595022 玖、發明說明 【發明所屬之技術領域】 本發明是有關於一種發光元件（Light Emitting Device)，且特別是有關於一種具有高亮度以及低順向電 壓（Forward Voltage)之半導體發光元件。 【先前技術】 氧化銦錫（Indium Tin Oxide ; ITO)已廣泛地應用在具 有氮化銦鎵（InGaN)系列材料之半導體光電元件，例如薄 膜電晶體液晶顯示器（Thin Film Transistor Liquid Crystal Display ; TFT-LCD)、有機發光元件（〇rganic Light Emitting Device ; OLED)、以及發光元件等。其中，氧化 铜錫係用以做為半導體光電元件之導電窗戶層，以供電流 散佈與光透射。由於氧化銦錫與p型氮化鎵（GaN)之間的 歐姆接觸不容易，因此目前關切之技術重點在於尋求低且 穩定之操作順向電壓（F〇rward Voltage ; Vf)。 順向電壓可藉由在氧化銦錫層以及p型氮化鎵接觸 層之間加入媒介層（Agent Layer)來加以降低。例如，在 Okazaki等人所提出之美國專利編號第5,977,566號中， 係利用一些金屬，例如鎂（Mg)、鎳（Ni)、金（An)、鋅（Zn)、 或欽（Ti)，來作為媒介層。另外，在Ming_加抓等人所提 出之美國專利編號第6,〇78,〇64號中，係利用高劑量摻雜 之p型接觸層，例如氮化銦鎵（InGaN)、砷化鎵（GaAs)、 砷化鋁鎵（AlGaAs)、或磷化鎵（Gap)，來作為媒介層。 然而，位於氧化銦錫層以及P型氮化鎵接觸層之間的 媒介層會吸收輸出之光強度，且由於媒介層中之高摻雜濃 6 595022 度會於操作期間在媒介層與接觸層之間造成載子擴散，而 導致順向電壓呈現不穩定狀態。 另一方面’在半導體光電元件之製作中，利用氧化銦 錫層作為電流散佈層並使此氧化銦錫層覆蓋在鎳/金透明 導電層上來提升光輸出已是眾所週知之技術。例如，在 Oberman等人所提出之美國專利編號第5,925,897號中， 係在氧化錮錫層與p型氮化銦鎵接觸層之間加入薄金/鎳 層。在Lin等人所提出之美國專利編號第6,465,8〇8號中， 係利用點狀之透明導電層來減少光吸收面積而達到提升 光輸出的目的。此外，在Lud〇wise等人所提出之美國專 利第6,287,947號中，係在氧化銦錫層與p型氮化録接觸 層之間加入多層透明導電層。 然而，在上述之發明中，受到磊晶圓之表面粗糙度不 =或由於氫保護效應所引發之變化，會造成較差之順向電 壓與兒流之可再現率（Repr〇ducibility)。 【發明内容】595022 发明 Description of the invention [Technical field to which the invention belongs] The present invention relates to a light emitting device (Light Emitting Device), and more particularly to a semiconductor light emitting device with high brightness and low forward voltage. [Previous Technology] Indium Tin Oxide (ITO) has been widely used in semiconductor optoelectronic elements with indium gallium nitride (InGaN) series materials, such as Thin Film Transistor Liquid Crystal Display; TFT- LCD), organic light emitting device (OLED light emitting device; OLED), and light emitting devices. Among them, copper tin oxide is used as a conductive window layer for semiconductor optoelectronic components for current spreading and light transmission. Since the ohmic contact between indium tin oxide and p-type gallium nitride (GaN) is not easy, the current technical focus is to find a low and stable operating forward voltage (Vf). The forward voltage can be reduced by adding an agent layer between the indium tin oxide layer and the p-type gallium nitride contact layer. For example, in U.S. Patent No. 5,977,566, proposed by Okazaki et al., Some metals such as magnesium (Mg), nickel (Ni), gold (An), zinc (Zn), or chitin (Ti) are used. As a media layer. In addition, in US Pat. No. 6, 〇78, 〇64 proposed by Ming Jiajia et al., P-type contact layers doped with high doses, such as indium gallium nitride (InGaN), gallium arsenide, etc. (GaAs), aluminum gallium arsenide (AlGaAs), or gallium phosphide (Gap) as the intermediary layer. However, the dielectric layer between the indium tin oxide layer and the P-type gallium nitride contact layer will absorb the output light intensity, and due to the high doping concentration of 6 595022 degrees in the dielectric layer, the dielectric layer and the contact layer will be exposed during operation. Carrier diffusion occurs between them, resulting in an unstable state of forward voltage. On the other hand, in the manufacture of semiconductor optoelectronic elements, it is a well-known technique to use an indium tin oxide layer as a current spreading layer and cover this indium tin oxide layer on a nickel / gold transparent conductive layer to improve light output. For example, in