KR20180067361A - Gas sensor, fabricating method for gas sensor, gas sensing device - Google Patents

Abstract

A gas sensor disclosed in an embodiment includes: a support member having a first recess; a light emitting element on a first region of the support member; and a first sensor unit is disposed on a second region of the support member and the light emitting element includes a first conductive semiconductor layer, a second conductive semiconductor layer, and a light emitting structure having an active layer between the first conductive semiconductor layer and the second conductive semiconductor layer. The first sensor unit includes: a second sensor electrode disposed in the first recess and including a first sensing material; a first sensor electrode including a first extending portion in contact with the first sensing material; and a second extending portion in contact with the first sensing material. The first and second extending portions are disposed on the floor of the recess and correspond to each other with a length of at least 30% of the floor width of the recess and the first sensing material connects the first and second extending portions by being disposed between the first and second extending portions.

Description

TECHNICAL FIELD [0001] The present invention relates to a gas sensor, a gas sensor manufacturing method, and a gas sensing device.

An embodiment relates to a gas sensor.

An embodiment relates to a method of manufacturing a gas sensor.

The embodiment relates to a gas sensor having a sensor portion and a light emitting element.

An embodiment relates to a gas sensor having a sensor part and a light emitting element for gas sensing.

An embodiment relates to a semiconductor device for gas detection and a sensing device therefor.

There are many kinds of gases in our living environment. Problems such as gas accidents in general homes, businesses, construction sites, explosion accidents in petroleum combinets, mines, chemical plants, and pollution pollution are continuing. Human sensory organs can not quantitatively determine the concentration of the hazardous gas or can hardly distinguish the type of the gas. In order to cope with this problem, a gas sensor using physical properties or chemical properties of a material has been developed and used for leakage detection, concentration measurement and alarm for gas.

Such gas sensors have been studied for a long time, and many types of gas sensors are now commercially available. When a gas component is adsorbed on the surface of a semiconductor or reacted with an adsorbing gas such as oxygen or the like which has been previously adsorbed, a gas sensor using a semiconductor causes electron exchange between the adsorbing molecules and the surface of the semiconductor, Surface potential, and the like, which are the principle of detecting such a change.

Semiconductor gas sensors are simpler in structure, easier to process, smaller in size and lower in power consumption than optical gas sensors or electrochemical gas sensors through measurement of conductivity by measurement spectrum or ion mobility .

Embodiments provide a gas sensor for gas detection and a method of manufacturing the same.

The embodiment provides a gas sensor in which a sensing member and a sensor electrode are disposed in a recess of a supporting member and a method of manufacturing the same.

An embodiment provides a gas sensor having a sensor portion that detects a gas in response to light emitted from a light emitting element, and a method of manufacturing the same.

Embodiments provide a gas sensor having a light emitting element that emits light on different regions of a substrate and a sensor portion that senses the gas.

An embodiment provides a gas sensor having a light emitting element on a substrate and one or a plurality of sensor portions disposed in a region corresponding to at least one side of the side faces of the light emitting element.

An embodiment provides a gas sensor for a gas sensor.

An embodiment provides a sensing device having a gas sensor for a gas sensor.

A gas sensor according to an embodiment includes: a support member having a first recess; A light emitting element on a first region of the support member; And a first sensor section disposed on a second region of the support member, wherein the light emitting element includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and a second conductivity type semiconductor layer, And a light emitting structure having an active layer between the layers, wherein the first sensor portion is disposed in the first recess, and the first sensing material; A first sensor electrode including a first extension contacting the first sensing material; And a second sensor electrode including a second extension contacting the first sensing material, wherein the first extension and the second extension are disposed at the bottom of the recess, and wherein the bottom width of the recess And the first sensing material is disposed between the first and second extending portions to connect the first and second extending portions.

A sensing device according to an embodiment includes: a package body having a cavity; A gas sensor disposed in the cavity; And a reflective plate having an opening disposed on the gas sensor, the gas sensor comprising: a support member having a first recess; A light emitting element on a first region of the support member; And a first sensor section disposed on a second region of the support member, wherein the light emitting element includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and a second conductivity type semiconductor layer, A first sensing material disposed in the first recess and having a resistance changed by light emitted from the light emitting device; and a second sensing material disposed between the first sensing material and the first sensing material. A first sensor electrode including a first extension contacting the first sensing material; And a second sensor electrode including a second extension contacting the first sensing material, wherein the first extension and the second extension are spaced apart from each other at a surface of the first recess.

According to the embodiment, a plurality of the first and second extending portions may be disposed on the bottom of the recess.

According to an embodiment of the present invention, a second sensor portion is disposed on a third region of the support member, and the second sensor portion is disposed on at least one side of the side surfaces of the light emitting element, and the support member is spaced apart from the first recess And the second sensor portion may include a second sensing material in the second recess and a third and fourth sensor electrodes in contact with the second sensing material.

According to the embodiment, the light emitting device may be disposed between the first and second sensor units.

The first lead electrode and the second lead electrode may include a first lead electrode and a second lead electrode electrically connected to the light emitting element on the support member, And can be electrically separated.

According to an embodiment of the present invention, an insulating layer may be formed on the supporting member, and the insulating layer may be disposed between the supporting member, the first and second lead electrodes, and the first and second sensor electrodes.

According to an embodiment, the light emitting device may include an LED having a substrate on an upper surface of the light emitting structure layer.

According to the embodiment, the light emitting element can emit ultraviolet light.

According to an embodiment, the support member may comprise a substrate of insulating or conductive material

According to an embodiment of the present invention, the first sensing material includes a main sensing material and a catalyst, and the main sensing material is SnO ₂ , CuO, TiO ₂ , In ₂ O ₃ , ZnO, V ₂ O ₅ , RuO ₂ , WO _{3 , ZrO 2, MoO 3, NiO} , CoO, Fe 2 O 3, and AB ₂ O ₄ Wherein the catalyst is selected from the group consisting of platinum (Pt), copper (Cu), rhodium (Rd), gold (Au), palladium (Pd), iron (Fe), titanium (Ti), vanadium V, Cr, Ni, Al, Zr, Nb, Mo, Ru, Rh, Ag, And may include at least one or more of hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), and iridium (Ir).

According to the embodiment, the first and second lead electrodes are electrically connected to the light emitting element on the support member, and a plurality of lead patterns are formed on the cavity bottom. The first and second lead electrodes and the first and second The sensor electrode may be electrically connected to the plurality of lead patterns, and may include a second sensor portion on a third region of the support member, and the package body may include a ceramic material.

The embodiment can improve the reliability of the gas sensor by providing the gas sensor with the sensor part activated by the light emitted from the light emitting element.

The embodiment has an effect that it is possible to prevent failure by the sensing material or to apply a uniform amount of sensing material by applying the sensing material to one or a plurality of recesses of the supporting member.

The embodiment realizes a gas sensor using light of an LED without a heater, thereby solving the problems of durability of the heater and time required for a warm-up time by the heater.

In the embodiment, the size of the gas sensor can be reduced by disposing the light emitting element and the sensor portion on different regions of the substrate.

The embodiment can implement a gas sensor having a flip chip structure light emitting device and a sensor part disposed on a side thereof.

The embodiment can realize a gas sensor having a light emitting element having a horizontal chip structure and a sensor portion on a side thereof.

The embodiment can implement a gas sensor in which a light emitting element of a vertical chip structure and a sensor portion are arranged on a side surface thereof.

The embodiment can improve the sensing sensitivity of the gas sensor.

The embodiment can downsize the sensor for gas sensing.

The embodiment can reduce the power consumption of the sensor for gas sensing.

Embodiments can improve the reliability of sensors for sensing gases and sensing devices having the same.

1 is a plan view of a gas sensor according to a first embodiment.
2 is a cross-sectional view of the gas sensor of Fig. 1 on the AA side.
3 is a plan view of the gas sensor according to the second embodiment.
Fig. 4 is an example of a cross-sectional view of the gas sensor of Fig. 3 on the BB side.
5 is a plan view of the gas sensor according to the third embodiment.
6 to 10 are views showing a manufacturing method of the gas sensor of FIG.
11 is a perspective view of a gas sensor according to the fourth embodiment.
12 is a perspective view of the gas sensor according to the fifth embodiment.
13 is a side sectional view showing an example of a sensing device having the gas sensor of Fig.
14 is an example of the light emitting device of Figs. 11 and 12. Fig.
15 is another example of the light emitting device of Figs. 11 and 12. Fig.
16 is a view for explaining the sensing process in the sensing material of the gas sensor according to the embodiment.
17 is a graph showing the resistance change of the gas sensor according to the embodiment.

The embodiments may be modified in other forms or various embodiments may be combined with each other, and the scope of the present invention is not limited to each embodiment described below. Although not described in the context of another embodiment, unless otherwise described or contradicted by the description in another embodiment, the description in relation to another embodiment may be understood. For example, if the features of configuration A are described in a particular embodiment, and the features of configuration B are described in another embodiment, even if the embodiment in which configuration A and configuration B are combined is not explicitly described, It is to be understood that they fall within the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. In the description of the embodiment according to the present invention, in the case of being described as being formed "on or under" of each element, the upper (upper) or lower (lower) or under are all such that two elements are in direct contact with each other or one or more other elements are indirectly formed between the two elements. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

<Examples>

1 is a plan view of a gas sensor according to a first embodiment, and Fig. 2 is a cross-sectional view taken along the A-A side of the gas sensor of Fig.

1 and 2, a gas sensor according to an embodiment includes a support member 350, sensor electrodes 151 and 153 on the support member 350, and a sensing material 150 connected to the sensor electrodes 151 and 153, . The sensor electrodes 151 and 153 and the sensing material 150 may be defined as a sensor unit, but the present invention is not limited thereto.

The support member 350 has a recess 60 and the sensor electrodes 151 and 153 and the sensing material 150 may be disposed in the recess 60. The gas sensor or sensor unit 105 includes an insulating layer 352 on the support member 350 and the sensor electrodes 151 and 153 and the sensing material 150 are disposed on the insulating layer 352 .

