1253771 17098twf.doc/r 九、發明說明： 【發明所屬之技術領域】 本發明是有關於—種發光元件，且特別是有關於一種 發光二極體結構。 【先前技術】 由於發光二極體與傳統燈泡比較具有絕對的優勢，例 如體積小、壽命長、低電壓/電流驅動、不易破裂、發光時 ^顯著之熱問題、不含水銀（沒有污染問題）、發光效率 ^ (省電）等特性’且近幾年來發光二極體的發光效率不 斷提升，因此發光二極體在某些領域已漸漸取代日光燈與 白，燈泡，例如需要高速反應的掃描器燈源、液晶顯示器 的$光源或前光源汽車的儀表板照明、交通號誌燈以及一 般的照明裝置等。 、、、而且，由於含氮之m-v族化合物為一寬頻帶能隙之材 料丄ΐ發光波長可以從紫外光一直含蓋至紅光，可說是幾 乎3盍整個可見光的波段。因此，利用含氮化鎵的化合物 半導體’如氮化鎵(GaN)、氮化鋁鎵(GaA1N)、氮化銦鎵 (GalnN)等的發光二極體元件已廣泛地應用在各種發光模 組中。 、 圖1繪不為習知發光二極體結構的剖面示意圖。請參 照圖1，發光二極體結構100主要是由基板11〇、η型摻雜 半V體層120、電極122、發光層no、ρ型摻雜半導體層 140，、歐姆接觸層150以及電極142所構成。其中，η型摻 雜半導體層120、發光層13〇、ρ型摻雜半導體層14〇、歐 5 1253771 17098twf.doc/r 姆接觸層150以及電極142是依序配置於基板11〇上，且 考X光層13二僅覆盍住部分的n型換雜半導體層⑽，而電 極122 ρ疋配置在未被發光層所覆蓋 體層120上。 7作干夺 ， 請繼續參照圖卜當η型摻雜半導體層12〇所提供的 電子與Ρ型摻雜半導體層14〇所提供的電洞在發光層 • 内再結合，並因而產生光線102之後，-部份之光線1〇2 # 會穿透歐姆接觸層150與基板110，而分別往發光二極體 結構100之上、下方出射。此外，另一部分的光線102則 會被基板110表面或電極142與ρ型摻雜半導體層14〇的 界面反射，而在η型摻雜半導體層12〇至ρ型摻雜半導體 層140之間橫向傳遞。此時，光線1〇2會有部分的能量被 η型摻雜半導體層120、ρ型摻雜半導體層14〇、電極122 或電極142所吸收，導致發光二極體結構1〇〇的外部量子 效率降低。 為解決上述問題，日本專利特開平u_274568號公報 鲁 疋藉由機械研磨及姓刻專製程，任意地粗化發光二極體結 , 構的基板表面，以使欲射入基板的光線被散射，進而提高 發光二極體結構的外部量子效率。 然而，任思地粗化基板表面實際上並無法有效地提高 發光二極體結構的外部量子效率。一方面是因為當基板表 面上的凹陷圖案或凸起圖案過大時，將會導致在此表面上 生長之η型摻雜半導體層的結晶性降低，因而降低此發光 二極體結構的内部量子效率，導致外部量子效率無法提 6 1253771 17098twf.doc/r 高。另一方面則是因為任意地粗化基板表面將導致橫向傳 遞之光能量更容易被此粗化表面所吸收，導致出射發光二 極體結構的光線衰減’因而無法達到足夠的外部量子效率。 【發明内容】 有鑑於此，本發明的目的就是在提供一種發光二極體 結構，其具有光子晶體之基板不但可以改善磊晶品質，還 可以減少沿基板表面傳遞的光線，以增加此發光二極體結 構的發光效率。 本發明提出一種發光二極體結構，包括基板、第一型 摻雜半導體層、發光層、第二型摻雜半導體層與第二電極。 其中，基板具有一表面以及多個位於表面上之圓柱狀光子 晶體(photonic crystal)。第一型摻雜半導體層是配置於基板 上以覆蓋這些光子晶體，發光層則是配置於部分之第一型 換雜半導體層上。第二型摻雜半導體廣與第二電極是依序 配置於發光層上，而第-電極則是配置於未覆蓋有發光層 的部分第一型摻雜半導體層上。 在本發明的較佳實施例中，上述之發光二極體結構例 如更包括一歐姆接觸層，其是配置於第二型摻雜半導體層 與第二電極之間。 曰 、曰在本發明的較佳實施例中，上述之光子晶體之直徑可 j是彼此不同或相同。而且，這钱子晶體例如是凸起圖 案及凹槽至少其中之一。 在本發明的較佳實補巾，上述之奸晶體例如是在 上述基板的表面上排列成mxn之矩陣，且m、η皆為正整 1253771 17098twf.doc/r 數0 在本發明的較佳實施例中’上述之光子晶體是排列成 多列奇數列與多列偶數列，且各偶數列之光子晶體是對應 於奇數列中相鄰之第一光子晶體間的間隔。而且，在一^ 施例中，奇數列之光子晶體的排列間距例如是與偶數列之 光子晶體的排列間距不同。此外，這些光子晶體的排列型 • 態也可以是各奇數列之光子晶體相互對齊，而第k列之偶 鲁數列的光子晶體是對應於奇數列與第k+丨列偶數列中相鄰 之光子晶體間的間隔。其中，k為正整數。 在本發明的較佳實施例中，上述之光子晶體例如是^ 上述基板的表面上排列成蜂巢狀。 、，本發明的較佳實施例中，上述之光子晶體例如有_ 部份是在上述基板的表面上排列成蜂巢狀，並環繞另一名 份的光子晶體。在一實施例中，排列成蜂巢狀之光子晶# 的直徑例如是大於其餘第二光子晶體的直徑。 曰曰&1253771 17098twf.doc/r IX. Description of the Invention: TECHNICAL FIELD The present invention relates to a light-emitting element, and more particularly to a light-emitting diode structure. [Prior Art] Since the light-emitting diode has absolute advantages compared with the conventional light bulb, for example, small volume, long life, low voltage/current driving, not easy to break, significant heat problem when emitting light, no mercury (no pollution problem) , luminous efficiency ^ (power saving) and other characteristics 'and in recent years, the luminous efficiency of the LED is increasing, so the LED has gradually replaced fluorescent lamps and white in some areas, such as scanners that require high-speed response Light source, liquid crystal display, light source or front light source car dashboard lighting, traffic lights, and general lighting. Moreover, since the nitrogen-containing m-v group compound is a broadband band gap material, the emission wavelength can be covered from ultraviolet light to red light, which can be said to be almost the entire visible light band. Therefore, a light-emitting diode element using a gallium nitride-containing compound semiconductor such as gallium nitride (GaN), aluminum gallium nitride (GaA1N), or indium gallium nitride (GalnN) has been widely used in various light-emitting modules. in. FIG. 1 is a schematic