Semiconductor memory device having composite dielectric film structure and methods of forming the same

A semiconductor device, comprising:

• a substrate including a first region and a second region, wherein an upper surface of the substrate is recessed in the first region relative to an upper surface of the substrate in the second region;
• a plurality of memory devices located in the first region;
• a plurality of transistors each including a metal gate located in the second region;
• and
• a composite dielectric film structure comprising at least two dielectric layers extending over the plurality of transistors in the second region, wherein a lower surface of the composite dielectric film structure is co-planar with an upper surface of each of the memory devices.

A method of fabricating a semiconductor device, comprising:

• forming a plurality of memory devices in a first region of a substrate;
• forming a plurality of transistors, each including a metal gate, in a second region of the substrate;
• forming a first dielectric material layer over the plurality of transistors in the second region and over a portion of each of the memory devices in the first region;
• forming a second dielectric material layer over the first dielectric layer in the second region, wherein the second dielectric layer does not extend over the plurality of memory devices in the first region;
• depositing a metal material layer over the semiconductor device;
• heating the metal material layer to form a metal silicide layer over portions of the memory devices that are exposed through the first dielectric layer;
• and
• performing an etching process to remove remaining portions of the metal material layer.