1258226 玖、發明說明 【發明所屬之技術領域】 本發明疋有關於一種發光二極體之結構，且特別 是一種具有透明導電層之發光二極體結構。 【先前技術】 發光二極體（Light Emitting Diode ; LED)因具有生 產成本低、結構簡單、低耗電、體積小以及安裝容易 之優勢，而大量運用於照明光源以及顯示器技術中。 其中，又以氮化物為基礎的發光元件，例如氮化鎵 (Gallium Nitride ; GaN)藍光發光二極體，在近幾年的 發光元件市場中’甚受重視。 由於一般的發光二極體結構，在 p型披覆層 (cladding layer)上形成的歐姆接觸層（ohmic contact layer)，具有相當低的載子濃度，如p型氮化鎵接觸層 之載子濃度小於l*l〇18cnT3。因此，使得p型歐姆接 觸層難以有效地將電流分散至整個元件中，且容易造 成電流擁擠（current crowding)現象，而降低了光輸出 的效率。 為解決上述之電流分散不佳的問題’習知發光二 極體係採用鎳/金（Ni/Au)或鉻/金（Cr/Au)等金屬材質作 為一電流分散層（current spreading layer) ’以提升電流 分散的效果。然而，由於透光的需求，以鎳/金或鉻/ 金等金屬材質製作的電流分散層厚度’約僅製作有數 1258226 百埃（Angstrom ; A)左右’如此不易形成結構織密 膜品質，導致無法均勻地分散所有的電流。且 A螺/金 極體 或鉻/金等金屬材質製作的電流分散層，具有的光穿、 性（transmittance)皆低於50%，大量侷限了發光 透 的光輸出強度。 因此近幾年來，則逐漸以透明導電氧化物材料 代鎳/金或鉻/金等金屬材質，作為電流分散層，二取 w同時 提升電流分散效果並改善透光的問題。其中， 又从鋼 錫氧化物（Indium-Tin Oxide ; ITO)為主，錮锡轰 芊、4匕物 的光穿透性約大於9 0 %，可使發光二極體產生的光 塁牙透’而增加光輸出強度。但是，由於一般透明導 電氧化物的折射係數（refractive index)約小於 一 z，如錮 錫氧化物約為1 · 8，難以與折射係數約為2 · 4〜2 s λα 0的氮 化鎵發光二極體，形成良好的匹配，故容易弓丨起元件 内部產生光全反射的現象，導致發光二極體的光輸出 強度減少，進而影響發光二極體元件之亮度呈現。 另外，也因為銦錫氧化物直接與p型氮化鎵層接 合時，無法擁有良好的電接觸特性，故影響了電流分 散的實際成效，並同時危害元件特性的提升。 【發明内容】 本發明之目的之一是在提供一種具有透明導電層的 發光二極體，不但可對元件達成良好的電流分散效果，更 有效提升發光二極體的光輸出強度，而大幅增進元件的品 1258226 質與亮度呈現。另外，本發明亦可改善直接設置透明導電 層時，與發光二極體之間所形成的接觸不佳現象。 根據本發明之上述目的，提出一種具有透明導電層的 發光二極體。此發光二極體，依序包含一第一電性半導體 層、一主動層、一第二電性半導體層、一高折射率接觸層 以及一透明導電層。利用具有低阻值特性的透明導電層之 設置，以增進7G件内的電流分散效果，更利用具有高折射 係數的透明導電材質，製作成高折射率接觸層，並設置於 透明導電層與第二電性半導體層之間。 其中，透明導電層可為一銦錫氧化物層，而高折射率 接觸層的材質，則選用折射係數介於透明導電層與第二電 性半導體層之間的透明導電材料，例如折射係數^於銦錫 氧化物的銦鈽氧化物，以與第二電性半導體層的折射係數 匹配，而誘使元件内的光輸出增加，進而提升發光二極體 的光輸出強度。同日夺，可藉由高折射率接觸層的材質選 取，使高折射率接觸層與第二電性半導體層的接觸性良 好，以改善透明導電層直接與第二電性半導體層接觸時， 因接觸特性不佳而影響電流分散作用之現象。 除此之外，也可將高折射率接觸層製作為具有開口的 結構，以使高折射率接觸層的使用材質，可另外選用具有 高折射係數的絕緣材料，並因開口結構的設計，而同時使 後續透㈣電層的形成，㉟自然具有表面粗化的特性。位 於高折射率接觸層中的開口，係暴露出部分的第二電性半 導體層，使覆蓋於高折射率接觸層上方的透明導電層，能 1258226 同時形成於這些開口之中，而與第二電性半導體層接觸， 以保有透明導電層對元件内的電流分散作用。 因此，本發明之發光二極體，除了以低阻值的透明導 電層，對元件内部提供電流分散的作用之外，更利用高折 射率接觸層的設置，以增加發光二極體的光輸出強度，進 而提升元件的品質與亮度。另外，藉由高折射率接觸層的 材質選取’可改善透明導電層與發光二極體之間的不良接 觸性’而維持良好的電流分散成效，以提升光輸出效率。 同日守’利用咼折射率接觸層的幾何結構設計，使透明導電 層具有表面粗化的特性，以利於降低元件内之光全反射的 現象’進而更加提升光輸出的強度。 【實施方式】 本發明係提供一種具有透明導電層的發光二極體結 構’以氮化鎵（GaN)發光二極體為例，係選用銦錫氧化物 (Indium-Tin Oxide ; ITO)製作一透明導電層，以作為電流 分散層（current spreading layer)，並再製作一具有高折射 係數（refractive index)的薄膜夾層，位於透明導電層與P 型氮化鎵結構之間。以減小對元件發光的全反射現象，進 而提升發光二極體的光輸出強度。以下將以實施例對本發 明之方法加以詳細說明。 實施例1 本發明揭露了一種具有透明導電層的發光二極體結 1258226 構。參照第1圖，第1圖係為依照本發明第一較佳實施例 的發光二極體結構之剖面示意圖。 在第1圖中，一氮化鎵發光元件1 〇〇，係為以藍寶石 (sapphire)作為基板102的一發光二極體，在基板1〇2上 則具有一磊晶結構，依序包含一 η型氮化鎵半導體層 104, 一具有多層量子井（Multi-Quantum Well)結構之發光 主動層106，以及一 p型氮化鎵半導體層108。同時，分 別在P型氮化鎵半導體層108之部分表面上，設置有一陽 極電極112，以及在η型氮化鎵半導體層1〇4之上，設置 有一陰極電極114。 另外，在ρ型氮化鎵半導體層108上，具有一透明導 電層110 ’材質例如為銦錫氧化物，具有低電阻之特性， 以作為電流分散層，有助於將電流由ρ型氮化鎵半導體層 108的位置，有效地傳送分散至η型氮化鎵半導體層ι〇4 上。本實施例更在透明導電層110與ρ型氮化鎵半導體層 108之間，設置一具有高折射係數的薄膜夾層，以作為一 高折射率接觸層109,有助於提升氮化鎵發光元件1〇〇的 光輸出強度。 