US Pat. No. 5,925,897 proposed by Oberman et al., A thin gold / nickel layer is added between the hafnium tin oxide layer and the p-type indium gallium nitride contact layer. In U.S. Patent No. 6,465,808 proposed by Lin et al., A point-shaped transparent conductive layer is used to reduce the light absorption area to achieve the purpose of increasing light output. In addition, in U.S. Patent No. 6,287,947 proposed by Ludowwise et al., A multilayer transparent conductive layer is added between the indium tin oxide layer and the p-type nitrided contact layer. However, in the above-mentioned invention, the surface roughness of the epitaxial wafer is not equal to or caused by the hydrogen protection effect, which will result in poor reproducibility of forward voltage and flow. [Summary of the Invention]
I本鲞月之目的就是在提供一種發光元件，其接觸層至 少^括混合超晶格（Hybdd〜他⑴⑻結構，其中此混合 超曰曰格結構至少包括二到五對寬能隙材料層與低能隙材 料層例如氮化鋁鎵層/氮化鎵層（A1GaN Layer/GaN μ y )所構成之第一超晶袼結構位於侷限層上。由於此 f -超晶格結構可散佈電洞載子，目此可提升發光元件之 、 另一目的就是在提供一種發光元件，接觸 之 合超晶格纟士谱 、、"構至乂包括一至二對寬能隙材料層與 7 595022 能隙材料層，例如鋁化鎵層/氮化銦鎵層 LayeiVInGaN Layer)，所構成之第二超晶袼結構位於第一 超晶格結構上。由於此第二超晶袼結構厚度可對p型載子 或η型載子提供隧穿接觸（Tunneling c〇ntact)，因此可對 順向電壓差加以設計而使順向電壓差維持一定值，進而可 使順向電壓維持穩定。 根據本發明之上述目的，提出一種發光元件，至少包 括·· -接觸層，其中此接觸層至少包括一第一超晶袼 以及一第二超晶格結構直接位於第一超晶格結構上，且第 -超晶格結構至少包括複數個寬能隙氮化物半導體層以 及複數個窄能隙氮化物半導體層交互堆疊，而第二超I格 結構至少包括至少—寬能隙氮化物半導體層以及至少一 窄能隙氮化物半導體層交互堆疊；以及一透明導電層直接 位於接觸層之第=^晶格結構之一表面上。 〃依照本發明一較佳實施例，第一超晶格結構之寬能隙 匕物Γ導體層的材質為氮化紹鎵’且第一超晶格結構之 乍能隙氮化物半導體層之材質為氮化鎵。此外，第一超晶 I構：見此隙虱化物半導體層與窄能隙氮化物半導體 日第一超日日格結構之寬能隙氮化 物h體層之材質為氮化鎵，且第二超晶格結構之窄能隙 氮化物半導體層之材皙Α ^ )产 又材貝為虱化銦鎵，而第二超晶格結構之 寬能隙氮化物半導轉爲&办& ^ > 體曰一乍月b隙氮化物半導體層之數量 介於1至2之間。 s 在本發明之另_ ^ , 2…之第和 實施例中，第-超晶格結構係由 s弟—4晶格層所構成，其中[超晶格層可為 氮化鋁鎵層/氮化鎵層/氮化鋁鎵層堆叠 格結構係由…層之第二超晶格層;t構成，其中第二超 晶格層可為氮化鎵層/氮化銦鎵層/氮化鎵層堆疊結構。 由於第-超晶格結構可散佈载子，且第二超晶格結構 可供載子㈣’因此可提升發光元件之亮度，並獲得穩定 之低順向電壓。 【實施方式】 本發明揭露-種發光元件，至少包括由混合超晶格結 構所構成之接觸可散佈冑洞載子，並可提供載子隨穿 接觸:且氧化物透明層可直接沉積纟此接觸層1。因此， 可提冋毛光元件之冗度，並獲得穩定且較低之順向電壓。 為了使本發明之敘述更加詳盡與完備，可參照下列描述並 配合第1圖與第2圖之圖示。 明乡π第1圖’第1圖係繪示依照本發明一較佳實施 例的一種發光7C件之結構剖面圖。本發明之一較佳實施例 之發光元件結構可包括依序堆疊之透明之基板1〇〇、。型 半V體層102、主動層（Active Layer)i〇4、ρ型揭限層 (Cladding Layer) 106、超晶格結構1〇8、超晶格結構丨1〇、 以及透明導電層112。其中，超晶格結構1〇8與超晶格結 構110構成一接觸層，且超晶格結構1〇8與超晶格結構 11 〇形成混合超晶格結構。 η型半導體層1 〇2之材質可例如為n型氮化鎵，p型 侷限層106之材質可例如為？型氮化嫁，且透明導㈣ 112之材質可例如為氧化銦錫。此外，超晶格結構1⑽可 例如由二至五對交互堆疊之寬能隙半導體材料層以及窄 錢+導體材料層所構成，其中寬㈣半導體材 :半；體材料層之材質可例如為P型穆雜之氮化物： ㈣二此較佳實施例中，超晶格結構108之寬能隙半導 體材料層的材料為氮化㈣，且超晶格結構⑽之窄 半導體材料層的材料為氮化鎵'然，超晶格結構108亦可 由一至三組依序堆疊之寬能隙半導體材料層、窄能隙半導 f材料層、以及寬能隙半導體材料層所構成，其中上述之 寬能隙半導體材料層與窄能隙半導體材料層之材質 如為p型摻雜之氮化物半導體，且上下兩層寬能隙半導體 材料層之材貝較佳為氮化鎵，中間之窄能隙半導體材 層之材質較佳為氮化鎵。 之厚度 導體材 此外，超晶格結構108之寬能隙半導體材料層 較佳是小於1()〇A，而超晶格結構⑽之窄能隙半 料層之厚度較佳是小於500A。The purpose of this month is to provide a light-emitting element whose contact layer includes at least a hybrid superlattice (Hybdd ~ heterogeneous structure, where the hybrid superlattice structure includes at least two to five pairs of wide band gap material layers and The first supercrystalline gadolinium structure composed of a low energy gap material layer such as an aluminum gallium nitride layer / gallium nitride layer (A1GaN Layer / GaN μ y) is located on the confined layer. Because this f-superlattice structure can disperse electrical holes The purpose is to improve the light-emitting element. Another purpose is to provide a light-emitting element. The contact spectrum of the superlattice spectrum is composed of one to two pairs of wide energy