METHOD OF MANUFACTURING A MULTI-FILM SILICON PIN-PHOTOSENSITIVE ELEMENT Russian patent published in 2018 - IPC H01L31/18 

FIELD: microelectronics.

SUBSTANCE: invention relates to a technique for manufacturing silicon pin-photosensitive elements (PSE) sensitive to radiation with a wavelength of 1.06 μm, intended for use in various electronic optical equipment, in which it is required to register short pulses of laser radiation. method of manufacturing a multi-site photosensitive element on silicon substrates with a resistivity of more than 20 kOhm⋅cm includes operations of thermal oxidation, diffusion of phosphorus to form regions n⁺-type of conductivity, distillation of phosphorus with simultaneous oxidation to grow a protective film of silicon dioxide, diffusion of phosphorus into the back surface of the substrate for gettering of contaminants, removal of the getter layer, diffusion of boron into the back surface of the substrate to form a contact layer p⁺-type of conductivity, chemical etching operation of the silica film to produce an antireflection coating and the operation of creating two-layer ohmic contacts to the photosensitive sites, the guard ring and the back layer p⁺type conductivity by the method of deposition of a gold film with a sublayer of chromium, thickness of the chromium film on the back layer is 5-6 nm.

EFFECT: according to the invention, ionic implantation of boron into the back surface of the substrate and its prolonged distillation are carried out to create a thick contact layer p to increase the speed and monochromatic impulse sensitivity at a wavelength of 1 06/100 μm and increase the percentage of output suitable for the initial stage of fabrication of the PSE_⁺-type of conductivity.

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