KR20180075323A - Semiconductor device - Google Patents

Abstract

According to an embodiment of the present invention, a semiconductor device comprises a semiconductor structure, a first electrode, an electrode 2-1, and an electrode 2-2. The semiconductor structure includes a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer which is arranged between the first conductive semiconductor layer and the second conductive semiconductor layer. The first electrode is arranged on the first conductive semiconductor layer. The electrode 2-1 is arranged on the second conductive semiconductor layer. The electrode 2-2 is arranged on the second conductive semiconductor layer and is separated from the electrode 2-1. The second conductive semiconductor layer arranged between the electrode 2-1 and the electrode 2-2 is thinner than the second conductive semiconductor layer which is vertically overlapped with the electrode 2-1 and the electrode 2-2. The electrode 2-2 faces the electrode 2-1, and includes a first area which is closest to the electrode 2-1. The electrode 2-1 faces the electrode 2-2 and includes a second area which is closest to the electrode 2-2. The relationship between the width (W1) of the first area and the width (W2) of the second area satisfies W1 >= W2. The present invention is able to improve optical power of the semiconductor device.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

Embodiments relate to semiconductor devices.

Semiconductor devices including compounds such as GaN and AlGaN have many merits such as wide and easy bandgap energy, and can be used variously as light emitting devices, light receiving devices, and various diodes.

Particularly, a light emitting device such as a light emitting diode or a laser diode using a semiconductor material of Group 3-5 or 2-6 group semiconductors can be applied to various devices such as a red, Blue, and ultraviolet rays. By using fluorescent materials or combining colors, it is possible to realize a white light beam with high efficiency. Also, compared to conventional light sources such as fluorescent lamps and incandescent lamps, low power consumption, , Safety, and environmental friendliness.

In addition, when a light-receiving element such as a photodetector or a solar cell is manufactured using a semiconductor material of Group 3-5 or Group 2-6 compound semiconductor, development of a device material absorbs light of various wavelength regions to generate a photocurrent , It is possible to use light in various wavelength ranges from the gamma ray to the radio wave region. It also has advantages of fast response speed, safety, environmental friendliness and easy control of device materials, so it can be easily used for power control or microwave circuit or communication module.

Accordingly, the semiconductor device can be replaced with a transmission module of an optical communication means, a light emitting diode backlight replacing a cold cathode fluorescent lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, White light emitting diodes (LEDs), automotive headlights, traffic lights, and gas and fire sensors. In addition, semiconductor devices can be applied to high frequency application circuits, other power control devices, and communication modules.

A semiconductor device using optical communication means is typically an electric field absorption modulator (EAM) using a short wavelength of a laser diode. However, the laser diode is not only difficult to manufacture, but also has a difficulty in aligning the optical modulator and the laser diode by a narrow beam. Therefore, there is a problem that the light output is lowered.

The embodiment provides a semiconductor device with improved light output.

The embodiment provides a semiconductor device in which the alignment of the light emitting portion and the light modulation portion is improved.

The problems to be solved in the embodiments are not limited to these, and the objects and effects that can be grasped from the solution means and the embodiments of the problems described below are also included.

A semiconductor device according to an embodiment of the present invention includes a semiconductor structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer ; A first electrode disposed on the first conductive semiconductor layer; A second-1 electrode disposed on the second conductive type semiconductor layer; And a second -2 electrode disposed on the second conductivity type semiconductor layer and spaced apart from the second -1 electrode, and the second electrode between the second electrode and the second electrode, The thickness of the conductive type semiconductor layer is thinner than the thickness of the second conductivity type semiconductor layer vertically overlapped with the second-first electrode and the second-second electrode, and the second- And the second electrode includes a first region closest to the second electrode, and the second electrode includes a second region facing the second electrode and a second region facing the second electrode, , And the width (W1) of the first region may have a relationship of a width (W2) of the second region and W1? W2.

According to the embodiment, the light output of the semiconductor element can be improved.

According to the embodiment, the alignment of the light emitting portion and the light modulation portion of the semiconductor element can be improved.

The various and advantageous advantages and effects of the present invention are not limited to the above description, and can be more easily understood in the course of describing a specific embodiment of the present invention.

1 is a conceptual diagram of an optical communication system according to the present invention.
2 is a conceptual diagram illustrating a process of modulating an optical signal by a semiconductor device according to the present invention.
3 is a perspective view of a semiconductor device according to an embodiment of the present invention.
4 is a cross-sectional view of the region I-I 'of FIG.
5 is an enlarged view of a portion A in Fig.
6A to 6C are plan views according to various modifications of the semiconductor device according to an embodiment of the present invention.
FIG. 7 is an enlarged view of a region corresponding to portion A of FIG. 4 among semiconductor devices according to another embodiment of the present invention. FIG.
8 is a graph showing a current value according to a voltage of a semiconductor device and its comparative example according to an embodiment of the present invention.
9 is a conceptual diagram of an optical transmission module according to the present invention.

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.

In the description of the embodiments, in the case where one element is described as being formed "on or under" another 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.

The semiconductor device may include various electronic devices such as a light emitting device, a light receiving device, and an optical modulator. The light emitting device, the light receiving device, and the optical modulator may include the first conductivity type semiconductor layer, the active layer and the second conductivity type semiconductor layer have.

The semiconductor device according to this embodiment may be a light emitting device and an optical modulator.

The light emitting device emits light by recombination of electrons and holes, and the wavelength of the light is determined by the energy band gap inherent to the material. Thus, the light emitted may vary depending on the composition of the material.

The optical modulator may be an electro-absorption modulator (EAM). However, the present invention is not limited thereto. The electric field absorptive modulator can be driven at a low voltage and the device can be downsized. The degree of optical absorption of the optical modulator may vary depending on the applied voltage. That is, the optical modulator can output the modulated light by off-state by absorbing (absorbing) the incident light to the outside according to the change of the applied voltage.

