Method for forming inter-metal dielectrics

摘要

An improved method for forming inter-metal dielectrics (IMD) over a semiconductor substrate is provided, wherein a conductive line is formed thereon. A first dielectric layer is formed over the conductive line. A second dielectric layer is formed on the first dielectric layer by a spin-on glass method. A curing treatment with an electron beam having a low energy and a high dosage is performed to cure an upper portion of the second dielectric layer so that a cured third dielectric layer is formed on the second dielectric layer. A fourth dielectric layer is formed on the cured third dielectric layer. A chemical-mechanical polishing process is performed using the cured dielectric layer as a stop layer. A cap layer is formed on the fourth dielectric layer.