Interconnect structure and method of forming same

摘要

A method of forming a semiconductor device is provided. Metallic interconnects are formed in a dielectric layer of the semiconductor device. A hard mask is used to avoid usual problems faced by manufacturers, such as possibility of bridging different conductive elements and via patterning problems when there are overlays between vias and trenches. The hard mask is etched multiple times to extend via landing windows, while keeping distance between the conductive elements to avoid the bridging problem.

主权项

1. A method for forming a semiconductor device, the method comprising:
forming a first dielectric layer over a substrate; forming a second dielectric layer over the first dielectric layer; forming a mask layer over the second dielectric layer; patterning the mask layer to form a patterned mask layer, the patterned mask layer having a first opening therein, the patterning forming a first recess in the second dielectric layer; patterning the patterned mask layer to widen the first opening, the patterning forming a second recess and a third recess in the second dielectric layer, the third recess being formed within the first recess, the third recess having a depth greater than the first recess and the second recess; forming a fourth recess at least partially overlapping the third recess, the fourth recess extending into the first dielectric layer; extending the first recess, the second recess, and the third recess into the first dielectric layer and extending the fourth recess through the first dielectric layer, thereby forming a second opening in the first dielectric layer; and forming a conductive feature in the second opening in the first dielectric layer.