Abstract: An improved method of lift-off processing semiconductor devices including ohmic electrodes, gate electrodes, metal wiring, and the like. The invention provides for the production of an access groove pattern in the surface of the substrate prior to the application of the resist by photolithography and the deposition of metallization. The access groove pattern increases the opportunity for the chemical stripper to dissolve the resist and lift away the unrequired portions of the metallization, thus improving the reliability of the lift-off.

Abstract: A method for manufacturing a semiconductor integrated circuit device having contact apertures with finely-controlled dimensions of 1 .mu.m or less. An ion bombardment layer is formed by bombarding predetermined portions of the substrate of the semiconductor device with nitrogen ions using a direct ion beam imaging technique. The ion bombardment layer is converted into an oxidation-resistant layer by annealing, and an insulating oxide layer is formed on the surface of the substrate in regions other than those on which the oxidation-resistant layer is formed by oxidation. Thereafter, contact recesses are formed upon removing the oxidation-resistant layer.

Abstract: Ions of a metal which becomes passive under the presence of oxygen with regard to plasma etching are implanted into selected portions of the surface of a workpiece, after which the workpiece is subjected to plasma etching with a reaction gas mixed with oxygen, whereby that layer which has been rendered passive acts as a mask, and an etched pattern is formed.