Alternate method for photodiode formation in CMOS image sensors

• US 6,504,195 B2
• Filed: 12/29/2000
• Issued: 01/07/2003
• Est. Priority Date: 12/29/2000
• Status: Expired due to Term

• Current Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Original Assignee: Eastman Kodak Company
• Inventors: Guidash, Robert M.
• Primary Examiner(s): Wilson, Allan R.
• Application Number:
  US09/750,941
• Publication Number:
  US 20020121656A1
• Time in Patent Office: 739 Days
• Field of Search: 257/187, 257/292, 257/458
• US Class Current: 257/292
• CPC Class Codes: H01L 21/823425 manufacturing common source or drain regions between a plurality of conductor-insulator-semiconductor structures
• CPC Class Codes: H01L 21/823443 silicided or salicided gate conductors
• 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 27/14689 MOS based technologies

Abstract

A complementary metal oxide semiconductor (CMOS) active pixel sensor (APS) having a plurality of pixels which includes at least one pixel entailing a photodetector, a transistor adjacent the photodetector having a silicide surface, and an insulator over the photodetector. The insulator has a thickness sufficient to prevent the silicide surface from forming over the photodetector and contains an insulator as a field oxide.

Claims

1. A complementary metal oxide semiconductor (CMOS) active pixel sensor (APS) comprising a plurality of pixels;

at least one of said pixels comprising;

a photodetector;

a transistor adjacent said photodetector, said transistor including a silicide surface; and

an insulator over said photodetector, wherein said insulator has a thickness sufficient to prevent said silicide surface from forming over said photodetector.

2. The CMOS APS in claim 1, wherein said insulator comprises a field oxide.

3. The CMOS APS in claim 1, wherein said photodetector comprises a pinned photodiode and said CMOS APS further comprises a pinning layer between said photodetector and said insulator.

4. The CMOS APS in claim 1, further comprising a silicon substrate, wherein said photodetector comprises a doped region in said silicon substrate.

5. The CMOS APS in claim 1, wherein said transistor comprises a reset transistor having a silicided source region adjacent said photodetector, a silicided gate adjacent said source region and a silicided drain region on an opposite side of said gate from said source.

6. The CMOS APS in claim 1, wherein said transistor comprises a row select transistor having a silicided gate adjacent said photodetector and a silicided drain region on an opposite side of said gate from said photodetector.

7. A complementary metal oxide semiconductor (CMOS) pixel sensor comprising a plurality of pixels;

at least one of said pixels comprising;

a photodetector;

a transistor adjacent said photodetector, said transistor including a silicide surface; and

an insulator over said photodetector, wherein said insulator has a thickness sufficient to prevent said silicide surface from forming over said photodetector.

8. The CMOS pixel sensor in claim 7, wherein said insulator comprises a field oxide.

9. The CMOS pixel sensor in claim 7, wherein said photodetector comprises a pinned photodiode and said CMOS further comprises a pinning layer between said photodetector and said insulator.

10. The CMOS pixel sensor in claim 7, further comprising a silicon substrate, wherein said photodetector comprises a doped region in said silicon substrate.

11. The CMOS pixel sensor in claim 7, wherein said transistor comprises a reset transistor having a silicided source region adjacent said photodetector, a silicided gate adjacent said source region and a silicided drain region on an opposite side of said gate from said source.

12. The CMOS pixel sensor in claim 7, wherein said transistor comprises a row select transistor having a silicided gate adjacent said photodetector and a silicided drain region on an opposite side of said gate from said photodetector.