Semiconductor device with high- and low-density regions of transistor elements on single semiconductor substrate, and method of manufacturing such semiconductor device

摘要

A semiconductor device manufacturing process for forming a semiconductor device having a high density region and a low density region of transistor elements, includes forming a gate oxide film and gate electrodes on a semiconductor substrate surface. Then, a first nitride film is uniformly formed on the gate electrodes, and only the low-density region of the semiconductor device is etched. Then, a second nitride film is uniformly formed, and then an interlayer insulating film is formed. The high-density region is self-aligned using the first nitride film as an etch stopper to form contact holes in the interlayer insulating film, and contact electrodes are formed In the contact holes. The assembly is then annealed by a forming gas to recover an interfacial layer.