Advantages and special considerations in fabricating bubble circuits by electroplating and sputter etching

A technology which has been used to fabricate a 1024 bit bubble domain memory with micron dimensions is described. The process uses additive electroplating through photoresist masks to form the propagation patterns and conductors, and sputter etching to define the magnetoresistive sensor elements. Critical aspects of the process pertinent to both dimensional control and to preservation of the properties of existing magnetic material in the structure during subsequent processing are discussed. Results are cited indicating the applicability of these processes to submicron dimensions.