New single-mask approach to bubble device fabrication

Permalloy devices with two separate levels of fine permalloy and conductor patterns have been fabricated by the use of a single-mask process. This process makes possible the production of devices having an essentially conventional design in addition to a completely planar structure. The features of this new process include 1) preparation of a reticle on which patterns for both permalloy and conductor layers are superimposed, 2) use of SiO
2
, Mo/Au/Mo, SiO
2
, permalloy, and TiO
2
thin films deposited sequentially on the bubble materials, and 3) simultaneous delineation of both photoresist patterns with two different thicknesses and of the desired patterns by CF
4
plasma etching and ion-milling.