WO2018052252A1

WO2018052252A1 - Semiconductor device and semiconductor device package including same

Info

Publication number: WO2018052252A1
Application number: PCT/KR2017/010065
Authority: WO
Inventors: 최낙준; 김병조; 오현지
Original assignee: 엘지이노텍 주식회사
Priority date: 2016-09-13
Filing date: 2017-09-13
Publication date: 2018-03-22

Abstract

One embodiment discloses a semiconductor device and a semiconductor device package including the same, the semiconductor device comprising: a light-emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer arranged between the first conductive semiconductor layer and the second conductive semiconductor layer; a first electrode electrically connected with the first conductive semiconductor layer; and a second electrode electrically connected with the second conductive semiconductor layer, wherein the second conductive semiconductor layer includes a first surface on which the second electrode is arranged and has a ratio (W2:W1) between a second minimum distance (W2) from the first surface to a second point and a first minimum distance (W1) from the first surface to a first point of 1:1.25 to 1:100, respectively, the first point is a point having the same composition as an aluminum composition of a well layer closest to the second conductive semiconductor layer in the active layer, and the second point is the point at which the aluminum composition and a dopant composition of the second conductive semiconductor layer become equal.

Description

Semiconductor device and semiconductor device package including same

An embodiment relates to a semiconductor device and a semiconductor device package including the same.

A semiconductor device including a compound such as GaN, AlGaN, etc. has many advantages, such as having a wide and easy-to-adjust band gap energy, and can be used in various ways as a light emitting device, a light receiving device, and various diodes.

Particularly, light emitting devices such as light emitting diodes and laser diodes using semiconductors of Group 3-5 or Group 2-6 compound semiconductors have been developed through the development of thin film growth technology and device materials. Various colors such as blue and ultraviolet light can be realized, and efficient white light can be realized by using fluorescent materials or combining colors.Low power consumption, semi-permanent lifespan, and fast response speed compared to conventional light sources such as fluorescent and incandescent lamps can be realized. It has the advantages of safety, environmental friendliness.

In addition, when a light-receiving device such as a photodetector or a solar cell is also manufactured using a group 3-5 or 2-6 compound semiconductor material of a semiconductor, the development of device materials absorbs light in various wavelength ranges to generate a photocurrent. As a result, light in various wavelengths can be used from gamma rays to radio wavelengths. It also has the advantages of fast response speed, safety, environmental friendliness and easy control of device materials, making it easy to use in power control or microwave circuits or communication modules.

Therefore, the semiconductor device may replace a light emitting diode backlight, a fluorescent lamp, or an incandescent bulb, which replaces a cold cathode tube (CCFL) constituting a backlight module of an optical communication means, a backlight of a liquid crystal display (LCD) display device. Applications are expanding to include white LED lighting devices, automotive headlights and traffic lights, and sensors that detect gas or fire. In addition, the semiconductor device may be extended to high frequency application circuits, other power control devices, and communication modules.

In particular, the light emitting device that emits light in the ultraviolet wavelength region may be used for curing, medical treatment, and sterilization by curing or sterilizing.

Recently, the research on the ultraviolet light emitting device is active, but the ultraviolet light emitting device has a problem that it is difficult to implement a vertical type, and there is a problem that the crystallinity is degraded in the process of separating the substrate.

The embodiment provides a vertical ultraviolet light emitting device.

In addition, a light emitting device having improved light output is provided.

The problem to be solved in the examples is not limited thereto, and the object or effect that can be grasped from the solution means or the embodiment described below will also be included.

A semiconductor device according to an embodiment of the present invention includes a light emitting device including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer. structure; A first electrode electrically connected to the first conductive semiconductor layer; And a second electrode electrically connected to the second conductive semiconductor layer, wherein the second conductive semiconductor layer includes a first surface on which the second electrode is disposed, and the second conductive semiconductor layer includes: The ratio W2: W1 of the second shortest distance W2 from the first surface to the second point and the first shortest distance W1 from the first surface to the first point is 1: 1.25 to 1: 100. The first point is a point having the same composition as the aluminum composition of the well layer closest to the second conductivity-type semiconductor layer among the active layer, the second point is the aluminum composition and the dopant composition of the second conductivity-type semiconductor layer It may be the point of equality.

According to the embodiment it is possible to manufacture a vertical ultraviolet light emitting device.

In addition, the light output can be improved.

Various and advantageous advantages and effects of the present invention are not limited to the above description, and will be more readily understood in the course of describing specific embodiments of the present invention.

1 is a conceptual diagram of a light emitting structure according to an embodiment of the present invention;

2 is a graph showing the aluminum composition ratio of the light emitting structure according to an embodiment of the present invention,

3 is a SIMS graph of the light emitting structure according to the first embodiment of the present invention.

4 is an enlarged view of a part of FIG. 3;

5 is a sims (SIMS) graph of the light emitting structure according to the second embodiment of the present invention,

6 is an enlarged view of a part of FIG. 5;

7 is a SIMS graph of a light emitting structure according to a third embodiment of the present invention,

8 is an enlarged view of a part of FIG. 7;

9 is a conceptual diagram of a semiconductor structure according to an embodiment of the present disclosure;

10 is a graph showing the aluminum composition ratio of the semiconductor structure according to an embodiment of the present invention,

11A and 11B illustrate SIMS data of a semiconductor structure according to an embodiment of the present disclosure.

11C and 11D are SIMS data of a semiconductor structure according to another embodiment of the present invention.

12 is a view showing the aluminum ion strength of FIGS. 11A-11D,

FIG. 13A is an enlarged view of a portion of the SIMS data of FIG. 12A;

FIG. 13B is a view of converting the SIMS data of FIG. 12B into a linear scale,

14A is a conceptual diagram of a second conductivity-type semiconductor layer according to an embodiment of the present invention;

14B is AFM data of a surface of a second conductivity-type semiconductor layer according to an embodiment of the present invention.

14C is AFM data of a surface of a GaN thin film,

14D is AFM data obtained by measuring the surface of the second conductivity type semiconductor layer grown at high speed,

15 is a conceptual diagram of a semiconductor device according to an embodiment of the present disclosure;

16A and 16B are views for explaining a configuration in which light output is improved according to a change in the number of recesses.

17 is an enlarged view of a portion A of FIG. 15;

18 is a conceptual diagram of a semiconductor device according to another embodiment of the present disclosure;

19 is a plan view of FIG. 18,

20 is a conceptual diagram of a semiconductor device package according to an embodiment of the present disclosure;

21 is a plan view of a semiconductor device package according to an embodiment of the present disclosure;

22 is a modification of FIG. 21,

23 is a cross-sectional view of a semiconductor device package according to another embodiment of the present disclosure;

24 is a conceptual diagram of a light emitting structure according to an embodiment of the present invention;

25 is a graph showing an aluminum composition of a light emitting structure according to an embodiment of the present invention;

26 is a graph showing an aluminum composition of a light emitting structure according to another embodiment of the present invention;

27 is a graph measuring light efficiency of a semiconductor device including a conventional light emitting structure,

28 is a graph measuring light efficiency of a light emitting structure according to another embodiment of the present invention;

29 is a graph showing an aluminum composition of a light emitting structure according to another embodiment of the present invention;

30 is a conceptual diagram of a light emitting structure grown on a substrate;

31 is a view for explaining a process of separating a substrate,

32 is a view for explaining a process of etching a light emitting structure;

33 is a view illustrating a manufactured semiconductor device.

The embodiments may be modified in other forms or in various embodiments, and the scope of the present invention is not limited to the embodiments described below.

Although matters described in a specific embodiment are not described in other embodiments, it may be understood as descriptions related to other embodiments unless there is a description that is contrary to or contradictory to the matters in other embodiments.

For example, if a feature is described for component A in a particular embodiment and a feature for component B in another embodiment, a description that is contrary or contradictory, even if the embodiments in which configuration A and configuration B are combined are not explicitly described. Unless otherwise, it should be understood to fall within the scope of the present invention.

In the description of the embodiment, when one element is described as being formed "on or under" of another element, it is on (up) or down (on). or under) includes both two elements being directly contacted with each other or one or more other elements are formed indirectly between the two elements. In addition, when expressed as "on" or "under", it may include the meaning of the downward direction as well as the upward direction based on one element.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

The light emitting structure according to the embodiment of the present invention may output light in the ultraviolet wavelength band. For example, the light emitting structure may output light in the near ultraviolet wavelength range (UV-A), may output light in the far ultraviolet wavelength range (UV-B), and emit light in the deep ultraviolet wavelength range (UV-C). You can print The wavelength range may be determined by the composition ratio of Al of the light emitting structure 120.

For example, the light (UV-A) in the near ultraviolet wavelength band may have a wavelength in the range of 320 nm to 420 nm, the light in the far ultraviolet wavelength band (UV-B) may have a wavelength in the range of 280 nm to 320 nm, and deep ultraviolet light Light in the wavelength band (UV-C) may have a wavelength in the range of 100nm to 280nm.

1 is a conceptual diagram of a light emitting structure according to an embodiment of the present invention, Figure 2 is a graph showing the aluminum composition ratio of the light emitting structure according to an embodiment of the present invention.

Referring to FIG. 1, a semiconductor device according to an embodiment may include a first conductive semiconductor layer 124, a second conductive semiconductor layer 127, and a first conductive semiconductor layer 124 and a second conductive semiconductor layer. It includes a light emitting structure 120 including an active layer 126 disposed between the (127).

The first conductive semiconductor layer 124 may be formed of a compound semiconductor such as a III-V group or a II-VI group, and may be doped with a first dopant. The first conductive semiconductor layer 124 is a semiconductor material having a composition formula of Inx1Aly1Ga1-x1-y1N (0 ≦ x1 ≦ 1, 0 ≦ y1 ≦ 1, 0 ≦ x1 + y1 ≦ 1), for example, GaN, AlGaN, InGaN, InAlGaN and the like can be selected. The first dopant may be an n-type dopant such as Si, Ge, Sn, Se, or Te. When the first dopant is an n-type dopant, the first conductive semiconductor layer 124 doped with the first dopant may be an n-type semiconductor layer.

The active layer 126 is disposed between the first conductive semiconductor layer 124 and the second conductive semiconductor layer 127. The active layer 126 is a layer where electrons (or holes) injected through the first conductive semiconductor layer 124 meet holes (or electrons) injected through the second conductive semiconductor layer 127. The active layer 126 transitions to a low energy level as electrons and holes recombine, and may generate light having an ultraviolet wavelength.

The active layer 126 may have any one of a single well structure, a multi well structure, a single quantum well structure, a multi quantum well (MQW) structure, a quantum dot structure, or a quantum line structure, and the active layer 126. The structure of is not limited to this.

The second conductive semiconductor layer 127 is formed on the active layer 126, and may be implemented as a compound semiconductor such as a group III-V group or a group II-VI. The second conductive semiconductor layer 127 may be a second semiconductor layer 127. Dopants may be doped. The second conductive semiconductor layer 127 is a semiconductor material having a composition formula of Inx5Aly2Ga1-x5-y2N (0≤x5≤1, 0≤y2≤1, 0≤x5 + y2≤1) or AlInN, AlGaAs, GaP, GaAs It may be formed of a material selected from GaAsP, AlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, or Ba, the second conductive semiconductor layer 127 doped with the second dopant may be a p-type semiconductor layer.

The second conductive semiconductor layer 127 may include 2-1 to 2-3

conductive semiconductor layers

127a, 127b, and 127c. The 2-1 conductivity type semiconductor layer 127a may have a smaller aluminum composition than the 2-2 conductivity type semiconductor layer 127b.

An electron blocking layer 129 may be disposed between the active layer 126 and the second conductive semiconductor layer 127. The electron blocking layer 129 blocks the flow of electrons supplied from the first conductive semiconductor layer 124 to the second conductive semiconductor layer 127 so that electrons and holes can be recombined in the active layer 126. You can increase your chances. The energy band gap of the electron blocking layer 129 may be larger than the energy band gap of the active layer 126 and / or the second conductive semiconductor layer 127.

The electron blocking layer 129 is a semiconductor material having a composition formula of In _x1 Al _y1 Ga ₁ _-x1- _y1 N (0≤x1≤1, 0≤y1≤1, 0≤x1 + y1≤1), for example AlGaN. , InGaN, InAlGaN, etc. may be selected, but is not limited thereto. In the electron blocking layer 129, a first layer 129b having a high aluminum composition and a second layer 129a having a low aluminum composition may be alternately disposed.

Referring to FIG. 2, the first conductive semiconductor layer 124, the barrier layer 126b, the well layer 126a, and the 2-1 to 2-3

conductive semiconductor layers

127a, 127b, and 127c are all It may comprise aluminum. Accordingly, the first conductive semiconductor layer 124, the barrier layer 126b, the well layer 126a, and the 2-1 to 2-3

conductive semiconductor layers

127a, 127b, and 127c may be AlGaN. However, it is not necessarily limited thereto.

The electron blocking layer 129 may have an aluminum composition of 50% to 90%. The blocking layer 129 may include a plurality of first blocking layers 129a having a relatively high aluminum composition and a plurality of second blocking layers 129b having a low aluminum composition. When the aluminum composition of the blocking layer 129 is less than 50%, the height of the energy barrier for blocking electrons may be insufficient, and the light emitted from the active layer 126 may be absorbed by the blocking layer 129, and the aluminum composition may be 90%. Exceeding the% may deteriorate the electrical characteristics of the semiconductor device.

The electron blocking layer 129 may include a first-first section 129-1 and a first-second section 129-2. As the first-first section 129-1 approaches the blocking layer 129, the aluminum composition may increase. The aluminum composition of the first-first section 129-1 may be 80% to 100%. That is, the first-first section 129-1 may be AlGaN or AlN. Alternatively, the first-first section 129-1 may be a superlattice layer in which AlGaN and AlN are alternately arranged.

The thickness of the first-first section 129-1 may be about 0.1 nm to 4 nm. If the thickness of the first-first section 129-1 is thinner than 0.1 nm, there may be a problem in that the movement of electrons may not be effectively blocked. In addition, when the thickness of the first-first section 129-1 is greater than 4 nm, there may be a problem in that the efficiency of injecting holes into the active layer is reduced.

The first-second section 129-2 may include an undoped section. The first-second section 129-2 may serve to prevent the dopant from being diffused from the second conductive semiconductor layer 127 to the active layer 126.

The thickness of the second-second conductive semiconductor layer 127b may be larger than 10 nm and smaller than 200 nm. For example, the thickness of the second conductivity-type semiconductor layer 127b may be 25 nm. When the thickness of the second conductivity-type semiconductor layer 127b is less than 10 nm, the resistance may increase in the horizontal direction, thereby decreasing current injection efficiency. In addition, when the thickness of the second conductivity-type semiconductor layer 127b is greater than 200 nm, the resistance may increase in the vertical direction, thereby decreasing current injection efficiency.