gap material layers and 7 595022 energy gap. A material layer, such as a gallium aluminide layer / indium gallium nitride layer (LayeiVInGaN Layer), forms a second supercrystalline rhenium structure on the first superlattice structure. Since the thickness of the second supercrystalline erbium structure can provide tunneling contact for p-type carriers or n-type carriers, the forward voltage difference can be designed to maintain the forward voltage difference to a certain value. Furthermore, the forward voltage can be kept stable. According to the above object of the present invention, a light-emitting element is provided, including at least a contact layer, wherein the contact layer includes at least a first superlattice and a second superlattice structure directly on the first superlattice structure, The first superlattice structure includes at least a plurality of wide bandgap nitride semiconductor layers and a plurality of narrow bandgap nitride semiconductor layers, and the second super I lattice structure includes at least a wide bandgap nitride semiconductor layer and At least one narrow band gap nitride semiconductor layer is alternately stacked; and a transparent conductive layer is directly on one of the first lattice structure of the contact layer. 〃According to a preferred embodiment of the present invention, the material of the wide band gap object Γ conductor structure of the first superlattice structure is gallium nitride 'and the material of the first band gap nitride semiconductor layer of the first superlattice structure Is gallium nitride. In addition, the first supercrystalline I structure: see this gap lice compound semiconductor layer and narrow band gap nitride semiconductor. The material of the wide band gap nitride h bulk layer of the first super-day grid structure is gallium nitride, and the second The material of the narrow band-gap nitride semiconductor layer of the lattice structure is made of indium gallium, and the wide band-gap nitride semiconductor of the second superlattice structure is converted to & Office & ^ > The number of b-gap nitride semiconductor layers in the first month is between 1 and 2. s In the first and second embodiments of the present invention, the -superlattice structure is composed of s-4 lattice layer, where [the superlattice layer may be an aluminum gallium nitride layer / The gallium nitride layer / aluminum gallium nitride layer stacked lattice structure is composed of a second superlattice layer of t; the second superlattice layer may be a gallium nitride layer / indium gallium nitride layer / nitride Gallium layer stack structure. Since the first superlattice structure can disperse carriers and the second superlattice structure is available for carriers 载 ', the brightness of the light emitting element can be improved, and a stable low forward voltage can be obtained. [Embodiment] The present invention discloses a light-emitting element, which at least includes a contact made of a mixed superlattice structure, which can disperse 胄 hole carriers, and can provide carrier-through contact: and a transparent oxide layer can be directly deposited. Contact layer 1. Therefore, the redundancy of the hairy light element can be improved, and a stable and low forward voltage can be obtained. In order to make the description of the present