| 摘要 |
PURPOSE:To avoid the disconnection of an upper layer wiring formed onto a lower layer wiring by previously changing 1/3-2/3 of the thickness of the Al lower layer wiring into Al2O3 first when shaping multilayer wirings and shaving off Al2O3 intruding to the end section of the lower layer wiring remaining under a mask when the multilayer wirings are etched selectively by using the mask. CONSTITUTION:An insulating film 2 for insulating isolation is applied onto the surface of a semiconductor substrate 1, an Al thin-film layer 3 as a lower layer wiring is formed onto the insulating film 2, and a mask material 6, which has large adhesive properties with the layer 3 and consists of a negative type resist according to a predetermined pattern, is shaped onto the layer 3. The substrate 1 is anodized in a 2% sulfuric acid aqueous solution to convert only 1/3-2/3 of the film thickness of the layer 3 into an Al2O3 layer 7. Consequently, the layer 7 is intruded even to the end section of the layer 3 remaining under the mask material 6, and the layer 7 and the exposed layer 3 are removed by a liquid having the large etching selection ratio of Al2O3/Al. An upper wiring layer 5 is applied onto the lower wiring layer 3, the end section thereof is made gentle, through an inter-layer insulating film 4. |