The aluminum composition of the second-conductive semiconductor layer 127b may be higher than that of the well layer 126a. The aluminum composition of the well layer 126a may be about 30% to 70% to generate ultraviolet light. If the aluminum composition of the 2-2 conductivity type semiconductor layer 127b is lower than that of the well layer 126a, the light extraction efficiency may be reduced because the 2-2 conductivity type semiconductor layer 127b absorbs light. Can be. However, in order to prevent the lowering of the crystallinity of the light emitting structure is not necessarily limited thereto. For example, the aluminum composition in a portion of the second-second conductive semiconductor layer 127b may be lower than that of the well layer 126a.

The aluminum composition of the second conductive semiconductor layer 127b may be greater than 40% and less than 80%. The aluminum composition of the second conductive semiconductor layer 127b has a problem of absorbing light when less than 40%, and a problem of deterioration of current injection efficiency when larger than 80%. For example, when the aluminum composition of the well layer 126a is 30%, the aluminum composition of the second-2 conductive semiconductor layer 127b may be 40%.

The aluminum composition of the second-first conductive semiconductor layer 127a may be lower than that of the well layer 126a. When the aluminum composition of the 2-1 conductive semiconductor layer 127a is higher than that of the well layer 126a, the resistance between the p-omic electrodes is increased, so that sufficient ohmic is not achieved and current injection efficiency is inferior. .

The aluminum composition of the second-first conductive semiconductor layer 127a may be greater than 1% and less than 50%. If it is larger than 50%, a sufficient ohmic may not be achieved with the p-omic electrode. If the composition is smaller than 1%, there is a problem of absorbing light because it is almost close to the GaN composition.

The thickness of the 2-1 conductive semiconductor layer 127a may be 1 nm to 30 nm, or 1 nm to 10 nm. As described above, the 2-1 conductivity type semiconductor layer 127a may absorb ultraviolet light because the composition of aluminum is low for ohmic. Therefore, it may be advantageous in terms of light output to control the thickness of the second-first conductivity-type semiconductor layer 127a as thin as possible.

However, when the thickness of the 2-1 conductive semiconductor layer 127a is controlled to 1 nm or less, the 2-1 conductive semiconductor layer 127a is not disposed in some sections, and the 2-2 conductive semiconductor layer 127b is not disposed. ) May be exposed to the outside of the light emitting structure 120. In addition, when the thickness is greater than 30 nm, the amount of light absorbed by the 2-1 conductivity type semiconductor layer 127a may be so large that the light output efficiency may decrease.

The thickness of the 2-1 conductive semiconductor layer 127a may be smaller than the thickness of the 2-2 conductive semiconductor layer 127b. The thickness ratio of the 2-2 conductive semiconductor layer 127b and the 2-1 conductive semiconductor layer 127a may be 1.5: 1 to 20: 1. When the thickness ratio is smaller than 1.5: 1, the thickness of the second conductive semiconductor layer 127b may be too thin, thereby reducing current injection efficiency. In addition, when the thickness ratio is greater than 20: 1, the thickness of the 2-1 conductivity type semiconductor layer 127a may be too thin, thereby reducing ohmic reliability.

The aluminum composition of the second-second conductive semiconductor layer 127b may be smaller as it moves away from the active layer 126. In addition, the aluminum composition of the 2-1 conductivity type semiconductor layer 127a may be smaller as it moves away from the active layer 126.

In this case, the aluminum reduction width of the 2-1 conductivity type semiconductor layer 127a may be greater than the aluminum reduction width of the 2-2 conductivity type semiconductor layer 127b. That is, the change rate in the thickness direction of the Al composition ratio of the 2-1 conductivity type semiconductor layer 127a may be greater than the change rate in the thickness direction of the Al composition ratio of the 2-2 conductivity type semiconductor layer 127b.

While the thickness of the 2-2 conductivity type semiconductor layer 127b is thicker than that of the 2-1 conductivity type semiconductor layer 127a, the aluminum composition should be higher than that of the well layer 126a, so that the decrease may be relatively slow. However, since the 2-1 conductivity type semiconductor layer 127a has a small thickness and a large variation in the aluminum composition, the decrease in the aluminum composition may be relatively large.

The 2-3 conductive semiconductor layer 127c may have a uniform aluminum composition. The thickness of the 2-3 conductive semiconductor layer 127c may be 20 nm to 60 nm. The aluminum composition of the second conductive semiconductor layer 127c may be 40% to 70%.

3 is a SIMS graph of the light emitting structure according to the first embodiment of the present invention, and FIG. 4 is an enlarged view of a portion of FIG. 3.

3 and 4, in the light emitting structure, the aluminum composition and the composition of the P-type impurity (Mg) may be changed in a direction of decreasing thickness. As the second conductive semiconductor layer 127 faces the surface direction of the second conductive semiconductor layer 127, the composition of aluminum may be lowered and the composition of the P-type impurity Mg may be increased.

The second conductive semiconductor layer 127 is formed of the second shortest distance W2 from the surface (a point of zero thickness, the first surface) to the second point P21 and the first point P11 from the surface. The ratio W1: W1 of the shortest distance W1 may be 1: 1.25 to 1: 100, or 1: 1.25 to 1:10.

When the ratio W2: W1 of the second shortest distance W2 and the first shortest distance W1 is smaller than 1: 1.25, the first shortest distance W1 and the second shortest distance W2 are closer to each other to change the aluminum composition. May cause a problem. In addition, when the ratio (W2: W1) is larger than 1: 100, the thickness of the second conductive semiconductor layer 127 becomes too thick, so that the crystallinity of the second conductive semiconductor layer 127 is lowered or applied toward the substrate. There is a problem that the stress to be strengthened can change the wavelength of the light emitted from the active layer.

Here, the first point P11 may be a point having the same composition as the aluminum composition of the well layer 126a closest to the second conductivity-type semiconductor layer 127 among the active layers. The range of the first point P11 may be defined as a spectrum measured by the SIMS. The range of the first point P11 may be defined as the second conductivity type semiconductor layer such as aluminum content in the well layer of the active layer.

In order to measure and define the first point P11, a method based on a SIMS spectrum may be applied, but is not limited thereto. As another example, TEM and XRD measurement methods may be applied, but may be simply defined through SIMS spectra.

The second point P21 may be a point at which the spectrum for the dopant (eg, Mg) of the second conductivity type semiconductor layer and the spectrum for aluminum cross each other in the SIMS spectrum.

In the measurement, the unit of the value for the dopant of the second conductivity type semiconductor layer may be different, but the spectrum including the inflection point for the aluminum composition of the second conductivity type semiconductor layer and the dopant of the second conductivity type semiconductor layer is different. The boundary region of the 2-1 conductivity type semiconductor layer 127a and the 2-2 conductivity type semiconductor layer 127b may be included within a range including an intersection point. Therefore, the boundary area of the conductive type 2-1 semiconductor layer 127a and the type 2-2 conductive semiconductor layer 127b can be measured, and the range thereof can be defined.

However, the present invention is not limited thereto, and the second point P21 may be a point located in an area in which the aluminum composition is 5% to 55%. When the aluminum composition of the second point P21 is less than 5%, the thickness of the 2-1 conductive semiconductor layer 127a may become too thin, which may lower power consumption efficiency of the semiconductor device, and exceeds 55%. In this case, the thickness of the 2-1 conductivity type semiconductor layer 127a may be so thick that light extraction efficiency may decrease. In this case, the aluminum composition of the second point P21 may be smaller than the aluminum composition of the first point P11. For example, the second point P21 may have an aluminum composition of 40% to 70%.

For example, the first shortest distance W1 may be 25 nm to 100 nm, and the second shortest distance W2 may be 1 nm to 20 nm.

The first difference H1 of the average aluminum composition of the electron blocking layer 129 and the aluminum composition at the first point P11 and the second of the aluminum composition of the average aluminum composition of the electron blocking layer and the second point P21 The ratio H1: H2 of the difference H2 may be from 1: 1.2 to 1:10.

When the ratio of the first difference to the second difference (H1: H2) is less than 1: 1.2, the change in aluminum composition in the section between the first point P11 and the second point is moderate, making it difficult to sufficiently lower the aluminum composition in the contact layer. There is. In addition, when the ratio (H1: H2) of the first difference and the second difference is greater than 1:10, the change in aluminum composition may be rapid, thereby increasing the probability of absorbing the light emitted from the active layer.

FIG. 5 is a SIMS graph of a light emitting structure according to a second embodiment of the present invention, FIG. 6 is a partially enlarged view of FIG. 5, and FIG. 7 is a seamless pattern of a light emitting structure according to a third embodiment of the present invention. SIMS) graph, and FIG. 8 is an enlarged view of a portion of FIG. 7.

5 to 8, the ratio W2: W1 of the second shortest distance W2 and the first shortest distance W1 described above is 1: 1.25 to 1: 100, or 1: 1.25 to 1:10. It can be seen that satisfactory. For example, referring to FIG. 8, it can be seen that the first point P13 and the second point P23 are disposed in close proximity to each other.

In addition, the first difference between the average aluminum composition of the electron blocking layer 129 and the aluminum composition at the first points P12 and P13, and the average aluminum composition of the electron blocking layer and the aluminum at the second points P22 and P23. It can be seen that the ratio (H1: H2) of the second difference in composition satisfies 1: 1.2 to 1:10.

When the condition is satisfied, the composition of aluminum on the surface of the second conductive semiconductor layer 127 may be adjusted to 1% to 10%.

9 is a conceptual diagram of a semiconductor structure according to an embodiment of the present invention, and FIG. 10 is a graph showing an aluminum composition ratio of a semiconductor structure according to an embodiment of the present invention.

9 and 10, a semiconductor device according to an embodiment may include a first conductive semiconductor layer 124, a second conductive semiconductor layer 127, and a first conductive semiconductor layer 124 and a second conductivity. And a semiconductor structure 120 including an active layer 126 disposed between the semiconductor semiconductor layers 127.

The semiconductor structure 120 according to the embodiment of the present invention may output light in the ultraviolet wavelength band. For example, the semiconductor structure 120 may output light in the near ultraviolet wavelength band (UV-A), may output light in the far ultraviolet wavelength band (UV-B), or light in the deep ultraviolet wavelength band (UV-C). ) Can be printed. The wavelength range may be determined by the composition ratio of Al of the semiconductor structure 120.

When the semiconductor structure 120 emits light in an ultraviolet wavelength band, each semiconductor layer of the semiconductor structure 120 includes In _x1 Al _y1 Ga ₁ _-x1- _y1 N (0 _≦ _x1 _≦ ₁ , 0 <y1) containing aluminum. ≦ 1, 0 ≦ x1 + y1 ≦ 1) material. Here, the composition of Al can be represented by the ratio of the total atomic weight and the Al atomic weight including the In atomic weight, the Ga atomic weight, and the Al atomic weight. For example, when the Al composition is 40%, the composition of Ga may be Al ₄₀ Ga ₆₀ N, which is 60%.

In addition, in the description of the embodiment, the meaning that the composition is low or high may be understood as the difference (and / or percentage point) of the composition% of each semiconductor layer. For example, when the aluminum composition of the first semiconductor layer is 30% and the aluminum composition of the second conductive semiconductor layer is 60%, the aluminum composition of the second conductive semiconductor layer is 30% higher than the aluminum composition of the first semiconductor layer. It can be expressed as higher.

The first conductive semiconductor layer 124 may be formed of a compound semiconductor such as a group III-V group or a group II-VI, and may be doped with a first dopant. The first conductive semiconductor layer 124 is a semiconductor material having a composition formula of In _x1 Al _y1 Ga ₁ _-x1 _-y1 N (0≤x1≤1, 0 <y1≤1, 0≤x1 + y1≤1), for example For example, it may be selected from AlGaN, AlN, InAlGaN and the like. The first dopant may be an n-type dopant such as Si, Ge, Sn, Se, or Te. When the first dopant is an n-type dopant, the first conductive semiconductor layer 124 doped with the first dopant may be an n-type semiconductor layer. However, the present invention is not limited thereto, and the first conductive semiconductor layer 124 may be a p-type semiconductor layer.

The first conductive semiconductor layer 124 may include the first-first conductive semiconductor layer 124a, the second-second conductive semiconductor layer 124c, and the first-first conductive semiconductor layer 124a and the first-first conductive semiconductor layer 124a. The intermediate layer 124b may be disposed between the two conductive semiconductor layers 124c.

The aluminum composition of the first-first conductive semiconductor layer 124a may be 50% to 80%. When the first-first conductivity type semiconductor layer 124a has an aluminum composition of 50% or more, light extraction efficiency may be improved by lowering the absorption rate of light (UV-C) in the deep ultraviolet wavelength band emitted from the active layer 126. When less than or equal to%, the current injection characteristic into the active layer 126 and the current spreading characteristic in the first-first conductive semiconductor layer 124a can be ensured.

The first-second conductivity type semiconductor layer 124c may be disposed closer to the active layer 126 than the first-first conductivity type semiconductor layer 124a. The aluminum composition of the 1-2 conductive semiconductor layer 124c may be lower than that of the 1-1 conductive semiconductor layer 124a.

When the semiconductor structure 120 emits light (UV-C) in the deep ultraviolet wavelength band, the aluminum composition of the 1-2 conductive semiconductor layer 124c may be 40% to 70%.

When the aluminum composition of the second conductive semiconductor layer 124c is 40% or more, light extraction efficiency may be improved by lowering the absorption rate of light (UV-C) emitted from the active layer 126 in the deep ultraviolet wavelength band. When less than or equal to%, the current injection characteristic into the active layer 126 and the current spreading characteristic in the 1-2 conductive semiconductor layer 124c can be secured.

The aluminum composition of the first-first conductive semiconductor layer 124a and the first-second conductive semiconductor layer 124c may be higher than that of the well layer 126a. Therefore, when the active layer 126 emits light having a wavelength in the ultraviolet region, the absorption rate may be lowered in the semiconductor structure 120 with respect to light having a wavelength in the ultraviolet region.

In addition, when the aluminum composition of the first-first conductivity-type semiconductor layer 124a is higher than the aluminum composition of the first-second conductivity-type semiconductor layer 124c, the semiconductor structure 120 may be formed in the active layer 126 by the difference in refractive index. It may be more advantageous for light to be extracted to the outside. Therefore, light extraction efficiency of the semiconductor structure 120 may be improved.

The thickness of the first-second conductive semiconductor layer 124c may be thinner than the thickness of the first-first conductive semiconductor layer 124a. The first-first conductive semiconductor layer 124a may be 130% or more of the thickness of the first-second conductive semiconductor layer 124c. According to this configuration, since the intermediate layer 124b is disposed after sufficiently securing the thickness of the first-first conductivity-type semiconductor layer 124a having a high aluminum composition, the crystallinity of the entire semiconductor structure 120 may be improved.

The aluminum composition of the intermediate layer 124b may be lower than that of the first conductive semiconductor layer 124 and the second conductive semiconductor layer 124. The intermediate layer 124b may serve to prevent damage to the active layer 126 by absorbing a laser beam irradiated onto the semiconductor structure 120 during a laser lift-off (LLO) process of removing a growth substrate. Therefore, the semiconductor device according to the embodiment may prevent damage to the active layer 126 during the laser lift-off (LLO) process, thereby improving light output and electrical characteristics.

