| 摘要 |
PURPOSE: A method for forming an air gap in a process for fabricating a semiconductor metal line is provided to form a stable air gap and efficiently improve an RC delay by simultaneously forming a metal interconnection and a via interconnection and by embodying low capacitance while using a conventional material. CONSTITUTION: After a lower metal interconnection(202) is formed on a lower insulation layer, an upper insulation layer is formed on the lower metal interconnection. After a photoresist layer for a contact plug is patterned on the upper insulation layer, the upper insulation layer is etched until the lower metal interconnection is exposed. The photoresist layer for the contact plug is removed. A conductor for the contact plug is filled in the etched upper insulation layer and the upper insulation layer is eliminated. After a photoresist layer for a lower metal is patterned on the conductor for the contact plug from which the upper insulation layer is removed, the lower metal interconnection is etched until the lower insulation layer is exposed. After the photoresist layer for the lower metal is eliminated, an IMD(intermetal dielectric)(212) is deposited to form an air gap(214). The IMD is planarized by a CMP(chemical mechanical polishing) process, and an upper metal interconnection(216) is deposited.
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