CN220456444U

CN220456444U - Semiconductor structure

Info

Publication number: CN220456444U
Application number: CN202223357941.XU
Authority: CN
Inventors: 刘慰华
Original assignee: Wuxi Jingzhan Semiconductor Co ltd
Current assignee: Wuxi Jingzhan Semiconductor Co ltd
Priority date: 2022-12-13
Filing date: 2022-12-13
Publication date: 2024-02-06
Anticipated expiration: 2032-12-13

Abstract

The utility model provides a semiconductor structure, which comprises a first semiconductor layer, a multi-quantum well layer, an inserting layer and a second semiconductor layer, wherein the multi-quantum well layer is arranged on the first semiconductor layer and comprises quantum barrier layers and quantum well layers which are alternately arranged, the inserting layer is arranged on the quantum well layer, and the second semiconductor layer is arranged on the multi-quantum well layer, and the inserting layer is B _x Al _y Ga _z N material, x+y+z=1. In the utility model, the BAlGaN insertion layer can enlarge the energy gap difference between the quantum well layer and the quantum barrier layer, thereby improving the probability of capturing carriers and forming radiation recombination by the quantum well layer and improving the deep purpleThe luminous efficiency of the outer LED.

Description

Semiconductor structure

Technical Field

The utility model relates to the technical field of semiconductors, in particular to a semiconductor structure.

Background

Group iii nitrides, which are excellent representatives of wide bandgap semiconductor materials, have achieved high efficiency solid-state light source devices such as blue-green Light Emitting Diodes (LEDs), lasers, etc., which have achieved great success in applications such as flat panel displays, white light illumination, etc. In the last decade, it has been desired to apply such highly efficient luminescent materials to the ultraviolet band to meet the increasing demands of ultraviolet light sources. The prior researches show that AlGaN in the III-group nitride is the best candidate material for preparing the semiconductor ultraviolet light source device, and the AlGaN-based ultraviolet LED has the advantages of no toxicity, environmental protection, small size, portability, low power consumption, low voltage, easy integration, long service life, adjustable wavelength and the like, is expected to be breakthrough developed and widely applied in the next few years, and gradually replaces the traditional ultraviolet mercury lamp.

The current AlGaN-based ultraviolet LED device has low luminous efficiency compared with a GaN-based blue LED, and particularly in a deep ultraviolet band, the external quantum efficiency of the device is often lower than 10%. The main reasons for this phenomenon include lower internal quantum efficiency of AlGaN-based uv LEDs, higher material defect density in AlGaN materials, and so on. The low internal quantum efficiency is mainly related to the low electron capturing efficiency and the low hole injection efficiency in the ultraviolet LED active region, so that electrons can easily escape from the constraint of the quantum well and leak to the p-type region to be subjected to non-radiative recombination with holes.

Disclosure of Invention

In view of the above, the embodiment of the utility model provides a semiconductor structure to solve the technical problem of low internal quantum efficiency of an AlGaN-based deep ultraviolet LED in the prior art.

According to one aspect of the present utility model, a semiconductor structure is provided, comprising

A first semiconductor layer;

a multiple quantum well layer formed on the first semiconductor layer, the multiple quantum well layer including quantum barrier layers and quantum well layers alternately arranged;

an insertion layer formed on the quantum well layer;

a second semiconductor layer formed on the multiple quantum well layer;

wherein the insertion layer is B _x Al _y Ga _z N material, x+y+z=1.

As an alternative embodiment, the insertion layer B component x is 0.01 or more and 0.2 or less, and the insertion layer Ga component z is 0.45 or less.

As an alternative embodiment, the thickness of each of the insertion layers is 1nm or more and 10nm or less.

As an alternative embodiment, the insertion layer may be n-doped or p-doped.

As an alternative embodiment, the B-component of each of the insertion layers varies as a combination of one or more of a uniform constant, a linear increase, a linear decrease, a stepwise increase, a stepwise decrease, a delta change in a direction away from the first semiconductor layer.

As an alternative embodiment, a plurality of the insertion layer B components x are uniformly increased or increased in a jump manner layer by layer in a direction away from the first semiconductor layer.

As an alternative embodiment, the semiconductor structure further comprises an insertion layer on the quantum barrier layer, the insertion layer being B _x Al _y Ga _z N material, x+y+z=1.

