606 銅薄膜の変形挙動

抄録

Recently, extensive effort have been made to replace aluminum by copper for the interconnect materials in the Si-ULSI devices. On the other hand, application of a lower specific inductive capacity, Low-k, material to the intermediate insulation film between copper and silicon is also a serious subject. The purpose of the present study is to assess the stress change accompanied by heating and cooling on copper films deposited on a silicon substrate with three insulation layers having different capacity, and to clarify the influence of the insulation film material on the thermal stress. The assessment was carried out by measuring the curvature of the samples during heating and cooling. As a result, tensile stress at room temperature both before and after the heat cycle was reduced, and maximum compression stress at elevated temperatures was raised, when the capacity of the insulation layer was lowered.