KR20200001177A - A vertical-cavity surface-emitting laser device and light emitting device including the same - Google Patents

Abstract

A surface light emitting laser device capable of improving light output comprises: a substrate; a first reflection layer disposed on the substrate; an active layer disposed on the first reflection layer; an oxide layer disposed on the active layer and including an aperture and insulating area; and a second reflection layer disposed on the oxide layer. The oxide layer may include a first semiconductor area, a second semiconductor area on the first semiconductor area, and a third semiconductor area on the second semiconductor area. The first to third semiconductor areas may include Al, and the Al concentration of the second semiconductor area may be lower than the Al concentration of the third semiconductor area.

Description

Surface-emitting laser device and light emitting device including the same {A VERTICAL-CAVITY SURFACE-EMITTING LASER DEVICE AND LIGHT EMITTING DEVICE INCLUDING THE SAME}

Embodiments relate to a surface emitting laser device and a light emitting device including the same.

A semiconductor device including a compound such as GaAs or AlGaAs may emit light of various wavelength bands by using a wide and easy to adjust band gap energy, and thus may be variously used as a light emitting device, a light receiving device, 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 have been developed using thin film growth technology and device materials. Various colors such as ultraviolet rays can be realized, and efficient white light can be realized by using fluorescent materials or by combining colors.Low power consumption, semi-permanent life, fast response speed, It has the advantages of safety and environmental friendliness.

In addition, when a light receiving device such as a photodetector or a solar cell is manufactured by using a group 3-5 or group 2-6 compound semiconductor material, the development of device materials absorbs light in various wavelength bands, thereby generating a photocurrent. It can receive light in various wavelength bands, ranging from radio wavelength bands. In addition, semiconductor devices have the advantages of fast response speed, safety, environmental friendliness, and easy control of device materials, so that they can be easily adopted in power control or microwave circuits or communication modules.

Therefore, the semiconductor device may replace a transmission / reception module of an optical communication system, a light emitting unit that replaces a cold cathode fluorescent lamp (CCFL) constituting a backlight of a liquid crystal display (LCD), a fluorescent lamp, or an incandescent bulb. Applications are expanding to lighting devices such as white light emitting diodes, automotive headlights, traffic lights or sensors to detect gas or fire.

In addition, the semiconductor device may be extended to high frequency application circuits, other power control devices, and communication modules. For example, there is a surface-emitting laser (VCSEL) device as a semiconductor device. Surface emitting laser devices are used in optical communication, optical parallel processing, optical connection, and the like. On the other hand, the laser diode used in such a communication module is designed to be easy to operate at a low current.

On the other hand, the response speed is important in the existing data optical communication structure, but recently, as the surface emitting laser device is applied to a high power package for a sensor, light output and voltage efficiency become important characteristics.

Surface-emitting laser devices are employed in 3D sensing cameras. For example, a 3D sensing camera is a camera capable of capturing depth information of an object, and has recently been in the spotlight in conjunction with augmented reality. On the other hand, a depth sensor of the camera module is equipped with a separate sensor, it is divided into two types, such as a structured light (SL) method and ToF (Time of Flight) method.

In the structured light (SL) method, a laser of a specific pattern is emitted to a subject, the depth of field is calculated based on the degree of deformation of the pattern according to the shape of the subject surface, and then synthesized with the photograph taken by the image sensor to display the 3D photographing result. You get

In contrast, the ToF method calculates the depth by measuring the time when the laser is reflected back to the subject, and then synthesizes it with the photograph taken by the image sensor to obtain a 3D photographing result.

As a result, the SL method has an advantage in mass production in that the laser has to be positioned very precisely, while the ToF technology relies on an improved image sensor, and it is possible to employ either method or both in one mobile phone. It may be.

For example, a 3D camera called True Depth may be installed in the SL method on the front of the mobile phone, and may be installed in the ToF method on the back of the mobile phone.

The conventional surface emitting laser device has the following problems.

First, the VCSEL structure increases reflectance through a large number of reflective layers, for example, distributed Bragg reflectors (DBRs). For example, DBR increases the reflectivity by alternately arranging AlxGaAs-based materials with different Al concentrations. However, in order to solve a problem in which series resistance occurs in the DBR, an attempt is made to improve the voltage efficiency by increasing the doping concentration of the DBR to lower the resistance. However, when the doping concentration is increased, there is a technical contradiction in which the internal light absorption is generated by the dopant and the light output is lowered.

In addition, the DBR is arranged by alternating AlxGaAs-based materials with different Al concentrations, thereby reducing the electric field by the energy band bending generated at the interface between adjacent layers in the DBR. The electric field acts as a carrier barrier, resulting in a decrease in light output.

Second, optical power and voltage efficiency are important in the development of a high power package employing a VCSEL device, and there is a limit to improving the optical power and the voltage efficiency simultaneously. For example, the VCSEL device has an active region including an active layer and a cavity, and the active region has a technical problem in that the internal resistance is high and the driving voltage is increased to decrease the voltage efficiency.

Third, in order to improve light output in the prior art, optical confinement is required around the active layer, and there is no suitable solution for this in the prior art.

Fourth, when a current is applied to the surface emitting laser device, a current crowding phenomenon occurs in which the current is concentrated along an aperture edge. Due to the current density phenomenon, the film quality of the aperture, which is the laser emission region, may be damaged. In addition, due to the current density phenomenon, the temperature of the aperture is raised, an optical problem that the divergence angle (beam) of the beam passing through the aperture is increased. The effect of affecting the divergence angle of the beam passing through the aperture by the current density phenomenon is called the thermal lens effect.

The embodiment aims to solve the above and other problems.

Another object of the embodiment is to provide a surface emitting laser device and a light emitting device including the same.

Still another object of the embodiment is to provide a surface emitting laser device having a novel structure and a light emitting device including the same.

Still another object of the embodiment is to provide a surface emitting laser device capable of improving light output, and a light emitting device including the same.

Still another object of the embodiment is to provide a surface emitting laser device and a light emitting device including the same, which can improve light concentration efficiency.

Still another object of the embodiment is to provide a surface emitting laser device and a light emitting device including the same, which can alleviate current density to prevent variations in the divergence angle of the beam.

According to a first aspect of the embodiment to achieve the above or another object, the surface emitting laser device, the substrate, a first reflective layer disposed on the substrate; An active layer disposed on the first reflective layer; An oxide layer disposed on the active layer and including an opening and an insulating region; And a second reflective layer disposed on the oxide layer. The opening may include a first semiconductor region; A second semiconductor region on the first semiconductor region; And a third semiconductor region on the second semiconductor region. The first to third semiconductor regions may include Al, and an Al concentration of the second semiconductor region may be lower than an Al concentration of the first or third semiconductor region.

According to a second aspect of the embodiment, the surface emitting laser device comprises: a substrate; A first reflective layer disposed on the substrate; An active layer disposed on the first reflective layer; An oxide layer disposed on the active layer and including an opening and an insulating region; And a second reflective layer disposed on the oxide layer. The opening may include a first semiconductor region; A second semiconductor region on the first semiconductor region; And a third semiconductor region on the second semiconductor region. The first to third semiconductor regions may include Al, and the Al concentration of the second semiconductor region may be higher than the Al concentration of the first or third semiconductor region.

According to the third aspect of the embodiment, the light emitting device may include the surface light emitting laser element.

The effects of the surface emitting laser device and the light emitting device including the same according to the embodiment will be described below.

According to at least one of the embodiments, the oxide layer is composed of a plurality of layers, for example, the first to third oxide layer, there is an advantage that the stress stress of the oxide layer generated when the oxide layer is composed of a single layer is alleviated.

According to at least one of the embodiments, in the openings including the first to third semiconductor regions, a second semiconductor region having a small band gap is disposed between the first semiconductor region and the third semiconductor region having a large band gap, thereby providing a first semiconductor region. The current concentration in the third semiconductor region can be relaxed and the diffraction effect can be reduced.

According to at least one of the embodiments, the shrinkage stress is caused by a sandwich structure in which the second semiconductor region 241b having a small band gap is disposed between the first semiconductor region 241a and the third semiconductor region 241c having a large band gap. This can be alleviated, so that the deterioration of the laser beam emission characteristics can be prevented due to the bending characteristics of the surface-emitting laser device.

According to at least one of the embodiments, when In is added to the second semiconductor region including the first to third semiconductor regions to further reduce the band gap, holes generated in the second reflective layer may cause the third semiconductor region. It may be moved along the transverse direction in the second semiconductor region via. Accordingly, the current may not only flow to the light emitting layer via the first semiconductor region along the vertical direction in the second semiconductor region, but may also flow along the transverse direction in the second semiconductor region. That is, since current is distributed in the vertical direction and the lateral direction in the second semiconductor region, the current density phenomenon in which the current is concentrated along the aperture edge can be alleviated.

According to at least one of the embodiments, a first to third oxide layer is provided, the first oxide layer comprises a first semiconductor region and a first insulating region, and the second oxide layer comprises a second semiconductor region and a second insulating region. The third oxide layer may include a third semiconductor region and a third insulating region. In this case, movement of holes generated in the second reflective layer to the second semiconductor region via the third semiconductor region may be suppressed by the second disturbing region of the third insulating region. In addition, movement of holes moved to the second semiconductor region to the light emitting layer through the first semiconductor region may be suppressed by the first interference region of the first insulating region. In addition, holes moved to the second semiconductor region may be dispersed and moved not only in the vertical direction but also in the transverse direction. Accordingly, the movement of holes is suppressed at the openings of the oxide layer, that is, at the edges of the openings including the first to third semiconductor regions, and the holes are dispersed in the vertical direction and the horizontal direction, thereby preventing the current dense phenomenon and changing the divergence angle of the beam. It is not possible to output a precise laser beam.

Further scope of the applicability of the embodiments will become apparent from the detailed description below. However, various changes and modifications within the spirit and scope of the embodiments can be clearly understood by those skilled in the art, and therefore, specific embodiments, such as the detailed description and the preferred embodiments, are to be understood as given by way of example only.