As an alternative embodiment, the interposer is a multilayer structure in a direction away from the first semiconductor layer.

As an alternative embodiment, the multilayer structure comprises a first boron component layer and a second boron component layer remote from the quantum well layer, which are arranged in a stack.

As an alternative embodiment, the B-component x of the first boron component layer is greater than the B-component x of the second boron component layer.

As an alternative embodiment, the multilayer structure is a superlattice structure.

As an alternative embodiment, the superlattice structure is composed of a high B-component BAlGaN/low B-component BAlGaN periodic structure.

As an alternative embodiment, the interposer layer has a plurality of sub-regions in the horizontal direction.

As an alternative embodiment, the B-component x of at least two sub-regions of the plurality of sub-regions is different.

As an alternative embodiment, the quantum well layer and the quantum barrier layer are AlGaN materials.

As an alternative embodiment, the first semiconductor layer is an n-type layer, the second semiconductor layer is a p-type layer, the first semiconductor layer and the second semiconductor layer are AlGaN materials.

Compared with the prior art, the utility model has the beneficial effects that:

the utility model provides a semiconductor structure, which comprises a first semiconductor layer, a multi-quantum well layer, an inserting layer and a second semiconductor layer, wherein the multi-quantum well layer is arranged on the first semiconductor layer and comprises quantum barrier layers and quantum well layers which are alternately arranged, the inserting layer is arranged on the quantum well layer, and the second semiconductor layer is arranged on the multi-quantum well layer, and the inserting layer is B _x Al _y Ga _z N material, x+y+z=1. In the utility model, the BAlGaN insertion layer can enlarge the energy gap difference between the quantum well layer and the quantum barrier layer, thereby improving the probability of capturing carriers and forming radiation recombination by the quantum well layer; meanwhile, due to the introduction of the B element, the lattice constant of the BAlGaN is larger than that of AlGaN, and the band bending of a conduction band and a valence band caused by built-in stress formed at the interface of the BAlGaN insertion layer and the AlGaN quantum well layer is larger, so that the radiation recombination probability of carriers under the forward bias condition is further improved, and the luminous efficiency of the deep ultraviolet LED is further improved.

Drawings

Fig. 1 is a schematic view of a semiconductor structure according to a first embodiment of the present utility model.

Fig. 2 is a schematic diagram of a semiconductor structure according to a second embodiment of the present utility model.

Fig. 3a and 3B are schematic views showing two variations of the composition of the semiconductor structure insertion layer B according to the third embodiment of the present utility model, respectively.

Fig. 4 is a schematic view of a semiconductor structure according to a fourth embodiment of the present utility model.

Fig. 5 is a schematic view of a semiconductor structure according to a fifth embodiment of the present utility model.

Fig. 6 is a schematic view of a semiconductor structure according to a sixth embodiment of the present utility model.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In order to solve the technical problem of low quantum efficiency in AlGaN-based deep ultraviolet LEDs in the prior art, the utility model provides a semiconductor structure, which comprises a first semiconductor layer, a multiple quantum well layer, an inserting layer and a second semiconductor layer, wherein the multiple quantum well layer is arranged on the first semiconductor layer and comprises quantum barrier layers and quantum well layers which are alternately arranged, the inserting layer is arranged on the quantum well layer, and the second semiconductor layer is arranged on the multiple quantum well layer, and the inserting layer is B _x Al _y Ga _z N material, x+y+z=1. In the utility model, the BAlGaN insertion layer can enlarge the energy gap difference between the quantum well layer and the quantum barrier layer, thereby improving the probability of capturing carriers and forming radiation recombination by the quantum well layer; meanwhile, due to the introduction of the B element, the lattice constant of the BAlGaN is larger than that of AlGaN, and the band bending of a conduction band and a valence band caused by built-in stress formed at the interface of the BAlGaN insertion layer and the AlGaN quantum well layer is larger, so that the radiation recombination probability of carriers under the forward bias condition is further improved, and the luminous efficiency of the deep ultraviolet LED is further improved.

The semiconductor structure referred to in the present utility model is further illustrated in the following in connection with fig. 1 to 6.