其中’局折射率接觸層109的材質，係選用折射係數 高於2.0的的透明導電材料，例如錮鈽氧化物 (IndiUm-Cerium 0xide)或銦鋅氧化物（lndium_zincBACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a light-emitting diode, and more particularly to a light-emitting diode structure having a transparent conductive layer. [Prior Art] Light Emitting Diodes (LEDs) are widely used in illumination sources and display technologies because of their low production cost, simple structure, low power consumption, small size, and easy installation. Among them, nitride-based light-emitting elements, such as gallium nitride (GaN) blue light-emitting diodes, have received much attention in the market of light-emitting elements in recent years. Due to the general light-emitting diode structure, an ohmic contact layer formed on a p-type cladding layer has a relatively low carrier concentration, such as a carrier of a p-type gallium nitride contact layer. The concentration is less than l*l〇18cnT3. Therefore, it is difficult for the p-type ohmic contact layer to effectively disperse current into the entire element, and it is easy to cause current crowding, which reduces the efficiency of light output. In order to solve the above problem of poor current dispersion, the conventional light-emitting diode system uses a metal material such as nickel/gold (Ni/Au) or chromium/gold (Cr/Au) as a current spreading layer. Improve the effect of current dispersion. However, due to the demand for light transmission, the thickness of the current dispersion layer made of a metal material such as nickel/gold or chrome/gold is only about 1258226 angstroms (Angstrom; A), so it is difficult to form a structure woven film quality, resulting in It is not possible to evenly distribute all the current. The current dispersion layer made of a metal material such as A-spiral/gold or chrome/gold has a light transmittance of less than 50%, and a large amount of light output intensity is limited. Therefore, in recent years, a transparent conductive oxide material has been used as a metal dispersion material such as nickel/gold or chromium/gold as a current dispersion layer, and at the same time, the current dispersion effect is improved and the problem of light transmission is improved. Among them, it is mainly from tin-tin oxide (Indium-Tin Oxide; ITO), and the light penetration of bismuth and tin-tellurum is more than 90%, which can make the light-emitting teeth of the light-emitting diodes 'And increase the light output intensity. However, since the refractive index of a generally transparent conductive oxide is less than about one z, such as a tin-tin oxide of about 1·8, it is difficult to emit GaN with a refractive index of about 2·4~2 s λα 0 . The diodes form a good match, so it is easy to bow the phenomenon of total light reflection inside the component, resulting in a decrease in the light output intensity of the light-emitting diode, thereby affecting the brightness of the light-emitting diode element. In addition, since indium tin oxide is directly bonded to the p-type gallium nitride layer, it does not have good electrical contact characteristics, which affects the actual effect of current dispersion and at the same time impairs the characteristics of the device. SUMMARY OF THE INVENTION One object of the present invention is to provide a light-emitting diode having a transparent conductive layer, which not only achieves a good current dispersion effect on components, but also effectively improves the light output intensity of the light-emitting diode, and greatly enhances The quality of the component 1258226 is presented in terms of quality and brightness. Further, the present invention can also improve the poor contact with the light-emitting diode when the