Luminous element

The application is filed 26 July 2007 section 200710138136.9 invention applied for Patent application.

Technical Field

The invention relates to a light-emitting element, in particular to a structure of the channel of the semiconductor layer has a light-emitting diode element.

Background Art

Light-emitting diode element is a widely-used light source. Compared with the traditional incandescent bulb or fluorescent tube, light emitting diode in addition to a power-saving and long service life characteristics of excellent, the cost advantage of integrity, thus gradually replace the traditional light source, and applied in all kinds of different fields, such as traffic sign, backlight module, street lamp lighting, medical equipment, and other industries.

As the light-emitting diode light source for the brightness of the application and development of increasingly high demand, how to increase the luminous efficiency and improve its brightness, the industry has become an important direction. Currently known method of using a transfer technology is one of the original base plate provided with a light-absorbing characteristic of removing the growth substrate, and is converted into a has a light-transmitting substrate or heat dissipation characteristics, so can greatly improving the light emitting efficiency and to improve the brightness.

Figure 9 in order to utilize the known base plate transfer technology the resulting general InGaN light emitting diode element, the structure of the bottom: p electrode 41, the permanent substrate 42, the connecting layer 43, the light-emitting laminate 44 (containing p-type semiconductor layer 443, the luminescent layer 442 and n-type semiconductor layer 441), n-type ohmic contact layer 45, n electrode 46. The above-mentioned structure by a metal bond is formed by the process steps of the vertical structure, in order to make the n electrode 46 with the n-type semiconductor layer 441 producing ohmic contact on, the originally n-type semiconductor layer 441 non doping layer is removed (Figure not shown), to form the n-type ohmic contact layer 45 on its upper, the n electrode 46 formed on the n-type ohmic contact layer 45 above. However, because this structure shall be removed is not doped, to the problem of excessive high driving voltage.

Content of the invention

The invention relates to a light emitting element, includes semiconductor layer, the ohmic contact layer and at least one electrode, and reaction ion beam etching (  etching   ion-beam Reactive) technology, forming through the light-emitting element to the semiconductor layer of the channel, the metal filled in the channel, to form a channel structure, the two sides of the semiconductor layer electrically connecting the ohmic contact layer and the electrode, in order make the electric current through the electrode, the structure of the channel, the ohmic contact layer, convey to the semiconductor layer, drive the whole light-emitting element. The design of the through the channel structure, can obtain a good ohmic contact and better light emitting diode element of the light-emitting efficiency.

In one embodiment of the invention, proposes a first utilize base plate transfer technology, the light-emitting element the growth substrate substituted for the conductive base plate, and then by reactive ion beam etching (  etching   ion-beam Reactive) technology, the light-emitting laminate of n-type semiconductor layer etching to form the n-type channel, and the above-mentioned n-type channel is filled with metal, forming n type channel structure and n electrode, the two sides of the n-type semiconductor layer of the n-type ohmic contact layer for electrically connecting the electrode to produce n, and obtained the vertical type light-emitting diode element.

Another embodiment of the present invention, the structure of another light-emitting element, the base plate first transfer technology, the light-emitting element the growth substrate substituted for the heat-dissipating base plate, and then by reactive ion beam etching (  etching Reactive ion-beam) technology, at the same time in the light-emitting laminate of n-type semiconductor layer and a P-type semiconductor layer, the etching is formed respectively with the n-type channel p-shaped channel; and in the n-type channel p-shaped channel between the, n-type semiconductor layer through the etching to form the luminescent layer of the barrier channel, used as an electrical insulation. Through the n-type channel, p-shaped channel and the barrier design of channel, can obtain a good ohmic contact characteristics of the horizontal light-emitting diode.

Another embodiment of the present invention, in the form as described above is of the vertical or the horizontal light emitting diode element, the n-type semiconductor layer adjacent to the light output surface by roughening, to form a rugged roughened surface, so can increase the light extraction efficiency of the light-emitting element.

Description of drawings

Figure 1 is of the embodiment of the invention 1st 1st schematic diagram of process steps.

Figure 2 is of the embodiment of the invention 1st 2nd schematic diagram of process steps.

Figure 3 is the embodiment of the invention 1st 3rd schematic diagram of process steps.

Figure 4 is the embodiment of the invention 1st 4th schematic diagram of process steps.

Figure 5 is the embodiment of the invention 1st 5th schematic diagram of process steps.

Figure 6 of the 2nd embodiment of this invention the light-emitting diode structure diagram.

Figure 7 is the structure diagram of the backlight module.

Figure 8 the lighting device for the structure diagram of the invention.

Figure 9 is a known structure diagram of the light-emitting diode.

