An embodiment of the invention provides a semiconductor integrated circuit device having a dummy pattern for improving micro-loading effects. The device comprises an active region in a substrate and an isolation region in the substrate adjacent the active region. A plurality of dummy patterns are formed over the isolation region, wherein each dummy pattern is aligned parallel to and lengthwise dimension of the active region. The dummy patterns may have non-uniform spacing or non-uniform aspect ratios. The dummy pattern may have, in plan view, a rectangular shape, wherein its length is greater than the lengthwise dimension of the active region. The spacing between the dummy pattern and the active region may be less than about 1500 nm.