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

1 is a conceptual diagram of an optical communication system according to the present invention.

1, an optical communication system according to the present invention comprises a first optical transceiver 3 in communication with a first host 1, a second optical transceiver 4 in communication with a second host 2, And a channel connected between the transceiver 3 and the second optical transceiver 4.

The first host 1 and the second host 2 are not particularly limited as long as they are electronic devices capable of communicating with each other. Illustratively, the first host 1 may be a server and the second host 2 may be a personal computer.

The first optical transceiver 3 and the second optical transceiver 4 may be bidirectional communication modules each including an optical transmitting module 5 and a light receiving module 6 but the embodiments of the present invention are not limited thereto Do not. Illustratively, the first optical transceiver 3 may be an optical transmission module and the second optical transceiver 4 may be a light receiving module. Hereinafter, a bidirectional communication method will be described.

The optical transmission module 5 of the first optical transceiver 3 can be connected to the optical receiving module 6 of the second optical transceiver 4 by the first optical fiber 8. The optical transmission module 5 can convert an electrical signal of the host into an optical signal. The control unit 7 can modulate the optical signal according to the electrical signal of the host. Illustratively, the control unit 7 may include a driver IC.

The optical receiving module 6 of the first optical transceiver 3 may be connected to the optical transmitting module 5 of the second optical transceiver 4 by means of the second optical fiber 9. The light receiving module 6 can convert an optical signal into an electric signal. The control unit 7 can amplify (TIA) the converted electrical signal or extract the packet information from the electrical signal and transmit it to the host.

Meanwhile, the optical transmission module 5 may include the semiconductor device 100 according to the present invention.

2 is a conceptual diagram illustrating a process of modulating an optical signal by a semiconductor device according to the present invention.

Referring to FIG. 2, the semiconductor device 100 according to the present invention may include a light emitting portion 5a and a light modulating portion 5b. The semiconductor device 100 may be a component of the optical transmission module 5 of FIG.

The semiconductor device 100 can modulate the optical signal L1 using the electrical signal E1. That is, the light emitted from the light emitting portion 5a can be modulated by the light modulating portion 5b. Here, the case of providing the electric signal E1 may be referred to as " 1 state ", and the case of not providing the electric signal E1 may be referred to as the " 0 state. &Quot; The electric signal E1 may be a reverse bias voltage.

When the semiconductor device 100 is in the " 1 state ", the semiconductor device 100 can emit the optical signal L1 (On-state) Off-state. Accordingly, the semiconductor device 100 can output a pulsed light signal having a period and not emitting or emitting the optical signal L1.

Meanwhile, the semiconductor device 100 according to the present invention has a bend energy band gap structure in the absence of an electric field, and has a relatively flat energy band gap structure when a reverse voltage is provided.

More specifically, the semiconductor device 100 according to the present invention can absorb light in the active layer in the absence of an electric field. That is, the semiconductor device 100 according to the present invention includes a nitride-based semiconductor, and the energy band gap of the active layer is formed asymmetrically. This is because there is a strong piezoelectric field inside the light absorption layer. Such a piezoelectric field can be caused by various causes. By way of example, the piezoelectric field can be caused by strain due to lattice constant mismatch.

However, when a reverse bias voltage is applied to the active layer, the active layer can transmit light. This is because the energy band becomes relatively flat and the band gap becomes large when the reverse bias voltage is applied.

As described above, in the semiconductor device 100 according to the present invention, light is emitted from the light emitting portion 5a, and the light modulating portion 5b can output the optical signal by modulating the emitted light according to the change of the voltage.

3 is a perspective view of a semiconductor device according to an embodiment of the present invention. 4 is a cross-sectional view of the region I-I 'of FIG. 5 is an enlarged view of a portion A in Fig.

3 to 5, a semiconductor device 100 according to an embodiment of the present invention includes a light emitting portion 5a, a light modulating portion 5b, and a light emitting portion 5a and a light modulating portion 5b Spaced apart spacer regions 5c. The semiconductor device 100 also includes a substrate 110, a semiconductor structure 120, a first electrode 161 and second electrodes 162a and 162b.

The semiconductor device 100 according to the present invention may be arranged such that the light emitting portion 5a and the light modulating portion 5b are disposed on the substrate 110 together. That is, the light emitting portion 5a may be disposed on one side of the substrate 110, and the light modulating portion 5b may be disposed on the other side of the substrate 110. [ The light emitting portion 5a and the light modulating portion 5b can be separated from each other in the first direction (X axis direction) in which the light travels by the spacer region 5c.

The spacer region 5c may be disposed between the light emitting portion 5a and the light modulating portion 5b. A part of the second conductivity type semiconductor layer 140 corresponding to the spacer region 5c may be etched to electrically isolate the light emitting portion 5a and the light modulating portion 5b. Therefore, the light emitting portion 5a and the light modulation portion 5b can be individually driven by the spacer region 5c. For example, the light emitting portion 5a may be driven by a constant direct current to emit light, and the light modulating portion 5b may be ac driven to modulate the light.

Light emitted from the light emitting layer (active layer) of the light emitting portion 5a can travel in the first direction (X axis direction) corresponding to the long axis due to the difference in refractive index between the upper portion, the lower portion and the side portion of the light emitting layer. That is, the light emitting portion 5a can emit light in the X-axis direction. The absorption layer (active layer) of the light modulation section 5b can absorb or transmit the light incident from the light emitting section 5a in the first direction (X axis direction). Also, the optical modulator 5b can modulate the optical signal emitted to the output terminal. Here, the output terminal may mean the end of the light modulating part 5b located on the opposite side of the light emitting part 5a.

