CN107819059A - Nitride semiconductor structure and semiconductor light emitting element - Google Patents

Abstract

The invention relates to a nitride semiconductor structure and a semiconductor light-emitting element. The nitride semiconductor structure is mainly provided with a light emitting layer between an N-type semiconductor layer and a P-type semiconductor layer, a quaternary carrier active layer is arranged between the light emitting layer and the P-type semiconductor layer, and the quaternary carrier active layer is aluminum indium gallium Al nitride_xIn_yGa_1‑x‑yN, wherein x and y are 0<x<1、0<y<1、0<x+y<A value of 1. The semiconductor light-emitting element comprises the nitride semiconductor structure on a substrate, and an N-type electrode and a P-type electrode which are matched with each other to provide electric energy. Therefore, compared with the known P-AlGaN electron blocking layer, the nitride semiconductor structure and the semiconductor light-emitting element can improve the effect that holes enter the multi-quantum well structure, and simultaneously achieve the purpose of inhibiting electrons from escaping to enter the P-type semiconductor layer, so that the combination probability of the holes is increased, and the light-emitting efficiency is further improved.

Description

Nitride semiconductor structure and semiconductor light emitting element

related divisional application

This application is a divisional application of a patent with an application date of January 25, 2013, an application number of 201310028759.6, and an invention title of "Nitride Semiconductor Structure and Semiconductor Light-Emitting Element".

technical field

The present invention relates to a nitride semiconductor structure and a semiconductor light-emitting element, in particular to a quaternary carrier in which aluminum indium gallium nitride Al _x In _y Ga _1-xy N is arranged between a light-emitting layer and a P-type semiconductor layer A nitride semiconductor structure of an active layer and a semiconductor light-emitting element belong to the technical field of semiconductors.

Background technique

In recent years, due to the advancement of epitaxy and process technology, light-emitting diodes have become one of the most promising solid-state lighting sources; among them, light-emitting diodes with gallium nitride (GaN) as the main manufacturing material have now become solid-state lighting (Solid- State lighting (SSL) is one of the important components in the construction; gallium nitride LED has become one of the latest optoelectronic semiconductor materials due to its advantages of small size, no mercury pollution, high luminous efficiency and long life, and its luminous The wavelength almost covers the range of visible light, making it a very potential material for light-emitting diodes.

Generally speaking, a gallium nitride LED first forms a buffer layer on the substrate, and then epitaxially grows an N-type semiconductor layer, a light-emitting layer, and a P-type semiconductor layer on the buffer layer; then, using lithography and etching processes removing part of the P-type semiconductor layer and part of the light-emitting layer until a part of the N-type semiconductor layer is exposed; then, forming an N-type electrode and a P-type electrode on the exposed part of the N-type semiconductor layer and the P-type semiconductor layer respectively , and produce a light-emitting diode; wherein, the light-emitting layer is a multiple quantum well structure (MQW), and the multiple quantum well structure includes quantum well layers (well) and quantum barrier layers (barrier) that are alternately arranged in a repeated manner, because quantum The well layer has a relatively lower energy gap than the quantum barrier layer, so that each quantum well layer in the above-mentioned multiple quantum well structure can limit electrons and holes quantum mechanically, causing electrons and holes to flow from the N-type semiconductor layer respectively. It is injected into the P-type semiconductor layer and combined in the quantum well layer to emit photons.

However, the luminous efficiency of the aforementioned light-emitting diodes is affected by many factors (such as current crowding, dislocation, etc.); theoretically, the luminous efficiency of a light-emitting diode depends on the external quantum efficiency and its own Internal quantum efficiency (internal quantum efficiency) and light-extraction efficiency (light-extraction efficiency); the so-called internal quantum efficiency is determined by the characteristics and quality of the material, and the light-extraction efficiency is the ratio of radiation emitted from the inside of the component to the surrounding air. The light extraction efficiency depends on the loss that occurs when the radiation leaves the interior of the element. One of the main reasons for the above loss is that the semiconductor material forming the surface layer of the element has a high refraction coefficient (refraction coefficient), which causes light to pass through the surface of the material Total reflection (total reflection) cannot be emitted, and if the light extraction efficiency is improved, the external quantum efficiency of the semiconductor light-emitting element will also be improved; therefore, in recent years, in order to improve the internal quantum efficiency and light extraction efficiency, developed Many technologies, such as using Indium Tin Oxide (ITO) as a current transport layer, using a flip-chip structure (flip-chip), using a patterned (PSS) sapphire substrate, and using a current block layer (current block layer) ; CBL) etc.; wherein, in the technology of improving the internal quantum efficiency, there is also a P-type carrier blocking layer with a high energy gap (band gap) between the multiple quantum well structure and the P-type semiconductor layer, which is also It can be called electron blocking layer (electronblocking layer, EBL), so that more carriers are confined in the quantum well layer, so as to increase the probability of electron hole recombination, increase the luminous efficiency, and then achieve the effect of improving the brightness of light emitting diodes .

