KR102533221B1 - Semiconductor device and semiconductor device package including the same - Google Patents

Abstract

The embodiment includes a semiconductor structure including a first conductivity-type semiconductor layer, a second conductivity-type semiconductor layer, and an active layer disposed between the first conductivity-type semiconductor layer and the second conductivity-type semiconductor layer; a first electrode electrically connected to the first conductivity type semiconductor layer; and a second electrode electrically connected to the second conductivity-type semiconductor layer, wherein the second conductivity-type semiconductor layer includes a first point having the highest aluminum composition and a second point having the lowest aluminum composition in the semiconductor structure. three points, wherein the first conductivity-type semiconductor layer includes a second point having the highest aluminum composition and a fourth point having the lowest aluminum composition within the first conductivity-type semiconductor layer; The ratio of the aluminum composition between the first points is 1:4 to 1:100, and the ratio of the aluminum composition between the fourth point and the second point is 1:0.5 to 1:0.9, and a semiconductor device including the same Disclose the device package.

Description

Semiconductor device and semiconductor device package including the same

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

Semiconductor devices including compounds such as GaN and AlGaN have many advantages, such as having a wide and easily adjustable band gap energy, and can be used in various ways such as light emitting devices, light receiving devices, and various diodes.

In particular, light emitting devices such as light emitting diodes or laser diodes using group 3-5 or group 2-6 compound semiconductor materials of semiconductors are developed in thin film growth technology and device materials to produce red, green, Various colors such as blue and ultraviolet can be realized, and white light with high efficiency can be realized by using fluorescent materials or combining colors. , safety, and environmental friendliness.

In addition, when light receiving devices such as photodetectors or solar cells are manufactured using group 3-5 or group 2-6 compound semiconductor materials, photocurrent is generated by absorbing light in various wavelength ranges through the development of device materials. By doing so, it is possible to use light in a wide range of wavelengths from gamma rays to radio wavelengths. In addition, it has the advantages of fast response speed, safety, environmental friendliness, and easy control of element materials, so that it can be easily used in power control or ultra-high frequency circuits or communication modules.

Accordingly, the semiconductor device can replace a transmission module of an optical communication means, a light emitting diode backlight that replaces a Cold Cathode Fluorescence Lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, and can replace a fluorescent lamp or an incandescent bulb. Applications are expanding to white light emitting diode lighting devices, automobile headlights and traffic lights, and sensors that detect gas or fire. In addition, applications of semiconductor devices can be expanded to high-frequency application circuits, other power control devices, and communication modules.

In particular, a light emitting element that emits light in the ultraviolet wavelength region can be used for curing, medical, and sterilization purposes by performing a curing or sterilizing action.

Recently, research on UV light emitting devices has been actively conducted, but it is still difficult to implement UV light emitting devices in a vertical type, and when a GaN thin film is used for ohmic characteristics, there is a problem in that light output decreases.

An embodiment provides a semiconductor device with improved light output.

In addition, a semiconductor device having improved ohmic characteristics is provided.

In addition, a vertical ultraviolet light emitting device is provided.

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

A semiconductor device according to an embodiment includes a semiconductor structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; a first electrode electrically connected to the first conductivity type semiconductor layer; and a second electrode electrically connected to the second conductivity-type semiconductor layer, wherein the second conductivity-type semiconductor layer includes a first point having the highest aluminum composition and a second point having the lowest aluminum composition in the semiconductor structure. three points, wherein the first conductivity-type semiconductor layer includes a second point having the highest aluminum composition and a fourth point having the lowest aluminum composition within the first conductivity-type semiconductor layer; The aluminum composition ratio between the first points is 1:4 to 1:100, and the aluminum composition ratio between the fourth point and the second point is 1:0.5 to 1:0.9.

According to the embodiment, light output may be improved by suppressing light absorption in the semiconductor device.

In addition, resistance between the second conductivity type semiconductor layer and the second electrode can be reduced without the GaN thin film.

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

1 is a conceptual diagram of a semiconductor structure according to an embodiment of the present invention;
Figure 2 is a graph showing the aluminum composition ratio of the semiconductor structure according to an embodiment of the present invention,
3a and 3b are SIMS (SIMS) data of a semiconductor structure according to an embodiment of the present invention,
3c and 3d are SIMS data of a semiconductor structure according to another embodiment of the present invention,
4 is a diagram showing the aluminum ion strength of FIGS. 3A to 3D;
5A is a partially enlarged view of SIMS data of FIG. 4(a);
5B is a diagram showing SIMS data of FIG. 4(b) converted to a linear scale;
6A is a conceptual diagram of a second conductivity type semiconductor layer according to an embodiment of the present invention;
6B is AFM data obtained by measuring the surface of a second conductivity type semiconductor layer according to an embodiment of the present invention;
6c is AFM data obtained by measuring the surface of a GaN thin film;
6D is AFM data obtained by measuring the surface of the second conductivity-type semiconductor layer grown at high speed;
7 is a conceptual diagram of a semiconductor device according to an embodiment of the present invention;
8A and 8B are views for explaining a configuration in which light output is improved according to a change in the number of recesses;
9 is an enlarged view of part A of FIG. 7;
10 is a conceptual diagram of a semiconductor device according to another embodiment of the present invention;
11 is a plan view of FIG. 10;
12 is a conceptual diagram of a semiconductor device package according to an embodiment of the present invention;
13 is a plan view of a semiconductor device package according to an embodiment of the present invention;
14 is a modified example of FIG. 13;
15 is a cross-sectional view of a semiconductor device package according to another embodiment of the present invention.

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

Even if a matter described in a specific embodiment is not described in another embodiment, it may be understood as a description related to another embodiment, unless there is a description contrary to or contradictory to the matter in another embodiment.

For example, if the characteristics of component A are described in a specific embodiment and the characteristics of component B are described in another embodiment, the opposite or contradictory description even if the embodiment in which components A and B are combined is not explicitly described. Unless there is, it should be understood as belonging to the scope of the present invention.

In the description of the embodiment, in the case where an element is described as being formed “on or under” of another element, on or under (on or under) or under) includes both elements formed by directly contacting each other or by indirectly placing one or more other elements between the two elements. In addition, when expressed as "on or under", it may include the meaning of not only the upward direction but also the downward direction based on one element.

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

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

Referring to FIGS. 1 and 2 , a semiconductor device according to an embodiment includes a first conductivity type semiconductor layer 124, a second conductivity type semiconductor layer 127, and a first conductivity type semiconductor layer 124 and a second conductivity type semiconductor layer. and a semiconductor structure 120 including an active layer 126 disposed between type semiconductor layers 127 .

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

Illustratively, the light (UV-A) in the near ultraviolet wavelength range may have a wavelength ranging from 320 nm to 420 nm, and the light (UV-B) in the far ultraviolet wavelength range may have a wavelength ranging from 280 nm to 320 nm. The light (UV-C) of the wavelength range may have a wavelength ranging from 100 nm to 280 nm.

When the semiconductor structure 120 emits light in the ultraviolet wavelength range, each semiconductor layer of the semiconductor structure 120 contains aluminum In _x1 Al _y1 Ga _1-x1-y1 N (0≤x1≤1, 0<y1 ≤1, 0≤x1+y1≤1) may include a material. Here, the composition of Al can be represented by the ratio of the total atomic weight including the atomic weight of In, the atomic weight of Ga, and the atomic weight of Al to the atomic weight of Al. For example, when the Al composition is 40%, the Ga composition may be 60% Al ₄₀ Ga ₆₀ N.

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

The first conductivity-type semiconductor layer 124 may be implemented with a compound semiconductor such as group III-V or group II-VI, and may be doped with a first dopant. The first conductivity-type 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), eg For example, it may be selected from AlGaN, AlN, InAlGaN, and the like. Also, 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 conductivity-type semiconductor layer 124 doped with the first dopant may be an n-type semiconductor layer. However, the first conductivity-type semiconductor layer 124 is not limited thereto and may be a p-type semiconductor layer.

The first conductivity type semiconductor layer 124 includes the 1-1 conductivity type semiconductor layer 124a, the 1-2 conductivity type semiconductor layer 124c, and the 1-1 conductivity type semiconductor layer 124a and the 1-1 conductivity type semiconductor layer 124a. An intermediate layer 124b disposed between the two conductive semiconductor layers 124c may be included.