The size of the gas sensor or sensor unit 105 may be in the range of (length) × (length), for example, (300 μm to 20000 μm) × (300 μm to 20000 μm). The thickness or height of the gas sensor 105 may be in the range of, for example, 30 탆 to 500 탆 or 30 탆 to 3000 탆. The first axis direction on the plane may be a transverse direction or an X axis direction, and the second axis direction may be a longitudinal direction or a Y axis direction orthogonal to the X axis direction. The third axis direction may be a height or a thickness direction, or may be a Z axis direction orthogonal to the first and second axis directions.

&Lt; Support member 350 >

The support member 350 may be a conductive or insulating material. The support member 350 may be a semiconductor substrate or a non-semiconductor substrate. The support member 350 may be a substrate of a light transmitting or non-light transmitting material. The support member 350 may be selected from the group consisting of a sapphire substrate (Al ₂ O ₃ ), GaN, SiC, ZnO, Si, GaP, InP, Ga ₂ O ₃ and GaAs. The support member 350 may be formed of a GaN-based semiconductor, for example, a GaN semiconductor. The support member 350 may be an n-type semiconductor layer. The support member 350 may be a bulk GaN single crystal substrate. The support member 350 may be used as a base member for supporting the sensor.

The thickness of the support member 350 may be in the range of 30 占 퐉 or more, for example, 30 占 퐉 to 500 占 퐉 or 30 占 퐉 to 3000 占 퐉. If the thickness is smaller than the thickness of the support member 350, The size of the sensor can be increased. The length of the support member 350 in the direction of the first axis X and the length of the direction of the second axis Y may be the same or different. The gas sensor 105 may be provided with the support member 350 removed or separated.

As another example, the support member 350 may be a circuit board. When the support member 350 is a circuit board having a circuit pattern, the circuit board may be formed of a resin PCB, a metal core PCB (MCPCB), a flexible PCB (FPCB), a ceramic PCB And may include at least one.

The support member 350 may have a recess 60 recessed in a downward direction at the center of the upper surface. The recess 60 may be disposed in a center region spaced apart from the sides of the support member 350. The recess 60 may have a wider upper width B2 than a bottom width B1. The recess 60 may be formed to have a gradually narrower width. The recess 60 may include a bottom surface 61 and a side surface 62 that is inclined relative to the bottom surface 61. The depth H1 of the recess 60 may be 50% or less of the thickness T1 of the support member 350 and the rigidity of the support member 350 may be weakened when the depth exceeds 50%. The shape of the top view of the recess 60 may be circular, polygonal, or elliptical, but is not limited thereto. The recesses (60) may be arranged in the support member (350).

&Lt; Insulating layer 352 >

The insulating layer 352 may be an insulating sheet or a layer, but is not limited thereto. The insulating layer 352 may include, for example, a nitride or oxide-based insulating material, such as SiN _{2 ,} SiN _{4 ,} Si ₃ N ₄ SixNy (x> 0, y> 0), SiO x (X> 0), SiO x N y (x> 0, y> 0) having a SiO ₃ N _y4 containing SiO ₂ comprising at least one of, And Al ₂ O ₃ Al _x O _y (x> 0, y> 0). As another example, the insulating layer 352 may be formed as a single layer or a multilayer. The insulating layer 352 may be formed to be thinner than the thickness of the supporting member 352. The thickness of the insulating layer 352 may be in a range of 200 nm or more, for example, 500 nm to 10,000 nm. If the thickness of the insulating layer 352 is less than the above range, electrical interference may occur. If the thickness of the insulating layer 352 is exceeded, the stress between the insulating layer 352 and the supporting member 350 becomes too large, Reliability may be deteriorated. The insulating layer 352 may be removed when the supporting member 350 is an insulating material.

The sensing material 150 and the sensor electrodes 151 and 153 may be disposed on the insulating layer 352. The insulating layer 352 may extend to the surface of the recess 60 of the support member 350.

&Lt; Sensing material 150 >

The sensing member 150 of the sensor unit according to the embodiment may include a material that is activated by light of a predetermined wavelength. The sensing material 150 may be activated by light emitted from a light emitting device described later. Here, the activation may include a change in resistance of the sensing material 150. The sensing material 150 may be disposed in a direction in which light emitted from the light emitting device proceeds or may be disposed on a path directly irradiated with light or indirectly irradiated.

The sensing member 150 may be in contact with the first and second sensor electrodes 151 and 153 in the recess 60. The sensing material 150 may be disposed in the recess 60 to control the amount and volume of the sensing material 150 to be applied when the sensing material 150 is applied. Accordingly, it is possible to solve the problem that the sensing material 150 is leaked to another region, and the difficulty in adjusting the amount and the volume. The sensing material 150 may be activated by the irradiated light to change the resistance between the first and second sensor electrodes 151 and 153.

The sensing material 150 may be disposed on the surface of the insulating layer 113. The sensing material 150 may be formed of a metal oxide. The sensing material 150 may include a main sensing material and a catalyst. The main sensing material comprises a metal oxide material, and the catalyst may comprise a metal. The main sensing material may be selected from the group consisting of SnO ₂ , CuO, TiO ₂ , In ₂ O ₃ , ZnO, V ₂ O ₅ , RuO ₂ , WO ₃ , ZrO ₂ , MoO _{3 ,} NiO, CoO, Fe ₂ O ₃ , ₂ O ₄ , &Lt; / RTI &gt; and the like. The catalyst of the sensing material 150 may be at least one selected from the group consisting of Pt, Cu, Rh, Au, Pd, Fe, Ti, (Cr), nickel (Ni), aluminum (Al), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium Hf), tantalum (Ta), tungsten (W), rhenium (Re), iridium (Ir) Such a catalyst material may be mixed with the primary sensing material as a doping material in the sensing material 150. [ The sensing material 150 may include materials that may have both sensing and catalytic properties. The material of the sensing material 150 according to the embodiment may be selectively mixed with the main sensing material and the catalyst according to the type of gas to be sensed.

The sensing material 150 may include grains, and the sizes of the grains may be the same or different from each other. The size of the grain may be in the range of 2 nm or more, for example, 2 nm to 20 nm. If the size of the sensing material 150 is smaller than the above range, the sensitivity of the sensing material 150 may be lowered.

The sensing material 150 may mix one or two or more kinds of main sensing materials, and the mixed material may be doped with one or two kinds of catalyst materials. The main sensing material may be in a range of 25 mol% to 75 mol%, mixed with one or two species, and may be set to a range capable of responding to a specific gas and gas sensing characteristics. The catalyst material may be added in an amount of 5 wt% or less, for example, 1 wt% to 5 wt% of the main sensing material. If the catalyst material exceeds the above range, the gas sensing sensitivity may be lowered. The effect may be insignificant. For example, when the SnO ₂ and ZnO are mixed with each other, the sensing material 150 may be mixed with SnO ₂ in a larger proportion than ZnO. For example, the molar ratio of SnO ₂ : ZnO may be 1: 1 to 1: 2.5 Or 1: 1 to 2.5: 1, and the catalyst material may be doped with, for example, platinum (Pt) in the range of 1 wt% to 3 wt% of the main sensing material.

Table 1 below shows the types of target gas and sensing material to be detected.

Target Gas Sensing material Kinds Ethanol ZnO, SnO _2: Pt Alcohol system
Methanol ZnO Propanol ZnO: Fe ₂ O ₃ CO SnO ₂ / TiO ₂ : Nb Carbon oxides series
CO ₂ ZnO NO ZnO Nitrogen oxides system
NO ₂ ZnO, SnO _2: WO ₃ H ₂ ZnO, SnO ₂ : Pd Hydrogen system NH ₃ ZnO, WO ₃ : Ti Ammonia system H ₂ S ZnO, SnO ₂ : Ag VOC system
Acetone ZnO, SnO ₂ : Pd LPG ZnO, SnO _2: Ni SO ₂ SnO ₂ : V

<Sensor electrode>

The electrode structure of the sensor unit according to the embodiment may include a pattern structure that contacts the sensing material 150 and detects a change in resistance from the sensing material 150. The electrode structure may include a first sensor electrode 151 and a second sensor electrode 153. The first sensor electrode 151 includes a first pad portion 10 and a first extension portion 13 extending from the first pad portion 10 to the bottom of the recess 60, 2 sensor electrode 153 includes a second pad portion 30 and a second extension portion 33 extending from the second pad portion 30 to the bottom of the recess 60.

The first and second pads 10 and 30 are pads for bonding wires and may be formed of a metal material such as gold (Au), platinum (Pt), palladium (Pd), aluminum (Al), molybdenum At least one of Au, Mo, Ag, Ti, TiN, W, Ru, Ir, and Cu, Or may be formed as a single layer or multiple layers. The top view shape of the first pad portion 10 may include at least one of a circular shape, an elliptical shape, a polygonal shape, and a hemispherical shape. The second pad portion 30 may have the same shape as the first pad portion 10 or may have another shape and may include at least one of a shape, an ellipse shape, a polygonal shape, and a hemispherical shape.

The first and second pad portions 10 and 30 may be spaced apart from the recess 60. The first and second pad portions 10 and 30 may be spaced apart from the sensing material 150. The sensing material 150 may be disposed between the first and second pad portions 10 and 30. The first and second pad portions 10 and 30 may be disposed on both sides of the sensing material 150 or on either side of the sensing material 150. The first and second pad portions 10 and 30 may be disposed on opposite sides of the sensing material 150. The thickness of the first and second pad portions 10 and 30 may be thicker than the thickness of the first and second extension portions 13 and 33 and may alleviate an external impact when the wire is bonded. The first and second pad portions 10 and 30 may be electrically connected to each other.

The first and second extension portions 13 and 33 are lead wires connected to the plurality of pad portions 10 and 30 and may be formed of gold (Au), platinum (Pt), tungsten (W), zinc (Zn) (Co), palladium (Pd), aluminum (Al), molybdenum (Mo), silver (Ag), titanium (Ti), tin (Sn), zirconium (Zr), magnesium (Mg) (Ti), tungsten (W), Ni-Cr alloy, rubidium (Rb), thorium (Th), platinum rhodium (Rh), copper (Cu), strontium Ti, Cr, Ru, Ir, Ni, Cr, Hg, Ni-Al and Cu, , Or an alloy or a different material. Since the first and second extension portions 13 and 33 are exposed to the outside, they may include an oxidation preventing layer. The extensions 13 and 33 may include a material having a high resistivity, for example, a resistivity of 20 or more. The nichrome may have a resistivity of 108.3.