The existing electron blocking layer is formed of a P-type AlGaN layer with a relatively large energy gap, thereby preventing electrons injected from the N-type semiconductor layer from overflowing into the P-type semiconductor layer, so that the electrons can be effectively confined in the quantum well layer , to improve the internal quantum efficiency of light-emitting diodes; however, although the electron blocking layer of P-AlGaN has a considerable energy gap to prevent electron overflow, it also leads to a relatively poor effect of hole injection into the light-emitting layer; moreover , because the multiple quantum well structure is generally formed by the quantum well layer of InGaN and the quantum barrier layer of GaN, but in essence, the electron blocking layer of P-AlGaN and the quantum barrier layer of GaN have a very high lattice mismatch , so that the InGaN quantum well layer will be seriously affected by compressive stress due to lattice mismatch, and this compressive stress changes the energy band structure of each quantum well layer, so that the electrons and holes in the quantum well layer Spatially separated from each other, resulting in a reduction in the luminous efficiency of the light-emitting diode; moreover, the above-mentioned compressive stress will also deteriorate the interface characteristics between the adjacent GaN quantum barrier layer and the InGaN quantum well layer, thereby losing carriers at the interface, and also Affects the luminous efficiency of light-emitting diodes.

In view of the fact that the existing nitride semiconductor light-emitting elements still have many deficiencies in actual implementation, it is still one of the problems to be solved urgently in this field to develop a novel nitride semiconductor structure and semiconductor light-emitting element.

Contents of the invention

In order to solve the above-mentioned technical problems, the main purpose of the present invention is to provide a nitride semiconductor structure, which is configured by a quaternary of aluminum indium gallium nitride Al _x In _y Ga _1-xy N between the light-emitting layer and the P-type semiconductor layer. The carrier active layer is used to enhance the effect of holes entering the multiple quantum well structure, and at the same time, it can also achieve the purpose of preventing electrons from escaping into the P-type semiconductor layer, so that the combination probability of electrons and holes is increased to obtain good luminous efficiency.

To achieve the above object, the present invention provides a nitride semiconductor structure, which includes an N-type semiconductor layer and a P-type semiconductor layer, a light-emitting layer is arranged between the N-type semiconductor layer and the P-type semiconductor layer, and the light-emitting layer and the P-type semiconductor layer A quaternary carrier active layer is arranged between the semiconductor layers, and the quaternary carrier active layer is aluminum indium gallium nitride Al _x In _y Ga _1-xy N, where x and y satisfy 0<x<1, 0< The value of y<1, 0<x+y<1. Wherein, preferably, the range of x of the quaternary carrier active layer is 0<x≤0.4; moreover, preferably, the range of y of the quaternary carrier active layer is 0<y≤0.2.

According to a specific embodiment of the present invention, preferably, in the above-mentioned nitride semiconductor structure, the light-emitting layer has a multiple quantum well structure, and the multiple quantum well structure can be composed of a well layer of indium gallium nitride and a barrier layer of gallium nitride. The energy gap of the quaternary carrier active layer formed by alternating stacks and adjacent to the last well layer of the multiple quantum well structure is greater than the energy gap of the barrier layer of the multiple quantum well structure; wherein, more preferably, the quaternary The energy gap of the carrier active layer is 1%-15% higher than that of the barrier layer. Therefore, compared with the known P-AlGaN electron blocking layer, it not only improves the effect of holes entering the multiple quantum well structure, but also achieves the purpose of inhibiting electrons from escaping into the P-type semiconductor layer, so that the probability of electrons and holes combining increase to further enhance the luminous efficiency.

