Semiconductor device and manufacturing method thereof

• US 20070232004A1
• Filed: 09/11/2006
• Published: 10/04/2007
• Est. Priority Date: 03/30/2006
• Status: Active Grant

• Current Assignee: Socionext Inc.
• Original Assignee: Fujitsu Limited
• Inventors: Sakoda, Tsunehisa, Ikeda, Kazuto
• Granted Patent: US 7,893,508 B2
• Time in Patent Office: Days
• US Class Current: 438/287
• CPC Class Codes: H01L 21/28194 by deposition, e.g. evaporation, ALD, CVD, sputtering, laser deposition H01L21/28202 takes precedence
• CPC Class Codes: H01L 21/28202 in a nitrogen-containing ambient, e.g. nitride deposition, growth, oxynitridation, NH3 nitridation, N2O oxidation, thermal nitridation, RTN, plasma nitridation, RPN
• CPC Class Codes: H01L 29/513 the variation being perpendicular to the channel plane
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence

Abstract

A semiconductor device capable of suppressing a threshold shift and a manufacturing method of the semiconductor device. On a high dielectric constant insulating film, a diffusion barrier film for preventing the diffusion of metal elements from the high dielectric constant insulating film to an upper layer is formed. Therefore, the diffusion of the metal elements from the high dielectric constant insulating film to the upper layer can be prevented. As a result, a reaction and bonding between the metal elements and a Si element in a gate electrode can be suppressed near a boundary between an insulating film and the gate electrode.

Claims

1. A semiconductor device having a high dielectric constant insulating film in a gate section, comprising:

a diffusion barrier film for preventing the diffusion of metal elements from the high dielectric constant insulating film to an upper layer, the film being formed on the high dielectric constant insulating film;

an insulating film formed on the diffusion barrier film; and

a gate electrode formed on the insulating film.

2. The semiconductor device according to claim 1, wherein:

the high dielectric constant insulating film is made of an oxide film, oxynitride film or nitride film which contains at least one of hafnium, aluminum, zirconium, yttrium, lanthanum and tantalum.

3. The semiconductor device according to claim 1, wherein:

the diffusion barrier film is made of a silicon nitride, aluminum nitride or hafnium nitride film.

4. The semiconductor device according to claim 3, wherein:

a thickness of the diffusion barrier film is set to 0.2 to 0.5 nm.

5. The semiconductor device according to claim 1, wherein:

the insulating film is made of an oxide film, oxynitride film or nitride film which contains silicon as well as contains at least one of hafnium, aluminum, zirconium, yttrium, lanthanum and tantalum.

6. The semiconductor device according to claim 1, wherein:

the insulating film has a silicon composition larger than that of the high dielectric constant insulating film.

7. A manufacturing method of a semiconductor device having a high dielectric constant insulating film in a gate section, comprising the steps of:

forming on the high dielectric constant insulating film a diffusion barrier film for preventing the diffusion of metal elements from the high dielectric constant insulating film to an upper layer;

forming an insulating film on the diffusion barrier film; and

forming a gate electrode on the insulating film.

8. The manufacturing method according to claim 7, further comprising, before the step of forming the diffusion barrier film, the step of:

performing nitriding on the high dielectric constant insulating film.

9. The manufacturing method according to claim 7, wherein:

the high dielectric constant insulating film is made of an oxide film, oxynitride film or nitride film which contains at least one of hafnium, aluminum, zirconium, yttrium, lanthanum and tantalum.

10. The manufacturing method according to claim 7, wherein:

the diffusion barrier film is made of a silicon nitride, aluminum nitride or hafnium nitride film.

11. The manufacturing method according to claim 10, wherein:

a thickness of the diffusion barrier film is set to 0.2 to 0.5 nm.

12. The manufacturing method according to claim 7, wherein:

the diffusion barrier film is formed by a MOCVD method or an ALD method.

13. The manufacturing method according to claim 7, wherein:

the insulating film is made of an oxide film, oxynatride film or nitride film which contains silicon as well as contains at least one of hafnium, aluminum, zirconium, yttrium, lanthanum and tantalum.

14. The manufacturing method according to claim 7, wherein:

the insulating film has a silicon composition larger than that of the high dielectric constant insulating film.