In addition, when the intermediate layer 124b is in contact with the first electrode, the aluminum composition of the intermediate layer 124b may be a 1-1 conductive semiconductor layer in order to lower the resistance between the intermediate layer 124b and the first electrode to ensure current injection efficiency. 124a and lower than the aluminum composition of the 1-2 type conductive semiconductor layer 124c.

The thickness and aluminum composition of the intermediate layer 124b may be appropriately adjusted to absorb the laser irradiated to the semiconductor structure 120 during the LLO process. Therefore, the aluminum composition of the intermediate layer 124b may correspond to the wavelength of the laser light used in the LLO process.

When the laser for the LLO is 200 nm to 300 nm, the aluminum composition of the intermediate layer 124b may be 30% to 70% and the thickness may be 1 nm to 10 nm.

For example, when the wavelength of the LLO laser is lower than 270 nm, the composition of aluminum of the intermediate layer 124b may be increased to correspond to the LLO laser wavelength. For example, the aluminum composition of the intermediate layer 124b may be increased to 50% to 70%.

When the aluminum composition of the intermediate layer 124b is higher than the aluminum composition of the well layer 126a, the intermediate layer 124b may not absorb light emitted from the active layer 126. Therefore, light extraction efficiency can be improved. According to an embodiment, the LLO laser may have a wavelength lower than the light emission wavelength of the well layer 126a. Therefore, the intermediate layer 124b may have an appropriate aluminum composition so as to absorb the laser for the LLO while not absorbing the light emitted from the well layer 126a.

The intermediate layer 124b includes a first intermediate layer (not shown) having a lower aluminum composition than the first conductive semiconductor layer 124 and a second intermediate layer (not shown) having a higher aluminum composition than the first conductive semiconductor layer 124. It may also include. A plurality of first intermediate layers and a plurality of second intermediate layers may be arranged alternately.

The active layer 126 may be disposed between the first conductivity type semiconductor layer 124 and the second conductivity type semiconductor layer 127. The active layer 126 may include a plurality of well layers 126a and a plurality of barrier layers 126b. The well layer 126a includes a first carrier (electrons or holes) injected through the first conductive semiconductor layer 124 and a second carrier (holes or electrons) injected through the second conductive semiconductor layer 127. It is a meeting floor. When the first carrier (or second carrier) of the conduction band and the second carrier (or first carrier) of the electric conduction band are recombined in the well layer 126a of the active layer 126, the conduction band and the well layer of the well layer 126a ( Light having a wavelength corresponding to the difference (energy band gap) of the energy level of the household appliance band 126a may be generated.

The active layer 126 may include a plurality of well layers 126a and a barrier layer 126b. The well layer 126a and the barrier layer 126b may have a composition formula of In _x2 Al _y2 Ga ₁ _-x2- _y2 N (0≤x2≤1, 0 <y2≤1, 0≤x2 + y2≤1). . The well layer 126a may have an aluminum composition depending on the wavelength of light emitted.

The second conductive semiconductor layer 127 is formed on the active layer 126, and may be implemented as a compound semiconductor such as a group III-V group or a group II-VI. The second conductive semiconductor layer 127 may be a second semiconductor layer 127. Dopants may be doped.

The second conductivity-type semiconductor layer 127 is a semiconductor material or AlInN having a composition formula of In _x5 Al _y2 Ga ₁ _-x5- _y2 N (0≤x5≤1, 0 <y2≤1, 0≤x5 + y2≤1). , AlGaAs, GaP, GaAs, GaAsP, AlGaInP may be formed of a material selected from.

When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, or Ba, the second conductive semiconductor layer 127 doped with the second dopant may be a p-type semiconductor layer. However, the present invention is not limited thereto, and the second conductivity-type semiconductor layer 124 may be an n-type semiconductor layer.

The second conductive semiconductor layer 127 may include 2-1 to 2-3

conductive semiconductor layers

127a, 127b, and 127c. The 2-1 conductivity type semiconductor layer 127a may have a smaller aluminum composition than the 2-2 conductivity type semiconductor layer 127b and the 2-3 conductivity type semiconductor layer 127c.

The blocking layer 129 may be disposed between the active layer 126 and the second conductivity type semiconductor layer 127. The blocking layer 129 blocks the flow of the first carrier supplied from the first conductivity type semiconductor layer 124 to the second conductivity type semiconductor layer 127 to recombine electrons and holes in the active layer 126. You can increase your chances. The energy bandgap of the blocking layer 129 may be greater than the energy bandgap of the active layer 126 and / or the second conductivity type semiconductor layer 127. The blocking layer 129 may be defined as a portion of the second conductive semiconductor layer 127 because the second dopant is doped.

The blocking layer 129 is a semiconductor material having a composition formula of In _x1 Al _y1 Ga ₁ _-x1- _y1 N (0≤x1≤1, 0 <y1≤1, 0≤x1 + y1≤1), for example AlGaN, AlN, InAlGaN may be selected from, but is not limited thereto.

According to an embodiment, the first conductive semiconductor layer 124, the active layer 126, the second conductive semiconductor layer 127, and the blocking layer 129 may all include aluminum. Accordingly, the first conductive semiconductor layer 124, the active layer 126, the second conductive semiconductor layer 127, and the blocking layer 129 may have an AlGaN, InAlGaN, or AlN composition.

The blocking layer 129 may have a higher aluminum composition than the aluminum composition of the well layer 126a. For example, the blocking layer 129 may have an aluminum composition of 50% to 100%. If the aluminum composition of the blocking layer 129 is 50% or more, it may have a sufficient energy barrier to block the first carrier and may not absorb light emitted from the active layer 126.

The blocking layer 129 may include a first-first section 129a and a first-second section 129c.

An aluminum composition may be increased in the first-first section 129a in a direction from the first conductive semiconductor layer 124 to the second conductive semiconductor layer 127.

The aluminum composition of the first-first section 129a may be 80% to 100%. Therefore, the first-first section 129a of the blocking layer 129 may be the portion having the highest Al composition in the semiconductor structure 120.

The first-first section 129a may include AlGaN or AlN. Alternatively, the first-first section 129a may be a superlattice layer in which AlGaN and AlN are alternately arranged.

The thickness of the first-first section 129a may be about 0.1 nm to 4 nm. In order to effectively block the movement of the first carrier to the second conductive semiconductor layer 127, the thickness of the first-first section 129a may be 0.1 nm or more. In addition, the thickness of the first-first section 129a may be less than or equal to 4 nm to ensure the injection efficiency of injecting the second carrier from the second conductivity-type semiconductor layer 127 into the active layer 126.

In the first-first section 129a of the embodiment, the thickness of the first-first section 129-a is disposed to be 0.1 nm or more and 4 nm or less to ensure hole injection efficiency and electron blocking efficiency. It is not limited. For example, if it is necessary to selectively secure one of the first carrier blocking function and the second carrier injection function, it may be out of the above-mentioned numerical range.

The first to third sections 129b disposed between the first-first section 129a and the first-second section 129c may include an undoped section that does not include a dopant. Therefore, the first to third sections 129b may prevent the second dopant from being diffused from the second conductive semiconductor layer 127 to the active layer 126.

The second conductive semiconductor layer 127 may include 2-1 to 2-3

conductive semiconductor layers

127a, 127b, and 127c.

The thickness of the second-second conductive semiconductor layer 127b may be larger than 10 nm and smaller than 50 nm. For example, the thickness of the second conductivity-type semiconductor layer 127b may be 25 nm. When the thickness of the second-second conductive semiconductor layer 127b is 10 nm or more, current diffusion characteristics of the second-second conductive semiconductor layer 127b may be secured. In addition, when the thickness is 50 nm or less, the injection efficiency of the second carrier injected into the active layer 126 can be ensured, and the absorption rate of the light emitted from the active layer 126 in the 2-2 conductive semiconductor layer 127b is lowered. Can be.

The aluminum composition of the second-conductive semiconductor layer 127b may be higher than that of the well layer 126a. The aluminum composition of the well layer 126a may be about 30% to 70% to generate ultraviolet light. Therefore, the aluminum composition of the second conductive semiconductor layer 127b may be 40% or more and 80% or less.

When the aluminum composition of the second conductive semiconductor layer 127b is 40% or more, the problem of absorbing light may be improved, and when 80% or less, the problem of deteriorating current injection efficiency may be improved. For example, when the aluminum composition of the well layer 126a is 30%, the aluminum composition of the second-2 conductive semiconductor layer 127b may be 40%.

The aluminum composition of the second-first conductive semiconductor layer 127a may be lower than that of the well layer 126a. If the aluminum composition of the 2-1 conductivity type semiconductor layer 127a is higher than that of the well layer 126a, the resistance between the second electrodes may be increased, resulting in insufficient ohmicity and inferior current injection efficiency.

The aluminum composition of the 2-1 conductive semiconductor layer 127a may be 1% or more and 50% or less. If it is 50% or less, the resistance with the second electrode may be lowered. If the composition is 1% or more, the problem of absorbing light in the 2-1 conductive semiconductor layer 127a may be improved. The aluminum composition of the 2-1 conductive semiconductor layer 127a may be smaller than that of the intermediate layer 124b.

The thickness of the 2-1 conductive semiconductor layer 127a may be 1 nm to 30 nm. Since the 2-1 conductivity type semiconductor layer 127a may absorb ultraviolet light, it may be advantageous in terms of light output to control the thickness of the 2-1 conductivity type semiconductor layer 127a as thin as possible.

However, when the thickness of the 2-1 conductive semiconductor layer 127a is 1 nm or more, the resistance of the 2-1 conductive semiconductor layer 127a may be reduced, thereby improving electrical characteristics of the semiconductor device. In addition, when the thickness is 30 nm or less, light output efficiency may be improved by reducing the amount of light absorbed by the 2-1 conductive semiconductor layer 127a.

The thickness of the 2-1 conductive semiconductor layer 127a may be smaller than the thickness of the 2-2 conductive semiconductor layer 127b. The thickness ratio of the 2-1 conductive semiconductor layer 127a and the 2-2 conductive semiconductor layer 127b may be 1: 1.5 to 1:20. If the thickness ratio is greater than 1: 1.5, the thickness of the second conductive semiconductor layer 127b is increased, thereby improving current injection efficiency. In addition, when the thickness ratio is smaller than 1:20, the thickness of the 2-1 conductive semiconductor layer 127a is increased, thereby improving the problem of deterioration of crystallinity. If the thickness of the 2-1 conductive semiconductor layer 127a is too thin, the aluminum composition must be changed rapidly within the thickness range, so that crystallinity may be degraded.

At this time, the aluminum reduction width with respect to the thickness of the 2-1 conductivity type semiconductor layer 127a may be greater than the aluminum reduction width with respect to the thickness of the 2-2 conductivity type semiconductor layer 127b. That is, the change rate in the thickness direction of the Al composition ratio of the 2-1 conductivity type semiconductor layer 127a may be greater than the change rate in the thickness direction of the Al composition ratio of the 2-2 conductivity type semiconductor layer 127b.

The 2-1 conductivity type semiconductor layer 127a may have a lower aluminum composition than the well layer 126a for low contact resistance with the second electrode. Therefore, the 2-1 conductivity type semiconductor layer 127a may partially absorb light emitted from the well layer 126a.

Therefore, the thickness of the 2-1 conductivity type semiconductor layer 127a may be 1 nm or more and 30 nm or less in order to suppress the absorption of light.

As a result, the thickness of the 2-1 conductive semiconductor layer 127a may be relatively thin, but the change width of aluminum may be relatively large.

In contrast, the thickness of the 2-2 conductivity type semiconductor layer 127b is thicker than that of the 2-1 conductivity type semiconductor layer 127a, while the aluminum composition is higher than or equal to the well layer 126a, so that the decrease is relatively slow. can do.

Since the 2-1 conductivity type semiconductor layer 127a has a small thickness and a large variation in the aluminum composition with respect to the thickness, the composition of aluminum can be changed while growing relatively slowly.

The 2-3 conductive semiconductor layer 127c may have a uniform aluminum composition. The thickness of the 2-3 conductive semiconductor layer 127c may be 20 nm to 60 nm. The aluminum composition of the second conductive semiconductor layer 127c may be 40% to 70%. When the aluminum composition of the 2-3 conductive semiconductor layer 127c is 40% or more, the crystallinity of the 2-1 conductive semiconductor layer 127a and the 2-2 conductive semiconductor layer 127b may not decrease. When less than 70%, the problem of crystallinity deterioration caused by a drastic change in the aluminum composition of the 2-1 conductive semiconductor layer 127a and the 2-2 conductive semiconductor layer 127b can be prevented. It can improve the electrical characteristics.

As described above, the thickness of the 2-1 conductivity type semiconductor layer 127a is 1 nm to 10 nm, the thickness of the 2-2 conductivity type semiconductor layer 127b is 10 nm to 50 nm, and the 2-3 conductivity type semiconductor layer. The thickness of 127c may be 20 nm to 60 nm.

Therefore, the ratio of the thickness of the 2-1 conductivity type semiconductor layer 127a and the total thickness of the second conductivity type semiconductor layer 127 may be 1: 3 to 1: 120. If greater than 1: 3, the 2-1 conductive semiconductor layer 127a can secure electrical characteristics (for example, operating voltage) of the semiconductor device, and if less than 1: 120, optical properties of the semiconductor device (for example, For example, the light output can be secured. However, the present invention is not limited thereto, and the ratio of the thickness of the second conductive semiconductor layer 127a to the total thickness of the second conductive semiconductor layer 127 may be 1: 3 to 1:50 or 1: 3 to 1 :. May be 70.

The second conductive semiconductor layer 127 according to an embodiment of the present invention may include a first point P1 having the highest aluminum composition and a third point P3 having the lowest aluminum composition in the semiconductor structure. . Here, the first point P1 may be the first-first section 129a of the blocking layer 129 having the highest aluminum composition, and the third point P3 may be the second-first conductive semiconductor layer having the lowest aluminum ( 127a).

The first conductive semiconductor layer 124 may include a second point P2 having the highest aluminum composition and a fourth point P4 having the lowest aluminum composition in the first conductive semiconductor layer. The second point P2 may be the first-first conductivity-type semiconductor layer 124a and / or the second-second conductivity-type semiconductor layer 124c, and the fourth point P4 may be the intermediate layer 124b. .

The aluminum composition of the first-first section 129a may be 80% to 100%. The aluminum composition of the 2-1 conductive semiconductor layer 127a may be 1% or more and 50%. In this case, the aluminum composition of the 2-1 conductivity type semiconductor layer 127a may be smaller than that of the well layer 126a.

Therefore, the ratio of the aluminum composition between the third point P3 and the first point P1 may be 1: 4 to 1: 100. When the ratio of the aluminum composition is 1: 4 or more, the aluminum composition of the first point P1 is increased to effectively block the first carrier from passing through the second conductive semiconductor layer. In addition, when the ratio of the aluminum composition is less than 1: 100, the aluminum of the third point P3 may increase, thereby improving the problem of absorbing the light of the third point P3.

The aluminum composition of the first-first conductive semiconductor layer 124a may be 50% to 80%. The aluminum composition of the intermediate layer 124b may be 30% to 70%. In this case, the aluminum composition of the intermediate layer 124b may be smaller than that of the first-first conductive semiconductor layer. Therefore, the ratio of the aluminum composition between the fourth point P4 and the second point P2 may be 1: 0.5 to 1: 0.9.

