A method is provided for forming sub-micron-size structures over a substrate. A width-defining step is formed over the substrate. A width-defining layer is formed over an edge of the width-defining step. The width-defining layer is etched back to leave a spacer adjacent the width-defining step. A length-defining step is formed over the substrate. A length-defining layer is formed over an edge of the length-defining step. The length-defining layer is etched back to leave a spacer adjacent a first edge of the length-defining step and across a first portion of the spacer left by the width-defining layer. The length-defining step is then removed. The spacer left by the width-defining layer is then etched with the spacer left by the length-defining layer serving as a mask, to form the structure.