Method and structure to improve the reliability of multilayer structures of FSG (F-doped SiO2) dielectric layers and metal layers in semiconductor integrated circuits

摘要

An improved composite dielectric structure and method of forming thereof which prevents delamination of FSG (F-doped SiO2) and allows FSG to be used as the interlevel dielectric between successive conducting interconnection patterns in multilevel integrated circuit structures has been developed. The composite dielectric structure comprises FSG, undoped silicon oxide (optional), silicon-rich silicon oxide and silicon nitride. The silicon-rich silicon oxide layer having a thickness between about 1000 and 2000 Angstroms prevents reaction of F atoms from the FSG layer with the silicon nitride layer during subsequent manufacturing heat treatment cycles and prevents the deleterious formation of delamination bubbles which cause peeling of the FSG layer.