公开(公告)号：DE2658133A1

公开(公告)日：1977-07-07

申请号：DE2658133

申请日：1976-12-22

Applicant: IBM

Inventor： CASTELLANI EUGENE EDWARD ,  MCCAFFREY PATRICK MICHAEL ,  PFEIFFER ALOYSIUS THEODORE ,  ROMANKIW LUBOMYR TARAS

IPC: G03F7/038 ,  G03F1/20 ,  G03F7/004 ,  H01L21/027 ,  H01L21/18

Abstract: A method of constructing a relatively thick, self-supporting mask suitable for electron beam projection processes. Thickness is achieved by multiple steps of coating with resist, exposure, development and plating. First an intermediate or lift off layer is deposited on a substrate. A plating or a cathode layer may then be deposited. Resist is then applied. A first mask layer comprises metal plated in accordance with the first pattern. For the second exposure a geometrically similar pattern is employed to generate larger apertures. Thus, if the first mask layer has 0.20 mil apertures, the second layer might have corresponding 0.21 mil to 0.22 mil apertures. For initial mask patterns of about 2 mil the second layer might be 2.02 mils. If desired, a third exposure can be employed with a third pattern, similar to the first two, but having larger apertures (by 0.02 to 0.03 mils) than the second pattern.