201145560 六、發明說明： 【發明所屬之技術領域】 [0001] 本發明係有關發光二極體結構，尤其關於具備布拉 格薄膜與金屬層的發光二極體。 【先前技術】 [0002] 請參閱「圖1」所示，其為傳統藍光發光二極體的結 構，其為在一藍寶石基板1上依序成長一N型氮化鎵層2、 一活化層3與一 P型氮化鎵層4，並於該N型氮化鎵層2與該 P型氮化鎵層4上分別鍍上一 N型電極5與一 P型電極6後， 〇 即形成發光二極體結構。 [0003] 此傳統藍光發光二極體結構，其所發出的光為不定 方向，因此大半的光會從藍寶石基板1處散出，而無法作 為顯示光源之用，進而降低了光源的淬取效率。 [0004] 因此習知為增加光源的淬取效率，必須搭配封裝模 組中的反射材料才能將射向底部的光由正南或側向反射 出去，然即使鍍有高反射的金屬於發光二極體晶粒的背 〇 面，因金屬本身有吸光的特性，會降低底部反射的效率 ，仍無法有效增加光源的淬取效率。 【發明内容】 [0005] 爰是，本發明的主要目的在於揭露一種具高反射率 的發光二極體結構，以增加發光亮度。 [0006] 基於上述目的，本發明揭露一種具備布拉格薄膜與 金屬層的發光二極體，其包含一藍寶石基板、一布拉格 薄膜、一發光層與一金屬層，其中發光層成長於該藍寶 099117560 表單編號A0101 第3頁/共15頁 0992031194-0 201145560 [0007] [0008] [0009] [0010] 099117560 石基板上，該布拉格薄膜設於該藍寶石基板遠離該發光 ' 層的一側，且該布拉格薄膜具有至少二薄膜層，該至少 二薄膜層為兩種不同折射率的材料交互疊置，而該金屬 層設於該布拉格薄膜上。 據此，藉由形成於該藍寶石基板之下的布拉格薄膜 與金屬層，具極高的反射率，可提供作為高反射率的區 域，以反射該發光層所產生的光，讓朝下射出的光再一 次反射由表面或側邊出光，以大幅提昇光的淬取效率。 【實施方式】 茲有關本發明的詳細内容及技術說明，現以實施例 來作進一步說明，但應瞭解的是，該等實施例僅為例示 說明之用，而不應被解釋為本發明實施之限制。 請參閱「圖2」所示，本發明為一種具備布拉格薄膜 與金屬層的發光二極體，其包含一藍寶石基板10、一布 拉格薄膜20、一發光層30與一金屬層40，該發光層30成 長於該藍寶石基板10上，且該布拉格薄膜20設於該藍寶 石基板10遠離該發光層30的一側，並該金屬層40設於該 布拉格薄膜20上。 又該發光層30為包含一 N型半導體層31、一活化層 32與一 P型半導體層33，其中該N型半導體層31與該P型 半導體層33上分別鍍有一 N型電極34與一 P型電極35，並 該N型半導體層31與該P型半導體層33為選自氮化鎵 (GaN)、氮化銦鎵（InGaN)、氮化鋁銦鎵（AlInGaN)、磷 化鎵（GaP) '鱗化鋁銦鎵（AlInGaP)、磷化鋁銦（AllnP) 與砷化鋁鎵（AlGaAs)的任一種製成，而該活化層32為氮 表單編號A0101 第4頁/共15頁 0992031194-0 201145560 匕鎵（GaN)、氮化銦鎵（inGaN)、氮化鋁銦鎵（A1InGaN) 、磷化鎵（GaP)、磷化鋁銦鎵（A1InGap)、磷化鋁銦 (A1InP)與砷化鋁鎵（AlGaAs)中任一種之量子井 (Quantum Well)搭配阻擋層（Barrie〇的週期性結構。 [0011]201145560 VI. Description of the Invention: [Technical Field of the Invention] [0001] The present invention relates to a light-emitting diode structure, and more particularly to a light-emitting diode having a Bragg film and a metal layer. [Prior Art] [0002] Please refer to FIG. 1 , which is a structure of a conventional blue light emitting diode, which sequentially grows an N-type gallium nitride layer 2 and an active layer on a sapphire substrate 1 . 3 and a P-type gallium nitride layer 4, and an N-type electrode 5 and a P-type electrode 6 are respectively plated on the N-type gallium nitride layer 2 and the P-type gallium nitride layer 4, respectively, Light-emitting diode structure. [0003] The conventional blue light emitting diode structure emits light in an indefinite direction, so most of the light is emitted from the sapphire substrate 1 and cannot be used as a display light source, thereby reducing the extraction efficiency of the light source. . [0004] Therefore, in order to increase the extraction efficiency of the light source, it is necessary to use the reflective material in the package module to reflect the light directed to the bottom from the south or the lateral direction, even if the metal with high reflection is coated with the light The back surface of the polar crystal grains, because of the light absorption characteristics of the metal itself, reduces the efficiency of the bottom reflection, and still cannot effectively increase the extraction efficiency of the light source. SUMMARY OF THE INVENTION [0005] The main purpose of the present invention is to disclose a light-emitting diode structure having high reflectivity to increase the luminance of light. [0006] Based on the above objective, the present invention discloses a light-emitting diode having a Bragg film and a metal layer, comprising a sapphire substrate, a Bragg film, a light-emitting layer and a metal layer, wherein the light-emitting layer is grown