As shown in fig. 1, the semiconductor structure includes a first semiconductor layer 10, a multiple quantum well layer 20 formed on the first semiconductor layer 10, the multiple quantum well layer 20 including quantum barrier layers 21 and quantum well layers 22 alternately arranged, an insertion layer 23 formed on the quantum well layers 22, and a second semiconductor layer 30 formed on the multiple quantum well layer 20. The insertion layer 23 is B _x Al _y Ga _z N material, x+y+z=1.

In this embodiment, the semiconductor structure further comprises a substrate 1. The material of the substrate 1 comprises Si, al ₂ O ₃ Any one or a combination of a plurality of GaN, siC or AlN. In order to relieve stress in the epitaxial structure above the substrate, avoid cracking of the epitaxial structure,the semiconductor structure may further comprise a buffer layer 2 prepared above the substrate 1, the buffer layer 2 may include one or more of AlN, gaN, alGaN, alInGaN, but is not limited thereto.

In this embodiment, the first semiconductor layer 10 and the second semiconductor layer 30 are AlGaN materials. The first semiconductor layer 10 is an n-type layer, and the n-type doping ions may be at least one of Si ions, ge ions, sn ions, se ions, or Te ions. The second semiconductor layer 30 is a p-type layer, and the p-type doping ions may be at least one of Mg ions, zn ions, ca ions, sr ions, or Ba ions. The first semiconductor layer 10 and the second semiconductor layer 30 may be grown in situ, or may be formed by atomic layer deposition (ALD, atomic layer deposition), or chemical vapor deposition (CVD, chemical Vapor Deposition), or molecular beam epitaxy (MBE, molecular Beam Epitaxy), or plasma enhanced chemical vapor deposition (PECVD, plasma Enhanced Chemical Vapor Deposition), or low pressure chemical vapor deposition (LPCVD, low Pressure Chemical Vapor Deposition), or Metal-organic chemical vapor deposition (MOCVD, metal-Organic Chemical Vapor Deposition), or a combination thereof.

In this embodiment, the forbidden bandwidth of the quantum barrier layer 21 is larger than that of the quantum well layer 22. For example, the material of the quantum barrier layer 21 is Al with an Al component a of between 0.55 and 0.65 _a Ga _1-a N, the material of the quantum well layer 22 is Al with Al component a between 0.40 and 0.45 _a Ga _1-a N。

In this embodiment, the composition x of the insertion layers 23B is 0.01 or more and 0.2 or less, the composition z of ga is 0.45 or less, and the composition B of each insertion layer 23 changes uniformly, linearly, stepwise, or delta in a direction away from the first semiconductor layer 10. The Delta variation growth method is to switch off a III family source (such as a gallium source and an aluminum source) and simultaneously switch on a boron source, so that boron atoms present a Delta function-like distribution inside the material. The method for growing the epitaxial layer by modulating the energy band through doping in a limited area of the epitaxial layer can reduce the ionization energy.

In this embodiment, the insertion layer 23 may be n-type doped or p-type doped. When the insertion layer 23 is n-doped, for example doped with silicon or germanium, it is advantageous to reduce the electrical barrier formed by the higher conduction band bottom introduced by the insertion layer 23, thereby increasing the longitudinal conductivity and reducing the forward operating voltage of the LED. When the insertion layer 23 is doped with p-type, for example, magnesium or zinc is doped, the number of holes can be effectively increased, which is beneficial to improving the internal quantum efficiency of the light emitting diode and finally improving the light emitting efficiency of the light emitting diode.

In this embodiment, the thickness of the insertion layer 23 is 1nm or more and 10nm or less. In order to introduce built-in stress on the quantum well layer 22, a BAlGaN insertion layer 23 is grown beyond a critical thickness.

In this embodiment, when the insertion layer 23 is made of BAlGaN material, the energy gap difference between the quantum well layer 22 and the quantum barrier layer 21 can be increased, so as to improve the probability of capturing carriers and forming radiation recombination by the quantum well layer 22; meanwhile, due to the introduction of the B element, the lattice constant of the BAlGaN is larger than that of AlGaN, and the band bending of a conduction band and a valence band caused by built-in stress formed at the interface of the BAlGaN insertion layer 23 and the AlGaN quantum well layer 22 is larger, so that the radiation recombination probability of carriers under the forward bias condition is further improved, and the luminous efficiency of the deep ultraviolet LED is further improved.

