Optical Sensor Including Stacked Photosensitive Diodes

摘要

A complementary metal-oxide-semiconductor (CMOS) image sensor comprises a first photosensitive diode comprising a first semiconductor material is formed in a first semiconductor substrate. A second photosensitive diode comprising a second semiconductor material, which has a different light detection wavelength range than the first semiconductor material, is formed in a second semiconductor substrate. Semiconductor devices for holding and detecting charges comprising a sensing circuit of the CMOS image sensor may also be formed in the second semiconductor substrate. The first semiconductor substrate and the second semiconductor substrate are bonded so that the first photosensitive diode is located underneath the second photosensitive diode. The vertical stack of the first and second photosensitive diodes detects light in the combined detection wavelength range of the first and second semiconductor materials. Sensing devices may be shared between the first and second photosensitive diodes.