To provide a capacitor-forming method of a semiconductor device that can minimize crystallization reaction in TiN for preventing roughness on a surface and at the same time can prevent Cl from being contained into a TiN film for improving characteristics in a leakage current by depositing the TiN film by an MO source by an atom layer deposition method (ALD) in the formation of an upper electrode in the structure of a metal MIS capacitor.

The capacitor-forming method of a semiconductor device includes a step for nitriding or nitriding/oxidizing the surface of a silicon substrate 100 where a lower electrode is formed by plasma to form a nitride film 120, a step for using the chemical vapor of a tantalum constituent for forming a dielectric film 140 on the nitride film 120, and a step for using an ALD method for forming the TiN film of an upper electrode 160 on the dielectric film 140.