The aluminum composition of the 1-1st conductivity type semiconductor layer 124a may be 50% to 80%. When the aluminum composition of the 1-1 conductivity type semiconductor layer 124a is 50% or more, the light extraction efficiency can be improved by lowering the absorbance of deep ultraviolet light (UV-C) emitted from the active layer 126. % or less, current injection characteristics into the active layer 126 and current diffusion characteristics in the 1-1st conductivity type semiconductor layer 124a may be secured.

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

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

When the aluminum composition of the 1-2 conductive semiconductor layer 124c is 40% or more, the light extraction efficiency can be improved by lowering the absorbance of deep ultraviolet light (UV-C) emitted from the active layer 126. % or less, current injection characteristics into the active layer 126 and current diffusion characteristics in the first-second conductivity type semiconductor layer 124c may be secured.

The aluminum composition of the 1-1st conductivity type semiconductor layer 124a and the 1-2nd conductivity type 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 of light having a wavelength in the ultraviolet region may be lowered within the semiconductor structure 120 .

In addition, when the aluminum composition of the 1-1 conductivity type semiconductor layer 124a is higher than the aluminum composition of the 1-2 conductivity type semiconductor layer 124c, the semiconductor structure 120 is formed in the active layer 126 due to the difference in refractive index. It may be more advantageous to extract light to the outside. Accordingly, light extraction efficiency of the semiconductor structure 120 may be improved.

The thickness of the 1-2th conductivity type semiconductor layer 124c may be smaller than that of the 1-1st conductivity type semiconductor layer 124a. The thickness of the 1-1st conductivity type semiconductor layer 124a may be 130% or more of the thickness of the 1-2nd conductivity type semiconductor layer 124c. According to this configuration, since the intermediate layer 124b is disposed after sufficiently securing the thickness of the 1-1 conductivity type semiconductor layer 124a having a high aluminum composition, the crystallinity of the entire semiconductor structure 120 can be improved.

The aluminum composition of the intermediate layer 124b may be lower than the aluminum composition of the first conductivity type semiconductor layer 124 and the second conductivity type semiconductor layer 124 . The intermediate layer 124b may serve to prevent the active layer 126 from being damaged by absorbing laser irradiated onto the semiconductor structure 120 during a laser lift-off (LLO) process of removing the growth substrate. Accordingly, the semiconductor device according to the embodiment can prevent damage to the active layer 126 during a laser lift-off (LLO) process, so that light output and electrical characteristics can be improved.

In addition, in order to secure current injection efficiency by lowering the resistance between the intermediate layer 124b and the first electrode when the intermediate layer 124b is in contact with the first electrode, the aluminum composition of the intermediate layer 124b is the 1-1 conductivity type semiconductor layer. (124a), it may be lower than the aluminum composition of the first-second conductivity type semiconductor layer (124c).

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

When the laser for 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 aluminum composition of the intermediate layer 124b may be increased to correspond to the LLO laser wavelength. Illustratively, the aluminum composition of the intermediate layer 124b may be as high as 50% to 70%.

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

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

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. In the well layer 126a, first carriers (electrons or holes) injected through the first conductivity type semiconductor layer 124 and second carriers (holes or electrons) injected through the second conductivity type semiconductor layer 127 are formed. layer that meets When the first carrier (or second carrier) of the conduction band and the second carrier (or first carrier) of the valence band recombine in the well layer 126a of the active layer 126, the conduction band of the well layer 126a and the well layer ( Light having a wavelength corresponding to the difference in energy level (energy band gap) of the valence band of 126a) may be generated.

The active layer 126 may have a structure of 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 wire structure, and the active layer 126 The structure of is not limited to this.

The active layer 126 may include a plurality of well layers 126a and a plurality of barrier layers 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 aluminum composition of the well layer 126a may vary according to the emission wavelength.

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

The second conductive semiconductor layer 127 is a semiconductor material having a composition formula of In _x5 Al _y2 Ga _1-x5-y2 N (0≤x5≤1, 0<y2≤1, 0≤x5+y2≤1) or AlInN , AlGaAs, GaP, GaAs, GaAsP, may be formed of a material selected from AlGaInP.

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

The second conductivity type semiconductor layer 127 may include the 2-1st to 2-3th conductivity type semiconductor layers 127a, 127b, and 127c. The 2-1st conductivity type semiconductor layer 127a may have a smaller aluminum composition than the 2-2nd conductivity type semiconductor layer 127b and the 2-3rd 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, so that electrons and holes recombine in the active layer 126. You can increase your chances of doing it. An energy bandgap of the blocking layer 129 may be larger than that of the active layer 126 and/or the second conductive semiconductor layer 127 . Since the blocking layer 129 is doped with the second dopant, it may be defined as a partial region of the second conductivity type semiconductor layer 127 .

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, It may be selected from AlN, InAlGaN, etc., but is not limited thereto.

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

The aluminum composition of the blocking layer 129 may be higher than that of the well layer 126a. Illustratively, the aluminum composition of the blocking layer 129 may be 50% to 100%. When 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 1-1 section 129a and a 1-2 section 129c.

In the 1-1 th section 129a, the aluminum composition may increase in a direction from the first conductivity type semiconductor layer 124 to the second conductivity type semiconductor layer 127.

The aluminum composition of the 1-1 section 129a may be 80% to 100%. Accordingly, the 1-1 th section 129a of the blocking layer 129 may be a portion having the highest Al composition in the semiconductor structure 120 .

The 1-1 section 129a may include AlGaN or AlN. Alternatively, the 1-1 section 129a may be a superlattice layer in which AlGaN and AlN are alternately disposed.

The thickness of the 1-1st section 129a may be about 0.1 nm to about 4 nm. In order to efficiently block the movement of the first carriers into the second conductivity type semiconductor layer 127, the thickness of the 1-1 section 129a may be greater than or equal to 0.1 nm. In addition, in order to secure injection efficiency of injecting second carriers from the second conductive semiconductor layer 127 into the active layer 126, the thickness of the 1-1 section 129a may be less than 4 nm.

In the 1-1 section 129a of the embodiment, the thickness of the 1-1 section 129-a is set to 0.1 nm or more to 4 nm or less in order to secure hole injection efficiency and electron blocking efficiency. Not limited. For example, if it is necessary to selectively secure any one of the first carrier blocking function and the second carrier injection function, the aforementioned numerical range may be exceeded.

The 1-3 section 129b disposed between the 1-1 section 129a and the 1-2 section 129c may include an undoped section containing no dopant. Accordingly, the first to third sections 129b may prevent diffusion of the second dopant from the second conductivity type semiconductor layer 127 to the active layer 126 .

The second conductivity type semiconductor layer 127 may include the 2-1st to 2-3th conductivity type semiconductor layers 127a, 127b, and 127c.

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

The aluminum composition of the 2-2 conductivity type semiconductor layer 127b may be higher than that of the well layer 126a. In order to generate ultraviolet light, the aluminum composition of the well layer 126a may be about 30% to 70%. Therefore, the aluminum composition of the 2-2 conductivity type semiconductor layer 127b may be 40% or more and 80% or less.

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

The aluminum composition of the 2-1 conductivity type semiconductor layer 127a may be lower than that of the well layer 126a. When the aluminum composition of the 2-1 conductivity type semiconductor layer 127a is higher than the aluminum composition of the well layer 126a, the resistance between the second electrodes increases, so that sufficient ohmic is not achieved and current injection efficiency is deteriorated.

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

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

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

The thickness of the 2-1st conductivity type semiconductor layer 127a may be smaller than the thickness of the 2-2nd conductivity type semiconductor layer 127b. The thickness ratio of the 2-1st conductivity type semiconductor layer 127a and the 2-2nd conductivity type semiconductor layer 127b may be 1:1.5 to 1:20. When the thickness ratio is greater than 1:1.5, since the thickness of the 2-2 conductivity type semiconductor layer 127b increases, current injection efficiency can be improved. In addition, when the thickness ratio is less than 1:20, the thickness of the 2-1st conductivity type semiconductor layer 127a increases, so that the problem of deterioration in crystallinity can be improved. If the thickness of the 2-1 conductivity type semiconductor layer 127a is too thin, the aluminum composition must be rapidly changed within the thickness range, and thus crystallinity may deteriorate.

