Sintered polycrystalline gallium nitride and its production
AssigneeGeneral Electric Company
InventorsMark P. D'Evelyn, David C. Pender, Suresh S. Vagarali, Dong-Sil Park
Life of this patent
Estimating the term…
Abstract
Polycrystalline gallium nitride (GaN) characterized by having the atomic fraction of gallium ranging from between about 49% to 55%, an apparent density of between about 5.5 and 6.1 g/cm3, and a Vickers hardness of above about 1 GPa. Polycrystalline GaN can be made by hot isostatic pressing (HIPing) at a temperature ranging from about 1150° C. to 1300° C. and a pressure ranging from between about 1 and 10 Kbar. Alternatively, polycrystalline GaN can be made by high pressure/high temperature (HP/HT) sintering at a temperature ranging from about 1200° to 1800° C. and a pressure ranging from about 5 to 80 Kbar.
Claims26
Polycrystalline gallium nitride (CaN), having an apparent density of between about 5.5 and 6.1 g/cm3, a Vickers hardness of above about 1 GPa, eguiaxed grains with an average size of between about 0.01 and 50 μm, and wherein the atomic fraction of gallium ranges from between about 49% to 55%.
A method for making sintered polycrystalline gallium nitride (GaN), which comprises the steps of:
- (a) enclosing and sealing GaN as one or more of powder or a cold-pressed pill, in a non-metallic container;
- (b) subjecting said container to hot isostatic pressing (HIPing) at a temperature ranging from about 1150° C. to 1300° C. and a pressure ranging from between about 1 and 10 Kbar;
- and
- (c) recovering polycrystalline GaN from said container.
A method for making sintered polycrystalline gallium nitride (GaN), which comprises the steps of:
- (a) placing GaN as one or more of powder or a cold-pressed pill in a high pressure/high temperature (HP/HT) reaction cell;
- (b) placing said reaction cell in a HP/HT apparatus;
- (c) subjecting said container to a temperature ranging from about 1200° to 1800° C. and a pressure ranging from about 5 to 80 Kbar;
- and
- (d) recovering polycrystalline GaN from said reaction cell.
Dependencies are inferred from the claim text.