cross-sectional view showing a structure of a conventional light emitting diode. Referring to FIG. 1 , the LED structure 100 is mainly composed of a substrate 11 , an n-type doped V-body layer 120 , an electrode 122 , a light-emitting layer no, a p-type doped semiconductor layer 140 , an ohmic contact layer 150 , and an electrode 142 . Composition. The n-type doped semiconductor layer 120, the light-emitting layer 13A, the p-type doped semiconductor layer 14A, the ohmic 5 1253771 17098 twf.doc/r contact layer 150, and the electrode 142 are sequentially disposed on the substrate 11〇, and The X-ray layer 13 is only covered by a portion of the n-type semiconductor layer (10), and the electrode 122 is disposed on the body layer 120 not covered by the light-emitting layer. 7 for dry, please continue to refer to the electrons provided by the n-type doped semiconductor layer 12, and the holes provided by the germanium-doped semiconductor layer 14 are recombined in the light-emitting layer, and thus generate light 102. Thereafter, a portion of the light 1〇2 # penetrates the ohmic contact layer 150 and the substrate 110, and exits above and below the light emitting diode structure 100, respectively. In addition, another portion of the light ray 102 is reflected by the surface of the substrate 110 or the interface between the electrode 142 and the p-type doped semiconductor layer 14A, and laterally between the n-type doped semiconductor layer 12 〇 to the p-type doped semiconductor layer 140. transfer. At this time, part of the energy of the light 1 〇 2 is absorbed by the n-type doped semiconductor layer 120, the p-type doped semiconductor layer 14 〇, the electrode 122 or the electrode 142, resulting in an external quantum of the light-emitting diode structure 1 〇 Reduced efficiency. In order to solve the above problems, the Japanese Patent Laid-Open No. U_274568 discloses that the surface of the substrate of the light-emitting diode is arbitrarily roughened by mechanical grinding and the process of casting, so that the light to be incident into the substrate is scattered. Further, the external quantum efficiency of the light-emitting diode structure is improved. However, roughening the surface of the substrate virtually does not effectively improve the external quantum efficiency of the light-emitting diode structure. On the one hand, when the concave pattern or the convex pattern on the surface of the substrate is too large, the crystallinity of the n-type doped semiconductor layer grown on the surface is lowered, thereby reducing the internal quantum efficiency of the light-emitting diode structure. , resulting in external quantum efficiency can not be raised 6 1253771 17098twf.doc / r high. On the other hand, because arbitrarily roughening the surface of the substrate will cause the light energy transmitted laterally to be more easily absorbed by the roughened surface, resulting in attenuation of light exiting the structure of the light-emitting diode, thus failing to achieve sufficient external quantum efficiency. SUMMARY OF THE INVENTION In view of the above, the object of the present invention is to provide a light-emitting diode structure, the substrate having the photonic crystal can not only improve the epitaxial quality, but also reduce the light transmitted along the surface of the substrate to increase the light-emitting The luminous efficiency of the polar body structure. The invention provides a light emitting diode structure comprising a substrate, a