Novel thin film field emission electron source laboratory directed research and development final report

The objective of this project was to demonstrate proof of concept of a thin film field emission electron source based on electron tunneling between discrete metal islands on an insulating substrate. An electron source of this type should be more easily fabricated permitting the use of a wider range of materials, and be less prone to damage and erratic behavior than the patterned field emitter arrays currently under development for flat panel displays and other vacuum microelectronic applications. This report describes the results of the studies of electron and light emission from such structures, and the subsequent discovery of a source of light emission from conductive paths across thin insulating gaps of the semiconductor-insulator-semiconductor (SIS) and metal-insulator-semiconductor (MIS) structures. The substrates consisted of silicon nitride and silicon dioxide on silicon wafers, Kapton{reg_sign}, quartz, and cut slabs of silica aerogels. The conductive film samples were prepared by chemical vapor deposition (CVD) and sputtering, while the MIS and SIS samples were prepared by CVD followed by cleaving, grinding, mechanical indentation, erosion by a sputter Auger beam, electrical arcing and chemical etching. Electron emission measurements were conducted in high and ultra high vacuum systems at SNL, NM as well as at SNL, CA. Optical emission measurements were made in air under an optical microscope as well as in the above vacuum environments. Sample morphology was investigated using both scanning electron microscopy (SEM) and transmission electron microscopy (TEM)