Complementary metal-oxide-semiconductor image sensor sturcture of mixed integration area and potential reading method employing the same

摘要

The present invention provides a complementary metal-oxide-semiconductor (CMOS) image sensor structure and the potential reading method employing the same. The integration area composed of the photo diode and the photo gate is applied to receive the light emitted from the light source. The sensitivity is changed via the operation of controlling the gate voltage of the photo gate. Moreover, the variance of the potential is read many times. The characteristic of the potentials under different conditions in different times having the same dark current and fixed pattern noise is utilized. The dark current and the fixed pattern noise can be eliminated by calculating their difference. Higher sensitivity in low illumination and lower sensitivity in high illumination can be obtained by calculating their summation, so as to increase the dynamic range.