METHOD OF MAKING MULTILAYER OHMIC CONTACT TO n-GaAs Russian patent published in 2010 - IPC H01L21/28 B82B3/00 

FIELD: physics.

SUBSTANCE: in the method of making a multilayer ohmic contact to n-GaAs, involving creation of a double-layer photoresist mask on the surface of a wafer, layerwise deposition of films based on Ge and Au with film thickness corresponding to eutectic composition, and common thickness of 50-300 nm, deposition of Ni-based films with thickness of 10-100 nm, diffusion barrier films with thickness of 10-200 nm, and a top Au film having thickness of 10-1000 nm, removal of the double-layer photoresist mask and thermal treatment of the contacts in an inert atmosphere, deposition of Ge, Au, Ni and Au films onto the a GaAs surface is performed with flight angle of atoms of these materials relative the normal to the surface of the wafer lying in the range of 0-2°, and deposition of a diffusion barrier film based on Ti, Ta, W, Cr, Pt, Pd, TiW, TIN, TaN or WN is performed with flight angle atoms β=n×α, where α is flight angle of Ge, Au, Ni atoms, n=2-10. Thermal treatment is carried out for 1-30 minutes or in a fast thermal annealing device for 30-300 seconds.

EFFECT: low value of reduced contact resistance of the multilayer ohmic contacts.

2 cl, 6 dwg