Note the Figure mark

100 vertical type light-emitting diode element   11 growth substrate

12 semiconductor light-emitting laminate   121   n-type semiconductor layer

122 light-emitting layer   123   p-type semiconductor layer

13   n-type ohmic contact layer   14 transparent conductive layer

15 dielectric layer   16 metal reflecting layer

17   n-type channel   18   n electrode

21 permanent substrate   22 connecting layer

200 horizontal light-emitting diode element   31   p-type ohmic contact layer

32   p-shaped channel   33   p electrode

34 separates the channel   700 backlight module device

710 light source device   711 light-emitting diode component

720 optical device   800 lighting device

810 light source device   811 light-emitting diode component

820 power supply system   830 control element

Mode of execution

Fig. 5 display according to the invention of the embodiment of the 1st vertical type light-emitting diode element 100. The embodiments utilize base plate transfer technology, mainly comprises a chip bonding (wafer   bonding) process, to remove the base plate (substrate   lift-off) process and reaction ion beam etching (  ion-beam Reactive   etching) process, which is made of the vertical type light-emitting diode. Correlation steps as shown in Figure 1-Figure 5 shows, in detail as follows.

Figure 1 1st process steps shown, light-emitting structure is formed first, comprising a growth substrate 11, the semiconductor light-emitting laminate 12, n-type ohmic contact layer 13, a transparent conductive layer 14, the dielectric layer 15 and the metal reflecting layer 16 ; wherein the light-emitting stack 12 also includes the n-type semiconductor layer 121, light-emitting layer 122 and p-type semiconductor layer 123. Furthermore, the permanent substrate 21 is formed on the layer 22. As mentioned above the growth substrate 11, for example, a sapphire substrate (  substrate Sapphire), to the growth substrate 11 is formed first on the buffer layer, for example, AlN, GaN or AlGaN, so can make the formed on the upper surface of the nitride semiconductor light-emitting laminate 12, for example, GaN, AlGaN or InAlGaN, in the crystal growth process without generating a large amount of crystal lattice dislocations, or lattice defects (dislocation) (defect); transparent conductive layer 14 can be indium tin oxide (ITO), not only can effectively disperse current, and has a light-transmitting characteristic, the light extraction efficiency can be increased; the dielectric layer 15 can be an inorganic dielectric material, such as silicon dioxide (SiO₂), alumina (Al₂ O₃), silicon nitride (SiN_x), or spin-on-glass (  glass spin-on), also can be an organic dielectric material, such as epoxy resin (epoxy), poly-amide (polyimide) or BCB (benzocyclobutene) resin material such as; n-type ohmic contact layer 13, can be the n-type semiconductor layer 121 producing ohmic contact material, such as indium tin oxide (ITO) or aluminum (Al), metal such as nickel (Ni); metal reflecting layer 16, is provided with a high-reflectivity conductive material, for example aluminum (Al) or silver (Ag); permanent substrate 21, the substrate having a conductive property, such as a silicon substrate, the copper base plate.

Chart 2 2nd process steps shown, use of the connection process is, through the connection of the two base plates 22 are integrally connected; wherein the connecting process can be a direct connection or metal connection. Direct connection is generally under the high-temperature condition (> the 400 [...]), imposing a fixed secondary pressure, the two sides of the connecting interface material is molten together. Metal connection is on the interface of the two is, their respective metal layer is formed first, and then subjected to lower temperature (200 the the [...] -300 [...]) and fixed auxiliary pressure, is connected with the two metal layers.

Figure 3 3rd process steps shown, the base plate is removed is the growth substrate 11 is removed. Wherein the base plate to remove technology as the laser lift-off technology, is an excimer laser (  laser Excimer) by the growth substrate 11 and the semiconductor light-emitting laminate 12 opposite to the incident surface. Most of the laser energy on the growth substrate of the buffer layer at the interface between the growth substrate is absorbed, and the absorbed laser energy can be decomposed buffer layer, such as aluminum nitride, thereby achieving the purpose of removing the base plate.

Figure 4 4th process steps shown, is to utilize the reaction ion beam etching (  Ion-beam Etching Reactive; RIE) technique, the n-type semiconductor layer 121 etched to form n-type channel 17, to expose the n-type ohmic contact layer 13. Wherein the reaction ion beam etching (  etching   ion-beam Reactive) has many advantages, such as high resolution line width (Resolution), selectively good, fast etching rate, and independent control of the reaction parameters can be the problem of the residue-free, in the semiconductor manufacturing process is therefore gradual by reaction ion beam etching instead of wet etching. This embodiment in order to inductively coupled plasma reactive ion etching system of performing dry etching (ICP-RIE), and to method for analysis of etch parameters, by changing the reaction gas (BCl₃/Ar) flow, pressure, induction coupled plasma ICP (Inductively   coupled   plasma) power and RF power (that is, bias DC-bias), identify them and etching rate, etching selectivity, directional etching, etching the surface and the impact of the smoothness of the photoresist, in order to obtain the best etching parameter, etch the n-type channel 17.

