HIGH SIGNAL-TO-NOISE RATIO INFRARED PHOTODIODE AND METHOD OF INCREASING SIGNAL-TO-NOISE RATIO IN INFRARED PHOTODIODE Russian patent published in 2012 - IPC H01L31/101 

FIELD: physics.

SUBSTANCE: high signal-to-noise (S/N) ratio infrared photodiode has a heavily doped layer (1) of a main p-n junction, a heavily doped layer (2) of an additional p-n junction, a padded base (3) for the main and additional p-n junctions and a substrate (5). The common base (3) has a space-charge region (4) for the main p-n junction. An ohmic contact (6, 7, 8) is formed for each of the layers of the structure. The total thickness of the heavily doped layer of the main p-n junction and the space-charge region of the main p-n junction lying in the common base satisfies a condition defined by a mathematical expression. To increase the S/N ratio in the infrared photodiode, diffusion current of the additional p-n junction and the sum of the diffusion current and photocurrent of the main p-n junction are recorded, and the diffusion current of the additional p-n junction is then used for correlation processing of the signal and noise of the main p-n junction. S/N ratio in the infrared photodiode is increased by using diffusion current of the additional p-n junction, whose noise is correlated with noise of the diffusion current of the main (infrared radiation detecting) p-n junction, for correlation processing of the signal and noise of the main p-n junction.

EFFECT: high signal-to-noise ratio of the infrared photodiode.

2 cl, 2 dwg