1 is a plan view of a surface emitting laser device according to a first embodiment.
FIG. 2 is an enlarged view of a first region C1 of the surface emitting laser device according to the embodiment shown in FIG. 1.
3A is a first cross-sectional view taken along line A1-A2 of the surface emitting laser device according to the embodiment shown in FIG. 2.
3B is a second cross-sectional view taken along line A3-A4 of the surface emitting laser device according to the embodiment shown in FIG. 2.
4 is a cross-sectional view of a first portion B1 of the surface emitting laser device according to the embodiment shown in FIG. 3A.
5 is first distribution data of refractive index and light energy in the surface emitting laser device according to the second embodiment.
6 is second distribution data of refractive indices in the surface emitting laser device according to the second embodiment.
7 is a cross-sectional view of the surface emitting laser device according to the third embodiment.
FIG. 8 shows a band gap that varies depending on whether In is added in the third embodiment.
9 shows the degree of current density according to the third embodiment.
10 is a cross-sectional view of the surface emitting laser device according to the fourth embodiment.
FIG. 11 shows a bandgap that varies depending on whether In is added in the fourth embodiment.
12 shows a current density level according to the fourth embodiment.
13 is a cross-sectional view of the surface emitting laser device according to the fifth embodiment.
14 shows the flow of holes in the fifth embodiment.
15 shows the current density level according to the fifth embodiment.
16A to 20B are manufacturing process diagrams of the surface emitting laser device according to the embodiment.
21 is a cross-sectional view of the surface emitting laser device according to the sixth embodiment.
22 is a perspective view of a mobile terminal to which a surface emitting laser device is applied according to an embodiment.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

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

(First embodiment)

1 is a plan view of a surface emitting laser device 201 according to an embodiment, and FIG. 2 is an enlarged view of a first region C1 of the surface emitting laser device according to the embodiment shown in FIG. 1.

Referring to FIG. 1, the surface emitting laser device 201 according to the embodiment may include a light emitting layer E and a pad part P. FIG. As shown in FIG. 2, the light emitting layer E may include a plurality of light emitting emitters E1, E2, and E3. For example, the light emitting layer E may comprise tens to hundreds of light emitting emitters.

Referring to FIG. 2, in an embodiment, the surface emitting laser device 201 may include a second electrode 280 defining an opening. That is, the second electrode 280 may be disposed in the remaining regions except for the region corresponding to the aperture 241. For example, the second electrode 280 may be disposed in the second region of the second reflective layer 250. The first region of the second reflective layer 250 is surrounded by the second region and may be equal to or larger than the size of the opening 241. Accordingly, the beam generated in the light emitting layer 230 may pass through the opening 241 to be emitted to the outside through the opening defined by the second electrode part 280.

3A is a first cross-sectional view taken along line A1-A2 of the surface light emitting laser device according to the embodiment shown in FIG. 2, and FIG. 3B is a line A3-A4 of the surface light emitting laser device according to the embodiment shown in FIG. Second cross section according to.

3A and 3B, in an embodiment, the surface light emitting laser device 201 may include a first electrode 215, a substrate 210, a first reflective layer 220, a light emitting layer 230, an oxide layer 240, and a second light emitting device. One or more of the second reflective layer 250, the passivation layer 270, and the second electrode 280 may be included.

The oxide layer 240 may include an opening 241 and an insulating region 242. The opening 241 may be a passage area through which current flows. The insulating region 242 may be a blocking region that blocks the flow of current. The insulating region 242 may be referred to as an oxide layer or an oxide layer.

The oxide layer 240 may be referred to as a current confinement layer because it restricts the flow or density of the current to emit a more coherent laser beam.

The second electrode 280 may include a contact electrode 282 and a pad electrode 284.

4 is an enlarged cross-sectional view of the first portion B1 of the surface emitting laser device according to the embodiment shown in FIG. 3A.

Hereinafter, technical features of the surface emitting laser device 201 according to the exemplary embodiment will be described with reference to FIGS. 1 to 4. In the drawings of the embodiment, the direction of the x-axis may be a direction parallel to the longitudinal direction of the substrate 210, the y-axis may be a direction perpendicular to the x-axis.

<Substrate, first electrode>

The surface emitting laser device 201 according to the embodiment provides a substrate 210. The substrate 210 may be a conductive substrate or a nonconductive substrate. As the conductive substrate, a metal having excellent electrical conductivity may be used. Since the heat generated during the operation of the surface emitting laser device 201 should be sufficiently dissipated, a GaAs substrate or a metal substrate having high thermal conductivity or a silicon (Si) substrate may be used as the conductive substrate. As the non-conductive substrate, an AlN substrate, a sapphire (Al ₂ O ₃ ) substrate, or a ceramic substrate may be used.

The surface emitting laser device 201 according to the embodiment provides the first electrode 215. The first electrode 215 may be disposed under the substrate 210. The first electrode 215 may be disposed in a single layer or multiple layers of a conductive material. For example, the first electrode 215 may be a metal and include at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). Therefore, it is formed in a single layer or a multi-layer structure, it is possible to improve the electrical characteristics to increase the light output.

<1st reflective layer>

The surface emitting laser device 201 according to the embodiment provides the first reflective layer 220. The first reflective layer 220 may be disposed on the substrate 210. When the substrate 210 is omitted to reduce the thickness, the bottom surface of the first reflective layer 220 may contact the top surface of the first electrode 215.

The first reflective layer 220 may be doped with a first conductivity type dopant. For example, the first conductivity type dopant may include an n type dopant such as Si, Ge, Sn, Se, Te, or the like.

The first reflective layer 220 may include a gallium-based compound, for example, AlGaAs, but is not limited thereto. The first reflective layer 220 may be a distributed bragg reflector (DBR). For example, the first reflective layer 220 may have a structure in which a first layer and a second layer including materials having different refractive indices are alternately stacked at least once.

For example, as shown in FIG. 4, the first reflective layer 220 is disposed on the first group first reflective layer 221 and the first group first reflective layer 221 disposed on the substrate 210. It may include a first reflective layer 222.

The first group first reflecting layer 221 and the second group first reflecting layer 222 may include a plurality of layers including a semiconductor material having a composition formula of Al _x Ga _(1-x) As (0 <x <1). As the Al in each layer increases, the refractive index of each layer may decrease, and as Ga increases, the refractive index of each layer may increase. The thickness of each layer may be λ / 4n, λ may be the wavelength of light generated in the light emitting layer 230, and n may be the refractive index of each layer for light of the above-described wavelength. Here, λ may be 650 to 980 nanometers (nm), and n may be the refractive index of each layer. The first reflective layer 220 having such a structure may have a reflectance of 99.999% for light having a wavelength of about 940 nanometers.

The thickness of the layer in each first reflective layer 220 may be determined according to the refractive index and the wavelength λ of the light emitted from the light emitting layer 230.

As shown in FIG. 4, the first group first reflective layer 221 may be formed of a single layer or a plurality of layers. For example, the first group first reflective layer 221 may include about 30-40 pairs of the first group first-first layer 221a and the first group first-second layer 221b. have. The first group first-first layer 221a may be formed thicker than the first group first-second layer 221b. For example, the first group first-first layer 221a may be formed at about 40 to 60 nm, and the first group first-2 layer 221b may be formed at about 20-30 nm.

In addition, each of the second group first reflective layers 222 may be formed of a single layer or a plurality of layers. The second group first reflective layer 222 may include about 5 to 15 pairs of the second group first-first layer 222a and the second group first-second layer 222b. The second group first-first layer 222a may be formed thicker than the second group first-second layer 222b. For example, the second group 1-1 layer 222a may be formed at about 40 nm to about 60 nm, and the second group 1-2 layer 222 b may be formed at about 20 nm to about 30 nm.

<Active layer>

The surface emitting laser device 201 according to the embodiment may include a light emitting layer 230. The light emitting layer 230 may be disposed on the first reflective layer 220. In detail, the emission layer 230 may be disposed on the second group first reflection layer 222. The light emitting layer 230 may be disposed between the first reflective layer 220 and the second reflective layer 250.

The emission layer 230 may include an active layer 232 and at least one cavity 231 and 233. For example, the emission layer 230 may include an active layer 232, a first cavity 231 disposed under the active layer 232, and a second cavity 233 disposed above the active layer 232. . The light emitting layer 230 of the embodiment may include both the first cavity 231 and the second cavity 233, or may include only one of the two.

The active layer 232 may include 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, and a quantum line structure.

The active layer 232 may include a quantum well layer 232a and a quantum wall layer 232b using a group 3-5 or group 2-6 compound semiconductor material. The quantum well layer 232a may be formed of a material having an energy band gap smaller than the energy band gap of the quantum wall layer 232b. The active layer 232 may be formed in a 1 to 3 pair structure such as InGaAs / AlxGaAs, AlGaInP / GaInP, AlGaAs / AlGaAs, AlGaAs / GaAs, GaAs / InGaAs, but is not limited thereto. Dopants may not be doped in the active layer 232.

The first cavity 231 and the second cavity 233 may be formed of Al _y Ga _(1-y) As (0 <y <1) material, but is not limited thereto. For example, the first cavity 231 and the second cavity 233 may each include a plurality of layers made of Al _y Ga _(1-y) As.

For example, the first cavity 231 may include the first-first cavity layer 231a and the first-second cavity layer 231b disposed on the first-first cavity layer 231a. The first-first cavity layer 231a may be further spaced apart from the active layer 232 than the first-second cavity layer 231b. The first-first cavity layer 231a may be formed thicker than the first-second cavity layer 231b, but is not limited thereto. For example, the first-first cavity layer 231a may be formed to about 60 to 70 nm, and the first-second cavity layer 231b may be formed to about 40 to 55 nm, but is not limited thereto.

In addition, the second cavity 233 may include a 2-1 cavity layer 233a and a 2-2 cavity layer 233b disposed on the 2-1 cavity layer 233a. The 2-2 cavity layer 233b may be further spaced apart from the active layer 232 than the 2-1 cavity layer 233a. The 2-2 cavity layer 233b may be formed thicker than the 2-1 cavity layer 233a, but is not limited thereto. For example, the second-2 cavity layer 233b may be formed to about 60 to 70 nm, and the second first cavity layer 233a may be formed to about 40 to 55 nm, but is not limited thereto.

<Oxide layer>

The surface emitting laser device according to the embodiment may provide the oxide layer 240. The oxide layer 240 may include an insulating region 242 and an opening 241. The insulating region 242 may surround the opening 241. For example, the opening 241 may be disposed on the first area (center area) of the light emitting layer 230, and the insulating area 242 may be disposed on the second area (edge area) of the light emitting layer 230. The second region may surround the first region.

