Low defect density (Ga, Al, In)N and HVPE process for making same
AssigneeAdvanced Technology Materials, Inc.
InventorsRobert P. Vaudo, Vivek M. Phanse, Michael A. Tischler
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Abstract
A low defect density (Ga,Al,In)N material. The (Ga, Al, In)N material may be of large area, crack-free character, having a defect density as low as 3×106 defects/cm2 or lower. Such (Ga,Al,In)N material is useful as a substrate for epitaxial growth of Group III-V nitride device structures thereon.
Claims17
A method of forming a GaN material, comprising growing the GaN material by a HVPE growth process using NH3, HCl and Ga as reactants, wherein the HVPE growth process is carried out at a temperature in the range of from about 985° C. to about 1010° C., at a growth rate of from about 50 to about 150 μm per hour, a pressure of from about 10 to about 800 torr, and a NH3/HCl ratio of from about 20 to about 40, so that the formed GaN material includes dislocations that are predominantly angled with respect to the growth direction by a tilt angle that is in the range of 0.1 to about 40, and wherein the formed GaN material has a dislocation defect density of 107/ cm2 or lower.
An HVPE process for forming a low defect density (Ga, Al, In)nitride material, said process comprising (1) a first stage comprising depositing (Ga, Al, In)N material on a substrate at a temperature in the range of from about 950° C. to about 1020° C., and forming a (Ga, Al, In)N material having a dislocation density of 107 defects/cm2 or lower, with said (Ga, Al, In)N material having pits on an upper surface of said material at the conclusion of the first stage of the process, and (2) a second stage comprising depositing (Ga, Al, In)nitride material on the (Ga, Al, In)nitride material that was deposited in the first stage of the process, wherein said second stage is conducted at a temperature in the range of from about 1020° C. to about 1250° C. for sufficient time to at least partially fill pits formed on the surface of the (Ga, Al, In)N material in the first stage of the process.
Dependencies are inferred from the claim text.