Formosa Epitaxy Incorporation

Liang-Wen Wu

Fen-Ren Chien

Cheng-Tsang Yu

Tzu-Chi Wen

Ru-Chin Tu

Ya-Ping Tsai

Ming-Sheng Chen

Fu-Yu Chang

A LED chip including a substrate, a first type doped semiconductor layer, a second type doped semiconductor layer, a light emitting layer, at least an Indium-doped AlGaN based material layer (0&#x2266;x&#x3c;1) and at least a tunneling junction layer is provided. The first type doped semiconductor layer is disposed on the substrate, and the light emitting layer is disposed between the first type doped semiconductor layer and the second type doped semiconductor layer. The Indium-doped AlGaN based material layer is disposed on at least one surface of the light emitting layer, and the tunneling junction layer is disposed between the Indium-doped AlGaN based material layer and the first type doped semiconductor layer and/or disposed between the Indium-doped AlGaN based material layer and the second type doped semiconductor layer, wherein the Indium-doped AlGaN based material layer and the tunneling junction layer are disposed on the same side of the light emitting layer.

Light emitting diode chip

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 is the light-emitting layer containing 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.

Gallium-nitride based light emitting diode light emitting layer structure

A light-emitting diode chip (LED chip) including a substrate, an electrostatic conducting layer, a first type doped semiconductor layer, an active layer, a second type doped semiconductor layer, a first electrode and a second electrode is provided. The electrostatic conducting layer is disposed on the substrate, while the first type doped semiconductor layer is disposed on a partial area of the electrostatic conducting layer. Besides, the active layer is disposed on a partial area of the first type doped semiconductor layer, while the second type doped semiconductor layer is disposed on the active layer. In addition, the first electrode is disposed on the first type doped semiconductor layer, while the second electrode is disposed on the second type doped semiconductor layer. The LED chip of the present invention has an electrostatic conducting layer, which protects the LED from electrostatic discharge damage (ESD damage).

Light-emitting diode chip

A light-emitting diode structure with transparent window covering layer of multiple films includes one (or several) first transparent covering layer(s) and one (or several) second covering layer(s), which are formed on the outside of the light-emitting diode chip. The light-emitting diode chip can emit light in more than two wavelengths to increase the transmission of the different wavelengths and the taking out efficiency of the light-emitting diode. The first transparent covering layer(s) and the second covering layer(s) are deposited each on the other on the outside of the light-emitting diode chip. The surface of the light-emitting diode with the covering layers is smooth. The contacting parts of the first transparent covering layer(s) and the second covering layer(s) are connected by a strong adhesive force and the contacting parts of the covering layer and light-emitting diode chip also are connected by a strong adhesive force.

Light-emitting diode structure with transparent window covering layer of multiple films

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 traditional structure. The thin layer could be formed using silicon-nitride (SiN), or it could have a superlattice structure either made of layers of SiN and undoped indium-gallium-nitride (InGaN), or made of layers 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.

High-brightness gallium-nitride based light emitting diode structure

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 and a roughened contact layer on top of the masking buffer layer. The masking buffer layer contains randomly distributed clusters made of a group-IV nitride SiN(x,y&#x2267;1), a group-II nitride MgN(w,z&#x2267;1), or a group-III nitride AlInGaN (0&#x2266;s,t&#x3c;1, s+t&#x2266;1) heavily doped with at least a group-II and group-IV element such as Mg and Si. The roughened contact layer, made of AlInGaN (0&#x2266;u,v&#x3c;1, u+v&#x2266;1), starts from the top surface of an underlying second contact layer not covered by the masking buffer layer's clusters, and then grows upward until it passes (but does not cover) the clusters of the masking buffer layer for an appropriate distance. The total internal reflection that could have been resulted from the GaN-based LEDs' higher index of refraction than that of the atmosphere could be avoided.

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.

Gallium-nitride based ultraviolet photo detector

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&#x3c;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.

Gallium-nitride based light-emitting diode structure with high reverse withstanding voltage and anti-ESD capability

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.

A light emitting diode (LED) structure includes a substrate with a surface and cylindrical photonic crystals, a first type doping semiconductor layer, a first electrode, a light emitting layer, a second type doping semiconductor layer and a second electrode. The first type doping semiconductor layer is formed on the substrate to cover the photonic crystals. The light emitting layer, the second type doping semiconductor layer and the second electrode are sequentially formed on a portion of the first type doping semiconductor layer. The first electrode is formed on the other portion of the first type doping semiconductor layer without being covered by the light emitting layer. Because the substrate with photonic crystals can improve the epitaxial quality of the first type doping semiconductor layer and increase the energy of the light forwardly emitting out of the LED, the light emitting efficiency of the LED is effectively enhanced.

Light emitting diode structure having photonic crystals

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&#x3e;1&#xd7;10cm) 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 AlGaInN (n-AlGaInN) 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. It also lowers the operating voltage of the entire element so that the energy consumption during operation is reduced and the yield rate is increased.

Structure of GaN light-emitting diode

Disclosed is a GaN LED structure with a p-type contacting layer using Al&#x2014;Mg-codoped InGaN 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 InGaN to grow a low resistive p-type contacting layer at low temperature. Because of the Al&#x2014;Mg-codoped, the light absorption problem of the p-type InGaN 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.

GaN LED structure with p-type contacting layer grown at low-temperature and having low resistivity

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.

Gallium-nitride based light emitting diode structure with enhanced light illuminance

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 AlInGaNP/AlInGaNP, wherein 0&#x2266;x,y,z,p,q,r&#x2266;1, and AlInGaNPhas an energy gap greater than that of AlInGaNP. The AlInGaNPlayers have increasing thickness and the AlInGaNPlayers have decreasing thickness.

Light-emitting diode structure

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 SiN(x,y&#x2267;1), MgN(w,z&#x2267;1), or AlInGaN (0&#x2266;s,t&#x3c;1, s+t&#x2266;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 AlInGaN (0&#x2266;u,v&#x3c;, u+v&#x2266;) is developed. The p-type roughened contact layer does not grow directly on top of the masking buffer layer. Instead, the p-type roughened contact layer starts from the top surface of the underlying p-type contact layer not covered by the masking buffer layer's clusters. The p-type roughened contact layer then grows upward until it passes (but does not cover) the mask of the masking buffer layer for a specific distance. The total internal reflection that could have been resulted from the GaN-based LEDs' higher index of refraction than that of the atmosphere could be avoided. The GaN-based LEDs according to the present invention therefore have superior external quantum efficiency and luminous efficiency.

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Banciao, Taiwan

Liang-Wen Wu