When the aluminum composition ratio is greater than or equal to 1: 0.5, the aluminum composition of the first-first conductivity type semiconductor layer 124a may be increased to improve crystallinity. In addition, when the aluminum composition ratio is 1: 0.9 or less, the aluminum composition of the intermediate layer 124b is increased, thereby improving the problem of absorbing light in the ultraviolet wavelength band.

11A and 11B are SIMS data of a semiconductor structure according to an embodiment of the present invention, and FIGS. 11C and 11D are SIMS of a semiconductor structure according to another embodiment of the present invention. ), FIG. 12 is a view showing the aluminum relative ion intensity of FIGS. 11A to 11D, FIG. 13A is an enlarged view of the SIMS data of FIG. 12A, and FIG. 13B is FIG. 12B. Is a diagram obtained by converting SIMS data into a linear scale.

Referring to FIG. 11A, the semiconductor structure may include aluminum (Al), gallium (Ga), a first dopant, a second dopant, and an oxygen (ie, the first conductive semiconductor layer 124) to the second conductive semiconductor layer 127. O), the composition of carbon (C) may change. The first dopant may be silicon (Si) and the second dopant may be magnesium (Mg), but is not limited thereto.

The SIMS data may be analytical data by time-of-flight secondary ion mass spectrometry (TOF-SIMS).

Sims (SIMS) data can be analyzed by irradiating primary ions to the surface of the target and counting the number of secondary ions released. At this time, the primary ion may be selected from O ₂ ⁺ , Cs ⁺ Bi ^+, etc., the acceleration voltage may be adjusted within 20 to 30 keV, the irradiation current may be adjusted from 0.1 pA to 5.0pA, the irradiation area May be 20 nm × 20 nm.

The SIMS data may collect secondary ion mass spectra while gradually etching toward the first conductivity type semiconductor layer from the surface of the second conductivity type semiconductor layer (point of zero depth).

However, the present invention is not limited thereto, and measurement conditions for detecting AlGaN-based and / or GaN-based semiconductor materials and first and second dopant materials may be variously used.

In addition, the results of SIMS analysis can be interpreted as a spectrum of secondary ionic strength or doping concentration of a material, which may include noise occurring within 0.9 to 1.1 times in the analysis of secondary ionic strength or doping concentration. Can be. Thus, a description of “equal / identical” may refer to a noise comprising from 0.9 times to 1.1 times greater than one particular secondary ionic strength or doping concentration.

In the SIMS data of FIGS. 11A to 11D, aluminum and gallium are spectral data for secondary ionic strength, and first dopant, second dopant, oxygen, and carbon are data obtained by measuring doping concentration. That is, FIGS. 11A to 11D show sims data and doping concentration data in one drawing.

Referring to FIG. 11A, although the spectrum of the aluminum ion intensity and the portion of the concentration spectra of the first and second dopants are shown to cross each other, the data on the ionic strength and the concentration of the dopant may be independent of each other.

By way of example, the ionic strength of aluminum and the doping concentration of the second dopant are intersected near the surface (a point of zero depth), but the reference point of the doping concentration (lowest point on the left Y axis of the drawing) is lowered. When set, the doping concentration graph can be lowered on the data. For example, if the reference point of the second dopant doping concentration is lowered from 1.00E + 14 to 1.00E + 12, since the concentration graph of the second dopant is lowered in the drawing, the second dopant data and the aluminum data may not intersect.

The method for measuring the concentrations of the first dopant, the second dopant, oxygen and carbon is not particularly limited. In addition, in the present embodiment, the vertical axis (Y axis) is illustrated as converted to a logarithmic scale.

It can be seen that the ionic strength of aluminum gradually increases with increasing depth at the surface and then increases and decreases after the highest strength point. In the GaN-based semiconductor material, since Al atoms replace the Ga atoms to form an AlGaN material, the ionic strength of gallium may be symmetric with the ionic strength of aluminum.

Ionic strength according to the embodiment may be increased or decreased depending on the measurement conditions. However, as the intensity of primary ions increases, the intensity graph of secondary ions (aluminum ions) increases as a whole, and as the intensity of primary ions decreases, the intensity graph of secondary ions (aluminum ions) may decrease as a whole. Therefore, the change in the ionic strength in the thickness direction may be similar even if the measurement conditions are changed.

The doping concentration of the second dopant is highest at the surface and may gradually decrease with distance from the surface. The second dopant may be present in all regions of the second conductive semiconductor layer and in some regions of the active layer, but is not limited thereto. The second dopant may be disposed only in the second conductive semiconductor layer, but may be diffused to the active layer. Thus, the implantation efficiency of the second dopant implanted into the active layer can be improved. However, when the second dopant is diffused to the first conductivity type semiconductor layer, leakage current of the semiconductor device and / or non-emitting recombination of the first and second carriers may occur, thereby reducing reliability and / or luminous efficiency of the semiconductor device. .

The first dopant may have a section R1 in which the concentration is lower than the concentration of oxygen in the section between the first conductive semiconductor layer and the active layer. The first dopant may be partly distributed in the active layer. Therefore, the injection efficiency of the first carrier to be injected into the active layer can be improved, and the efficiency of luminous recombination of the first carrier and the second carrier in the active layer can be improved.

11B to 11D also show the same tendency as FIG. 11A.

12 and 13A, the aluminum ion strength may include first to sixth points P1, P2, P3, P4, P5, and P6. FIG. 12A is the aluminum ion intensity of FIG. 11A, FIG. 12B is the aluminum ion intensity of FIG. 11B, FIG. 12C is the aluminum ion intensity of FIG. 11C, and FIG. ) Is the aluminum ion strength of FIG. 11D.

12 (c) and 12 (d) are different from those of FIG. 12 except for having an uneven section P7 in which the ionic strength changes between the first point P1 and the third point P3. It may have a distribution similar to the aluminum ion intensity distribution of a). For example, the embodiment of FIGS. 12C and 12D may have a structure in which a superlattice layer is further disposed on the blocking layer.

The ionic strength of aluminum at the first point P1 may be the highest in the semiconductor structure 120. Since the aluminum has the highest ionic strength at the first point P1, it is possible to prevent the first carrier from non-luminescent recombination with the second carrier in the second conductivity type semiconductor layer. Therefore, the light output of the semiconductor element can be improved. The first point P1 may be an area corresponding to the first-first section 129a of the blocking layer 129, but is not limited thereto.

The second ionic strength of the second point P2 is the point where the ionic strength of the aluminum is the highest among the points of the ionic strength of the aluminum extending from the first point P1 in the first direction (the direction in which the depth increases, D). Can be.

The second point P2 may be the point where the ionic strength of aluminum is the highest in the first conductivity type semiconductor layer 124, and the point nearest the active layer 126 in the first conductivity type semiconductor layer 124. have.

The second point P2 may balance the concentration or density of the first and second carriers recombined in the active layer by lowering the first carrier energy injected from the first conductive semiconductor layer 124 toward the active layer. Therefore, light emission efficiency may be improved to improve light output characteristics of the semiconductor device.

The third ionic strength of the third point P3 may be a point at which the ionic strength of aluminum is lowest in the direction toward the surface of the semiconductor structure 120 from the first point P1 (the direction opposite to the first direction).

When the third point P3 and the second electrode are in contact with each other, the resistance between the third point P3 and the second electrode may be low because the aluminum has the lowest ionic strength of the third point P3, and thus the second electrode Through this, the current injection efficiency injected into the semiconductor structure 120 may be secured.

The fourth ionic strength of the fourth point P4 may be a point at which the ionic strength of aluminum is lowest in the first direction at the second point P2.

The fourth point P4 may prevent the active layer from being damaged by the LLO process by absorbing the laser to prevent the laser from penetrating into the active layer when the Laser Lift-Off (LLO) process is applied during the semiconductor device process. have.

In addition, when the first point P4 is in contact with the fourth point P4, the resistance between the first electrode and the fourth point P4 may be lowered to improve the injection efficiency of the current injected into the semiconductor structure. In this regard, the ionic strength of the aluminum at the fourth point P4 may be lowest in the first direction at the second point P2.

The fifth point P5 may be disposed between the second point P2 and the fourth point P4. The ionic strength of aluminum at the fifth point P5 may have an ionic strength between the second point P2 and the fourth point P4. The fifth point P5 may be one specific point and may constitute one layer. The current injected through the fourth point P4 may be uniformly distributed in the layer including the fifth point P5 so that the density of the area of the current injected into the active layer may be improved.

In addition, a point (or layer) having the same or similar ionic strength as aluminum as the fifth point P5 may be spaced apart from the fourth point P4 in the first direction D. FIG. That is, it may have a section in which the ionic strength rises in the first direction from the fourth point P4. Therefore, the fourth point P4 may be disposed between the points (or layers) having the ionic strength of aluminum of the fifth point P5. However, the present invention is not limited thereto, and the ionic strength of aluminum in a region spaced apart from the fifth point P5 in the first direction D and farther in the first direction D than the fourth point P4 is the fifth point ( It may have a higher ionic strength than P5).

The tenth point P10 may be disposed between the first point P1 and the third point P3 and has the smallest ion intensity between the first point P1 and the second point P2 ( It may have the same ionic strength of aluminum as S22).

The thickness of the region between the tenth point P10 and the third point P3 may be 1 nm or more and 30 nm to suppress absorption of light emitted by the semiconductor device and lower contact resistance with the second electrode.

In addition, the third point P3 electrically connected to the second electrode may have a lower electrical conductivity than the fourth point P4 connected to the first electrode. Therefore, the ionic strength of the third point P3 may be smaller than the ionic strength of the fourth point P4.

Accordingly, the average rate of change of the ionic strength of aluminum between the tenth point P10 and the third point P3 is greater than the average rate of change of the ionic strength of aluminum between the first point P1 and the tenth point P10. Can be. Here, the average change rate may be a value obtained by dividing the maximum change width of the aluminum ion strength by the thickness.

The area S11 between the third point P3 and the tenth point P10 is a section in which the ionic strength of aluminum decreases as it approaches the surface S0, and the ionic strength of aluminum as it approaches the surface S0. May have an inversion section P6 that does not decrease. The inversion section P6 may be a section in which the aluminum ion intensity increases or maintains as the surface S0 approaches.

When the inversion section P6 is disposed in the region between the third point P3 and the tenth point P10, the current injected into the third point P3 can be spread evenly, so that the current density injected into the active layer can be controlled evenly. Can be. Therefore, the light output characteristics, electrical characteristics, and reliability of the semiconductor device may be improved.

The reversal section P6 can be controlled via temperature. For example, the region between the third point P3 and the tenth point P10 may control the composition of aluminum by controlling the temperature. In this case, when the temperature is lowered too rapidly, the crystallinity of the second conductivity-type semiconductor layer may be greatly reduced.

Therefore, in the process of continuously lowering and raising the temperature, the aluminum may be instantaneously contained at the moment when the lowering temperature is increased again, thereby forming the inversion section P6.

That is, after forming the tenth point P10 having the same ionic strength of aluminum as the point where the ionic strength of aluminum is the lowest in the active layer, the composition of the aluminum is changed through the temperature in the process until the third point P3 is formed. It can be controlled, and in this process, the inversion section P6 may be arranged to secure the crystallinity of the second conductivity type semiconductor layer and to secure the current diffusion characteristics.

However, the present invention is not limited thereto, and in another embodiment, the ionic strength of the aluminum is continuously increased as the second point P10 is moved from the tenth point P10 to the third point P3 in order to further secure the current injection characteristic. May be arranged to decrease.

Referring to FIG. 13A, the semiconductor structure on the aluminum ion intensity graph may include a first section S1, a second section S2, and a third section S3 in a direction of increasing depth.

The first section S1 may be disposed between the first point P1 and the third point P3 and may be formed of a second conductive semiconductor layer. The second section S2 may be disposed between the first point P1 and the second point P2 and may be composed of the active layer 126. The third section S3 is a section disposed in a direction from the second point P2 toward the first direction, and may be composed of the first conductivity type semiconductor layer 124.

The second section S2 may be disposed between the first point P1 and the second point P2. As described above, the first point P1 is a point where the aluminum ion intensity is the highest in the semiconductor structure, and the second point P2 is spaced apart in the first direction away from the surface (increasing in depth), It may be a point having an ionic strength higher than the maximum ionic strength (the ionic strength of the peak) of the second section (S2).

However, the present invention is not limited thereto, and the second point may have the same height as the fifth point. In this case, the second section may be disposed between the first point and the fifth point.

The second section S2 is a section corresponding to the active layer 126 and may have a plurality of peaks S21 and a plurality of valleys S22. Valley S22 may be the ionic strength of the well layer, and peak S21 may be the ionic strength of the barrier layer.

At this time, the ionic strength ratio M1 of the point where the ionic strength is lowest in the valley S22 and the first point P1 may be 1: 0.4 or more and 1: 0.6 or less, and the ions of the valley S22 and the peak S21 may be The intensity ratio M2 may be 1: 0.5 or more and 1: 0.75 or less.

The first point P1 and the third point disposed closer to the surface than the active layer when the ratio of the lowest ionic strength of the valley S22 and the ionic strength M1 of aluminum at the first point P1 is 1: 0.4 or more. The crystallinity of the second conductive semiconductor layer between (P3) can be secured, and the probability of the light emitting recombination in the active layer can be increased by preventing the first carrier from being injected into the second conductive semiconductor layer. Therefore, the light output characteristics of the semiconductor device can be improved.

In addition, when the ionic strength ratio M1 is 1: 0.6 or less, it is possible to secure crystallinity of the second conductive semiconductor layer between the first point P1 and the third point P3 disposed closer to the surface than the active layer. .

When the ionic strength ratio M2 of the valley S22 and the peak S21 is 1: 0.5 or more, the carrier exits from the well layer included in the active layer to the first conductive semiconductor layer and / or the second conductive semiconductor layer. The barrier layer can be effectively prevented to increase the light emitting recombination probability in the well layer, thereby improving the light output characteristics of the semiconductor device.

In addition, when the ionic strength ratio (M2) is less than 1: 0.75, the stress due to the lattice constant difference between the well layer and the barrier layer is reduced to secure the crystallinity of the semiconductor structure, and the wavelength change and / or luminescence recombination probability by the strain It can be improved.

The ratio (M1: M2) of these two ratios may satisfy 1: 0.3 to 1: 0.8. Therefore, a section in which the ratio M1: M2 of the two ratios satisfies 1: 0.3 to 1: 0.8 may be a section in which the actual active layer is disposed.

The ionic strength of the third point P3 may be smaller than the lowest ionic strength (the ionic strength of the well layer) in the second section S2. In this case, the active layer may be included in the second section S2 and may be defined as an area between the valley P8 closest to the first point P1 and the valley P9 farthest from the first point P1. .

In addition, an interval between neighboring valleys S22 may be smaller than an interval between the first point P1 and the second point P2. This is because the thickness of the well layer and the barrier layer is smaller than the thickness of the entire active layer 126.

The first section S1 may include a surface region S11 having a lower ionic strength than the fourth point P4. In this case, the surface area S11 may have a lower ionic strength toward the opposite direction to the first direction D. FIG.