transparent conductive layer is directly disposed. According to the above object of the present invention, a light-emitting diode having a transparent conductive layer is proposed. The light emitting diode comprises a first electrical semiconductor layer, an active layer, a second electrical semiconductor layer, a high refractive index contact layer and a transparent conductive layer. The transparent conductive layer having a low resistance characteristic is used to enhance the current dispersion effect in the 7G device, and a transparent conductive material having a high refractive index is used to form a high refractive index contact layer, and is disposed on the transparent conductive layer and the first Between two electrical semiconductor layers. Wherein, the transparent conductive layer may be an indium tin oxide layer, and the material of the high refractive index contact layer is a transparent conductive material having a refractive index between the transparent conductive layer and the second electrical semiconductor layer, such as a refractive index ^ The indium antimony oxide of the indium tin oxide matches the refractive index of the second electrical semiconductor layer to induce an increase in the light output in the element, thereby increasing the light output intensity of the light emitting diode. In the same day, the contact between the high refractive index contact layer and the second electrical semiconductor layer is good by selecting the material of the high refractive index contact layer, so as to improve the direct contact of the transparent conductive layer with the second electrical semiconductor layer. Poor contact characteristics affect the phenomenon of current dispersion. In addition, the high refractive index contact layer can also be made to have an open structure, so that the material used for the high refractive index contact layer can be additionally selected from an insulating material having a high refractive index, and due to the design of the open structure. At the same time, the subsequent formation of the (four) electrical layer, 35 naturally has the characteristics of surface roughening. An opening in the high refractive index contact layer exposes a portion of the second electrically conductive semiconductor layer such that a transparent conductive layer overlying the high refractive index contact layer can be formed simultaneously in the openings 1258226, and second The electrically conductive layer is in contact to retain a current dispersion of the transparent conductive layer within the component. Therefore, the light-emitting diode of the present invention uses a low-resistance transparent conductive layer to provide a current dispersion inside the device, and further utilizes a high refractive index contact layer to increase the light output of the light-emitting diode. Strength, which in turn improves the quality and brightness of the component. Further, by selecting the material of the high refractive index contact layer to improve the poor contact between the transparent conductive layer and the light-emitting diode, a good current dispersion effect is maintained to improve the light output efficiency. On the same day, the geometric design of the 咼 