CMOS compatible single phase CCD charge transfer device

• US 6,465,820 B1
• Filed: 09/10/1999
• Issued: 10/15/2002
• Est. Priority Date: 09/16/1998
• Status: Expired due to Term

• Current Assignee: Teledyne Digital Imaging, Inc. (Teledyne Technologies Incorporated)
• Original Assignee: Dalsa Incorporated (Teledyne Technologies Incorporated)
• Inventors: Fox, Eric
• Primary Examiner(s): Tran, Minh Loan
• Assistant Examiner(s): Dickey, Thomas L
• Application Number:
  US09/393,312
• Time in Patent Office: 1,131 Days
• Field of Search: 257/215-16, 257/222-23, 257/218-19, 257/221, 257/225, 257/231-33, 257/288, 257/290.93, 377/58, 377/60
• US Class Current: 257/223
• CPC Class Codes: H01L 27/14806 Structural or functional details thereof
• CPC Class Codes: H01L 27/14856 Time-delay and integration

Abstract

A single phase charge-couple device (CCD) transfer device in a substrate of a first conductivity type. The device includes a gated region and a photo-diode region. The gated region includes a gated part and a gate electrode insulatively spaced over the gated part. The photo-diode region includes first, second, and third diode sub-regions. The second diode sub-region is formed of a second conductivity type; the third diode sub-region is formed of the first conductivity type in the second diode sub-region; and the first diode sub-region is formed of the first conductivity type in the second diode sub-region. The first and third diode sub-regions contain different dopant concentrations. The gated part is either a buried channel gated part or a surface channel gated part. The buried channel gated part includes a channel of the second conductivity type and a first gated sub-region formed in the channel.

Claims

1. A device formed in a substrate of a first conductivity type, the device comprising:

a gated region that includes a gated part and a gate electrode insulatively spaced over the gated part; and

a photo-diode region having proximal and distal sides, the proximal side being adjacent to the gated region, the photo-diode region including first, second and third diode sub-regions, the second diode sub-region being formed of a second conductivity type in the substrate, the third diode sub-region being formed of the first conductivity type in the second diode sub-region in the proximal side, the first diode sub-region being formed of the first conductivity type in the second diode sub-region in the distal side, a first dopant species constituting a highest concentration of any dopant species in both the first and third diode sub-regions, wherein the first and third diode sub-regions contain different dopant concentrations of the first dopant species.

2. A device formed in a substrate of a first conductivity type, the device comprising:

a gated region that includes a gated part and a gate electrode insulatively spaced over the gated part; and

a photo-diode region having proximal and distal sides, the proximal side being adjacent to the gated region, the photo-diode region including first, second and third diode sub-regions, the second diode sub-region being formed of a second conductivity type in the substrate, the third diode sub-region being formed of the first conductivity type in the second diode sub-region in the proximal side, the first diode sub-region being formed of the first conductivity type in the second diode sub-region in the distal side, wherein the first and third diode sub-regions contain different dopant concentrations of a same species so as to generate an internal field that induces charge carriers to drift to the proximal side.

3. A device formed in a substrate of a first conductivity type, the device comprising:

a gated region that includes a gated part and a gate electrode insulatively spaced over the gated part, the gated part including a channel of a second conductivity type formed in the substrate and a first gated sub-region formed in the channel so as to define a second gated sub-region as a remaining portion of the channel; and

a photo-diode region having proximal and distal sides, the proximal side being adjacent to the first gated sub-region, the photo-diode region including first, second and third diode sub-regions, the second diode sub-region being formed of the second conductivity type in the substrate, the third diode sub-region being formed of the first conductivity type in the second diode sub-region in the proximal side, the first diode sub-region being formed of the first conductivity type in the second diode sub-region in the distal side, and wherein the first gated sub-region provides a lesser density of majority carriers than is provided by the second gated sub-region.

4. The device of claim 3, wherein:

the second gated sub-region includes a dopant species of a first polarity type; and

the first gated sub-region is of the second conductivity type and includes the dopant species of the first polarity type and a dopant species of a second polarity type, the second polarity type being opposite to the first polarity type.

5. The device of claim 3, wherein:

the channel includes a dopant species of a first polarity type; and

the first gated sub-region includes a dopant species of a second polarity type, the second polarity type being an opposite polarity to the first polarity type.

6. The device of claim 3, wherein:

a first dopant species constitutes a highest concentration of any dopant species in both the first and third diode sub-regions; and

the first and third diode sub-regions contain different dopant concentrations of the first dopant species.

7. A device formed in a substrate of a first conductivity type, the device comprising:

a gated region that includes a gated part and a gate electrode insulatively spaced over the gated part; and

a photo-diode region having proximal and distal sides, the proximal side being adjacent to the gated region, the photo-diode region including first, second and third diode sub-regions, the second diode sub-region being formed of a second conductivity type in the substrate, the third diode sub-region being formed of the first conductivity type in the second diode sub-region in the proximal side, the first diode sub-region being formed of the first conductivity type in the second diode sub-region in the distal side, wherein the second diode sub-region is self-aligned with the gate electrode and a gate electrode of an adjacent device abutting the distal side, and wherein the first diode sub-region is self aligned with the gate electrode of the adjacent device abutting the distal side.