As described above, the semiconductor device 100 according to the present invention can be integrated with the light emitting portion 5a and the light modulating portion 5b on the substrate 110 in a horizontal type. The light emitting portion 5a and the light modulating portion 5b can be separated by the spacer region 5c. At this time, the light emitting portion 5a, the spacer region 5c, and the light modulating portion 5b may be continuously formed along the first direction (X-axis direction). That is, the light emitting portion 5a, the spacer region 5c, and the light modulating portion 5b can be manufactured at the same time.

The light output portion 5a-1 of the light emitting portion 5a and the input end 5b-1 of the light modulating portion 5b facing the light modulating portion of the light emitting portion, Can be aligned to face each other along the first direction (X-axis direction). That is, the semiconductor device 100 according to the present invention can prevent defective alignment between the light emitting portion 5a and the light modulating portion 5b, and can improve optical loss.

The substrate 110 may be a light-transmitting, conductive or insulating substrate. For example, the substrate 110 may include at least one of sapphire (Al2O3), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga2O3.

The substrate 110 includes a first side 111 on which the semiconductor structure 120 is disposed. Here, the light emitting portion 5a may be disposed on one side of the first surface 111, and the light modulating portion 5b may be disposed on the other side.

The semiconductor structure 120 may be disposed on the substrate 110. The semiconductor structure 120 includes a first conductive semiconductor layer 130, a second conductive semiconductor layer 140, and an active layer 140 disposed between the first conductive semiconductor layer 130 and the second conductive semiconductor layer 140, (150).

The first conductive semiconductor layer 130 may be disposed on the substrate 110. The first conductive semiconductor layer 130 may be formed of at least one of Group III-V and Group II-VI compound semiconductors. The first conductivity type semiconductor layer 130 may be formed of a semiconductor material having a composition formula of InxAlyGa1-x-yN (0? X? 1, 0? Y? 1, 0? X + y? The first conductive semiconductor layer 130 may include at least one of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, and AlInN. The first conductive semiconductor layer 130 may be an n-type semiconductor layer doped with an n-type dopant such as Si, Ge, Sn, Se, or Te.

The active layer 150 may be disposed on the first conductive semiconductor layer 130. The active layer 150 is a layer where electrons (or holes) injected through the first conductivity type semiconductor layer 130 and holes (or electrons) injected through the second conductivity type semiconductor layer 140 meet.

The active layer 150 may be a material having a bandgap bending due to spontaneous polarization. The active layer 150 may be formed of at least one of Group III-V and Group II-VI compound semiconductors. When the active layer 150 is implemented as a multi-well structure, the active layer 150 may include a plurality of alternately arranged well layers and a plurality of barrier layers, but is not limited thereto. The active layer 150 may be formed of a semiconductor material having a composition formula of InxAlyGa1-x-yN (0? X? 1, 0? Y? 1, 0? X + y? The active layer 150 may include at least one of a pair of InGaN / GaN, GaN / AlGaN, AlGaN / AlGaN, InGaN / AlGaN, and InGaN / InGaN.

On the other hand, the active layer 150 disposed in the light emitting portion 5a may serve as a light emitting layer. That is, as the electrons and the holes are recombined, the active layer 150 of the light emitting portion 5a can generate light due to a band gap difference according to the formation material of the active layer 150.

Further, the active layer 150 disposed in the light modulating portion 5b can act as a light absorbing layer. That is, the active layer 150 of the light modulating part 5b can absorb or transmit light by the band gap difference according to the material of the active layer 150b as electrons and holes are recombined.

When the active layer 150 of the light modulation part 5b absorbs light, the intensity of light output from the output end may be weak. When the active layer 150 of the light modulating portion 5b transmits light, the intensity of light output from the output end may be sufficient. The active layer 150 of the light modulating part 5b may serve to absorb or transmit light so that an optical signal input from the active layer 150 of the light emitting part 5a can be modulated at the output terminal.

As described above, in the semiconductor device 100 according to the present invention, the active layer 150 may be an optical waveguide. That is, light is generated in the active layer 150 of the light emitting portion 5a, and light is modulated in the active layer 150 of the light modulating portion 5b. The light can move in the first direction (X-axis direction) along the active layer 150 of the light modulation part 5b from the active layer 150 of the light emitting part 5a.

The active layer 150 may have a smaller area than the first conductivity type semiconductor layer 130 when viewed from above. Generally, the larger the area of the active layer 150, the larger the capacitance. Also, as the capacitance value decreases, high-speed operation of the semiconductor device 100 can be realized. Particularly, it is advantageous to have a low capacitance value for the high-speed operation of the light modulation section 5b. Therefore, the active layer 150 may be disposed only on a part of the region of the first conductivity type semiconductor layer 130.

The second conductive semiconductor layer 140 may be disposed on the active layer 150. The second conductive semiconductor layer 140 may have an area corresponding to the active layer 150.

The second conductive semiconductor layer 140 may be formed of at least one of compound semiconductor such as group III-V and group II-VI. The second conductivity type semiconductor layer 140 may be formed of a semiconductor material having a composition formula of InxAlyGa1-x-yN (0? X? 1, 0? Y? 1, 0? X + y? The second conductive semiconductor layer 140 may include at least one of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, and AlInN. The second conductive semiconductor layer 140 may be a p-type semiconductor layer doped with a p-type dopant such as Mg, Zn, Ca, Sr, or Ba.

The semiconductor structure 120 may be formed by partially etching the first conductive semiconductor layer 130, the active layer 150, and the second conductive semiconductor layer 140 in sequence. That is, the first conductivity type semiconductor layer 130, the active layer 150, and the second conductivity type semiconductor layer 140 are arranged to have the same area, and then the second conductivity type semiconductor layer 140, Etching may be done to a portion of the layer 130. Therefore, a portion of the first conductivity type semiconductor layer 130 may be exposed after etching.

