Control of the (111) Orientation in Copper Interconnection Layer

Abstract

Low sheet resistance copper conductive layer has been used extensively in logic large scale integrated circuits. High density current can be flowed under the high stress field. Higher electromigration resistance is another promising point in the copper conductive layer. 1,2 Deposition of thick copper conductive layer with high ~111! orientation and with low stress is required in the copper conductive layer. 3 It has recently been reported that resistivity of the electroplating copper layer is determined mainly by the grain growth of ~111! and by the stress with barrier layer 4 rather than by the impurity in the copper layer. Adhesion strength of thick copper conductive layer and agglomeration of the copper seed layer are also influenced by the ~111! orientation and by the stress of seed layer as reported elsewhere. 5,6 Although the control of the ~111! orientation is very important in the copper conductive layer, few papers have reported the control of ~111! orientation in the electroplating layer. This paper describes the control of ~111! orientation in electroplating copper layer.