first type doped semiconductor layer, a light emitting layer, a second type doped semiconductor layer and a second electrode. Wherein the substrate has a surface and a plurality of cylindrical photonic crystals on the surface. The first type doped semiconductor layer is disposed on the substrate to cover the photonic crystals, and the light emitting layer is disposed on a portion of the first type of the modified semiconductor layer. The second type doped semiconductor and the second electrode are sequentially disposed on the light emitting layer, and the first electrode is disposed on a portion of the first type doped semiconductor layer not covered with the light emitting layer. In a preferred embodiment of the present invention, the above-described light emitting diode structure further includes an ohmic contact layer disposed between the second type doped semiconductor layer and the second electrode.曰, 曰 In a preferred embodiment of the invention, the diameters of the photonic crystals described above may be different or identical to each other. Moreover, the crystal of the money is, for example, at least one of a convex pattern and a groove. In the preferred embodiment of the present invention, the above-mentioned rape crystals are, for example, arranged in a matrix of mxn on the surface of the substrate, and m and n are both positive 1253771 17098 twf.doc/r number 0. In the embodiment, the photonic crystals described above are arranged in a plurality of columns of odd-numbered columns and a plurality of columns of even-numbered columns, and the photonic crystals of the even-numbered columns correspond to intervals between adjacent first photonic crystals in the odd-numbered columns. Moreover, in an embodiment, the arrangement pitch of the odd-numbered photonic crystals is, for example, different from the arrangement pitch of the photonic crystals of the even-numbered columns. In addition, the arrangement of the photonic crystals may be such that the photonic crystals of the odd-numbered columns are aligned with each other, and the photonic crystals of the even-numbered columns of the k-th column correspond to photons adjacent to the odd-numbered columns and the even-numbered columns of the k-th column. The spacing between the crystals. Where k is a positive integer. In a preferred embodiment of the present invention, the photonic crystal described above is, for example, arranged in a honeycomb shape on the surface of the substrate. In a preferred embodiment of the present invention, the photonic crystal has, for example, a portion which is arranged in a honeycomb shape on the surface of the substrate and surrounds another photonic crystal. In one embodiment, the diameter of the photonic crystals # arranged in a honeycomb shape is, for example, greater than the diameter of the remaining second photonic crystals.曰曰&
在本發明的較佳實施例中，上述之基板例如是藍· 石、碳化矽、尖晶石或矽基板。 现1 在本發明的較佳實施例中，上述之光子晶體在垂直3 板之表面的方向上，其尺寸例如是介於G.2微米至3微^ 之間，而光子晶體的直徑例如是介於〇 25微米至5微米< 間。此外，相鄰之光子晶體的間距例如是介於g.5微^In a preferred embodiment of the invention, the substrate is, for example, a blue stone, a tantalum carbide, a spinel or a tantalum substrate. In a preferred embodiment of the present invention, the photonic crystal has a size of, for example, G. 2 μm to 3 μm in the direction of the surface of the vertical 3 plate, and the diameter of the photonic crystal is, for example, Between 25 microns and 5 microns < In addition, the spacing of adjacent photonic crystals is, for example, between g.5 micro^