The aluminum composition of the 2-2 conductivity type semiconductor layer 127b may decrease as the distance from the active layer 126 increases. In addition, the aluminum composition of the 2-1st conductivity type semiconductor layer 127a may decrease as the distance from the active layer 126 increases.

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

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

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

As a result, since the thickness of the 2-1st conductivity type semiconductor layer 127a is thin, but the change range of aluminum is relatively large, the reduction range of aluminum relative to the thickness may be relatively large.

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

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

The second-third conductivity type semiconductor layer 127c may have a uniform aluminum composition. The thickness of the second-third conductivity type semiconductor layer 127c may be 20 nm to 60 nm. The aluminum composition of the second-third conductivity type semiconductor layer 127c may be 40% to 70%. When the aluminum composition of the 2-3 conductivity type semiconductor layer 127c is 40% or more, the crystallinity of the 2-1 conductivity type semiconductor layer 127a and the 2-2 conductivity type semiconductor layer 127b may not deteriorate. When it is less than 70%, it is possible to prevent a problem of deterioration in crystallinity caused by abruptly changing the aluminum composition of the 2-1st conductivity type semiconductor layer 127a and the 2-2nd conductivity type semiconductor layer 127b. electrical properties can be improved.

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 is The thickness of (127c) may be 20 nm to 60 nm.

Accordingly, the ratio of the thickness of the 2-1st conductivity type semiconductor layer 127a to the total thickness of the second conductivity type semiconductor layer 127 may be 1:3 to 1:120. When the ratio is greater than 1:3, the 2-1 conductivity type semiconductor layer 127a can secure the electrical characteristics (eg, operating voltage) of the semiconductor device, and when the ratio is less than 1:120, the optical characteristics (eg, operating voltage) of the semiconductor element can be secured. For example, light output) can be secured. However, it is not necessarily limited thereto, and the ratio of the thickness of the 2-1 conductivity type semiconductor layer 127a to the total thickness of the second conductivity type semiconductor layer 127 is 1:3 to 1:50 or 1:3 to 1: may be 70

The second conductivity-type 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 1-1st section 129a of the blocking layer 129 having the highest aluminum composition, and the third point P3 is the 2-1st conductivity type semiconductor layer (with the lowest aluminum composition). 127a).

The first conductivity type semiconductor layer 124 may include a second point P2 having the highest aluminum composition and a fourth point P4 having the lowest aluminum composition within the first conductivity type semiconductor layer. The second point P2 may be the 1-1st conductivity type semiconductor layer 124a and/or the 1-2th conductivity type semiconductor layer 124c, and the fourth point P4 may be the intermediate layer 124b. .

The aluminum composition of the 1-1 section 129a may be 80% to 100%. The aluminum composition of the 2-1st conductivity type 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 the aluminum composition of the well layer 126a.

Accordingly, the aluminum composition ratio 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 at the first point P1 increases to effectively block the first carriers from passing through the second conductivity type semiconductor layer. In addition, when the ratio of the aluminum composition is 1:100 or less, the problem of light absorption at the third point P3 may be improved by increasing the amount of aluminum at the third point P3.

The aluminum composition of the 1-1st conductivity type 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 1-1 conductivity type semiconductor layer. Accordingly, 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 1:0.5 or more, the aluminum composition of the 1-1 conductivity type semiconductor layer 124a increases, and thus crystallinity may be improved. In addition, when the aluminum composition ratio is 1:0.9 or less, since the aluminum composition of the intermediate layer 124b is increased, the problem of absorbing light in the ultraviolet wavelength range can be improved.

3A and 3B are Secondary Ion Mass Spectrometry (SIMS) data of a semiconductor structure according to an embodiment of the present invention, and FIGS. 3C and 3D are SIMS (SIMS) data of a semiconductor structure according to another embodiment of the present invention. ) data, FIG. 4 is a diagram showing the aluminum relative ionic strength of FIGS. 3A to 3D, FIG. 5A is a partially enlarged view of the SIMS data of FIG. 4 (a), and FIG. It is a diagram in which SIMS data of is converted to linear scale.

Referring to Figure 3a, the semiconductor structure is aluminum (Al), gallium (Ga), the first dopant, the second dopant, oxygen ( O), the composition of carbon (C) can change. The first dopant may be silicon (Si) and the second dopant may be magnesium (Mg), but is not necessarily limited thereto.

SIMS data may be analysis data by Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS).

SIMS data can be analyzed by irradiating primary ions onto the surface of a target and counting the number of secondary ions emitted. At this time, the primary ion may be selected from O ₂ ⁺ , Cs ⁺ Bi ^{+ ,} etc., the accelerating voltage may be adjusted within 20 to 30 keV, the irradiation current may be adjusted at 0.1 pA to 5.0 pA, and the irradiation area may be 20 nm × 20 nm.

SIMS data may collect secondary ion mass spectra while gradually etching from the surface of the second conductivity type semiconductor layer (a point where the depth is 0) toward the first conductivity type semiconductor layer.

However, the measurement conditions for detecting the AlGaN-based and/or GaN-based semiconductor material and the first and second dopant materials may be variously used without being limited thereto.

In addition, the result of the SIMS analysis can be interpreted as a spectrum for the secondary ionic strength or doping concentration of the material, which may include noise occurring within 0.9 times or more to 1.1 times in the analysis of the secondary ionic strength or doping concentration. can Accordingly, the description of "equal/identical" may include noise within 0.9 times or more to 1.1 times of one particular secondary ionic strength or doping concentration.

On the SIMS data of FIGS. 3A to 3D , aluminum and gallium are spectral data for secondary ion intensities, and first dopant, second dopant, oxygen, and carbon are data obtained by measuring doping concentrations. That is, in FIGS. 3A to 3D , SIMS data and doping concentration data are expressed in one diagram.

Referring to FIG. 3A , although it is shown that the aluminum ion intensity spectrum and parts of the first and second dopant concentration spectra intersect, the ion intensity and dopant concentration data may have an independent relationship with each other.

Illustratively, it is expressed as the intersection of the ionic strength of aluminum and the doping concentration of the second dopant in the vicinity of the surface (the point where the depth is 0), but the reference point of the doping concentration (the lowest point on the left Y-axis of the drawing) is lower If set, the doping concentration graph on the data may be lowered. For example, if the reference point of the second dopant doping concentration is lowered from 1.00E+14 to 1.00E+12, the second dopant concentration graph becomes lower on the drawing, so the second dopant data and aluminum data may not intersect.

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

It can be seen that the ionic strength of aluminum gradually increases as the depth increases from the surface, and then increases and decreases repeatedly after the point of maximum strength. In a GaN-based semiconductor material, Al atoms replace Ga atoms to form an AlGaN material, so that the ionic strength of gallium and the ionic strength of aluminum can be symmetrical to each other.

The ionic strength according to the embodiment may be increased or decreased according to measurement conditions. However, when the intensity of the primary ion increases, the intensity graph of the secondary ion (aluminum ion) may increase as a whole, and when the intensity of the primary ion decreases, the intensity graph of the secondary ion (aluminum ion) may decrease as a whole. Therefore, the change in ionic strength in the thickness direction can 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 as the distance from the surface increases. The second dopant may be present in all regions of the second conductivity type semiconductor layer and in some regions of the active layer, but is not necessarily limited thereto. The second dopant may be disposed only in the second conductivity type semiconductor layer, but may diffuse to the active layer. Accordingly, injection efficiency of the second dopant implanted into the active layer may be improved. However, when the second dopant diffuses into the first conductivity-type semiconductor layer, leakage current of the semiconductor device and/or non-emissive 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 of the first dopant is lower than the concentration of oxygen in the section between the first conductivity type semiconductor layer and the active layer. The first dopant may also be partially distributed in the active layer. Accordingly, the injection efficiency of the first carrier injected into the active layer can be improved, and the efficiency of luminescent recombination between the first carrier and the second carrier in the active layer can be improved.