The first and second extension portions 13 and 33 may be separately disposed between the plurality of pad portions 10 and 30. Each of the first extension portion 13 and the second extension portion 13, 33 may be disposed, for example, with a lead wire continuously connected to each other. Each of the conductive lines may include a linear shape, a curved shape, a bent shape, and a line shape extending in different directions.

The line width of the first and second extension portions 13 and 33 may be at least 2 탆 or more, for example, 2 탆 to 5 탆. If the line width is smaller than the above range, The improvement in sensitivity to changes in resistance may be insignificant. The first and second extensions 10 and 30 may have a thickness of 5 nm or more, for example, 5 nm to 1000 nm.

The first and second extensions 13 and 33 may extend from the upper surface of the support member 350 to a side surface and a bottom surface of the recess 60. The first and second extensions (13, 33) may be spaced apart from each other at the bottom of the recess (60). The first extension portion 13 and the second extension portion 33 have first and second regions R1 and R2 which are parallel to each other and a gap between the first and second regions R1 and R2 (D1) may be in the range of 5 占 퐉 or more, for example, 5 占 퐉 to 200 占 퐉. If it is smaller than the above range, the sensing sensitivity is lowered. If it is larger than the above range, the reaction rate may decrease or disappear. The first and second regions R1 and R2 have a long length in the Y-axis direction and are parallel to each other with respect to the X-axis direction. The lengths of the first and second regions R1 and R2 parallel to each other in the Y-axis direction, that is, the lengths C1 overlapping each other may be equal to or greater than the interval D1. The length C1 may be 30% or more of the bottom width B1 of the recess 60 as shown in FIG. 2, for example, 50% or more. A third region R3 of the sensing material 150 is disposed between the first and second regions R1 and R2. The third region R3 of the sensing material 150 may connect the first and second regions R1 and R2 facing each other with a predetermined length (e.g., C1). Accordingly, when there is a change in resistance in the sensing material 150, the third region R3 may connect the first and second regions R1 and R2.

The first region R1 is a region of the first extending portion 13 which overlaps or contacts the sensing member 150 with a predetermined length and the second region R2 is a region where the second extending portion 33 The sensing member 150 may be a region overlapping or contacting with the sensing member 150 with a predetermined length. At this time, the first and second regions R1 and R2 may be parallel to each other and may be overlapped with a length C1 of 30% or more of the bottom width of the recess 60. If the length C1 is smaller than the above range, the change in sensing resistance may be insignificant and the sensing sensitivity may be lowered. The first and second regions R1 and R2 may not be parallel to each other, but are not limited thereto. The third region R3 of the sensing material 150 may be an area that does not overlap the first and second regions R1 and R2 and connects the first and second regions R1 and R2. The third region R3 may be connected to the first and second regions R1 and R2 with a predetermined resistance when the gas is detected.

The distance D1 between the first and second extensions 13 and 33 may be in the range of 5 mu m or more, for example, 5 mu m to 200 mu m. The resistance value for gas measurement can be determined according to the interval D1 between the first and second extension portions 13 and 33. The closer the interval D1 between the first and second extension portions 13 and 33 is, The resistance value of the sensing material 150 may be lowered. Accordingly, the first and second extension portions 13 and 33 can connect the first and second regions R1 and R2, which correspond to each other, with resistance change of the sensing material 150. [ Since the sensing material 150 has low resistance or conductivity due to light, it can electrically connect the first and second adjacent regions R1 and R2. The sensing material 150 may have a first resistance due to incident light and may be changed to a second resistance lower than the first resistance when an external gas is introduced. Accordingly, the sensing material 150 reduces the electrical resistance between the first and second regions R1 and R2 of the first and second extension portions 13 and 33 by light and gas, The first and second regions R1 and R2 of the first and second extension portions 13 and 33 can be electrically connected through the region R3 of the first and second extension portions 150 and 150, respectively. The resistance between the first and second extension portions 13 and 33 is lowered so that the resistance can be detected by the first and second pad portions 10 and 30. The change in the detected resistance can be measured by the presence or absence of gas by the gas sensor.

As another example, the first and second extensions 13 and 33 may be formed of nano powder, a nano wire, a nano rod, a carbon nanotube (CNT) And graphene, but the present invention is not limited thereto.

The embodiment provides the first and second extension portions 13 and 33 which are in contact with the sensing material 150 of the recess 60 between the first and second pad portions 13 and 33, The initial resistance to the portions 10 and 30 may be changed. A sensing material 150 responsive to light having an arbitrary wavelength is disposed on the first and second extension portions 13 and 33 to change the resistance applied to the first and second extension portions 13 and 33 It is possible to detect whether gas is detected or not. For example, when a resistance lower than the initial resistance applied to the first and second pad portions 10 and 30 is detected, the sensing can be performed in a gas sensing state. Accordingly, the gas sensor 105 according to the embodiment can provide the presence or absence of gas leakage by light having an arbitrary wavelength. Embodiments can reduce the size and thickness of the gas sensor 105. That is, by implementing a sensor using light of an LED without a heater, it is possible to solve the problems of durability of the heater, increase in size due to the heater, and time required for the warm-up time.

The operation of the gas sensor or the sensor unit according to the embodiment will now be described. The sensing material 150 may contact the surfaces of the first and second sensor electrodes 151 and 153 to change the impedance. The sensing material 150 may mix one or two or more kinds of main sensing materials, and the mixed material may be doped with one or two kinds of catalyst materials. The catalyst material may be added in an amount of 5 wt% or less, for example, 1 wt% to 5 wt% of the main sensing material, and the gas sensing sensitivity may be lowered when the catalyst material exceeds the above range. For example, when the SnO ₂ and ZnO are mixed with each other, the sensing material 150 may be mixed with SnO ₂ in a larger proportion than ZnO. For example, the molar ratio of SnO ₂ : ZnO may be 1: 1 to 1: 2.5 Or 1: 1 to 2.5: 1, and the catalyst material can be doped with, for example, platinum (Pt) in the range of 1 wt% to 3 wt% of the main sensing material. Here, since the band gap of SnO ₂ is about 3.6 eV, a photo current can be formed when the light emitted from the light emitting device 101 is 340 nm. The particle size of the main sensing material is in the range of 30 nm or more, for example, 30 nm to 60 nm. If the particle size is small, the characteristics can be improved, but there is a problem of cost increase. When the particle size is larger than the above range, Problems that can not be made in the public (oxygen vacancy) can arise.

Light may be incident on the surface of the sensing material 150. The light may be light emitted from the light emitting element. The light emitting device includes an LED, and the LED may include at least one of ultraviolet light, visible light, and infrared light. The LED may comprise ultraviolet light. The sensing material 150 generates electrons on the surface of the sensing material 150 when the ultraviolet light is irradiated. The ultraviolet wavelength may have a wavelength of 390 nm or less, for example, 200 nm to 390 nm. The wavelength of the ultraviolet light may be different depending on the band gap of the main sensing material. For example, in the case of SnO ₂ , the band gap may be about 3.6 eV. As shown in FIG. 17, when ultraviolet (UV) light is irradiated to the sensing material 150, it can be seen that a current flows in the case of 254 nm or 365 nm. The embodiment can improve the reliability of the gas sensor 105 by providing the gas sensor 105 that generates electrons using the light of the LED. The embodiment realizes the gas sensor 105 using the light of the LED without the heater, thereby solving the problems such as the durability of the heater and the warm-up time due to the heater.

16, when the light L1 is emitted from the light emitting device 101 (step 1), electrons e ^- are generated by the sensing material 150 (Step 2). At this time, the sensing material 150 may first react with nitrogen or oxygen which occupies the largest composition ratio in the atmosphere (Step 3). The nitrogen does not react with the sensing material 150 of the gas sensor as an inert gas and oxygen is adsorbed on the surface of the sensing material 150 and exists in the form of oxide ions such as O ^2- , O ₂ ^- and O ^- At this time, the oxide ions and the gas (G2) may react with each other to move the electrons. At this time, a very large change in impedance, that is, a high sensitivity characteristic, may occur depending on the electron movement on the surface of the sensing material 150. That is, the sensing material 150 generates oxidized ions by the reaction of the electrons generated in response to the light L1 and oxygen, and the generated oxidized ions react with the gas G2 to form the sensing material 150, So that the electrons can be moved. The electron movement in the sensing member 150 is controlled by the resistance R of the third region R3 of the sensing material 150 connected to the first and second regions R1 and R2 of the first and second sensor electrodes 151 and 153 For example, the resistance can be lowered. The change in resistance of the sensing material 150 can be detected by the sensor electrodes 151 and 153. The sensing material 150 may have conductivity by the light L1 and the conductive property may be further improved when the gas G2 is sensed. For example, the resistance of the sensing material 150 may be lowered The first and second sensor electrodes 151 and 153 may be electrically connected to each other by the sensing material 150. As shown in FIG. 17, the sensing resistance level of the gas sensor may be changed to low / high according to the on / off state of the ultraviolet ray (UV). The gas may comprise a _{H 2, CO 2, CO,} HCl, Cl 2, H 2 S, H 2, HCN, NH 3, C 3 H 8, C 4 H 10, CH 4. The sensing material 150 may be a semiconductor ceramic material and may have resistance values ranging from several hundreds of kW to several tens of MW through process and heat treatment.

Fig. 3 is a plan view showing the gas sensor according to the second embodiment, and Fig. 4 is a sectional view taken along the line B-B of the gas sensor of Fig. In the description of Figs. 3 and 4, the same parts as those described above will be referred to above, and some configurations may be dedicated.

3 and 4, the gas sensor includes a support member 350 having a plurality of recesses 60 and 60A, a plurality of sensor electrodes 151, 152 and 153 on the support member 350, And a plurality of sensing members (150, 150A) arranged on the sensing electrodes (60, 60A) and selectively connected to the sensor electrodes (151, 152, 153).

The plurality of recesses 60 and 60A may be spaced apart from each other in at least one of an X-axis direction and a Y-axis direction. Each of these recesses 60 and 60A may have a shape having an upper area larger than the lower area. The volumes of the recesses 60 and 60A may be equal to each other so that the amounts of the sensing materials 150 and 150A distributed in the recesses 60 and 60A can be controlled in the same manner.

The sensing materials 150 and 150A may be the same material or different materials. This can be the same material or different materials depending on the type of gas to be detected. The sensing material 150, 150A may be selected from the materials disclosed in the first embodiment.