10微米之間。 又木JBetween 10 microns. Wood J
1253771 17098twf.d〇c/r 化合物半導體材料。舉例來 雜奸粗加，a 牛例木况，廷些ΙΠ-V族化合物半導 體材枓例如是氮化鎵、舰鎵_坤化蘇。 林發明的較佳實_巾，上叙第—型摻雜半導體 二扶Μ Γ i摻料導體層’而第二型摻雜半導體層為一 ρ 暮辦μ炎在例中，上述之第一型摻雜半 J a : ρ型摻雜半導體層，而第二师雜半導 一 η型#雜半導體層。 本电明疋在發光二極體結構的基板表面上形成光子晶 體’以改善第-型摻雜半導體層的m，以增加發光 -極體結構的内部量子效率。此外，本發明之光子晶體更 y以增加正向出射發光二極體結_光能量，以提高發光 一極體結構的外部量子效率。由此可知，本發明之發光二 極體結構具有良好的發光效率。 4為讓本發明之上述和其他目的、舰和優減更明顯 易懂，下文特舉較佳實施例，並配合所附圖式，作詳細說 明如下。 【實施方式】 圖2繪不為本發明之發光二極體結構的剖面示意圖。 請參照圖2,發光二極體結構2〇〇主要是由基板21〇、第一 型摻雜半導體層220、電極222、發光層230、第二型摻雜 半導體層240與電極242所構成。其中，基板21〇的材質 例如是矽、監寶石、碳化矽或尖晶石，且基板21〇具有表 面202及多個位於表面202上的圓柱狀光子晶體(photonic crystal)204 〇 1253771 17098twf.doc/r 承上所述，光子晶體204例如是凸起圖案或凹槽，而 形成這些光子晶體204的方法例如是對基板21〇進行微影 及蝕刻製程，以於其表面202上形成圓柱狀的凸起圖案I 凹槽。特別的疋’光子晶體204是週期性地排列在基板21〇 之表面202上，且兩相鄰之光子晶體的間距(pitch)例如是 介於〇·5微米至1〇微米之間。 ，此外，光子晶體204的直徑例如是介於0·25微米至5 微米之間。而且，這些光子晶體在垂直基板之表面的方向 上之尺寸是介於0·2微米至3微米之間。換言之，呈凸起 圖案之光子晶體的高度例如是介於〇·2微米至3微米之 間，呈凹槽之光子晶體的深度亦例如是介於〇·2微米至3 微米之間。 請繼續參照圖2，第一型摻雜半導體層22〇是配置於 基板210上，以覆蓋這些光子晶體2〇4。特別的是，第一 ，摻雜半導體層220是形成在基板210之表面2〇2的凸起 部位上，而未填入凹槽内。值得一提的是，在形成第一型 6 4半‘脰層220的製程中’這些週期性地排列在基板21〇 之表面202上的光子晶體204可抑制第一型摻雜半導體層 220的局部性的結晶缺陷，並改善其磊晶品質以減少差 排，進而提高發光二極體結構200的内部量子效率。 請再次參照圖2,發光層230、第二型摻雜半導體層 240吳黾極242是依序配置於部分的第一型摻雜半導體層 220上，而電極222則是配置於未被發光層23〇所覆蓋二 部分第一型摻雜半導體層220上。在本實施例中，第一型 1253771 17098twf.doc/r 摻雜半導體層220例如是n型摻雜半導體層，而第二型摻 雜半導體層240例如是ρ型摻雜半導體層。當然，在其他 實施例中，第一型摻雜半導體層22〇也可以是ρ型摻雜半 導體層，此時第二型摻雜半導體層240則為η型摻雜半導 體層。此外，發光層230例如是多重量子井層 (multi-quantum well)。 而且，第一型摻雜半導體層22〇、發光層23〇與第二 型摻雜半導體層240例如是由ΠΙ_ν族化合物半導體材料 所構成。以本實施例來說，第一型摻雜半導體層22〇、發 光層230與第二型摻雜半導體層24〇的材質例如是氮化 鎵、構化鎵或神鱗化鎵。 另外’本貫施例在電極242與第二型摻雜半導體層240 之間更配置有一歐姆接觸層250,用以改善電流在第一型 摻雜半導體層220、發光層230與第二型摻雜半導體層24〇 的傳導均勻性。在本實施例中，歐姆接觸層25〇例如是ρ 型歐姆接觸層。 這些週期性地排列於基板210之表面202上的光子晶 體204除了能夠改善第一型摻雜半導體層22〇的磊晶品質 外，還可以將在第一型摻雜半導體層22〇與第二型摻雜半 V體層220之間橫向傳遞的光線導為正向光，以使其正向 出射發光一極體結構200，進而提高發光二極體結構2〇〇 的外部星子效率。值得注意的是，本發明之光子晶體 具有夕種週期性排列型態，下文將舉例說明這些光子晶體 204的排列型態。 11 1253771 17098twf.doc/r 圖3A至圖3K分別繪示為圖2之光子晶體在各實施例 中的排列型態俯視示意圖。請參照圖3A，在第一實施例 中，光子晶體204例如是排列成mxn的矩陣。其中，㈤與 η均為正整數。特別的是，這些光子晶體2〇4的直徑可以 相同也可以不同。以mxn矩陣的光子晶體2〇4來說，奇數 列的光子晶體204可以是與偶數列的光子晶體2〇4具有不 同的直徑，如圖3B所示。此外，如圖3c所示，位/於mx 丨 η矩陣之(p，q)處的光子晶體2〇4也可以是與位於(p+i，⑴ 及(p，q+i)處的光子晶體具有不同的直徑。其中p、q均為 正正數’且 —1，而 1。 除了矩陣式的排列方式外，光子晶體204也可以排列 成偶數列與奇數列在行方向上不對齊的型態。舉例來說， 如圖3D所示，各奇數列的光子晶體2〇4是在行方向上相 互對齊，而偶數列之光子晶體204則是分別對應至奇數列 中兩相鄰之光子晶體204間的間隔(space)。當然，偶數列 之光子晶體204也可以是與奇數列之光子晶體2〇4具有不 同的直徑，如圖3E所示。 在圖3A至圖3E中，偶數列之光子晶體204的排列間 距(pitch)是與奇數列之光子晶體2〇4的排列間距相同，但 在其他實施例中，偶數列之光子晶體2〇4也可以與奇數列 之光子晶體204具有不同的排列間距。如圖3F及圖3g所 示偶數列之光子晶體204的排列間距例如是奇數列之光 子晶體的兩倍，且偶數列之光子晶體204例如是分別對應 至奇數列中兩相鄰之光子晶體204間的間隔。需要注意的 12 1253771 17098twf.doc/r 疋，此處所謂之間距是指各列中兩相鄰之光子晶體2〇4的 圓心距，而間隔則是指兩相鄰之光子晶體2〇4相隔的距離。 較詳細地來說，圖3F中除了奇數列之光子晶體2〇4 在行方向上相互對齊以外，偶數列之光子晶體2〇4在行方 向上也疋相互對齊的。此外，圖3G中各奇數列的光子晶 脰204疋在行方向上相互對齊，而第k列之偶數列的光子 晶體204則是對應於奇數列及第k+1列偶數列中相鄰之光 • 子晶體204間的間隔。更特別的是，本發明的其他實施例 還可以分別在圖3F及圖3G之偶數列中，於相鄰之光子晶 體204間形成直徑較小的光子晶體2〇如，如圖3H及圖3i 所示。 除此之外，本發明之光子晶體204還可以是以蜂巢狀 的排列型態排列於基板之表面上，如圖3J所示。而在另一 貫施例中，這些光子晶體204也可以是一部份排列成蜂巢 狀’另一部分之光子晶體204b則是被這些排列成蜂巢狀的 光子晶體204a所圍繞，如圖3K所示。其中，光子晶體2〇如 擊 的直徑例如是大於光子晶體2〇4b的直徑。 在此需要說明的是，圖3A至圖3K僅用以說明本發明 之光子晶體204可以是以任何具有週期性的排列型態排列 於基板210之表面202上，其並非用以限定本發明之光子 晶體204的排列方式。 以下將以表1及表2列出本發明之發光二極體結構具 有圖3Α至目：3Κ之光子晶體的發光功率實驗數據，以使熟 習此技藝者更能清楚瞭解本發明之發光二極體結構與習知 13 1253771 17098twf.doc/r 發光二極體結構在發光效率上的差異。其中，表丨是以本 發明線寬弘恤的發光二極體裸晶做測試，表2 則是在將本發明之發光二極體蛛封錢再做測試，而輸 入的測試電流均為20毫安培。此外，表丨及表2中的笋光 功率均是以習知圖丨之發光二極體結構為基準的相對值。