It can be seen that FIGS. 3B to 3D also show the same trend as FIG. 3A.

Referring to FIGS. 4 and 5A , the aluminum ion intensities of FIGS. 3A to 3D may include first to sixth points P1 , P2 , P3 , P4 , P5 , and P6 . Figure 4 (a) is the aluminum ion strength of Figure 3a, Figure 4 (b) is the aluminum ion strength of Figure 3b, Figure 4 (c) is the aluminum ion strength of Figure 3c, Figure 4 (d ) is the aluminum ion intensity in Fig. 3d.

In the embodiments of FIGS. 3C and 3D , the distribution of aluminum ion intensity is similar to that of FIG. 3A except that there is a concavo-convex section P7 in which the ionic strength changes between the first point P1 and the third point P3. may have a distribution. Illustratively, the embodiments of FIGS. 3C, 3D, 4C, and 4D 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 ionic strength of aluminum at the first point P1 is the highest, non-emissive recombination of the first carriers with the second carriers in the second conductive semiconductor layer can be prevented. Accordingly, light output of the semiconductor device can be improved. The first point P1 may be a region corresponding to the 1-1st section 129a of the blocking layer 129, but is not necessarily limited thereto.

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

The second point P2 may be a point where the ionic strength of aluminum is highest in the first conductivity type semiconductor layer 124 and may be a point closest to the active layer 126 in the first conductivity type semiconductor layer 124. there is.

At the second point P2 , first carrier energy injected from the first conductive semiconductor layer 124 toward the active layer may be lowered to balance concentrations or densities of first and second carriers recombinated in the active layer. Accordingly, light output characteristics of the semiconductor device may be improved by improving luminous efficiency.

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

When the third point P3 and the second electrode are in contact, since the ionic strength of aluminum at the third point P3 is the lowest, the resistance between the third point P3 and the second electrode may be low, and thus the second electrode Through this, 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 where the ionic strength of aluminum in the first direction at the second point P2 is the lowest.

The fourth point (P4) can prevent the active layer from being damaged by the LLO process by absorbing the laser so that the laser does not penetrate into the active layer when the Laser Lift-Off (LLO) process is applied during the semiconductor device process. there is.

In addition, when the first electrode contacts the fourth point P4, the injection efficiency of the current injected into the semiconductor structure can be improved by lowering the resistance between the first electrode and the fourth point P4. From this point of view, the ionic strength of aluminum at the fourth point P4 may be the 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 a specific point and constitute one layer. The current injected through the fourth point P4 can be uniformly distributed in the layer including the fifth point P5, so that the density of the current injected into the active layer can be improved to be uniform.

In addition, a point/layer having the same ionic strength of aluminum as the fifth point P5 may be spaced apart from the fourth point P4 in the first direction. Accordingly, the fourth point P4 may be disposed between the points/layers having the ionic strength of aluminum of the fifth point P5. However, it is not limited thereto, and the ionic strength of aluminum in a region farther from the fifth point P5 in the first direction than the fourth point P4 in the first direction has a higher ionic strength than the fifth point P5. can have

The tenth point (P10) may be disposed between the first point (P1) and the third point (P3), and between the first point (P1) and the second point (P2) of aluminum having the same minimum ionic strength. It can be a point with ionic strength.

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

Also, the third point P3 electrically connected to the second electrode may have 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 that of the fourth point P4.

Therefore, 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 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 region 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 decreases as it approaches the surface S0. It may have a reversal period (P6) in which is not reduced. The inversion period P6 may be a period in which the aluminum ion strength increases or is maintained as it approaches the surface S0.

When the reversal 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 evenly spread, so that the current density injected into the active layer can be evenly controlled. can Accordingly, light output characteristics, electrical characteristics, and reliability of the semiconductor device may be improved.

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

Therefore, in the process of continuously lowering and raising the temperature, as soon as the lowered temperature is raised again, a lot of aluminum is instantaneously included, thereby forming the reversal section P6.

That is, in the process from the formation of 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 to the formation of the third point (P3), the composition of aluminum is determined through temperature. In this process, the reversal section P6 may be disposed to secure crystallinity of the second conductivity-type semiconductor layer and current diffusion characteristics.

However, the present invention is not limited thereto, and in another embodiment, the ionic strength of aluminum continuously increases from the tenth point P10 to the third point P3 without having a reversal section P6 in order to further secure current injection characteristics. may be arranged to decrease.

Referring to FIG. 5A , the semiconductor structure on the aluminum ion strength graph may include a first section S1 , a second section S2 , and a third section S3 in a direction in which the depth increases.

The first section S1 may be disposed between the first point P1 and the third point P3 and may be formed of a second conductivity type semiconductor layer. The second section S2 may be disposed between the first point P1 and the second point P2 and may include 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 the 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 (increase in depth) on the drawing, It may be a point having an ionic strength higher than the maximum ionic strength (peak ionic strength) of the second period S2.

However, it is not necessarily 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. The valley S22 may be the ionic strength of the well layer, and the peak S21 may be the ionic strength of the barrier layer.

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

When the ionic strength ratio (M1) of aluminum between the valley (S22) and the first point (P1) is 1:0.4 or more, the second point between the first point (P1) and the third point (P3) disposed closer to the surface than the active layer. Crystallinity of the conductive semiconductor layer may be secured, and the probability of luminescent recombination in the active layer may be increased by preventing injection of first carriers into the second conductive semiconductor layer. Accordingly, light output characteristics of the semiconductor device may be improved.

In addition, when the ionic strength ratio M1 is 1:0.6 or less, the crystallinity of the second conductivity type semiconductor layer between the first point P1 and the third point P3 disposed closer to the surface than the active layer can be secured. .

When the ionic strength ratio (M2) of the valley (S22) and the peak (S21) is 1:0.5 or more, carriers escaping from the well layer included in the active layer to the first conductivity type semiconductor layer and/or the second conductivity type semiconductor layer The light output characteristics of the semiconductor device can be improved by effectively preventing the barrier layer and increasing the probability of luminescent recombination in the well layer.

In addition, when the ionic strength ratio (M2) is 1:0.75 or less, the stress caused by 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 luminescent recombination probability due to strain are reduced. can be improved

The ratio of these two ratios (M1:M2) may satisfy 1:0.3 to 1:0.8. Accordingly, 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 active layer is actually disposed.

The ionic strength of the third point P3 may be lower than the lowest ionic strength (ionic strength of the well layer) in the second period S2. At this time, the active layer may be included in the second section S2 and may be defined as a region between a valley P8 closest to the first point P1 and a valley P9 furthest from the first point P1. .

Also, the distance between the neighboring valleys S22 may be narrower than the distance 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 ionic strength of the surface region S11 may decrease in a direction opposite to the first direction D.

The ratio of the first intensity difference D1 between the second point P2 and the fourth point P4 and the second intensity difference D2 between the first point P1 and the third point P3 on the Sims data ( D1:D2) may be 1:1.5 to 1:2.5. When the intensity difference ratio (D1:D2) is 1:1.5 or more, the second intensity difference D2 increases, so that the aluminum composition of the first point P1 can be sufficiently lowered. Therefore, contact resistance with the second electrode can be reduced.

In addition, when the ratio of the intensity difference (D1:D2) is 1:2.5 or less, the aluminum composition is too low, and the light emitted from the active layer 126 is absorbed by the 2-1 conductivity type semiconductor layer 127a, resulting in optical characteristics of the semiconductor device. This degradation problem can be solved.

The ratio 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 (D3:D4) may be from 1:0.2 to 1:2 or from 1:0.2 to 1:1.

When the intensity difference ratio is 1:0.2 or more, the fourth intensity difference D4 is relatively large, so the aluminum composition can be sufficiently lowered. Thus, contact resistance with the second electrode can be reduced. In addition, when the composition difference is 1:2 or less, it is possible to improve the problem of crystallinity deterioration due to rapid change in aluminum composition within the thickness range of the 2-1st conductivity type semiconductor layer 127a. In addition, the problem that the aluminum composition is too low and the light emitted from the active layer 126 is absorbed by the 2-1 conductivity type semiconductor layer 127a can be improved.