3 and 4, the upper part of the semiconductor element 120 (the upper part of the first conductivity type semiconductor layer 130, the active layer 150 and the second conductivity type semiconductor layer 140) And may have a shape protruding from a part of the region of the first conductivity type semiconductor layer 130. Therefore, the area of the active layer 150 is relatively smaller than the area of the first conductivity type semiconductor layer 130, and the high-speed operation of the semiconductor device 100 can be realized due to the reduced capacitance.

3 and 4, the major axis length (X axis direction) and the minor axis length (Y axis direction) of the active layer 150 are arranged to be shorter than the major axis length and minor axis length of the first conductivity type semiconductor layer 130. However, this does not limit the present invention. In addition, the method of manufacturing the semiconductor structure 100 of the present invention is not limited to those described above.

3, the light-emitting portion 5a includes a first-facet 5a-1 and a first-facet 5a-1 facing the optical modulator 5b, And may include two surfaces 5a-2. The light modulation section 5b may include a second-first surface 5b-1 facing the light-emitting section 5a. Here, the length of the first-first surface 5a-1 may be equal to or smaller than the length of the second-first surface 5b-1. The length of the first-second surface 5a-2 may be longer than the length of the first-first surface 5a-1 and the second-first surface 5b-1. This will be described later.

The second conductivity type semiconductor layer 140 may include a second conductive type first semiconductor layer 140a corresponding to the light emitting portion 5a and a second conductive type second semiconductor layer 140b corresponding to the light modulating portion 5b And a second conductive type third semiconductor layer 140c corresponding to the spacer region 5c. The second conductive semiconductor layer 140 may include a first surface 140-1 contacting the active layer 150 and a second surface 140-2 facing the first surface 140-1 .

A groove H having a certain depth from the second surface 140-2 of the second conductivity type semiconductor layer 140 may be formed in the spacer region 5c. That is, the spacer region 5c may be a region where a groove H of a certain depth is formed by etching. The spacer region 5c may mean a region between one end and the other end of the groove H to be etched.

The semiconductor device 100 according to the present invention may have the light emitting portion 5a and the light modulating portion 5b formed integrally on the substrate 110. [ That is, since the optical waveguide (active layer) 150 of the light emitting portion 5a and the light modulating portion 5b are continuously formed, a structure for minimizing the interference between the two may be required. Therefore, a part of the second conductivity type semiconductor layer 140 can be etched to separate the light emitting portion 5a and the light modulating portion 5b. That is, the semiconductor device 100 according to the present invention can form a spacer region 5c by etching a part of the second conductivity type semiconductor layer 140 between the light emitting portion 5a and the light modulating portion 5b have.

5, the thickness of the second conductive type third semiconductor layer 140c may be smaller than the thickness of the first and second semiconductor layers 140a and 140b of the second conductive type. That is, the second conductive type third semiconductor layer 140c may be generally referred to as a portion of the second conductive type semiconductor layer 140 that is etched and has a relatively small thickness. Therefore, the minimum thickness of the etched second conductive type third semiconductor layer 140c may be thinner than the thickness of the unetched second and first conductive semiconductor layers 140a and 140b.

Since the second conductive type third semiconductor layer 140c is formed to be thinner than the second conductive type first and second semiconductor layers 140a and 140b in the second conductive type third semiconductor layer 140c, The resistance may increase. That is, the current flow of the second conductive type third semiconductor layer 140c is minimized, and the first and second semiconductor layers 140a and 140b of the second conductive type can be electrically isolated. Therefore, the flow of current in the first direction can be suppressed by the spacer region 5c, and the electrical interference between the light emitting portion 5a and the light modulating portion 5b can be minimized.

5, the connecting surfaces of the second conductive type third semiconductor layer 140c and the first and second semiconductor layers 140a and 140b of the second conductive type are shown as inclined surfaces. This may be because etching becomes more active in the center portion when the second conductive semiconductor layer 140 of the spacer region 5c is etched. However, the present invention is not limited thereto, and the second conductive type third semiconductor layer 140c may have various shapes after etching.

The minimum thickness T2 of the second conductivity type semiconductor layer 140 may be 0.1 to 0.5 times the maximum thickness T1. The maximum thickness T1 of the second conductivity type semiconductor layer 140 may be a thickness of the second conductivity type first semiconductor layer 140a or the second conductivity type second semiconductor layer 140b . That is, the maximum thickness T1 of the second conductivity type semiconductor layer 140 may be the thickness of the unetched region. In addition, the minimum thickness T2 of the second conductivity type semiconductor layer 140 may be a minimum thickness of the second conductivity type third semiconductor layer 140c. That is, the minimum thickness T2 of the second conductivity type semiconductor layer 140 may be the thickness of the etched region. Therefore, the maximum depth T3 of the second conductive semiconductor layer 140 to be etched may be 0.5 to 0.9 times the maximum thickness T1.

If the minimum thickness T2 of the second conductivity type semiconductor layer 140 is thinner than 0.1 times the maximum thickness T1, a sufficient optical path may not be secured. Specifically, light can be spread not only in the active layer 150 but also in a part of the first and second conductivity-type semiconductor layers 130 and 140 adjacent to the active layer 150. This may be because the light is diffusible. That is, light travels along a part of the active layer 150 and the first and second conductive semiconductor layers 130 and 140 adjacent thereto. Therefore, when the thickness of the second conductive type third semiconductor layer 140c is too small, the light path may become too small, resulting in optical loss. Also, the thickness of the second conductive type third semiconductor layer 140c may become too thin, and the active layer 150 may be damaged.

If the minimum thickness T2 of the second conductivity type semiconductor layer 140 is thicker than 0.5 times the maximum thickness T1, electrical interference may occur between the light emitting portion 5a and the light modulating portion 5b. That is, the second conductive type third semiconductor layer 140c may not have a resistance value enough to prevent interference between the light emitting portion 5a and the light modulating portion 5b.

