MICROFABRICATED FIELD-EMISSION AND FIELD-IONIZATION SOURCES

The application of microfabrication technology to the development of vacuum field-effect devices has led to a resurgence in vacuum technology. I describe microfabricated field-emission cathodes and field ion sources and discuss their performance characteristics. Arrays of miniaturized field electron emitters have been shown to produce current densities of hundreds of amperes per square centimeter of cold emission averaged over the area occupied by the array with applied voltages of less than 200 V, and tens of milliamperes of emission current have been produced with less than 100 V applied. We have microfabricated field ionization sources with micron-size dimensions and shown that they produce useful field ionization current from hydrocarbon samples and require less than 100 V to produce electric fields of sufficient strength to induce field ionization.