A test chip using ion-implanted functions for a 16 M bit bubble memory device has been designed, fabricated and characterized. A new delineation process for ion-implanted tracks using SiO2 ion-implanted masks is effective to reduce the defects in the minor loops. As a result, bias margin of 22 Oe was obtained for minor loop bubble propagation. The test chip operation with a wide-temperature range from −25°C to 80°C has been realized.
