Method and apparatus for controlling charge transfer in CMOS sensors with an implant by the transfer gate

Abstract

An improved CMOS sensor integrated circuit is disclosed, along with methods of making the circuit and computer readable description' s of the circuit.

1 . An image sensor integrated circuit, comprising:
 a plurality of photodetectors generating charge carriers excited by incident photons, each of the plurality of photodetectors including:
 an first charge type region receiving the charge carriers excited by the energy of the photons; 
   a plurality of nodes, wherein each of the plurality of photodetectors has a corresponding node of the plurality of nodes;   a plurality of transfer devices controlling a transfer of the charge carriers from said each of the plurality of photodetectors to the corresponding node, the plurality of transfer devices having a transfer device background second charge type concentration under a control terminal, each of the plurality of transfer devices including:
 a first terminal coupled to the first charge type region of one of the plurality of photodetectors; 
 a second terminal coupled to one of the plurality of nodes; and 
 the control terminal receiving a control signal, wherein the transfer of the charge carriers occurs between the first terminal and the second terminal in response to the control signal of sufficient value applied to the control terminal; 
   a first plurality of second charge type regions having a concentration stronger than the transfer device background second charge type concentration, wherein each of the first plurality of second charge type regions has a lateral position only partly under the control terminal of a transfer device of the plurality of transfer devices, the first plurality of second charge type regions controlling the transfer of charge carriers from a photodetector of the plurality of photodetectors to the corresponding node of the photodetector, and each of the first plurality of second charge type regions has the lateral position at least partly under the corresponding node, and the first plurality of second charge type regions has the lateral position stopping short of the plurality of photodetectors and stopping short of a plurality of reset devices;   the plurality of reset devices, wherein each of the plurality of nodes has a corresponding reset device of the plurality of reset devices, and said each of the plurality of nodes is reset when the corresponding reset device is active;   row and column circuitry; and   a plurality of signal devices coupling the plurality of nodes to the row and column circuitry.