Solid-state image sensor and method of fabricating the same

• US 20020009823A1
• Filed: 10/03/2001
• Published: 01/24/2002
• Est. Priority Date: 08/27/1998
• Status: Active Grant

• Current Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Original Assignee: NEC Corporation
• Inventors: Nakashiba, Yasutaka, Nagata, Tsuyoshi
• Granted Patent: US 6,703,256 B2
• Time in Patent Office: Days
• US Class Current: 438/57
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H01L 27/14623 Optical shielding

Abstract

There is provided a solid-state image sensor including a first region in which light is converted into electricity, and a second region composed of silicide. The second region at least partially forms a boarder area of the first region at a surface of the first region. The solid-state image sensor prevents occurrence of smear.

Claims

1. A solid-state image sensor comprising:

a first region in which light is converted into electricity; and

a second region composed of silicide, said second region at least partially forming a boarder area of said first region at a surface of said first region.

2. The solid-state image sensor as set forth in claim 1, wherein said second region interrupts light which would cause smear, from entering said region.

3. The solid-state image sensor as set forth in claim 1, wherein said solid-state image sensor constitutes a CMOS sensor.

4. The solid-state image sensor as set forth in claim 1, wherein said solid-state image sensor constitutes a CCD sensor.

5. The solid-state image sensor as set forth in claim 1, wherein said second region is composed of silicide of refractory metal.

6. A solid-state image sensor comprising:

a first region in which light is converted into electricity;

a reset gate electrode;

a reset drain region; and

a second region composed of silicide, said second region at least partially forming a boarder area of said first region at a surface of said first region.

7. The solid-state image sensor as set forth in claim 6, wherein said second region interrupts light which would cause smear, from entering said region.

8. The solid-state image sensor as set forth in claim 6, wherein said second region is composed of silicide of refractory metal.

9. A solid-state image sensor comprising:

a first region in which light is converted into electricity;

a reset gate electrode;

a reset drain region;

a second region composed of silicide, said second region at least partially forming a boarder area of said first region at a surface of said first region; and

a third region composed of silicide, said third region covering a surface of said reset drain region therewith.

10. The solid-state image sensor as set forth in claim 9, wherein said second and third regions are made of a common layer.

11. The solid-state image sensor as set forth in claim 9, wherein said second region interrupts light which would cause smear, from entering said region.

12. The solid-state image sensor as set forth in claim 9, wherein said second region is composed of suicide of refractory metal.

13. A solid-state image sensor comprising:

a first region in which light is converted into electricity;

a light-impermeable film having an opening situated above said first region; and

a second region composed of silicide, said second region at least partially forming a boarder area of said first region at a surface of said first region such that said second region interrupts diffracted light coming through said opening, from entering said first region.

14. The solid-state image sensor as set forth in claim 13, wherein said second region is composed of silicide of refractory metal.

15. A solid-state image sensor comprising:

a first region in which light is converted into electricity;

a light-impermeable film having an opening situated above said first region;

a reset gate electrode;

a reset drain region; and

a second region composed of silicide, said second region at least partially forming a boarder area of said first region at a surface of said first region such that said second region interrupts diffracted light coming through said opening, from entering said first region.

16. The solid-state image sensor as set forth in claim 15, wherein said second region is composed of silicide of refractory metal.

17. A solid-state image sensor comprising:

a first region in which light is converted into electricity;

a light-impermeable film having an opening situated above said first region;

a reset gate electrode;

a reset drain region;

a second region composed of silicide, said second region at least partially forming a boarder area of said first region at a surface of said first region such that said second region interrupts diffracted light coming through said opening, from entering said first region; and

a third region composed of silicide, said third region covering a surface of said reset drain region therewith.

18. The solid-state image sensor as set forth in claim 17, wherein said second and third regions are made of a common layer.

19. The solid-state image sensor as set forth in claim 17, wherein said second region is composed of silicide of refractory metal.

20. A method of fabricating a solid-state image sensor, comprising the steps of:

(a) forming a first region in which light is converted into electricity, in a silicon substrate, said first region having an electrical conductivity opposite to an electrical conductivity of said silicon substrate; and

(b) forming a second region composed of silicide, said second region forming a boarder area of said first region at a surface of said first region.

21. The method as set forth in claim 20, wherein said step (b) is carried out by silicifying a boarder area of said first region.

22. The method as set forth in claim 20, wherein said step (b) is carried out by depositing a refractory metal film and heating said refractory metal film.

23. The method as set forth in claim 20, further comprising the step of forming a light-impermeable film having an opening situated above said first region.

24. A method of fabricating a solid-state image sensor, comprising the steps of:

(a) forming a first region in which light is converted into electricity, in a silicon substrate, said first region having an electrical conductivity opposite to an electrical conductivity of said silicon substrate;

(b) forming a reset gate on said silicon substrate;

(c) forming a reset drain region in said silicon substrate, said reset drain region having an electrical conductivity opposite to an electrical conductivity of said silicon substrate; and

(d) forming a second region composed of silicide, said second region forming a boarder area of said first region at a surface of said first region.

25. The method as set forth in claim 24, wherein said step (d) is carried out by silicifying a boarder area of said first region.

26. The method as set forth in claim 24, wherein said step (d) is carried out by depositing a refractory metal film and heating said refractory metal film.

27. The method as set forth in claim 24, further comprising the step of forming a light-impermeable film having an opening situated above said first region.

28. The method as set forth in claim 24, further comprising the step of forming a third region on a surface of said reset drain region, said third region being composed of silicide.

29. The method as set forth in claim 28, wherein said second and third regions are simultaneously formed.

30. A method of fabricating a solid-state image sensor, comprising the steps of:

(a) forming a well in a silicon substrate;

(b) forming a first region in which light is converted into electricity, in said well, said first region having an electrical conductivity opposite to an electrical conductivity of said well;

(c) forming a reset gate on said well;

(d) forming a reset drain region in said well, said reset drain region having an electrical conductivity opposite to an electrical conductivity of said well; and

(e) forming a second region composed of silicide, said second region forming a boarder area of said first region at a surface of said first region.

31. The method as set forth in claim 30, wherein said step (e) is carried out by silicifying a boarder area of said first region.

32. The method as set forth in claim 30, wherein said step (e) is carried out by depositing a refractory metal film and heating said refractory metal film.

33. The method as set forth in claim 30, further comprising the step of forming a light-impermeable film having an opening situated above said first region.

34. The method as set forth in claim 30, further comprising the step of forming a third region on a surface of said reset drain region, said third region being composed of silicide.

35. The method as set forth in claim 30, where in said second and third regions are simultaneously formed.