A method is described. A substrate is provided. A first conductive layer with a first width and a second conductive layer with a second width are formed on the substrate. Photolithography and etching processes are performed on the dielectric layer to at least expose a first region of the first conductive layer and a second region of the second conductive layer. An oxide layer is then formed over the dielectric layer and the exposed first and second conductive layers. The method of applying partial reverse mask is able to resolve the adhesion problem of the dielectric layer with low dielectric constant.