The width D1 of the second conductive type third semiconductor layer 140c may be 5 to 50 占 퐉. Here, the width D1 of the second conductive type third semiconductor layer 140c may be the width D1 of the spacer region 5c. That is, the width D1 of the second conductive type third semiconductor layer 140c may be a distance between the light emitting portion 5a and the light modulating portion 5b.

If the width D1 of the second conductive type third semiconductor layer 140c is smaller than 5 占 퐉, insulation between the light emitting portion 5a and the light modulating portion 5b may not be achieved. That is, the distance between the light emitting portion 5a and the light modulating portion 5b is too close to cause electrical interference between the two portions.

If the width D1 of the second conductive type third semiconductor layer 140c is larger than 50 占 퐉, light loss may occur between the light emitting portion 5a and the light modulating portion 5b. That is, the distance between the light-emitting portion 5a and the light-modulating portion 5b is too large to cause optical loss.

The first electrode 161 may be disposed on the first conductive semiconductor layer 130. Specifically, the first electrode 161 may be disposed in a region of the first conductivity type semiconductor layer 130 where the active layer 150 and the second conductivity type semiconductor layer 140 are not disposed. The first electrode 161 may be disposed on a portion of the first conductive semiconductor layer 130 exposed after etching. Although the first electrode 161 is illustrated as overlapping the light emitting portion 5a, the light modulating portion 5b, and the spacer region 5c in the second direction (Y axis) in the drawing, the present invention is not limited thereto.

The first electrode 161 may be electrically connected to the first conductive semiconductor layer 130. The first electrode 161 may be selected from Ti, Ru, Rh, Ir, Mg, Zn, Al, In, Ta, Pd, Co, Ni, Si, Ge, Ag and Au and alloys thereof.

The second electrodes 162a and 162b may be disposed on the semiconductor structure 120. The second electrodes 162a and 162b may be formed of the same material as the first electrode 161.

The second electrodes 162a and 162b may include a second-first electrode 162a and a second-second electrode 162b. Here, the second-1 electrode 162a may be disposed in the light-emitting portion 5a, and the second-second electrode 162b may be disposed in the light-modulating portion 5b. The second-first electrode 162a and the second-second electrode 162b may be spaced apart from each other.

The second-first electrode 162a may cover the entire upper surface of the light-emitting portion 5a. Accordingly, the semiconductor structure corresponding to the light emitting portion 5a may be disposed inside (lower) of the second-1 electrode 162a. And the second -2 electrode 162b can cover the entire upper surface of the light modulation section 5b. Therefore, the semiconductor structure corresponding to the light modulating portion 5b can be disposed inside (lower) of the second -2 electrode 162b. That is, the second-1 electrode 162a may be disposed on the second conductive type first semiconductor layer 140a, and the second-second electrode 162b may be disposed on the second conductive type second semiconductor layer 140b. have.

The second -2 electrode 162b may include a first region 162b-1 facing the second-1 electrode 162a. In this case, the first area 162b-1 may be the one closest to the second-1 electrode 162a of the second -2 electrode 162b and facing the second-1 electrode 162a.

The second-1 electrode 162a may include a second region 162a-1 facing the second-second electrode 162b. In this case, the second region 162a-1 may be the one closest to the second-second electrode 162b of the second-first electrode 162a and facing the second-second electrode 162b. That is, the second region 162a-1 and the first region 162b-1 may be arranged to face each other.

The second-1 electrode 162a may further include a third region 162a-2 facing the second region 162a-1 on the opposite side of the second region 162a-1. The third region 162a-2 may be a surface disposed farthest from the second-second electrode 162b of the second-first electrode 162a. The third region 162a-2 and the second region 162a-1 may be planes disposed on one side and the other end of the second -1 electrode 162a in the X-axis direction.

The length W1 of the first area 162b-1, the length W2 of the second area 162a-1, and the length W3 of the third area 162a-2 satisfy the relation of W3> W1? W2 Lt; / RTI > The same can be applied to the lengths of the second conductivity type semiconductor layer 140 and the active layer 150 disposed under the second and second electrodes 162a and 162b. In detail, the active layer 150, the second conductivity type semiconductor layer 140, and the second and first and second electrodes 162a and 162b have the same area and can be sequentially stacked. This will be described later.

The second-first electrode 162a and the second-second electrode 162b may be respectively disposed in mutually spaced regions of the second conductivity type semiconductor layer 140 and electrically isolated from each other. That is, the second electrodes 162a and 162b electrically connected to the second conductivity type semiconductor layers 140a and 140b of the light emitting portion 5a and the light modulating portion 5b are independently driven by the spacer region 5c . On the other hand, the first electrode 161 electrically connected to the first conductive semiconductor layer 130 may serve as a common electrode of the light emitting portion 5a and the light modulating portion 5b.

An electrode pad (not shown) may be further disposed on the first electrode 161 and the second electrodes 162a and 162b. The semiconductor device 100 may be driven by being connected to an external device by an electrode pad.

An insulating layer (not shown) may be disposed in an area of the semiconductor device 100 where the electrodes 161, 162a, and 162b and the reflective layer 270 are not disposed.

6A to 6C are plan views according to various modifications of the semiconductor device according to an embodiment of the present invention.

6A is a plan view of the semiconductor device 100 shown in FIG. Here, for convenience, the first electrode 161 is omitted. Hereinafter, the lengths of the light emitting portion 5a and the light modulating portion 5b in the second direction (Y-axis direction) will be described with reference to FIGS. 3 to 5 described above.

6A, a second-1 electrode 162a may be disposed on the light-emitting portion 5a, and a second-second electrode 162b may be disposed on the light-modulating portion 5b.

