METHOD OF THE DRIP ETCHING OF THE CONTACT PLATFORM OF THE BUILT-IN DIODE OF A PHOTO CONVERTER Russian patent published in 2019 - IPC H01L31/18 

FIELD: power engineering.

SUBSTANCE: invention relates to solar power engineering, in particular, to methods for manufacturing photovoltaic cells on three-stage GaInP/Ga (In) As/Ge epitaxial structures grown on a germanium substrate. Method of drip etching of the contact pad of the built-in photo converter diode includes creating a masking photoresist with windows of the photo converter front contacts and a diode on a three-stage GaInP/Ga (In) As/Ge semiconductor structure with p⁺⁺ and n⁺⁺ layers of the tunnel junction of the upper cascade, droplet etching in the diode window of the mask of semiconductor layers of the upper cascade to n⁺⁺ the tunnel junction layer in hydrochloric acid based etchants, in the process of etching after the occurrence of gas bubbles around the perimeter of the diode window in the mask, they are removed hydrodynamically by remotely applying drops of the etchant in the region of the diode window, and after washing and drying, the contact area of the diode in the etchant composition is treated: concentrated hydrochloric acid in a proportion of from 30 to 70 % of the total volume, the rest being is an aqueous solution of potassium dichromate of 5–45 % concentration.

EFFECT: technical result achieved in the proposed method of etching the contact pad of the built-in photo converter diode, is to increase the adhesion of the face metallization of the diode and reduce the magnitude of the forward voltage on the built-in diode.

1 cl, 2 dwg, 1 tbl