refractive index contact layer is used to make the transparent conductive layer have the characteristics of surface roughening, so as to reduce the phenomenon of total light reflection in the element, thereby further enhancing the intensity of light output. [Embodiment] The present invention provides a light-emitting diode structure having a transparent conductive layer. Taking a gallium nitride (GaN) light-emitting diode as an example, an indium-tin oxide (ITO) is used. The transparent conductive layer acts as a current spreading layer, and a thin film interlayer having a high refractive index is formed between the transparent conductive layer and the P-type gallium nitride structure. In order to reduce the total reflection phenomenon of the light emission of the element, the light output intensity of the light-emitting diode is increased. The method of the present invention will be described in detail below by way of examples. Embodiment 1 The present invention discloses a light-emitting diode junction 1258226 having a transparent conductive layer. Referring to Fig. 1, there is shown a cross-sectional view of a light emitting diode structure in accordance with a first preferred embodiment of the present invention. In Fig. 1, a gallium nitride light-emitting device 1 is a light-emitting diode having sapphire as the substrate 102, and has an epitaxial structure on the substrate 1〇2, including one in sequence. The n-type gallium nitride semiconductor layer 104, a light-emitting active layer 106 having a multi-quantum-well structure, and a p-type gallium nitride semiconductor layer 108. Meanwhile, an anode electrode 112 is disposed on a portion of the surface of the P-type gallium nitride semiconductor layer 108, and a cathode electrode 114 is disposed over the n-type gallium nitride semiconductor layer 1?4. In addition, on the p-type gallium nitride semiconductor layer 108, a transparent conductive layer 110' material such as indium tin oxide has a low resistance characteristic as a current dispersion layer to facilitate nitridation of current by p-type. The position of the gallium semiconductor layer 108 is efficiently transferred to the n-type gallium nitride semiconductor layer ι4. In this embodiment, a thin film interlayer having a high refractive index is disposed between the transparent conductive layer 110 and the p-type gallium nitride semiconductor layer 108 to serve as a high refractive index contact layer 109, which helps to improve the gallium nitride light emitting device. 1〇〇 light output intensity. The material of the 'refractive index contact layer 109 is a transparent conductive material having a refractive index higher than 2.0, such as indium oxide (IndiUm-Cerium 0xide) or indium zinc oxide (lndium_zinc).
