CN1282984A - Blue-light LED using sapphire as substrate and its making technology - Google Patents
Blue-light LED using sapphire as substrate and its making technology Download PDFInfo
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- CN1282984A CN1282984A CN99111040A CN99111040A CN1282984A CN 1282984 A CN1282984 A CN 1282984A CN 99111040 A CN99111040 A CN 99111040A CN 99111040 A CN99111040 A CN 99111040A CN 1282984 A CN1282984 A CN 1282984A
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- blue light
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- gallium nitride
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Abstract
A blue light LED using sapphire as substrate is prepared through such steps as etching at least one channel in sapphire substrate, generating gallium nitride film layer on both surfaces of substrate to make two film layers in contact with each other in said channel, and preparing positive and negative electrodes respectively at bottom layer of lower gallium nitride film and at top of LED crystal layer on substrate. Its advantages are small crystal grain action area and simplified subsequent steps to improve quality of products.
Description
The present invention relates to a kind of blue light-emitting diode and preparation method thereof, especially refer to that a kind of is the blue light-emitting diode of substrate material with the sapphire, it mainly is to offer at least one passage to pass through pipeline for electric current in sapphire substrate, and be formed with the close gallium nitride film layer of a thickness respectively the two-layer up and down of substrate, and be the vertical type blue light-emitting diode that thickness and active area all can significantly dwindle.
Light-emitting diode (LED; Light-Emitting Diode) develops so far since the fifties, since have the life-span long, volume is little, caloric value is low, power consumption is little, reaction speed is fast and unisexuality light emitting characteristics and advantage, so between short decades, light-emitting diode has been applied in various daily life products and the instrument and equipment, so all can find a large amount of use evidences of light-emitting diode in computer peripheral, clock display, billboard, traffic signal light, communications industry or the consumption electronic product, and extensively having to of this product range of application is startling.Especially work as blue light-emitting diode and ask city Hou, red, green, blue three coloured light all successively are developed and make successfully, and the complete basic structure of one-tenth one full colorization capable of being combined is not only more apparent changeable for utilization on color, replace on traditional white heat lighting source even be applied in, also allow the people in high spirits.
At present in the making of blue light-emitting diode, mainly can be divided into sapphire substrate (Sapphire) or be two big main shafts with silicon carbide substrate (SiC), but since on the physical properties such as the brightness of sapphire substrate, contrast or on the electrical property such as conductance all than silicon carbide substrate come outstanding, its expectability and future development also just are relatively higher than silicon carbide substrate certainly.
See also shown in Figure 1 present use with the blue light-emitting diode structure cutaway view of sapphire as substrate; On sapphire substrate 10, form a gallium nitride film layer (GaN) 12, sputter or evaporation one have the p-n interface and can launch light-emitting diode (LED) epitaxial layer 14 of blue-light source on gallium nitride film layer 12 again, because sapphire substrate 10 is an insulator, so can only be chosen on the top layer of LED epitaxial layer 14 and plate isoplanar first electrode (front electrode) 16 and second electrode (negative electrode) 18 more individually, and become the plane formula light-emitting diode.
But the sapphire substrate that uses has problem and the difficulty place of himself now:
1) since 10 of sapphire substrates as an insulator material, do not have conductive characteristic, so the positive and negative electrode 16,18 of its light-emitting diode must be plated on the same plane, so not only active area causes its light-emitting diodes pipe volume to be difficult to dwindle greatly, can't effectively reach the compact design object of product;
2) because 10 of sapphire substrates cause electrostatic interaction easily as an insulator material, the fraction defective when relatively also just causing production easily when making;
3) (thickness is H owing to the GaN thin layer 12 on the sapphire substrate 10
11) when the annealing cooling, cause that easily it acts on the stress inequality of substrate, and cause breaking of sapphire substrate 10, increase the trouble on the manufacture process on foot, so its substrate thickness H
1Can not be less than 280 microns (um).Generally when producing in batches, substrate thickness H
1All roughly be higher than 300 microns, and H
11Then be about 3～4 microns, so its H
1With H
11Thickness proportion be about 100: 1, the substrate of high thickness like this will run into great difficulty when cutting into the crystal grain program;
4) be the feasibility of convenient follow-up diamond cutting or laser cutting, so after light-emitting diode completes, it is about more than 200 microns also need as to grind its sapphire substrate 10 with high rigidity materials such as diamonds, not only causes cost to rise, and also increases the trouble on the manufacture process on foot.