invention more detailed and complete, reference may be made to the following description and the illustrations of FIG. 1 and FIG. 2. Mingxiang π Figure 1 'Figure 1 is a sectional view showing the structure of a light-emitting 7C element according to a preferred embodiment of the present invention. A light emitting device structure according to a preferred embodiment of the present invention may include a transparent substrate 100 sequentially stacked. A semi-V body layer 102, an active layer 104, a p-type cladding layer 106, a superlattice structure 108, a superlattice structure 10, and a transparent conductive layer 112. Among them, the superlattice structure 108 and the superlattice structure 110 constitute a contact layer, and the superlattice structure 108 and the superlattice structure 110 form a mixed superlattice structure. The material of the n-type semiconductor layer 102 may be, for example, n-type gallium nitride, and the material of the p-type confinement layer 106 may be, for example? The material of the nitrided type is transparent, and the material of the transparent conductive material 112 may be, for example, indium tin oxide. In addition, the superlattice structure 1⑽ may be composed of, for example, two to five pairs of alternately stacked wide-gap semiconductor material layers and narrow money + conductor material layers, wherein the wide-㈣ semiconductor material: half; the bulk material layer may be, for example, P Molybdenum nitride: (2) In this preferred embodiment, the material of the wide band gap semiconductor material layer of the superlattice structure 108 is hafnium nitride, and the material of the narrow semiconductor material layer of the superlattice structure ⑽ is nitrogen. Of course, the superlattice structure 108 may also be composed of one to three sets of a wide bandgap semiconductor material layer, a narrow bandgap semiconductor material layer, and a wide bandgap semiconductor material layer sequentially stacked. The material of the gap semiconductor material layer and the narrow band gap semiconductor material layer is, for example, a p-type doped nitride semiconductor, and the material of the upper and lower two wide band gap semiconductor material layers is preferably gallium nitride, and the middle narrow band gap semiconductor The material of the material layer is preferably gallium nitride. In addition, the thickness of the conductive material of the superlattice structure 108 is preferably less than 1 (A), and the thickness of the narrow band gap material layer of the superlattice structure 较佳 is preferably less than 500A.
由於超晶格結構108可散佈電洞載子，因此可提升發 光元件之亮度。 X 、一超θθ袼結構11 0可例如由一至二對交互堆疊之寬能 隙半導體材料層以及窄能隙半導體材料層所構成，其中寬 能隙半導體材料層與窄能隙半導體材料層之材質可例如 為Ρ型摻雜之氮化物半導體。在此較佳實施例中，超晶格 結構110之寬能隙半導體材料層的材料為氮化鎵，且超晶 秸、、α構11 〇之窄能隙半導體材料層的材料為氮化銦鎵。 =超甜格結構1 ! 0亦可由—至二組依序堆疊之寬能隙半 導體材料層、窄能隙半導體材料層、以及寬能隙半導體材 料θ所構成’其中上述之寬能隙半導體材料層與窄能隙半 595022 V體材枓層之材質可例如為p型 卜下系麻咖 4雜之鼠化物半導體，且 夕宠处饥、丄…* 何貝車父佳為氮化鎵，中間 乍此料導體材料層之材質較佳為氮化銦鎵。