Oxide)’以使高折射率接觸層1〇9具有的折射率大於透明 導電層1H)’且可與折射係數為2.4~2·5的氮化鎵相匹配。 銦錦氧化⑯的折射係數約& 2.3 ’氧化㈣折射係 1258226 m rtq 數則約為2·1 η ，日 〜τ<ι貝丹有的折射率 係介於氮化鎵與透明導電層110的折射率之間，如此，將 更有效地引導氣化鎵發光元件100所產生的光向外輸 出’減少元件内光全反射的現象’以提升發光元件10^ 的光輪出強度。 除此之外，由於高折射率接觸層109的材質，亦為一 透明導電材料，具有與透明導電層110相近的光穿透特Oxide) is such that the high refractive index contact layer 1〇9 has a refractive index larger than that of the transparent conductive layer 1H)' and can be matched with gallium nitride having a refractive index of 2.4 to 2.5. The refractive index of indium sulphide 16 is about & 2.3 'oxidation (iv) refracting system 1258226 m rtq number is about 2·1 η, day ~ τ < ι Betan has a refractive index between GaN and transparent conductive layer 110 Between the refractive indices, in this way, the light generated by the gallium hydride light-emitting element 100 is more efficiently guided to output a phenomenon of "reducing total light reflection in the element" to enhance the light-emitting intensity of the light-emitting element 10^. In addition, due to the material of the high refractive index contact layer 109, it is also a transparent conductive material having a light transmittance similar to that of the transparent conductive layer 110.
性，以使發光元件1〇〇的光穿透情形不受影響。同時，接 觸層109的材質亦具有低電阻的特性，例如銦鈽氧化物 即具有約i*i〇-3ohm-cm的低電阻值，以使透明導電層ιι〇 對P型氮化鎵半導體層108的電流分散效果，不受接0觸層 109的影響。 θ 卜本實施例中，利用一電阻值系勺1*1〇-4 Ohm,的銦錫 氧化物作為透明導電電流分散層，以達到極佳的電流分散 t果並藉由间折射率的透明薄膜夾層，設置於透明導 電電流，散層與P型氮化鎵之間，以改善鋼錫氧化物直接 與P型氮化鎵接觸時，容易造成光全反射的缺點，進而提 升發光二極體的光輸出強度，並提高元件的亮度。同時， 亦月b改善以銦錫氧化物直接與P型氮化鎵接觸時，易有電 接觸特性不佳的現象，例如選用功函數（WGiicfunetion)大 於妇錫氧化物的銦#氧化物，以作為具有高折射率的透明 薄膜，層可與p型氮化鎵達到較佳的電接觸性，進而提 升電流分散層對元件内實際的電流分散成效，以增加元件 的光輸出效率。 11 1258226 —施例 本發明揭露了另一種具有透明導電層的發光 姑構。參照第2圖’第2圖係為依照本發明第二較 > 例的發光二極體結構之剖面示意圖。 又 掏 在第2圖中’一氮化鎵發光元件2〇〇,係同樣例如以 藍寶石作為基板202,並在基板2〇2上依序包含_n 化鎵半導體層204’ 一具有多層量子井結構之‘光Sexuality so that the light penetration of the light-emitting element 1〇〇 is not affected. At the same time, the material of the contact layer 109 also has a low resistance characteristic, for example, indium bismuth oxide has a low resistance value of about i*i 〇 -3 ohm-cm, so that the transparent conductive layer ιι is opposed to the P-type gallium nitride semiconductor layer. The current dispersion effect of 108 is not affected by the contact layer 109. θ In this embodiment, a resistive value of 1*1〇-4 Ohm, indium tin oxide is used as a transparent conductive current dispersion layer to achieve excellent current dispersion and transparency by mutual refractive index. The film interlayer is disposed between the transparent conductive current and the diffusion layer and the P-type gallium nitride to improve the shortcoming of the light total reflection when the steel tin oxide is directly contacted with the P-type gallium nitride, thereby improving the light-emitting diode. The light output intensity and increase the brightness of the component. At the same time, it is also easy to have poor electrical contact characteristics when indium tin oxide is directly contacted with P-type gallium nitride. For example, a work function (WGiicfunetion) is selected to be larger than indium oxide of tin oxide. As a transparent film with a high refractive index, the layer can achieve better electrical contact with p-type gallium nitride, thereby improving the actual current dispersion effect of the current dispersion layer on the component to increase the light output efficiency of the component. 11 1258226 - Example The invention discloses another luminescent structure having a transparent conductive layer. Referring to Fig. 2', Fig. 2 is a schematic cross-sectional view showing a structure of a light-emitting diode according to a second comparative example of the present invention. Further, in FIG. 2, a gallium nitride light-emitting device 2 is similarly made of, for example, sapphire as a substrate 202, and sequentially includes a GaN-based semiconductor layer 204' on the substrate 2'2. Structure of 'light
