Unit pixel in CMOS image sensor with enhanced reset efficiency

A unit pixel for use in the CMOS image sensor comprising:

• a semiconductor substrate including an epitaxial layer in which an active area and a field oxide (FOX) area are defined;
• a photodiode formed in a predetermined location of the epitaxial layer;
• a transfer transistor including source/drain regions disposed between the photodiode and a floating diffusion node, wherein a transfer control signal is applied to a gate thereof;
• a reset transistor including source/drain regions disposed between the photodiode and a power supply voltage (VDD) terminal, wherein a reset control signal is applied to a drain thereof;
• a drive transistor of which a gate electrode is connected to the floating diffusion region and a drain is connected to the VDD terminal;
• and
• a selection transistor of which a drain is connected to the drain of the drive transistor and a source is connected to an output terminal, wherein a select control signal is applied to a gate thereof.

A CMOS image sensor having a plurality of unit pixels, said each unit pixel comprising:

• a semiconductor substrate including an epitaxial layer in which an active area and a field oxide (FOX) area are defined;
• a photodiode formed in a predetermined location of the epitaxial layer;
• a transfer transistor including source/drain regions disposed between the photodiode and a floating diffusion region, wherein a transfer control signal is applied to a gate thereof;
• a reset transistor including source/drain regions disposed between the floating diffusion region and a power supply voltage (VDD) terminal, wherein a reset control signal is applied to a drain thereof;
• a drive transistor of which a gate is connected to the floating diffusion region and a drain is connected to the VDD terminal;
• and
• a selection transistor of which a drain is connected to a source of the drive transistor and a source is connected to an output terminal, wherein a select control signal is applied to a gate thereof.

A CMOS image sensor having a plurality of unit pixels, said each unit pixel comprising:

• a semiconductor substrate including an epitaxial layer in which an active area and a field oxide (FOX) area are defined;
• a photodiode formed in a predetermined location of the epitaxial layer;
• a transfer transistor including source/drain regions disposed between the photodiode and a floating diffusion node, wherein a transfer control signal is applied to a gate thereof;
• a reset transistor including source/drain regions disposed between the photodiode and a power supply voltage (VDD) terminal, wherein a reset control signal is applied to a drain thereof;
• a drive transistor of which a gate electrode is connected to the floating diffusion region and a drain is connected to the VDD terminal;
• and
• a selection transistor of which a drain is connected to the drain of the drive transistor and a source is connected to an output terminal, wherein a select control signal is applied to a gate thereof.