SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME

Abstract

A method of manufacturing a semiconductor device according to the present invention includes the steps of introducing first impurities of a first conductivity type into a main surface of a semiconductor substrate 1 to form a first impurity region, introducing second impurities of a second conductivity type to form a second impurity region, forming a first nickel silicide film on the first impurity region and forming a second nickel silicide film on the second impurity region, removing an oxide film formed on each of the first and second nickel silicide films by using a mixed gas having an NH3 gas and a gas containing a hydrogen element mixed therein, and forming a first conducting film on the first nickel silicide film and forming a second conducting film on the second nickel silicide film, with the oxide film removed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross section of a semiconductor device according to a first embodiment.

FIG. 2 is an enlarged cross section of a neighborhood of a contact portion.

FIG. 3 is an enlarged cross section of a neighborhood of a contact portion.

FIG. 4 is a cross section of the semiconductor device at a cross-sectional position different from that shown in FIG. 2.

FIG. 5 is an enlarged cross section of an nMOS transistor and a pMOS transistor.

FIG. 6 is a cross section showing a first step of the steps of manufacturing the semiconductor device according to the first embodiment.

FIG. 7 is a cross section showing a second step of the steps of manufacturing the semiconductor device according to the first embodiment.

FIG. 8 is a cross section showing a third step of the steps of manufacturing the semiconductor device according to the first embodiment.

FIG. 9 is a cross section showing a fourth step of the steps of manufacturing the semiconductor device according to the first embodiment.

FIG. 10 is a cross section showing a fifth step of the steps of manufacturing the semiconductor device according to the first embodiment.

FIG. 11 is a cross section showing a sixth step of the steps of manufacturing the semiconductor device according to the first embodiment.

FIG. 12 is a cross section showing a seventh step of the steps of manufacturing the semiconductor device according to the first embodiment.

FIG. 13 is a cross section showing an eighth step of the steps of manufacturing the semiconductor device according to the first embodiment.

FIG. 14 is a cross section showing a ninth step of the steps of manufacturing the semiconductor device according to the first embodiment.

FIG. 15 is a cross section showing a tenth step of the steps of manufacturing the semiconductor device according to the first embodiment.

FIG. 16 is a cross section showing an eleventh step of the steps of manufacturing the semiconductor device according to the first embodiment.

FIG. 17 is a cross section at a position different from that in FIG. 16.

FIG. 18 is a cross section showing a twelfth step of the steps of manufacturing the semiconductor device according to the first embodiment.

FIG. 19 is a cross section at a position different from that in FIG. 18.

FIG. 20 is a graph showing a distribution of oxygen elements permeating into a semiconductor substrate.

FIG. 21 is a cross section showing a modification of the semiconductor device according to the first embodiment.

FIG. 22 is a cross section of a portion of the semiconductor device according to a second embodiment, where an nMOS transistor is located.

FIG. 23 is a cross section of a portion of the semiconductor device according to the second embodiment, where a pMOS transistor is located.

FIG. 24 is cross section showing in detail a conducting film that forms a barrier metal.

FIG. 25 is a cross section showing a step of manufacturing the semiconductor device according to the second embodiment, after a step corresponding to the tenth step for the semiconductor device according to the first embodiment.

FIG. 26 is a cross section of the portion where the pMOS transistor is located, in the manufacturing step shown in FIG. 25.

FIG. 27 is a cross section showing a step of manufacturing the semiconductor device according to the second embodiment, after the manufacturing step shown in FIG. 25.

FIG. 28 is a cross section showing a step of manufacturing the semiconductor device according to the second embodiment, after the manufacturing step shown in FIG. 26.

FIG. 29 is a cross section showing a step of manufacturing the semiconductor device according to the second embodiment, after the manufacturing step shown in FIG. 27.

FIG. 30 is a cross section showing a step of manufacturing the semiconductor device according to the second embodiment, after the manufacturing step shown in FIG. 28.