Preferably, the semiconductor structure provided in this embodiment may be introduced with an indium source during the epitaxial growth process, so that the entire semiconductor structure contains a trace amount of indium, and plays a role in stress modulation, thereby improving the light emitting uniformity of the multiple quantum well layer 20 and improving the light emitting efficiency of the light emitting device.

Referring to fig. 2, the semiconductor structure of the second embodiment is different from the semiconductor structure of the first embodiment in that: the semiconductor structure further comprises an interposer 230 on the quantum barrier layer 21, the interposer 230 being B _x Al _y Ga _z N material, x+y+z=1. The insertion layer 230 can further increase the energy gap difference between the quantum well layer 22 and the quantum barrier layer 21, further improve the capture of carriers by the quantum well layer 20 and form radiationProbability of shoot recombination.

In addition to the above differences, the other structures of the semiconductor structure of the second embodiment can refer to the corresponding structures of the semiconductor structure of the first embodiment.

Fig. 3a and 3B are schematic diagrams showing two variations of the component x of the semiconductor structure insertion layer B according to the third embodiment of the present utility model, respectively.

Referring to fig. 3, the semiconductor structure of the third embodiment is different from the semiconductor structures of the first and second embodiments in that: the composition x of the plurality of intervening layers 23a,23B, … B is either uniformly increasing layer by layer (fig. 3 a) or increasing in transitions (fig. 3B) in a direction away from the first semiconductor layer 10. The composition x of the plurality of insertion layers 23a,23B, … B is gradually increased to improve the film quality of the subsequently grown insertion layers, and the surface morphology of the material can be changed to improve the optical quality, thereby improving the luminous efficiency of the LED.

In addition to the above differences, the other structures of the semiconductor structure of the third embodiment can refer to the corresponding structures of the semiconductor structures of the first and second embodiments.

Referring to fig. 4, the semiconductor structure of the fourth embodiment is different from the semiconductor structures of the first, second and third embodiments in that: in a direction away from the first semiconductor layer 10, the interposer 23 has a multilayer structure including: a first boron component layer 231 disposed in a stacked manner and remote from a second boron composition layer 232 of the quantum well layer 22. The B-component x of the first boron component layer 231 is greater than the B-component x of the second boron component layer 232. The B component x of the first boron component layer 231 is larger, the band bending of the conduction band and the valence band caused by the built-in stress formed at the interface of the BAlGaN insertion layer 23 and the AlGaN quantum well layer 22 is larger, and the radiation recombination probability of carriers under the forward bias condition is improved, so that the luminous efficiency of the deep ultraviolet LED is improved. The B-component x of the second boron component layer 232 away from the quantum well layer 22 is reduced, the lattice constant gap from the quantum barrier layer 21 thereabove is reduced, and the crystal growth quality of the quantum barrier layer 21 thereabove is ensured.

In addition to the above differences, the other structures of the semiconductor structure of the fourth embodiment can refer to the corresponding structures of the semiconductor structures of the first, second and third embodiments.

Referring to fig. 5, the semiconductor structure of the fifth embodiment differs from the semiconductor structures of the first to fourth embodiments in that: in a direction away from the first semiconductor layer 10, the insertion layer 23 has a multi-layered structure, for example, a superlattice structure, and is composed of a periodic structure of a high-B-component BAlGaN insertion layer 233 and a low-B-component BAlGaN insertion layer 234. The multi-layer insert layer structure can avoid the cracking effect possibly caused by temperature change when the whole epitaxial layer grows under the high temperature condition, and the crystal quality is not reduced when the built-in stress is introduced to the AlGaN quantum well layer 22.

In addition to the above differences, other structures of the semiconductor structure of the fifth embodiment may refer to corresponding structures of the semiconductor structures of the first, second, third and fourth embodiments.

Referring to fig. 6, the semiconductor structure of the sixth embodiment differs from the semiconductor structures of the first to fifth embodiments in that: in the horizontal direction, the insertion layer 23 has a plurality of sub-regions S1, …, sm, of which at least two are different in B-component x. By adjusting the B component x in the horizontal direction of the insertion layer 23, the stress distribution of the whole multi-quantum well layer 20 can be adjusted, the uniformity of the spatial distribution of electrons and holes in the multi-quantum well active region can be improved, and the radiation recombination efficiency of electrons and holes in the active region can be improved, so that the light emitting uniformity of the multi-quantum well layer 20 and the light emitting efficiency of the deep ultraviolet LED can be improved.