According to a specific embodiment of the present invention, preferably, in the above-mentioned nitride semiconductor structure, the quaternary carrier active layer is doped with elements of the fourth main group at a concentration of 10 ¹⁶ -10 ¹⁹ cm ^-3 ; more preferably , the fourth main group element is carbon; thus, the fourth main group element is used to replace the pentavalent nitrogen atom to have one more positively charged hole, so that the quaternary carrier active layer can have a high hole concentration to Provide more holes into the light-emitting layer, thereby increasing the combination of electrons and holes.

According to a specific embodiment of the present invention, preferably, in the above nitride semiconductor structure, the quaternary carrier active layer is doped with a P-type dopant with a concentration greater than 10 ¹⁸ cm ⁻³ . Wherein, more preferably, the P-type dopant may be, for example, magnesium.

According to a specific embodiment of the present invention, preferably, in the above nitride semiconductor structure, the thickness of the quaternary carrier active layer is 50-300 nm.

In addition, according to a specific embodiment of the present invention, preferably, in the above-mentioned nitride semiconductor structure, an N-type carrier blocking layer (such as N-type aluminum gallium nitride, etc.) may also be arranged between the light-emitting layer and the N-type semiconductor layer. ), and the N-type carrier blocking layer is made of a material with an energy gap larger than that of the light-emitting layer. Similarly, the N-type carrier blocking layer is made of a material with a higher energy gap than the light-emitting layer to avoid electrical Holes escape into the N-type semiconductor layer to increase the probability of electron-hole combination.

The present invention also provides a semiconductor light emitting element, which at least includes:

a substrate;

an N-type semiconductor layer configured on the substrate;

a light-emitting layer configured on the N-type semiconductor layer;

A quaternary carrier active layer, which is arranged on the light-emitting layer, the quaternary carrier active layer is aluminum indium gallium nitride Al _x In _y Ga _1-xy N, where x and y satisfy 0<x Values <1, 0<y<1, 0<x+y<1;

A P-type semiconductor layer configured on the quaternary carrier active layer;

an N-type electrode disposed on the N-type semiconductor layer in ohmic contact; and

A P-type electrode is configured on the P-type semiconductor layer by ohmic contact.

The semiconductor light-emitting element of the present invention includes the above-mentioned nitride semiconductor structure on a substrate, and two N-type electrodes and P-type electrodes that cooperate to provide electric energy; thus, the content of indium in the quaternary carrier active layer is controlled, so that four The energy gap of the meta-carrier active layer is higher than the energy gap of the barrier layer, which not only enhances the entry of holes into the multiple quantum well structure, but also achieves the effect of inhibiting electrons from escaping into the P-type semiconductor layer, increasing the probability of electrons and holes combining. It can also be used as a buffer layer between the P-type semiconductor layer and the light-emitting layer to improve the problem of crystal quality degradation caused by the lattice mismatch between the P-type semiconductor layer and the light-emitting layer; The main group element dopant can reduce the inactivation phenomenon caused by the Mg-H bond, activate the Mg and have the effective effect of the acceptor, and then make the quaternary carrier active layer have a high hole concentration and provide more electricity. Holes enter the light-emitting layer to increase the combination of electrons and holes, so that the semiconductor light-emitting element can exhibit a sufficiently low impedance, thereby obtaining better luminous efficiency.

Furthermore, according to a specific embodiment of the present invention, preferably, in the above-mentioned semiconductor light-emitting element, a buffer layer may also be formed on the surface between the substrate and the N-type semiconductor layer, and the buffer layer is aluminum gallium nitride Al _z Ga _{1 -z} N, where 0<z<1; to solve epitaxial dislocation caused by lattice difference.

Description of drawings

FIG. 1 is a schematic cross-sectional view of a nitride semiconductor structure provided by a preferred embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view of a semiconductor light-emitting element made of a nitride semiconductor structure according to a preferred embodiment of the present invention.

Description of main component symbols:

1 Substrate 2N-type semiconductor layer

21N type electrode 3P type semiconductor layer

31P type electrode 4 light-emitting layer

41 barrier layer 42 well layer

5 Quaternary carrier active layer 6N-type carrier blocking layer

7 buffer layers

Detailed ways

The purpose of the present invention and its structural design and functional advantages will be described according to the following drawings and preferred embodiments, so as to have a more in-depth and specific understanding of the present invention.

