Semiconductor device and a method of manufacturing the same

Abstract

A technique is provided for improving the security of information stored in a semiconductor device. Multilayer wiring layers are formed over a semiconductor substrate. Wirings are formed on the uppermost wiring layer among those multilayer wiring layers. On the wirings, there is formed, in the following order, a silicon oxide film, a colored thin film, and a silicon oxide film, over which, a silicon nitride film serving as a surface protective film is formed. In other words, the invention is characterized by that the colored thin film is formed between the wiring constituting the uppermost wiring layer and the silicon nitride film serving as the surface protective film. The colored thin film has a function of attenuating visible light and laser light in the specific wavelength region, and is formed of, for example, a silicon oxide film containing cobalt oxide.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an entire plan view showing an IC card according to a first preferred embodiment of the invention;

FIG. 2 is a sectional view taken along the line A-A of FIG. 1;

FIG. 3 is a sectional view showing a modified example of FIG. 2;

FIG. 4 is a top view showing a layout structure of respective elements formed in a semiconductor chip;

FIG. 5 is a sectional view showing a section of a semiconductor device of the first embodiment;

FIG. 6 is a sectional view showing a manufacturing step of the semiconductor device of the first embodiment;

FIG. 7 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 6;

FIG. 8 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 7;

FIG. 9 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 8;

FIG. 10 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 9;

FIG. 11 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 10;

FIG. 12 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 11;

FIG. 13 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 12;

FIG. 14 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 13;

FIG. 15 is a flowchart for explaining steps of forming a colored thin film;

FIG. 16 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 14;

FIG. 17 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 16;

FIG. 18 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 17;

FIG. 19 is a sectional view showing a section of a semiconductor device according to a second preferred embodiment of the invention;

FIG. 20 is a sectional view showing a manufacturing step of the semiconductor device of the second embodiment;

FIG. 21 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 20;

FIG. 22 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 21;

FIG. 23 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 22;

FIG. 24 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 23;

FIG. 25 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 24;

FIG. 26 is a sectional view showing a modified example of the second embodiment;

FIG. 27 is a sectional view showing another modified example of the second embodiment;

FIG. 28 is a sectional view showing a manufacturing step of a semiconductor device according to a third preferred embodiment of the invention;

FIG. 29 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 28;

FIG. 30 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 29;

FIG. 31 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 30;

FIG. 32 is a sectional view showing a semiconductor device according to a fourth preferred embodiment of the invention;

FIG. 33 is a sectional view showing a manufacturing step of the semiconductor device of the fourth preferred embodiment;

FIG. 34 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 33;

FIG. 35 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 34; and

FIG. 36 is a sectional view showing a manufacturing step of the semiconductor device, following the step of FIG. 35.

Claims

1. A semiconductor device comprising: (a) an uppermost wiring layer formed over a semiconductor substrate;(b) an interlayer insulating film formed over the uppermost wiring layer; and(c) a surface protective film formed over the interlayer insulating film,wherein a colored thin film for attenuating visible light and laser light in a specific wavelength region is formed in or at the interlayer insulating film.

2. The semiconductor device according to claim 1, wherein the colored thin film is an insulating film.

3. The semiconductor device according to claim 1, wherein the colored thin film is a conductive film.

4. The semiconductor device according to claim 2, wherein the colored thin film has a thickness of 100 nm or more and 2 μm or less.

5. The semiconductor device according to claim 2, wherein the colored thin film is formed of a silicon oxide film containing a metal oxide.

6. The semiconductor device according to claim 5, wherein the silicon oxide film is a SOG (Spin On Glass) film.

7. The semiconductor device according to claim 6, wherein the metal oxide is cobalt oxide.

8. The semiconductor device according to claim 3, wherein the colored thin film is formed of a graphite film.

9. The semiconductor device according to claim 8, wherein the graphite film has a thickness of 30 nm or more and 50 nm or less.