The opening 241 may be a passage area through which current flows. The insulating region 242 may be a blocking region that blocks the flow of current. The insulating region 242 may be referred to as an oxide layer or an oxide layer.

The amount of current supplied from the second electrode 280 to the light emitting layer 230, that is, the current density may be determined by the size of the opening 241. The size of the opening 241 may be determined by the insulating region 242. As the size of the insulating region 242 increases, the size of the opening 241 decreases, and accordingly, the current density supplied to the light emitting layer 230 may increase. In addition, the opening 241 may be a passage through which the beam generated in the emission layer 230 travels in an upward direction, that is, in a direction of the second reflective layer 250. That is, the divergence angle of the beam of the light emitting layer 230 may vary according to the size of the opening 241.

The insulating region 242 may be formed of an insulating layer, for example, aluminum oxide (Al ₂ O ₃ ). For example, when the oxide layer 240 includes aluminum gallium arsenide (AlGaAs), the AlGaAs of the oxide layer 240 reacts with H ₂ O to change the edge to aluminum oxide (Al ₂ O ₃ ), thereby insulating the region 242. The central region formed of) and not reacted with H ₂ O may be an opening 241 including AlGaAs.

According to the embodiment, the light emitted from the light emitting layer 230 through the opening 241 may be emitted to the upper region, and the light transmittance of the opening 241 may be excellent compared to the insulating region 242.

Referring to FIG. 4, the insulating region 242 may include a plurality of layers. For example, the insulating region 242 may be formed on the first insulating region 242a and the first insulating region 242a. The second insulating region 242b and the third insulating region 242c may be disposed between the second insulating region 242b. One insulating region of the first to third insulating regions 242a, 242b, and 242c may have the same thickness or different thickness as the other insulating region. The first to third insulating regions 242a, 242b, and 242c may include at least an oxidation material. The first to third insulating regions 242a, 242b, and 242c may include at least a group 3-5 or a group 2-6 compound semiconductor material.

<Second reflective layer>

The surface emitting laser device according to the embodiment may include a second reflective layer 250. The second reflective layer 250 may be disposed on the oxide layer 240.

The second reflective layer 250 may include a gallium-based compound, for example AlGaAs, and the second reflective layer 250 may be doped with a second conductive dopant. The second conductivity type dopant may be a p-type dopant such as Mg, Zn, Ca, Sr, Ba, or the like. Meanwhile, the first reflective layer 220 may be doped with a p-type dopant, and the second reflective layer 250 may be doped with an n-type dopant.

The second reflecting layer 250 may also be a distributed Bragg reflector (DBR). For example, the second reflective layer 250 may have a structure in which a plurality of layers including materials having different refractive indices are alternately stacked at least once.

Each layer of the second reflective layer 250 may include AlGaAs, and in detail, may be formed of a semiconductor material having a compositional formula of Al _x Ga _(1-x) As (0 <x <1). Herein, when Al increases, the refractive index of each layer may decrease, and when Ga increases, the refractive index of each layer may increase. The thickness of each layer of the second reflective layer 250 is λ / 4n, λ may be a wavelength of light emitted from the active layer, and n may be a refractive index of each layer with respect to light of the aforementioned wavelength.

The second reflective layer 250 having such a structure may have a reflectance of 99.9% for light having a wavelength of about 940 nanometers.

The second reflective layer 250 may be formed by alternately stacking layers, and the number of pairs of layers in the first reflective layer 220 may be greater than the number of pairs of layers in the second reflective layer 250. . As described above, the reflectance of the first reflective layer 220 may be 99.999%, which may be greater than 99.9% of the reflectance of the second reflective layer 250.

In an exemplary embodiment, the second reflecting layer 250 may be spaced apart from the first group of the second reflecting layer 251 and the first group of the second reflecting layer 251, which is disposed adjacent to the light emitting layer 230. The second reflective layer 252 may be included.

The first group second reflecting layer 251 and the second group second reflecting layer 252 may also be formed of a single layer or a plurality of layers, respectively.

For example, the first group second reflective layer 251 may include about 1 to 5 pairs of the first group 2-1 layer 251a and the first group 2-2 layer 251b. have. The first group 2-1 layer 251a may be formed thicker than the first group 2-2 layer 251b. For example, the first group 2-1 layer 251a may be formed at about 40-60 nm, and the first group 2-2 layer 251b may be formed at about 20-30 nm.

In addition, the second group second reflection layer 252 may also include about 5 to 15 pairs of the second group 2-1 layer 252a and the second group 2-2 layer 252b. The second group 2-1 layer 252a may be formed thicker than the second group 2-2 layer 252b. For example, the second group 2-1 layer 252a may be formed to about 40 to 60 nm, and the second group 2-2 layer 252b may be formed to about 20 to 30 nm.

Passivation layer, second electrode

The surface emitting laser device according to the embodiment may provide the passivation layer 270. The passivation layer 270 may surround a portion of the light emitting structure. Some regions of the light emitting structure may include, for example, the light emitting layer 230, the oxide layer 240, and the second reflective layer 250. The passivation layer 270 may be disposed on the top surface of the first reflective layer 220. The passivation layer 270 may be disposed on an edge region of the second reflective layer 250. When the light emitting structure is partially mesa-etched, a portion of the upper surface of the first reflective layer 220 may be exposed, and a portion of the light emitting structure may be formed. The passivation layer 270 may be disposed on a circumference of a portion of the light emitting structure and on an upper surface of the exposed first reflective layer 220.

The passivation layer 270 may protect the light emitting structure from the outside and block electrical short between the first reflective layer 220 and the second reflective layer 250. The passivation layer 270 may be formed of an inorganic material such as SiO ₂ , but is not limited thereto.

The surface emitting laser device according to the embodiment may provide the second electrode 280. The second electrode 280 may include a contact electrode 282 and a pad electrode 284 connected to the contact electrode 282. The contact electrode 282 may be in contact with a portion of the top surface of the second reflective layer 250. The contact electrode 282 may be formed to improve ohmic characteristics with the second reflective layer 250, but is not limited thereto. The pad electrode 284 may connect the contact electrode 282 and the pad portion (P of FIG. 1).

The contact electrode 282 and the pad electrode 284 may be made of a conductive material. For example, the contact electrode 282 and the pad electrode 284 include at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). It can be formed into a single layer or a multi-layer structure.

(2nd Example)

5 and 6, the technical effects of the surface emitting laser device 202 according to the second embodiment will be described in detail. The second embodiment may employ the technical features of the first embodiment, and will be described below with reference to the main features of the second embodiment.

5 is first distribution data of refractive index and light energy in the surface emitting laser device 202 according to the second embodiment.

According to the second embodiment, the distribution E of the light energy emitted from the surface emitting laser device has a maximum value around the light emitting layer 230 as shown in FIG. 5, and the further away from the light emitting layer 230 is shown. It may decrease in a predetermined period. Meanwhile, in the embodiment, the light energy distribution E is not limited to the distribution data shown in FIG. 5, and the light energy distribution in each layer may be different from that shown in FIG. 5 by the composition, thickness, etc. of each layer.

Referring to FIG. 5, the surface emitting laser device 202 according to the second embodiment is disposed between the first reflective layer 220, the second reflective layer 250, and the first reflective layer 220 and the second reflective layer 250. It may include a light emitting layer 230. In this case, the surface light emitting laser device 202 according to the second embodiment has a refractive index n according to the materials of each of the first reflective layer 220, the light emitting layer 230, and the second reflective layer 250. It may be the same but is not limited thereto.

One of the technical problems of the embodiment is to provide a surface emitting laser device and a light emitting device including the same capable of improving the light output by minimizing the influence of the carrier barrier caused by the generation of the electric field in the reflective layer.

Referring to FIG. 5, the light energy distribution E according to the position of the surface light emitting laser device 202 according to the second embodiment may be known. As described above, the light energy distribution is relatively spaced apart from the light emitting layer 230. (E) may be lowered. The second embodiment controls the concentration of the first conductivity type dopant in the first group first reflection layer 221 to be higher than the dopant concentration in the second group first reflection layer 222 in consideration of the light energy distribution (E). can do.

For example, as shown in FIG. 4, in the embodiment, the first reflective layer 220 includes the first group first reflective layer 221 and the first group first reflective layer 221 disposed on one side of the light emitting layer 230. It may include a second group first reflective layer 222 disposed closer to the light emitting layer 230.

In this case, the light energy of the second group first reflection layer 222 disposed adjacent to the emission layer 230 is higher than the light energy of the first group first reflection layer 221.

The embodiment controls the concentration of the first conductivity type dopant in the second group first reflective layer 222 to be lower than the dopant concentration in the first group first reflective layer 221 in consideration of the light energy distribution E, The first conductivity type dopant may be relatively doped in the region of the first group first reflective layer 221 where the light energy is relatively low. Accordingly, in the second group first reflective layer 222, the light absorption by the dopant is minimized to improve the light output, and in the first group first reflective layer 221, the voltage efficiency is improved by improving the resistance by the relatively high dopant. There is a specific technical effect that can provide a surface light emitting laser device and a light emitting device including the same, which can improve the light output and voltage efficiency simultaneously.

For example, the concentration of the first conductivity type dopant in the first group first reflective layer 221 may be about 2.00E18 and about 1.00E18 in the second group first reflective layer 222, but is not limited thereto. no.

In addition, in the exemplary embodiment, the second reflective layer 250 may be formed to be spaced apart from the first group second reflective layer 251 and the first group second reflective layer 251 disposed adjacent to the light emitting layer 230. The second group second reflection layer 252 may be included.

In this case, the light energy of the first group second reflective layer 251 disposed adjacent to the light emitting layer 230 is higher than the light energy of the second group second reflective layer 252.

Accordingly, the embodiment controls the concentration of the second conductivity type dopant in the first group second reflective layer 251 to be lower than the dopant concentration in the second group second reflective layer 252 in consideration of the light energy distribution, The second conductivity type dopant may be relatively doped in the region of the second group second reflective layer 252 where the light energy is relatively low. Accordingly, in the first group second reflective layer 251, the light absorption by the dopant is minimized to improve the light output, and in the second group second reflective layer 252, the voltage efficiency is improved by the resistance improvement by the dopant. There is a specific technical effect to provide a surface emitting laser device and a light emitting device including the same that can improve the light output and voltage efficiency at the same time.