The sensor electrode includes first to third sensor electrodes 151, 152 and 153 and the first sensor electrode 151 may be in contact with and connected to the second sensor electrode 152 and the first sensing material 150.

The second sensor electrode 153 may be a common electrode commonly connected to the first and third sensor electrodes 151 and 152. The first and second extension portions 13 and 33 extend to the bottom of the first recess 60 and are connected to the first and second extension portions 13 and 33, 2 region may contact the first sensing material 150 of the first recess 60.

The second sensor electrode 153 has a fourth extension 34 and the fourth extension 34 extends to the bottom of the second recess 60A. The third sensor electrode 152 has a third pad portion 20 and a third extension portion 23 and the third extension portion 23 has a third pad portion 20 extending from the third pad portion 20 to the second recess portion 23, Lt; RTI ID = 0.0 &gt; 60A. &Lt; / RTI &gt; The third and fourth extensions 23 and 34 are brought into contact with the second sensing material 150A in the second recess 60A. The third and fourth extension portions 23 and 34 may correspond to each other with a predetermined distance in the Y axis direction at a predetermined distance from the bottom of the second recess 60A.

The distance D1 between the first and second extension portions 13 and 33 of the first and second sensor electrodes 151 and 153 in contact with the first sensing material 150 The distance D2 between the third and fourth extension portions 33 and 24 of the second and third sensor electrodes 153 and 152 may be different. For example, the distance D1 between the first and second extension portions may be greater than the distance D2 between the third and fourth extension portions 23 and 34. [ The intervals D1 and D2 may vary depending on the resistance change characteristics of the first and second sensing materials 150 and 150A and the gas type. A plurality of regions of the third and fourth extension portions 23 and 34 may be overlapped with the second sensing material 150A. The second sensing material 150A includes a plurality of regions disposed between the plurality of regions of the third and fourth extending portions 23 and 34 and not overlapping with the third and fourth extending portions 23 and 34 can do.

The length C1 in which the first and second extensions 13 and 33 overlap with the opposite sides of the third region R3 of the first sensing material 150 is determined by the length C1 of the first sensing member 150 in the Y- 30% or more, for example, 50% or more of the bottom width of the substrate. The length C2 of the third and fourth extensions 23 and 34 disposed in the second recess 60A and overlapping the second sensing material 150A in the Y axis direction is equal to the length C1 Or may be different. The first and second sensing materials 150 and 150A are activated when a gas to be sensed is inputted by the light, and the resistance is lowered. The first sensing material 150 having the lowered resistance, And the second sensing material 150A may connect the second and third sensor electrodes 153 and 152 to each other. The first to third sensor electrodes 151, 152, and 153 may detect whether different gases are detected.

5 is an example of a gas sensor according to the third embodiment. In the description of FIG. 5, the same portions as those of the above-described configuration can be selectively applied to some configurations with reference to the above description.

5, the gas sensor includes three or more recesses 60, 60A, 60B, and 60C on a support member 350, and each of the recesses 60, 60A, 60B, 150A, 150B, and 150C and the sensor electrodes 151, 152, 153, and 154 are connected. If the three recesses 60, 60A, 60B, and 60C are arranged, they may be arranged in a triangular structure or arranged in a single row, four or more recesses may be arranged in a tetragonal structure, .

The plurality of sensing materials 150, 150A, 150B, and 150C may include materials capable of sensing different gases.

The sensor electrodes 151, 152, 153 and 154 may include pad portions 10, 20, 40 and 50 and extension portions 13, 23, 33, 34, 35, 36, 43 and 53, respectively. In the embodiment, when three or more sensor electrodes are provided, one common electrode, for example, the second sensor electrode 153 may be provided with different extensions 33, 34, 35, And 60C, and is used as a common electrode, so that different gases can be detected through connection with different sensor electrodes.

FIGS. 6 to 11 are views for explaining a method of manufacturing the gas sensor. FIG.

6 and 7, a support member 350, for example, a silicon substrate is prepared and etched. The etch may be wet etched and / or dry etched to form recesses 60 and 60A. The depth and volume of the recesses 60 and 60A can be made the same, and the structure of the recesses 60 and 60A can prevent the overflowing of the material to be applied and inject the same amount.

Referring to FIG. 8, an insulating layer 352 is formed on the surface of the support member 350, and the insulating layer 352 may be deposited by CVD. However, the present invention is not limited thereto. The insulating layer 352 may be formed on the upper surface of the support member 350 and on the surface of the recesses 60 and 60A.

Referring to FIGS. 9 and 3, sensor electrodes 151 and 153 are formed on the support member 350. The sensor electrodes 151 and 153 may have a single layer or multiple layers of the extension portions 10, 20 and 30 and the pad portions 13, 23, 33 and 34. The pad portions 10,20 and 30 of the sensor electrodes 151 and 153 are disposed on the support member 350 and the extension portions 13 and 23 extend from the pad portion to the bottom of the recess Can be extended. The two sensor electrodes may be arranged to correspond to each other in the one recess 60 and 60A.

The sensor electrode may be formed of a metal such as gold (Au), platinum (Pt), tungsten (W), zinc (Zn), cobalt (Co), palladium (Pd), aluminum (Al), molybdenum (Mo) (Ti), tin (Sn), zirconium (Zr), magnesium (Mg), iron (Fe), titanium nitride (TiN), tungsten (W), nickel- (Th), platinum rhodium (Pt-Rh), copper (Cu), strontium (Sr), thallium (Tl), chromium (Cr), ruthenium (Ru), iridium (Ir) May be formed as a single layer or a multilayer using at least one of an alloy (Ni-Cr), mercury (Hg), Ar-Mel alloy (Ni-Al) and copper (Cu), an alloy or a different material.

Referring to FIG. 10, the sensing members 150 and 150A are applied to the recesses 60 and 60A. The sensing members 150 and 150A may apply the same or different materials to the different recesses 60 and 60A, but the present invention is not limited thereto. The sensing material 150 and 150A may be disposed in the recesses 60 and 60A in a screen printing manner. The upper surface of the sensing material 150 or 150A may be a concave, convex or flat surface. The upper surface of the sensing material 150 or 150A may be formed as a concave or convex surface for light incidence.

11 is a perspective view showing an example of the gas sensor according to the fourth embodiment. In the gas sensor of FIG. 11, the sensor electrode and the sensing material described above are defined as a sensor unit.

11, the gas sensor 100A according to the embodiment includes a support member 350, a light emitting device 101 on a first region of the support member 350, and a second region of the support member 350. [ And includes a sensor unit 105 on the top.

The gas sensor 100A may include lead electrodes 320 and 330 connected to the light emitting device 101 on the support member 350 and sensor electrodes 151 and 153 of the sensor unit 105. The gas sensor 100A may include an electrode structure.

The light emitting device 101 and the sensor unit 105 may be disposed on the different regions of the support member 350 in the gas sensor 100A. In the gas sensor 100, the light emitting device 101 and the sensor unit 105 may not overlap in the vertical direction Z. The light emitting device 101 and the sensor unit 105 may be arranged to overlap in the horizontal direction with reference to the light emitting device 101. The resistance of the sensor unit 105 may be changed by the light emitted from the light emitting device 101. The sensor unit 105 may have a low resistance or a conductivity by the light emitted from the light emitting device 101.

The light emitting device 101 according to the embodiment may be implemented by at least one of a horizontal chip structure, a vertical chip structure, and a flip chip structure, but is not limited thereto. The light emitting device 101 includes a light emitting diode (LED), and the LED may emit at least one of ultraviolet light, visible light, and infrared light. The light emitting device 101 according to the embodiment may emit light having a wavelength of ultraviolet light. The distance between the light emitting device 101 and the sensor unit 105 in the gas sensor according to the embodiment may be 5 times or less, for example, 1 to 5 times the length of one side of the light emitting device 101. The size of the gas sensor may be in the range of, for example, 500 占 퐉 to 5000 占 퐉 占 500 占 퐉 to 5000 占 퐉. The thickness or the height of the gas sensor may have a range of 100 占 퐉 or more, for example, 100 占 퐉 to 500 占 퐉. The first axis direction on the plane may be a transverse direction or an X axis direction, and the second axis direction may be a longitudinal direction or a Y axis direction orthogonal to the X axis direction. The third axis direction may be a height or a thickness direction, or may be a Z axis direction orthogonal to the first and second axis directions.

The support member 350 may be a conductive or insulating material. The support member 350 may be a semiconductor material. The support member 350 may be a light-transmitting or non-light-transmitting material. The support member 350 may be selected from the group consisting of a sapphire substrate (Al ₂ O ₃ ), GaN, SiC, ZnO, Si, GaP, InP, Ga ₂ O ₃ and GaAs. The support member 350 may be formed of a GaN-based semiconductor, for example, a GaN semiconductor. The support member 350 may be a bulk GaN single crystal substrate. The support member 350 may be used as a support member for supporting the light emitting device 101 or the gas sensor. When the supporting member 350 is made of a conductive material such as silicon, an insulating layer 352 may be disposed on the supporting member 350.

The thickness of the support member 350 may be in the range of 30 占 퐉 or more, for example, 30 占 퐉 to 300 占 퐉. If the thickness of the support member 350 is less than the thickness of the range, handling during manufacture may be difficult. have. The length of the support member 350 in the direction of the first axis X and the length of the direction of the second axis Y may be the same or different. The length of the support member 350 in the first axis direction and the length in the second axis direction may be a transverse length and a longitudinal length of the gas sensor.

The insulating layer 352 may be disposed on the support member 350. The insulating layer 352 may be disposed on the entire upper surface of the support member 350. The insulating layer 352 is disposed on the upper surface of the supporting member 350 and includes a region between the supporting member 350 and the light emitting device 101 and a region between the supporting member 350 and the sensor unit 105. [ As shown in FIG. The insulating layer 352 may be disposed between the support member 350 and the lead electrodes 320 and 330 connected to the light emitting device 101 and the sensor electrodes 151 and 153 of the sensor unit 105.