A thin GaN layer may be inserted for ohmic contact between the second conductive semiconductor layer 127 and the electrode. In this case, since the GaN layer contacting the electrode does not contain aluminum, the ionic strength of the third point P3 is rapidly reduced. Therefore, the ratio (D1:D2) of the first intensity difference (D1) to the second intensity difference (D2) and the ratio (D3:D4) of the third intensity difference (D3) to the fourth intensity difference (D4) are described above. may be out of bounds.

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 difference is 1:0.5 or more, the intensity of the fifth point P5 increases, so that crystallinity can be improved and light extraction efficiency can be improved. In addition, when the intensity difference ratio is smaller than 1:0.8, lattice mismatch between the active layer 126 and the first conductivity-type semiconductor layer 124 can be alleviated.

The ionic strength ratio 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, the strength of the third point P3 is sufficiently low, thereby reducing the contact resistance with the second electrode. Further, when the ionic strength ratio between the third point P3 and the first point P1 is 1:4 or less, the aluminum strength at the third point P3 may be increased. Accordingly, the problem of absorbing light at the third point P3 can be improved.

The ionic 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 of the tenth point P10 and the first point P1 is 1:1.3 or more, the ionic strength of the first point P1 increases, effectively blocking the passage of the first carrier through the active layer. In addition, when the ionic strength ratio of the tenth point P10 and the first point P1 is 1:2.5 or less, the ionic strength of the tenth point P10 increases, so that the well layer can generate light in the ultraviolet wavelength range. .

The ionic strength ratio of the third point P3 and the fourth point P4 may be 1:1.1 to 1:2. When the ionic strength ratio of the third point P3 and the fourth point P4 is 1:1.1 or more, the ionic strength of the fourth point P4 increases, thereby reducing 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 is secured at the third point to reduce light absorption in the ultraviolet wavelength range.

The ionic strength ratio between the second point P2 and the first point P1 may be 1:1.1 to 1:2. When the ionic strength ratio of the second point P2 and the first point P1 is 1:1.1 or more, the ionic strength of the first point P1 increases, effectively blocking the passage of the first carrier through the active layer. In addition, when the ionic strength ratio between the second point P2 and the first point P1 is 1:2 or less, the concentration of the first carrier injected into the active layer and undergoing luminescent recombination may be balanced with the concentration of the second carrier. Therefore, the amount of light emitted by the semiconductor element can be increased.

The ionic 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, resistance between the fourth point P4 and the first electrode may be reduced. In addition, when the ionic strength ratio of the fourth point P4 and the second point P2 is 1:2.5 or less, the ionic strength of the fourth point P4 increases, thereby reducing the absorption rate of light in the ultraviolet wavelength band.

The ionic strength ratio between the fifth point P5 and the second point P2 may be 1:1.1 to 1:2.0. In the case of an embodiment, a semiconductor structure emitting deep ultraviolet rays may be composed of a GaN-based material containing a large amount of aluminum compared to a semiconductor structure emitting blue light. Accordingly, the ratio of the mobility of the first carrier to the mobility of the second carrier may be different from that of a 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 secured. In addition, when the ionic strength ratio of the fifth point P5 and the second point P2 is 1:2.0 or less, the ionic strength of the fifth point P5 increases and crystallinity may be improved.

The ionic 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 of the fourth point P4 and the fifth point P5 is 1:1.1 or more, the ionic strength of the fifth point P5 increases, so crystallinity can be improved. In addition, when the ionic strength ratio of the fourth point P4 and the fifth point P5 is 1:2.0 or less, the ionic strength of the fourth point P4 increases, thereby reducing the absorption rate of light in the ultraviolet wavelength band.

In FIGS. 4 and 5A, the aluminum ion intensity is expressed in a logarithmic scale, but is not necessarily limited thereto, and may be converted to a linear scale as shown in FIG. 5B.

According to the embodiment, since the third point P3 includes aluminum, it can be confirmed that the first point P1 and the third point P3 are substantially disposed within one order. An order may be a unit of level of ionic strength. For example, the first order may be 1.0 × 10 ¹ and the second order may be 1.0 × 10 ² . Also, each order may have 10 sub-levels. Exemplarily, the first sublevel of the first order is 1.0×10 ¹ , the second sublevel of the first order is 2.0×10 ¹ , The third sublevel of the first order may be 3.0×10 ¹ , the ninth sublevel of the first order may be 9.0×10 ¹ , and the tenth sublevel of the first order may be 1.0×10 ² . That is, the 10th sublevel of the first order may be the same as the first sublevel of the second order.

6A is a conceptual diagram of a second conductivity type semiconductor layer according to an embodiment of the present invention, FIG. 6B is AFM data obtained by measuring the surface of the second conductivity type semiconductor layer according to an embodiment of the present invention, and FIG. 6C is AFM data obtained by measuring the surface of a GaN thin film, and FIG. 6D is AFM data obtained by measuring the surface of a high-speed grown second conductivity type semiconductor layer.

Referring to FIG. 6A , the second conductivity type semiconductor layer 127 according to the embodiment may include 2-1st to 2-3th conductivity type semiconductor layers 127a, 127b, and 127c. The 2-1st conductivity type semiconductor layer 127a may be a contact layer contacting the second electrode. As for the characteristics of each layer, the above description may be applied as it is.

A surface of the 2-1st conductivity type 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 a lattice mismatch between aluminum (Al) and gallium (Ga).

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

Referring to FIG. 6B , a relatively bright dot-shaped cluster C1 can be seen 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 be generated in the form of a cluster C1 to increase the junction area. Therefore, electrical characteristics can be improved.

On the surface of the second conductive 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. 6B, 12 clusters C1 per unit area of 2 μm in width and height were observed. As for the cluster (C1), only the cluster protruding more than 25 nm from the surface was measured. In the AFM image, the contrast can be adjusted so that only clusters protruding more than 25 nm from the surface are output.

The density of the cluster C1 whose unit is converted 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 smaller than 1×10 ⁻⁸ /cm ² , the contact area may be relatively reduced, thereby increasing contact resistance with the second electrode.

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 of the clusters, and thus light output may decrease.

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

Referring to FIG. 6C , it can be seen that no clusters are observed on the surface of the GaN thin film. This may be because the density of clusters increases to form one layer. Therefore, in the case of forming the GaN thin film between the second conductivity-type semiconductor layer and the second electrode, it can be seen that clusters are not formed on the contact surface.

Referring to FIG. 6D , it can be seen that clusters do not grow well even when the second conductivity type semiconductor layer is rapidly grown. Therefore, it can be seen that the cluster C1 is not formed when the growth rate is fast even when the composition of aluminum is controlled to be 1% to 10% on the surface of the second conductivity type semiconductor layer. Illustratively, FIG. 6D is a photograph of a surface measured after growing P-AlGaN at a rate of 0.06 nm/s.

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

In an embodiment, the growth rate of the 2-1 conductivity type semiconductor layer may be slower than the growth rates of the 2-2 and 2-3 conductivity type semiconductor layers. For example, the ratio of the growth rate of the 2-2nd conductivity type semiconductor layer to the growth rate of the 2-1st conductivity type semiconductor layer may be 1:0.2 to 1:0.8. When the growth rate ratio is less than 1:0.2, the growth rate of the 2-1 conductivity type semiconductor layer is too slow, and Ga is etched at a high temperature at which AlGaN is grown, and AlGaN with a high Al composition is grown, resulting in deterioration in ohmic characteristics. However, when the growth rate ratio is greater than 1:0.8, the growth rate of the 2-1st conductivity type semiconductor layer is too fast, and thus crystallinity may deteriorate.

7 is a conceptual diagram of a semiconductor device according to an exemplary embodiment, FIGS. 8A and 8B are diagrams for explaining a configuration in which light output is improved according to a change in the number of recesses, and FIG. This is a partial enlargement.

Referring to FIG. 7 , a semiconductor device according to an embodiment includes a semiconductor structure 120 including a first conductivity type semiconductor layer 124, a second conductivity type semiconductor layer 127, and an active layer 126, and a first conductivity type semiconductor layer 124. A first electrode 142 electrically connected to the type semiconductor layer 124 and a second electrode 146 electrically connected to the second conductivity type semiconductor layer 127 are included.