Therefore, how a kind of novel solution and light-emitting diode to be proposed at the problems referred to above, not only allowing with the sapphire is the light-emitting diode that the blue light-emitting diode of substrate can become vertical type, can significantly reduce the thickness size of sapphire substrate again, except save the cost expenditure, also can improve its product fine rate and simplification manufacture process relatively, be that numerous practitioners eagerly look forward to for a long time always.
It is the blue light-emitting diode and preparation method thereof of substrate with the sapphire that main purpose of the present invention provides a kind of, on sapphire substrate, offer at least one passage, providing up and down, the electric current between two-layer positive and negative electrode passes through pipeline, so can become a vertical type photodiode crystal grain, use and dwindle its active area effect.
It is the blue light-emitting diode and preparation method thereof of substrate with the sapphire that secondary objective of the present invention provides a kind of, form the identical gallium nitride film layer of a thickness respectively in sapphire levels, and can be that its when cooling annealing formed stress repeals by implication, therefore its required substrate thickness can significantly be reduced to 150 microns, even below hundred microns, not only can prevent may breaking of sapphire substrate, also can save baseplate material, and simplify it relatively and grind the process steps of substrate afterwards.
It is the blue light-emitting diode and preparation method thereof of substrate with the sapphire that another purpose of the present invention provides a kind of, owing to have a passage to pass through between sapphire substrate, so formed static drawback can be eliminated and significantly improves its product fine rate between manufacturing process by electric current.
Of the present invention is that the blue light-emitting diode of substrate is achieved in that it is mainly constructed and includes with the sapphire: one has light-emitting diode (LED) epitaxial layer that blue light can be launched in a p-n interface; One is formed at the gallium nitride film layer (GaN) of this LED epitaxial layer bottom; One is formed at the sapphire substrate of this gallium nitride film layer bottom, offers the passage that at least one can run through the substrate both sides in this sapphire substrate, and has the gallium nitride film of part in passage; One is formed at first electrode of this LED epitaxial layer top layer; And one be formed at the conductive layer of this sapphire substrate bottom, and have the conductive layer material of part will be present in the passage of sapphire substrate, and sow film and contact with the nitrogenize in being present in this passage, and this conductive layer also can be as the comparative electrode of first electrode.
Wherein this conductive layer can be made by a nonmetal conductive material.
Wherein the thickness of this gallium nitride film layer is close with this conductive layer.
Wherein this conductive layer also can be a gallium nitride film layer.
Wherein bilevel gallium nitride film layer thickness is all identical.
Wherein this passage can have gradient.
Wherein this passage can be a linear state.
Wherein the thickness of this sapphire substrate is greater than 0 micron but be not more than 150 microns (um).
Wherein this first electrode can be a transparency electrode.
Still can be provided with second electrode that is formed at this conductive layer bottom, take this and to form current path via the passage of sapphire substrate and between first electrode.
Among the present invention be that the manufacture method of the blue light-emitting diode of substrate is achieved in that and includes the following step at least with the sapphire:
1) on a sapphire substrate, offers the passage that at least one runs through the substrate both sides;
2) top layer at sapphire substrate forms a gallium nitride film layer, and this gallium nitride film material is present in the segment space of passage;
3) form a conductive layer at the sapphire substrate bottom, and make this conductive material be present in the segment space of passage, and contact with gallium nitride film material in being present in passage;
4) form a LED epitaxial layer with p-n interface at the top layer of gallium nitride film layer; And
5) plate one first electrode at LED epitaxial layer top layer.
Wherein the passage of being offered in step (1) has a gradient.
Wherein in step (2), the gallium nitride film layer is formed on the top layer of sapphire substrate with organic metal gas phase brilliant method of heap of stone.
Wherein formed conductive layer is to select for use a nonmetal conductive material to make in step (3).
Wherein the conductive layer thickness of formation is akin in gallium nitride layer that step (2) forms and step (3).
Wherein formed conductive layer can select for use the gallium nitride material to make in step (3).
Wherein the gallium nitride layer thickness that forms respectively in step (2) and step (3) is identical.
Wherein in the step (1) selected process for sapphire-based plate thickness greater than 0 micron but be not more than 150 microns.
Wherein first electrode that forms in the step (5) can be a transparent material and makes.