The insulating layer 352 may be formed as a single layer or multiple layers using a dielectric material. The insulating layer 352 includes an insulating material or an insulating resin formed of at least one of oxide, nitride, fluoride, and sulfide having at least one of Al, Cr, Si, Ti, Zn, and Zr. The insulating layer 352 may be selectively formed of, for example, SiO ₂ , Si ₃ N ₄ , Al ₂ O ₃ , TiO _2, or MgO. The thickness of the insulating layer 352 may be in the range of 5 탆 or less, for example, 0.1 탆 to 2 탆. If the thickness is smaller than this range, electrical interference may occur. If the thickness is larger than the above range, The thickness can be increased.

At least one of the lead electrodes 320 and 330 may be disposed under the light emitting element 101 and includes first and second lead electrodes 320 and 330, for example. The first and second lead electrodes 320 and 330 may be electrically connected to the light emitting device 101. The first and second lead electrodes 320 and 330 may be arranged in a horizontal layer structure. At least one or both of the first and second lead electrodes 320 and 330 may overlap with the light emitting device 101 in the vertical direction.

The first and second lead electrodes 320 and 330 may extend outside the region of the light emitting device 101. The extending direction of the first and second lead electrodes 320 and 330 may extend in opposite directions with respect to the light emitting device 101. The first and second lead electrodes 320 and 330 may be formed as a via electrode passing through the support member 350 or may further have the via electrode. In this case, A pad connected to the electrode may be disposed.

The first and second lead electrodes 320 and 330 may be formed of one selected from the group consisting of Ti, Cu, Ni, Au, Cr, Ta, Pt, ), Silver (Ag), aluminum (Al), phosphorus (P), or a selective alloy thereof, and may be formed as a single layer or a multilayer. As shown in FIGS. 2 and 5, when the first and second lead electrodes 320 and 330 are multilayered, a bonding layer and a reflective layer may be disposed on the insulating layer 352 or the supporting member 350. Each of the bonding layer / reflective layer may be a single layer or a multilayer. The first and second lead electrodes 320 and 330 may reflect light incident on the periphery of the light emitting device 101.

The first and second lead electrodes 320 and 330 may include pads 323 and 333. The pads 323 and 333 may be removed when the bonding layer is exposed and exposed. The pads 323 and 333 of the first and second lead electrodes 320 and 330 may be spaced apart from each other and may be spaced apart from the first axis direction of the light emitting device 101. The pads 323 and 333 include a first pad 323 disposed on the first lead electrode 320 and a second pad 333 disposed on the second lead electrode 330. The first and second pads 323 and 333 may be disposed on opposite sides of the light emitting device 101.

The first and second pads 323 and 333 may be connected to a connection member such as a wire to receive power. The first and second pads 323 and 333 may not be separately formed when the first and second lead electrodes 320 and 330 have a via structure. The shape of the top view of the first pad 323 and the shape of the top view of the second pad 333 may be different from each other, for example, circular or polygonal. The first and second lead electrodes 320 and 330 are arranged to have a long length in the first axis direction and the light emitting device 101 is connected to the first and second lead electrodes 320 and 330 As shown in FIG.

<Light Emitting Element 101>

The light emitting device 101 includes a light emitting structure layer 120 having a first conductivity type semiconductor layer 121, an active layer 123 and a second conductivity type semiconductor layer 125 as shown in FIG. The light emitting device 101 may include a first electrode 141 connected to the first conductive semiconductor layer 121 and a second electrode 143 connected to the second conductive semiconductor layer 125 have. The light emitting device 101 may include a substrate 111. The light emitting structure layer 120 may be disposed on the substrate 111. At least one of the side surfaces of the light emitting device 101 may correspond to the sensor unit 105.

The light emitting device 101 may be disposed on at least one of the first and second lead electrodes 320 and 330. The light emitting device 101 may be disposed on the gap region 325 between the first and second lead electrodes 320 and 330 and the first and second lead electrodes 320 and 330. However, the present invention is not limited thereto.

Referring to FIG. 14, the light emitting device 101 may include a substrate 111. The substrate 111 may be disposed on the light emitting structure layer 120. The substrate 111 may be a conductive or insulating material. The substrate 111 may be a semiconductor material. The substrate 111 may be a light-transmitting or non-light-transmitting material. The substrate 111 may be selected from the group consisting of a sapphire substrate (Al ₂ O ₃ ), GaN, SiC, ZnO, Si, GaP, InP, Ga ₂ O ₃ and GaAs. The substrate 111 may be formed of a GaN-based semiconductor, for example, a GaN semiconductor. The substrate 111 may be a bulk GaN single crystal substrate.

At least one of the upper surface and the lower surface of the substrate 111 may include a plurality of protrusions 111B and the protrusions 111B may be formed of a material of the substrate 111 or an insulating material. The side surface of the projection may have a hemispherical shape or a polygonal shape. The projections can change the critical angle of the incident light to improve the light extraction efficiency.

The thickness of the substrate 111 may be in the range of 30 탆 or more, for example, 30 탆 to 300 탆. When the thickness of the substrate 111 is smaller than the thickness of the above range, Can be large. The length of the substrate 111 in the first axis X direction and the length in the second axis Y direction may be the same or different. The substrate 111 may be separated from the light emitting device 101 and removed. The light emitting device 101 may be provided without removing the substrate 111 or without a substrate.

A semiconductor layer having at least one of group III-V compound semiconductors and group II-VII compound semiconductors may be formed between the substrate 111 and the light emitting structure layer 120. The semiconductor layer may have a plurality of layers stacked. The growth equipment of the compound semiconductor layer may be an electron beam evaporator, a physical vapor deposition (PVD), a chemical vapor deposition (CVD), a plasma laser deposition (PLD), a dual-type thermal evaporator sputtering, metal organic chemical vapor deposition, or the like, but the present invention is not limited thereto. The substrate on which the semiconductor layer is grown may be a growth substrate or a light-transmitting substrate, and the substrate separately attached to the semiconductor layer may be a conductive or non-conductive substrate or a light-transmitting or non-light-transmitting material.

In the embodiment, a reflective layer may be further disposed on the substrate 111 to reflect light traveling toward the substrate to the sensor unit 105.

The light-

The light emitting structure layer 120 may include a compound semiconductor of group II to VI elements, for example, group II and group V compound semiconductors, or group III and group V compound semiconductors. The light emitting structure layer 120 may be disposed below the substrate 111. The upper surface of the light emitting structure layer 120 may be faced or faced to the substrate 111. Other semiconductor layers may be further disposed between the light emitting structure layer 120 and the substrate 111, but the present invention is not limited thereto. The light emitting structure layer 120 may include a first conductive semiconductor layer 121, an active layer 123, and a second conductive semiconductor layer 125.

The first conductive semiconductor layer 121 may be disposed between the substrate 111 and the active layer 123. The first conductive semiconductor layer 121 includes a first conductivity type dopant and includes n-type dopants such as Si, Ge, Sn, Se, and Te. The first conductivity type semiconductor layer 121 includes a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + y? The first conductive semiconductor layer 121 may be a compound semiconductor of a group III-V element doped with a first conductive dopant, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. The first conductive semiconductor layer 121 may be formed as a single layer or a multilayer, but the present invention is not limited thereto. The first conductive semiconductor layer 121 may have a superlattice structure in which at least two different layers are alternately arranged. The first conductive semiconductor layer 121 may be an electrode contact layer.

The active layer 123 may be disposed between the first conductive semiconductor layer 121 and the second conductive semiconductor layer 125. The active layer 123 selectively includes a single quantum well, a multiple quantum well (MQW), a quantum wire structure, or a quantum dot structure. The active layer 123 includes a well layer and a barrier layer period. The well layer comprises a composition formula of _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1), and wherein the barrier layer is In _x Al _y It may include a composition formula of _{Ga 1 -x- y N (0≤x≤1,} 0≤y≤1, 0≤x + y≤1). InGaN / InGaN, InGaN / InGaN, InAlGaN / InAlGaN, AlGaN / AlGaN, AlGaAs / GaAs, InGaAs / GaAs, InGaP / GaN, InGaN / InGaN, InGaN / InGaN, , InP / GaAs pairs. The period of the well layer / barrier layer may be formed of two or more cycles of the pairs, and the barrier layer may be formed of a semiconductor material having a band gap wider than the band gap of the well layer. The active layer 123 can selectively emit light within a wavelength range from visible light to ultraviolet light, and can emit light having a peak wavelength of a visible light ray or light having a blue peak wavelength, but the present invention is not limited thereto.

The second conductive semiconductor layer 125 may be disposed between the active layer 123 and the lead electrodes 320 and 330 and may include a semiconductor doped with a dopant of the second conductivity type. The second conductivity type semiconductor layer 125 includes a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + y? 1) . The second conductive semiconductor layer 125 may include at least one of compound semiconductors such as GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP and AlGaInP. The second conductive semiconductor layer 125 may be a p-type semiconductor layer, and the second conductive dopant may include Mg, Zn, Ca, Sr, and Ba as p-type dopants. The second conductive semiconductor layer 125 may be formed as a single layer or a multilayer, but the present invention is not limited thereto. The second conductive semiconductor layer 125 may have a superlattice structure in which at least two different layers are alternately arranged. The second conductive semiconductor layer 125 may be an electrode contact layer.

As another example of the light emitting structure layer 120, the first conductivity type semiconductor layer 121 may be a p-type semiconductor, and the second conductivity type semiconductor layer 125 may be an n-type semiconductor. The light emitting structure layer 120 may include at least one of a p-n junction, an n-p junction, an n-p-n junction, and a p-n-p junction structure according to a junction type. P is a p-type semiconductor layer, n is an n-type semiconductor layer, the np junction or pn junction has an active layer, and the npn junction or the pnp junction may have at least one active layer between np and pn .

The light emitting structure layer 120 may further include other layers above and / or below the layers, but the present invention is not limited thereto. The upper surface area of the light emitting structure layer 120 may be narrower than the lower surface area. The area of the bottom surface of the light emitting structure layer 120 may be equal to or less than the area of the top surface of the substrate 111. Here, the area may be an area formed by the X-axis and Y-axis planes. The side surfaces of the light emitting structure layer 120 may be formed as inclined surfaces with respect to the vertical axial direction Z, and such inclined surfaces may improve light extraction efficiency.