In the embodiment, in consideration of the light energy distribution (E), the doping concentration can be lowered in the region where the light energy is high, and the doping concentration is controlled in the region where the light energy is low, thereby affecting the carrier barrier caused by the generation of the electric field in the reflective layer. It is possible to provide a surface light emitting laser device and a light emitting device including the same, which can minimize light emission and improve light output.

Next, one of the technical problems of the embodiment is to provide a surface emitting laser device and a light emitting device including the same capable of improving the light output by minimizing the influence of the carrier barrier caused by the generation of the electric field in the reflective layer.

Referring back to FIG. 5, the distribution of light energy (E) according to position in the surface emitting laser device according to the embodiment can be seen. As the relative distance from the light emitting layer 230 is relatively reduced, the light energy distribution is lowered. In consideration of the distribution, the concentration of the first conductivity type dopant in the first group second reflection layer 251 may be controlled to be lower than the concentration of the dopant in the second group second reflection layer 252.

For example, the concentration of the first conductivity type dopant in the first group second reflective layer 251 may be about 7.00E17 to 1.50E18 and about 1.00E18 to about the second group second reflective layer 252. Can be controlled by 3.00E18. In the embodiment, the concentration unit 1.00E18 may mean 1.00 × 10 ¹⁸ (atoms / cm ³ ). In an embodiment, the p-type dopant may be C (Carbon), but is not limited thereto.

Accordingly, the embodiment controls the concentration of the second conductivity type dopant in the second group second reflecting layer 252 to be higher than the dopant concentration in the first group second reflecting layer 251 and has a relatively high light energy. By relatively low doping the second conductivity type dopant in the region of the group second reflective layer 251, the first group second reflective layer 251 minimizes light absorption by the dopant, thereby improving light output and making the second group agent. The second reflective layer 252 improves the voltage efficiency by improving the resistance by a relatively high dopant, thereby providing a surface light emitting laser device capable of simultaneously improving the light output and the voltage efficiency and a unique technology capable of providing a light emitting device including the same. It works.

(Third embodiment)

FIG. 7 is a cross-sectional view of the surface-emitting laser device according to the third embodiment, FIG. 8 shows a band gap which varies depending on whether In is added in the third embodiment, and FIG. 9 shows a current density degree according to the third embodiment. Shows.

FIG. 7 is an enlarged view of an opening 241 and an insulating region 242 of the surface light emitting laser device illustrated in FIG. 3A.

The third embodiment may be the same as the first and second embodiments except for the opening 241 and the insulating region 242. In the third embodiment, components having the same structure, shape, and / or function as those in the first and second embodiments will be denoted by the same reference numerals and detailed description thereof will be omitted. Technical matters omitted in the following description can be easily understood from the above-described first and second embodiments.

Referring to FIG. 7, the surface emitting laser device 203 according to the third exemplary embodiment may provide an oxide layer 240. The oxide layer 240 may include an insulating region 242 and an opening 241. The insulating region 242 may surround the opening 241. For example, the opening 241 may be disposed on the first area (center area) of the light emitting layer 230, and the insulating area 242 may be disposed on the second area (edge area) of the light emitting layer 230. The second region may surround the first region.

The opening 241 may be a passage area through which current flows. The insulating region 242 may be a blocking region that blocks the flow of current. The amount of current supplied from the second electrode 280 to the light emitting layer 230, that is, the current density may be determined by the size of the opening 241. Since the size of the oxide layer 240 is fixed, the size of the opening 241 may be determined by the size of the insulating region 242. That is, as the size of the insulating region 242 increases, the size of the opening 241 decreases, and accordingly, the current density supplied to the light emitting layer 230 may increase. In addition, the opening 241 may be a passage through which the beam generated in the emission layer 230 travels in an upward direction, that is, in a direction of the second reflective layer 250. That is, the divergence angle of the beam of the light emitting layer 230 may vary according to the size of the opening 241.

Opening 241 may include a semiconductor material, such as a Group 3-5 or Group 2-6 compound semiconductor material.

The insulating region 242 may be referred to as an oxide layer or an oxidation layer. The insulating region 242 may include an oxidizing material. The insulating region 242 may be formed of an insulating layer, for example, aluminum oxide (Al ₂ O ₃ ).

The insulating region 242 may be formed by oxidizing the opening 241. For example, the oxide layer 240 is AlGaAs if it contains (aluminum gallium arsenide), the oxide layer 240 is AlGaAs is H ₂ O and the edge is an aluminum oxide of the reaction layer of oxide 240 over the oxidation step of (Al ₂ O of ₃ ) may be formed as an insulating region 242. In addition, a central region that does not react with H ₂ O may be formed as an opening 241 including AlGaAs. During the oxidation process, H ₂ O and AlGaAs penetrated through the side of the oxide layer 240 may be oxidized and converted into aluminum oxide (Al ₂ O ₃ ). Therefore, the penetration depth of H ₂ O varies depending on the thickness of the oxide layer 240, the type or composition of the oxide layer 240, and thus, the size of the insulating region 242 changed to aluminum oxide (Al ₂ O ₃ ) may vary.

According to the embodiment, the light emitted from the light emitting layer 230 may be emitted to the upper region through the opening 241, and the light transmittance of the opening 241 may be excellent compared to the insulating region 242.

The opening 241 may include a plurality of layers. For example, the opening 241 may include a first semiconductor region 241a, a second semiconductor region 241b and a second semiconductor region disposed on the first semiconductor region 241a. It may include a third semiconductor region 241c disposed on the 241b. The first semiconductor region 241a may be in contact with the top surface of the emission layer 230, and the third semiconductor region 241c may be in contact with the bottom surface of the second reflective layer 250, but the embodiment is not limited thereto.

The insulating region 242 may include a plurality of layers. For example, the insulating region 242 may include a first insulating region 242a and a second insulating region 242b disposed on the first insulating region 242a. ) And a third insulating region 24c disposed between the second insulating region 242b. The first insulating region 242a may be in contact with the top surface of the emission layer 230, and the third insulating region 242c may be in contact with the bottom surface of the second reflective layer 250, but is not limited thereto.

The first insulating region 242a of the insulating region 242 may surround the first semiconductor region 241a of the opening 241. The second insulating region 242b of the insulating region 242 may surround the second semiconductor region 241b of the opening 241. The third insulating region 242c of the insulating region 242 may surround the third semiconductor region 241c of the opening 241.

For example, the first insulating region 242a and the first semiconductor region 241a are referred to as a first oxide layer, the second insulating region 242b and the second semiconductor region 241b are referred to as a second oxide layer, and the third The insulating region 242c and the third semiconductor region 241c may be referred to as a third oxide layer. Accordingly, the oxide layer 240 may include a first oxide layer, a second oxide layer disposed on the first oxide layer, and a third oxide layer disposed on the second oxide layer. The embodiment is not limited thereto, and a plurality of oxide layers 240 may be provided.

For example, a first semiconductor film including, for example, a first semiconductor material is formed on the entire region of the first oxide layer, and an edge region of the first semiconductor film is oxidized through an oxidation process to be defined as the first insulating region 242a and is oxidized. An uncentered center region may be defined as the first semiconductor region 241a. For example, a second semiconductor film including, for example, a second semiconductor material is formed on the entire region of the second oxide layer, and an edge region of the second semiconductor film is oxidized through an oxidation process to be defined as the second insulating region 242b and is oxidized. An uncentered center region may be defined as the second semiconductor region 241b. For example, a third semiconductor film including, for example, a third semiconductor material is formed on the entire region of the third oxide layer, and an edge region of the third semiconductor film is oxidized through an oxidation process to be defined as the third insulating region 242c and is oxidized. An uncentered center region may be defined as the third semiconductor region 241c.

According to the third embodiment, the oxide layer 240 is composed of a plurality of layers, for example, the first to third oxide layers, so that the stress stress of the oxide layer generated when the oxide layer is composed of a single layer can be alleviated.

In the first semiconductor region 241a, the second semiconductor region 241b, and the third semiconductor region 241c, the thickness, the concentration, or the size may or may not be the same.

According to the third embodiment, the thickness of each of the first to third semiconductor regions 241a, 241b, and 241c may be the same.

According to the third embodiment, the thickness of the second semiconductor region 241b may be smaller than the thickness of the first semiconductor region 241a or the thickness of the third semiconductor region 241c. For example, the ratio of the thicknesses of the first to third semiconductor regions 241a, 241b, and 241c may be 1: 0.3: 1 to 1: 1: 1. For example, the thickness of each of the first semiconductor region 241a and the third semiconductor region 241c may be about 10 nm, and the thickness of the second semiconductor region 241b may be about 3 nm to about 10 nm.

The thickness of the first semiconductor region 241a may be larger or smaller than the thickness of the third semiconductor region 241c.

As described above, the first semiconductor film is partially oxidized to form the first semiconductor region 241a and the first insulating region 242a, and the second semiconductor film is partially oxidized to form the second semiconductor region 241b and the second. The insulating region 242b may be formed, and the third semiconductor layer may be partially oxidized to form the third semiconductor region 241c and the third insulating region 242c. Therefore, the thickness of the first insulating region 242a is the same as the thickness of the first semiconductor region 241a, the thickness of the second insulating region 242b is the same as the thickness of the second semiconductor region 241b, and the third The thickness of the insulating region 242c may be the same as the thickness of the third semiconductor region 241c.

According to the third embodiment, the concentration of each of the first to third semiconductor regions 241a, 241b, and 241c may be different. In detail, the Al concentration of each of the first to third semiconductor regions 241a, 241b, and 241c may be different. For example, the Al concentration of the second semiconductor region 241b is lower than that of each of the first semiconductor region 241a and the third semiconductor region 241c, and the Al concentration of the first semiconductor region 241a is the third semiconductor region. It may be higher than the Al concentration of (241c).

For example, when each of the first to third semiconductor regions 241a, 241b, and 241c includes AlGaAs, the Al concentration of each of the first semiconductor region 241a and the third semiconductor region 241c is 0.9 or more and 0.99 or less. The Al concentration of the second semiconductor region 241b may be 0.8 or more and 0.9 or less.

In detail, the Al concentration of the first semiconductor region 241a may be 0.99, the Al concentration of the second semiconductor region 241b may be 0.84, and the Al concentration of the third semiconductor region 241c may be 0.98.

In general, the higher the Al concentration, the more easily H ₂ O penetrates into the interior from the side surfaces of the first to third semiconductor films.

