Microstructure Arrays Produced by Ion Milling

Techniques have been developed using argon ion milling to produce high-density microstructure arrays of permalloy magnetic dipoles for use in magnetic bubble devices. Ion milling is used to replace the chemical etch process in the usual photolithographic method, which results in an order-of-magnitude improvement in density. A 1000-bit I and bar shift register has been made in which the spacing between elements in 7.5μ, and the width of the elements are ∼ 1μ. The entire structure is 0.25 mm (or 10 mil) square.