US Patent 11688636 Spin on scaffold film for forming topvia

A method of manufacturing a semiconductor device is provided. The method includes forming a plurality of metal lines on substrate, forming a sacrificial dielectric material layer between the metal lines, forming a hardmask over at least one of the metal lines, etching at least one of the metal lines that is not covered by the hardmask, treating the sacrificial dielectric material layer to soften the layer. The method also includes removing the treated sacrificial dielectric material layer.