First, in the description of the following embodiments, it should be understood that when it is indicated that a layer (or film) or a structure is disposed "on" or "under" another substrate, another layer (or film), or another structure, It can be "directly" located on other substrates, layers (or films), or another structure, or can be configured "indirectly" with more than one intermediate layer between them. The location of each layer can be described with reference to the drawings.

Please refer to FIG. 1, which is a schematic cross-sectional view of a nitride semiconductor structure provided by a preferred embodiment of the present invention, which includes an N-type semiconductor layer 2 and a P-type semiconductor layer 3, between the N-type semiconductor layer 2 and the P-type semiconductor layer. A light-emitting layer 4 (active layer) is arranged between the P-type semiconductor layers 3, and a quaternary carrier active layer 5 is arranged between the light-emitting layer 4 and the P-type semiconductor layer 3, and the quaternary carrier active layer 5 is aluminum indium gallium nitride Al _x In _y Ga _1-xy N, wherein x and y are values satisfying 0<x<1, 0<y<1, 0<x+y<1; in addition, the above-mentioned quaternary carrier active layer 5 is doped Doped with a fourth main group element (preferably carbon) at a concentration of 10 ¹⁶ -10 ¹⁹ cm ^-3 ; in this embodiment, the N-type semiconductor layer 2 is an N-type gallium nitride-based semiconductor layer, and the P-type semiconductor layer 3 is a p-type gallium nitride-based semiconductor layer.

Furthermore, the above-mentioned quaternary carrier active layer 5 is doped with a P-type dopant (such as magnesium) with a concentration greater than 10 ¹⁸ cm ^-3 , and, preferably, the thickness of the quaternary carrier active layer 5 is 50 -300nm.

In addition, the above-mentioned light-emitting layer 4 has a multiple quantum well structure; wherein, the multiple quantum well structure can be formed by alternately stacking the well layer 42 of InGaN and the barrier layer 41 of GaN, and is adjacent to the multiple quantum well structure. The energy gap of the quaternary carrier active layer 5 of the last well layer 42 is greater than the energy gap of the barrier layer 41 of the multiple quantum well structure, wherein, preferably, the energy gap of the quaternary carrier active layer 5 is higher than that of the barrier layer The energy gap of 41 is 1%-15%. Therefore, compared with the known P-AlGaN electron blocking layer, it not only improves the effect of holes entering the multiple quantum well structure, but also suppresses the escape of electrons into the P-type semiconductor layer3 The purpose is to increase the combination probability of electrons and holes, and further improve the luminous efficiency; in addition, an N-type carrier blocking layer 6 can also be arranged between the light-emitting layer 4 and the N-type semiconductor layer 2, and the N-type carrier blocking layer 6 It is made of a material with a higher energy gap than the light-emitting layer 4; in this embodiment, it is N-type aluminum gallium nitride (N-AlGaN), so as to prevent holes from escaping into the N-type semiconductor layer 2 .

It is worth noting here that since the quaternary carrier active layer 5 formed of Al _x In _y Ga _1-xy N material is located between the P-type semiconductor layer 3 and the light-emitting layer 4, by controlling the quaternary carrier active layer The content of indium in 5 makes the indium content of the quaternary carrier active layer 5 equal to or lower than the indium content of the well layer 42 of the multiple quantum well structure, thereby forming an energy gap greater than the energy gap of the well barrier layer 41 by 1%-15 % of the quaternary carrier active layer 5, so that the carrier can be confined in the well layer 42 of the multiple quantum well structure, so as to increase the probability of electron hole recombination, thereby improving the internal quantum efficiency, and effectively enhancing the luminous efficiency of the semiconductor light-emitting element In addition, the quaternary carrier active layer 5 of the present invention can be used as a buffer layer between the P-type semiconductor layer 3 and the light-emitting layer 4 to improve the lattice mismatch caused by the P-type semiconductor layer 3 and the light-emitting layer 4. The problem of crystal quality deterioration; at the same time, it can reduce the impact of compressive stress on the well layer 42, so that the electrons and holes in the well layer 42 are more concentrated in space, effectively confining the electron holes to each well layer 42, to improve the internal quantum efficiency; in addition, the reduction of the compressive stress also enhances the interface characteristics between the adjacent GaN barrier layer 41 and the InGaN well layer 42, so as to improve the carrier loss at the interface and increase the internal quantum efficiency. efficiency.