The first intensity difference D1 between the second point P2 and the fourth point P4 on the seamless data, and the ratio of the second intensity difference D2 between the first point P1 and the third point P3 ( D1: D2) may be 1: 1.5 to 1: 2.5. When the ratio (D1: D2) of the difference in strength is 1: 1.5 or more (for example, 1: 1.6), the second strength difference D2 becomes large, so that the aluminum composition at the first point P1 can be sufficiently lowered. Thus, the contact resistance with the second electrode can be lowered.

In addition, when the ratio (D1: D2) of the difference in intensity is 1: 2.5 or less (for example, 1: 2.4), the aluminum composition becomes too low and the light emitted from the active layer 126 emits light from the 2-1 conductive semiconductor layer 127a. Absorption in the optical element of the semiconductor device can be solved.

The ratio (D3: D4) of the third intensity difference D3 between the seventh point P7 and the first point P1 and the fourth intensity difference D4 between the fourth point P4 and the third point P3 May be 1: 0.2 to 1: 2 or 1: 0.2 to 1: 1.

If the ratio of the difference in strength is greater than or equal to 1: 0.2, the fourth strength difference D4 becomes relatively large, so that the aluminum composition can be sufficiently lowered. Thus, the contact resistance with the second electrode can be reduced. In addition, when the composition difference is 1: 2 or less, the problem that the aluminum composition changes rapidly within the thickness range of the 2-1 conductive semiconductor layer 127a and the crystallinity is lowered can be improved. In addition, the aluminum composition may be so low that the light emitted from the active layer 126 may be absorbed by the 2-1 conductivity type semiconductor layer 127a.

Conventionally, a thin GaN layer is inserted for ohmic contact between the second conductive semiconductor layer 127 and the electrode. However, in this case, since the GaN layer in contact with the electrode does not contain aluminum, the aluminum ion strength of the third point P3 is not measured or rapidly decreases. Therefore, the ratio D1: D2 of the first intensity difference D1 and the second intensity difference D2 and the ratio D3: D4 of the third intensity difference D3 and the fourth intensity difference D4 are described above. It can be out of range.

The ratio of the intensity difference between the first point P1 and the third point P3 and the intensity difference between the fifth point P5 and the third point P3 may be 1: 0.5 to 1: 0.8. When the ratio of the intensity differences is greater than 1: 0.5, the intensity of the fifth point P5 may be increased, thereby improving crystallinity and improving light extraction efficiency. In addition, when the ratio of the intensity differences is smaller than 1: 0.8, lattice mismatch between the active layer 126 and the first conductivity type semiconductor layer 124 may be alleviated.

An ion intensity ratio P3: P1 between the third point P3 and the first point P1 may be 1: 2 to 1: 4. When the ionic strength ratio between the third point P3 and the first point P1 is 1: 2 or more (eg, 1: 2.1), the strength of the third point P3 is sufficiently lowered to increase the contact resistance with the second electrode. Can be lowered. In addition, when the ratio of the ionic strength of the third point P3 and the first point P1 is less than or equal to 1: 4 (eg, 1: 3.9), the aluminum strength of the third point P3 may be increased. Therefore, the problem of absorbing light at the third point P3 can be improved.

An ion strength ratio between the tenth point P10 and the first point P1 may be 1: 1.3 to 1: 2.5. When the ionic strength ratio between the tenth point P10 and the first point P1 is 1: 1.3 or more, the ionic strength of the first point P1 is increased to effectively block the first carrier from passing through the active layer. In addition, when the ionic strength ratio between the tenth point P10 and the first point P1 is 1: 2.5 or less, the ionic strength of the tenth point P10 is increased, so that the well layer may generate light in the ultraviolet wavelength range. .

An ion intensity ratio between the third point P3 and the fourth point P4 may be 1: 1.1 to 1: 2. When the ionic strength ratio between the third point P3 and the fourth point P4 is 1: 1.1 or more, the ionic strength of the fourth point P4 is increased to reduce the absorption rate of light in the ultraviolet wavelength band. In addition, when the ionic strength ratio between the third point P3 and the fourth point P4 is 1: 2 or less, sufficient ionic strength may be secured at the third point to reduce light absorption in the ultraviolet wavelength band.

The ratio of the ionic strength of the second point P2 and the first point P1 may be 1: 1.1 to 1: 2. When the ratio of the ionic strength between the second point P2 and the first point P1 is greater than or equal to 1: 1.1, the ionic strength of the first point P1 may be increased to effectively block the first carrier from passing through the active layer. In addition, when the ratio of the ionic strength of the second point P2 and the first point P1 is less than or equal to 1: 2, the concentration of the first carrier and the concentration of the second carrier, which is injected into the active layer and undergoes luminescence recombination, may be balanced. Therefore, the amount of light emitted by the semiconductor element can be improved.

An ion strength ratio between the fourth point P4 and the second point P2 may be 1: 1.2 to 1: 2.5. When the ionic strength ratio between the fourth point P4 and the second point P2 is 1: 1.2 or more, the resistance between the fourth point P4 and the first electrode can be lowered. In addition, when the ionic strength ratio between the fourth point P4 and the second point P2 is less than or equal to 1: 2.5, the ionic strength of the fourth point P4 may increase to reduce the absorption rate of light in the ultraviolet wavelength band.

An ion strength ratio between the fifth point P5 and the second point P2 may be 1: 1.1 to 1: 2.0. In an exemplary embodiment, the semiconductor structure emitting deep ultraviolet light may be formed of a GaN-based material including a large amount of aluminum, compared to a semiconductor structure emitting blue light. Thus, the ratio of the mobility of the first carrier to the mobility of the second carrier may be different compared to the semiconductor structure emitting blue light. That is, when the ionic strength ratio between the fifth point P5 and the second point P2 is 1: 1.1 or more, the concentration of the first carrier injected into the active layer can be ensured. In addition, when the ionic strength ratio between the fifth point P5 and the second point P2 is less than or equal to 1: 2.0, the ionic strength of the fifth point P5 may be increased to improve crystallinity.

An ion strength ratio between the fourth point P4 and the fifth point P5 may be 1: 1.1 to 1: 2.0. When the ionic strength ratio between the fourth point P4 and the fifth point P5 is 1: 1.1 or more, the ionic strength of the fifth point P5 may be increased to improve crystallinity. In addition, when the ionic strength ratio between the fourth point P4 and the fifth point P5 is less than or equal to 1: 2.0, the ionic strength of the fourth point P4 may be increased to reduce the absorption rate of light in the ultraviolet wavelength band.

In FIG. 12 and FIG. 13A, the aluminum ion intensity is expressed in a logarithmic scale, but is not necessarily limited thereto, and may be converted to the linear scale as shown in FIG. 13B.

According to the embodiment, since the third point P3 includes aluminum, it can be seen that the first point P1 and the third point P3 are substantially disposed in one order. The order may be a level unit of ionic strength. For example, the first order may be 1.0 × 10 ¹ and the second order may be 1.0 × 10 ² . Each order may also have 10 sub-levels.

For example, the first sub level of the first order is 1.0 × 10 ¹ , the second sub level of the first order is 2.0 × 10 ¹ , The third sub level of the first order may be 3.0 × 10 ¹ , the ninth sub level of the first order is 9.0 × 10 ^1, and the tenth sub level of the first order may be 1.0 × 10 ² . That is, the tenth sub level of the first order may be the same as the first sub level of the second order. In FIG. 13B, dotted lines are displayed for every two sublevels.

FIG. 14A is a conceptual diagram of a second conductive semiconductor layer according to an embodiment of the present invention, and FIG. 14B is AFM data of measuring the surface of a second conductive semiconductor layer according to an embodiment of the present invention. It is AFM data which measured the surface of the GaN thin film, and FIG. 14D is AFM data which measured the surface of the 2nd conductivity type semiconductor layer grown at high speed.

Referring to FIG. 14A, the second conductivity-type semiconductor layer 127 according to the embodiment may include 2-1 to 2-3 conductivity-

type semiconductor layers

127a, 127b, and 127c. The 2-1 conductivity type semiconductor layer 127a may be a contact layer in contact with the second electrode. Characteristics of each layer may be applied as described above.

The surface of the second-first conductive semiconductor layer 127a may include a plurality of clusters C1. The cluster C1 may be a protrusion protruding from the surface. For example, the cluster C1 may be a protrusion protruding about 10 nm or 20 nm or more based on the average surface height. The cluster C1 may be formed by lattice mismatch between aluminum (Al) and gallium (Ga).

The 2-1 conductivity type semiconductor layer 127a according to the embodiment includes aluminum, and has a large change rate of aluminum with respect to a thickness, and a single layer on the surface because the thickness is thinner than other layers. It may not be formed and may be formed on the surface in the form of a cluster C1. The cluster C1 may include Al, Ga, N, Mg, and the like. However, it is not necessarily limited thereto.

Referring to FIG. 14B, a cluster C1 having a relatively bright dot shape may be identified on the surface of the second conductivity-type semiconductor layer 127. According to the embodiment, since the aluminum composition of the 2-1 conductivity type semiconductor layer 127a is 1% to 10%, it may occur in the form of a cluster C1 to increase the junction area. Thus, the electrical characteristics can be improved.

On the surface of the second conductivity-type semiconductor layer 127, one to eight clusters C1 may be observed per 1 μm ² on average. Here, the average value may be an average of values measured at about 10 or more different locations. As a result of measuring the point E1 in FIG. 14B, 12 clusters C1 were observed per unit area having a width of 2 μm. Cluster (C1) was measured only clusters protruding at least 25nm from the surface. By adjusting the contrast in the AFM image, only the clusters protruding more than 25nm from the surface can be adjusted.

The density of the cluster C1 converting the unit based on the measurement result may be 1 × 10 ⁻⁸ / cm ² to 8 × 10 ⁻⁶ / cm ² . If the density of the cluster C1 is less than 1 × 10 ⁻⁸ / cm ² , the contact area may be relatively reduced, and the contact resistance with the second electrode may be increased.

In addition, when the density of the cluster C1 is greater than 8 × 10 ⁻⁶ / cm ² , light emitted from the active layer 126 may be absorbed by Ga included in some clusters, thereby reducing light output.

According to the embodiment, since the density of the cluster C1 satisfies 1 × 10 ⁻⁸ / cm ² to 8 × 10 ⁻⁶ / cm ² , the contact resistance with the second electrode can be lowered without lowering the light output. .

Referring to FIG. 14C, it can be seen that no cluster is observed on the surface of the GaN thin film. This may be because the density of the clusters forms a layer. Therefore, it can be seen that when the GaN thin film is formed between the second conductive semiconductor layer and the second electrode, no cluster is formed at the contact surface.

Referring to FIG. 14D, even when the second conductivity-type semiconductor layer is rapidly grown, it can be seen that the cluster does not grow well. Therefore, even when the composition of aluminum is controlled to be 1% to 10% on the surface of the second conductivity-type semiconductor layer, it can be seen that the cluster C1 is not formed when the growth rate is fast. For example, FIG. 14D is a photograph of a surface of P-AlGaN grown at a rate of 0.06 nm / s.

That is, in order to form a plurality of clusters C1 in the second conductivity-type semiconductor layer 127, it may be confirmed that the aluminum composition is 1% to 10% in the surface layer and the growth rate of the surface layer should be sufficiently slow.

In an embodiment, the growth rate of the 2-1 conductivity type semiconductor layer may be slower than that of the 2-2 and 2-3 conductivity type semiconductor layers. For example, the ratio of the growth rate of the 2-2 conductivity type semiconductor layer and the growth rate of the 2-1 conductivity type semiconductor layer may be 1: 0.2 to 1: 0.8. When the growth rate is less than 1: 0.2, the growth rate of the 2-1 conductive semiconductor layer is so slow that Ga is etched at a high temperature at which AlGaN is grown, and AlGaN having high Al composition is grown to decrease ohmic characteristics. If the growth rate is greater than 1: 0.8, the growth rate of the 2-1 conductive semiconductor layer may be too high, leading to a decrease in crystallinity.

FIG. 15 is a conceptual diagram of a semiconductor device according to an embodiment of the present disclosure. FIGS. 16A and 16B are diagrams for describing a configuration in which light output is improved according to a change in the number of recesses, and FIG. 17 is A of FIG. 15. It is a partial enlarged view.

Referring to FIG. 15, a semiconductor device according to an embodiment may include a semiconductor structure 120 including a first conductive semiconductor layer 124, a second conductive semiconductor layer 127, and an active layer 126, and a first conductive layer. The first electrode 142 may be electrically connected to the type semiconductor layer 124, and the second electrode 146 may be electrically connected to the second conductive semiconductor layer 127.

The first conductive semiconductor layer 124, the active layer 126, and the second conductive semiconductor layer 127 may be disposed in the first direction (Y direction). Hereinafter, the first direction (Y direction), which is the thickness direction of each layer, is defined as the vertical direction, and the second direction (X direction) perpendicular to the first direction (Y direction) is defined as the horizontal direction.

The above-described structure may be applied to the semiconductor structure 120 according to the embodiment. The semiconductor structure 120 may include a plurality of recesses 128 disposed through the second conductivity type semiconductor layer 127 and the active layer 126 to a portion of the first conductivity type semiconductor layer 124. .

The first electrode 142 may be disposed on an upper surface of the recess 128 to be electrically connected to the first conductive semiconductor layer 124. The second electrode 146 may be disposed under the second conductive semiconductor layer 127.

The first electrode 142 and the second electrode 146 may be ohmic electrodes. The first electrode 142 and the second electrode 146 are indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IZO), and indium gallium zinc oxide (IGZO). ), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IZON (IZO Nitride), AGZO (Al-Ga ZnO), IGZO (In-Ga) ZnO), ZnO, IrOx, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au, or Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, At least one of Ru, Mg, Zn, Pt, Au, and Hf may be formed, but is not limited thereto. In exemplary embodiments, the first electrode may have a plurality of metal layers (eg, Cr / Al / Ni), and the second electrode may be ITO.

Referring to FIG. 16A, when the GaN-based semiconductor structure 120 emits ultraviolet rays, the GaN-based semiconductor structure 120 may include aluminum. When the aluminum composition of the semiconductor structure 120 is increased, current dispersal characteristics of the semiconductor structure 120 decrease. Can be. In addition, when the active layer 126 emits UV light including Al, the amount of light emitted to the side of the active layer 126 is increased compared to the GaN-based blue light emitting device (TM mode). This TM mode can occur mainly in ultraviolet semiconductor devices.

Ultraviolet semiconductor devices have poor current dissipation characteristics compared to blue GaN-based semiconductor devices. Accordingly, in the ultraviolet semiconductor device, it is necessary to dispose relatively many first electrodes 142 as compared to the blue GaN-based semiconductor device.

Increasing the composition of aluminum can deteriorate the current dispersion characteristics. Referring to FIG. 16A, current is distributed only to a nearby point of each first electrode 142, and a current density may be sharply lowered at a long distance. Therefore, the effective light emitting area P2 can be narrowed.