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

All of the above-described structures may be applied to the semiconductor structure 120 according to the embodiment. The semiconductor structure 120 may include a plurality of recesses 128 penetrating the second conductivity type semiconductor layer 127 and the active layer 126 and extending to a partial region of the first conductivity type semiconductor layer 124. .

The first electrode 142 may be disposed on an upper surface of the recess 128 and electrically connected to the first conductive semiconductor layer 124 . The second electrode 146 may be disposed under the second conductivity type 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 include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), 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, It may be formed including at least one of Ru, Mg, Zn, Pt, Au, and Hf, but is not limited to these materials. Illustratively, the first electrode may have a plurality of metal layers (eg, Cr/Al/Ni), and the second electrode may be ITO.

Referring to FIG. 8A, when the GaN-based semiconductor structure 120 emits ultraviolet light, aluminum may be included, and when the aluminum composition of the semiconductor structure 120 increases, current dissipation characteristics within the semiconductor structure 120 deteriorate. It can be. In addition, when the active layer 126 contains Al and emits ultraviolet rays, the active layer 126 emits more light to the side than a GaN-based blue light emitting device (TM mode). This TM mode may mainly occur in an ultraviolet semiconductor device.

UV semiconductor devices have poor current dissipation characteristics compared to blue GaN-based semiconductor devices. Therefore, the UV semiconductor device needs to dispose a relatively large number of first electrodes 142 compared to blue GaN-based semiconductor devices.

When the composition of aluminum is increased, current dissipation characteristics may be deteriorated. Referring to FIG. 8A , current is distributed only to points near each first electrode 142, and current density may rapidly decrease at points far away from each other. Accordingly, the effective light emitting region P2 may be narrowed.

The effective light emitting region P2 may be defined as an area up to a boundary point where the current density is 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 .

Since the current density of the low current density region P3 is low, the amount of emitted light may be smaller than that of the effective light emitting region P2. Accordingly, 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, since a GaN-based semiconductor device emitting blue light has relatively excellent current dissipation characteristics, 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 case of the embodiment, since the composition of aluminum is high and the current dissipation characteristic is relatively low, even if the area of the active layer 126 is sacrificed, the area and/or number of the first electrodes 142 are increased to form a low current density region P3. It may be desirable to reduce or place a reflective structure in the low current density region P3.

Referring to FIG. 8B , when the number of recesses 128 increases to 48, the recesses 128 may not be arranged in a straight line in the horizontal and vertical directions, but may be arranged in a zigzag pattern. 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 UV light emitting device, current spreading characteristics may be deteriorated within the semiconductor structure 120, and smooth current to ensure uniform current density characteristics within the semiconductor structure 120 to secure electrical and optical characteristics and reliability of the semiconductor device. need an infusion Therefore, for smooth current injection, the first electrode 142 may be disposed by forming a relatively large number of recesses 128 compared to the general GaN-based semiconductor structure 120 .

Referring to FIG. 9 , the first insulating layer 131 may electrically insulate the first electrode 142 from the active layer 126 and the second conductive semiconductor layer 127 . Also, 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 oxidation of the side surface of the active layer 126 during the process of the semiconductor device.

The first insulating layer 131 may be formed by selecting at least one 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 as a single layer or multiple layers. For example, the first insulating layer 131 may be a multi-layer distributed Bragg reflector (DBR) including silver Si oxide or a Ti compound. However, the first insulating layer 131 is not necessarily limited thereto and may include various reflective structures.

When the first insulating layer 131 performs a reflective function, light L1 emitted from the active layer 126 toward the side surface may be upwardly reflected to improve light extraction efficiency. In this case, as the number of recesses 128 increases, light extraction efficiency may be more effective.

The diameter W3 of the first electrode 142 may be greater than or equal to 24 μm and less than or equal to 50 μm. When this range is satisfied, current distribution may be advantageous, and a large number of first electrodes 142 may be disposed. When the diameter W3 of the first electrode 142 is greater than 24 μm, the current injected into the first conductivity-type semiconductor layer 124 can be sufficiently secured, and when the diameter W3 is less than 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 current dissipation characteristics can be secured.

The diameter W1 of the recess 128 may be greater than or equal to 38 μm and less than or equal to 60 μm. The diameter W1 of the recess 128 may be defined as the widest area of the recess disposed below the second conductivity type semiconductor layer 127 . The diameter W1 of the recess 128 may be the diameter of the recess 128 disposed on the bottom surface of the second conductivity type semiconductor layer 127 .

When the diameter W1 of the recess 128 is greater than or equal to 38 μm, in forming the first electrode 142 disposed inside the recess 128, the first electrode 142 is of the first conductivity type. It is possible to secure a process margin for securing an area to be electrically connected to the semiconductor layer 124, and to prevent the volume of the active layer 126 from decreasing to dispose the first electrode 142 when it is 60 μm or less. and thus the luminous efficiency may be deteriorated.

The inclination angle θ5 of the recess 128 may be 70 degrees to 90 degrees. When this 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 less than 70 degrees, the area of the active layer 126 to be removed may increase, but the area where the first electrode 142 is disposed may decrease. Accordingly, current injection characteristics may deteriorate and luminous efficiency may decrease. Accordingly, the area ratio of the first electrode 142 and the second electrode 146 may be adjusted using the inclination angle θ5 of the recess 128 .

A thickness of the second electrode 146 may be smaller than a thickness of the first insulating layer 131 . Accordingly, step coverage characteristics of the second conductive layer 150 and the second insulating layer 132 surrounding the second electrode 146 may be secured, and reliability of the semiconductor device may be improved. The second electrode 146 may have a first separation distance S1 from the first insulating layer 131 of 1 μm to 4 μm. When the separation distance is greater than or equal to 1 μm, a process margin of the process of disposing the second electrode 146 between the first insulating layers 131 can be secured, and thus the electrical characteristics, optical characteristics, and reliability of the semiconductor device are improved. It can be. When the separation distance is 4 μm or less, the entire area in which the second electrode 146 can be disposed can be secured and operating voltage characteristics of the semiconductor device can 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 contact the side surface and 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 contacts the side and bottom surfaces of the first insulating layer 131, the thermal and electrical reliability of the second electrode 146 can be improved. The second conductive layer 150 may extend below the first insulating layer 131 . In this case, lifting of the ends of the first insulating layer 131 can be suppressed. Therefore, penetration of external moisture or contaminants can be prevented. In addition, it may have a reflective function of reflecting light emitted between the first insulating layer 131 and the second electrode 146 upward.

The second conductive layer 150 may be disposed at the first separation distance S1 between the first insulating layer 131 and the second electrode 146 . The second conductive layer 150 may contact the side surface and top surface of the second electrode 146 and the side surface and top surface of the first insulating layer 131 at the first separation distance S1 . In addition, a region in which a Schottky junction is formed by contacting the second conductive layer 150 and the second conductive semiconductor layer 126 within the first separation distance S1 may be disposed, and by forming the Schottky junction, current 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 greater than the resistance between the second electrode 146 and the second conductive semiconductor layer 127. They can be freely arranged 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 pass through the second insulating layer 132 and be electrically connected to the first electrode 142 . The second insulating layer 132 and the first insulating layer 131 may be made of the same material or different materials.

According to the embodiment, since 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, the first insulating layer 131 has defects. Even when this occurs, 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 can easily propagate in the thickness direction. Therefore, external moisture or contaminants may penetrate into the semiconductor structure through the 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, it is difficult for defects formed in the first insulating layer 131 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 propagation of defects.

Referring back to FIG. 7 , 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 lower surface of the semiconductor structure 120 and the shape of the recess 128 . The first conductive layer 165 may be made of a material having excellent reflectivity. Illustratively, the first conductive layer 165 may include aluminum. When the electrode layer 165 includes aluminum, light emitted from the active layer 126 toward the substrate 170 may be upwardly reflected to improve light extraction efficiency. However, the present invention is not limited thereto, and the first conductive layer 165 may provide a function to be electrically connected to the first electrode 142 . The first conductive layer 165 may be disposed without including a material having high reflectivity, for example, aluminum and/or silver (Ag), and in this case, the first electrode 142 disposed in the recess 128 ) and the first conductive layer 165, and between the second conductive semiconductor layer 127 and the first conductive layer 165, a reflective metal layer (not shown) made of a material having high reflectivity may be disposed. .

