials will be given and novel processed for the fabrication of thin and thick films of ferroelectrics discussed.