Patent ID: 6127070
Filing Date: 2000-10-03
Classification: H01L

Abstract:
A method of forming a multi-layered interconnect structure, comprising the steps of:forming a first dielectric layer on an anti-reflective coating (ARC) layer covering a first metal layer;forming a nitride layer on the dielectric layer, the nitride layer having a thickness within the range of 50 .ANG.-2000 .ANG.;forming an ultra-thin photoresist layer on the nitride layer, the ultra-thin photoresist layer having a thickness within the range of 50 .ANG.-2000 .ANG.;patterning the ultra-thin photoresist layer with short wavelength radiation to define a pattern for a via, the short wavelength radiation falling within the range of about 11 nm to 13 mn;using the ultra-thin photoresist layer as a mask during a first etch step to transfer the via pattern to the nitride layer, the first etch step including an etch chemistry that is selective to the nitride layer over the ultra-thin photoresist layer;using the nitride layer as a hard mask during a second etch step to form a contact hole corresponding to the via pattern by etching portions of the dielectric layer;filling the contact hole with a conductive material so as to form the via;removing the hard mask and planarizing the conductive material via CMP;forming a second metal layer over the via; andforming a second dielectric layer over the second metal layer.