Still can include a step (6): form corresponding second electrode of one and first electrode at the conductive layer bottom.
The present invention relates to a kind of blue light-emitting diode and preparation method thereof, particularly a kind of is the blue light-emitting diode of substrate with the sapphire, mainly be that erosion is provided with at least one passage in sapphire substrate, pass through pipeline for electric current, and at the up and down two-layer close gallium nitride film layer of a thickness that is formed with respectively of substrate, and allowing up and down, two-layer gallium nitride material is contacted with in the substrate channel, and just, negative electrode then can be formed at lower floor's gallium nitride film bottom individually and be positioned at the top layer of light-emitting diode epitaxial layer on the substrate, because setting up of this passage and can be just, provide one can allow the pipeline of electric current between negative electrode by substrate, so can become a vertically standing LED crystal grain, not only can significantly dwindle the crystal grain active area by this, and can simplify follow-up grinding substrate program and improve the product fine rate.
Be equipped with preferred embodiment and accompanying drawing below, architectural feature of the present invention and effect described:
Fig. 1 be use now with the blue light-emitting diode structure cutaway view of sapphire as substrate;
Fig. 2 is the preferred embodiment organigram of the present invention when making sapphire substrate;
Fig. 3 to Fig. 7 is each process steps structure cutaway view of blue light-emitting diode of the present invention;
Fig. 8 is another embodiment of the present invention organigram.
At first, see also Fig. 2, it is the preferred embodiment organigram of the present invention when making sapphire substrate; As previously mentioned, can form a no small stress during in the annealing cooling and act on the sapphire substrate now at the gallium nitride film that forms on the sapphire substrate, cause the fracture breakage of substrate easily, therefore have at present improve its anti-stress and prevent that the sapphire substrate fracture is damaged with the thickness that increases sapphire substrate.And in the present invention, when preparing sapphire substrate 20, can descend both sides to form thickness (H respectively thereon
3, H
4) and active area is approximate or identical gallium nitride (GaN) thin layer 222,224, so can be when the annealing cooling, though still can produce no small stress to this sapphire substrate 20, but because the stress on both sides will be repealed by implication up and down, so can not cause infringement, so the thickness (H of sapphire substrate 20 to sapphire substrate 20
2) also just need not to use so high.According to the experimental result gained, its used thickness can be not more than 150 microns (um), even uses to below 100 microns, therefore not only with regard on material use amount or the grinding substrate manufacture process afterwards, all can obtain greatest effect.
Moreover, see also Fig. 3 to Fig. 7, be each process steps structure cutaway view of blue light-emitting diode of the present invention; As shown in the figure, the main making step of the present invention includes:
Step 1: select a thickness to be not more than 100 microns sapphire substrate 30 (Sapphire), and utilize chemical etching or light shield stamp mode to offer the passage 31 that at least one runs through substrate 30 and has gradient betwixt, as shown in Figure 3;
Step 2: the top layer at sapphire substrate 30 forms one deck gallium nitride film layer 322 with organic metal gas phase brilliant method crystal types of heap of stone such as (MOVPE) of heap of stone, and the part material of this gallium nitride film 322 is present in the space of passage 31, as shown in Figure 4;
Step 3: the methods such as crystalline substance or sputter of building in sapphire substrate 30 bottom utilizations are to form a conductive layer 326, this conductive layer 326 can be made by a nonmetal conductive material, and these conductive layer 326 materials also are present in the segment space of passage 31, and interconnect with gallium nitride film 322 materials of preexist in passage 31, because 322 of gallium nitride films are as conductive material, so connection like this will form a complete conductive path, as shown in Figure 5;
Step 4: have the p-n interface and can launch the LED epitaxial layer 34 of blue-light source to form one with sputter or evaporation mode at the top layer of gallium nitride film layer 322, also can be the n-p interface certainly, shown in the number of scraping, as shown in Figure 6; And
Step 5: relative first electrode 36 and second electrode 38 on LED epitaxial layer 34 top layers and conductive layer 326 plated underlayers respectively so can form the LED crystal particle material of a vertical type, as shown in Figure 7.
Because, LED epitaxial layer 34, gallium nitride film layer 322, and conductive layer 326 be all the conductivity material, so 36,38 at two electrodes can provide a complete current channel by quoting of said elements and passage 31, shown in dotted line.Therefore the blue LED crystal grain of this vertical type can be crowned with success after cutting apart afterwards.Because positive and negative two electrodes 36,38 are positioned on the Different Plane, also just dwindle the active area in its LED epitaxial layer 34 fronts relatively, not only can save material and use, also can meet the short and small frivolous target of product.