In FIG. 7, since the Al concentrations of the first semiconductor region 241a and the third semiconductor region 241c are the same, and the penetration depth of H ₂ O is the same, the first insulating region 242a and the third insulating layer formed as a result of the oxidation are formed. Each of the regions 242c may have the same size. As described above, when the Al concentration (0.99) of the first semiconductor region 241a is higher than the Al concentration (0.98) of the third semiconductor region 241c, the size of the first semiconductor region 241a is third. It may be larger than the size of the semiconductor region 241c. The size may be referred to as the width.

Since the size of each of the first to third insulating regions 242a, 242b, and 242c is determined by the Al concentration of each of the first to third semiconductor regions 241a, 241b, and 241c, as shown in FIG. Each of the first insulating region 242a and the third insulating region 242c having a high concentration may be larger than the size of the second insulating region 242b having a low Al concentration.

The diameter of each of the first to third semiconductor regions 241a, 241b, and 241c may be determined by the size of each of the first to third insulating regions 242a, 242b, and 242c.

Since the size of each of the first insulating region 242a and the third insulating region 242c having a high Al concentration is large, the first semiconductor region 241a and the third insulating layer disposed on the same layer as the first insulating region 242a are provided. The diameter D1 of each of the third semiconductor regions 241c disposed on the same layer as the region 242c is small. Since the size of the second insulating region 242b having a low Al concentration is small, the diameter D2 of the second semiconductor region 241b disposed on the same layer as the second insulating region 242b is large. Therefore, the diameter D2 of the second semiconductor region 241b may be larger than the diameter D1 of each of the first semiconductor region 241a and the third semiconductor region 241c.

From the perspective of the first to third semiconductor regions 241a, 241b, and 241c, the second semiconductor region 241b extends outward from an end of the first semiconductor region 241a or the third semiconductor region 241c. It may protrude. The protruding region of the second semiconductor region 241b may not vertically overlap the first semiconductor region 241a or the third semiconductor region 241c. The protruding regions of the second semiconductor regions 241b may vertically overlap with portions of the first or third insulating regions 242a and 242c.

From the perspective of the first to third insulating regions 242a, 242b, and 242c, the first insulating region 242a or the third insulating region 242c may move inward from the inner end of the second insulating region 242b. Can protrude along. Accordingly, the protruding regions of each of the first and third insulating regions 242a and 242c overlap each other perpendicularly, and the protruding regions of each of the first and third insulating regions 242a and 242c are formed of the second semiconductor region 241b. The protruding region of the first insulating region 242a or the third insulating region 242c may not overlap with the second insulating region 242b.

The outer surfaces of the first to third insulating regions 242a, 242b and 242c may be vertically aligned, and the inner surfaces of the first to third insulating regions 242a, 242b and 242c may not vertically coincide. Side surfaces of the first to third semiconductor regions 241a, 241b, and 241c may not vertically coincide with each other. The side surface of the first semiconductor region 241a is in contact with the inner surface of the first insulating region 242a, and the side surface of the second semiconductor region 241b is in contact with the inner surface of the second insulating region 242b. Side surfaces of the semiconductor region 241c may contact inner surfaces of the third insulating region 242c.

As shown in FIG. 9, when a current flows into the second reflective layer 250, the light emitting layer 230, and the first reflective layer 220, the diameter D2 of the second semiconductor region 241b is defined as the first semiconductor region ( Since it is larger than the diameter D2 of the 241a or the third semiconductor region 241c, the diameter D2 is larger than the diameter D1 of the third semiconductor region 241c after the current passes through the third semiconductor region 241c. Part of the current flows in the first semiconductor region 241a along the vertical direction, and the other part of the current flows in the in-plane direction of the second semiconductor region 241b. , Can flow along the outward direction. As a result, the current density can be suppressed by preventing the current from dense in the opening 241.

As shown in FIG. 8A, the band gaps of the first to third semiconductor regions 241a, 241b, and 241c may be different. The band gap may vary depending on the Al concentration included in the first to third semiconductor regions 241a, 241b, and 241c.

For example, as the Al concentration increases, the band gap may increase. As described above, since the Al concentration of the second semiconductor region 241b is smaller than the Al concentration of the first semiconductor region 241a or the Al concentration of the third semiconductor region 241c, the band of the second semiconductor region 241b. The gap may be smaller than the band gap of the first semiconductor region 241a or the band gap of the third semiconductor region 241c.

Accordingly, the second semiconductor region 241b having a small band gap is disposed between the first semiconductor region 241a and the third semiconductor region 241c having a large band gap, thereby forming the first to third semiconductor regions of the oxide layer 240. Current concentration at 241a, 241b and 241c can be relaxed and the diffraction effect can be reduced. In addition, the shrinkage stress is alleviated by such a sandwich structure (the structure in which the second semiconductor region 241b having a small band gap is disposed between the first semiconductor region 241a and the third semiconductor region 241c having a large band gap). The deterioration of the laser beam emission characteristics can be prevented due to the bending characteristics of the surface-emitting laser element.

As shown in FIG. 8B, In may be added to the second semiconductor region 241b to make the band gap relatively smaller. As In is added, the band gap may be reduced. An In concentration added to the second semiconductor region 241b may be 0.05 or more and 0.18 or less, but is not limited thereto. For example, the In concentration added to the second semiconductor region 241b may be 0.1.

As shown in FIG. 8A, when In is added to the second semiconductor region 241b as compared with the case where In is not added to the second semiconductor region 241b, the band gap is reduced to a predetermined width ( Can be as small as Δd).

Therefore, when In is added to the second semiconductor region 241b to further reduce the band gap, as shown in FIG. 9, the first carrier, that is, the hole generated in the second reflective layer 250, is formed in the third semiconductor region. The second semiconductor region 241b may move along the transverse direction via 241c. Accordingly, the current may not only flow to the light emitting layer 230 via the first semiconductor region 241a along the vertical direction in the second semiconductor region 241b but may also flow along the transverse direction in the second semiconductor region 241b. . That is, since the current is distributed in the vertical direction and the lateral direction in the second semiconductor region 241b, the current density phenomenon in which the current is concentrated along the aperture edge can be alleviated.

(Example 4)

FIG. 10 is a cross-sectional view of the surface-emitting laser device according to the fourth embodiment, FIG. 11 shows a band gap which varies depending on whether In is added in the fourth embodiment, and FIG. 12 shows the current density according to the fourth embodiment. Shows.

FIG. 10 is an enlarged view of an opening 241 and an insulating region 242 of the surface light emitting laser device illustrated in FIG. 3A.

The fourth embodiment may be the same as the first to third embodiments except for the opening 241 and the insulating region 242. In particular, in the fourth exemplary embodiment, the thicknesses, concentrations, or sizes of the first to third semiconductor regions 241a, 241b, and 241c and the first to third insulating regions 242a, 242b, and 242c of the oxide layer 240 may have a third thickness. It differs from an Example.

In the fourth embodiment, components having the same structure, shape, and / or function as those in the first to third embodiments are denoted by the same reference numerals and detailed description thereof will be omitted. Technical matters omitted in the following description can be easily understood from the above-described first to third embodiments.

Referring to FIG. 10, the surface emitting laser device 204 according to the fourth embodiment may provide an oxide layer 240. The oxide layer 240 may include an insulating region 242 and an opening 241.

The oxide layer 240 may be composed of a plurality of layers. That is, the insulating region 242 may be composed of a plurality of insulating regions, and the opening 241 may be composed of a plurality of semiconductor regions.

For example, the oxide layer 240 may include first to third oxide layers. The first oxide layer may be disposed on the emission layer 230, the second oxide layer may be disposed on the first oxide layer, and the third oxide layer may be disposed on the second oxide layer. The first oxide layer may be in contact with the top surface of the emission layer 230, but is not limited thereto. The third oxide layer may be in contact with the bottom surface of the second reflective layer 250, but is not limited thereto.

The opening 241 may include a first semiconductor region 241a, a second semiconductor region 241b, and a third semiconductor region 241c. The insulation region 242 may include a first insulation region 242a, a second insulation region 242b, and a third insulation region 242c.

The first semiconductor region 241a and the first insulating region 242a may be disposed on the same layer to be defined as a first oxide layer. The second semiconductor region 241b and the second insulating region 242b may be disposed on the same layer to be defined as a second oxide layer. The third semiconductor region 241c and the third insulating region 242c may be disposed on the same layer to be defined as a third oxide layer.

According to the fourth embodiment, since the oxide layer 240 is composed of a plurality of layers, for example, the first to third oxide layers, the shrinkage stress of the oxide layer generated when the oxide layer is composed of a single layer can be alleviated.

In the first semiconductor region 241a, the second semiconductor region 241b, and the third semiconductor region 241c, the thickness, the concentration, or the size may or may not be the same.

According to the fourth embodiment, each of the first to third semiconductor regions 241a, 241b, and 241c may have the same thickness.

According to the fourth embodiment, the thickness of the first semiconductor region 241a or the thickness of the third semiconductor region 241c may be smaller than the thickness of the second semiconductor region 241b. For example, the ratio of the thicknesses of the first to third semiconductor regions 241a, 241b, and 241c may be 0.3: 1: 0.3 to 1: 1: 1. For example, the thickness of each of the second semiconductor regions 241b may be 10 nm, and the thickness of the first semiconductor region 241a or the third semiconductor region 241c may be about 3 nm to about 10 nm.

According to the fourth embodiment, the concentration of each of the first to third semiconductor regions 241a, 241b, and 241c may be different. For example, the Al concentration of the second semiconductor region 241b is higher than the Al concentration of each of the first semiconductor region 241a and the third semiconductor region 241c, and the Al concentration of the first semiconductor region 241a is the third semiconductor region. It may be the same as or different from the Al concentration of 241c.

For example, when each of the first to third semiconductor regions 241a, 241b, and 241c includes AlGaAs, the Al concentration of each of the first semiconductor region 241a and the third semiconductor region 241c is 0.8 or more and less than 0.9, The Al concentration of the second semiconductor region 241b may be 0.9 or more and 0.99 or less.

In detail, the Al concentration of the first semiconductor region 241a may be 0.84, the Al concentration of the second semiconductor region 241b may be 0.99, and the Al concentration of the third semiconductor region 241c may be 0.84.

In general, the higher the Al concentration, the more easily H ₂ O penetrates into the interior from the side surfaces of the first to third semiconductor films.

