Characterization of 8-μm period half megabit ion-implanted memory chip designs

Design and process improvements have given rise to fully functional 8-μm circuit-period ion-implanted bubble memory chips with a high degree of reproducibility in all functions at nominals and reasonably wide bias field margin ranges. Over 20 Oe bias field margin ranges on small test chips are typical. Half megabit chips of the same design have over 20 Oe bias field margin range with only 6 percent redundant loops. Packaged test chips are characterized over a wide temperature range. Good operation is achieved from -55°C to 100°C. Detailed parametic variation plots are given at -50°C and 90°C case temperatures.