Substrate, lithographic multiple exposure method, machine readable medium

A method for imaging using a lithographic system includes decomposing a desired pattern to be printed on the substrate into at least two constituent sub-patterns that are capable of being optically resolved by the lithographic system, coating a substrate a substrate with a stack of two sacrificial hard masks on top of a target layer which is to be patterned with the desired dense line pattern. To provide suitable etch stop layers, the material of the sacrificial mask layers and the target layer is chosen such that for each etching step, the etching between two exposures and the etching of the target layer have alternating selectivities.