In FIG. 10, since the Al concentrations of the first semiconductor region 241a and the third semiconductor region 241c are the same, and the penetration depth of H ₂ O is the same, the first insulating region 242a and the third insulating layer formed as a result of oxidation are obtained. Each of the regions may have the same size. As described above, when the Al concentration (0.99) of the second semiconductor region 241b is higher than the Al concentration (0.84) of each of the first and third semiconductor regions 241a and 241c, the second semiconductor region 241b. ) May be larger than the size of each of the first and third semiconductor regions 241a and 241c.

When the outer surfaces of the first to third insulating regions 242a, 242b, and 242c vertically coincide with each other, the inner surface of the second semiconductor region 241b may be formed in each of the first and third semiconductor regions 241a and 241c. It may protrude in the inward direction from the side.

Since the size of each of the first to third insulating regions 242a, 242b, and 242c is determined by the Al concentration of each of the first to third semiconductor regions 241a, 241b, and 241c, as shown in FIG. Each size of the second insulating region 242b having a high concentration may be larger than that of the first or third insulating regions 242a and 242c having a low Al concentration.

The diameter of each of the first to third semiconductor regions 241a, 241b, and 241c may be determined by the size of each of the first to third insulating regions 242a, 242b, and 242c.

Since the size of each of the second insulating regions 242b having a high Al concentration is large, the diameter D1 of the second semiconductor region 241b is small. Since the size of the first or third insulating regions 242a and 242c having a low Al concentration is small, the diameter D2 of the first or semiconductor regions 241a and 241c is large. Therefore, the diameter D2 of the first or semiconductor regions 241a and 241c may be larger than the diameter D1 of the second semiconductor region 241b.

From the perspective of the first to third semiconductor regions 241a, 241b and 241c, the first or semiconductor regions 241a and 241c may protrude in an outward direction from an end of the second semiconductor region 241b. Therefore, the protruding region of the first semiconductor region 241a and the protruding region of the third semiconductor region 241c overlap vertically, and the protruding regions of the first or semiconductor regions 241a and 241c are the second semiconductor region 241b. May not overlap vertically with the. The protruding regions of the first or semiconductor regions 241a and 241c may vertically overlap with a portion of the second insulating region 242b.

In view of the first to third insulating regions 242a, 242b, and 242c, the second insulating region 242b may protrude along an inner direction from an inner end of the first or third insulating regions 242a and 242c. Can be. The protruding regions of the second insulating regions 242b may not vertically overlap with the first or third insulating regions 242a and 242c. The protruding regions of the second insulating regions 242b may vertically overlap the protruding regions of the first or semiconductor regions 241a and 241c.

The side surface of the first semiconductor region 241a is in contact with the inner surface of the first insulating region 242a, and the side surface of the second semiconductor region 241b is in contact with the inner surface of the second insulating region 242b. Side surfaces of the semiconductor region 241c may contact inner surfaces of the third insulating region 242c.

As shown in FIG. 11A, the band gaps of the first to third semiconductor regions 241a, 241b, and 241c may be different. The band gap may vary depending on the Al concentration included in the first to third semiconductor regions 241a, 241b, and 241c.

For example, as the Al concentration increases, the band gap may increase. As described above, since the Al concentration of the first or semiconductor regions 241a and 241c is smaller than the Al concentration of the second semiconductor region 241b, the band gap of the Al concentration of the first or semiconductor regions 241a and 241c is It may be smaller than the band gap of the second semiconductor region 241b.

Therefore, the first or the semiconductor regions 241a and 241c having a small band gap are disposed between the second semiconductor regions 241b having a large band gap, whereby the first to third semiconductor regions 241a and 241b of the oxide layer 240 are formed. The current concentration at 241c can be relaxed and the diffraction effect can be reduced. In addition, the shrinkage stress is alleviated by such a sandwich structure (a structure in which the first or the semiconductor regions 241a and 241c having a small band gap are disposed between the second semiconductor regions 241b with a large band gap) and thus the surface emitting laser device. Deterioration of the laser beam emission characteristic can be prevented due to the bending characteristic of the.

As shown in FIG. 11B, In may be added to the first or semiconductor regions 241a and 241c to make the band gap relatively smaller. As In is added, the band gap may be reduced. The In concentration added to the first or semiconductor regions 241a and 241c may be 0.05 or more and 0.18 or less, but is not limited thereto. For example, the In concentration added to the first or semiconductor regions 241a and 241c may be 0.1.

As shown in FIG. 11A, when In is not added to the first or semiconductor regions 241a and 241c, as shown in FIG. 11B, In is added to the first or semiconductor regions 241a and 241c. The gap can be made smaller by a predetermined width Δd.

Therefore, when In is added to the first or semiconductor regions 241a and 241c so that the band gap becomes smaller, as shown in FIG. 12, holes generated in the second reflective layer 250 are transferred to the third semiconductor region 241c. ) May be moved along the lateral direction in the first semiconductor region 241a. Accordingly, the current may not only flow to the light emitting layer 230 along the vertical direction, but may also flow along the transverse direction in the first or semiconductor regions 241a and 241c. That is, since current is distributed in the vertical direction and the transverse direction in the first or semiconductor regions 241a and 241c, the current density phenomenon in which the current is concentrated along the aperture edge can be alleviated.

(Example 5)

FIG. 13 is a cross-sectional view of the surface emitting laser device according to the fifth embodiment, FIG. 14 shows the flow of holes in the fifth embodiment, and FIG. 15 shows the degree of current density according to the fifth embodiment.

FIG. 13 is an enlarged view of an opening 241 and an insulating region 242 of the surface light emitting laser device illustrated in FIG. 3A.

The fifth embodiment may be the same as the first to fourth embodiments except for the opening 241 and the insulating region 242. In particular, the shapes of the first to third semiconductor regions 241a, 241b and 241c and the first to third insulating regions 242a, 242b and 242c of the oxide layer 240 are different from those of the third embodiment in the fifth embodiment. Do.

In the fifth embodiment, components having the same structure, shape, and / or function as those in the first to third embodiments are denoted by the same reference numerals and detailed description thereof will be omitted. Technical matters omitted in the following description can be easily understood from the above-described first to fourth embodiments.

Referring to FIG. 13, the surface emitting laser device 205 according to the fifth embodiment may provide an oxide layer 240. The oxide layer 240 may include an insulating region 242 and an opening 241.

The oxide layer 240 may be composed of a plurality of layers. That is, the insulating region 242 may be composed of a plurality of insulating regions, and the opening 241 may be composed of a plurality of semiconductor regions.

For example, the oxide layer 240 may include first to third oxide layers. The first oxide layer may be disposed on the emission layer 230, the second oxide layer may be disposed on the first oxide layer, and the third oxide layer may be disposed on the second oxide layer. The first oxide layer may be in contact with the top surface of the emission layer 230, but is not limited thereto. The third oxide layer may be in contact with the bottom surface of the second reflective layer 250, but is not limited thereto.

According to the fifth embodiment, the Al concentration of the second semiconductor region 241b is lower than the Al concentration of each of the first semiconductor region 241a and the third semiconductor region 241c, and the Al concentration of the first semiconductor region 241a is reduced. May be higher than the Al concentration of the third semiconductor region 241c.

For example, when each of the first to third semiconductor regions 241a, 241b, and 241c includes AlGaAs, the Al concentration of each of the first semiconductor region 241a and the third semiconductor region 241c is 0.9 or more and 0.99 or less. The Al concentration of the second semiconductor region 241b may be 0.8 or more and 0.9 or less.

The higher the Al concentration, the deeper the penetration depth of H ₂ O. Therefore, the size of the first or semiconductor regions 241a and 241c having a high Al concentration may be smaller than that of the second semiconductor region 241b having a low Al concentration.

Since the size of each of the first to third insulating regions 242a, 242b, and 242c is determined by the Al concentration of each of the first to third semiconductor regions 241a, 241b, and 241c, the first or third Al concentration is high. Each of the third insulating regions 242a and 242c may have a size larger than that of the second insulating region 242b having a low Al concentration.

The diameter of each of the first to third semiconductor regions 241a, 241b, and 241c may be determined by the size of each of the first to third insulating regions 242a, 242b, and 242c.

The diameter of the second semiconductor region 241b may be larger than the diameter of each of the first semiconductor region 241a and the third semiconductor region 241c.

From the perspective of the first to third semiconductor regions 241a, 241b, and 241c, the second semiconductor region 241b extends outward from an end of the first semiconductor region 241a or the third semiconductor region 241c. It may protrude. Therefore, the protruding region of the second semiconductor region 241b may not overlap with the first semiconductor region 241a or the third semiconductor region 241c.

From the perspective of the first to third insulating regions 242a, 242b, and 242c, the first insulating region 242a or the third insulating region 242c may move inward from the inner end of the second insulating region 242b. Can protrude along. Accordingly, the protruding region of the first insulating region 242a and the protruding region of the third insulating region 242c vertically overlap each other, and the protruding region of the first insulating region 242a or the third insulating region 242c is formed in a first direction. 2 may not overlap vertically with the insulating region 242b.

Meanwhile, according to the fifth embodiment, the first oxide layer and / or the third oxide layer may include an Al concentration varying in grading. For example, the Al concentration of the first oxide layer may increase linearly or nonlinearly in the direction of the second reflective layer 250 in the first emission layer 230. For example, the Al concentration of the third oxide layer may increase linearly or nonlinearly toward the second reflective layer 250 in the emission layer 230.

When the oxidation process of the first to third oxide layers having such an Al concentration distribution is performed, as the Al concentration increases in the first or third oxide layer, the first insulating region 242a is formed in the first oxide layer. ) And the inner end of the third insulating region 242c formed from the third oxide layer are obstructed regions 241_1 and 241_2 protruding gradually inward from the light emitting layer 230 toward the second reflective layer 250. ) May be formed. That is, the shape of the first oxide layer gradually protrudes inward from the light emitting layer 230 toward the second reflective layer 250 in the inner region of the first insulating region 242a in contact with the first semiconductor region 241a. It may have a first disturbance area (241_1) having. The third oxide layer has a shape that gradually protrudes inwardly toward the inner side of the third insulating region 242c in contact with the third semiconductor region 241c toward the second reflective layer 250 in the light emitting layer 230. 2 interfering region 241_2 may be formed.

