Abstract: A structure for a gallium-nitride (GaN) based ultraviolet photo detector is provided. The structure contains an n-type contact layer, a light absorption layer, a light penetration layer, and a p-type contact layer, sequentially stacked on a substrate from bottom to top in this order. The layers are all made of aluminum-gallium-indium-nitride (AlGaInN) compound semiconductors. By varying the composition of aluminum, gallium, and indium, the layers, on one hand, can achieve the desired band gaps so that the photo detector is highly responsive to ultraviolet lights having specific wavelengths. On the other hand, the layers have compatible lattice constants so that problems associated with excessive stress are avoided and high-quality epitaxial structure is obtained. The structure further contains a positive electrode, a light penetration contact layer, and an anti-reflective coating layer on top of the p-type contact layer, and a negative electrode on the n-type contact layer.

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 GaN-based LED structure is provided so that the brightness and lighting efficiency of the GaN-based LED are enhanced effectively. The greatest difference between the GaN-based LEDs according to the invention and the prior arts lies in the addition of a thin layer on top of the p-type contact layer within the traditional structure. The thin layer could be formed using silicon-nitride (SiN), or it could have a superlattice structure made of either SiN and undoped indium-gallium-nitride (InGaN), or SiN and undoped aluminum-gallium-indium-nitride (AlGaInN), respectively. Because of the use of SiN in the thin layer, the surfaces of the GaN-based LEDs would be micro-roughened, and the total internal reflection resulted from the GaN-based LEDs' higher index of refraction than the atmosphere could be avoided. The GaN-based LEDs according to the invention therefore have superior external quantum efficiency and lighting efficiency.

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: A gallium-nitride based light-emitting diode structure includes a digital penetration layer to raise its reverse withstanding voltage and electrostatic discharge. The digital penetration layer is formed by alternate stacking layers of AlxInyGa1-x-yNzP1-z/AlpInqGa1-p-qNrP1-r, wherein 0?x,y,z,p,q,r?1, and AlxInyGa1-x-yNzP1-z has an energy gap greater than that of AlpInqGa1-p-qNrP1-r. The AlxInyGa1-x-yNzP1-z layers have increasing thickness and the AlpInqGa1-p-qNzP1-r layers have decreasing thickness.

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: A structure for a gallium-nitride (GaN) based ultraviolet photo detector is provided. The structure contains an n-type contact layer, a light absorption layer, a light penetration layer, and a p-type contact layer, sequentially stacked on a substrate from bottom to top in this order. The layers are all made of aluminum-gallium-indium-nitride (AlGaInN) compound semiconductors. By varying the composition of aluminum, gallium, and indium, the layers, on one hand, can achieve the desired band gaps so that the photo detector is highly responsive to ultraviolet lights having specific wavelengths. On the other hand, the layers have compatible lattice constants so that problems associated with excessive stress are avoided and high-quality epitaxial structure is obtained. The structure further contains a positive electrode, a light penetration contact layer, and an anti-reflective coating layer on top of the p-type contact layer, and a negative electrode on the n-type contact layer.

Abstract: A GaN-based LED structure is provided so that the brightness and luminous efficiency of the GaN-based LED are enhanced effectively. The greatest difference between the GaN-based LEDs according to the invention and the prior arts lies in the addition of a masking buffer layer on top of the p-type contact layer and a p-type roughened contact layer on top of the masking buffer layer. The masking buffer layer could be formed using MOCVD to deposit SixNy (x,y?1), MgwNz (w,z?1), or AlsIntGa1-s-tN (0?s,t<1, s+t?1) heavily doped with Si and/or Mg. The masking buffer layer is actually a mask containing multiple randomly distributed clusters. Then, on top of the masking buffer layer, a p-type roughened contact layer made of p-type AluInGa1-u-vN (0?u,v<1, u+v?1) is developed. The p-type roughened contact layer does not grow directly on top of the masking buffer layer.

