Features of Diffusion Doping and Boron Gettering of Silicon p-i-n Photodiodes

Boron diffusion was studied in the manufacture of four-element silicon p-i-n photodiodes with a guard ring using planar technology. Substrate gettering by means of boron diffusion in the opposite direction of plates from planar sources has been studied. The dependence of the surface resistance and the depth of the P ^+- p-junction on the duration of the diffusion process has been established. Optimal diffusion regimes have been determined to obtain the minimum dark currents and maximum responsivity due to the gettering of generation-recombination centers and the restoration of the time of minor charge carriers. The transmission spectra of wafers with different surface resistances and p ⁺ -p-junction depths have been studied to ensure the maximum efficiency of reflection of the gold layer from the rear side of the substrate. Surface defect formation during boron diffusion has been studied.