METHOD OF FORMING OPTICALLY TRANSPARENT OHMIC CONTACT TO SURFACE OF SEMICONDUCTOR OPTICAL WAVEGUIDE OF ELECTROOPTICAL MODULATOR Russian patent published in 2020 - IPC H01L21/28 

FIELD: microelectronics technologies.

SUBSTANCE: method for forming an optically transparent ohmic contact to the surface of the semiconductor optical waveguide electrooptic modulator made based on heteroepitaxial pin InP/InGaAs structure includes sputtering of contact electrode film on surface p⁺-InGaAs by magnetron sputtering with subsequent deposition on its surface of silicon nitride dielectric layer by plasma-chemical deposition, formation of a dielectric mask by performing application/exposure and developing photoresist films with subsequent plasma-chemical etching of dielectric films, removal of photoresist mask, plasma-chemical etching of contact film of electrode and semiconductor of p-type conductivity along mask of formed dielectric pattern, forming a dielectric mask by performing application/exposure and developing photoresist films with subsequent plasma-chemical etching of dielectric films, removal of the photoresist mask, by plasma-chemical etching of conductivity semiconductor of i-type by mask of formed dielectric pattern, removal of dielectric mask residues by plasma-chemical etching followed by annealing of formed electrode of electrode contact film, forming a dielectric mask by performing application/exposure and developing photoresist films with subsequent plasma-chemical etching of dielectric films, removal of the photoresist mask, plasma-chemical etching of the n-type conductivity semiconductor by the mask of the formed dielectric pattern and removal of the dielectric mask residues by plasma-chemical etching, and as contact electrode film optically transparent electroconductive film ITO deposited by reactive magnetron sputtering is used.

EFFECT: achieved technical result consists in provision of transparency of ohmic contact of control electrode EOM for optical radiation passing through contact, possibility of forming an EOM using a control electrode with a waveguide self-aligned with the waveguide, as well as to increase percentage yield of EOM fit specimens and improve quality of manufactured contact.

1 cl, 4 dwg