1253771 17098twf.d〇c/r Compound semiconductor material. For example, the traitor is rough, a cow is a case of wood, and some of the ΙΠ-V-group compound semiconductor materials are, for example, gallium nitride, ship gallium_Kunhuasu. The preferred embodiment of the invention, the above-mentioned first type-doped semiconductor, the second type of doped Γi-doped conductor layer' and the second type of doped semiconductor layer is a ρ 暮 μ 炎 在 在 在 在 在 在 在 在 在The type doped half J a : p type doped semiconductor layer, and the second division semiconducting n - type # hetero semiconductor layer. The present invention forms photonic crystals on the surface of the substrate of the light-emitting diode structure to improve m of the first-type doped semiconductor layer to increase the internal quantum efficiency of the light-emitting body structure. In addition, the photonic crystal of the present invention is more y to increase the forward exiting light-emitting diode junction light energy to improve the external quantum efficiency of the light-emitting diode structure. From this, it is understood that the light-emitting diode structure of the present invention has good luminous efficiency. 4 In order to make the above and other objects, the ship and the advantages of the present invention more apparent, the preferred embodiments are described below, and in conjunction with the drawings, the detailed description below. [Embodiment] FIG. 2 is a schematic cross-sectional view showing the structure of a light-emitting diode of the present invention. Referring to FIG. 2, the LED structure 2 is mainly composed of a substrate 21, a first doped semiconductor layer 220, an electrode 222, a light-emitting layer 230, a second-type doped semiconductor layer 240, and an electrode 242. The material of the substrate 21 is, for example, germanium, gemstone, tantalum carbide or spinel, and the substrate 21 has a surface 202 and a plurality of cylindrical photonic crystals on the surface 202. 〇1253771 17098twf.doc /r As described above, the photonic crystal 204 is, for example, a convex pattern or a groove, and the method of forming the photonic crystal 204 is, for example, performing a lithography and etching process on the substrate 21 to form a cylindrical shape on the surface 202 thereof. Raised pattern I groove. The special 疋' photonic crystal 204 is periodically arranged on the surface 202 of the substrate 21, and the pitch of two adjacent photonic crystals is, for example, between 微米·5 μm and 1 μm. Further, the diameter of the photonic crystal 204 is, for example, between 0. 25 micrometers and 5 micrometers. Moreover, the size of these photonic crystals in the direction of the surface of the vertical substrate is between 0.2 μm and 3 μm. In other words, the height of the photonic crystal in a raised pattern is, for example, between 微米 2 μm and 3 μm, and the depth of the photonic crystal in the groove is, for example, between 〇 2 μm and 3 μm. Referring to FIG. 2, the first type doped semiconductor layer 22 is disposed on the substrate 210 to cover the photonic crystals 2〇4. Specifically, first, the doped semiconductor layer 220 is formed on the convex portion of the surface 2〇2 of the substrate 210 without being filled in the recess. It is worth mentioning that the photonic crystals 204 periodically arranged on the surface 202 of the substrate 21 can suppress the doping of the first type doped semiconductor layer 220 in the process of forming the first type of 4 4 semi-layers 220. Localized crystal defects and improved epitaxial quality to reduce the difference in retardation, thereby improving the internal quantum efficiency of the light-emitting diode structure 200. Referring