on the sapphire 099117560 Form No. A0101 Page 3 / 15 pages 0992031194-0 201145560 [0007] [0009] [0010] 099117560 On a stone substrate, the Bragg film is disposed on a side of the sapphire substrate away from the luminescent layer, and The Bragg film has at least two film layers which are alternately stacked with two different refractive index materials, and the metal layer is disposed on the Bragg film. Accordingly, the Bragg film and the metal layer formed under the sapphire substrate have an extremely high reflectance, and a region having high reflectance can be provided to reflect the light generated by the luminescent layer to be emitted downward. The light is again reflected by the surface or the side to greatly enhance the light extraction efficiency. The detailed description of the present invention and the technical description thereof will be further described by way of examples, but it should be understood that these embodiments are for illustrative purposes only and should not be construed as The limit. Referring to FIG. 2, the present invention is a light-emitting diode having a Bragg film and a metal layer, comprising a sapphire substrate 10, a Bragg film 20, a light-emitting layer 30 and a metal layer 40. 30 is grown on the sapphire substrate 10, and the Bragg film 20 is disposed on a side of the sapphire substrate 10 away from the luminescent layer 30, and the metal layer 40 is disposed on the Bragg film 20. The light-emitting layer 30 further includes an N-type semiconductor layer 31, an active layer 32 and a P-type semiconductor layer 33. The N-type semiconductor layer 31 and the P-type semiconductor layer 33 are respectively plated with an N-type electrode 34 and a a P-type electrode 35, and the N-type semiconductor layer 31 and the P-type semiconductor layer 33 are selected from the group consisting of gallium nitride (GaN), indium gallium nitride (InGaN), aluminum indium gallium nitride (AlInGaN), and gallium phosphide ( GaP) 'Symmetric aluminum indium gallium (AlInGaP), aluminum indium phosphide (AllnP) and aluminum gallium arsenide (AlGaAs), and the active layer 32 is nitrogen form number A0101 Page 4 of 15 0992031194-0 201145560 GaN, InGaN, A1InGaN, GaP, A1InGap, A1InP A quantum well with any one of aluminum gallium arsenide (AlGaAs) is used with a barrier layer (Barrie〇 periodic structure. [0011]
G 〇 [0012] [0013] 099117560 "月一併參閱「圖3」所示，該布拉格薄膜2〇具有至少 二薄膜層2卜22 ’該至少二薄膜層2卜22為兩種不同折 射率的材料交互疊置，亦即該布拉格薄膜2〇為複數多層 膜結構，此處為了表示的方便，僅繪製四個來代表。又 該布拉格薄膜20中，折射率較高的薄膜層21可以選自折 射率（Refraction rnciex)大於17之高折射率光學薄膜 材料（如二氧化鈦（Ti〇2)、多氮化矽（s:iNxi、五氧化二 组（Ta2〇5)、氧化鍅（Zr2〇3))的任_種，折;射率較低的 薄膜層22可以選自折射率（Refracti〇n Index)低於t 7 之低折射率光學薄膜材料（如二氧化矽（Si〇 )、氟化鎂 2 (MgFp的任一種。又該金屬層4〇可以逄自銀與鋁的任一 種製成。 請再參閱「圖4」所示，本發明於藍寶石基板1〇之下 ，設定該布拉格薄膜20與該金屬層4〇，且該布拉格薄膜 20交互排列兩種不同折射率的材料，因而可提供作為高 反射率的區域，可反射該發光層3〇所產生的光，讓朝下 射出的光再一次反射由表面或側邊出光，以提昇光淬取 效率。 請再參閱「圖5」與「圖6」所示，本發明的布拉格 薄膜20可經優化而具優化的厚度與材料堆疊，其優化方 式為透過電腦模擬軟體以類似布拉格反射鏡的結構做優 表單編號A0101 第5頁/共15頁 0992031194-0 201145560 兩種不同材料之介電層交叉 化。傳統布拉格反射鏡是以 堆疊，其每種材料在相互堆疊的過程中之光學厚度是相 同的，可以稱其週期性堆疊交錯組合為—組布拉格反射 鏡。而具優化之布拉格薄膜20是以一組以上之布拉格反 射鏡所組合而成，此外具優化之各層光學厚度於每組布 拉格反射鏡是不相同的’在鍍完具優化布拉格薄膜20後 ，於最後一層鏡上铭或銀系列之金屬層40 ’以提供全角 度之高反射特性。 [0014] [0015] [0016] [0017] [0018] [0019] [0020] [0021] [0022] [0023] [0024] [0025] [0026] 而本發明的實施例，其優化後薄膜备層結構如下： 第一層（lst)Si〇2: λ/(4η); 第二層（2nd)Ti〇2: ;: 第三層（3rd)Si〇2: λ/(4η); 第四層（4th)Ti〇2:又八411); 第五層（5th)Si〇2: 5λ/(4η>; 第六層（6th)Ti〇2: 3λΑ4η) ;、 第七層（7th)Si〇2: 2. 