Magnetic bubble device processing and pickax circuit design

The processing of Permalioy field-access magnetic bubble devices will be discussed for lead-first, double level circuits emphasizing 5 μm diameter bubble circuits, but with reference to scaling down the process to 2 μm bubble diameter circuits. Device structures will be presented with typical material thicknesses and processes used for each level. A new bubble circuit based on the pickax replicator and the pickax propagation element will be introduced with emphasis on the relaxation of processing constraints that this circuit provides. Also quasi-static propagation margins for several of the key pickax elements will be presented.