In addition to the above differences, other structures of the semiconductor structure of the sixth embodiment can refer to corresponding structures of the semiconductor structures of the first, second, third, fourth and fifth embodiments.

The utility model provides a semiconductor structure, which comprises a first semiconductor layer, a multiple quantum well layer, an insertion layer and a multiple quantum well layer, wherein the multiple quantum well layer comprises a quantum barrier layer and a quantum well layer which are alternately arranged on the first semiconductor layer, the insertion layer is arranged on the quantum well layer, and the multiple quantum well layer is arranged on the first semiconductor layerA second semiconductor layer thereon, wherein the insertion layer is B _x Al _y Ga _z N material, x+y+z=1. In the utility model, the BAlGaN insertion layer can enlarge the energy gap difference between the quantum well layer and the quantum barrier layer, thereby improving the probability of capturing carriers and forming radiation recombination by the quantum well layer; meanwhile, due to the introduction of the B element, the lattice constant of the BAlGaN is larger than that of AlGaN, and the band bending of a conduction band and a valence band caused by built-in stress formed at the interface of the BAlGaN insertion layer and the AlGaN quantum well layer is larger, so that the radiation recombination probability of carriers under the forward bias condition is further improved, and the luminous efficiency of the deep ultraviolet LED is further improved.

It should be understood that the term "include" and variations thereof as used herein is intended to be open-ended, i.e., including, but not limited to. The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment". In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is to be construed as including any modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims

1. A semiconductor structure, comprising:

a first semiconductor layer (10);

a multiple quantum well layer (20) formed on the first semiconductor layer (10), the multiple quantum well layer (20) including quantum barrier layers (21) and quantum well layers (22) alternately arranged;

an insertion layer (23) formed on the quantum well layer (22);

a second semiconductor layer (30) formed on the multiple quantum well layer (20);

wherein the insertion layer (23) is B _x Al _y Ga _z N material, x+y+z=1.

2. A semiconductor structure according to claim 1, wherein the thickness of each of the insertion layers (23) is 1nm or more and 10nm or less.

3. A semiconductor structure according to claim 1, characterized in that the insertion layer (23) may be n-doped or p-doped.

4. The semiconductor structure of claim 1, wherein the B-composition of each of the insertion layers (23) varies as a combination of one or more of a uniform constant, a linear increase, a linear decrease, a stepwise increase, a stepwise decrease, a delta change, in a direction away from the first semiconductor layer (10).

5. The semiconductor structure of claim 1, wherein a plurality of the interposer (23 a,23B, …) B components x are uniformly or incrementally stepped from layer to layer in a direction away from the first semiconductor layer (10).

6. The semiconductor structure of claim 1, wherein, the semiconductor structure further comprises an insertion layer (230) on the quantum barrier layer (21), the insertion layer (230) being B _x Al _y Ga _z N material, x+y+z=1.

7. The semiconductor structure according to claim 1, characterized in that the interposer (23) is a multilayer structure in a direction away from the first semiconductor layer (10).

8. The semiconductor structure of claim 7, characterized in that the multilayer structure comprises a first boron component layer (231) and a second boron component layer (232) remote from the quantum well layer (22) arranged in a stack.

9. The semiconductor structure of claim 8, wherein a B-component x of said first boron component layer (231) is greater than a B-component x of said second boron component layer (232).

10. The semiconductor structure of claim 7, wherein the multi-layer structure is a superlattice structure.

11. The semiconductor structure according to claim 1, characterized in that the interposer (23) has a plurality of sub-regions (S1, …, sm) in the horizontal direction.

12. The semiconductor structure of claim 1, wherein the quantum well layer (22) and the quantum barrier layer (21) are AlGaN materials.

13. The semiconductor structure of claim 1, wherein the first semiconductor layer (10) is an n-type layer, the second semiconductor layer (30) is a p-type layer, and the first semiconductor layer (10) and the second semiconductor layer (30) are AlGaN materials.