METHOD FOR MANUFACTURING MICROWAVE FIELD TRANSISTOR WITH A SCHOTTKY BARRIER Russian patent published in 2023 - IPC H01L21/335 H01L29/812 B82Y40/00 

FIELD: electronic engineering.

SUBSTANCE: method for manufacturing a microwave field transistor with a Schottky barrier includes forming on of a semi-insulating substrate with an active layer of at least one pair of single source and drain electrodes, with a channel between them, on the front side, by means of lithography and vacuum deposition of a metal layer or a system of metal layers forming ohmic contacts in the area of the source and drain electrodes, forming a dielectric layer, on the active layer of the semi-insulating substrate on the side of the source electrode, from a material with a low permittivity, by means of plasma chemical deposition method, forming topology of the gate electrode, on the dielectric layer by means of lithography and etching, forming a groove under the gate, in the channel, by means of lithography and isotropic etching, forming a gate electrode asymmetrically towards the single source electrode, by means of lithography and vacuum deposition of a metal layer or a system of metal layers creating the Schottky barrier, the latter are applied at a set angle between the front side of the semi-insulating substrate and the flux vector of the metal layer deposited towards the source electrode. In addition, the dielectric layer is formed simultaneously, from the side of the single drain electrode, from the same material, with its own permittivity less than 8.0, with a thickness of 0.1-0.25×10^-6 m, with the temperature of the semi-insulating substrate at 200-350°C. When forming topology of the gate electrode on the dielectric layer, by means of lithography and anisotropic reactive ion etching in a gas system composed of sulphur hexafluoride SF₆ and oxygen O₂, until complete removal dielectric layer in the area of the latter, formation of a groove for the gate electrode, in the channel, is carried out by means of lithography and isotropic etching methods. When forming the gate electrode, by means of lithography and vacuum deposition of a metal layer or a system of metal layers creating a Schottky barrier, in the course of technological operations process (lithography method), only one resistive positive mask with resolution values around 1000.0 lines/mm is used, ensuring resolution of more than 700.0 lines/mm, the resistive mask is formed from two layers of materials with different qualitative composition of components and solubility values and/or chemical reactivity of the light-sensitive component of the material of the lower layer, exceeding these parameters of the upper layer of the resist mask by 2.0-2.5 times, and the length of the gate electrode is set based on the specified ratio.

EFFECT: yield increase, improvement of reproducibility of the main electrical parameters of the microwave, simplification of the manufacturing method while maintaining the values of the main electrical parameters of the microwave.

7 cl, 1 tbl, 1 dwg