METHOD FOR MANUFACTURING A HIGH-FREQUENCY TRANSISTOR WITH AN ADDITIONAL ACTIVE FIELD ELECTRODE Russian patent published in 2019 - IPC H01L21/335 

FIELD: electronic equipment.

SUBSTANCE: invention relates to electronic engineering and is intended to create powerful field-effect transistors with a Schottky gate and an additional active field ("Field plate" – FP) electrode. It can be used in high-power microwave transistors based on nitride (GaN) heteroepitaxial structures for amplifying field effects associated with increase in the breakdown voltage U_br, prevention of current "collapse" and reduction of operating temperature of channel T_c. Disclosed is a method of manufacturing a powerful field-effect transistor with an active field electrode, which includes: selecting an active region, creating ohmic contacts of the source and drain, applying a dielectric mask, lithography for opening the windows, which are located closer to the drain edges of which determine the location of Schottky gates in the manufactured transistor, removal of the material of the dielectric mask in the windows of the resistive mask, and then the resist itself, formation through a new lithography in a new resistive layer of the gate opening surrounding the Schottky gate determining locations of the edge of the windows of the dielectric mask, sputtering of the gate metal coating, performing explosion operation and obtaining Z-shaped Schottky gate, removing dielectric mask from under Z-shaped cap of gate, repeated application of protective dielectric with formation of air or other cavities under head of Z-gate, formed above the gate and displaced to drain by active connected air bridges with source of field FP-electrode. Novelty is that an air gap is formed between the FP-electrode and the Z-shaped gate, which leads to reduction of parasitic gate-source capacitance and improvement of microwave characteristics of the transistor. To obtain the required gap between the FP-electrode and the gate, or between the FP-electrode and adjacent to the Z-gate on the side of drain by the channel surface, dielectric supports of the specified height are formed.

EFFECT: advantage of the proposed method of field-effect transistor manufacturing is significant reduction of gate-source capacitance and improvement of microwave characteristics of the transistor.

1 cl, 1 dwg