Hynix Semiconductor Inc.

Hang Kyoo Kim

Seo Kyu Lee

Jung Soon Shin

The present invention relates to a CMOS image sensor and a fabrication method thereof. The sensor has a photo diode region being extended to a lower portion of an active region in which a transfer gate, sensing gate and reset gate are formed and therefrom the sensitivity of the CMOS image sensor is enhanced. The sensor of the present invention includes a unit cell region having a first region and a second region adjacent to the first region, a PDN region having a first PDN region which is extended from the surface in the first region into the bulk in a direction perpendicular to the surface in an accompanying drawing and a second PDN region which is extended from the lower portion of the first PDN region into the lower portion of the second region in a horizontal direction in the accompanying drawing, and a floating diffusion region and a reset region which are formed in a surface of the second region above the second PDN region.

CMOS image sensor and a fabrication method for the same

An active pixel circuit in a CMOS image sensor includes a photodiode to accumulate charge due to incident light. A first transfer transistor is arranged to pass a transfer signal when turned on by a column selection signal. A second transfer transistor transfers the accumulated charge from the photodiode to a first floating node when turned on by the transfer signal from the first transfer transistor. A source follow driver transistor changes the potential of a second floating node according to the charge transferred to the first floating node. A line selecting transistor reads out the potential of the second floating node when turned on by a line selection signal, and a reset transistor resets the charges accumulated in the first floating node when the reading out operation is finished.

Active pixel circuit in CMOS image sensor

A CMOS image sensor and a fabrication method thereof are disclosed. The sensor has a photo diode region being extended to a lower portion of an active region in which a transfer gate, sensing gate and reset gate are formed and therefrom the sensitivity of the CMOS image sensor is enhanced. The sensor of the present invention includes a unit cell region having a first region and a second region adjacent to the first region, a PDN region having a first PDN region which is extended from the surface in the first region into the bulk in a direction perpendicular to the surface in an accompanying drawing and a second PDN region which is extended from the lower portion of the first PDN region into the lower portion of the second region in a horizontal direction in the accompanying drawing, and a floating diffusion region and a reset region which are formed in a surface of the second region above the second PDN region.

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Taegu-kwangyokshi, South Korea

Hang Kyoo Kim