Claims

1. A method of manufacturing a semiconductor device, comprising the steps of: introducing first impurities of a first conductivity type into a main surface of a semiconductor substrate to form a first impurity region;introducing second impurities of a second conductivity type into the main surface of said semiconductor substrate to form a second impurity region, the second conductivity type being different from the first conductivity type;forming a first nickel silicide film on said first impurity region and forming a second nickel silicide film on said second impurity region;removing an oxide film formed on each of said first and second nickel silicide films by using a mixed gas having an NF3 gas and a gas containing a hydrogen element mixed therein; andforming a first conducting film on said first nickel silicide film and forming a second conducting film on said second nickel silicide film, with said oxide film removed.

2. The method of manufacturing the semiconductor device according to claim 1, wherein the step of removing said oxide film and the step of forming said first conducting film and forming said second conducting film are performed in the same processing room.

3. The method of manufacturing the semiconductor device according to claim 1, further comprising the steps of transporting said semiconductor substrate to a second processing room after said oxide film is removed in a first processing room, by allowing a protective film capable of suppressing oxidation of a surface of each of said first nickel silicide film and said second nickel silicide film to be left on each of said first nickel silicide film and said second nickel silicide film, the second processing room being different from the first processing room,removing said protective film in said second processing room after said semiconductor substrate is transported thereto, andforming said first conducting film and said second conducting film after said protective film is removed.

4. The method of manufacturing the semiconductor device according to claim 1, wherein said gas containing the hydrogen element is any of NH3, HF, and H2.

5. The method of manufacturing the semiconductor device according to claim 1, wherein said oxide film formed on each of said first nickel silicide film and said second nickel silicide film is removed in a plasma atmosphere.

6. The method of manufacturing the semiconductor device according to claim 1, further comprising the step of using any of a mixed gas containing an NF3 gas and an HF gas, a mixed gas containing the NF3 gas and an H2 gas, and a mixed gas containing the NF3 gas and an NH3 gas, to form a first oxidation-resistant film on said first impurity region and form a second oxidation-resistant film on said second impurity region, wherein said first and second nickel silicide films are formed after said first and second oxidation-resistant films are removed.

7. A method of manufacturing a semiconductor device, comprising the steps of: introducing first impurities of a first conductivity type into a first semiconductor layer formed on a main surface of a semiconductor substrate to form a first gate electrode;introducing second impurities of a second conductivity type into a second semiconductor layer formed on the main surface of said semiconductor substrate to form a second gate electrode, the second conductivity type being different from said first conductivity type;forming a first nickel silicide film on said first gate electrode and forming a second nickel silicide film on said second gate electrode;using a mixed gas having an NH3 gas and a gas containing a hydrogen element mixed therein to remove an oxide film formed on each of said first and second nickel silicide films; andforming a first conducting film on said first nickel silicide film and forming a second conducting film on said second nickel silicide film, with said oxide film removed.

8. A semiconductor device, comprising: a first impurity region formed in a first portion of a main surface of a semiconductor substrate;a second impurity region formed in a second portion of the main surface of said semiconductor substrate;a first nickel silicide film formed on the first portion of the main surface of said semiconductor substrate, said first impurity region being located in the first portion; anda second nickel silicide film formed on the second portion of the main surface of said semiconductor substrate, said second impurity region being located in the second portion, whereina difference between a thickness of said first nickel silicide film and a thickness of said second nickel silicide film is set to be at most 10 nm.

9. The semiconductor device according to claim 8, further comprising a first conducting film formed on said first nickel silicide film, anda second conducting film formed on said second nickel silicide film, whereina difference between a thickness of said first nickel silicide film under a first contact portion between said first conducting film and said first nickel silicide film, and a thickness of said first nickel silicide film on a periphery of said first contact portion is set to be at most 10 nm, anda difference between a thickness of said second nickel silicide film under a second contact portion between said second conducting film and said second nickel silicide film, and a thickness of said second nickel silicide film on a periphery of said second contact portion is set to be at most 10 nm.

10. A semiconductor device, comprising: a first gate electrode formed on a main surface of a semiconductor substrate and having first impurities of a first conductivity type introduced thereinto;a second gate electrode formed on the main surface of said semiconductor substrate and having second impurities of a second conductivity type introduced thereinto, the second conductivity type being different from said first conductivity type;a first nickel silicide film formed on said first gate electrode;a second nickel silicide film formed on said second gate electrode;a first conducting film formed on said first nickel silicide film; anda second conducting film formed on said second nickel silicide film, whereina difference between a thickness of said first nickel silicide film and a thickness of said second nickel silicide film is set to be at most 10 nm.

