METHOD OF FORMING T-SHAPED GATE Russian patent published in 2019 - IPC H01L21/18 

FIELD: physics.

SUBSTANCE: invention relates to the technology of microelectronics, specifically to the technology of producing UHF monolithic integrated circuits based on semiconductor compounds of type A_IIIB_V, in particular, to creation of heterostructured microwave transistors with high electron mobility. On the surface of the semiconductor wafer by magnetron evaporation in a vacuum at residual pressure less than p = 5×10^-6 torus deposition of film of barrier-forming layer based on titanium with thickness of 30 nm. Further, a two-layer mask based on LOR5B/495PMMA resins is formed by centrifugation. Each resist layer is applied onto the substrate by centrifugation, followed by drying at 180 °C for 5 minutes. Exposure is carried out using a system of electron-beam nanolithography Raith-150^TWO with electron energy of 30 keV. Upper layer of the resist of type 495PMMA is shown in a solution of methylisobutyl ketone (MIBK) with isopropyl alcohol (IPA) (1:1) for 60 s, a lower layer of LOR5B followed by washing in isopropyl alcohol and drying in a stream of nitrogen. Then, metallization of the T-shaped shutter on the basis of Pt/Au films (25/400 nm) is performed by electron-beam correction and vacuum. After the plate is removed from the vacuum chamber, removal of the resistive mask is performed, followed by selective plasma-chemical etching of the film of the Ti-based barrier-forming layer on the solid Au mask on the surface of the plate.

EFFECT: technical result consists in improvement of thermal stability of electrical characteristics of T-shaped gate, formed by projection lithography methods when using "slot" in dielectric.

5 cl, 4 dwg