INTERNAL PHOTOEMISSION IN EVAPORATED AL-AL2O3-AL THIN FILM DEVICES.
Abstract
The results of a study of internal photoemission in evaporated Al-Al2O3-Al thin-film sandwiches will be presented. The dielectric films for these samples were prepared by electron-beam evaporation from a sapphire rod. This material has a dielectric constant of about 7.5. Film thicknesses were measured capacitively, interferrometrically, and with a quartz-crystal-oscillator microbalance, all of which gave internally consistent results. The photoresponse was measured at room temperature as a function of wavelength at different bias voltages for dielectric films ranging in thickness from about 100 A to less than 40 A. The results, interpreted in terms of metal-insulator barrier height, indicate that the barrier shape is trapezoidal but that the asymmetry decreases abruptly for dielectric thicknesses below about 60 A. The zero-bias barrier height was found to be 1.8 eV for the 42-A films, and it increased rapidly with dielectric thickness. These results will be discussed in terms of the current theories of metal-insulator-metal thin-film devices. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1968
- Accession Number
- AD0669331
Entities
People
- Fritz L. Schuermeyer
- Julian A. Crawford
- Kenneth D. O'dell
Organizations
- Air Force Research Laboratory