256 kbit bubble memory chip fabrication and characterization

A 256 kbit bubble memory chip, which uses asymmetric chevron propagation elements has been designed, fabricated and characterized. Average circuit period is 8 μm and minimum feature size is 1 μm for all chip functions. Chip size is 4.5 mm×5.1 mm. A new stretcher detector and a planar chip structure enable the 256 kbit chip to operate at low rotating field. For a typical device processed on a (YSmLu)3(FeGa)5O12 magnetic garnet film, the overall bias margin for all functions is 15 Oe with a 50 Oe circular rotating field at 200 kHz.