The second -2 electrode 162b may include a first region 162b-1. Here, the first region 162b-1 may be a surface of the second-second electrode 162b facing the second-first electrode 162a.

The second-1 electrode 162a may include a second region 162a-1 and a third region 162a-2. Here, the second region 162a-1 may be a surface facing the second-second electrode 162b of the second-first electrode 162a. That is, the second region 162a-1 and the first region 162b-1 may be arranged to face each other. The third region 162a-2 may be a surface of the second-1 electrode 162a disposed on the opposite side of the second region 162a-1. That is, the second area 162a-1 and the third area 162a-2 may be the surfaces disposed at both ends of the second-1 electrode 162a in the first direction (X-axis direction).

3, the light-emitting portion 5a is provided on the first surface 5a-1 and the first surface 5a-1 facing the light modulating portion 5b, And the first and second surfaces 5a-2. The first-first surface 5a-1 and the first-second surface 5a-2 may each mean a surface disposed at both ends of the light emitting portion 5a in the first direction (X-axis direction) . The light modulation section 5b may include a second-first surface 5b-1 facing the light-emitting section 5a. The second-first surface 5b-1 may mean a surface disposed at one end of the light modulating portion 5b in the first direction.

The first-first surface 5a-1 and the first-second surface 5a-2 of the light emitting portion 5a are formed on the upper portion of the first conductivity type semiconductor layer 130 disposed in the light emitting portion 5a, The active layer 150, the first region 140a, and the second-1 electrode 162a. The second-1 surface 5b-1 of the optical modulator 5b is formed on the upper portion of the first conductivity type semiconductor layer 130 disposed in the light modulating portion 5b, the active layer 150, 140b and the second-second electrode 162b.

In addition, since the upper portion of the first conductivity type semiconductor layer 130, the active layer 150, and the first region 140a of the light emitting portion 5a are etched together, they can have the same area. At this time, the second-1 electrode 162a disposed so as to cover the light-emitting portion 5a may have the same area. In addition, the upper portion of the first conductivity type semiconductor layer 130, the active layer 150 and the second region 140b of the optical modulator 5b are etched together, so that they can have the same area. At this time, the second-second electrode 162b disposed to cover the light modulation section 5b may have the same area. Therefore, the relationship with respect to their lengths can also be made equal to each other.

That is, the first-first surface 5a-1 includes the second area 162a-1, the first-second surface 5a-2 includes the third area 162a-2, 1 plane 5b-1 may include a first area 162b-1. Since the respective layers constituting the light emitting portion 5a and the light modulating portion 5b have areas corresponding to each other, the second-1 electrode 162a and the second-2 electrode 162b ) Will be mainly described.

The first region 162b-1 has a first length W1 and the second region 162a-1 has a second length W2 and the third region 162a-2 has a third length W3 ). Here, the first, second, and third lengths W1, W2, and W3 may be lengths in the second direction (Y-axis direction). Further, the second direction may be a direction perpendicular to the first direction (X-axis direction) in which the light advances. The second direction may be a direction perpendicular to the third direction (Z-axis direction) in which the first conductivity type semiconductor layer 130, the active layer 150, and the second conductivity type semiconductor layer 140 are disposed.

On the other hand, the first length W1 corresponds to the upper portion of the first conductivity type semiconductor layer 130 disposed on the second-first surface 5b-1, the active layer 150, and the second conductive type second semiconductor layer 140b. . The second length W2 is a width of the active layer 150 and the width of the second conductive type first semiconductor layer 140a on the first conductive type semiconductor layer 130 disposed on the first- It is possible. The third length W3 is the width of the active layer 150 and the second conductive type first semiconductor layer 140a on the first conductive type semiconductor layer 130 disposed on the first-second surface 5a- It is possible.

The first, second, and third lengths W1, W2, and W3 may have a relationship of W2? W1 < W3. At this time, the width of the spacer region 5c may be the same as the second length W2. However, this does not limit the present invention.

The semiconductor device 100 according to the present invention can reduce the area of the active layer 150 in order to reduce the capacitance. Particularly, the first length W1 of the light modulation part 5b is made small, so that high-speed modulation can be performed. At this time, the light emitting portion 5a and the light modulating portion 5b may be connected to each other by an optical waveguide (active layer). Therefore, the second length W2 of the first-first surface 5a-1 on which light is emitted from the light-emitting portion 5a may be formed to correspond to the first length W1.

That is, the second length W2 may be equal to or less than the first length W1. If the second length W2 is larger than the first length W1, the width of the optical waveguide of the light emitting portion 5a becomes larger, so that light loss may occur. In other words, the width of the light output portion of the light emitting portion 5a is larger than the width of the input end of the light modulating portion 5b, and light loss may occur.

On the other hand, the second length W2 may have a value of 0.1 times or more of the first length W1. If the second length W2 is smaller than 0.1 times the first length W1, the width of the light outputting portion 5a-1 of the light emitting portion 5a is significantly reduced, and the light intensity can be weakened.

On the other hand, the operating voltage of the light emitting portion 5a may be inversely proportional to the area of the light emitting portion 5a. That is, when the second length W2 is reduced, the area of the light emitting portion 5a is relatively small, so that the operating voltage and consumed power increase during driving the device, and heat may be generated. This may lead to deterioration of the device and shortening of its service life. In order to prevent this, the third length W3 may have a value larger than the second length W2. That is, as the first-second surface 5a-2 is formed longer, it is possible to compensate for the decrease in area due to the short formation of the first-first surface 5a-1.

The third length W3 may be 2 to 50 times the second length W2. When the third length W3 is smaller than twice the second length W2, the operating voltage of the light emitting portion 5a can be increased. If the third length W3 is larger than 50 times the second length W2, the entire area of the device may be enlarged to be inefficient.

