PROCESS OF ULTRA THICK TRENCH ETCH WITH MULTI-SLOPE PROFILE

摘要

The present disclosure relates to an integrated chip (IC) having an ultra-thickmetal layer formed in a metal layer trench having a rounded shape that reduces stress between an inter-level dielectric (ILD) layer and an adjacent metal layer, and a related formation method. In some embodiments, the IC has an inter-level dielectric layer disposed above a semiconductor substrate. The ILD layer has a cavity with a sidewall having a plurality of sections, wherein respective sections have different slopes that enable the cavity to have a rounded shape. A metal layer is disposed within the cavity. The rounded shape of the cavity reduces stress between the ILD layer and the metal layer to prevent cracks from forming along an interface between the ILD layer and the metal layer.