At last, see also another embodiment of the present invention organigram shown in Figure 8.As shown in the figure, be in conjunction with disclosed technology among Fig. 2 in this embodiment, so the nonmetal conductive material of its conductive layer 326 can be selected the material identical with gallium nitride film layer 322 for use, and its bilevel thickness (H
3, H
4) be all approximate, even identical, not only can offset the stress that gallium nitride film layer 322,324 is produced by this when the annealing cooling, to safeguard not being destroyed of sapphire substrate 30, and it is the used thickness that can significantly reduce sapphire substrate 30, even also comparatively convenient in handling of goods and materials.
In addition, the passage 31 of mentioning in the previous steps 1 with gradient, it mainly is in order to form the convenience of gallium nitride film layer 322 and conductive layer 326 in step 2 and the step 3, to guarantee its contact really in passage 31.If but manufacture process convenient, also can offer the passage 31 of linear state in fact, be equally applicable to electric current of the present invention can between the electrode of positive and negative both sides, flow (shown in dotted line).Certainly, live the consideration that first electrode 36 on LED epitaxial layer 34 is launched for luminosity, also can select for use transparent material to make, and form transparency electrode.Again because conductive layer 326 or gallium nitride film layer 324 itself be conductive material and make, so second electrode 38 also can be replaced by conductive layer 326 or gallium nitride film layer 324 not in setting up.
In sum, the present invention is relevant a kind of blue light-emitting diode and preparation method thereof, especially refer to that a kind of is the blue light-emitting diode of substrate material with the sapphire, it mainly is to offer at least one passage to pass through pipeline for electric current in sapphire substrate, and be formed with the identical gallium nitride film layer of a thickness respectively the two-layer up and down of substrate, and be the vertical type blue light-emitting diode that thickness and active area all can significantly dwindle.
The above, it only is a preferred embodiment of the present invention, be not to be used for limiting scope of the invention process, for example can between LED epitaxial layer and gallium nitride film layer, add some impurity layers, as phosphorus indium gallium aluminium layer, or on other thin layer, increase other as SiC, AlN, SiO2, InGaN, SnO2, AlInGaP layer etc., every equalization of doing according to the described shape of the present patent application claim, structure, feature and spirit changes and modifies, and all should be included in the claim scope of the present invention.
Claims (20)
1, a kind of is the blue light-emitting diode of substrate with the sapphire, it is characterized in that: it is mainly constructed and includes: one has light-emitting diode (LED) epitaxial layer that blue light can be launched in a p-n interface; One is formed at the gallium nitride film layer (GaN) of this LED epitaxial layer bottom; One is formed at the sapphire substrate of this gallium nitride film layer bottom, offers the passage that at least one can run through the substrate both sides in this sapphire substrate, and has the gallium nitride film of part in passage; One is formed at first electrode of this LED epitaxial layer top layer; And one be formed at the conductive layer of this sapphire substrate bottom, and have the conductive layer material of part will be present in the passage of sapphire substrate, and sow film and contact with the nitrogenize in being present in this passage, and this conductive layer also can be as the comparative electrode of first electrode.
2, blue light-emitting diode as claimed in claim 1 is characterized in that: wherein this conductive layer can be made by a nonmetal conductive material.
3, blue light-emitting diode as claimed in claim 1 is characterized in that: wherein the thickness of this gallium nitride film layer is close with this conductive layer.
4, blue light-emitting diode as claimed in claim 1 is characterized in that: an also gallium nitride film layer of this conductive layer wherein.
5, blue light-emitting diode as claimed in claim 4 is characterized in that: wherein bilevel gallium nitride film layer thickness is all identical.
6, blue light-emitting diode as claimed in claim 1 is characterized in that: wherein this passage can have gradient.
7, blue light-emitting diode as claimed in claim 1 is characterized in that: wherein this passage can be a linear state.
8, blue light-emitting diode as claimed in claim 1 is characterized in that: wherein the thickness of this sapphire substrate is greater than 0 micron but be not more than 150 microns.
9, blue light-emitting diode as claimed in claim 1 is characterized in that: wherein this first electrode can be a transparency electrode.