again to FIG. 2, the light-emitting layer 230, the second-type doped semiconductor layer 240, the Wu-electrode 242 are sequentially disposed on a portion of the first-type doped semiconductor layer 220, and the electrode 222 is disposed on the un-emitting layer. The second portion of the first type doped semiconductor layer 220 is covered by 23 Å. In the present embodiment, the first type 1253771 17098 twf.doc/r doped semiconductor layer 220 is, for example, an n-type doped semiconductor layer, and the second type doped semiconductor layer 240 is, for example, a p-type doped semiconductor layer. Of course, in other embodiments, the first type doped semiconductor layer 22A may also be a p-type doped semiconductor layer, and the second type doped semiconductor layer 240 is an n-type doped semiconductor layer. Further, the light-emitting layer 230 is, for example, a multi-quantum well. Further, the first type doped semiconductor layer 22, the light emitting layer 23A and the second type doped semiconductor layer 240 are composed of, for example, a ΠΙ? family compound semiconductor material. In this embodiment, the material of the first type doped semiconductor layer 22, the light emitting layer 230 and the second type doped semiconductor layer 24 is, for example, gallium nitride, gallium hydride or gallium. In addition, the present embodiment further includes an ohmic contact layer 250 between the electrode 242 and the second type doped semiconductor layer 240 for improving current flow in the first type doped semiconductor layer 220, the light emitting layer 230 and the second type doping. Uniformity of the semiconductor layer 24〇. In the present embodiment, the ohmic contact layer 25 is, for example, a p-type ohmic contact layer. The photonic crystals 204 periodically arranged on the surface 202 of the substrate 210 can improve the epitaxial quality of the first type doped semiconductor layer 22, and can also be used in the first type doped semiconductor layer 22 and the second. The light transmitted laterally between the doped half V body layers 220 is guided to be forward light to cause it to exit the light emitting body structure 200 in the forward direction, thereby improving the external star efficiency of the light emitting diode structure 2〇〇. It is to be noted that the photonic crystal of the present invention has a chronological periodic arrangement, and the arrangement of these photonic crystals 204 will be exemplified below. 11 1253771 17098 twf.doc/r FIGS. 3A to 3K are respectively schematic plan views showing the arrangement pattern of the photonic crystal of FIG. 2 in each embodiment. Referring to Fig. 3A, in the first embodiment, the photonic crystal 204 is, for example, a matrix arranged in mxn. Among them, (5) and η are both positive integers. In particular, the diameters of these photonic crystals 2〇4 may be the same or different. In the photonic crystal 2〇4 of the mxn matrix, the odd-numbered photonic crystals 204 may have different diameters from the even-numbered photonic crystals 2〇4, as shown in Fig. 3B. Furthermore, as shown in FIG. 3c, the photonic crystal 2〇4 at the (p, q) of the m/ 丨η matrix may also be a photon located at (p+i, (1) and (p, q+i)). The crystals have different diameters, wherein p and q are positive positive numbers ' and -1, and 1. In addition to the matrix arrangement, the photonic crystals 204 can also be arranged in a pattern in which the even columns and the odd columns are not aligned in the row