Image sensor and method for manufacturing the same
AssigneeSamsung Electronics Co., Ltd.
InventorsJae-Ryung Yoo, Keun-Chan Yuk
Life of this patent
Estimating the term…
Abstract
An image sensor may include a photo diode, a transfer transistor configured to transfer a photo charge generated by the photo diode to a floating diffusion region and buried channel transistors electrically coupled to the transfer transistor, wherein each of the transistors have a buried channel. The noise of the image sensor may be reduced because a channel of the buried-channel transistors in the active pixel region may be formed apart from a defected surface of a substrate when the buried-channel transistors are turned on.
Claims19
1-14. (canceled)
A method for manufacturing an image sensor, comprising:
- forming a photo diode by doping an impurity into a portion of a substrate;
- forming a gate insulator on the substrate;
- forming a polysilicon layer on the gate insulator;
- doping a P-type impurity into a portion of the polysilicon layer;
- forming a first hard mask pattern on the polysilicon layer;
- forming gate electrodes of a transfer transistor and buried-channel transistors by etching the polysilicon layer doped with a P-type impurity using the first hard mask pattern as an etching mask, each of the buried-channel transistors having a buried channel;
- and
- forming a first source/drain by doping an N-type impurity into the substrate away from both sides of the gate electrodes of the buried-channel transistors using the first hard mask pattern as an ion implantation mask.
A method for manufacturing an image sensor, comprising:
- forming a photo diode by doping an impurity into a portion of an active pixel region of a substrate;
- forming a gate insulator on the substrate;
- forming a polysilicon layer on the gate insulator;
- ion-implanting a P-type impurity into a portion of the polysilicon layer on which a transistor is formed in the active pixel region and into a portion of the polysilicon layer on which a positive channel metal oxide semiconductor (PMOS) transistor is formed in a peripheral circuit region;
- ion-implanting an N-type impurity into a portion of the polysilicon layer on which a negative channel metal oxide semiconductor (NMOS) transistor is formed in the peripheral circuit region;
- forming gate electrodes of a transfer transistor and buried-channel transistors in the active pixel region and gate electrodes of the NMOS transistor and the PMOS transistor in the peripheral circuit region by patterning the polysilicon layer, each of the buried-channel transistors having a buried channel;
- forming a first source/drain and a second source/drain by selectively doping an N-type impurity into the substrate away from both sides of the gate electrodes of the buried-channel transistors and into the substrate away from both sides of the gate electrode of the NMOS transistor respectively;
- and
- forming a third source/drain by doping selectively a P-type impurity into the substrate away from both sides of the gate electrode of the PMOS transistor.
Dependencies are inferred from the claim text.