Abstract: An improved method for the etch-back planarization of interlevel dielectric layers provides for cessation of the etch-back upon exposure of an indicator layer. the indicator layer, usually a metal, metal nitride, or silicon nitride is formed either within the dielectric or over an underlying metallization layer prior to patterning by conventional photolithographic techniques. A sacrificial layer, typically an organic photoresist, is then formed over the dielectric layer. Because of the presence of both relatively narrow and relatively broad features in the metallization, the thickness of the sacrificial layer will vary over features having different widths. As etch back planarization proceeds, the indicator layer which is first encountered releases detectable species into the planarization reactor. Detection of these species indicates that removal of the overlying dielectric layers to a predetermined depth is achieved.

Abstract: A method for planarizing an insulating layer overlying an irregular topographic substrate, e.g., a conductive layer, is planarized by use of a sacrificial planarization layer. The planarization layer is removed using an oxygen-containing plasma generated in a parallel electrode reactor operating at a low excitation frequency and high pressure. Once the interface between the planarization layer and the conductive layer is reached, a second plasma with a reduced oxygen content is employed to avoid overetching the planarization layer. It has been observed that oxidizing species liberated during the etching of the insulating layer, typically silicon dioxide, contribute to the oxidation and hence removal of the planarization layer.