Figure 5 5th process steps shown, the n-type channel system 17 to the metal fill, forming n type channel structure and n electrode 18, the n-type ohmic contact layer 13 and the n electrode 18 is connected with the electricity produced. At the same time the permanent substrate 21 below the of the, form the metal layer as p electrode 23.

By utilizing the above-mentioned process step of forming the vertical type light-emitting diode element 100, the n electrode upward vertical type light-emitting diode element structure. This embodiment is using n-type channel 17 design, so that the follow-up the formed n electrode 18, the n-type ohmic contact layer 13 to form a good ohmic contact, and the common electrode and n ohmic contact of the n-type semiconductor layer, and a high driving voltage.

Another embodiment of the present invention, in the form as described above is of the vertical type light-emitting diode element 100 the rear, and then close to the n-type semiconductor layer 121 the light incident surface rough, forming a rough roughened surface, so can increase the light extraction efficiency of the light-emitting element.

Figure 6 2nd embodiment of display according to the invention the horizontal light-emitting diode element 200. The embodiment of the main process steps of the process generally the same as the 1st embodiment, the connecting process is used, the substrate removal process and reaction ion beam etching, horizontal formed by the light-emitting diode element 200, its structure is as shown, the following is a description in detail.

2nd embodiment horizontal light-emitting diode element 200, its structure comprising in order from bottom to top: the permanent substrate 21, connecting layer 22, the metal reflecting layer 16, the dielectric layer 15, a transparent conductive layer 14, the light-emitting laminate 12 (comprising n-type semiconductor layer 121, light-emitting layer 122 and p-type semiconductor layer 123), n-type ohmic contact layer 13 and p-type ohmic contact layer 31 ; then, using reaction ion beam etching technique, forming through n-type semiconductor layer 121 of the n-type channel 17, and then to the metal fill, forming n type channel structure and n electrode 18, the n-type ohmic contact layer 13 and the n electrode 18 is connected with the electricity produced. And another etching to form through the semiconductor light-emitting laminate 12 p-shaped channel of the 32, and with the metal fill, p-shaped channel structure formed and p electrode 33, the p-type ohmic contact layer 31 and p electrode 33 is connected with the electricity produced. Finally, the n-type channel 17 and p-shaped channel 32 between, through etching to form n-type semiconductor layer 121 and the light-emitting layer 122 of the barrier channel 34, used as an electrical insulation. Through the above-mentioned n-type channel 17, p-shaped channel 32 and separate channel 34 design, possible to obtain a good ohmic contact characteristics with horizontal light-emitting diode structure. Wherein the permanent substrate with a heat dissipation characteristic of the base plate, so that the light-emitting diode element, good heat radiating effect can be obtained, increase the component life.

Another embodiment of the present invention, as described above in the form of horizontal light emitting diode element 200 back, close to the n-type semiconductor layer 121 the light incident surface rough, forming a rough roughened surface, so can increase the light extraction efficiency of the light-emitting element.

A of this invention embodiment, as stated above the horizontal light-emitting diode element 200, wherein the dielectric layer 15 (Phosphor) of the phosphor powder containing colored conversion function, thus saving the metal reflecting layer 16, and using the transparent layer 22 and the transparent permanent substrate 21 ; in this way, the light-emitting laminate 12 of the light, through the dielectric layer 15 of the phosphor powder in the color conversion, the original colour light from color light, through the transparent permanent substrate 21 light output. Is, for example, may issue a blue wavelength light-emitting laminate 12, a dielectric layer with a yellow fluorescent powder 15 combined, they can produce white light, and the transparent permanent substrate 21 light output. Or, the upper can also be of the horizontal light-emitting diode element 200 of the metal reflecting layer 16, in order to satisfactory color conversion function to replace the color conversion layer, is matched with a transparent connecting layer 22 and the transparent permanent substrate 21, the above embodiment can be reached also effective, produce a mixed light, through the transparent permanent substrate 21 light output.

Fig. 7 display in accordance with this invention the backlight module structure. Wherein the backlight module device 700 comprising: by the present invention the above-mentioned arbitrary embodiment of the light-emitting diode element 711 of the light source device 710 ; optical device 720 is arranged in the light source device 710 on the light path, the light as the appropriate light output after processing; power supply system and 730, to provide the above light source device 710 the required power supply.

Figure 8 shows the structure of the lighting device in accordance with this invention. The above-mentioned lighting device 800 can be a car lamp, street lamp, flashlight, street lamp, indicator lamp, and so on. Wherein the lighting device 800 comprising: light source device 810, is composed of the invention above-mentioned arbitrary embodiment of the light-emitting diode element 811 formed by the; power supply system 820, provides a light source device 810 the required power supply; and control element 830 to control the current input light source device 810.

Although the invention has been described by the above embodiment, but its not in order to limit the scope of, the invention. For the present invention for the various modification and alteration, are not escapes this spirit and scope of the invention.