10. The semiconductor device according to claim 1, wherein the colored thin film is adapted to attenuate the laser light having a wavelength of 500 nm or more and 600 nm or less.

11. A semiconductor device comprising: (a) a first wiring layer formed over a semiconductor substrate;(b) an interlayer insulating film formed over the first wiring layer; and(c) a second wiring layer formed over the interlayer insulating film,wherein a colored thin film for attenuating visible light and laser light in a specific wavelength region is formed in or at the interlayer insulating film.

12. A semiconductor device comprising: (a) a MISFET (metal-insulator-semiconductor field-effect transistor) formed over a semiconductor substrate;(b) an interlayer insulating film formed over the MISFET; and(c) a wiring layer formed over the interlayer insulating film,wherein a colored thin film for attenuating visible light and laser light in a specific wavelength region is formed in or at the interlayer insulating film.

13. A semiconductor device comprising: (a) an interlayer insulating film formed over a semiconductor substrate; and(b) an embedded wire formed to be embedded into the interlayer insulating film,wherein a colored thin film for attenuating visible light and laser light in a specific wavelength region is formed in or at the interlayer insulating film.

14. A semiconductor device comprising: (a) a first interlayer insulating film formed over a semiconductor substrate;(b) a wiring formed over the first interlayer insulating film; and(c) a second interlayer insulating film formed over the wiring,wherein a colored thin film for attenuating visible light and laser light in a specific wavelength region is formed in or at each of the first and second interlayer insulating films.

15. A semiconductor device comprising: (a) an uppermost wiring layer formed over a semiconductor substrate;(b) an interlayer insulating film formed over the uppermost wiring layer; and(c) a surface protective film formed over the interlayer insulating film,wherein a thin film for attenuating light in a specific wavelength region is formed in or at the interlayer insulating film.

16. The semiconductor device according to claim 15, wherein the thin film is formed of a plurality of films having different refractive indexes.

17. The semiconductor device according to claim 16, wherein the thin film is formed of a laminated film including a silicon oxide film and a silicon carbide film.

18. A method of manufacturing a semiconductor device, comprising the steps of: (a) forming a wiring layer over a semiconductor substrate;(b) forming an interlayer insulating film over the wiring layer; and(c) forming a surface protective film over the interlayer insulating film,wherein the (b) step comprises the step of:(d) forming a colored thin film for attenuating visible light and laser light in a specific wavelength region.

19. The method according to claim 18, wherein the (d) step comprises the sub-steps of: (d1) mixing a metal oxide into a solution containing silica;(d2) applying to the semiconductor substrate the solution into which the metal oxide is mixed; and(d3) forming a silicon oxide film containing the metal oxide by applying heat treatment to the semiconductor substrate to evaporate solvent in the solution.

20. The method according to claim 19, wherein the metal oxide is cobalt oxide.

21. The method according to claim 18, wherein the colored thin film is a graphite film formed by a plasma CVD (Chemical Vapor Deposition) method.

22. A method of manufacturing a semiconductor device, comprising the steps of: (a) forming a first wiring layer over a semiconductor substrate;(b) forming an interlayer insulating film over the first wiring layer; and(c) forming a second wiring layer over the interlayer insulating film,wherein the (b) step comprises the step of forming a colored thin film for attenuating visible light and laser light in a specific wavelength region.

23. A method of manufacturing a semiconductor device, comprising the steps of: (a) forming a wiring layer over a semiconductor substrate;(b) forming an interlayer insulating film over the wiring layer; and(c) forming a surface protective film over the interlayer insulating film,wherein the (b) step comprises the step of:(d) forming a thin film for attenuating light in a specific wavelength region.

24. The method according to claim 23, wherein the (d) step involves forming a laminated film including films with different refractive indexes.

25. The method according to claim 24, wherein the (d) comprises the sub-steps of: (d1) forming a silicon oxide film; and(d2) forming a silicon carbide film whose refractive index is different from that of the silicon oxide film, over the silicon oxide film.