206’以及一 p型氮化鎵半導體層2〇8。另外，亦分 曰 塑氮化鎵半導體層2〇8之部分表面上，設置有—陽極電」 212’以及在n型i化鎵半導體層綱之上，設置 電極214。 m 對於具有電流分散作用的透明導電層21〇，則如同第 -實施例，例如選用具有低電阻特性的銦錫氧化物。秋 而，與第一實施例不同的是，可選用絕緣性質的材料，來206' and a p-type gallium nitride semiconductor layer 2〇8. Further, an electrode 214 is provided on a portion of the surface of the plastic gallium nitride semiconductor layer 2 to 8 which is provided with an anode electrode 212' and over the n-type gallium semiconductor layer. m For the transparent conductive layer 21A having current dispersion, as in the first embodiment, for example, indium tin oxide having low resistance characteristics is selected. In the autumn, unlike the first embodiment, an insulating material can be used.
作為透明導電層21G與P型氮化鎵半導體層208之間的高 折射率接觸層209。 在第二實施例中，高折射率接觸層2〇9的材質，係 選用折射係數大於2·〇的絕緣介電材料，例如可為二氧化 鈦（Ti〇2)、二氧化铪（Hf〇2)、五氧化二叙（Ta2〇5)或氧化锆 (ZrO)為了不影響透明導電層2ig對p型氮化鎵半導體 :08的電連接性，而失去電流分散之作用，係將絕緣的 p折射率接觸層2〇9，製作為具有開口 的結構，使透 導電層210仍能藉由開π 2〇7，*與p型氮化鎵半導體 12 1258226 層208接觸。其中，開口 207之形成，係較佳控制為使開 口 207兩側之高折射率接觸層209，具有邊長約0.54.〇 /z m之尺寸。 同時，由於高折射率接觸層209中的開口 207設置， 使透明導電層2 1 0覆蓋於高折射率接觸層209之上時，即 可直接形成表面起伏的結構態，而具有透明導電層2 j 〇 的表面粗化效果。利用透明導電層2 1 〇的表面粗化特性， 可有助於降低元件内光全反射的現象，以提升光輸出的強 度。 應用第二實施例，同樣利用低電阻值的銦錫氧化物作 為透明導電電流分散層，以達到極佳的電流分散效果，並 藉由一具有開口結構的高折射率絕緣層，以改善銦錫氧化 物與p型氮化鎵接觸時，產生的光全反射問題。另外，更 可形成透明導電層表面粗化的效果，而同時具有降低光全 反射的功用，進而更有效地提升發光二極體的光輸出強 度’使元件的亮度大幅提高。 根據上述本發明之實施例可知，應用本發明之發光二 極體，可保有透明導電層的電流分散作用，以及良好的光 穿透特性，同時，亦藉由高折射率接觸層的設置，而更加 提=元件的光輸出強度。另外，更可藉由高折射率接觸層 材貝的選擇，而改善透明導電層與發光二極體之間的不良 接觸l± W維持良好的電流分散成效，進而提升光輸出效 率同日守利用局折射率接觸層的幾何結構設計，可降低 元件内光全反射的現象，以更加提高光輸出的強度。 13 1258226 ^明不只侷限於使用在氮化鎵發光二極體 上，其他發光二極體元件之製作，亦可藉由本發明：： 法，而大幅提升產品的特性。 万 耗本發明已以實施例揭露如上，然其並非用以限 疋本發明’任何熟習此技藝者，在不脫離本發明之精神和 範圍内，當可作各種之更動與㈣，因此本發明之保護範 圍當視後附之申請專利範圍所界定者為準。 【圖式簡單說明】 φ 為讓本發明之上述特徵、方法、目的及優點能更明顯 易懂，配合所附圖式，加以說明如下： 第1圖係為依照本發明第一較佳實施例的發光二極 體結構之剖面示意圖；以及 第2圖係為依照本發明第二較佳實施例的發光二極 體結構之剖面示意圖。As the high refractive index contact layer 209 between the transparent conductive layer 21G and the P-type gallium nitride semiconductor layer 208. In the second embodiment, the material of the high refractive index contact layer 2〇9 is an insulating dielectric material having a refractive index greater than 2·〇, such as titanium dioxide (Ti〇2) or cerium oxide (Hf〇2). , bismuth oxide (Ta2〇5) or zirconia (ZrO) in order to not affect the electrical connection of the transparent conductive layer 2ig to p-type gallium nitride semiconductor: 08, and lose the role of current dispersion, the insulation p-refraction The contact layer 2〇9 is formed to have an open structure so that the conductive layer 210 can still be in contact with the p-type gallium nitride semiconductor 12 1258226 layer 208 by opening π 2〇7. The opening 207 is preferably formed such that the high refractive index contact layer 209 on both sides of the opening 207 has a side length of about 0.54. 