11. The semiconductor device according to claim 10, wherein a difference between a thickness of said first nickel silicide film under a first contact portion between said first nickel silicide film and said first conducting film, and a thickness of said first nickel silicide film on a periphery of said first contact portion is set to be at most 10 nm, anda difference between a thickness of said second nickel silicide film under a second contact portion between said second nickel silicide film and said second conducting film, and a thickness of said second nickel silicide film on a periphery of said second contact portion is set to be at most 10 nm.

12. A method of manufacturing a semiconductor device, comprising the steps of: forming a semiconductor layer at a first portion of a main surface of a semiconductor substrate;forming an impurity region by introducing impurities into a second portion of the main surface of said semiconductor substrate, the second portion being adjacent to said semiconductor layer, and forming a gate electrode by introducing said impurities into said semiconductor layer;forming a first insulating film on each of both side surfaces of said gate electrode;forming a first nickel silicide film on said impurity region and forming a second nickel silicide film on said gate electrode;forming a second insulating film covering said gate electrode and said impurity region;etching said second insulating film to expose a region extending from an upper side of said first nickel silicide film to an upper side of said second nickel silicide film;using any of a mixed gas having an NF3 gas and a gas containing a hydrogen element mixed therein and a mixed gas having an NH3 gas and the gas containing the hydrogen element to remove an oxide film formed on each of said first and second nickel silicide films; andforming a conducting film extending from said first nickel silicide film to said second nickel silicide film.

13. A method of manufacturing a semiconductor device, comprising the steps of: forming a first semiconductor layer and a second semiconductor layer at a first portion and a second portion, respectively, of a main surface of a semiconductor substrate;introducing first impurities of a first conductivity type into a third portion of the main surface of said semiconductor substrate to form a first impurity region, the third portion being adjacent to said first semiconductor layer;introducing said first impurities into said first semiconductor layer to form a first gate electrode;introducing second impurities of a second conductivity type into a fourth portion of the main surface of said semiconductor substrate to form a second impurity region, the fourth portion being adjacent to said second semiconductor layer, and the second conductivity type being different from said first conductivity type;introducing said second impurities into said second semiconductor layer to form a second gate electrode;forming a first insulating film on each of both side surfaces of said first gate electrode and forming a second insulating film on each of both side surfaces of said second gate electrode;forming a first nickel silicide film on said first impurity region and forming a second nickel silicide film on said second impurity region;forming a third nickel silicide film on said first gate electrode and forming a fourth nickel silicide film on said second gate electrode;forming a third insulating film covering said first and second gate electrodes and said first and second impurity regions;etching said third insulating film to expose a region extending from an upper side of said first nickel silicide film to an upper side of said third nickel silicide film and expose a region extending from an upper side of said second nickel silicide film to an upper side of said fourth nickel silicide film;using any of a mixed gas having an NF3 gas and a gas containing a hydrogen element mixed therein and a mixed gas having an NH3 gas and the gas containing the hydrogen element mixed therein to remove an oxide film formed at each of said first, second, third, and fourth nickel silicide films;forming a first conducting film extending from the upper side of said first nickel silicide film to the upper side of said third nickel silicide film; andforming a second conducting film extending from the upper side of said second nickel silicide film to the upper side of said fourth nickel silicide film.

14. The method of manufacturing the semiconductor device according to claim 13, wherein said first and second conducting films are formed at a temperature lower than a transition temperature of said first, second, third, and fourth nickel silicide films.

15. The method of manufacturing the semiconductor device according to claim 13, further comprising the step of nitriding a surface of each of said first and second conducting films.

16. A semiconductor device, comprising: a gate electrode formed on a first portion of a main surface of a semiconductor substrate;an impurity region formed in a second portion of the main surface of said semiconductor substrate, the second portion being adjacent to said gate electrode;a first nickel silicide film formed on said impurity region;a second nickel silicide film formed on said gate electrode; anda conducting film extending from an upper side of said first nickel silicide film to an upper side of said second nickel silicide film, whereinas to a thickness of said conducting film in a direction of a normal to a surface of said conducting film, a difference between the thickest portion and the thinnest portion of said conducting film is set to be at most 10 nm.