MULTILAYER MIM CAPACITOR

摘要

A semiconductor capacitor and method of fabrication is disclosed. A MIM stack, having alternating first-type and second-type metal layers (each separated by dielectric) is formed in a deep cavity. The entire stack can be planarized, and then patterned to expose a first area, and selectively etched to recess all first metal layers within the first area. A second selective etch is performed to recess all second metal layers within a second area. The etched recesses can be backfilled with dielectric. Separate electrodes can be formed; a first electrode formed in said first area and contacting all of said second-type metal layers and none of said first-type metal layers, and a second electrode formed in said second area and contacting all of said first-type metal layers and none of said second-type metal layers.

主权项

1. A method to form a deep-trench capacitor comprising:
providing substrate having a stack of metal layers in a cavity, said stack comprising first-type metal layers and second-type metal layers, wherein each adjacent pair of said stack comprises one first-type metal layer and one second-type metal layer, said stack further comprising an insulating layer between said adjacent pairs; exposing a cross section of said stack; etching said first-type metal layers within a first area of said cross section while not appreciably etching said second-type metal layers; etching said second-type metal layers within a second area of said cross section while not appreciably etching said first-type metal layers.