Image sensor with reduced p-well conductivity

• US 20050151056A1
• Filed: 01/09/2004
• Published: 07/14/2005
• Est. Priority Date: 01/09/2004
• Status: Active Grant

• Current Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Original Assignee: Eastman Kodak Company
• Inventors: Parks, Christopher
• Granted Patent: US 7,075,129 B2
• Time in Patent Office: Days
• US Class Current: 250/208.100
• CPC Class Codes: H01L 27/14806 Structural or functional details thereof
• CPC Class Codes: H01L 27/14831 Area CCD imagers

Abstract

An image sensor includes a substrate of the first conductivity type; a channel of the first conductivity type that spans at least a portion of the substrate; a well of the second conductivity type that is positioned between the channel and substrate for a predetermined portion and that is not between the substrate and the channel for a predetermined portion all of which well is substantially continuous; and a connection to the well; wherein a resistance of the well not between the substrate and the channel is substantially equal to or greater than twenty five percent of a total resistance of the well between the channel and the substrate.

Claims

1. An image sensor comprising:

(a) a substrate of the first conductivity type;

(b) a channel of the first conductivity type that spans at least a portion of the substrate;

(c) a well of the second conductivity type that is positioned between the channel and substrate for a predetermined portion and that is not between the substrate and the channel for a predetermined portion all of which well is substantially continuous; and

(d) a connection to the well;

wherein a resistance of the well not between the substrate and the channel is substantially equal to or greater than twenty five percent of a total resistance of the well between the channel and the substrate.

2. The image sensor as in claim 1, wherein the channel is a buried channel.

3. A camera comprising:

an image sensor comprising;

(a) a substrate of the first conductivity type;

(b) a channel of the first conductivity type that substantially spans the substrate;

(c) a well of the second conductivity type that is positioned between the channel and substrate for a predetermined portion and that is not between the substrate and the channel for a predetermined portion all of which well is substantially continuous; and

(d) a connection to the well;

wherein a resistance of the well not between the substrate and the channel is substantially equal to or greater than twenty five percent of a total resistance of the well between the channel and the substrate.

4. The camera as in claim 3, wherein the channel is a buried channel.