METHOD OF PRODUCING SILICON p-i-n PHOTODIODE Russian patent published in 2015 - IPC H01L31/18 

FIELD: physics.

SUBSTANCE: invention relates to production of silicon p-i-n photodiodes which are sensitive to radiation with wavelength of 0.9-1.06 mcm. Said silicon p-i-n photodiodes are intended for use in different optoelectronic devices which require detection of short laser pulses (10-40 ns). After performing high-temperature thermodiffusion processes to form the photodiode structure: - thermal oxidation; - phosphorus diffusion to form n+-type regions (photosensitive areas and collar rings); - phosphorus diffusion into the back surface of the wafer to generate impurities; - boron diffusion into the back surface of the water after etching a gettering n+-type layer to form a p+-type layer, after forming ohmic contacts, the method includes etching the dielectric film from the silicon surface and etching silicon by a depth less than 1 mcm, followed by depositing a silicon dioxide film using a low-temperature technique at temperature not higher than 800°C. Ohmic contacts are then formed using known techniques.

EFFECT: reduced dark current of photosensitive areas and the collar ring, reduced values of coupling factors between the photosensitive areas of multielement photodiodes and high output of non-defective devices.