The effective emission area P2 may be defined as an area up to a boundary point having a current density of 40% or less based on the current density at the center of the first electrode 142 having the highest current density. For example, the effective light emitting region P2 may be adjusted according to the level of the injection current and the composition of Al within a range of 40 μm from the center of the recess 128.

The low current density region P3 may have a low current density and may emit less light than the effective light emitting region P2. Accordingly, the light output may be improved by further disposing the first electrode 142 in the low current density region P3 having a low current density or by using a reflective structure.

In general, a GaN-based semiconductor device emitting blue light has excellent current dispersing characteristics, and thus, it is preferable to minimize the area of the recess 128 and the first electrode 142. This is because the area of the active layer 126 decreases as the area of the recess 128 and the first electrode 142 increases. However, in the embodiment, since the composition of aluminum is high and current dispersal characteristics are relatively low, even if the area of the active layer 126 is sacrificed, the area and / or the number of the first electrodes 142 are increased so that the low current density region P3 is increased. It may be desirable to reduce or reduce the number of reflection structures in the low current density region P3.

Referring to FIG. 16B, when the number of the recesses 128 is increased to 48, the recesses 128 may be disposed in a zigzag fashion without being disposed in a straight line in the horizontal and vertical directions. In this case, since the area of the low current density region P3 can be narrowed, most of the active layer 126 can participate in light emission.

In the ultraviolet light emitting device, a current spreading characteristic may be degraded in the semiconductor structure 120, and a smooth current is obtained to secure electrical and optical characteristics and reliability of the semiconductor device by securing a uniform current density characteristic in the semiconductor structure 120. Injection is required. Accordingly, the first electrode 142 may be disposed by forming a larger number of recesses 128 than the general GaN-based semiconductor structure 120 for smooth current injection.

Referring to FIG. 17, the first insulating layer 131 may electrically insulate the first electrode 142 from the active layer 126 and the second conductive semiconductor layer 127. In addition, the first insulating layer 131 may electrically insulate the second electrode 146 and the second conductive layer 150 from the first conductive layer 165. In addition, the first insulating layer 131 may function to prevent side surfaces of the active layer 126 from being oxidized during the process of the semiconductor device.

The first insulating layer 131 may be formed by selecting at least one selected from the group consisting of SiO ₂ , SixOy, Si ₃ N ₄ , SixNy, SiOxNy, Al ₂ O ₃ , TiO ₂ , AlN, and the like, but is not limited thereto. . The first insulating layer 131 may be formed in a single layer or multiple layers. For example, the first insulating layer 131 may be a distributed Bragg reflector (DBR) having a multilayer structure including silver Si oxide or a Ti compound. However, the present invention is not limited thereto, and the first insulating layer 131 may include various reflective structures.

When the first insulating layer 131 performs the reflection function, the light extraction efficiency may be improved by reflecting the light L1 emitted toward the side from the active layer 126 upward. In this case, as the number of recesses 128 increases, the light extraction efficiency may be more effective.

The diameter W3 of the first electrode 142 may be 24 μm or more and 50 μm or less. If this range is satisfied, it may be advantageous for current dispersion, and a large number of first electrodes 142 may be disposed. When the diameter W3 of the first electrode 142 is greater than or equal to 24 µm, a sufficient amount of current injected into the first conductivity type semiconductor layer 124 can be ensured, and when the diameter is less than or equal to 50 µm, the first conductivity type semiconductor layer The number of the plurality of first electrodes 142 disposed in the area of 124 can be sufficiently secured and the current dispersion characteristic can be secured.

The diameter W1 of the recess 128 may be 38 µm or more and 60 µm or less. The diameter W1 of the recess 128 may be disposed under the second conductivity type semiconductor layer 127 to define the largest area of the recess 128. The diameter W1 of the recess 128 may be a diameter of the recess 128 disposed on the bottom surface of the second conductive semiconductor layer 127.

When the diameter W1 of the recess 128 is 38 µm or more, in forming the first electrode 142 disposed inside the recess 128, the first electrode 142 is of the first conductivity type. A process margin for securing an area for electrically connecting with the semiconductor layer 124 may be secured, and when the thickness is 60 μm or less, the volume of the active layer 126 that is reduced to dispose the first electrode 142 may be prevented. And the luminous efficiency may therefore deteriorate.

The inclination angle θ5 of the recess 128 may be 70 degrees to 90 degrees. If the area range is satisfied, it may be advantageous to form the first electrode 142 on the upper surface, and a large number of recesses 128 may be formed.

When the inclination angle θ5 is smaller than 70 degrees, the area of the active layer 126 removed may increase, but the area in which the first electrode 142 is disposed may be smaller. Therefore, the current injection characteristic can be lowered, and the luminous efficiency can be lowered. Therefore, the area ratio of the first electrode 142 and the second electrode 146 may be adjusted by using the inclination angle θ5 of the recess 128.

The thickness of the second electrode 146 may be thinner than the thickness of the first insulating layer 131. Therefore, the step coverage characteristics of the second conductive layer 150 and the second insulating layer 132 surrounding the second electrode 146 can be ensured, and the reliability of the semiconductor device can be improved. The second electrode 146 may have a first separation distance S1 of 1 μm to 4 μm from the first insulating layer 131. When the separation distance is 1 μm or more, the process margin of the process of disposing the second electrode 146 between the first insulating layers 131 can be ensured, thereby improving the electrical characteristics, optical characteristics, and reliability of the semiconductor device. Can be. When the separation distance is 4 μm or less, the entire area in which the second electrode 146 may be disposed may be secured, and operating voltage characteristics of the semiconductor device may be improved.

The second conductive layer 150 may cover the second electrode 146. Accordingly, the second electrode pad 166, the second conductive layer 150, and the second electrode 146 may form one electrical channel.

The second conductive layer 150 completely surrounds the second electrode 146 and may be in contact with the side surface and the top surface of the first insulating layer 131. The second conductive layer 150 is made of a material having good adhesion to the first insulating layer 131, and at least one material selected from the group consisting of materials such as Cr, Al, Ti, Ni, Au, and the like. It may be made of an alloy, and may be made of a single layer or a plurality of layers.

When the second conductive layer 150 is in contact with the side surface and the bottom surface of the first insulating layer 131, the thermal and electrical reliability of the second electrode 146 may be improved. The second conductive layer 150 may extend below the first insulating layer 131. In this case, the phenomenon that the end of the first insulating layer 131 is lifted up can be suppressed. Thus, penetration of external moisture or contaminants can be prevented. In addition, it may have a reflection function for reflecting light emitted between the first insulating layer 131 and the second electrode 146 to the top.

The second conductive layer 150 may be disposed at a first separation distance S1 between the first insulating layer 131 and the second electrode 146. The second conductive layer 150 may contact the side and top surfaces of the second electrode 146 and the side and top surfaces of the first insulating layer 131 at the first separation distance S1. In addition, a region where the second conductive layer 150 and the second conductive semiconductor layer 126 contact each other to form a Schottky junction within the first separation distance S1 may be disposed, and a current may be formed by forming a Schottky junction. Dispersion can be facilitated. However, the present invention is not limited thereto, and the resistance between the second conductive layer 150 and the second conductive semiconductor layer 127 is higher than the resistance between the second electrode 146 and the second conductive semiconductor layer 127. It can be arranged freely within this larger configuration.

The second insulating layer 132 may electrically insulate the second electrode 146 and the second conductive layer 150 from the first conductive layer 165. The first conductive layer 165 may be electrically connected to the first electrode 142 through the second insulating layer 132. The second insulating layer 132 and the first insulating layer 131 may be formed of the same material or may be formed of different materials.

According to an embodiment, the second insulating layer 132 is disposed on the first insulating layer 131 in the region between the first electrode 142 and the second electrode 146, so that the first insulating layer 131 is defective. In this case, the penetration of external moisture and / or other contaminants can be prevented.

For example, when the first insulating layer 131 and the second insulating layer 132 are formed of one layer, defects such as cracks may easily propagate in the thickness direction. Therefore, external moisture or contaminants may penetrate into the semiconductor structure through defects exposed to the outside.

However, according to the embodiment, since a separate second insulating layer 132 is disposed on the first insulating layer 131, defects formed in the first insulating layer 131 are difficult to propagate to the second insulating layer 132. . That is, the interface between the first insulating layer 131 and the second insulating layer 132 may serve to shield the propagation of defects.

Referring to FIG. 15 again, the second conductive layer 150 may electrically connect the second electrode 146 and the second electrode pad 166.

The second electrode 146 may be directly disposed on the second conductivity type semiconductor layer 127. When the second conductivity-type semiconductor layer 127 is AlGaN, hole injection may not be smooth due to low electrical conductivity. Therefore, it is necessary to appropriately adjust the Al composition of the second conductivity type semiconductor layer 127. This will be described later.

The second conductive layer 150 may be made of at least one material selected from the group consisting of materials such as Cr, Al, Ti, Ni, Au, and alloys thereof, and may be made of a single layer or a plurality of layers. .

The first conductive layer 165 and the bonding layer 160 may be disposed along the shape of the bottom surface and the recess 128 of the semiconductor structure 120. The first conductive layer 165 may be made of a material having excellent reflectance. In exemplary embodiments, the first conductive layer 165 may include aluminum. When the electrode layer 165 includes aluminum, the light emitting efficiency may be improved by reflecting light emitted from the active layer 126 toward the substrate 170. However, the present invention is not limited thereto, and the first conductive layer 165 may provide a function for electrically connecting the first electrode 142. The first conductive layer 165 may be disposed without a material having high reflectivity, for example, aluminum and / or silver (Ag), in which case the first electrode 142 disposed in the recess 128. ) And a reflective metal layer (not shown) made of a material having high reflectance may be disposed between the first conductive layer 165 and the second conductive semiconductor layer 127 and the first conductive layer 165. .

The bonding layer 160 may comprise a conductive material. For example, the bonding layer 160 may include a material selected from the group consisting of gold, tin, indium, aluminum, silicon, silver, nickel, and copper, or an alloy thereof.

The substrate 170 may be made of a conductive material. In exemplary embodiments, the substrate 170 may include a metal or a semiconductor material. The substrate 170 may be a metal having excellent electrical conductivity and / or thermal conductivity. In this case, heat generated during the operation of the semiconductor device may be quickly released to the outside. In addition, when the substrate 170 is made of a conductive material, the first electrode 142 may receive a current from the outside through the substrate 170.

The substrate 170 may include a material selected from the group consisting of silicon, molybdenum, silicon, tungsten, copper, and aluminum, or an alloy thereof.

The passivation layer 180 may be disposed on the top and side surfaces of the semiconductor structure 120. The passivation layer 180 may have a thickness of 200 nm or more and 500 nm or less. When it is 200 nm or more, the device may be protected from external moisture or foreign matter, thereby improving the electrical and optical reliability of the device. When it is less than 500 nm, the stress applied to the semiconductor device may be reduced, and the optical and electrical reliability of the semiconductor device may be reduced. In addition, as the processing time of the semiconductor device increases, the problem that the cost of the semiconductor device increases.

Unevenness may be formed on the upper surface of the semiconductor structure 120. Such unevenness may improve extraction efficiency of light emitted from the semiconductor structure 120. The unevenness may have a different average height according to the ultraviolet wavelength, and in the case of UV-C, the light extraction efficiency may be improved when the UV-C has a height of about 300 nm to 800 nm and an average of about 500 nm to 600 nm.

18 is a conceptual diagram of a semiconductor device according to another embodiment of the present invention, and FIG. 19 is a plan view of FIG. 18.

Referring to FIG. 18, the above-described configuration of the semiconductor structure 120 may be applied as it is. In addition, the plurality of recesses 128 may pass through the second conductivity-type semiconductor layer 127 and the active layer 126 to be disposed to a portion of the first conductivity-type semiconductor layer 124.

The semiconductor device may include a side reflector Z1 disposed at an edge thereof. The side reflector Z1 may be formed by protruding the second conductive layer 150, the first conductive layer 165, and the substrate 170 in a thickness direction (Y-axis direction). Referring to FIG. 20, the side reflector Z1 may be disposed along an edge of the semiconductor device to surround the semiconductor structure 120.

The second conductive layer 150 of the side reflector Z1 may protrude higher than the active layer 126 to reflect upwardly the light emitted from the active layer 126. Therefore, the light emitted in the horizontal direction (X-axis direction) can be upwardly reflected by the TM mode at the outermost part without forming a separate reflective layer.

An inclination angle of the side reflector Z1 may be greater than 90 degrees and smaller than 145 degrees. The inclination angle may be an angle between the second conductive layer 150 and the horizontal plane (XZ plane). When the angle is smaller than 90 degrees or larger than 145 degrees, the efficiency of reflecting light moving toward the side upwards may be inferior.

20 is a conceptual diagram of a semiconductor device package according to an embodiment of the present invention, FIG. 21 is a plan view of a semiconductor device package according to an embodiment of the present invention, FIG. 22 is a modification of FIG. 21, and FIG. 23 is shown. A cross-sectional view of a semiconductor device package according to another embodiment of the invention.

Referring to FIG. 20, the semiconductor device package may include a body 2 having grooves (openings 3), a semiconductor device 1 disposed on the body 2, and a body 2 disposed on the body 2. It may include a pair of lead frames (5a, 5b) that are electrically connected. The semiconductor device 1 may include all of the above configurations.

The body 2 may include a material or a coating layer that reflects ultraviolet light. The body 2 may be formed by stacking a plurality of

layers

2a, 2b, 2c, 2d, and 2e. The plurality of

layers

2a, 2b, 2c, 2d, and 2e may be the same material or may include different materials. For example, the plurality of

layers

2a, 2b, 2c, 2d, and 2e may include an aluminum material.

The groove 3 may be wider as it is farther from the semiconductor device, and a step 3a may be formed on the inclined surface.

The light transmitting layer 4 may cover the groove 3. The light transmitting layer 4 may be made of glass, but is not limited thereto. The light transmitting layer 4 is not particularly limited as long as it is a material that can effectively transmit ultraviolet light. The inside of the groove 3 may be an empty space.

Referring to FIG. 21, the semiconductor device 10 may be disposed on the first lead frame 5a and connected to the second lead frame 5b by a wire. In this case, the second lead frame 5b may be disposed to surround side surfaces of the first lead frame.

Referring to FIG. 22, a plurality of

semiconductor devices

10a, 10b, 10c, and 10d may be disposed in the semiconductor device package. In this case, the lead frame may include first to

fifth lead frames

5a, 5b, 5c, 5d, and 5e.

The first semiconductor element 10a may be disposed on the first lead frame 5a and connected to the second lead frame 5b by a wire. The second semiconductor device 10b may be disposed on the second lead frame 5b and connected to the third lead frame 5c by wires. The third semiconductor device 10c may be disposed on the third lead frame 5c and connected to the fourth lead frame 5d by a wire. The fourth semiconductor device 10d may be disposed on the fourth lead frame 5d and may be connected to the fifth lead frame 5e by a wire.

Referring to FIG. 23, a semiconductor device package may include a body 10 including a cavity 11, a semiconductor device 100 disposed inside the cavity 11, and a light transmitting member 50 disposed on the cavity 11. ) May be included.

