摘要:
The invention describes a method for forming a dual damascene structure. An etch stop layer (150) is formed on a dielectric layer (140). A second dielectric layer (160) is formed on the etch stop layer (150) and an oxynitride ARC layer (170) is formed the second dielectric layer. A first trench (185) is etched in the second dielectric layer (160) to a depth greater than the thickness of the second dielectric layer (160). A first trench (185) and a second trench (195) are then simultaneously formed in the first and second dielectric layers (140) and (160) respectively.