When the nitride semiconductor structure of the above embodiment is actually implemented and used, since the energy gap of the quaternary carrier active layer 5 is 1%-15% higher than the energy gap of the barrier layer 41, not only the effect of suppressing the overflow of electrons can be achieved, It can also improve the effect of hole injection, increase the combination probability of electrons and holes, and further improve the luminous efficiency; in addition, since the quaternary carrier active layer 5 is doped with the fourth main body with a concentration of 10 ¹⁶ -10 ¹⁹ cm ^-3 Group elements, use the fourth main group element to replace the pentavalent nitrogen atom, so as to add a positively charged hole, so that the quaternary carrier active layer 5 can have a high hole concentration, the above-mentioned fourth main group element can be, for example Carbon (C), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), etc., wherein, preferably, the fourth main group element is carbon, the reason is: in the process of epitaxy , the carbon will react with the hydrogen decomposed from the ammonia gas and form a stable compound CH ₄ , which is separated from the nitride semiconductor, so the content of H is reduced, and the bonding of Mg-H is also reduced, causing Mg to have an ionic state, therefore, the quaternary carrier active layer 5 can have a high hole concentration, thereby providing more holes to enter the light-emitting layer 4, thereby increasing the combination of electrons and holes; it is noteworthy that if the fourth The doping concentration of the main group elements in the quaternary carrier active layer 5 is less than 10 ¹⁶ cm ^-3 , which cannot provide the effect of holes. If the doping concentration of the fourth main group elements is greater than 10 ¹⁹ cm ^-3 , resistance will be generated. If the value becomes high, the preferred doping concentration is 5×10 ¹⁶ -5×10 ¹⁸ cm ^-3 .

Please refer to FIG. 2, the above-mentioned nitride semiconductor structure can be applied to semiconductor light-emitting elements. FIG. 2 is a schematic cross-sectional view of a semiconductor light-emitting element made of a nitride semiconductor structure according to a preferred embodiment of the present invention. Light emitting elements include at least:

a substrate 1;

An N-type semiconductor layer 2 configured on the substrate 1;

A light-emitting layer 4, which is arranged on the N-type semiconductor layer 2; wherein, the light-emitting layer 4 has a multiple quantum well structure, and the multiple quantum well structure can be alternated by well layers 42 of indium gallium nitride and barrier layers 41 of gallium nitride formed by a stack, and has a well layer 42 between every two barrier layers 41;

A quaternary carrier active layer 5, which is arranged on the light-emitting layer 4, the quaternary carrier active layer 5 is aluminum indium gallium nitride Al _x In _y Ga _1-xy N, wherein x and y satisfy 0<x< 1. Values of 0<y<1, 0<x+y<1, preferably 0<x≤0.4, 0<y≤0.2; moreover, the quaternary carrier active layer 5 is doped with a concentration of 10 ¹⁶ -10 ¹⁹ cm ^-3 of the fourth main group element (preferably carbon); wherein, preferably, the thickness of the quaternary carrier active layer 5 is 50-300nm, and can be doped with a concentration greater than 10 ¹⁸ cm ^-3 P-type dopant (such as magnesium), and the energy gap of the quaternary carrier active layer 5 is greater than the energy gap of the barrier layer 41 of the multiple quantum well structure, preferably 1%-15% higher than the energy gap of the barrier layer 41 %;

A P-type semiconductor layer 3 configured on the quaternary carrier active layer 5;

An N-type electrode 21, which is configured on the N-type semiconductor layer 2 with an ohmic contact; and

A P-type electrode 31, which is configured on the P-type semiconductor layer 3 with ohmic contact; wherein, the N-type electrode 21 and the P-type electrode 31 cooperate to provide electric energy, and can be made of the following materials, but not limited to these materials: Titanium, aluminum, gold, chromium, nickel, platinum and their alloys, etc., and their processing methods are well known to those skilled in the art, and are not the focus of the present invention, so they will not be repeated in the present invention.

In addition, an N-type carrier blocking layer 6 can be further arranged between the light-emitting layer 4 and the N-type semiconductor layer 2, and the N-type carrier blocking layer 6 is made of a material having an energy gap higher than that of the light-emitting layer 4; Or, in order to solve the epitaxial dislocation phenomenon caused by the lattice difference, a buffer layer 7 can also be formed between the substrate 1 and the N-type semiconductor layer 2, and the buffer layer 7 is aluminum gallium nitride Al _z Ga _1-z N , where 0<z<1.