The bonding layer 160 may include 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. For example, the substrate 170 may include a metal or semiconductor material. The substrate 170 may be a metal having excellent electrical conductivity and/or thermal conductivity. In this case, the heat generated during operation of the semiconductor device can be quickly dissipated to the outside. Also, when the substrate 170 is made of a conductive material, the first electrode 142 can receive 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.

A passivation layer 180 may be disposed on top and side surfaces of the semiconductor structure 120 . The thickness of the passivation layer 180 may be greater than or equal to 200 nm and less than or equal to 500 nm. If it is 200 nm or more, electrical and optical reliability of the device can be improved by protecting the device from external moisture or foreign substances, and if it is 500 nm or less, the stress applied to the semiconductor device can be reduced, and the optical and electrical reliability of the semiconductor device is lowered. It is possible to improve the problem that the unit price of the semiconductor device increases as the processing time of the semiconductor device increases.

An upper surface of the semiconductor structure 120 may have irregularities. Such irregularities may improve extraction efficiency of light emitted from the semiconductor structure 120 . The irregularities may have different average heights depending on the wavelength of the ultraviolet light. In the case of UV-C, light extraction efficiency may be improved when the irregularities have a height of about 300 nm to about 800 nm and an average height of about 500 nm to about 600 nm.

10 is a conceptual diagram of a semiconductor device according to another embodiment of the present invention, and FIG. 11 is a plan view of FIG. 10 .

Referring to FIG. 10 , the above configuration may be applied to the semiconductor structure 120 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 and extend to a partial region of the first conductivity type semiconductor layer 124 .

The semiconductor device may include a side reflector Z1 disposed at an edge. The side reflector Z1 may be formed by protruding from the second conductive layer 150 , the first conductive layer 165 , and the substrate 170 in the thickness direction (Y-axis direction). Referring to FIG. 12 , the side reflector Z1 may be disposed along an edge of the semiconductor device and may be disposed while surrounding the semiconductor structure 120 .

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

An inclination angle of the side reflector Z1 may be greater than 90 degrees and less 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 less than 90 degrees or greater than 145 degrees, the efficiency of upwardly reflecting light moving toward the side may decrease.

12 is a conceptual diagram of a semiconductor device package according to an embodiment of the present invention, FIG. 13 is a plan view of the semiconductor device package according to an embodiment of the present invention, FIG. 14 is a modified example of FIG. 13, and FIG. A cross-sectional view of a semiconductor device package according to another embodiment of the present invention.

Referring to FIG. 12 , the semiconductor device package includes a body 2 having a groove (opening) 3, a semiconductor device 1 disposed in the body 2, and a semiconductor device 1 disposed in the body 2 and A pair of lead frames 5a and 5b electrically connected may be included. The semiconductor device 1 may include all of the above configurations.

The body 2 may include a material or 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 made of the same material or may include different materials. Illustratively, the plurality of layers 2a, 2b, 2c, 2d, and 2e may include an aluminum material.

The groove 3 may be formed to become wider as it moves away from the semiconductor element, 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 necessarily limited thereto. The light-transmitting layer 4 is not particularly limited as long as it is made of a material capable of effectively transmitting ultraviolet light. The inside of the groove 3 may be an empty space.

Referring to FIG. 13 , the semiconductor device 10 may be disposed on the first lead frame 5a and connected to the second lead frame 5b by wires. At this time, the second lead frame 5b may be disposed to surround the side of the first lead frame.

Referring to FIG. 14 , a semiconductor device package may include a plurality of semiconductor devices 10a, 10b, 10c, and 10d. In this case, the lead frame may include first to fifth lead frames 5a, 5b, 5c, 5d, and 5e.

The first semiconductor device 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 a wire. The third semiconductor element 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 connected to the fifth lead frame 5e by a wire.

Referring to FIG. 15 , the semiconductor device package includes 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 inner and outer surfaces of the body 10 according to the embodiment may have conductivity. This structure can have a number of advantages. When a non-conductive material such as AlN or Al ₂ O ₃ is used as the body 10, a reflectance in the ultraviolet wavelength band is only 20% to 40%, so 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. Therefore, manufacturing cost may increase and the process may become complicated. In addition, a conductive member such as gold (Au) has a problem in that light extraction efficiency is reduced by absorbing ultraviolet rays.

However, according to the embodiment, since the body 10 itself is made of aluminum, the reflectance is high in the UV wavelength range, so a separate reflective member can be omitted. In addition, since the body 10 itself is conductive, a separate circuit pattern and lead frame can be omitted. In addition, since it is made of aluminum, thermal conductivity may be excellent at 140 W/m.k to 160 W/m.k. Therefore, heat dissipation efficiency can also be improved.

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

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

The second insulator 41 may be made of the same material as the first insulator 42, but is not necessarily limited thereto. The first insulating portion 42 and the second insulating portion 41 are made of 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, it is possible to prevent burrs from occurring at the edge during package cutting. In the case of an aluminum substrate, burrs may occur relatively well compared to other metal substrates. When a burr is generated, the lower surface 12 is not flat, which may result in poor mounting. In addition, when a burr occurs, the thickness may become non-uniform, and a measurement error may occur.

The third insulator 43 may be disposed on the lower surface 12 of the body 10 and connected to the second insulator 41 and the first insulator 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.

Semiconductor devices may be applied to various types of light source devices. For example, the light source device may include a sterilization device, a curing device, a lighting device, a display device, and a vehicle lamp. That is, the semiconductor element may be applied to various electronic devices disposed in a case to provide light.

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

Illustratively, the water purifier may include a sterilization device according to the embodiment to sterilize circulating water. The sterilization device may be disposed at a nozzle through which water circulates or an outlet to irradiate ultraviolet rays. In this case, the sterilization device may include a waterproof structure.

The curing device may be provided with a semiconductor device according to an embodiment to cure various types of liquids. Liquid may be the lightest concept that includes all various materials that are hardened when irradiated with ultraviolet rays. Illustratively, the curing device may cure various types of resins. Alternatively, the curing device may be applied to curing cosmetic products such as nail polish.

The lighting device may include a light source module including a substrate and the semiconductor device of the embodiment, a heat dissipation unit dissipating heat from the light source module, and a power supply unit that processes or converts an electrical signal received from the outside and provides it to the light source module. Also, the lighting device 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 reflector is disposed on the bottom cover, and the light emitting module can emit light. The light guide plate may be disposed in front of the reflector to guide light emitted from the light emitting module forward, and the optical sheet may include a prism sheet and the like and be disposed in front of the light guide plate. A display panel may be disposed in front of the optical sheet, an image signal output circuit may supply an image signal to the display panel, and a color filter may be disposed in front of the display panel.

When the semiconductor device is used as a backlight unit of a display device, it may be used as an edge-type backlight unit or a direct-type backlight unit.

The semiconductor element may be a laser diode other than the light emitting diode described above.

Like the light emitting device, the laser diode may include the first conductivity type semiconductor layer, the active layer, and the second conductivity type semiconductor layer having the above structure. In addition, an electro-luminescence phenomenon in which light is emitted when a current is passed after bonding a p-type first conductivity type semiconductor and an n-type second conductivity type semiconductor is used, but the directionality of the emitted light There is a difference between and phase. That is, a laser diode can emit light having a specific wavelength (monochromatic beam) with the same phase and in the same direction by using a phenomenon called stimulated emission and a constructive interference phenomenon. Therefore, it can be used for optical communication, medical equipment, and semiconductor processing equipment.

A photodetector, which is a type of transducer that detects light and converts its intensity into an electrical signal, may be exemplified as the light receiving element. As such an optical detector, a photovoltaic cell (silicon, selenium), an optical output device (cadmium sulfide, cadmium selenide), a photodiode (eg, a PD having a peak wavelength in a visible blind spectral region or a true blind spectral region), a photodetector Transistors, photomultiplier tubes, photoelectric tubes (vacuum, gas filled), IR (Infra-Red) detectors, etc., but embodiments are not limited thereto.