Since the superlattice structure 108 can disperse hole carriers, the brightness of the light emitting element can be improved. X, a super θθ 袼 structure 110 can be composed of, for example, one to two pairs of alternately stacked wide-gap semiconductor material layers and narrow-gap semiconductor material layers, wherein the materials of the wide-gap semiconductor material layer and the narrow-gap semiconductor material layer It may be, for example, a P-type doped nitride semiconductor. In this preferred embodiment, the material of the wide-gap semiconductor material layer of the superlattice structure 110 is gallium nitride, and the material of the super-crystalline, narrow-gap semiconductor material layer of the α-structure 110 is indium nitride. gallium. = Super-sweet lattice structure 1! 0 can also be composed of-two sets of a wide bandgap semiconductor material layer, a narrow bandgap semiconductor material layer, and a wide bandgap semiconductor material θ which are sequentially stacked. The material of the ply layer and the narrow band gap half 595022 V body material can be, for example, p-type sub-system maca 4 hybrid mouse compound semiconductor, and the pets are hungry and sloppy ... * He Beiche Jiajia is gallium nitride, The material of the conductive material layer in the middle is preferably indium gallium nitride.
料’超晶格結構11〇之寬能隙半導體材料層之厚度 較佳是小於1 〇〇A，而超晶格社I 料展夕「θ m ( 4、、。構110之窄能隙半導體材 料層之厚度較佳是小於500人。另外 四 力外，超晶格結構1 1 〇之 取上層較佳為寬能隙半導體材料 了曆且此取上層之寬能隙 半V體材料層的厚度較佳是小於5 〇 A。 由於超晶格結才冓110可供載子隨穿接觸，因此可設計 順向電壓差使其維持-定值，而可獲得低順向電壓。另 卜由於透明‘包112直接位於接觸層之超晶格結構 110上，即可與超晶格結構11〇形成良好之接觸，無須藉 助金屬媒介層或高摻雜濃度媒介層。因此，不會有媒介層 吸收輸出光的問題，也可將載子擴散限制住，而維持順向 電壓之穩定。 ' 請參照第2圖，第2圖係繪示依照本發明另一較佳實 施例的一種發光元件之結構剖面圖。本發明之另一較佳實 施例之發光元件結構可包括依序堆疊之透明之基板 200、p型半導體層202、主動層204、η型侷限層2〇6、 超晶格結構2 0 8、超晶袼結構2 1 〇、以及透明導電層2 12。 其中，超晶格結構208與超晶格結構2 1 0組成接觸層，且 超晶格結構208與超晶袼結構2 1 〇形成混合超晶袼結構。 ρ型半導體層202之材質可例如為ρ型氮化鎵，^型 侷限層206之材質可例如為η型氮化鎵，且透明導電層 2 12之材質可例如為氧化銦錫。相同地，超晶袼結構2〇8 11 595022 可例如由一至五對交互堆疊之寬能隙半導體材料層以及 :能隙半導體材料層所構成，亦可由二至三組依序堆疊之 寬能隙半導體材料層、窄能隙半導體材料層、以及寬=隙 半=體材料層所構成。在此實施例中，超晶格結構208 之見此隙半導體材料層與窄能隙半導體材料層之材質可 例如為η型氮化物半導體，且超晶格結構·之寬能隙半 導體材料層的材料為氮化銘鎵，超晶格結構之窄能隙 半導體材料層的材料為氮化鎵。此外，超晶格結構2〇8 · 之寬能隙半導體材料層之厚度較佳是小於1〇〇入，而超晶 格結構208 t窄能隙半導體材料層之厚度較佳是小於· 500A由於超晶格結構層208可散佈電洞載子，因此 提升發光元件之亮度。 另外，相同地，超晶格結構21〇可例如由一至二對交 互堆豐之寬能隙半導體材料層以及窄能隙半導體材料層 所構成，亦可由一至二組依序堆疊之寬能隙半導體材料 層、窄能隙半導體材料層、以及寬能隙半導體材料層所構 成在此貝施例中，1能隙半導體材料層與窄能隙半導體 材料層之材質可例如為4摻雜之氮化物半導體，且超晶 _ 格結構2Η)之寬能隙半導體材料層的材料為氮化錄，且= 曰^格結構210之窄能隙半導體材料層的材料為氮化銦 鎵。此外，超晶袼結構21〇之寬能隙半導體材料層之厚度 較佳是小於100Α ’而超晶格結構21G之窄能隙半導體材 料層之厚度較佳是小於500A。另外，超晶格結構21〇之 最上層較佳&寬能料導體材料層，且此最上層之寬能隙 半導體材料層的厚度較佳是小於5〇人。 此" 12 •由於，超晶格結構210可供載子隨穿接觸， 电層212直接位於超晶格結構210上，即可鱼赶曰 . 210 ^ ^ ^ '、超晶袼結構 /成良好之接觸，而無須藉助金屬媒介 声树人SL η 3 4円#雜？晨 將韵，會有媒介層吸收輸出光的問題，也可 、载子擴散限制住，進而可獲得低且穩定之順向電壓。 由上述本發明較佳實施例可知，本發明之一 1為本發明之發光元件之接觸層至少包括現合超晶^ ’且此混合超晶格結構之第__超晶格結構可散佈電洞載 子’因此可提升發光元件之亮度。 曰由上述本發明較佳實施例可知，本發明之另一優點就 疋因為本發明之發光元件之第二超晶格結構可供ρ型載 子或η型載子隨穿，且透明導電層可直接位於第二超晶格 結構上。因A ’可將載子擴散限制住，而獲得低且穩定之 順向電壓。 雖然本發明已以一較佳實施例揭露如上，然其並非用 以限定本發明，任何熟習此技#者，在不脫離本發明之精 神和範圍内，當可作各種之更動與潤錦，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】 第1圖係繪示依照本發明一較佳實施例的一種發光 元件之結構剖面圖。 第2圖係繪示依照本發明另一較佳實施例的一種發 光元件之結構剖面圖。 ^ 【元件代表符號簡單說明】 10 0 ·基板 13 595022 102 ： η型半導體層 104 ： 主動層 106 ： ρ型侷限層 108 ： 超晶格結構 110 ： 超晶格結構 112 ： 透明導電層 200 ： 基板 202 ： Ρ型半導體層 204 ： 主動層 206 ： η型半導體層 208 ： 超晶格結構 210 ： 超晶格結構 212 ： 透明導電層The thickness of the wide-gap semiconductor material layer of the super-lattice structure 11 is preferably less than 1000 A, and the super-lattice company I materials show that "θ m (4,... The thickness of the material layer is preferably less than 500 people. In addition to the four forces, the upper layer of the superlattice structure 1 1 10 is preferably a wide band gap semiconductor material, and the wide band gap half