The body 10 may be manufactured by processing an aluminum substrate. Therefore, both the inner and outer surfaces of the body 10 according to the embodiment may have conductivity. Such a structure can have various advantages. In the case of using a non-conductive material such as AlN and Al ₂ O ₃ as the body 10, since the reflectance of the ultraviolet wavelength band is only 20% to 40%, there is a problem in that a separate reflective member must be disposed. In addition, a separate conductive member such as a lead frame and a circuit pattern may be required. As a result, manufacturing costs may rise and the process may become complicated. In addition, a conductive member such as gold (Au) has a problem in that light absorption efficiency is reduced by absorbing ultraviolet rays.

However, according to the embodiment, since the body 10 itself is made of aluminum, a high reflectance in the ultraviolet wavelength band can be omitted a separate reflection member. In addition, since the body 10 itself is conductive, separate circuit patterns and lead frames may be omitted. In addition, since it is made of aluminum, the thermal conductivity may be excellent as 140W / m.k to 160W / m.k. Therefore, the heat dissipation efficiency can also be improved.

The body 10 may include a first conductive portion 10a and a second conductive portion 10b. The first insulating portion 42 may be disposed between the first conductive portion 10a and the second conductive portion 10b. Since both of the first conductive portion 10a and the second conductive portion 10b are conductive, the first insulating portion 42 needs to be disposed to separate the poles.

The body 10 may include a groove 14 disposed at an edge where the lower surface 12 and the side surface 13 meet, and a second insulating portion 41 disposed on the groove 14. The groove 14 may be disposed entirely along the edge where the lower surface 12 and the side surface 13 meet.

The second insulation portion 41 may be made of the same material as the first insulation portion 42 but is not necessarily limited thereto. The first insulating portion 42 and the second insulating portion 41 may be modified by EMC, white silicone, PSR (Photoimageable Solder Resist), silicone resin composition, modified epoxy resin composition such as silicone modified epoxy resin, epoxy modified silicone resin, or the like. Silicone resin composition, polyimide resin composition, modified polyimide resin composition, polyphthalamide (PPA), polycarbonate resin, polyphenylene sulfide (PPS), liquid crystal polymer (LCP), ABS resin, phenol resin, acrylic resin, PBT Resins such as resins and the like can be selected.

According to the embodiment, since the second insulating portion 41 is disposed at the lower edge of the body 10, burrs may be prevented from occurring at the edges when cutting the package. In the case of an aluminum substrate, burrs may be generated relatively compared to other metal substrates. If a burr occurs, the lower surface 12 may not be flat, and thus the mounting may be poor. In addition, when a burr occurs, the thickness may become uneven, and measurement errors may occur.

The third insulation portion 43 may be disposed on the bottom surface 12 of the body 10 and may be connected to the second insulation portion 41 and the first insulation portion 42. According to the embodiment, the lower surface 12 of the body, the lower surface of the second insulating portion 41, and the lower surface of the third insulating portion 43 may be disposed on the same plane.

24 is a conceptual diagram of a light emitting structure according to an embodiment of the present invention, Figure 25 is a graph showing the aluminum composition of the light emitting structure according to an embodiment of the present invention.

Referring to FIG. 24, a semiconductor device according to the embodiment includes a light emitting structure 120A including a first conductive semiconductor layer 124, a second conductive semiconductor layer 127, and an active layer 126. Each semiconductor layer may have the same structure as described with reference to FIG. 1.

Referring to FIG. 25, the first conductive semiconductor layer, the active layer 126, the blocking layer 129, and the second conductive semiconductor layer 127 may all include aluminum.

Therefore, the first conductive semiconductor layer 124, the active layer 126, the blocking layer 129, and the second conductive semiconductor layer 127 may be AlGaN. However, it is not necessarily limited thereto. Some layers may be GaN or AlN.

In the active layer 126, a plurality of well layers 126a and a barrier layer 126b may be alternately disposed. The well layer 126a may have an aluminum composition of about 30% to 50% to emit ultraviolet light. Barrier layer 126b may have an aluminum composition of 50% to 70% to confine the carrier.

For example, the well layer closest to the blocking layer 129 among the well layers 126a may be defined as the first well layer 126a and the last barrier disposed between the first well layer 126a and the blocking layer 129. The layer is defined as the first barrier layer 126b.

The blocking layer 129 may have an aluminum composition of 50% to 90%. The blocking layer 129 may alternately include a plurality of first blocking layers 129d having a relatively high aluminum composition and a plurality of second blocking layers 129e having a low aluminum composition. When the aluminum composition of the blocking layer 129 is less than 50%, the height of the energy barrier for blocking electrons may be insufficient, and the light emitted from the active layer 126 may be absorbed by the blocking layer 129, and the aluminum composition may be 90%. Exceeding the% may deteriorate the electrical characteristics of the semiconductor device.

The aluminum composition of the first blocking layer 129d may be 70% to 90%, and the aluminum composition of the second blocking layer 129e may be 50% to 70%. However, the present invention is not limited thereto, and the aluminum composition of the first blocking layer 129d and the second blocking layer 129e may be adjusted according to the purpose.

The first intermediate layer S10 may be disposed between the first well layer 126a and the blocking layer 129 of the active layer 126. The first intermediate layer S10 may include a third-first section S11 having a lower aluminum composition than the blocking layer 129, and a third-second section S12 having a higher aluminum composition than the blocking layer 129. .

The first intermediate layer S10 may be a first barrier layer 126b. Therefore, the thickness of the first intermediate layer S10 may be the same as the thickness of the neighboring barrier layer 126b. For example, the thickness of the first intermediate layer S10 may be 2 nm to 10 nm. However, the present disclosure is not limited thereto, and the first intermediate layer S10 may be a separate semiconductor layer disposed between the first barrier layer 126b and the blocking layer 129 or may be part of the blocking layer 129.

The aluminum composition of the third section 1 (S11) may be 50% to 70%. That is, the third-first section S11 may be substantially the same as the aluminum composition of the adjacent barrier layer 126b. The thickness of the third-first section S11 may be about 1 nm to 8 nm. When the thickness of the third section S11 is less than or equal to 1 nm, it may be difficult to prevent a problem of crystallinity deterioration caused by a sharp increase in Al content in the well layer 126a. In addition, when the thickness of the third section S11 is thicker than 8 nm, the hole injection efficiency into the active layer 126 may be lowered, thereby lowering optical characteristics.

The third-second section S12 may have a higher aluminum composition than the blocking layer 129. As the closer to the blocking layer 129, the third-second section S12 may have a higher aluminum composition. The aluminum composition of the second to third sections S12 may be 80% to 100%. That is, the third-second section S12 may be AlGaN or AlN. Alternatively, the third-second section S12 may be a superlattice layer in which AlGaN and AlN are alternately arranged.

The third-second section S12 may be thinner than the third-first section S11. The thickness of the third-second section S12 may be about 0.1 nm to 4 nm. If the thickness of the third section S12 is thinner than 0.1 nm, there may be a problem in that the movement of electrons may not be efficiently blocked. In addition, when the thickness of the third section S12 is thicker than 4 nm, there may be a problem in that the efficiency of injecting holes into the active layer is reduced.

The thickness ratio of the third-first section S11 and the third-second section S12 may be 10: 1 to 1: 1. When the above conditions are satisfied, the electron movement may be blocked while the hole injection efficiency may not be reduced.

The third-second section S12 may include an undoped section. Although the third-second section S12 grows without supplying the dopant, Mg of the blocking layer 129 may be diffused in a portion of the first section. However, at least a portion of the third-second section S12 may include an undoped section to prevent the dopant from diffusing into the active layer 126.

FIG. 26 is a graph showing an aluminum composition of a light emitting structure according to another embodiment of the present invention, FIG. 27 is a graph measuring light output of a semiconductor device including a conventional light emitting structure, and FIG. 28 is a view showing another embodiment of the present invention. It is a graph measuring the light output of the light emitting structure according to.

Referring to FIG. 26, all of the structures described with reference to FIG. 25 may be applied except for the configuration of the second intermediate layer S20. The second intermediate layer S20 may be part of the blocking layer 129, but is not necessarily limited thereto.

The aluminum composition of the second intermediate layer S20 may be lower than that of the blocking layer 129 and higher than the aluminum composition of the third-first section S11. For example, the aluminum composition of the second intermediate layer S20 may be 50% to 80%.

The second intermediate layer S20 may include a fourth-first section S21 that does not include a P-type dopant, and a fourth-second section S22 that includes a P-type dopant.

The fourth-first section S21 may be an undoped section. Therefore, it is possible to suppress diffusion of the dopant into the active layer 126 when the blocking layer 129 is grown. The thickness of the fourth section S21 may be 4 nm to 19 nm. When the thickness of the fourth-first section S21 is smaller than 4 nm, it is difficult to suppress diffusion of the dopant, and when the thickness is larger than 19 nm, the hole injection efficiency may be reduced.

The fourth-second section S22 may include a P-type dopant. The 4-2 section S22 may include the dopant to improve the efficiency in which holes are injected into the 4-1 section S21. That is, the fourth section S22 may serve as a low resistance layer that lowers the resistance level.

The thickness of the fourth section S22 may be 1 nm to 6 nm. When the thickness is smaller than 1 nm, it is difficult to effectively lower the resistance, and when the thickness is larger than 6 nm, the thickness of the 4-1 section S21 may be reduced, which may make it difficult to suppress diffusion of the dopant. The ratio of the thickness of the fourth-first section S21 and the thickness of the fourth-second section S22 may be 19: 1 to 1: 1.5.

However, the present invention is not limited thereto, and the second intermediate layer S20 may have a superlattice structure in which the fourth-first section S21 and the fourth-second section S22 are alternately arranged.

Referring to FIG. 27, it can be seen that in the case of a semiconductor device having a conventional light emitting structure, the light output decreases by 20% after about 100 hours increase. It can also be seen that after about 500 hours, the light output is reduced by about 25%.

On the contrary, referring to FIG. 28, in the case of the semiconductor device having the light emitting structure according to the embodiment, the luminous intensity of about 3.5% was reduced even after 100 hours, and the light output was about the same even after about 500 hours. It can be confirmed. That is, it can be seen that the embodiment has about 20% improved light output compared to the diameter of the conventional structure without the intermediate layer.

29 is a graph showing an aluminum composition of a light emitting structure according to another embodiment of the present invention.

Referring to FIG. 29, the second conductive semiconductor layer 129 may include a 2-1 conductive semiconductor layer 129a and a 2-2 conductive semiconductor layer 129b.

The thickness of the second-first conductive semiconductor layer 127a may be larger than 10 nm and smaller than 200 nm. When the thickness of the second-first conductive semiconductor layer 127a is smaller than 10 nm, the resistance may increase in the horizontal direction, thereby lowering the current injection efficiency. In addition, when the thickness of the second-first conductive semiconductor layer 127a is greater than 200 nm, the resistance may increase in the vertical direction, thereby lowering the current injection efficiency.

The aluminum composition of the second-first conductive semiconductor layer 127a may be higher than that of the well layer 126a. The aluminum composition of the well layer 126a may be about 30% to 50% to generate ultraviolet light. If the aluminum composition of the 2-1 conductive semiconductor layer 127a is lower than that of the well layer 126a, the light extraction efficiency may decrease because the 2-1 conductive semiconductor layer 127a absorbs light. Can be.

The aluminum composition of the second-first conductive semiconductor layer 127a may be greater than 40% and less than 80%. If the aluminum composition of the second-first conductive semiconductor layer 127a is less than 40%, there is a problem of absorbing light, and if greater than 80%, the current injection efficiency is deteriorated. For example, when the aluminum composition of the well layer 126a is 30%, the aluminum composition of the 2-1 conductive semiconductor layer 127a may be 40%.

The aluminum composition of the second-second conductive semiconductor layer 127a may be lower than that of the well layer 126a. If the aluminum composition of the second-conductive semiconductor layer 127a is higher than that of the well layer 126a, the resistance between the p-omic electrodes is increased, so that sufficient ohmic is not achieved and current injection efficiency is inferior. .

The aluminum composition of the second-second conductive semiconductor layer 127a may be greater than 1% and less than 50%. If it is larger than 50%, a sufficient ohmic may not be achieved with the p-omic electrode. If the composition is smaller than 1%, there is a problem of absorbing light because it is almost close to the GaN composition.

The thickness of the second-2 conductive semiconductor layer 127a may be greater than 1 nm and smaller than 30 nm. As described above, the second conductive semiconductor layer 127a may absorb ultraviolet light because the composition of aluminum is low for ohmic. Therefore, it may be advantageous in terms of light output to control the thickness of the second-second conductive semiconductor layer 127a as thin as possible.

However, when the thickness of the second-second conductive semiconductor layer 127a is controlled to 1 nm or less, the second-second conductive semiconductor layer 127a is not disposed in some sections, and the second-first conductive semiconductor layer 127a is not disposed. ) May be exposed to the outside of the light emitting structure 120. In addition, when the thickness is larger than 30 nm, the amount of light to be absorbed may be too large to reduce the light output efficiency.

The second-second conductive semiconductor layer 127a may further include a first sub layer 127e and a second sub layer 127d. The first sub layer 127e may be a surface layer in contact with the second electrode, and the second sub layer 127d may be a layer for adjusting the composition of aluminum.

The first sub layer 127e may have an aluminum composition of greater than 1% and less than 20%. Or the aluminum composition may be greater than 1% and less than 10%.

If the aluminum composition is lower than 1%, there may be a problem that the light absorption rate is too high in the first sub layer 127e. If the aluminum composition is higher than 20%, the contact resistance of the second electrode (p-omic electrode) is increased. There may be a problem that the current injection efficiency is low.

However, the present invention is not limited thereto, and the aluminum composition of the first sub layer 127e may be adjusted in consideration of the current injection characteristic and the light absorption rate. Alternatively, it can be adjusted according to the light output required by the product.

For example, when the current injection efficiency characteristic is more important than the light absorption rate, the composition ratio of aluminum can be adjusted to 1% to 10%. In the case of products in which light output characteristics are more important than electrical characteristics, the aluminum composition ratio of the first sub layer 127e may be adjusted to 1% to 20%.

When the aluminum composition ratio of the first sub layer 127e is greater than 1% and less than 20%, the resistance between the first sub layer 127e and the second electrode decreases, thereby lowering the operating voltage. Thus, the electrical characteristics can be improved. The thickness of the first sub layer 127e may be greater than 1 nm and smaller than 10 nm. Therefore, the problem of light absorption can be improved.

The thickness of the second-second conductive semiconductor layer 127a may be smaller than the thickness of the second-first conductive semiconductor layer 127a. The thickness ratio of the 2-1 conductive semiconductor layer 127a and the 2-2 conductive semiconductor layer 127a may be 1.5: 1 to 20: 1. When the thickness ratio is smaller than 1.5: 1, the thickness of the 2-1 conductive semiconductor layer 127a may be too thin, thereby reducing current injection efficiency. In addition, when the thickness ratio is greater than 20: 1, the thickness of the second conductive semiconductor layer 127a may be too thin, thereby reducing ohmic reliability.

The aluminum composition of the second-first conductive semiconductor layer 127a may be smaller as it moves away from the active layer 126. In addition, the aluminum composition of the second-second conductive semiconductor layer 127a may be smaller as it moves away from the active layer 126. Therefore, the aluminum composition of the first sub layer 127e may satisfy 1% to 10%.