41 λ/(4η); 第八層（8th)Ti〇2: 1.2λ/(4η); 第九層（9th)Si〇2: 2·43λΑ4η); 第十層（10th)Ti〇2: 〇·5；^(4η); 其中λ為入射光的波長、η為正整數。 如「圖5」所示，其光垂直元件由正上方射入，其中 099117560 表單編號Α0101 第6頁/共15頁 0992031194-0 201145560 [0027] Ο [0028] G [0029] [0030] [0031] [0032] [0033] [0034] 光反射率曲線5Α為傳統使用純鋁的曲線圖，光反射率曲 線5B為本發明使用該布拉格薄膜2〇與該金屬層4〇(使用鋁 )的曲線圖，光反射率曲線5C則為優化後的布拉格薄膜20 與該金屬層40(使用鋁）的曲線圖，由圖可知，使用布拉 格薄膜20的光反射率曲線5B、5C明顯高於傳統的光反射 率曲線5A，亦即可增加反射率而提昇光淬取效率。 而如「圖6」所示，光反射率曲線6A為460nm光波於 傳統使用純鋁於不同角度入射的曲線圖，光反射率曲線 6B則為使用該布拉格薄膜⑼與該金屬層4〇(使用鋁）的曲 線圖’光反射率曲線6C則為優化後的布拉格薄膜20與該 金屬層40(使用鋁）的曲線圖，如圖所示，使用優化後的 布拉格薄膜2〇其在不同的入射角皆具良好的反射率，因 此可大幅的提高光淬取效率。 惟上述僅為本發明之較佳實施例而已，並非用來限 疋本發明實施之範面。即凡依本發明_攀夸利範圍所做 的均等變化與修飾，皆為本發明專利範圍所涵蓋。 ' \ .：：：： 【圖式簡單說明】 圖1，為習知發光二極體結構斷面圖。 圖2，為本發明發光二極體結構斷面圖。 圖3，為本發明布拉格薄膜斷面圖。 圖4 ’為本發明發光示意圖。 圖5，為本發明波長-反射率曲線圖。 圖6，為本發明入射角-反射率曲線圖。 099117560 表軍蝙號A0101 第7頁/共15頁 0992031194-0 201145560 【主要元件符號說明】 [0035] 習知 1 :藍寶石基板 2 : N型氮化鎵層 3 :活化層 4 : P型氮化鎵層 5 : N型電極 6 : P型電極 本發明 5A、5B、5C :光反射率曲線 6A、6B、6C :光反射率曲線 10 :藍寶石基板 20 :布拉格薄膜 21、22 :薄膜層 30 :發光層 31 : N型半導體層 32 :活化層 33 : P型半導體層 34 : N型電極 35 : P型電極 40 :金屬層 099117560 表單編號A0101 第8頁/共15頁 0992031194-0G 〇 [0012] [0013] [0013] 099117560 "Monthly, as shown in "Figure 3", the Bragg film 2 〇 has at least two film layers 2 22 ' at least two film layers 2 22 for two different refractive indices The materials are alternately stacked, that is, the Bragg film 2 is a plurality of multilayer film structures, and only four are represented here for convenience of representation. Further, in the Bragg film 20, the film layer 21 having a higher refractive index may be selected from a high refractive index optical film material having a refractive index greater than 17 (such as titanium dioxide (Ti〇2), polynitridium (s:iNxi). Any of the pentoxide groups (Ta2〇5) and yttrium oxide (Zr2〇3), the film layer 22 having a lower incidence can be selected from a refractive index (Refracti〇n Index) lower than t7. A low-refractive-index optical film material (such as cerium oxide (Si〇) or magnesium fluoride 2 (any one of MgFp. The metal layer 4 can be made of any of silver and aluminum. Please refer to Figure 4 again) The present invention is characterized in that the Bragg film 20 and the metal layer 4 are disposed under the sapphire substrate, and the Bragg film 20 is alternately arranged with two materials of different refractive indices, thereby providing a region with high reflectance. The light generated by the light-emitting layer 3 is reflected, and the light emitted downward is again reflected by the surface or the side to enhance the light extraction efficiency. Please refer to FIG. 5 and FIG. 6 respectively. The inventive Bragg film 20 can be optimized for optimized thickness and material stacking The optimization method is to make the form of the structure similar to the Bragg mirror through the computer simulation software. A0101 Page 5 / 15 pages 0992031194-0 201145560 The dielectric layers of two different materials are cross-cored. The traditional Bragg mirrors are stacked. The optical thickness of each of the materials is the same when stacked on each other, and can be said to be periodically stacked and interleaved into a group of Bragg mirrors. The optimized Bragg film 20 is a combination of more than one set of Bragg mirrors. In addition, the optimized optical thickness of each layer is different for each group of Bragg mirrors. 