V-body material layer of the upper layer is taken. The thickness is preferably less than 50 Å. Since the superlattice junction 冓 110 is available for carriers to follow through, a forward voltage difference can be designed to maintain a constant value, and a low forward voltage can be obtained. Also because of transparency The package 112 is directly on the superlattice structure 110 of the contact layer, and can form a good contact with the superlattice structure 110, without the need of a metal medium layer or a highly doped concentration medium layer. Therefore, there is no absorption by the medium layer The problem of output light can also limit the carrier diffusion and maintain the forward voltage stability. 'Please refer to FIG. 2, which illustrates the structure of a light-emitting element according to another preferred embodiment of the present invention. Sectional view. Light emitting element junction of another preferred embodiment of the present invention It may include a sequentially stacked transparent substrate 200, a p-type semiconductor layer 202, an active layer 204, an n-type confinement layer 206, a superlattice structure 208, a supercrystalline osmium structure 2 1 0, and a transparent conductive layer 2 12. Among them, the superlattice structure 208 and the superlattice structure 210 constitute a contact layer, and the superlattice structure 208 and the supercrystalline osmium structure 2 10 form a mixed supercrystalline osmium structure. The material of the p-type semiconductor layer 202 may be For example, it is p-type gallium nitride, the material of the ^ -type confinement layer 206 may be, for example, n-type gallium nitride, and the material of the transparent conductive layer 2 12 may be, for example, indium tin oxide. Similarly, the supercrystalline rhenium structure 208 11 595022 can consist of, for example, one to five pairs of stacked wide bandgap semiconductor material layers and: bandgap semiconductor material layers, or two or three sets of sequentially stacked wide bandgap semiconductor material layers, narrow bandgap semiconductor material layers, And a wide = gap half = body material layer. In this embodiment, the material of the superlattice structure 208 and the narrow bandgap semiconductor material layer may be, for example, n-type nitride semiconductors, and the Lattice structure · Wide band gap semiconductor material layer The material is gallium nitride, and the material of the narrow bandgap semiconductor material layer of the superlattice structure is gallium nitride. In addition, the thickness of the wide bandgap semiconductor material layer of the superlattice structure 208 · is preferably less than 10%. The thickness of the 208 t narrow band gap semiconductor material layer of the superlattice structure is preferably less than 500 A. Since the superlattice structure layer 208 can disperse hole carriers, the brightness of the light emitting element is improved. In addition, the same, The superlattice structure 21 may be composed of, for example, one to two pairs of wide-gap semiconductor material layers and narrow-gap semiconductor material layers that are alternately stacked, or one or two sets of sequentially-stacked wide-gap semiconductor material layers and narrow-energy layers. Gap semiconductor material layer and wide band gap semiconductor