Method of growing group iii nitride crystals
AssigneesSeoul Semiconductor Co., Ltd., SixPoint Materials, Inc.
InventorsTadao Hashimoto, Edward Letts, Sierra Hoff
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Abstract
The present invention provides a method of growing an ingot of group III nitride. Group III nitride crystals such as GaN are grown by the ammonothermal method on both sides of a seed to form an ingot and the ingot is sliced into wafers. The wafer including the first-generation seed is sliced thicker than the other wafers so that the wafer including the first-generation seed does not break. The wafer including the first-generation seed crystal can be used as a seed for the next ammonothermal growth.
Claims24
A method of growing an ingot of group III nitride composed of GaxAlyIn1-x-yN (0≦x≦1, 0≦x+y≦1) comprising
- (a) growing a first group III nitride crystal on a first face of a seed;
- and
- (b) growing a second group III nitride crystal on a second face of the seed;
- wherein the seed comprises
- (1) a first layer comprised of
- a) a first group III nitride wafer having
- 1) a first crystalline lattice orientation and
- 2) a first edge adjacent to a first face and a second face of the first group III nitride wafer
- b) a second group III nitride wafer having
- 1) a second crystalline lattice orientation and
- 2) a first edge adjacent to a first face and a second face of the second group III nitride wafer
- c) the second group III nitride wafer having its first edge adjacent to the first edge of the first group III nitride wafer in the first layer and
- d) the first crystalline lattice orientation being the same as the second crystalline lattice orientation in the first layer,
- (2) a second layer comprises
- a) a third group III nitride wafer having
- 1) a third crystalline lattice orientation and
- 2) a first edge adjacent to a first face and a second face of the third group III nitride wafer
- b) a fourth group III nitride wafer having
- 1) a fourth crystalline lattice orientation and
- 2) a first edge adjacent to a first face and a second face of the fourth group III nitride wafer
- c) the third group III nitride wafer having its first edge adjacent to the first edge of the fourth group III nitride wafer in the second layer and
- d) the third crystalline lattice orientation being the same as the fourth crystalline lattice orientation in the second layer, and
- (3) wherein the first edge of first group III nitride wafer of the first layer is positioned at the first face of the third group III nitride wafer of the second layer
- (4) wherein the first edge of the second group III nitride wafer of the first layer is positioned at the first face of the third group III nitride wafer of the second layer
- (5) wherein the first edge of the third group III nitride wafer of the second layer is positioned at the first face of the second group III nitride wafer of the first layer
- (6) wherein the first edge of the fourth group III nitride wafer of the second layer is positioned at the first face of the second group III nitride wafer of the first layer, and
- (7) wherein the crystal lattice orientation of the first wafer of the first layer matches the crystal lattice orientation of the third wafer of the second layer.
A group III nitride seed having a first uncracked surface and a second uncracked surface comprising a first layer of group III nitride wafers, the first layer having a first face and a second face, and a second layer of group III nitride wafers, the second layer having a first face and a second face, the first face of the first layer facing the first face of the second layer, the second face of the first layer having at least one crack, and overlying the second face of the first layer a sufficient thickness of group III nitride to provide said first uncracked surface.
A group III nitride seed composed of two or more wafers contacting one another along a face rather than along an edge of the seeds, and wherein at least one of the wafers is (a) a wafer having a surface crack;
- (b) a cracked wafer formed using HVPE and therefore having a value of density of line defects (e.g. dislocations) and grain boundaries greater than 105 cm−2;
- (c) a wafer formed using ammonothermal method;
- and (d) positioned so that said at least one wafer is offset from the second wafer so that an edge of the first wafer does not align with an edge of the second wafer.
An ingot formed of a first layer having a first and a second seed and a second layer having a third and a fourth seed, wherein an edge of the first seed is not aligned with a corresponding edge of any seed in the second layer.
A seed composed of a first group III nitride wafer secured to a second group III nitride wafer, wherein the first wafer has a crack propagating from a first face to a second face of the first wafer, wherein the second wafer has a crack propagating from a first face to a second face of the second wafer, and wherein the seed has a regular shape from which an ingot may be formed.
An ingot of crystalline group III nitride having the formula GaxAlyIn1-x-yN (0≦x≦1, 0≦x+y≦1) and having a first face and a second face, the first face having a crystalline structure polarity and the second face also having said crystalline structure polarity.
Dependencies are inferred from the claim text.