Methods of forming planarized conductive interconnects for integrated circuits

摘要

A conductive planarization layer, preferably a doped polysilicon layer, is used as a planarization layer for forming a conductive interconnect, such as a memory device bit line, thereon. Etching of the doped polysilicon planarization layer may be accurately controlled to form a planarized layer of controlled thickness, without requiring high temperature reflow heating of boro-phospo-silicate glass which can degrade transistor parameters. In particular, an insulating layer is formed on spaced apart source and drain regions and on the gate therebetween. A doped polysilicon layer is formed on the insulating layer. The doped polysilicon layer is planarized. A contact hole is formed in the insulating layer and in the doped polysilicon layer, to thereby expose the source or drain region. A conductive interconnect is then formed in the contact hole and on the gate.