8. A device formed in a substrate of a first conductivity type, the device comprising:

a gated region that includes a gated part and a gate electrode insulatively spaced over the gated part, the gated part including a first gated sub-region formed in the substrate and a remaining portion of the gated part that is constituted by a sub-portion of the substrate; and

a photo-diode region having proximal and distal sides, the proximal side being adjacent to the gated region, the photo-diode region including first, second and third diode sub-regions, the second diode sub-region being formed of a second conductivity type in the substrate, the third diode sub-region being formed of the first conductivity type in the second diode sub-region in the proximal side, the first diode sub-region being formed of the first conductivity type in the second diode sub-region in the distal side.

9. The device of claim 8 wherein:

the remaining portion includes a dopant species of a first polarity type in a concentration to define a first majority carrier density; and

the first gated sub-region includes the dopant species of the first polarity type in a concentration to define a second majority carrier density, the second majority carrier density being greater than the first majority carrier density.

10. The device of claim 8, wherein the first gated sub-region is formed in the substrate so as to provide a stair step potential profile in the gated region.

11. The device of claim 8, wherein the first gated sub-region is formed to be of the first conductivity type.

12. The device of claim 8, wherein:

the remaining portion includes a dopant species of a first polarity type in a concentration to define a first majority carrier density; and

the first gated sub-region includes the dopant species of the first polarity type in a concentration to define a second majority carrier density, the second majority carrier density being greater than the first majority carrier density.

13. The device of claim 12, wherein the first and third diode sub-regions contain different dopant concentrations of a same species.

14. The device of claim 8, wherein the first gated sub-region is formed in the substrate so as to provide a stair step potential profile in the gated region.

15. A device formed in a substrate of a first conductivity type, the device comprising:

a gated region that includes a gated part and a gate electrode insulatively spaced over the gated part, the gated part including a first gated sub-region formed in the substrate and a remaining portion of the gated part, the remaining portion being a sub-portion of the substrate; and

a photo-diode region having proximal and distal sides, the proximal side being adjacent to the gated region, the photo-diode region including first, second and third diode sub-regions, the second diode sub-region being formed of a second conductivity type in the substrate, the third diode sub-region being formed of the first conductivity type in the second diode sub-region in the proximal side, the first diode sub-region being formed of the first conductivity type in the second diode sub-region in the distal side, wherein the second diode sub-region is self-aligned with the gate electrode and a gate electrode of an adjacent device abutting the distal side, and wherein the first diode sub-region is self aligned with the gate electrode of the adjacent device abutting the distal side.

16. A device formed in a substrate of a first conductivity type, the device comprising:

a gated region that includes a gated part and a gate electrode insulatively spaced over the gated part, the gated part including a channel of a second conductivity type formed in the substrate and a first gated sub-region formed in the channel so as to define a second gated sub-region as a remaining portion of the channel, the second gated sub-region having a greater density of majority carriers than the first gated sub-region; and

a photo-diode region having proximal and distal sides, the proximal side being adjacent to the region, the photo-diode region including first, second and third diode sub-regions, the second diode sub-region being formed of the first conductivity type in the second diode sub-region in the proximal side, the first diode sub-region being formed of the first conductivity type in the second diode sub-region in the distal side.

17. A device formed in a substrate of a first conductivity type, the device comprising:

a gated region that includes a gated part and a gate electrode insulatively spaced over the gated part, the gated part including a channel of a second conductivity type formed in the substrate and a first gated sub-region of the second conductivity type formed in the channel so as to define a second gated sub-region as a remaining portion of the channel, the first and second gated sub-regions including a dopant species of a first polarity type, the dopant species of the first polarity type constituting a highest concentration of any dopant species in both the first and second gated sub-regions, the first gated sub-region including a dopant species of a second polarity type, the second polarity type being opposite to the first polarity type; and

photo-diode region having proximal and distal sides, the proximal side being adjacent to the gated region, the photo-diode region including first, second and third diode sub-regions, the second diode sub-region being formed of the second conductivity type in the substrate, the third diode sub-region-being formed of the first conductivity type in the second diode sub-region in the proximal side, the first diode sub-region being formed of the first conductivity type in the second diode sub-region in the distal side.

18. The device of claim 17, wherein the first gated sub-region further includes the dopant species of the first polarity type.

19. The device of claim 17, wherein:

the third diode sub-region includes the dopant species of the second polarity type;

the first diode sub-region includes one of the dopant species of the second polarity type and another dopant species of the second polarity type; and

the first and third diode sub-regions contain different dopant concentrations of the second polarity type.

20. The device of claim 17, wherein the dopant species of the second polarity type is absent from the second gated sub-region.

21. A device formed in a substrate of a first conductivity type, the device comprising:

a gated region that includes a gated part and a gate electrode insulatively spaced over the gated part; and

a photo-diode region having proximal and distal sides, the proximal side being adjacent to the gated region, the photo-diode region including first, second and third diode sub-regions, the second diode sub-region being formed of a second conductivity type of substantially uniform concentration in the substrate, the third diode sub-region being formed of the first conductivity type in the second diode sub-region in the proximal side, the first diode sub-region being formed of the first conductivity type in the second diode sub-region in the distal side.

22. A device formed in a substrate of a first conductivity type, the device comprising:

a gated region that includes a gated part and a gate electrode insulatively spaced over the gated part; and

a photo-diode region having proximal and distal sides, the proximal side being adjacent to the gated region, the photo-diode region including first, second and third diode sub-regions, the second diode sub-region being formed of a second conductivity type in the substrate and being self-aligned with the gate, electrode and a gate electrode of an adjacent device abutting the distal side, the third diode sub-region being formed of the first conductivity type in the second diode sub-region in the proximal side, the first diode sub-region being formed of the first conductivity type in the second diode sub-region in the distal side and being self aligned with the gate electrode of the adjacent device abutting the distal side.