Abstract: A buffer layer structure for the GaN-based semiconductor devices is provided. The buffer layer proposed by the present invention comprises internally at least two sub-layers: a first intermediate layer and a second intermediate layer. Initially, the first intermediate layer is developed on the substrate under a low temperature using silicon-nitride (SixNy, x,y?0). The first intermediate layer is actually a mask having multiple randomly distributed SixNy clusters. Then, a second intermediate layer is developed under a low temperature using aluminum-indium-gallium-nitride (AlwInzGa1-w-zN, 0?w,z<1, w+z?1). The second intermediate layer does not grow directly on top of the first intermediate layer. Instead, the second intermediate layer first grows from the surface of the substrate not covered by the first intermediate layer's mask and, then, overflows to cover the top of the first intermediate layer.

Abstract: A GaN LED structure with a short period superlattice contacting layer is provided. The LED structure comprises, from the bottom to top, a substrate, a double buffer layer, an n-type GaN layer, a short period superlattice contacting layer, an active layer, a p-type shielding layer, and a contacting layer. The feature is to avoid the cracks or pin holes in the thick n-type GaN layer caused during the fabrication of heavily doped (n>1×1019 cm?3) thick n-type GaN contacting layer, so that the quality of the GaN contacting layer is assured. In addition, by using short period heavily silicon doped Al1-x-yGaxInyN (n++-Al1-x-yGaxInyN) to grow a superlattice structure to become a short period superlattice contacting layer structure, which is used as a low resistive n-type contacting layer in a GaInN/GaN MQW LED. In the following steps, it is easier to form an n-type ohmic contacting layer, and the overall electrical characteristics are improved.

Abstract: A number of light-emitting layer structures for the GaN-based LEDs that can increase the lighting efficiency of the GaN-based LEDs on one hand and facilitate the growth of epitaxial layer with better quality on the other hand are provided. The light-emitting layer structure provided is located between the n-type GaN contact layer and the p-type GaN contact layer. Sequentially stacked on top of the n-type GaN contact layer in the following order, the light-emitting layer contains a lower barrier layer, at least one intermediate layer, and an upper barrier layer. That is, the light-emitting layer contains at least one intermediate layer interposed between the upper and lower barrier layers. When there are multiple intermediate layers inside the light-emitting layer, there is an intermediate barrier layer interposed between every two immediately adjacent intermediate layers.

Abstract: An epitaxial structure for GaN-based LEDs to achieve better reverse withstanding voltage and anti-ESD capability is provided. The epitaxial structure has an additional anti-ESD thin layer on top of the p-type contact layer within traditional GaN-based LEDs, which is made of undoped indium-gallium-nitrides (InGaN) or low-band-gap (Eg<3.4 eV), undoped aluminum-indium-gallium-nitrides (AlInGaN). This anti-ESD thin layer greatly improves the GaN-based LEDs' reverse withstanding voltage and resistivity to ESD, which in turn extends the GaN-based LEDs' operation life significantly.

Abstract: A structure and a fabrication method for a nitride semiconductor device are provided so that the device has a lower defect density resulted from incompatible lattice constants between its constituent layers. The nitride semiconductor device contains a substrate, at least a first intermediate layer made of aluminum-gallium-indium-nitride (Al1-x-yGaxInyN) at least a second intermediate layer made of silicon-nitride (SiiNj) or magnesium-nitride (MgmNn), and a nitride epitaxial layer. The second intermediate layer is used to form a mask so that the subsequent epitaxial growth would have a smaller defect density and a better epitaxial quality.

Abstract: Disclosed is a nitride epitaxial layer structure and manufacturing method thereof. The structure includes a substrate, which is used as the basic supporting material, a first immediate layer formed by stacking an appropriate thickness of high temperature aluminum-gallium-indium-nitride (Al1-x-yGaxInyN) on the substrate, a second immediate layer formed by re-crystallizing an appropriate thickness of low temperature aluminum-gallium-indium-nitride (Al1-x-yGaxInyN) stacked on the first immediate layer, and a nitride epitaxial layer formed by stacking nitride epitaxial material on the second immediate layer. The structure so formed can improve and alleviate the problem of excessively high defect density of the low temperature aluminum-gallium-indium-nitride (Al1-x-yGaxInyN), and thus be able to enhance the characteristics of its elements.

Abstract: A gallium-nitride(GaN) based light emitting diode (LED) structure utilizing materials having compatible lattice constant is provided. When aluminum-indium-nitride (AlxIn1-xN, 0<x<1) is used to make the p-type cladding layer within the GaN-based LED structure, the cladding layer has a lattice constant compatible with that of GaN. The active layer's multi-quantum well (MQW) structure, therefore, would not be damaged from the excessive stress resulted from the incompatible lattice constant during the GaN-based LED's epitaxial growth. In addition, AlxIn1-xN (0<x<1) has a wider band gap than that of GaN, which can prevent electrons from overflowing from the MQW active layer. This, in turn, will increase the possibility of forming electron-hole pairs within the MQW active layer. Also due to its wider band gap, AlxIn1-xN (0<x<1) has an effective confinement effect on the photons, which again will increase the GaN-based LED's lighting efficiency.

Abstract: Disclosed is a multi-quantum-well light emitting diode, which makes enormous adjustments and improvements over the conventional light emitting diode, and further utilizes a transparent contact layer of better transmittance efficiency, so as to significantly raise the illuminance of this light emitting diode and its light emission efficiency. The multi-quantum-well light emitting diode has a structure including: substrate, buffer layer, n-type gallium-nitride layer, active light-emitting-layer, p-type cladding layer, p-type contact layer, barrier buffer layer, transparent contact layer, and the n-type electrode layer.

Abstract: Disclosed is a GaN LED structure with a p-type contacting layer using Al—Mg-codoped In1-yGayN grown at low temperature, and having low resistivity. The LED structure comprises, from the bottom to top, a substrate, a buffer layer, an n-type GaN layer, an active layer, a p-type shielding layer, and a p-type contacting layer. In this invention, Mg and Al are used to co-dope the In1-yGayN to grow a low resistive p-type contacting layer at low temperature. Because of the Al—Mg-codoped, the light absorption problem of the p-type In1-yGayN layer is improved. The product, not only has the advantage of convenience of the p-type contacting layer for being manufactured at low temperature, but also shows good electrical characteristics and lowers the operating voltage of the entire element so that the energy consumption during operation is reduced and the yield rate is increased.

Abstract: An epitaxial structure for the GaN-based LED is provided. The GaN-based LED uses a substrate usually made of sapphire or silicon-carbide (SiC). On top of the substrate, the GaN-based LED contains an n-type contact layer made of an n-type GaN-based material. On top of the n-type contact layer, the GaN-based LED further contains a lower barrier layer covering part of the surface of the n-type contact layer. A negative electrode is also on top of and has an ohmic contact with the n-type contact layer in an area not covered by the lower barrier layer. On top of the lower barrier layer, the GaN-based LED then further contains an active layer made of aluminum-gallium-indium-nitride, an upper barrier layer, a p-type contact layer made of a magnesium (Mg)-doped GaN material, and a positive electrode having an ohmic contact with the p-type contact layer, sequentially stacked in this order from bottom to top.