direction. For example, as shown in FIG. 3D, the photonic crystals 2〇4 of each odd-numbered column are aligned with each other in the row direction, and the photonic crystals 204 of the even-numbered columns correspond to the photon crystals 204 of two adjacent ones of the odd-numbered columns, respectively. Of course, the even-numbered photonic crystals 204 may also have different diameters from the odd-numbered photonic crystals 2〇4, as shown in Figure 3E. In Figures 3A to 3E, even-numbered photonic crystals are shown. The arrangement pitch of 204 is the same as the arrangement pitch of the odd-numbered photonic crystals 2〇4, but in other embodiments, the even-numbered photonic crystals 2〇4 may have different arrangements from the odd-numbered photonic crystals 204. The spacing between the even-numbered photonic crystals 204 shown in Figures 3F and 3g For example, the photonic crystals 204 of the odd-numbered columns are twice as large, and the photonic crystals 204 of the even-numbered columns correspond to the spacing between two adjacent photonic crystals 204 in the odd-numbered columns, respectively. Note 12 1253771 17098 twf.doc/r 疋, The term "intermediate distance" refers to the center distance of two adjacent photonic crystals 2〇4 in each column, and the interval refers to the distance between two adjacent photonic crystals 2〇4. In more detail, in Fig. 3F The photonic crystals 2〇4 of the even columns are aligned with each other in the row direction, except that the odd-numbered photonic crystals 2〇4 are aligned with each other in the row direction. Furthermore, the photonic crystals 204 of each odd-numbered column in FIG. 3G are in the row direction. The photonic crystals 204 of the even-numbered columns of the kth column correspond to the spacing between adjacent photonic crystals 204 in the odd-numbered columns and the even-numbered columns in the k+1th column. More particularly, other aspects of the present invention In the embodiment, the photonic crystals 2 having a smaller diameter may be formed between the adjacent photonic crystals 204 in the even columns of FIG. 3F and FIG. 3G, for example, as shown in FIG. 3H and FIG. 3i. The photonic crystal 204 of the invention may also be in the form of a honeycomb The arrangement pattern is arranged on the surface of the substrate as shown in Fig. 3J. In another embodiment, the photonic crystals 204 may also be partially arranged in a honeycomb shape. The other portion of the photonic crystal 204b is The photonic crystal 204a arranged in a honeycomb shape is surrounded, as shown in Fig. 3K, wherein the diameter of the photonic crystal 2, for example, is larger than the diameter of the photonic crystal 2〇4b. It should be noted that Fig. 3A to Fig. 3K The photonic crystals 204, which are merely illustrative of the present invention, may be arranged on the surface 202 of the substrate 210 in any periodic arrangement, which is not intended to define the arrangement of the photonic crystals 204 of the present invention. Hereinafter, the experimental data of the luminous power of the photodiode of the present invention having the photonic crystal of FIG. 3A to 3Κ will be listed in Table 1 and Table 2, so that those skilled in the art can better understand the luminous dipole of the present invention. Body structure and conventional 13 1253771 17098twf.doc / r difference in luminous efficiency of the light-emitting diode structure. Among them, the watch is tested by the light-emitting diode bare crystal of the line width of the present invention, and the test 2 is the test of the light-emitting diode of the present invention, and the input test current is 20 Milliamps. In addition, both the surface light and the bamboo light power in Table 2 are relative values based on the structure of the conventional light-emitting diode.