material layer. In this example, the material of the 1 band gap semiconductor material layer and the narrow band gap semiconductor material layer may be, for example, a 4 doped nitride semiconductor, and the super crystal The material of the wide band gap semiconductor material layer of the lattice structure 2Η) is nitrided, and the material of the narrow band gap semiconductor material layer of the lattice structure 210 is indium gallium nitride. In addition, the thickness of the wide bandgap semiconductor material layer of the supercrystalline gadolinium structure 21 is preferably less than 100A 'and the thickness of the narrow bandgap semiconductor material layer of the superlattice structure 21G is preferably less than 500A. In addition, the uppermost layer of the superlattice structure 21 is preferably a & wide energy conductor material layer, and the thickness of the wide energy gap semiconductor material layer of the uppermost layer is preferably less than 50 people. This " 12 • Because the superlattice structure 210 is available for carriers to come in contact with each other, the electrical layer 212 is directly on the superlattice structure 210, that is to say, 210 ^ ^ ^ ', Good contact without the aid of metal media sound tree people SL η 3 4 円 # 杂? In the morning, there will be a problem that the medium layer absorbs the output light, and the carrier diffusion can be limited, so that a low and stable forward voltage can be obtained. It can be known from the above-mentioned preferred embodiments of the present invention that the first layer of the present invention 1 is a contact layer of the light-emitting element of the present invention including at least an in-situ supercrystal ^ ', and the hybrid superlattice structure of the __ superlattice structure can disperse electricity. The hole carrier 'can therefore increase the brightness of the light emitting element. It can be known from the above-mentioned preferred embodiments of the present invention that another advantage of the present invention is that the second superlattice structure of the light-emitting element of the present invention can be worn by p-type carriers or n-type carriers, and the transparent conductive layer It can be directly on the second superlattice structure. Because A 'can limit the carrier diffusion, a low and stable forward voltage is obtained. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Anyone who is familiar with this technique can make various modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of the appended patent application. [Brief description of the drawings] FIG. 1 is a cross-sectional view showing a structure of a light-emitting element according to a preferred embodiment of the present invention. Fig. 2 is a cross-sectional view showing a structure of a light emitting element according to another preferred embodiment of the present invention. ^ [Simple description of element representative symbols] 10 0 · Substrate 13 595022 102: n-type semiconductor layer 104: active layer 106: p-type confinement layer 108: superlattice structure 110: superlattice structure 112: transparent conductive layer 200: substrate 202: P-type semiconductor layer 204: Active layer 206: n-type semiconductor layer 208: Superlattice structure 210: Superlattice structure 212: Transparent conductive layer