Method for forming a capacitor electrode

Abstract

A method for forming an improved embedded DRAM structure, that is formed on-chip with CMOS logic portions, begins by forming dual inlaid regions (34a through 34c). The region (34a) is a portion of a dual inlaid region which is filled with an oxidation tolerant material (e.g., iridium or ruthenium) to form a metallic plug (36a). This plug (36a) forms a storage node region for a DRAM and electrically contacts to a current electrode (26) of a DRAM pass transistor. Opening (34b) is filled concurrently with the filling of opening (34a), to form a metallic plug (36b) which forms a bit line contact for the DRAM cell. A top portion of the dual inlaid structure (34c) is filled concurrent with regions (34a and 34b) to enable formation of a bottom electrode of the ferroelectric DRAM capacitor. Since the geometry of the region (36c) is defined by dual inlaid/CMP processing, no RIE-defined sidewall of the bottom capacitor electrode is present whereby capacitor leakage current is reduced. Furthermore, the oxygen-tolerant material used to form the plugs (36a through 36c) herein prevents adverse plug oxidation which is present in the prior art during ferroelectric oxygen annealing.

Dependencies are inferred from the claim text.