Dual damascene process using high selectivity boundary layers

摘要

A method of manufacturing a semiconductor device with multiple dual damascene structures that maintains the maximum density. A first dual damascene structure having a first via and a first trench is formed in a first interlayer dielectric and a first etch stop layer formed on the planarized surface of the first interlayer dielectric. Two layers of interlayer dielectric separated by a second etch stop layer is formed on the surface of the first etch stop layer. A third etch stop layer is formed on the upper layer of interlayer dielectric and a first photoresist layer formed on the third etch stop layer. The photoresist layer is etched having a dimension coinciding with a width dimension of the first via. The third etch stop layer is selectively etched and the first photoresist layer removed and replaced by a second photoresist layer. The second photoresist layer is etched having a dimension coinciding with a width dimension of the first trench. The two layers of interlayer dielectric and the first, second and third etch stop layers are etched to form a second dual damascene structure having a second via and a second trench having the same dimensions as the first dual damascene structure.