Active pixel sensor integrated with a pinned photodiode
First Claim
Patent Images
1. A method of forming an active pixel sensor comprising the steps of:
- providing a semiconductor substrate of a first conductivity type with an array of pixels on it; and
providing at least one pixel with a pinned photodiode having a pinning layer heavily doped of the first conductivity type and a photodiode heavily doped of a second conductivity type and at a depth deeper than source and drain regions of CMOS within the array of pixels that is operatively coupled to a sensing node conpised of a floating diffusion connected to a CMOS control circuitry through a transfer gate controlled by said CMOS control circuitry, the at least one pixel further comprising means for transferring charge from the pinned photodiode to a floating diffusion area under control of a transfer gate for charge to voltage conversion within the pixel such that the pinned photodiode, the transfer gate and a charge sensing means acts as, respectively, the source, the gate and the drain of a MOSFET.
1 Assignment
0 Petitions
Accused Products
Abstract
The optimization of two technologies (CMOS and CCD) wherein a pinned photodiode is integrated into the image sensing element of an active pixel sensor. Pinned photodiodes are fabricated with CCD process steps into the active pixel architecture. Charge integrated within the active pixel pinned photodiode is transferred into the charge sensing node by a transfer gate. The floating diffusion is coupled CMOS circuitry that can provide the addressing capabilities of individual pixels. Alternatively, a buried channel photocapacitor can be used in place of the pinned photodiode.
73 Citations
2 Claims
-
1. A method of forming an active pixel sensor comprising the steps of:
-
providing a semiconductor substrate of a first conductivity type with an array of pixels on it; and
providing at least one pixel with a pinned photodiode having a pinning layer heavily doped of the first conductivity type and a photodiode heavily doped of a second conductivity type and at a depth deeper than source and drain regions of CMOS within the array of pixels that is operatively coupled to a sensing node conpised of a floating diffusion connected to a CMOS control circuitry through a transfer gate controlled by said CMOS control circuitry, the at least one pixel further comprising means for transferring charge from the pinned photodiode to a floating diffusion area under control of a transfer gate for charge to voltage conversion within the pixel such that the pinned photodiode, the transfer gate and a charge sensing means acts as, respectively, the source, the gate and the drain of a MOSFET. - View Dependent Claims (2)
-
Specification
-
- Resources
Litigation Campaign Assessment
Thank you for your request. You will receive a custom alert email when the Litigation Campaign Assessment is available.
×
-
Current AssigneeOmnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
-
Original AssigneeEastman Kodak Company
-
InventorsStevens, Eric Gordon, Guidash, Robert M., Lee, Paul P., Lee, Teh-Hsuang
-
Primary Examiner(s)Mulpuri, Savitri
-
Application NumberUS09/436,371Time in Patent Office694 DaysField of Search438/57, 438/73, 438/78, 438/59, 438/60, 438/210, 438/237, 438/91, 438/200, 438/514, 438/527, 257/291, 257/292, 257/290, 257/232, 257/233, 257/369US Class Current438/57CPC Class CodesH01L 27/14609 Pixel-elements with integra...H01L 27/14643 Photodiode arrays; MOS imagers
