Abstract: A nitride semiconductor structure includes a substrate, a nitride semiconductor layer, and a buffer stack layer between the substrate and the nitride semiconductor layer. The buffer stack layer includes a plurality of metal nitride multilayers repeatedly stacked, wherein each of the metal nitride multilayers consists of a first, a second, and a third metal nitride thin films in sequence, or consists of the first, the third, the second, and the third metal nitride thin films in sequence. The aluminum concentration of the first metal nitride thin film is higher than that of the third metal nitride thin film, and the aluminum concentration of the third metal nitride thin film is higher than that of the second metal nitride thin film.

Abstract: A nitride semiconductor structure includes a substrate, a nitride semiconductor layer, and a buffer stack layer between the substrate and the nitride semiconductor layer. The buffer stack layer includes a plurality of metal nitride multilayers repeatedly stacked, wherein each of the metal nitride multilayers consists of a first, a second, and a third metal nitride thin films in sequence, or consists of the first, the third, the second, and the third metal nitride thin films in sequence. The aluminum concentration of the first metal nitride thin film is higher than that of the third metal nitride thin film, and the aluminum concentration of the third metal nitride thin film is higher than that of the second metal nitride thin film.

Abstract: A method for fabricating a high brightness LED structure is disclosed herein, which comprises at least the following steps. First, a first layered structure is provided by sequentially forming a light generating structure, a non-alloy ohmic contact layer, and a first metallic layer from bottom to top on a side of a first substrate. Then, a second layered structure comprising at least a second substrate is provided. Then, the two-layered structures are wafer-bonded together, with the top side of the second layered structure interfacing with the top side of said first layered structure. The first metallic layer functions as a reflective mirror, which is made of a pure metal or a metal nitride to achieve superior reflectivity, and whose reflective surface does not participate in the wafer-bonding process directly.

Abstract: An LED structure is disclosed herein, which comprises, sequentially arranged in the following order, a light generating structure, a non-alloy ohmic contact layer, a metallic layer, and a substrate. As a reflecting mirror, the metallic layer is made of a pure metal or a metal nitride for achieving superior reflectivity. The non-alloy ohmic contact layer is interposed between the metallic layer and the light generating structure so as to achieve the required ohmic contact. To prevent the metallic layer from intermixing with the non-alloy ohmic contact layer and to maintain the flatness of the reflective surface of the first metallic layer, an optional dielectric layer is interposed between the metallic layer and the non-alloy ohmic contact layer.

Abstract: A LED structure with enhanced side-emitting capability is provided. An embodiment of The LED structure comprises, on top of a substrate, a metallic layer, a non-alloy ohmic contact layer, a thick transparent layer, a light generating structure, sequentially arranged in the this order from bottom to top. The metallic layer functions a reflective mirror and is made of a pure metal or a metal nitride for superior reflectivity. The non-alloy ohmic contact layer is interposed between the light generating structure and the metallic layer so as to achieve the required low resistance electrical conduction. The thick transparent layer extracts a significant portion of the light to the sides of the LED structure. The thick transparent layer, made of a semiconductor material or a dielectric material having an refractive index between 1.5 to 3.5, could be located either above, below or both above and below the light generating structure.

Abstract: A method for fabricating a high brightness LED structure is disclosed herein, which comprises at least the following steps. First, a first layered structure is provided by sequentially forming a light generating structure, a non-alloy ohmic contact layer, and a first metallic layer from bottom to top on a side of a first substrate. Then, a second layered structure comprising at least a second substrate is provided. Then, the two-layered structures are wafer-bonded together, with the top side of the second layered structure interfacing with the top side of said first layered structure. The first metallic layer functions as a reflective mirror, which is made of a pure metal or a metal nitride to achieve superior reflectivity, and whose reflective surface does not participate in the wafer-bonding process directly.

Abstract: An LED structure is disclosed herein, which comprises, sequentially arranged in the following order, a light generating structure, a non-alloy ohmic contact layer, a metallic layer, and a substrate. As a reflecting mirror, the metallic layer is made of a pure metal or a metal nitride for achieving superior reflectivity. The non-alloy ohmic contact layer is interposed between the metallic layer and the light generating structure so as to achieve the required ohmic contact. To prevent the metallic layer from intermixing with the non-alloy ohmic contact layer and to maintain the flatness of the reflective surface of the first metallic layer, an optional dielectric layer is interposed between the metallic layer and the non-alloy ohmic contact layer.