摘要:
An off-axis cut of a nonpolar III-nitride wafer towards a polar (−c) orientation results in higher polarization ratios for light emission than wafers without such off-axis cuts. A 5° angle for an off-axis cut has been confirmed to provide the highest polarization ratio (0.9) than any other examined angles for off-axis cuts between 0° and 27°.
摘要:
A nonpolar III-nitride film grown on a miscut angle of a substrate. The miscut angle towards the direction is 0.75° or greater miscut and less than 27° miscut towards the direction. Surface undulations are suppressed and may comprise faceted pyramids. A device fabricated using the film is also disclosed. A nonpolar III-nitride film having a smooth surface morphology fabricated using a method comprising selecting a miscut angle of a substrate upon which the nonpolar III-nitride films are grown in order to suppress surface undulations of the nonpolar III-nitride films. A nonpolar III-nitride-based device grown on a film having a smooth surface morphology grown on a miscut angle of a substrate which the nonpolar III-nitride films are grown. The miscut angle may also be selected to achieve long wavelength light emission from the nonpolar film.
摘要:
The present invention provides a method for growing group III-nitride crystals wherein the group III-nitride crystal growth occurs on an etched seed crystal. The etched seed is fabricated prior to growth using a temperature profile which produces a high solubility of the group III-nitride material in a seed crystals zone as compared to a source materials zone. The measured X-ray diffraction of the obtained crystals have significantly narrower Full Width at Half Maximum values as compared to crystals grown without etch back of the seed crystal surfaces prior to growth.
摘要:
A technique for growing high quality bulk hexagonal single crystals using a solvo-thermal method, and a technique for achieving the high quality and high growth rate at the same time. The crystal quality strongly depends on the growth planes, wherein a nonpolar or semipolar seed surface such as {10-10}, {10-11}, {10-1-1}, {10-12}, {10-1-2}, {11-20}, {11-22}, {11-2-2} gives a higher crystal quality as compared to a c-plane seed surface such as (0001) and (000-1). Also, the growth rate strongly depends on the growth planes, wherein a semipolar seed surface such as {10-12}, {10-1-2}, {11-22}, {11-2-2} gives a higher growth rate. High crystal quality and high growth rate are achievable at the same time by choosing the suitable growth plane. The crystal quality also depends on the seed surface roughness, wherein high crystal quality is achievable when the nonpolar or semipolar seed surface RMS roughness is below 100 nm; on the other hand, the crystal grown from the Ga-face or N-face results in poor crystal quality, even though grown from an atomically smooth surface.
摘要:
A nonpolar III-nitride film grown on a miscut angle of a substrate. The miscut angle towards the direction is 0.75° or greater miscut and less than 27° miscut towards the direction. Surface undulations are suppressed and may comprise faceted pyramids. A device fabricated using the film is also disclosed. A nonpolar III-nitride film having a smooth surface morphology fabricated using a method comprising selecting a miscut angle of a substrate upon which the nonpolar III-nitride films are grown in order to suppress surface undulations of the nonpolar III-nitride films. A nonpolar III-nitride-based device grown on a film having a smooth surface morphology grown on a miscut angle of a substrate which the nonpolar III-nitride films are grown. The miscut angle may also be selected to achieve long wavelength light emission from the nonpolar film.
摘要:
An off-axis cut of a nonpolar III-nitride wafer towards a polar (−c) orientation results in higher polarization ratios for light emission than wafers without such off-axis cuts. A 5° angle for an off-axis cut has been confirmed to provide the highest polarization ratio (0.9) than any other examined angles for off-axis cuts between 0 and 27°.
摘要:
A method of obtaining a hexagonal würtzite type epitaxial layer with a low impurity concentration of alkali-metal by using a hexagonal würtzite substrate possessing a higher impurity concentration of alkali-metal, wherein a surface of the substrate upon which the epitaxial layer is grown has a crystal plane which is different from the c-plane.
摘要:
A nonpolar III-nitride film grown on a miscut angle of a substrate, in order to suppress the surface undulations, is provided. The surface morphology of the film is improved with a miscut angle towards an a-axis direction comprising a 0.15° or greater miscut angle towards the a-axis direction and a less than 30° miscut angle towards the a-axis direction.
摘要:
A method to improve the crystal purity of a group-I11 nitride crystal grown in an ammonothermal growth system by removing any undesired material (i.e., impurities) from within the system prior to, in-between, or after the growth steps for the group-I11 nitride crystal. Impurities are removed from the ammonothermal growth system by first bringing the impurities into solution and then removing part or all of the solution from the growth system. The result is a high purity group-I11 nitride crystal grown in the ammonothermal growth system.
摘要:
A nonpolar III-nitride film grown on a miscut angle of a substrate, in order to suppress the surface undulations, is provided. The surface morphology of the film is improved with a miscut angle towards an a-axis direction comprising a 0.15° or greater miscut angle towards the a-axis direction and a less than 30° miscut angle towards the a-axis direction.