APPARATUS AND METHOD FOR GROWTH OF GALLIUM OXIDE CRYSTAL
Apparatuses and methods as described herein can be used to grow a β-Ga 2 O 3 based single crystal using an Edge-defined film fed growth (EFG) method. The method can include bringing a seed crystal in contact with a Ga 2 O 3 base melt, pulling the seed crystal to grow the β-Ga 2 O 3 based single crystal, wherein the β-Ga 2 O 3 based single crystal has a (010) crystallographic orientation as it is being grown, and cooling the β-Ga 2 O 3 based single crystal after it has reached a length that is greater than 40 mm. In one embodiment, the method includes growing the scintillation crystal without defects.
1 . A method of growing a β-Ga 2 O 3 based single crystal using an Edge-defined film fed growth (EFG) method, comprising:
bringing a seed crystal in contact with a Ga 2 O 3 base melt;
pulling the seed crystal to grow the β-Ga 2 O 3 based single crystal, wherein the β-Ga 2 O 3 based single crystal has a (010) crystallographic orientation as it is being grown; and
cooling the β-Ga 2 O 3 based single crystal after it has reached a length that is greater than 40 mm.
2 . The method of claim 1 , wherein the length of the β-Ga 2 O 3 based single crystal is greater than 42 mm.
3 . The method of claim 2 , wherein the length of the β-Ga 2 O 3 based single crystal is less than 500 mm.
4 . The method of claim 2 , wherein the β-Ga 2 O 3 based single crystal has a width that is greater than 25 mm.
5 . The method of claim 4 , wherein the width of the β-Ga 2 O 3 based single crystal is less than 153 mm.
6 . The method of claim 1 , adding a dopant to the Ga 2 O 3 base melt.
7 . The method of claim 6 , wherein the dopant comprises a material selected from the group consisting of Fe, Cu, Ag, Zn, Cd, Al, In, Si, Mg, Ge, and Nb.
8 . The method of claim 6 , wherein the crystal has a dopant distribution that is about the same at a top of the crystal as a bottom of the crystal.
9 . The method of claim 1 , wherein cooling is carried out at a rate not greater than about 300° C./hr.
10 . The method of claim 1 , wherein the β-Ga 2 O 3 based single crystal has a thickness of not less than about 0.2 mm.
11 . The method of claim 10 , wherein the thickness of the β-Ga 2 O 3 based single crystal is not greater than 25 mm.
12 . A Ga 2 O 3 crystal produced by the process, comprising:
bringing a seed crystal in contact with a Ga 2 O 3 base melt;
pulling the seed crystal to grow the β-Ga 2 O 3 based single crystal, wherein the β-Ga 2 O 3 based single crystal has a (010) crystallographic orientation as it is being grown using an edge-defined film fed growth method; and
cooling the β-Ga 2 O 3 based single crystal after it has reached a length that is greater than 40 mm.
13 . The Ga 2 O 3 crystal of claim 12 , wherein the crystal was grown using an Edge-defined film fed growth (EFG) method.
14 . The Ga 2 O 3 crystal of claim 12 , further comprising a dopant, wherein the dopant comprises a material selected from the group consisting of Fe, Cu, Ag, Zn, Cd, Al, In, Si, Mg, Ge, and Nb.
15 . The Ga 2 O 3 crystal of claim 14 , wherein the dopant has a concentration of less than 0.1%.
16 . The Ga 2 O 3 crystal of claim 12 , wherein the crystal is alloyed with a material selected from the group consisting of Al, Bo, Se, In, and other Group 3 elements.
17 . The Ga 2 O 3 crystal of claim 16 , wherein the alloy concentration is greater than 0.1% and less than 70%.
18 . The Ga 2 O 3 crystal of claim 14 , wherein the Ga 2 O 3 crystal has a segregation coefficient for the dopant of less than 1.
19 . The Ga 2 O 3 crystal of claim 12 , wherein the Ga 2 O 3 crystal does not have any twins in the usable area or faceting.
20 . A Ga 2 O 3 single crystal, comprising:
a single gallium oxide crystal sheet having a width greater than 25 mm and a length greater than 40 mm in the (010) crystallographic orientation.