The electrode structure of the light emitting device 101 according to the embodiment may include first and second electrodes 141 and 143, and a conductive layer 114. The first electrode 141 may be electrically connected to the first conductive semiconductor layer 121. The first electrode 141 may be implemented as a pad. The first electrode 141 may be disposed under a portion of the first conductive semiconductor layer 121. The first electrode 141 may be disposed in a region higher than the second electrode 143 and face the side surface of the active layer 123. The first electrode 141 may be formed of one selected from the group consisting of Ti, Cu, Ni, Au, Cr, Ta, Pt, Sn, (Ag), aluminum (Al), phosphorus (P), or a selective alloy thereof, and may be formed as a single layer or a multilayer.

The second electrode 143 may be disposed under the second conductive semiconductor layer 125. The second electrode 143 may be electrically connected to at least one of the conductive layer 114 and the second conductive type semiconductor layer 125. The second electrode 143 may be implemented as a pad. The second electrode 143 may be formed of at least one selected from the group consisting of Ti, Cu, Ni, Au, Cr, Ta, Pt, May be formed of at least one of silver (Ag), aluminum (Al) and phosphorus (P), or a selective alloy thereof, and may be formed as a single layer or a multilayer. The first and second electrodes 141 and 143 may be spaced apart from each other in the horizontal direction on the light emitting structure layer 120.

The conductive layer 114 may be disposed under the light emitting structure layer 120. The conductive layer 114 is formed in a region between the second conductive type semiconductor layer 125 and the second electrode 143 and a region between the first conductive type semiconductor layer 121 and the first electrode 141 At least one or both. The conductive layer 114 may be disposed under the second conductive semiconductor layer 125 and may be electrically connected to the second conductive semiconductor layer 125 and the second electrode 143.

The conductive layer 114 may be a transparent layer or a layer of reflective material. The conductive layer 114 may include at least one of a metal, a non-metal, and a semiconductor. The conductive layer 114 may be formed of a metal or an alloy containing at least one of metals such as Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Cu, Or may be formed as a single layer or multiple layers. The conductive layer 114 may include at least one of a non-metal such as a metal oxide or a metal nitride. The metal oxide or the metal nitride may be at least one selected from the group consisting of ITO (indium tin oxide), ITO nitride, IZO (indium zinc oxide), IZON nitride, IZTO (indium zinc oxide), IAZO at least one of materials such as indium gallium zinc oxide, IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), ZnO, IrOx, RuOx, . The conductive layer 114 may have a concavo-convex structure to improve light reflection efficiency.

The passivation layer 133 may be disposed under the light emitting structure layer 120. The passivation layer 133 may be formed of an insulating material. The protective layer 133 can protect the conductive layer 114 and the second electrode 143 and can prevent external moisture penetration and electrical interference. A portion of the protective layer 133 may extend to contact the side surface of the first electrode 141.

The protective layer 133 may be formed of a distributed Bragg reflector (DBR) structure. The distributed Bragg reflector structure includes a structure in which two dielectric layers having different refractive indices are alternately arranged. For example, , A SiO 2 layer, a Si ₃ N ₄ layer, a TiO ₂ layer, an Al ₂ O ₃ layer, and a MgO layer, respectively.

At least one of the first and second electrodes 141 and 143 is disposed in a plurality of ways to improve the bonding strength and stably support the light emitting device 101. [ The light emitting devices 101 may be arranged in a horizontal chip structure or a vertical chip structure.

&Lt; Sensor unit 105 >

The sensor unit 105 may include at least one of the structures of FIGS. The sensor unit 105 may be electrically separated from the light emitting device 101 and may be a sensor for detecting the presence of gas in response to light emitted from the light emitting device 101. The sensor unit 105 may be disposed on the insulating layer 352. Here, the insulating layer 352 may be a protective layer of the sensor unit 105. The sensor unit 105 includes a plurality of sensor electrodes 151 and 153 and a sensing material 150 connected to the plurality of sensor electrodes 151 and 153. The plurality of sensor electrodes 151 and 153 may be disposed on the insulating layer 352 or the supporting member 350. The plurality of sensor electrodes 151 and 153 may include a first sensor electrode 151 and a second sensor electrode 153 separated from each other. The first and second sensor electrodes 151 and 153 may include at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Cu, Au, Hf, Mo, W, TiN, Metal, or alloy, and may be formed as a single layer or multiple layers. The first and second sensor electrodes 151 and 153 may be electrically separated from the first and second lead electrodes 320 and 330.

The first sensor electrode 151 may include a first pad portion 10 and a first extension portion 13 extending from the first pad portion 10 toward the sensing material 150. The first pad portion 10 is electrically connected to an external terminal, and may be connected by, for example, a wire. The first pad portion 10 may have a thickness greater than the thickness of the first extension portion 13, or may further include a bonding layer, but the present invention is not limited thereto. If the first extension portion 13 has a bonding layer, the first pad portion 10 may be removed. 2, the top view shape of the first pad portion 10 may be circular, elliptical or polygonal. The top surface area of the first pad portion 10 may be equal to or larger than the size of the ball to which the ball of the wire can be bonded and may have a smaller width than the pattern width of the first extending portion 13.

The second sensor electrode 153 may include a second pad portion 30 and a second extension portion 33 extending from the second pad portion 30 toward the sensing material 150. The second pad portion 30 is electrically connected to the external terminal, and may be connected by, for example, a wire. The second pad portion 30 may have a thickness greater than that of the second extension portion 33 or may further include a bonding layer, but the present invention is not limited thereto. The second pad portion 30 may be removed when the second extension portion 33 has a bonding layer. The top view shape of the second pad portion 30 may be circular, elliptical or polygonal. The top surface area of the second pad portion 30 may be equal to or larger than the size of the ball to which the ball of the wire can be bonded and may have a smaller width than the pattern width of the second extending portion 33.

The interval (D1 in FIG. 1) between the first and second sensor electrodes 151 and 153 may be in the range of 5 탆 or more, for example, 5 탆 to 200 탆. If the interval is larger than the above range, If it is smaller than the range, a sensing error may occur due to mutual interference.

The first and second extensions 13 and 33 may have a thickness of 100 nm or more, for example, 200 nm or more, but the present invention is not limited thereto. The first and second pad portions 10 and 30 may be arranged to be thicker than the first and second extended portions 13 and 33.

The first extension portion 13 may extend from the first pad portion 10 to the bottom of the recess 60 and may contact the sensing material 150. The second extension portion 33 may extend from the second pad portion 30 toward the first extension portion 13 and may contact the sensing material 150 at the bottom of the recess 60 . The first and second extension portions 13 and 33 may be spaced apart from each other by a predetermined distance D1. The sensing material 150 may be disposed on the first and second extension portions 13 and 33. A plurality of the first extension portions 13 may extend in the direction of the second extension portion 33 or the second pad portion 30. [

The first and second sensor electrodes 151 and 153 may be formed of nano powder, nano wire, nano rod, carbon nanotube (CNT), and graphene. But are not limited thereto.

The sensing material 150 may be in contact with the first and second sensor electrodes 151 and 153 in the recess 60. The sensing material 150 is electrically connected to the first and second sensor electrodes 151 and 153 adjacent to each other in the recess 60 because the resistance of the sensing material 150 is lowered by the light emitted from the light emitting element 101, . The sensing material 150 may have a first resistance due to light incident from the light emitting device 101 and may be changed to a second resistance lower than the first resistance when an external gas is introduced. Accordingly, the sensing member 150 can reduce the electrical resistance between the first and second sensor electrodes 151 and 153, that is, the first and second extension portions 13 and 33, have. Since the first and second sensor electrodes 151 and 153 are electrically connected to each other by the sensing member 150, resistance can be detected by the first and second sensor electrodes 151 and 153. The change in the detected resistance can be measured by the presence or absence of gas by the gas sensor.

The sensing material 150 may be formed of a metal oxide material. The sensing material 150 may include a main sensing material and a catalyst. The main sensing material comprises a metal oxide material, and the catalyst may comprise a metal. The main sensing material may be selected from the group consisting of SnO ₂ , CuO, TiO ₂ , In ₂ O ₃ , ZnO, V ₂ O ₅ , RuO ₂ , WO ₃ , ZrO ₂ , MoO _{3 ,} NiO, CoO, Fe ₂ O ₃ , ₂ O ₄ , &Lt; / RTI &gt; and the like. The catalyst of the sensing material 150 may be at least one selected from the group consisting of Pt, Cu, Rh, Au, Pd, Fe, Ti, (Cr), nickel (Ni), aluminum (Al), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium Hf), tantalum (Ta), tungsten (W), rhenium (Re), iridium (Ir) Such a catalyst material may be mixed with the primary sensing material as a doping material in the sensing material 150. [ The sensing material 150 may include materials that may have both sensing and catalytic properties. The material of the sensing material 150 according to the embodiment may be selectively mixed with the main sensing material and the catalyst according to the type of gas to be sensed. The detection by the sensor unit 105 may mean not only the presence or absence of the measurement gas, but also the change in the concentration of the measurement gas.

Since the sensor portion 105 and the light emitting element 101 are disposed on different regions of the support member 350 in the gas sensor 100A according to the embodiment, The incident light can be incident on the incident surface 105, and the incident efficiency of light can be increased. Thus, the operational reliability of the sensor unit 105 can be improved.

Since the sensor unit 105 according to the embodiment is disposed adjacent to the light emitting element 101 or in a region adjacent to the active layer 123 of the light emitting element 101, the intensity of the irradiated light can be stably provided. Since the distance between the sensor unit 105 and the light emitting device 101 is 2000 mu m or less, the reliability of the gas sensor can be improved by minimizing the light intensity and the light intensity of the irradiated light.

The embodiment can fix the amount of application of the sensing material 150 and solve the problem that the sensing material 150 overflows and the difficulty of adjusting the amount. Therefore, it is possible to provide a gas sensor having a uniform sensing sensitivity.

The sensing material 150 of the sensor unit 105 according to the embodiment may change resistance between the first and second sensor electrodes 151 and 153 to detect the presence or absence of gas sensing by the first and second sensor electrodes 151 and 153 . For example, when gas is detected in the sensing material 150, the resistance value is lowered and the resistance value can be detected by the first and second sensor electrodes 151 and 153. Or if the sensing material 150 is free of gas, the sensing material 150 may be an insulation resistance. If the change in the resistance value of the sensing material 150 is changed by about 2%, the first and second sensor electrodes 151 and 153 can detect the gas sensing.