However, the present invention is not necessarily limited thereto, and the aluminum compositions of the 2-1 conductive semiconductor layer 127a and the 2-2 conductive semiconductor layer 127a do not continuously decrease, but include a section in which there is no decrease in a certain section. You may.

In this case, an aluminum reduction width of the second conductive semiconductor layer 127a may be greater than an aluminum reduction width of the second conductive semiconductor layer 127a. That is, the change rate in the thickness direction of the Al composition ratio of the 2-2 conductive semiconductor layer 127a may be greater than the change rate in the thickness direction of the Al composition ratio of the 2-1 conductive semiconductor layer 127a. The thickness direction may be a direction from the first conductive semiconductor layer 124 to the second conductive semiconductor layer 127 or a direction from the second conductive semiconductor layer 127 to the first conductive semiconductor layer 124. Can be.

While the thickness of the 2-1 conductive semiconductor layer 127a is thicker than that of the 2-2 conductive semiconductor layer 127a, the aluminum composition should be higher than that of the well layer 126a, so that the decrease may be relatively slow.

However, since the thickness of the second-2 conductive semiconductor layer 127a is large and the variation of the aluminum composition is large, the reduction of the aluminum composition may be relatively large.

FIG. 30 is a conceptual diagram of a light emitting structure grown on a substrate, FIG. 31 is a view for explaining a process of separating a substrate, FIG. 32 is a view for explaining a process of etching a light emitting structure, and FIG. 33 is a manufactured semiconductor. A diagram showing the device.

Referring to FIG. 30, a buffer layer 122, a light absorbing layer 123, a first conductive semiconductor layer 124, an active layer 126, a second conductive semiconductor layer 127, and a second substrate are formed on the growth substrate 121. The second electrode 246 and the second conductive layer 150 may be sequentially formed.

In this case, a first intermediate layer and a second intermediate layer may be grown between the active layer 126 and the blocking layer 129. The first barrier layer may be grown to have a 1-1 section having an aluminum composition of 50% to 70% and a 1-2 section having an aluminum composition of 80% to 100%. In addition, the second intermediate layer may be grown to have a second-first section doped with the P-type dopant and a second-second section doped with the dopant.

The light absorption layer 123 includes a first light absorption layer 123a having a low aluminum composition and a second light absorption layer 123b having a high aluminum composition. A plurality of first light absorbing layers 123a and second light absorbing layers 123b may be alternately disposed.

The aluminum composition of the first light absorption layer 123a may be lower than that of the first conductive semiconductor layer 124. The first light absorption layer 123a may serve to absorb and separate the laser during the LLO process. Thus, the growth substrate can be removed.

The thickness of the first light absorbing layer 123a and the aluminum composition may be appropriately adjusted to absorb a laser having a wavelength (eg, 246 nm). The aluminum composition of the first light absorption layer 123a may be 20% to 50%, and the thickness may be 1 nm to 10 nm. For example, the first light absorption layer 123a may be AlGaN, but is not limited thereto.

The aluminum composition of the second light absorption layer 123b may be higher than that of the first conductive semiconductor layer 124. The second light absorption layer 123b may improve the crystallinity of the first conductive semiconductor layer 124 grown on the light absorption layer 123 by increasing the aluminum composition lowered by the first light absorption layer 123a.

For example, the aluminum composition of the second light absorption layer 123b may be 60% to 100%, and the thickness may be 0.1 nm to 2.0 nm. The second light absorption layer 123b may be AlGaN or AlN.

In order to absorb a laser having a wavelength of 246 nm, the thickness of the first light absorption layer 123a may be thicker than the thickness of the second light absorption layer 123b. The thickness of the first light absorbing layer 123a may be 1 nm to 10 nm, and the thickness of the second light absorbing layer 123b may be 0.5 nm to 2.0 nm.

The thickness ratio of the first light absorbing layer 123a and the second light absorbing layer 123b may be 2: 1 to 6: 1. When the thickness ratio is smaller than 2: 1, the first light absorption layer 123a is thinner, so that it is difficult to absorb the laser sufficiently. When the thickness ratio is larger than 6: 1, the second light absorption layer 123b is too thin, so that the total aluminum composition of the light absorption layer is low. There is a problem.

The overall thickness of the light absorption layer 123 may be larger than 100 nm and smaller than 400 nm. If the thickness is less than 100 nm, the thickness of the first light absorption layer 123a becomes thin, and thus, it is difficult to sufficiently absorb the 246 nm laser. If the thickness is larger than 400 nm, the aluminum composition is lowered as a whole, thereby deteriorating crystallinity.

According to an embodiment, the light absorption layer 123 having a superlattice structure may be formed to improve crystallinity. In this configuration, the light absorption layer 123 may function as a buffer layer to mitigate lattice mismatch between the growth substrate 121 and the light emitting structure 120.

Referring to FIG. 31, in the removing of the growth substrate 121, the growth substrate 121 may be separated by irradiating the laser L1 from the growth substrate 121. The laser L1 may have a wavelength band that the first light absorption layer 123a can absorb. As an example, the laser may be a KrF laser having a wavelength range of 248 nm.

The growth substrate 121 and the second light absorption layer 123b do not absorb the laser L1 due to the large energy band gap. However, the first light absorption layer 123a having a low aluminum composition may be decomposed by absorbing the laser L1. Therefore, it may be separated together with the growth substrate 121.

Thereafter, the light absorption layer 123-2 remaining in the first conductive semiconductor layer 124 may be removed by leveling.

Referring to FIG. 32, after forming the second conductive layer 150 on the second conductive semiconductor layer 127, a recess penetrating to a part of the first conductive semiconductor layer 124 of the light emitting structure 120 ( A plurality of 128) can be formed. Thereafter, the insulating layer 130 may be formed on the side surface of the recess 128 and the second conductive semiconductor layer 127. Thereafter, the first electrode 142 may be formed in the first conductive semiconductor layer 124b exposed by the recess 128.

Referring to FIG. 33, the first conductive layer 165 may be formed under the insulating layer 130. The first conductive layer 165 may be electrically insulated from the second conductive layer 150 by the insulating layer 130.

Subsequently, the conductive substrate 170 may be formed below the first conductive layer 165, and the second electrode pad 166 may be formed on the second conductive layer 150 exposed by mesa etching.

The semiconductor device can be applied to various kinds of light source devices. For example, the light source device may be a concept including a sterilizing device, a curing device, a lighting device, and a display device and a vehicle lamp. That is, the semiconductor device may be applied to various electronic devices disposed in a case to provide light.

The sterilization apparatus may include a semiconductor device according to the embodiment to sterilize a desired region. The sterilizer may be applied to household appliances such as water purifiers, air conditioners and refrigerators, but is not necessarily limited thereto. That is, the sterilization apparatus can be applied to all the various products (eg, medical devices) requiring sterilization.

Illustratively, the water purifier may be provided with a sterilizing device according to the embodiment to sterilize the circulating water. The sterilization apparatus may be disposed at a nozzle or a discharge port through which water circulates to irradiate ultraviolet rays. At this time, the sterilization apparatus may include a waterproof structure.

The curing apparatus includes a semiconductor device according to an embodiment to cure various kinds of liquids. Liquids can be the broadest concept that includes all of the various materials that cure when irradiated with ultraviolet light. By way of example, the curing apparatus may cure various kinds of resins. Alternatively, the curing device may be applied to cure a cosmetic product such as a nail polish.

The lighting apparatus may include a light source module including a substrate and the semiconductor device of the embodiment, a heat dissipation unit for dissipating heat of the light source module, and a power supply unit for processing or converting an electrical signal provided from the outside and providing the light source module to the light source module. In addition, the lighting apparatus may include a lamp, a head lamp, or a street lamp.

The display device may include a bottom cover, a reflector, a light emitting module, a light guide plate, an optical sheet, a display panel, an image signal output circuit, and a color filter. The bottom cover, the reflector, the light emitting module, the light guide plate, and the optical sheet may constitute a backlight unit.

The reflecting plate is disposed on the bottom cover, and the light emitting module may emit light. The light guide plate may be disposed in front of the reflective plate to guide light emitted from the light emitting module to the front, and the optical sheet may include a prism sheet or the like to be disposed in front of the light guide plate. The display panel is disposed in front of the optical sheet, the image signal output circuit supplies an image signal to the display panel, and the color filter may be disposed in front of the display panel.

The semiconductor device may be used as an edge type backlight unit or a direct type backlight unit when used as a backlight unit of a display device.

The semiconductor element may be a laser diode in addition to the light emitting diode described above.

Like the light emitting device, the laser diode may include the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer having the above-described structure. In addition, although the p-type first conductive semiconductor and the n-type second conductive semiconductor are bonded to each other, an electro-luminescence phenomenon is used in which light is emitted when a current flows, but the direction of emitted light is used. There is a difference in and phase. That is, a laser diode may emit light having a specific wavelength (monochromatic beam) in the same direction with the same phase by using a phenomenon called stimulated emission and a constructive interference phenomenon. Due to this, it can be used for optical communication, medical equipment and semiconductor processing equipment.

For example, a photodetector may be a photodetector, which is a type of transducer that detects light and converts its intensity into an electrical signal. Such photodetectors include photovoltaic cells (silicon, selenium), photoelectric devices (cadmium sulfide, cadmium selenide), photodiodes (e.g. PD having peak wavelength in visible blind or true blind spectral regions) Transistors, photomultipliers, phototubes (vacuum, gas encapsulation), infrared (Infra-Red) detectors, and the like, but embodiments are not limited thereto.

In addition, a semiconductor device such as a photodetector may generally be manufactured using a direct bandgap semiconductor having excellent light conversion efficiency. Alternatively, the photodetector has various structures, and the most common structures include a pin photodetector using a pn junction, a Schottky photodetector using a Schottky junction, a metal semiconductor metal (MSM) photodetector, and the like. have.

Like a light emitting device, a photodiode may include a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer having the above-described structure, and have a pn junction or pin structure. The photodiode operates by applying a reverse bias or zero bias. When light is incident on the photodiode, electrons and holes are generated and current flows. In this case, the magnitude of the current may be approximately proportional to the intensity of light incident on the photodiode.

Photovoltaic cells or solar cells are a type of photodiodes that can convert light into electrical current. The solar cell may include the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer having the above-described structure, similarly to the light emitting device.

In addition, through the rectification characteristics of a general diode using a p-n junction it may be used as a rectifier of an electronic circuit, it may be applied to an ultra-high frequency circuit and an oscillation circuit.

In addition, the semiconductor device described above is not necessarily implemented as a semiconductor and may further include a metal material in some cases. For example, a semiconductor device such as a light receiving device may be implemented using at least one of Ag, Al, Au, In, Ga, N, Zn, Se, P, or As, and may be implemented by a p-type or n-type dopant. It may also be implemented using a doped semiconductor material or an intrinsic semiconductor material.

Although the above description has been made based on the embodiments, these are merely examples and are not intended to limit the present invention. Those skilled in the art to which the present invention pertains may not have been exemplified above without departing from the essential characteristics of the present embodiments. It will be appreciated that many variations and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

Claims

A light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer;

A first electrode electrically connected to the first conductive semiconductor layer; And

A second electrode electrically connected to the second conductivity type semiconductor layer,

The second conductivity type semiconductor layer includes a first surface on which the second electrode is disposed,

The second conductivity type semiconductor layer has a ratio (W2: W1) of a second shortest distance W2 from the first surface to a second point and a first shortest distance W1 from the first surface to the first point. Is 1: 1.25 to 1: 100,

The first point is a point having the same composition as the aluminum composition of the well layer closest to the second conductivity type semiconductor layer among the active layers,

And the second point is a point at which the aluminum composition and the dopant composition of the second conductive semiconductor layer are the same.
The method of claim 1,

The ratio of the second shortest distance and the first shortest distance is 1: 1.25 to 1:10.
The method of claim 1,

An electron blocking layer disposed between the active layer and the second conductivity type semiconductor layer,

The ratio of the first difference between the average aluminum composition of the electron blocking layer and the aluminum composition at the first point and the second difference between the average aluminum composition of the electron blocking layer and the aluminum composition at the second point is from 1: 1.2. A semiconductor device of 1:10.
The method of claim 1,

The second conductivity type semiconductor layer,

A 2-1 conductive semiconductor layer, and a 2-2 conductive semiconductor layer disposed between the active layer and the 2-1 conductive semiconductor layer,

The second conductive semiconductor layer includes a second conductive semiconductor layer disposed between the active layer and the second conductive semiconductor layer.
The method of claim 4, wherein

The aluminum composition of the 2-1 conductivity type semiconductor layer and the 2-2 conductivity type semiconductor layer decreases as it moves away from the active layer,

The aluminum reduction width of the 2-1 conductivity type semiconductor layer is greater than the aluminum reduction width of the 2-2 conductivity type semiconductor layer.
A light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer;

A first electrode electrically connected to the first conductive semiconductor layer; And

A second electrode electrically connected to the second conductivity type semiconductor layer,

The second conductivity type semiconductor layer includes a first surface on which the second electrode is disposed,

The second conductivity type semiconductor layer has a ratio (W2: W1) of a second shortest distance W2 from the first surface to a second point and a first shortest distance W1 from the first surface to the first point. Is 1: 1.25 to 1: 100,

The first point is a point having the same composition as the aluminum composition of the well layer closest to the second conductivity type semiconductor layer among the active layers,

The aluminum composition of the second point is smaller than the aluminum composition of the first point,

The aluminum composition of the second point is 5% to 55% of the semiconductor device.
The method of claim 6,

The ratio of the first shortest distance and the second shortest distance is 1: 1.25 to 1:10.
The method of claim 6,

An electron blocking layer disposed between the active layer and the second conductivity type semiconductor layer,

The ratio of the first difference between the average aluminum composition of the electron blocking layer and the aluminum composition at the first point and the second difference between the average aluminum composition of the electron blocking layer and the aluminum composition at the second point is from 1: 1.2. A semiconductor device of 1:10.
The method of claim 1,

The second conductivity type semiconductor layer,

A 2-1 conductive semiconductor layer, and a 2-2 conductive semiconductor layer disposed between the active layer and the 2-1 conductive semiconductor layer,

The second conductive semiconductor layer includes a second conductive semiconductor layer disposed between the active layer and the second conductive semiconductor layer.
Body; And

A semiconductor device disposed in the body,

The semiconductor device,

A light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer;

A first electrode electrically connected to the first conductive semiconductor layer; And

A second electrode electrically connected to the second conductivity type semiconductor layer,

The second conductivity type semiconductor layer includes a first surface on which the second electrode is disposed,

The second conductivity type semiconductor layer has a ratio (W2: W1) of a second shortest distance W2 from the first surface to a second point and a first shortest distance W1 from the first surface to the first point. Is 1: 1.25 to 1: 100,

The first point is a point having the same composition as the aluminum composition of the well layer closest to the second conductivity type semiconductor layer among the active layers,

The second point is a semiconductor device package is a point where the aluminum composition and the dopant composition of the second conductivity-type semiconductor layer is the same.