'After plating the optimized Bragg film 20, the last layer of mirror or silver metal layer 40' provides full angle. [0014] [0015] [0020] [0020] [0020] [0024] [0025] [0025] [0026] While embodiments of the present invention, The optimized film preparation structure is as follows: first layer (lst) Si〇2: λ/(4η); second layer (2nd) Ti〇2: ;: third layer (3rd)Si〇2: λ/( 4η); fourth layer (4th) Ti〇2: eight 411); fifth layer (5th) Si〇2: 5λ/(4 >; sixth layer (6th) Ti〇2: 3λΑ4η) ;, seventh layer (7th)Si〇2: 2. 41 λ/(4η); eighth layer (8th) Ti〇2: 1.2λ/( 4η); ninth layer (9th)Si〇2: 2·43λΑ4η); tenth layer (10th) Ti〇2: 〇·5;^(4η); where λ is the wavelength of incident light, and η is a positive integer. As shown in Fig. 5, the light vertical elements are incident from directly above, wherein 099117560 Form No. 1010101 Page 6 / Total 15 Page 0992031194-0 201145560 [0027] Ο [0028] G [0029] [0030] [0031 [0034] [0034] The light reflectance curve 5 Α is a conventionally used graph of pure aluminum, and the light reflectance curve 5B is a curve of the present invention using the Bragg film 2 〇 and the metal layer 4 〇 (using aluminum) The light reflectance curve 5C is a graph of the optimized Bragg film 20 and the metal layer 40 (using aluminum). As can be seen from the figure, the light reflectance curves 5B and 5C using the Bragg film 20 are significantly higher than the conventional light. The reflectance curve 5A also increases the reflectivity and improves the light extraction efficiency. As shown in Fig. 6, the light reflectance curve 6A is a graph of the 460 nm light wave incident on the conventional use of pure aluminum at different angles, and the light reflectance curve 6B is the use of the Bragg film (9) and the metal layer 4 (using The graph of the aluminum's light reflectance curve 6C is a graph of the optimized Bragg film 20 and the metal layer 40 (using aluminum), as shown, using the optimized Bragg film 2 at different incidences. The corners have good reflectivity, which greatly improves the light extraction efficiency. The above are only the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. That is, the equal changes and modifications made by the scope of the invention according to the invention are covered by the scope of the invention. ' \ .:::: [Simple description of the drawing] Figure 1 is a cross-sectional view of a conventional light-emitting diode structure. 2 is a cross-sectional view showing the structure of a light-emitting diode of the present invention. Figure 3 is a cross-sectional view of a Bragg film of the present invention. Figure 4' is a schematic view of the illumination of the present invention. Fig. 5 is a graph showing the wavelength-reflectance of the present invention. Fig. 6 is a graph showing incident angle-reflectance of the present invention. 099117560 Table bat No. A0101 Page 7 of 15 0992031194-0 201145560 [Main component symbol description] [0035] Convention 1: Sapphire substrate 2: N-type gallium nitride layer 3: Activation layer 4: P-type nitridation Gallium layer 5: N-type electrode 6: P-type electrode 5A, 5B, 5C of the present invention: Light reflectance curve 6A, 6B, 6C: Light reflectance curve 10: Sapphire substrate 20: Bragg film 21, 22: Film layer 30: Light-emitting layer 31: N-type semiconductor layer 32: Activation layer 33: P-type semiconductor layer 34: N-type electrode 35: P-type electrode 40: Metal layer 099117560 Form No. A0101 Page 8 of 15 0992031194-0