In addition, a semiconductor device such as a photodetector may be fabricated using a direct bandgap semiconductor having excellent light conversion efficiency. Alternatively, photodetectors have various structures, and the most common structures include a pin type photodetector using a p-n junction, a Schottky type photodetector using a Schottky junction, and a Metal Semiconductor Metal (MSM) type photodetector. there is.

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

A photovoltaic cell or solar cell is a type of photodiode and can convert light into electric current. A solar cell, like a light emitting device, may include a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer having the above structure.

In addition, it can be used as a rectifier of an electronic circuit through the rectification characteristics of a general diode using a p-n junction, and can be applied to an oscillation circuit by being applied to a microwave circuit.

In addition, the above-described semiconductor device 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 using a p-type or n-type dopant. It may be implemented using a doped semiconductor material or an intrinsic semiconductor material.

Although the above has been described with reference to the embodiments, this is only an example and does not limit the present invention, and those skilled in the art to which the present invention belongs will not deviate from the essential characteristics of the present embodiment. It will be appreciated that various variations and applications are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

Claims (17)

A first conductivity-type semiconductor layer containing aluminum;
a second conductivity-type semiconductor layer containing aluminum; and
A light emitting structure comprising aluminum and including an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer,
When primary ions collide with the light emitting structure so that secondary ions of aluminum are emitted from the first conductivity-type semiconductor layer, the active layer, and the second conductivity-type semiconductor layer, the first conductivity-type semiconductor layer, the active layer, and the Secondary ions each having an intensity are emitted from the second conductivity type semiconductor layer;
The intensity of the secondary ion of aluminum is the intensity at the first point, which is the maximum intensity in the second conductivity type semiconductor layer, the intensity at the third point, which is the minimum intensity in the second conductivity type semiconductor layer, and the intensity at the maximum point in the first conductivity type semiconductor layer. Including the intensity of the second point, which is the intensity, and the intensity of the fourth point, which is the minimum intensity in the first conductivity type semiconductor layer,
a first intensity difference between the intensity of the second point and the intensity of the fourth point is less than a second intensity difference between the intensity of the first point and the intensity of the third point;
The first conductivity type semiconductor layer is disposed between the 1-1 conductivity type semiconductor layer, the 1-2 conductivity type semiconductor layer, and the 1-1 conductivity type semiconductor layer and the 1-2 conductivity type semiconductor layer. Including an intermediate layer that becomes
The aluminum composition of the intermediate layer is smaller than the aluminum composition of the 1-1 conductivity type semiconductor layer and the 1-2 conductivity type semiconductor layer, and the intermediate layer corresponds to the strength of the fourth point;
The semiconductor device of claim 1 , wherein the ratio of the aluminum composition between the second point and the fourth point is 1:0.5 to 1:0.9.
According to claim 1,
The semiconductor device wherein the ratio of the first intensity difference to the second intensity difference is 1:1.5 to 1:2.5.
According to claim 1,
The first conductivity-type semiconductor layer includes a third section, which is the intensity of secondary ions, between the intensity of the second point and the intensity of the fourth point,
The second conductivity type semiconductor layer includes a first period, which is the intensity of secondary ions, between the intensity of the first point and the intensity of the third point,
The semiconductor device according to claim 1 , wherein the active layer includes a second section having a secondary ionic strength between an intensity of the first point and an intensity of the second point.
According to claim 1,
A portion corresponding to the second point has the thinnest thickness in the first conductivity type semiconductor layer.
According to claim 1,
A portion corresponding to the first point has the smallest thickness in the second conductivity type semiconductor layer.
According to claim 1,
The second conductivity-type semiconductor layer is a P-type semiconductor layer and a blocking layer, the first conductivity-type semiconductor layer is an N-type semiconductor layer, and the first point is in the blocking layer.
According to claim 6,
The P-type semiconductor layer includes a 2-1st conductivity type semiconductor layer, a 2-2nd conductivity type semiconductor layer, and a 2-3rd conductivity type semiconductor layer,
The 2-3 conductivity type semiconductor layer is positioned relatively closer to the active layer than the 2-1 conductivity type semiconductor layer and the 2-2 conductivity type semiconductor layer, and the 2-2 conductivity type semiconductor layer is the second conductivity type semiconductor layer. It is located between the 2-1 conductivity type semiconductor layer and the 2-3 conductivity type semiconductor layer,
The aluminum composition of the 2-1 conductivity type semiconductor layer is lower than the aluminum composition of the 2-2 conductivity type semiconductor layer, and the aluminum composition of the 2-3 conductivity type semiconductor layer is the 2-1 conductivity type semiconductor layer. and a semiconductor element having a higher aluminum composition than that of the 2-2 conductivity type semiconductor layer.
According to claim 6,
The P-type semiconductor layer includes at least one of a 2-1st conductivity type semiconductor layer and a 2-2nd conductivity type semiconductor layer,
The 2-1 conductivity type semiconductor layer is located relatively further from the active layer than the 2-2 conductivity type semiconductor layer, the third point is at the 2-1 conductivity type semiconductor layer, and the second A semiconductor device in which the aluminum composition of the -1 conductivity type semiconductor layer or the 2-2 conductivity type semiconductor layer gradually increases in a first direction from the P-type semiconductor layer toward the active layer.
According to claim 6,
The blocking layer is a semiconductor device having an aluminum composition in the range of 50% to 100%.
According to claim 6,
The blocking layer includes a 1-1 section, a 1-2 section, and a 1-3 section between the 1-1 section and the 1-2 section,
The aluminum composition of the 1-1 section is greater than the aluminum composition of the 1-2 section and the 1-3 section,
The 1-1 section is the semiconductor device closest to the active layer in the blocking layer.
According to claim 10,
The semiconductor device wherein the aluminum composition of the section 1-1 is 80% to 100%.
According to claim 1,
The first conductivity-type semiconductor layer has an intensity of the second point in a portion of the first conductivity-type semiconductor layer closest to the active layer.
According to claim 1,
An intensity appearing in the active layer is lower than intensity at the first point and higher than intensity at the third point.
According to claim 1,
The second conductive semiconductor layer includes a first semiconductor material having a composition formula In _x5 Al _y2 Ga _1-x5-y2 N (0≤x5≤1, 0≤y2≤1, and 0≤x5+y2≤1) And, the first conductivity-type semiconductor layer is a second semiconductor material having a composition formula In _x1 Al _y1 Ga _1-x1-y1 N (0≤x1≤1, 0≤y1≤1, and 0≤x1+y1≤1) The well layer of the active layer includes a third semiconductor material having a composition formula In _x2 Al _y2 Ga _1-x2-y2 N (0≤x2≤1, 0≤y2≤1, and 0≤x2+y2≤1) A semiconductor device comprising:
delete A semiconductor structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer;
a first electrode electrically connected to the first conductivity type semiconductor layer; and
A second electrode electrically connected to the second conductivity type semiconductor layer;
The second conductivity type semiconductor layer includes a first location having the highest aluminum composition and a third location having the lowest aluminum composition in the second conductivity type semiconductor layer;
The first conductivity type semiconductor layer includes a second location having the highest aluminum composition and a fourth location having the lowest aluminum composition in the first conductivity type semiconductor layer;
The ratio of the aluminum composition between the third point and the first point is 1:4 to 1:100,
The ratio of the aluminum composition between the second point and the fourth point is 1:0.5 to 1:0.9,
The second conductivity-type semiconductor layer is a P-type semiconductor layer, the first conductivity-type semiconductor layer is an N-type semiconductor layer, and the active layer includes a plurality of well layers and a plurality of barrier layers alternately disposed with the well layers. do,
The first conductivity type semiconductor layer is disposed between the 1-1 conductivity type semiconductor layer, the 1-2 conductivity type semiconductor layer, and the 1-1 conductivity type semiconductor layer and the 1-2 conductivity type semiconductor layer. Including an intermediate layer that becomes
The aluminum composition of the intermediate layer is smaller than the aluminum composition of the 1-1 conductivity type semiconductor layer and the 1-2 conductivity type semiconductor layer.
17. The semiconductor device of claim 16, wherein the second point is closest to the active layer in the first conductivity type semiconductor layer.

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