As shown in FIGS. 14 and 15, holes generated in the second reflective layer 250 are formed through the third semiconductor region 241c by the second interference region 242_2 of the third insulating region 242c. 2 Movement to the semiconductor region 241b can be suppressed. In addition, the holes moved to the second semiconductor region 241b are suppressed from moving to the light emitting layer 230 via the first semiconductor region 241a by the first disturbing region 242_1 of the first insulating region 242a. Can be. In addition, holes moved to the second semiconductor region 241b may be dispersed and moved in the horizontal direction as well as in the vertical direction. As such, since the movement of holes is suppressed at the edge of the opening 241 of the oxide layer 240 and the holes are dispersed in the vertical direction and the transverse direction, current density is prevented and the divergence angle of the beam does not change, so the output of the precise laser beam is achieved. This is possible.

Meanwhile, the interference regions 241_1 and 241_2 according to the fifth embodiment may also be formed in the second semiconductor region 241b described in the fourth embodiment (FIGS. 10 to 12). To this end, in the fourth embodiment, the inner end of the second insulating region 242b surrounding the second semiconductor region 241b gradually obstructs the inner side toward the second reflective layer 250 from the light emitting layer 230. It can have an area.

(Manufacturing method)

Hereinafter, a method of manufacturing a surface emitting laser device according to an embodiment will be described with reference to FIGS. 16A to 20B. Meanwhile, the following manufacturing method will be described with reference to the manufacturing method of the first embodiment, but the manufacturing method is not only applied to the manufacturing of the first embodiment, but may also be applied to the manufacturing methods of the second to fifth embodiments.

First, as shown in FIG. 16A, a light emitting structure including a first reflective layer 220, a light emitting layer 230, and a second reflective layer 250 is formed on a substrate 210.

The substrate 210 may be formed of a material suitable for growth of a semiconductor material or a carrier wafer, may be formed of a material having excellent thermal conductivity, and may include a conductive substrate or an insulating substrate.

For example, when the substrate 210 is a conductive substrate, a metal having excellent electrical conductivity may be used, and a GaAs substrate having high thermal conductivity because it must be able to sufficiently dissipate heat generated when the surface emitting laser device 201 is operated. Alternatively, a metal substrate may be used or a silicon (Si) substrate may be used.

In addition, when the substrate 210 is a non-conductive substrate, an AlN substrate, a sapphire (Al ₂ O ₃ ) substrate, or a ceramic substrate may be used.

In addition, in the exemplary embodiment, a substrate of the same type as the first reflective layer 220 may be used as the substrate 210. For example, when the substrate 210 is a GaAs substrate of the same type as the first reflective layer 220, the lattice constant coincides with the first reflective layer 210, so that a defect such as lattice mismatch does not occur in the first reflective layer 220. Can be.

Next, a first reflective layer 220 may be formed on the substrate 210, and FIG. 16B is an enlarged cross-sectional view of the second region B2 of the surface light emitting laser device according to the embodiment shown in FIG. 16A.

Hereinafter, a surface light emitting laser device according to an exemplary embodiment will be described with reference to FIGS. 16A and 16B.

The first reflective layer 220 may be grown using a chemical vapor deposition method (CVD) or a molecular beam epitaxy (MBE) or a sputtering or hydroxide vapor phase epitaxy (HVPE).

The first reflective layer 220 may be doped with a first conductivity type. For example, the first conductivity type dopant may include an n type dopant such as Si, Ge, Sn, Se, Te, or the like.

The first reflective layer 220 may include a gallium-based compound, for example, AlGaAs, but is not limited thereto. The first reflective layer 220 may be a distributed bragg reflector (DBR). For example, the first reflective layer 220 may have a structure in which layers including materials having different refractive indices are alternately stacked at least once.

For example, as shown in FIG. 16B, the first reflective layer 220 is disposed on the first group first reflective layer 221 and the first group first reflective layer 221 disposed on the substrate 210. The second group first reflective layer 222 may be included.

The first group first reflective layer 221 and the second group first reflective layer 222 may include a plurality of layers including a semiconductor material having a compositional formula of Al _x Ga _(1-x) As (0 <x <1). If the Al in each layer increases, the refractive index of each layer may decrease, and if the Ga increases, the refractive index of each layer may increase.

In addition, as shown in FIG. 16B, the first group first reflective layer 221 and the second group first reflective layer 222 may also be formed of a single layer or a plurality of layers, respectively. For example, the first group first reflective layer 221 may include about 30-40 pairs of the first group first-first layer 221a and the first group first-second layer 221b. have. In addition, the second group first reflective layer 222 may also include about 5 to 15 pairs of the second group first-first layer 222a and the second group first-second layer 222b.

Next, the light emitting layer 230 may be formed on the first reflective layer 220.

As shown in FIG. 16B, the light emitting layer 230 may include an active layer 232, a first cavity 231 disposed below the active layer 232, and a second cavity 233 disposed above the active layer 232. The light emitting layer 230 of the embodiment may include both the first cavity 231 and the second cavity 233, or may include only one of them.

 The active layer 232 may include a quantum well layer 232a and a quantum wall layer 232b using a compound semiconductor material of a group III-V element. The active layer 232 may be formed in a 1 to 3 pair structure such as InGaAs / AlxGaAs, AlGaInP / GaInP, AlGaAs / AlGaAs, AlGaAs / GaAs, GaAs / InGaAs, but is not limited thereto. Dopants may not be doped in the active layer 232.

The first cavity 231 and the second cavity 233 may be formed of Al _y Ga _(1-y) As (0 <y <1) material, but is not limited thereto. For example, the first cavity 231 and the second cavity 233 may each include a plurality of layers made of Al _y Ga _(1-y) As.

For example, the first cavity 231 may include a first-first cavity layer 231a and a first-second cavity layer 231b. In addition, the second cavity 233 may include a 2-1 cavity layer 233a and a 2-2 cavity layer 233b.

Next, a plurality of semiconductor films 240a, 240b, and 240c for forming the oxide layer 240 may be formed on the emission layer 230. The semiconductor films 240a, 240b, and 240c may include an AlGa-based material.

Next, a second reflective layer 250 may be formed on the AlGa-based layer 241a.

The second reflective layer 250 may include a gallium-based compound, for example AlGaAs. For example, each layer of the second reflective layer 250 may include AlGaAs, and in detail, may be formed of a semiconductor material having a compositional formula of Al _x Ga _(1-x) As (0 <x <1). .

The second reflective layer 250 may be doped with a second conductivity type dopant. For example, the second conductivity type dopant may be a p-type dopant such as Mg, Zn, Ca, Sr, or Ba. Meanwhile, the first reflective layer 220 may be doped with a p-type dopant, and the second reflective layer 250 may be doped with an n-type dopant.

The second reflective layer 250 may also be a distributed Bragg reflector (DBR). For example, the second reflective layer 250 may have a structure in which a plurality of layers including materials having different refractive indices are alternately stacked at least once.

For example, the second reflective layer 250 is spaced apart from the first group second reflective layer 251 and the first group second reflective layer 251 disposed adjacent to the light emitting layer 230 from the light emitting layer 230. The second group second reflective layer 252 may be disposed.

In addition, the first group second reflecting layer 251 and the second group second reflecting layer 252 may be formed of a single layer or a plurality of layers, respectively. For example, the first group second reflective layer 251 may include about 1 to 5 pairs of the first group 2-1 layer 251a and the first group 2-2 layer 251b. In addition, the second group second reflective layer 252 may also include about 5 to 15 pairs of the second group 2-1 layer 252a and the second group 2-2 layer 252b. .

Next, FIG. 17A is an enlarged view of the first region C1 of the surface light emitting laser device according to the embodiment, and FIG. 17B is a cross-sectional view taken along line A1-A2 of the surface light emitting laser device according to the embodiment shown in FIG. 17A.

17B, the light emitting structure may be etched using a predetermined mask 300 to form a mesa region M. Referring to FIG. In this case, the mesa may be etched from the second reflective layer 250 to the plurality of semiconductor layers 240a, 240b, and 240c and the emission layer 230, and may be mesa etched to a part of the first reflective layer 220. In mesa etching, a plurality of semiconductor layers 240a, 240b, and 240c and a light emitting layer 230 may be removed from the second reflective layer 250 in the peripheral region by an inductively coupled plasma (ICP) etching method. It can be etched with this slope.

 Next, FIG. 18A is an enlarged view of the first region C1 of the surface light emitting laser device according to the embodiment, and FIG. 18B is a cross-sectional view taken along line A1-A2 of the surface light emitting laser device according to the embodiment shown in FIG. 18A.

As shown in FIG. 18B, the first to third insulating regions (242a, 242b of FIGS. 7 to 15, modified by reacting with H ₂ O in the plurality of semiconductor films 240a, 240b, and 240c by a wet oxidation process) are modified. Openings 241 including an insulating region 242 including 242c and first to third semiconductor regions (241a, 241b, and 241c of FIGS. 7 to 15) including a semiconductor material without reacting with H ₂ O ) May be included. In the insulating region 242, aluminum oxide (Al), which is changed by H ₂ O, penetrates from the outer surfaces of the plurality of semiconductor films 240a, 240b, and 240c and reacts with Al included in the semiconductor films 240a, 240b, and 240c. ₂ O ₃ ). The opening is a region that can not be H ₂ O from penetrating the interior of the plurality of semiconductor films (240a, 240b, 240c), H 2 O is not react with Al, so it is possible to include a semiconductor material, that is AlGa-based material.

In addition, the embodiment may change the edge region of the AlGa based layer into the insulating region 242 through ion implantation, but is not limited thereto. During ion implantation, photons may be supplied with energy of 300 keV or more.

After the reaction process described above, a conductive opening 241 may be disposed in the central region of the oxide layer 240, and a non-conductive insulating region 242 may be disposed in the edge region.

 One of the technical problems of the embodiment is a surface emitting laser device capable of preventing the problem of the beam pattern splitting due to a higher mode shift even when a high current is applied or the aperture size is increased. And to provide a light emitting device comprising the same.

Next, FIG. 19A is an enlarged view of the first region C1 of the surface light emitting laser device according to the embodiment, and FIG. 19B is a cross-sectional view taken along line A1-A2 of the surface light emitting laser device according to the embodiment shown in FIG. 19A.

As shown in FIG. 19B, a passivation layer 270 may be formed on an upper surface of the light emitting structure. The passivation layer 270 may include at least one of polymide, silica (SiO ₂ ), or silicon nitride (Si ₃ N ₄ ).