Abstract: A GaN-based LED structure is provided so that the brightness and lighting efficiency of the GaN-based LED are enhanced effectively. The greatest difference between the GaN-based LEDs according to the invention and the prior arts lies in the addition of a thin layer on top of the p-type contact layer within the traditional structure. The thin layer could be formed using silicon-nitride (SiN), or it could have a superlattice structure made of either SiN and undoped indium-gallium-nitride (InGaN), or SiN and undoped aluminum-gallium-indium-nitride (AlGaInN), respectively. Because of the use of SiN in the thin layer, the surfaces of the GaN-based LEDs would be micro-roughened, and the total internal reflection resulted from the GaN-based LEDs' higher index of refraction than the atmosphere could be avoided. The GaN-based LEDs according to the invention therefore have superior external quantum efficiency and lighting efficiency.

Abstract: A gallium-nitride based light-emitting diode structure includes a digital penetration layer to raise its reverse withstanding voltage and electrostatic discharge. The digital penetration layer is formed by alternate stacking layers of AlxInyGa1-x-yNzP1-z/AlpInqGa1-p-qNrP1-r, wherein 0?x,y,z,p,q,r?1, and AlxInyGa1-x-yNzP1-z has an energy gap greater than that of AlpInqGa1-p-qNrP1-r. The AlxInyGa1-x-yNrP1-z layers have increasing thickness and the AlpInqGa1-p-qNrP1-r layers have decreasing thickness.

Abstract: A structure for the n-type contact layer in the GaN-based MQW LEDs is provided. Instead of using Si-doped GaN as commonly found in conventional GaN-based MQW LEDs, the n-type contact layer provided by the present invention achieves high doping density (>1×1019 cm?3) and low resistivity through a superlattice structure combining two types of materials, AlmInnGa1-m-nN and AlpInqGa1-p-qN (0?m,n<1, 0<p,q<1, p+q?1, m<p), each having its specific composition and doping density. In addition, by controlling the composition of Al, In, and Ga in the two materials, the n-type contact layer would have a compatible lattice constant with the substrate and the epitaxial structure of the GaN-based MQW LEDs. This n-type contact layer, therefore, would not chap from the heavy Si doping, have a superior quality, and reduce the difficulties of forming n-type ohmic contact electrode. In turn, the GaN-based MQW LEDs would require a lower operation voltage.

Abstract: A GaN LED structure with a short period superlattice digital 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 digital 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>1×1019cm?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 doped silicon Al1-x-yGaxInyN (n++-Al1-x-yGaxInyN) to grow a superlattice structure to become a short period superlattice digital 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 GaN-based LED structure is provided so that the brightness and luminous efficiency of the GaN-based LED are enhanced effectively. The greatest difference between the GaN-based LEDs according to the invention and the prior arts lies in the addition of a masking buffer layer on top of the p-type contact layer and a p-type roughened contact layer on top of the masking buffer layer. The masking buffer layer could be formed using MOCVD to deposit SixNy (x,y?1), MgwNz (w,z?1), or AlsIntGa1-s-tN (0?s,t<1, s+t?1) heavily doped with Si and/or Mg. The masking buffer layer is actually a mask containing multiple randomly distributed clusters. Then, on top of the masking buffer layer, a p-type roughened contact layer made of p-type AluInvGa1-u-vN (0?u,v<1, u+v?1) is developed. The p-type roughened contact layer does not grow directly on top of the masking buffer layer.

Abstract: A structure for the n-type contact layer in the GaN-based MQW LEDs is provided. Instead of using Si-doped GaN as commonly found in conventional GaN-based MQW LEDs, the n-type contact layer provided by the present invention achieves high doping density (>1×1019 cm?3) and low resistivity through a superlattice structure combining two types of materials, AlmInnGa1-m-nN and AlpInqGa1-p-qN (0?m, n<1, 0<p, q<1, p+q?1, m<p), each having its specific composition and doping density. In addition, by controlling the composition of Al, In, and Ga in the two materials, the n-type contact layer would have a compatible lattice constant with the substrate and the epitaxial structure of the GaN-based MQW LEDs. This n-type contact layer, therefore, would not chap from the heavy Si doping, have a superior quality, and reduce the difficulties of forming n-type ohmic contact electrode. In turn, the GaN-based MQW LEDs would require a lower operation voltage.

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: 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: 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.