METHOD OF PRODUCING A MULTI-SITE SILICON PIN-PHOTOSENSITIVE ELEMENT WITH LOW DARK CURRENT LEVEL Russian patent published in 2020 - IPC H01L31/18 

FIELD: manufacturing technology; physics.

SUBSTANCE: invention relates to the production of silicon pin-photosensitive elements sensitive to radiation with wavelength of 1.06 mcm. They are intended for use in various electronic-optical equipment, in which registration of short laser radiation pulses (10–40 ns) is required at offset voltages of order of 200 V. Method of making a multi-site silicon pin-photosensitive element involves ionic boron implantation and distillation into the back surface of the substrate, thermal oxidation, diffusion and phosphorus distillation to create areas of photosensitive sites and a guard ring with simultaneous oxidation of the formation of a protective film of silicon dioxide, ionic implantation of argon and diffusion of phosphorus into the back surface of the substrate for gettering, removal of gettering layer, diffusion of boron into back surface of substrate for creation of contact layer p⁺-type of conductivity, chemical etching of silicon dioxide film to obtain antireflection coating, creation of two-layer gold ohmic contacts to photosensitive sites, a guard ring and back layer ⁺-type of conductivity, wherein according to the invention, two-step gettering is carried out to remove contaminants, including a phosphorus padding in the rear side of the plate at temperature of 1,100 °C for 20 minutes and subsequent annealing for 1 hour, removal of phosphosilicate glass from the back side of the plate, ion implantation of argon in rear side of plate with dose of 2⋅10¹⁵ cm^-2 and energy 100 keV, thermal annealing at temperature 1,000 °C for 1 hour.

EFFECT: invention provides reduced level of dark currents.

1 cl, 1 dwg, 1 tbl, 1 ex