In addition, the third length W3 may have a larger value than the first length W1. When the third length W3 is equal to or less than the first length W1, the area of the light emitting portion 5a can be significantly reduced. That is, the area of the light emitting portion 5a is reduced due to the second length W2, which is smaller than the third length W3, so that the operating voltage can be greatly increased.

Meanwhile, in the first modification according to FIG. 6A, the light emitting portion 5a may be arranged in a tapered structure. That is, the width of the light emitting portion 5a from the third region 162a-2 to the second region 162a-1 can be gradually reduced. Here, the length W3 of the third area 162a-2 is larger than the length W2 of the second area 162a-1. The length W1 of the first area 162b-1 of the light modulation part 5b is larger than the length W2 of the second area 162a-1. However, the present invention is not limited to such a form, and any form satisfying W3 > W1 &gt;

6B, the light emitting portion 5a is arranged to have the same width in the first direction from the third region 162a-2, and thereafter the second region 162a- 1). The width of the light modulating portion 5b may be larger than the second region 162a-1 and smaller than the third region 162a-2. That is, the first length W1, the second length W2, and the third length W3 in FIG. 6B may have a relationship of W3> W1? W2.

Referring to FIG. 6C, the third region 162a-2 has a tapered structure similar to FIG. 6A, but may have a curved shape. That is, since the third length W3 has a curved shape, it can be longer than the third-first length W3 'in a straight line shape. In this case, since the area of the light emitting portion 5a is larger, the effect of reducing the operating voltage and consumed power can be increased. 6C, the first length W1, the second length W2, and the third length W3 may have a relationship of W3> W1? W2, though the shape is different.

As described above, the semiconductor device according to the present invention may have a relationship of W3> W1? W2 where the first length W1, the second length W2, and the third length W3. In particular, the light emitting portion 5a and the light modulating portion 5b may be arranged in any form if they satisfy this relationship.

On the other hand, in the drawing, the width of the light emitting portion 5a in the first direction is longer than the width of the light modulating portion 5b. However, the present invention is not limited to this.

The semiconductor device according to the present invention is configured such that the second length W2 of the light output portion of the light emitting portion 5a (the first surface 5a-1 or the second region 162a-1) Or less than the first length W1 of the input end (the second surface 1 (5b-1) or the first area 162b-1) of the first area 162b. Therefore, it is possible to increase the intensity of light incident on the light modulator 5b, and to increase the signal stability and transmission distance.

In addition, the third length W3 of the first-second surface 5a-2 (third area 162a-2) of the light emitting portion 5a is defined as the first-first surface 5a-1 (162-a)). Therefore, it is possible to further increase the area of the light emitting portion 5a, thereby lowering the operating voltage and consuming power during driving. Further, the heat generation can be reduced, and the reliability and lifetime of the light emitting portion 5a can be improved.

FIG. 7 is an enlarged view of a region corresponding to portion A of FIG. 4 among semiconductor devices according to another embodiment of the present invention. FIG.

Referring to FIG. 7, a semiconductor device according to another embodiment of the present invention may include a light emitting portion 5a, a light modulating portion 5b, and a spacer region 5c. The semiconductor device may also include a substrate 110 (FIG. 3), a semiconductor structure 120, electrodes 161, 162a, 162b (FIG. 3), and a reflective layer 270. That is, the semiconductor device according to another embodiment of the present invention is the same as the previous embodiment except that the reflection layer 270 is further disposed. Therefore, only the structure of the reflective layer 270 will be described below.

The reflective layer 270 may be disposed on the second conductive semiconductor layer 140 disposed between the light emitting portion 5a and the light modulating portion 5b. The reflective layer 270 may be disposed on the etched region of the second conductive semiconductor layer 140. That is, the reflective layer 270 may be disposed on the second conductive type third semiconductor layer 140c of the spacer region 5c. The reflective layer 270 may be disposed not only on the second conductive type third semiconductor layer 140c but also on a portion of the second and first electrodes 2 and 2-2. However, the present invention is not limited to this.

The reflective layer 270 may be disposed by stacking at least two layers having different refractive indices. Further, at least two layers having different refractive indices may be alternately laminated at least once. The reflective layer 270 may be a selected one of DBR (Distribute Bragg Reflector) or OBR (Omni-directional Reflector), or a combination thereof.

Since the reflective layer 270 is disposed on the second conductive type third semiconductor layer 140c, light loss in the second conductive type third semiconductor layer 140c having a relatively small thickness can be minimized. Specifically, light can be diffused not only to the active layer 150 but also to a part of the periphery thereof. At this time, the light passing through the spacer region 5c may be scattered to the outside due to the discontinuity of the refractive index and the structure between the light emitting portion 5a and the light modulating portion 5b. In addition, since the thickness of the second conductive type third semiconductor layer 140c disposed in the spacer region 5c is relatively thin, light may be scattered to the outside and may be lost. Therefore, by arranging the reflection layer 270 in the spacer region 5c, the light scattered to the outside can be minimized.

In this way, the semiconductor device 100 according to the present invention can minimize light loss by allowing light to be reflected internally through the reflection layer 270. Further, by improving the light output, the power consumption can be reduced and the life of the light emitting portion can be improved.

8 is a graph showing a current value according to a voltage of a semiconductor device and its comparative example according to an embodiment of the present invention.

In the case of Embodiment 1 (N1), the semiconductor device is implemented so that the first length W1, the second length W2, and the third length W3 have a relation of W3> W1? W2 according to FIG. 6A of the present invention It is. In the case of Comparative Example 1 (N2), the first length W1, the second length W2, and the third length W3 are all the same, thereby realizing a semiconductor device. Here, the first lengths of the first embodiment (N1) and the first comparative example (N2) may be the same.

