Ion beam milling combined with improved lithography will permit the etching of fine line circuits with controlled wall shapes in a wide variety of materials. This dry process has been used in the laboratory for several years and is now finding acceptance in the production of bubble memory devices and MOS circuitry. This paper will review the important characteristics of ion beam etching and comment on the state of the art in mass production equipment. The main difference between ion beam etching and conventional sputter etching is the use of a directed ion beam and a work chamber at a relatively low pressure. These differences produce four chief advantages. First, the low pressure results in less contamination and poisoning and, second, the directed beam permits control of the etching profile. Third, one can independently select the ion current, voltage, and pressure for reproducible results over a wide range of values. Fourth, the net charge of the positive ions can be balanced by low energy electrons, allowing the etching of any insulator or conductor. An organic or metal mask is utilized to pattern the material being etched. Typical removal rates in large batch processes range from 300 to 400 Å/min. Submicron soaced lines can be etched with either straight or sloped walls.