Method for preparing ohmic contact electrode of gallium nitride-based device

A method for preparing an ohmic contact electrode of a gallium nitride (GaN)-based device, comprising following steps:

• step S1:
• growing a first dielectric layer on an upper surface of the GaN-based device;
• step S2:
• implanting at least one of silicon ions or indium ions into a region of the first dielectric layer corresponding to an ohmic contact electrode region of the GaN-based device and into the ohmic contact electrode region;
• step S3:
• growing a second dielectric layer on an upper surface of the first dielectric layer;
• step S4:
• activating the at least one of silicon ions or indium ions using a high temperature annealing process, so as to form an N-type highly doped region;
• step S5:
• respectively removing portions, corresponding to the ohmic contact electrode region, of the first dielectric layer and the second dielectric layer;
• and
• step S6:
• growing a metal layer on an upper surface of the ohmic contact electrode region of the GaN-based device, so as to form the ohmic contact electrode,
• wherein the step S2 comprises:
• step S21:
• applying a first photoresist layer to an upper surface of a portion of the first dielectric layer corresponding to a first region of the GaN-based device, wherein the first region is a region other than the ohmic contact electrode region of the GaN-based device;
• step S22:
• implanting the at least one of silicon ions or indium ions using ion implantation;
• and
• step S23:
• removing the first photoresist layer.