Referring to FIG. 8, it can be seen that the voltage value of Example 1 (N1) is smaller than the voltage value of Comparative Example 1 (N2) at the same current value. That is, in Example 1 (N1), the area of the light-emitting portion 5a is relatively larger than that in Comparative Example 1 (N2), so that the resistance can be reduced.

As described above, the semiconductor device according to the present invention may have different lengths of the first-first surface 5a-1 and the first-second surface 5a-2 of the light emitting portion 5a. That is, the length of the first-second surface 5a-2 may be longer than the length of the first-first surface 5a-1. Therefore, the light emitting portion 5a of the present invention can have a wider area than that formed by the same lengths of the 1-1, 1-2 surfaces. In this manner, the light emitting device of the present invention can lower the operating voltage and the consumed power at the time of driving. Further, the heat generation phenomenon is improved, and the lifetime and reliability of the device can be improved.

9 is a conceptual diagram of an optical transmission module according to the present invention.

9, the optical transmission module 5 according to the present invention may include a semiconductor device 100, a lens module 13, and an output waveguide 15.

The semiconductor device 100 may include the structure described above.

The lens module 13 may be disposed between the semiconductor device 100 and the output waveguide 15. The lens module 13 may include a function of providing an optical signal provided from the semiconductor device 100 to the output waveguide 15.

The output waveguide 15 can output the optical signal provided through the lens module 13 to the outside. The output waveguide 15 may include a clad and a core, and may be arranged in parallel with the lens module 13 and the semiconductor device 100 in the vertical direction.

The optical transmission module 5 may include a first cover portion, a second cover portion and a third cover portion 11A, 11B, and 11C. The first, second and third cover parts 11A, 11B and 11C may cover the semiconductor device 100, the lens module 13 and the output waveguide 15, respectively, but are not limited thereto.

The semiconductor device according to the present invention can be used for a high-speed optical communication of 10 Gbps or less of 100 m or less and for a short distance high-speed optical communication such as a home network or an automobile. Further, the semiconductor device according to the present invention can improve the manufacturing cost of a general laser diode (light emitting portion) and the aline reliability problem of the laser diode and the optical modulator (light modulation portion).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

100; A semiconductor element 5a; The light-
5b; An optical modulator 5c; Spacer region
5a-1; 1-1 sheet 5a-2; Pages 1-2
5b-1; 2-1 surface 110; Board
120; Semiconductor structure 130; The first conductive semiconductor layer
140; A second conductive semiconductor layer 140a; The second conductive type first semiconductor layer
140b; A second conductive type second semiconductor layer 140c; The second conductive type third semiconductor layer
150; An active layer 161; The first electrode
162a; A second-1 electrode 162b; 2-2 electrode
162a-1; A second region 162a-2; The third region
162b-1; A first region 270; Reflective layer

Claims (13)

A semiconductor structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer;
A first electrode disposed on the first conductive semiconductor layer;
A second-1 electrode disposed on the second conductive type semiconductor layer; And
And a second -2 electrode disposed on the second conductivity type semiconductor layer and spaced apart from the second -1 electrode,
The thickness of the second conductivity type semiconductor layer between the second-first electrode and the second-second electrode is preferably set to a thickness of the second conductivity type semiconductor layer vertically overlapped with the second-first electrode and the second- Thinner,
The second electrode includes a first region facing the second electrode, the first electrode having a distance closest to the second electrode, and the second electrode includes a second electrode facing the second electrode, And a second region closer to the second electrode than the second electrode,
Wherein a width (W1) of the first region has a relationship of a width (W2) of the second region and W1? W2. The method according to claim 1,
And a width (W2) of the second region is 0.1 times or more of a width (W1) of the first region. The method according to claim 1,
And the second-1 electrode further includes a third region disposed at the opposite end of the second region,
And the width (W3) of the third region has a relationship of a width (W1) of the first region and W3 > W1. The method of claim 3,
And the width (W3) of the third region is 2 to 50 times the width (W2) of the second region. The method according to claim 1,
The second-first electrode and the second-electrode are spaced apart from each other in the first direction,
And W1 and W2 are lengths in a second direction perpendicular to the first direction. 6. The method of claim 5,
Wherein the first conductivity type semiconductor layer, the active layer, and the second conductivity type semiconductor layer of the semiconductor structure are arranged in a third direction,
And the third direction is perpendicular to the second direction. The method according to claim 1,
The second conductivity type semiconductor layer may include a first conductivity type semiconductor layer,
A second conductive type first semiconductor layer in which the second-1 electrode is disposed;
A second conductive type second semiconductor layer in which the second -2 electrode is disposed; And
And a second conductive type third semiconductor layer disposed between the second conductive type first semiconductor layer and the second conductive type second semiconductor layer. 8. The method of claim 7,
The semiconductor device may further include: a light emitting portion; An optical modulation unit spaced apart from the light emitting unit; And a spacer region disposed between the light emitting portion and the light modulating portion,
The light emitting portion may include the second conductive type first semiconductor layer, the light modulating portion may include the second conductive type second semiconductor layer, and the spacer region may include a semiconductor containing the second conductive type third semiconductor layer, device. 9. The method of claim 8,
Wherein the semiconductor structure corresponding to the light emitting portion is disposed inside the second-1 electrode, and the semiconductor structure corresponding to the light modulating portion is disposed inside the second-second electrode. 9. The method of claim 8,
The second-1 electrode is disposed so as to cover the entire upper surface of the light emitting portion, and the second -2 electrode is disposed so as to cover the entire upper surface of the light modulating portion. 8. The method of claim 7,
And a reflective layer disposed on the second conductive type third semiconductor layer. 12. The method of claim 11,
And the reflective layer is disposed so as to cover a part of the second-first electrode and the second-electrode. The method according to claim 1,
Wherein the active layer is disposed in a partial region on the first conductive type semiconductor layer.

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