Method of manufacturing high performance copper inductors with bond pads
View Patent ↗A method for manufacturing high performance copper inductors includes providing a tall, Cu laminate spiral inductor is formed at the last metal level, and at the last metal +1 level, with the metal levels being interconnected by a bar via having the same spiral shape as the spiral metal inductors at the last metal level and the last metal +1 level. The method includes integrating the formation of thick inductors with the formation of bond pads, terminals and interconnect wiring with the last metal +1 wiring. Included are dielectric deposition and spacer formation steps, and/or selective deposition of a passivating metal such as CoWP, to passivate a Cu inductor that is formed after the last metal layer.
1. A method of fabricating a high performance copper (Cu) laminate inductor comprising the steps of:
forming a last metal layer including damascene Cu interconnects in a dielectric, one Cu interconnect including a Cu laminate inductor at a last metal Cu level;
depositing one or more layers of passivation material over the last metal layer damascene Cu interconnects;
patterning terminal vias in the one or more layers of passivation material corresponding to said Cu interconnects, one terminal via including a via of the Cu laminate inductor over the last metal Cu level of the Cu laminate inductor;
forming a bond pad structure above one of said Cu interconnects including depositing metal for said bond pad and a baffler layer, patterning the metal for said bond pad and baffler layer, and depositing a Cu seed layer atop said bond pad and barrier layer;
depositing and patterning a resist for Cu inductors, and depositing Cu to selectively form Cu in inductor regions at a last metal+1 Cu level of the Cu laminate inductor over the via and the last metal Cu level, to form the Cu laminate inductor; and
stripping the resist, etching the Cu seed layer, and selectively depositing a passivating layer on said Cu inductors.
2. The method of claim 1 , further comprising forming a passivating layer over the last metal+1 Cu level of the Cu laminate inductor.
3. The method of claim 2 , further comprising forming a passivating layer of CoWP over the last metal+1 Cu level of the Cu laminate inductor.
4. The method of claim 1 , further including:
said last metal+1 level having said Cu inductors and bond pad structure with polyimide, and forming openings to said bond pad; and,
depositing barrier layer metallurgy, and forming solder balls.