Methods for controllable doping of aluminum nitride bulk crystals
First Claim
Patent Images
1. A method of forming polycrystalline AlN, the method comprising the steps of:
- providing within a crucible a pellet comprising Al, the crucible comprising a foil wrap;
reacting the pellet at a reaction temperature and a reaction pressure with nitrogen gas to form a bulk polycrystalline AlN ceramic, wherein, when the polycrystalline AlN ceramic reaches approximately room temperature after the reaction, the polycrystalline AlN ceramic having properties including (i) less than approximately 1% excess Al and (ii) an oxygen concentration of less than approximately 100 ppm;
after forming the polycrystalline AlN ceramic, and with no sublimation-recondensation treatment of the polycrystalline AlN ceramic therebetween, providing the polycrystalline AlN ceramic and at least a portion of the foil wrap at a first end of and within a crystal growth enclosure;
subliming the polycrystalline AlN ceramic at a formation temperature, the at least a portion of the foil wrap remaining in contact with the polycrystalline AlN ceramic thereduring; and
forming an AlN single crystal at a second end of the crystal growth enclosure.
1 Assignment
0 Petitions
Accused Products
Abstract
Fabrication of doped and undoped stoichiometric polycrystalline AlN ceramics with high purity is accomplished by, for example, reacting Al pellets with nitrogen gas. Such polycrystalline AlN ceramics may be utilized in the fabrication of high purity AlN single crystals, which may be annealed to enhance a conductivity thereof.
187 Citations
42 Claims
-
1. A method of forming polycrystalline AlN, the method comprising the steps of:
-
providing within a crucible a pellet comprising Al, the crucible comprising a foil wrap; reacting the pellet at a reaction temperature and a reaction pressure with nitrogen gas to form a bulk polycrystalline AlN ceramic, wherein, when the polycrystalline AlN ceramic reaches approximately room temperature after the reaction, the polycrystalline AlN ceramic having properties including (i) less than approximately 1% excess Al and (ii) an oxygen concentration of less than approximately 100 ppm; after forming the polycrystalline AlN ceramic, and with no sublimation-recondensation treatment of the polycrystalline AlN ceramic therebetween, providing the polycrystalline AlN ceramic and at least a portion of the foil wrap at a first end of and within a crystal growth enclosure; subliming the polycrystalline AlN ceramic at a formation temperature, the at least a portion of the foil wrap remaining in contact with the polycrystalline AlN ceramic thereduring; and forming an AlN single crystal at a second end of the crystal growth enclosure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42)
-
Specification