Solid-state image sensor and method of fabricating the same

• US 6,703,256 B2
• Filed: 10/03/2001
• Issued: 03/09/2004
• Est. Priority Date: 08/27/1998
• Status: Expired due to Fees

• Current Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Original Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Inventors: Nakashiba, Yasutaka, Nagata, Tsuyoshi
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): Luu, Chuong A
• Application Number:
  US09/968,880
• Publication Number:
  US 20020009823A1
• Time in Patent Office: 888 Days
• Field of Search: 438/48, 438/69, 438/70, 438/300, 438/309
• US Class Current: 438/48
• 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 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 border area of said first region at a surface of said first region.

2. The method as set forth in claim 1, wherein said step (b) is carried out by silicifying a border area of said first region.

3. The method as set forth in claim 1, wherein said step (b) is carried out by depositing a refractory metal film and heating said refractory metal film.

4. The method as set forth in claim 1, further comprising the step of forming a light-impermeable film having an opening situated above said first region.

5. 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 suicide, said second region forming a border area of said first region at a surface of said first region.

6. A method as set forth in claim 5, wherein said step (d) is carried out by silicifying a border area of said region.

7. The method as set forth in claim 5, wherein said step (d) is carried out by depositing a refractory metal film and heating said refractory metal film.

8. The method as set forth in claim 5, further comprising the step of forming a light-impermeable film having an opening situated above said first region.

9. The method as set forth in claim 5, further comprising the step of forming a third region on a surface of said reset drain region, said third region being composed of silicide.

10. The method as set forth in claim 9, wherein said second and third regions are simultaneously formed.

11. 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 border area of said first region at a surface of said first region.

12. The method as set forth in claim 11, wherein said step (e) is carried out by silicifying a border area of said first region.

13. The method as set forth in claim 11, wherein said step (e) is carried out by depositing a refractory metal film and heating said refractory metal film.

14. The method as set forth in claim 11, further comprising the step of forming a light-impermeable film having an opening situated above said first region.

15. The method as set forth in claim 11, further comprising the step of forming a third region on a surface of said reset drain region, said third region being composed of silicide.

16. The method as set forth in claim 11, where in said second and third regions are simultaneously formed.