〇 / z m. At the same time, since the opening 207 in the high refractive index contact layer 209 is disposed, when the transparent conductive layer 210 is overlaid on the high refractive index contact layer 209, the surface undulating structural state can be directly formed, and the transparent conductive layer 2 is provided. j 〇 surface roughening effect. The surface roughening property of the transparent conductive layer 2 1 可 can help reduce the phenomenon of total light reflection in the element to enhance the light output intensity. Applying the second embodiment, the low-resistance indium tin oxide is also used as the transparent conductive current dispersion layer to achieve an excellent current dispersion effect, and the indium tin is improved by a high refractive index insulating layer having an open structure. The problem of total light reflection when the oxide is in contact with p-type gallium nitride. Further, the effect of roughening the surface of the transparent conductive layer can be formed, and at the same time, the function of reducing the total reflection of light can be further enhanced, and the light output intensity of the light-emitting diode can be more effectively improved to greatly increase the brightness of the element. According to the embodiment of the present invention described above, the light-emitting diode of the present invention can maintain the current dispersion of the transparent conductive layer and good light transmission characteristics, and at the same time, by the arrangement of the high refractive index contact layer. More mention = the light output intensity of the component. In addition, the selection of the high refractive index contact layer material can improve the poor contact between the transparent conductive layer and the light emitting diode, and maintain a good current dispersion effect, thereby improving the light output efficiency. The geometrical design of the refractive index contact layer can reduce the phenomenon of total light reflection in the component to further increase the intensity of the light output. 13 1258226 ^ It is not limited to the fabrication of other light-emitting diode elements used in gallium nitride light-emitting diodes, and the characteristics of the products can be greatly improved by the invention: method. The present invention has been disclosed in the above embodiments, but it is not intended to limit the invention to those skilled in the art, and the present invention can be modified and/or varied without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application. BRIEF DESCRIPTION OF THE DRAWINGS The above features, methods, objects, and advantages of the present invention will be more apparent and understood from the accompanying drawings. FIG. 1 is a first preferred embodiment of the present invention. A schematic cross-sectional view of a light emitting diode structure; and Fig. 2 is a schematic cross-sectional view of a light emitting diode structure in accordance with a second preferred embodiment of the present invention.
元件代表符號簡單說明】 100、200 :發光元件 104 、 108 、 204 、 208 : 106、206 :主動層 • 110、210:透明導電層 102 > 202 ：基板 氮化鎵半導體層 109、209 :接觸層 11 2、114、2 12、2 14 :電極 207 :開口 14Brief Description of Component Representation Symbols 100, 200: Light-emitting elements 104, 108, 204, 208: 106, 206: Active layer • 110, 210: Transparent conductive layer 102 > 202: Substrate gallium nitride semiconductor layer 109, 209: Contact Layer 11 2, 114, 2 12, 2 14 : electrode 207: opening 14