The gas sensor according to the embodiment can reduce the price because it uses the light of the light emitting element 101 and can prevent reliability deterioration due to thermal shock without using a heater and can be applied to MEMS (Microelectromechanical systems) Thus reducing the complexity of processes and packaging. Since the gas sensor according to the first embodiment is disposed in the region adjacent to the sensor portion 105 for gas detection and the light emitting element 101, packaging of the gas sensor can be facilitated. The sensor unit 105 according to the embodiment can detect the change in resistance by the sensing member 150 even if the bottom of the sensing member 150 is disposed so as to contact only the region between the first and second extended portions 13 and 33 can do.

When the light emitting device 101 according to the embodiment emits ultraviolet light, the ultraviolet LED chip has a characteristic that the light output of the corner portion is lower than that of the center region. Accordingly, the sensing material 150 may be disposed so as to correspond to the center area of the side surface of the light emitting device 101 rather than the peripheral area thereof. The peripheral region may include an area adjacent to each edge of the light emitting device 101. [

The first and second pad electrodes 10 and 30 of the sensor unit 105 are separated from the light emitting device 101 or separated from the first and second lead electrodes 320 and 330, Can be freely arranged.

Fig. 12 is a modification of the gas sensor of Fig. 11, which is an example having a plurality of sensor units. Any one of the plurality of sensor units 105 and 105A will be described as the sensor unit, and the same parts as those of the sensor unit will be described with reference to the same reference numerals.

12, the gas sensor includes a light emitting element 101 on a first region of a support member 350, a first sensor portion 105 on a second region, and a second sensor portion 105A ). The first sensor unit 105A or the second sensor unit 105A will refer to the sensor unit described above.

The light emitting device 101, the first sensor unit 105, and the second sensor unit 105A may be disposed on different regions of the support member 350. The light emitting device 101 may be disposed between the first sensor unit 105 and the second sensor unit 105A. The light emitting device 101 may be disposed between the first and second sensing members 150 and 150A. The first and second sensor units 105 and 105A may be disposed in areas corresponding to different sides of the light emitting device 101. [ The first and second sensor units 105 and 105A may be disposed in areas corresponding to at least two sides of the light emitting device 101. [ The first and second sensor units 105 and 105A may be disposed in areas corresponding to opposite sides of the light emitting device 101. The first and second sensing materials 150 and 150A may be disposed on opposite sides or different sides of the light emitting device 101. The first and second sensing members 150 and 150A may be disposed in the recesses 60 and 60A of the support member 350.

The distance between the first sensor part 105 and the second sensor part 105A is larger than the distance between the light emitting element 101 and the first sensor part 105 and the distance between the light emitting element 101 and the second sensor part 105A, May be larger than the distance between the sensor portions 105A.

The first sensor unit 105 may include first and second sensor electrodes 151 and 153 and a first sensing material 150. The first sensing material 150 may be disposed within the first recess 60 And may be connected to or contacted with the first and second sensor electrodes 151 and 153. The second sensor portion 105A may include third and fourth sensor electrodes 151A and 153A and a second sensing material 150A and the second sensing material 150A may include a second recess 60A, And may be connected to or contacted with the third and fourth sensor electrodes 151A and 153A. The first to fourth sensor electrodes 151, 153, 151A, and 153A may be selectively used for the same configuration with reference to the description of the sensor electrodes described above. The first and second sensing members 150 and 150A may be the same or different from each other. In this case, when the first and second sensing materials 150 and 150A are different, different gases can be sensed and detected.

The first and second sensing materials 150 and 150A may be formed of a metal oxide. The first and second sensing materials 150 and 150A may include a main sensing material and a catalyst. The main sensing material comprises a metal oxide material, and the catalyst may comprise a metal. The main sensing material may be selected from the group consisting of SnO ₂ , CuO, TiO ₂ , In ₂ O ₃ , ZnO, V ₂ O ₅ , RuO ₂ , WO ₃ , ZrO ₂ , MoO _{3 ,} NiO, CoO, Fe ₂ O ₃ , ₂ O ₄ , &Lt; / RTI &gt; and the like. The catalysts of the first and second sensing materials 150 and 150A may be selected from the group consisting of Pt, Cu, Rh, Au, Pd, Fe, Ti, , Vanadium (V), chromium (Cr), nickel (Ni), aluminum (Al), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru) And may include at least one or more of Ag, hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), and iridium (Ir). Such a catalyst material may be mixed with the primary sensing material as a doping material in the first and second sensing materials 150 and 150A. The first and second sensing materials 150 and 150A may include materials that can have both sensing and catalytic properties. The materials of the first and second sensing materials 150 and 150A may be selectively mixed with the main sensing material and the catalyst depending on the type of gas to be sensed.

The first sensing material 150 may contact the surfaces of the first and second sensor electrodes 151 and 153 to change the impedance. The second sensing material 150A may contact the surfaces of the third and fourth sensor electrodes 151A and 153A to change the impedance. The first and second sensing materials 150 and 150A may mix one or two or more kinds of main sensing materials, and may dope the mixed material with one or two kinds of catalyst materials. The catalyst material may be added in an amount of 5 wt% or less, for example, 1 wt% to 5 wt% of the main sensing material, and the gas sensing sensitivity may be lowered when the catalyst material exceeds the above range. For example, when one of the first and second sensing materials 150 and 150A is mixed with SnO ₂ and ZnO, SnO ₂ may be mixed at a higher ratio than ZnO. For example, the molar ratio of SnO ₂ : ZnO May be mixed in a ratio of 1: 2.5 to 2.5: 1 or 2: 1, and the catalyst material may be doped with, for example, platinum (Pt) in the range of 1 wt% to 3 wt% of the main sensing material. Here, since the band gap of SnO ₂ is about 3.6 eV, a photo current can be formed when the light emitted from the light emitting device 101 is 340 nm. The particle size of the main sensing material is in the range of 30 nm or more, for example, 30 nm to 60 nm. If the particle size is small, the characteristics may be improved, but there is a problem of cost increase. When the particle size is larger than the above range, Problems that can not be made in the public (oxygen vacancy) can arise.

When the light is irradiated from the light emitting element 101, electrons are generated by the first and second sensing materials 150 and 150A, and adsorbed on the surfaces of the sensing materials 150 and 150A, is O ^2-, O ₂ ^- and O ^- is present in the form of oxide ions, this time can give to the oxide ion and reaction gas to move the electrons. At this time, a very large change in impedance, that is, a high sensitivity characteristic, may be caused by the movement of electrons on the surfaces of the sensing materials 150 and 150A. That is, the sensing materials 150 and 150A generate oxidized ions by the reaction of electrons and oxygen generated in response to light, and the generated oxidized ions react with the gases to transmit electrons through the sensing materials 150 and 150A. Can be moved. Electromagnetic movement in the sensing members 150 and 150A can change the resistance between the first and second sensor electrodes 151 and 153 and the resistance between the third and fourth sensor electrodes 151A and 153A have. The change in resistance of the first and second sensing members 150 and 150A in the sensor units 105 and 105A can be detected by the sensor electrodes.

13 is a side cross-sectional view of the sensing device with the gas sensor of Fig. The gas sensor is an example of the gas sensor of Fig.

13, the sensing device includes a package body 360, a gas sensor 100A as described in the embodiment within the cavity 352 of the package body 360, a reflective plate 370 on the gas sensor 100A, . &Lt; / RTI &gt;

The package body 360 may include at least one of a resin-made PCB, a metal core PCB (MCPCB) having a metal core, and a flexible PCB (FPCB), but the present invention is not limited thereto. The package body 360 may include a ceramic material. The external size of the fraud package body 360 may be in the range of at least one side of 6 mm or more, for example, 6 mm to 12 mm × 5 mm to 12 mm.

The package body 360 has a cavity 365 and the gas sensor 100A may be disposed in the cavity 365. [ The depth of the cavity 365 may be at least 1 mm, and may range, for example, from 1 mm to 3 mm. The width and length of the cavity 365 may be at least 4 mm or more, for example, 4 mm to 10 mm.

A plurality of lead patterns may be disposed on the bottom of the cavity 365, and the plurality of lead patterns may be electrically connected to the pad portions of the gas sensor 100A with a connection member such as a wire or via structure. A bottom pattern may be disposed on the bottom of the package body 360 and may be connected to the lead pattern on the bottom of the cavity 365 by a via structure. Power can be supplied through this lower pattern or the sensing resistance can be detected.

The package body 360 may be disposed around the gas sensor 100A to reflect the light emitted from the light emitting device 101 of the gas sensor 100A, The heat can be dissipated. The package body 360 may be disposed on a circuit board or may be coupled to another structure.

A step structure 362 may be disposed on the package body 360. The step structure 362 may be provided with a reflection plate 370. The reflection plate 370 may reflect light to prevent leakage of light. The reflection plate 370 may be closely attached to or adhered to the stepped structure 362 of the package body 360. [ The reflective plate 370 may be in contact with the package body 360 with an adhesive (not shown). The sensor unit 105 can detect gas exposure by a gas, for example, a harmful gas introduced through the opening 372 of the reflection plate 370 and the light emitted from the light emitting device 101. The openings 372 may be arranged in one or a plurality of openings.

Since the light emitting device 101 and the sensor unit 105 are disposed on different regions of the gas sensor 100A, the configuration of another embodiment described above can be selectively applied. One of the first and second sensor electrodes 151 and 153 may be commonly connected to the light emitting device 101. For example, the first sensor electrode 151 and the first electrode may be commonly connected to each other. The present invention is not limited thereto.

As another example, in the embodiment, the light emitting elements 101 are formed as one unit, but a plurality of the light emitting elements 101 may be disposed, and the sensor units 105 may be disposed between the plurality of light emitting elements, . The plurality of light emitting devices may emit the same wavelength or different wavelengths.

Detection of the gas sensed by the sensing device having the gas sensor according to the embodiment is detected by the signal processing circuit and is transmitted through the transmission module via wired and / or wireless, or through the output module to the alarm or display mode To the user.

15 is another example of the light emitting device according to the embodiment.