__習知 相對 1 功率 3A L53 3B 3C 1.56 1.56 3D 1.61 1.66 表1 3F 3G 3H 31 3J 3K 1.53 1.56 1.54 1.56 1.61 1.70__知知 Relative 1 Power 3A L53 3B 3C 1.56 1.56 3D 1.61 1.66 Table 1 3F 3G 3H 31 3J 3K 1.53 1.56 1.54 1.56 1.61 1.70
1——-- 習知 3A 3B 3C 3D 3E 3F 3G 3H 31 3J 3K 相對 功率 1 1.21 1.21 1.25 1.27 1.30 1.23 1.23 1.23 1.31 1.33 1.38 表2 福纺^表1與表2可以清楚得知’本發明之發光二極體結 構/、二知相較之下，具有較佳的發光效率。 ，上所述’本發明之發光二極體結構是在基板表面上 遇湘ί週期性排列的圓柱狀光子晶體，而使基板表面具有 ^性=折射率。因此，當發光層所發出之光線傳遞至基 上蚪，會被這些光子晶體所衍射(diffraction)而往基板 或下方出射，以減少光線在第一型摻雜半導體層與第 14 1253771 17098twf.d〇c/r 一尘穋雜半導體層之間橫向傳遞 提高發光二極體的外部量子效率。β相耗的光能量，進而 此外，在基板表面上的光子晶 上之第-型獅半導體層的局部結 ^场制形成於其 質以減少差排，進而提高發光二晶品 此可具有以 限定本發明，任何熟二::揭==離然其並非用以 範圍當視_之申請專纖圍所界定者=本發明之保護 【圖式簡單說明】 圖1 !會示為習知發光二極體結構的剖面示意圖。 圖2緣示為本發明之發光二極體 圖。 圖3A至圖3K分別繪示為圖2之光子晶體在 中的排列型態俯視示意圖。 、 【主要元件符號說明】 100、200 :發光二極體結構 102 :光線 110、210 :基板 120 : η型摻雜半導體層 122、142、222、242 :電極 130、230 :發光層 140 : ρ型摻雜半導體層 150、250 :歐姆接觸層 15 1253771 17098twf.doc/r 202 :表面 204、204a、204b :光子晶體 220 :第一型摻雜半導體層 240 :第二型摻雜半導體層1——-- 知知3A 3B 3C 3D 3E 3F 3G 3H 31 3J 3K Relative power 1 1.21 1.21 1.25 1.27 1.30 1.23 1.23 1.23 1.31 1.33 1.38 Table 2 Fufang ^ Table 1 and Table 2 can clearly see the 'invention The light-emitting diode structure/, in comparison with the two, has better luminous efficiency. The above-mentioned light-emitting diode structure of the present invention is a cylindrical photonic crystal periodically arranged on the surface of the substrate, so that the surface of the substrate has a refractive index = refractive index. Therefore, when the light emitted by the light-emitting layer is transmitted to the upper surface of the substrate, it is diffracted by the photonic crystals to be emitted toward the substrate or below to reduce the light in the first type doped semiconductor layer and the 141353771 17098twf.d横向c/r The lateral transfer between the dust-doped semiconductor layers increases the external quantum efficiency of the light-emitting diode. The light energy consumed by the β phase, and further, the local junction system of the first-type lion semiconductor layer on the photonic crystal on the surface of the substrate is formed on the surface to reduce the difference, thereby improving the luminescent dimorph. Qualifying the invention, any cooked two:: revealing == is not used to define the scope of the application _ the application of the special fiber enclosure = the protection of the invention [simple description of the diagram] Figure 1 ! will show the light A schematic cross-sectional view of a diode structure. Fig. 2 is a view showing the light emitting diode of the present invention. 3A to 3K are respectively a top plan view showing the arrangement pattern of the photonic crystal of Fig. 2. [Main component symbol description] 100, 200: Light-emitting diode structure 102: Light 110, 210: Substrate 120: n-type doped semiconductor layer 122, 142, 222, 242: electrode 130, 230: light-emitting layer 140: ρ Type doped semiconductor layer 150, 250: ohmic contact layer 15 1253771 17098twf.doc / r 202 : surface 204, 204a, 204b: photonic crystal 220: first type doped semiconductor layer 240: second type doped semiconductor layer
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