METHOD FOR FORMING METAL INTERCONNECTION OF SEMICONDUCTOR DEVICE TO IMPROVE ELECTRICAL CHARACTERISTIC OF METAL INTERCONNECTION

摘要

PURPOSE: A method for forming a metal interconnection of a semiconductor device is provided to improve an electrical characteristic of a metal interconnection by filling a metal material in contact holes with different depths. CONSTITUTION: A plurality of lower metal interconnections(12) are formed on a substrate(11) having a step in a cell region and a peripheral circuit region. After the first insulation layer(13A) is formed on the resultant structure, a plurality of the first contact holes to which the lower metal interconnections in the peripheral circuit region are formed. A metal pillar(15A) is formed in the first contact hole. The second insulation layer(13B) is formed on the resultant structure, and an interlayer dielectric(13) composed of the first and second insulation layers is formed. The interlayer dielectric is etched by an etch process until the upper end part of the metal pillar is exposed. A selected part of the interlayer dielectric is etched to form a plurality of the second contact holes to which each lower metal interconnection in the cell region is exposed. An upper metal interconnection(17) is formed.