15, a light emitting device 101 includes a substrate 221 and a light emitting structure layer 225. The substrate 221 is disposed on the light emitting structure layer 225, 210 may be disposed on the first and second electrodes 245, 247. The substrate 221 may be, for example, a translucent, conductive substrate or an insulating substrate. A plurality of protrusions (not shown) may be formed on an upper surface and / or a lower surface of the substrate 221, and each of the plurality of protrusions may include at least one of a side surface, a hemispherical shape, a polygonal shape, And may be arranged in a stripe form or a matrix form. The protrusions can improve the light extraction efficiency. A semiconductor layer such as a buffer layer (not shown) may be disposed between the substrate 221 and the first conductivity type semiconductor layer 222, but the present invention is not limited thereto. The substrate 221 may be removed, but is not limited thereto. The light emitting structure layer 225 includes a first conductive semiconductor layer 222, a second conductive semiconductor layer 224 and an active layer 223 between the first and second conductive semiconductor layers 222 and 224. Other semiconductor layers may be disposed above and / or below the active layer 223, but the present invention is not limited thereto. Such a light emitting structure layer 225 will be described with reference to the description of the embodiments disclosed above.

The first and second electrodes 245 and 247 may be disposed under the light emitting structure layer 225. The first electrode 245 is in contact with and electrically connected to the first conductivity type semiconductor layer 222 and the second electrode 247 is in contact with and electrically connected to the second conductivity type semiconductor layer 224. [ . The first electrode 245 and the second electrode 247 may be made of a metal having properties of an ohmic contact, an adhesive layer, and a bonding layer, and may not be transparent. The first and second electrodes 245 and 247 may have a polygonal or circular bottom shape.

The light emitting device 101 includes first and second electrode layers 241 and 242, a third electrode layer 243, and dielectric layers 231 and 233. Each of the first and second electrode layers 241 and 242 may be formed as a single layer or a multilayer, and may function as a current diffusion layer. The first and second electrode layers 241 and 242 include a first electrode layer 241 disposed under the light emitting structure layer 225; And a second electrode layer 242 disposed under the first electrode layer 241. The first electrode layer 241 diffuses a current, and the second electrode layer 242 reflects incident light. Here, the recess 226 exposes a part of the light emitting structure layer 225 through the first and second electrode layers 241 and 242. A portion of the light emitting structure layer 225 may be a region of the first conductivity type semiconductor layer 222.

The first and second electrode layers 241 and 242 may be formed of different materials. The first electrode layer 241 may be formed of a light-transmitting material, for example, a metal oxide or a metal nitride. The first electrode layer 241 may be formed of, for example, indium tin oxide (ITO), ITO nitride, indium zinc oxide (IZO), indium zinc oxide (IZO) , Indium gallium zinc oxide (IGZO), indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO) and gallium zinc oxide (GZO). The second electrode layer 242 may contact the lower surface of the first electrode layer 241 and function as a reflective electrode layer. The second electrode layer 242 includes a metal such as Ag, Au, or Al. The second electrode layer 242 may partially contact the lower surface of the second conductive type semiconductor layer 224 when a portion of the first electrode layer 241 is removed.

As another example, the structures of the first and second electrode layers 241 and 242 may be stacked in an omni directional reflector layer (ODR) structure. The omnidirectional reflection structure may have a stacked structure of a first electrode layer 241 having a low refractive index and a second electrode layer 242 made of a highly reflective metal material in contact with the first electrode layer 241. The electrode layers 241 and 242 may have a laminated structure of, for example, ITO / Ag. The total reflection angle at the interface between the first electrode layer 241 and the second electrode layer 242 can be improved.

As another example, the second electrode layer 242 may be removed and formed of a reflective layer of another material. The reflective layer may be formed of a distributed Bragg reflector (DBR) structure. The distributed Bragg reflector structure includes a structure in which two dielectric layers having different refractive indices are alternately arranged. For example, a SiO2 layer, Si ₃ N ₄ layer, TiO ₂ layer, Al ₂ O ₃ layer, and MgO layer, respectively. As another example, the electrode layers 241 and 242 may include both a dispersed Bragg reflection structure and an omnidirectional reflection structure. In this case, a light emitting chip having a light reflectance of 98% or more can be provided. Since the light emitted from the second electrode layer 242 is emitted through the substrate 311, the light emitting chip mounted in the flip-type can emit most of the light in the vertical direction.

The third electrode layer 243 is disposed under the second electrode layer 242 and is electrically insulated from the first and second electrode layers 241 and 242. The third electrode layer 243 may be formed of a metal such as titanium, copper, nickel, gold, chromium, tantalum, platinum, tin, ), Silver (Ag), and phosphorus (P). A first electrode 245 and a second electrode 247 are disposed under the third electrode layer 243.

The dielectric layers 231 and 233 prevent unnecessary contact between the first and second electrode layers 241 and 242, the third electrode layer 243, the first and second electrodes 245 and 247, and the light emitting structure layer 225. The dielectric layers 231 and 233 include first and second dielectric layers 231 and 233. The first dielectric layer 231 is disposed between the third electrode layer 243 and the second electrode layer 242. The second dielectric layer 233 is disposed between the third electrode layer 243 and the first and second electrodes 245 and 247.

The third electrode layer 243 is connected to the first conductive semiconductor layer 222. The connection portion 244 of the third electrode layer 243 protrudes from the first and second electrode layers 241 and 242 and the recess 226 of the light emitting structure layer 225 and is electrically connected to the first conductive semiconductor layer 222, . Here, the recess 226 may have a gradually narrower width as it is adjacent to the substrate 221. The recess 226 may provide a sloped surface. A plurality of the recesses 226 may be disposed apart from each other. The connection portion 244 may be disposed in each of the recesses 226. The recesses 226 may extend through the second conductivity type semiconductor layer 125 and the active layer 123 to a portion of the first conductivity type semiconductor layer 121. A portion 232 of the first dielectric layer 231 extends around the connection portion 244 of the third electrode layer 243 to form the third electrode layer 243 and the first and second electrode layers 241 and 242, Thereby blocking the electrical connection between the conductive semiconductor layer 224 and the active layer 223. An insulating layer may be disposed on the side surface of the light emitting structure layer 225 for lateral protection, but the present invention is not limited thereto.

The second electrode 247 is disposed below the second dielectric layer 233 and is electrically connected to at least one of the first and second electrode layers 241 and 242 through open regions of the first dielectric layer 231 and the second dielectric layer 233 One or both. The first electrode 245 is disposed below the second dielectric layer 233 and is connected to the third electrode layer 243 through an open region of the second dielectric layer 233. The protrusion 248 of the second electrode 247 is electrically connected to the second conductive type semiconductor layer 224 through the first and second electrode layers 241 and 242 and the protrusion 246 of the first electrode 245 Is electrically connected to the first conductive type semiconductor layer 222 through the third electrode layer 243.

A plurality of connection portions 246 connected to the first electrode 245 can be disposed to improve current diffusion. The first and second electrodes 245 and 247 may be provided under the light emitting structure layer 225 in a large area. The lower surfaces of the first and second electrodes 245 and 247 can be provided on the same horizontal surface in a larger area, so that the bonding area with the bonding member can be improved. Accordingly, the efficiency of bonding the first and second electrodes 245 and 247 to the joining member can be improved.

The gas sensor or sensing device according to the embodiment can be applied to a place where gases such as various kinds of toxic gas or explosive gas are generated or a space applied or enclosed in a device such as a vehicle or a mobile device such as a vehicle lamp. Or to indoor or outdoor sensing devices.

The features, structures, effects, and the like described in the embodiments are included in at least one embodiment and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Accordingly, the contents of such combinations and modifications should be construed as being included in the scope of the embodiments.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. It can be seen that the modification and application of branches are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

10, 30: pad portion
13, 33:
60, 60A: recess
100, 100A: Gas sensor
101: Light emitting element
105 and 105A:
150, 150A:
151, 153:
320, 330: lead electrode
350: Support member
352: insulating layer
360: Package body

Claims (10)

A support member having a first recess;
A light emitting element on a first region of the support member; And
A first sensor portion is disposed on a second region of the support member,
The light emitting device includes a light emitting structure having a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer,
The first sensor unit is disposed in the first recess, and includes a first sensing material; A first sensor electrode including a first extension contacting the first sensing material; And a second sensor electrode including a second extension contacting the first sensing material,
Wherein the first extension and the second extension are disposed at the bottom of the recess and have a length equal to or greater than 30% of the bottom width of the recess and correspond to each other,
Wherein the first sensing member is disposed between the first and second extending portions to connect the first and second extending portions. The gas sensor according to claim 1, wherein a plurality of said first and second extending portions are disposed on the bottom of said recess. The apparatus of claim 1, further comprising a second sensor portion on a third region of the support member,
Wherein the second sensor portion is disposed on at least one side surface of the light emitting device,
Wherein the support member includes a second recess spaced apart from the first recess,
Wherein the second sensor portion includes a second sensing material at a second recess and third and fourth sensor electrodes contacted with the second sensing material. The gas sensor according to claim 3, wherein the light emitting element is disposed between the first and second sensor units. The liquid crystal display device according to any one of claims 1 to 4, further comprising a first lead electrode and a second lead electrode electrically connected to the light emitting element on the supporting member,
Wherein the first lead electrode and the second lead electrode are electrically separated from the first and second sensor electrodes. 6. The semiconductor device according to claim 5, further comprising an insulating layer on the supporting member,
Wherein the insulating layer is disposed between the supporting member, the first and second lead electrodes, and the first and second sensor electrodes. The gas sensor according to any one of claims 1 to 4, wherein the light emitting element comprises an LED having a substrate on an upper surface of the light emitting structure layer. The gas sensor according to any one of claims 1 to 4, wherein the light emitting element generates ultraviolet light. 5. The gas sensor according to any one of claims 1 to 4, wherein the support member comprises a substrate of an insulating or conductive material. 5. The sensor according to any one of claims 1 to 4, wherein the first sensing material comprises a main sensing material and a catalyst,
The main sensing material is _{SnO 2, CuO, TiO 2,} In 2 O 3, ZnO, V 2 O 5, RuO 2, WO 3, ZrO 2, MoO 3, NiO, CoO, Fe 2 O 3, and AB ₂ O ₄ &lt; / RTI &gt;
The catalyst may be selected from the group consisting of platinum, copper, rhodium, gold, palladium, iron, titanium, vanadium, chromium, nickel, (Al), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), silver (Ag), hafnium (Hf), tantalum , Tungsten (W), rhenium (Re), and iridium (Ir).

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