| 摘要 |
PURPOSE:To check generation of a hillock on the sides of wirings, and to realize the high-density wirings at formation of the high-density wiring layer by a method wherein after the Al or Al alloy wirings are formed according to the lift-off method, high melting point metal films or insulating films are formed only on the sides of the wirings before heat treatment is to be performed, and then heat treatment is performed to obtain ohmic contact. CONSTITUTION:After respective elements are formed on a semiconductor substrate 21, the surface thereof is covered with an oxide film 22, and a photosensitive resist 33 is applied thereon. Then, Al or an Al alloy 25 is adhered to form a film on the whole surface of the semiconductor substrate 21 having the formed pattern 24 of the photosensitive resist using well-known exposure technique. When the substrate thereof is immersed inn an organic solvent, wirings 26 consisting of the remaining Al or Al alloy 25 are completed, and a high melting point metal film 27 consisting of W, Ta, Wo, etc. is adhered to form a film as to cover the wirings thereof. When anisotropically reactive ion etching is performed next, high melting point metal films 27 are left only on the sides of the wirings 26. Heat treatment at 400-500 deg.C is performed in this condition to obtain ohmic contact at the contact parts between the wirings 26 and the semiconductor substrate 21.
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