10 blue light-emitting diodes as claimed in claim 1 is characterized in that: still can be provided with second electrode that is formed at this conductive layer bottom, take this and can form current path via the passage of sapphire substrate and between first electrode.
11, a kind of is the blue light-emitting diode manufacture method of substrate with the sapphire, it is characterized in that: include the following step at least:
1) on a sapphire substrate, offers the passage that at least one runs through the substrate both sides;
2) top layer at sapphire substrate forms a gallium nitride film layer, and this gallium nitride film material is present in the segment space of passage;
3) form a conductive layer at the sapphire substrate bottom, and make this conductive material be present in the segment space of passage, and contact with gallium nitride film material in being present in passage;
4) form a LED epitaxial layer with p-n interface at the top layer of gallium nitride film layer; And
5) plate one first electrode at LED epitaxial layer top layer.
12, the manufacture method of blue light-emitting diode as claimed in claim 11 is characterized in that: wherein the passage of being offered in step (1) has a gradient.
13, the manufacture method of blue light-emitting diode as claimed in claim 11 is characterized in that: wherein with organic metal gas phase brilliant method of heap of stone the gallium nitride film layer is formed on the top layer of sapphire substrate in step (2).
14, the manufacture method of blue light-emitting diode as claimed in claim 11 is characterized in that: wherein formed conductive layer is to select for use a nonmetal conductive material to make in step (3).
15, the manufacture method of blue light emitting utmost point pipe as claimed in claim 11 is characterized in that: wherein the conductive layer thickness of formation is akin in gallium nitride layer that step (2) forms and step (3).
16, the manufacture method of blue light-emitting diode as claimed in claim 11 is characterized in that: wherein formed conductive layer can select for use the gallium nitride material to make in step (3).
17, the manufacture method of blue light-emitting diode as claimed in claim 16 is characterized in that: wherein the gallium nitride layer thickness that forms respectively in step (2) and step (3) is identical.
18, the manufacture method of blue light-emitting diode as claimed in claim 11 is characterized in that: wherein in the step (1) selected process for sapphire-based plate thickness greater than 0 micron but be not more than 150 microns.
19, the manufacture method of blue light-emitting diode as claimed in claim 11 is characterized in that: wherein first electrode that forms in the step (5) can be a transparent material and makes.
20, the manufacture method of blue light-emitting diode as claimed in claim 11 is characterized in that: still can include a step (6): form corresponding second electrode of one and first electrode at the conductive layer bottom.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN99111040A CN1123937C (en) | 1999-07-28 | 1999-07-28 | Blue-light LED using sapphire as substrate and its making technology |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN99111040A CN1123937C (en) | 1999-07-28 | 1999-07-28 | Blue-light LED using sapphire as substrate and its making technology |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1282984A true CN1282984A (en) | 2001-02-07 |
| CN1123937C CN1123937C (en) | 2003-10-08 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN99111040A Expired - Fee Related CN1123937C (en) | 1999-07-28 | 1999-07-28 | Blue-light LED using sapphire as substrate and its making technology |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100405618C (en) * | 2002-05-31 | 2008-07-23 | 株式会社光波 | Laminous element and its producing method |
| CN102161502A (en) * | 2011-04-21 | 2011-08-24 | 华中科技大学 | CVD process for synthesizing bismuth-assisted gallium oxide nano rings |
| CN112233969A (en) * | 2020-10-21 | 2021-01-15 | 国网山东省电力公司电力科学研究院 | Method for preparing low-stress GaN film |
-
1999
- 1999-07-28 CN CN99111040A patent/CN1123937C/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100405618C (en) * | 2002-05-31 | 2008-07-23 | 株式会社光波 | Laminous element and its producing method |
| CN101320780B (en) * | 2002-05-31 | 2010-06-16 | 株式会社光波 | Light emitting element |
| CN102161502A (en) * | 2011-04-21 | 2011-08-24 | 华中科技大学 | CVD process for synthesizing bismuth-assisted gallium oxide nano rings |
| CN102161502B (en) * | 2011-04-21 | 2012-10-10 | 华中科技大学 | CVD process for synthesizing bismuth-assisted gallium oxide nano rings |
| CN112233969A (en) * | 2020-10-21 | 2021-01-15 | 国网山东省电力公司电力科学研究院 | Method for preparing low-stress GaN film |
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| Publication number | Publication date |
|---|---|
| CN1123937C (en) | 2003-10-08 |
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