The passivation layer 270 may expose a portion of the second reflective layer 250 to be electrically connected to the second electrode 280 formed thereafter.

Next, FIG. 20A is an enlarged view of a first area portion C1 of the surface light emitting laser device according to the embodiment, and FIG. 20B is a cross-sectional view along the line A1-A2 of the surface light emitting laser device according to the embodiment shown in FIG. 20A. .

According to an embodiment, the contact electrode 282 may be formed on the second reflective layer 250 of FIG. 20B, and a central region between the contact electrode 282 may correspond to the opening 241. The contact electrode 282 may improve ohmic contact with the second reflective layer 250.

Next, a pad electrode 284 may be formed in electrical contact with the contact electrode 282, and the pad electrode 284 may be extended to the upper portion of the passivation layer 270 to receive current from the outside. .

The contact electrode 282 and the pad electrode 284 may be made of a conductive material. For example, the contact electrode 282 and the pad electrode 284 include at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). It can be formed into a single layer or a multi-layer structure.

Next, a first electrode 215 may be disposed under the substrate 210. Before disposing the first electrode 215, a portion of the bottom surface of the substrate 210 may be removed through a predetermined grinding process to improve heat dissipation efficiency. The first electrode 215 may be made of a conductive material, for example, metal. For example, the first electrode 215 may include at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). It may be formed into a structure.

The semiconductor device including the surface-emitting laser device described above may be a laser diode, and the two reflective layers may act as a resonator. At this time, holes and a second carrier, that is, electrons, are supplied to the active layer from the first reflective layer 220 of the first conductivity type and the second reflective layer 250 of the second conductivity type, and the light emitted from the emission layer 230 is resonator. When reflected and amplified therein and reaches a threshold current, the light may be emitted to the outside through the opening 241 described above.

The light emitted from the surface emitting laser device according to the embodiment may be light of a single wavelength and a single phase, and a single wavelength region may vary according to the composition of the first reflective layer 220, the second reflective layer 250, and the light emitting layer 230. Can be.

(Example 6)

21 is a cross-sectional view of the surface emitting laser device according to the sixth embodiment.

The surface emitting laser device according to the first to fifth embodiments may be applied to the surface emitting laser device of the flip chip type shown in FIG. 21.

21 is another cross-sectional view of the surface emitting laser device according to the embodiment.

In addition to the vertical type, the surface emitting laser device according to the exemplary embodiment may have a flip chip shape in which the directions of the first electrode 215 and the second electrode 280 are the same as in FIG.

For example, as shown in FIG. 21, the surface-emitting laser device according to another embodiment may include a first electrode 215, a substrate 210, a first reflective layer 220, an active region 230, an aperture region 240, One or more of the second reflective layer 250, the second electrode 280, the first passivation layer 271, the second passivation layer 272, and the anti-reflective layer 290 may be included. In this case, the reflectance of the second reflecting layer 250 may be designed to be higher than that of the first reflecting layer 220.

In this case, the first electrode 215 may include a first contact electrode 216 and a first pad electrode 217, and may be disposed on the first reflective layer 220 exposed through a predetermined mesa process. The 216 may be electrically connected, and the first pad electrode 217 may be electrically connected to the first contact electrode 216.

The first electrode 215 may be made of a conductive material, for example, metal. For example, the first electrode 215 may include at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). It may be formed into a structure.

When the first reflective layer 220 is an n-type reflective layer, the first electrode 215 may be an electrode for the n-type reflective layer.

Next, the second electrode 280 may include a second contact electrode 282 and a second pad electrode 284, and the second contact electrode 282 is electrically connected to the second reflective layer 250. The second pad electrode 284 may be electrically connected to the second contact electrode 282.

When the second reflective layer 250 is a p-type reflective layer, the second electrode 280 may be an electrode for the p-type reflective layer.

Technical features of the surface-emitting laser device according to the above-described embodiment may be applied to the second electrode 280.

For example, there is a technical effect of providing a surface emitting laser device having a highly reliable second electrode structure and a light emitting device including the same.

For example, the second electrode 280 may include a first barrier layer 282b1 having a Ni layer and a second barrier layer 282b2 having a Ti layer. At this time, the second barrier layer 282b2 including the Ti layer is in a state of tensile stress, and the first barrier layer 282b1 including the Ni layer is controlled in a state of compressive stress, thereby controlling the first barrier layer 282b1 and the first barrier layer. The surface-emitting laser device having a highly reliable electrode structure even in a high current density state by preventing the occurrence of internal stress in the barrier layer 282b including the two barrier layers 282b2 and light emission including the same There is a technical effect that can provide a device.

The first insulating layer 271 and the second insulating layer 272 may be made of an insulating material, for example, may be made of nitride or oxide, and may be, for example, polyimide or silica (SiO ₂ ). Or silicon nitride (Si ₃ N ₄ ).

The embodiment has a technical effect of providing a surface emitting laser device having a highly reliable electrode structure and a light emitting device including the same.

In addition, the embodiment can provide a surface-emitting laser device and a light emitting device including the same that can solve the optical problem that the beam pattern of the exit beam is split or the divergence angle of the beam is increased. There is a technical effect.

In addition, the embodiment has a technical effect that can provide a surface emitting laser device and a light emitting device including the same that can improve the ohmic characteristics.

(Mobile terminal)

22 is a perspective view of a mobile terminal to which a surface emitting laser device is applied according to an embodiment.

The vertical surface emitting laser device and the flip surface emitting laser device shown in FIG. 21 according to the first to fifth embodiments may be applied to the mobile terminal shown in FIG.

As illustrated in FIG. 22, the mobile terminal 1500 of the embodiment may include a camera module 1520, a flash module 1530, and an auto focusing device 1510 provided at a rear surface thereof. Here, the auto focus device 1510 may include one of the packages of the surface emitting laser device according to the above-described embodiment as a light emitting layer.

The flash module 1530 may include a light emitting device that emits light therein. The flash module 1530 may be operated by camera operation of a mobile terminal or control of a user.

The camera module 1520 may include an image capturing function and an auto focus function. For example, the camera module 1520 may include an auto focus function using an image.

The auto focus device 1510 may include an auto focus function using a laser. The auto focus device 1510 may be mainly used in a condition where the auto focus function using the image of the camera module 1520 is degraded, for example, in a proximity or a dark environment of 10 m or less. The auto focus device 1510 may include a light emitting layer including the surface emitting laser device of the above-described embodiment, and a light receiving unit for converting light energy such as a photodiode into electrical energy.

The foregoing detailed description should not be construed as limiting in all respects, but should be considered as illustrative. The scope of the embodiments should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the embodiments are included in the scope of the embodiments.

201: surface emitting laser device
210: substrate
215: first electrode
220: first reflective layer
221: first group first reflective layer
221a: first group first-first layer
221b: first group 1-2 layers
222: second group first reflective layer
222a: second group first-first layer
222b: second group 1-2 layers
230: light emitting layer
231: first cavity layer
231a: 1-1st cavity layer
231b: 1-2th cavity layer
232: active layer
232a: quantum well
232b: a quantum barrier
233: second cavity layer
233a: 2-1st cavity layer
233b: Second-2 cavity layer 233b
240: oxide layer
241: opening
241a, 241b, and 241c: semiconductor region
241_1, 241_2: obstruction
242: insulation area
242a, 242b, 242c: insulation region
250: second reflective layer
251: First group second reflective layer
251a: first group 2-1 layers
251b: layer 2-2, first group
252: second group second reflective layer
252a: second group second-2-1
252b: second group second-2 layers
270: passivation layer
280: second electrode
282: contact electrode
284: pad electrode
300: mask
E: light emitting layer
E1, E2, E3: Emitter
M: mesa area
n, N1, N2: refractive index
P: Pad part
D1, D2: Diameter

Claims (15)

Board;
A first reflective layer disposed on the substrate;
An active layer disposed on the first reflective layer;
An oxide layer disposed on the active layer and including an aperture and an insulating region;
A second reflective layer disposed on the oxide layer;
The opening is,
A first semiconductor region;
A second semiconductor region on the first semiconductor region; And
And a third semiconductor region on the second semiconductor region,
The first to third semiconductor regions include Al,
The Al concentration of the second semiconductor region is lower than the Al concentration of the first or third semiconductor region. The method of claim 1,
The Al concentration of the first semiconductor region is the same as the Al concentration of the third semiconductor region. The method of claim 1,
And the second semiconductor region further comprises In. The method of claim 1,
The thickness of the second semiconductor region is less than the thickness of the first or third semiconductor region. The method of claim 4, wherein
The ratio of the thicknesses of the first to third semiconductor regions is 1: 0.3: 1 to 1: 1: 1. The method of claim 4, wherein
The thickness of the second semiconductor region is 3nm to 100nm surface light emitting laser device. The method of claim 1,
The diameter of the second semiconductor region is greater than the diameter of the first or third semiconductor region. The method of claim 1,
The insulating region,
A first insulating region surrounding the first semiconductor region;
A second insulating region disposed on the first insulating region and surrounding the second semiconductor region; And
And a third insulating region disposed on the second insulating region and surrounding the third semiconductor region. The method of claim 8,
The second semiconductor region has a first protruding region protruding in an outward direction from an end of the first or third semiconductor region,
And the first protruding region vertically overlaps a part of the first or third insulating region. The method of claim 9,
The first or third insulating region has a second protruding region protruding inward from the inner end of the second insulating region,
And the second protruding region overlaps the first protruding region vertically. The method of claim 8,
And at least one semiconductor region of the first and third semiconductor regions includes an Al concentration of varying grading. The method of claim 11,
The Al concentration is increased in the direction of the second reflective layer from the active layer. The method of claim 11,
And an inner end portion of the insulating region surrounding the at least one semiconductor region has an obstructing region that gradually protrudes inward toward the second reflective layer from the active layer. Board;
A first reflective layer disposed on the substrate;
An active layer disposed on the first reflective layer;
An oxide layer disposed on the active layer and including an aperture and an insulating region;
A second reflective layer disposed on the oxide layer;
The opening is,
A first semiconductor region on the active layer;
A second semiconductor region on the first semiconductor region; And
And a third semiconductor region on the second semiconductor region,
The first to third semiconductor regions include Al,
The Al concentration of the second semiconductor region is higher than the Al concentration of the first or third semiconductor region. A light emitting device comprising the surface light emitting laser element of any one of claims 1 to 14.

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