It can be seen from the above description of the implementation of the nitride semiconductor structure that the semiconductor light-emitting element of the present invention controls the content of indium in the quaternary carrier active layer 5 so that the energy gap of the quaternary carrier active layer 5 is higher than that of the barrier layer 41. The energy gap is 1%-15%, which can not only improve the entry of holes into the multiple quantum well structure, but also achieve the effect of inhibiting electrons from escaping into the P-type semiconductor layer 3, so that the combination probability of electrons and holes increases, and can be used as a P-type semiconductor layer 3 and the buffer layer 7 between the light emitting layer 4 to improve the crystal quality deterioration caused by the lattice mismatch between the P-type semiconductor layer 3 and the light emitting layer 4; in addition, the fourth main group of the quaternary carrier active layer 5 The element dopant can reduce the inactivation phenomenon caused by the Mg-H bond, activate the Mg and have the effective effect of the acceptor, and then make the quaternary carrier active layer 5 have a high hole concentration and provide more holes Entering the light-emitting layer 4, the combination of electrons and holes is increased, so that the semiconductor light-emitting element can exhibit a sufficiently low impedance, thereby obtaining better luminous efficiency.

Claims (10)

1. A kind of 1. nitride semiconductor structure, it is characterised in that including：

   One p type semiconductor layer；

   One n type semiconductor layer；

   One luminescent layer, between the p type semiconductor layer and the n type semiconductor layer；And

   The gallium nitride carrier active layer of one p-type, between the p type semiconductor layer and the luminescent layer, the p-type gallium nitride Be carrier active layer material include aluminium and indium at least one, and the gallium nitride carrier active layer of the p-type doped with carbon and Magnesium, wherein the doping concentration of the carbon is 5 × 10¹⁶~5 × 10¹⁸cm^-3。
2. 2. nitride semiconductor structure as claimed in claim 1, it is characterised in that the doping concentration of the magnesium admixture is more than 10¹⁸cm^-3。
3. 3. nitride semiconductor structure as claimed in claim 1, it is characterised in that also including a carrier barrier layer, positioned at institute State between n type semiconductor layer and the luminescent layer.
4. 4. nitride semiconductor structure as claimed in claim 3, it is characterised in that the energy gap of the carrier barrier layer is higher than institute State the energy gap of luminescent layer.
5. 5. nitride semiconductor structure as claimed in claim 3, it is characterised in that the material of the carrier barrier layer includes N Type aluminium gallium nitride alloy.
6. 6. nitride semiconductor structure as claimed in claim 1, it is characterised in that the luminescent layer has multiple quantum trap knot Structure, the multiple quantum well construction include the well layer and barrier layer of a plurality of stackings alternating with each other, the gallium nitride carrier of p-type Active layer is in close proximity to the multiple quantum well construction, and the energy gap of the gallium nitride carrier active layer of the p-type is more than the barrier The energy gap of layer.
7. 7. nitride semiconductor structure as claimed in claim 6, it is characterised in that also including a carrier barrier layer, the load Sub- barrier layer is between the n type semiconductor layer and the luminescent layer, wherein the material of the carrier barrier layer includes N-type nitrogen Change gallium aluminium.
8. A kind of 8. nitride semiconductor structure, it is characterised in that including：

   One p type semiconductor layer, include a carbon enrichment layer, wherein the carbon enrichment layer material include Al-In-Ga-N and doped with Magnesium admixture and carbon admixture；

   One n type semiconductor layer；And

   One luminescent layer, between the p type semiconductor layer and the n type semiconductor layer, and the carbon enrichment layer position is in the P The side for being adjacent to the luminescent layer of type semiconductor layer.
9. 9. nitride semiconductor structure as claimed in claim 8, it is characterised in that the luminescent layer has multiple quantum trap knot Structure, the multiple quantum well construction include the well layer and barrier layer of a plurality of stackings alternating with each other, and the carbon enrichment layer is in close proximity to The multiple quantum well construction, and the energy gap of the carbon enrichment layer is more than the energy gap of the barrier layer.
10. 10. nitride semiconductor structure as claimed in claim 9, it is characterised in that the energy gap of the carbon enrichment layer is more than institute State the energy gap 1%~15% of barrier layer.