Manufacturing method of self-aligned gaas fet using refractory gate of

Abstract

There is disclosed a manufacturing method of self-aligned GaAs FET using refractory gate with dual structure, the manufacturing method of the invention comprising the steps of: forming first photoresist pattern on a GaAs substrate to define an active region and ion-implanting n type impurity in the active region of the GaAs substrate; sequentially depositing a nitrogen-containing silicon layer and a metal layer on the substrate after removal of the first photoresist pattern; forming second photoresist pattern on the metal layer to define a gate; removing the silicon and metal layers using the second photoresist pattern as a gate mask to form the gate with dual structure of the silicon and metal layers; forming third photoresist pattern on the substrate to define source/drain regions after removal of the second photoresist pattern, and ion-implanting high-density impurity in the source/drain regions using the third photoresist pattern and the gate as a source/drain mask; annealing the substrate to make the silicon layer as upper side of the gate into metal-silicon-nitride material, and to make bottom portion of the metal layer as lower side of the gate into metal-silicon-nitride material; and forming ohmic contacts on the source/drain regions, respectively. A GaAs FET according to the invention is provided with a gate having low-resistance and improved schottky characteristics.