Interfacial layer formation in the vacuum-deposited aluminum/YZ lithium niobate

The vacuum-deposited Al/YZ LiNbO
3
interface has been studied by fabricating a surface acoustic wave (SAW) color-TV IF filter for the European PAL standard with 38.9-MHz vision carrier. An interfacial layer is formed whenever Al is deposited on the LiNbO
3
surface. This interfacial layer, which is attributed to the reaction product of aluminum with lithium niobate, causes the positive shift in the frequency response.