GaN Devices With Ion Implanted Ohmic Contacts and Method of Fabricating Devices Incorporating the Same
A method for activating implanted dopants and repairing damage to dopant-implanted GaN to form n-type or p-type GaN. A GaN substrate is implanted with n- or p-type ions and is subjected to a high-temperature anneal to activate the implanted dopants and to produce planar n- or p-type doped areas within the GaN having an activated dopant concentration of about 10 18 -10 22 cm −3 . An initial annealing at a temperature at which the GaN is stable at a predetermined process temperature for a predetermined time can be conducted before the high-temperature anneal. A thermally stable cap can be applied to the GaN substrate to suppress nitrogen evolution from the GaN surface during the high-temperature annealing step. The high-temperature annealing can be conducted under N 2 pressure to increase the stability of the GaN. The annealing can be conducted using laser annealing or rapid thermal annealing (RTA).
1 . An epitaxial GaN substrate having at least one selectively formed activated n-type doped region therein;
wherein the activated n-type doped region is planar to a surface of the epitaxial GaN substrate and has a concentration of electrically activated ion-implanted n-type dopants of about 10 18 cm −3 to about 10 22 cm −3 .
2 . The epitaxial GaN substrate according to claim 1 , wherein the n-type dopants are Si or Ge.
3 . An epitaxial GaN substrate having at least one selectively formed activated p-type doped region therein;
wherein the activated p-type doped region is planar to a surface of the epitaxial GaN substrate and has a concentration of electrically activated ion-implanted p-type dopants of about 10 18 cm −3 to about 10 22 cm −3 .
4 . The epitaxial GaN substrate according to claim 3 , wherein the p-type dopants are Mg or Be.