1234891 九、發明說明： 【發明所屬之技術領域】 本發明係關於發光二極體之結構，特別係具有 低電阻的厚η型氮化鎵系接觸層之氮化鎵系發光二 極體結構。 — 【先前技術】 習知技藝氮化銦鎵/氮化鎵（InGaN/GaN)多量 子井結構（1111111:丨9113111；11111%^11，^1^^)發光二極體， 是利用η型氮化鎵（GaN)作為n型—接觸層 (Contacting layer)。但如果想利用高摻雜濃度 (n>lxl〇19Cnr3)的矽，製造低電阻的厚n型 = 觸層，在實際製造過程中發現，在氮化鎵層内部， 往往會因矽（Si)重摻雜的結果而導致易 ί;?;”象。此等現象’不僅影響氮化鎵2 /^質本纟且因為龜裂或甚至斷裂的現象，增加 ，其後一步驟，於其上方製作η型歐姆接觸電極声 。困^塑：f整體電特性變差或導電不良成為i °口:衫響所及，會必須增加整個元件的操 ?仵，巧時消耗之電功率增加，或是製造的良率 厚η型氮化鎵接觸層 =流產生使得整體二極體特性變差。因 前揭問題。 要種新的結構以解決 1234891 【發明内容】 1對前揭.習知技藝氮化鎵系、多量子井結構發光二極 =題’本發明，目的’係提供一種具有短週期超 B曰才σ數位接觸層之氮化鎵系發光二極體之結構。 本發明再一目的係於製造高摻雜濃度（n>lxl〇19cm_3) 且低電阻的厚Π型氮化鎵接觸層之同時，但不會發生習 知技藝於厚Π型氮化鎵層内，因為重摻雜矽而龜裂 ，斷裂現象，得以維持重摻雜氮化鎵接觸層之品質，其 猎由短週期重摻雜矽之氮化鋁鎵銦（n + + _Ah "GaxiWN) 成長超晶格結構，為具有短週期超晶格數位接觸層，以 :乍，免電阻值之n型接觸層（c〇ntacting於氮化 鎵/氮化鎵夕重里子井結構發光二極體（InGaN/GaN μ LEDs) ° 本發明又一目的係提供其後步驟，製作n型歐姆接 觸電極層的簡便性，並使得整體電特性變好，降低整體 兀件的操作電壓，其運作時消耗之電功率減低，及提高 生產良率。 土發，之目的及諸多優點將藉由下列具體實施例之 詳細5兒明’及參照所附圖示，而被完全揭露。 【實施方式】 —^ 一圖係根據本發明氮化鎵系發光二極體結構之第 一實施例。本發明氮化鎵系發光二極體結構的第一實施 例’其包含··基板11，雙重緩衝層（d〇uble buffer layer)12， n型氮化鎵（(^…層13，短週期超晶格數位 接觸層14,活性發光層15， p型被覆層16，及接觸層 17。 基板11的材質係氧化銘單晶（Sapphire)。位於基板 11上的雙重緩衝層12，其包含：第一緩衝層（first 1234891 buffer layer)121 與第二緩衝層（sec〇nd buffer layer)122。位於基板n上的第一缓衝層12卜材質係氮 化鋁鎵銦（Ah-x—yGaxInyN)，其中 〇$χ<1，〇gY<1。位於 第一緩衝層121上的第二緩衝層122，材質係氮化矽、 .(S i ^)。η型氮化鎵（(jaN )層13位於雙重緩衝層12上。 第二圖係根據本發明氮化鎵系發光二極體結構第一 實施例之短週期超晶格數位接觸層示意圖。位於η型氮 化鎵（GaN)層13上的短週期超晶格數位接觸層14，並包 含：位於η型氮化鎵（(^们層13上之複數個基礎層14\， 可重覆相疊，-般而言’其相疊個數不少於5。基礎層 141包含：第一基層1411與第二基層141^第一基層 14+1+1，其材質係矽（Si)重摻雜之η型氮化鋁鎵銦 (n -Alh—yGaxInj)，重摻雜濃度不小於每立方公 ls 個（n>lxl019cm-3)，且其中 〇$χ<1，〇$γ<1。第一基層 MU 的厚度"於5埃到50埃’成長溫度介於攝氏6〇〇度到 =〇度。位於第一基層H11上的第二基層⑷2,其材 質係氣化梦（SlN)。第二基層1412的厚度介於2埃到1〇 埃，成長溫度介於攝氏6〇〇度到12〇〇度。因此，第一美 m在n型氮化鎵(GaN)層13或經重覆相疊後二 位在第一基層1412上。 位於短週期超晶格數位接觸層14上的活性發光層 15，其材質係氮化銦鎵（InGaN)。位於活性發光層π曰上 被广，16 ’其材質係鎮推雜dd〇Ped)氮化銘鎵 钔（Ah-x-yGaxInyN) ’ 其中 〇$χ<1 ’ 〇$γ<1。位於 覆層16上的接觸層17，其材質係鎂摻雜 型氮化銘鎵銦⑴卜"GaxInyN)，其中βχ<，，心巧， 本發明氮化鎵系發光二極體結構的第一實施例，進 數18’其位於接觸層17或短週期超晶格 數位接觸層14上，且其可形成良好歐姆接觸。電極層18 1234891 包含 Ti/AL· Cr/Au，Cr/A卜 Cr/Pt/Au，Ti/Pt/Au，Cr/Pd/Au， Ti/Pd/Au，Ti/Al/Ti/Au， Ti/Al/Pt/Au，Ti/Al/Ni/Au， Ti/Al/Pd/Au，Ti/Al/Cr/Au，Ti/Al/Co/Au，Cr/Al/Cr/Au， Cr/Al/Pt/Au，Cr/Al/Pd/Au，Cr/Al/Ti/Au，Cr/Al/Co/Au， Cr/Al/Ni/Au，Pd/Al/Ti/Au，Pd/Al/Pt/Au，Pd/Al/Ni/Au， Pd/Al/Pd/Au，Pd/Al/Cr/Au，Pd/Al/Co/Au，Nd/Al/Pt/Au， Nd/Al/Ti/Au，Nd/Al/Ni/Au，Nd/Al/Cr/Au，Nd/Al/Co/Au， Hf/Al/Ti/Au，Hf/AI/Pt/Au，Hf/Al/Ni/Au，Hf/Al/Pd/Au， Hf/Al/Cr/Au，Hf/Al/Co/Au，Zr/Al/Ti/Au，Zr/Al/Pt/Au， Zr/Al/Ni/Au，Zr/Al/Pd/Au，Zr/Al/Cr/Au，Zr/Al/Co/Au， TiNx/Ti/Au，TiNx/Pt/Au，TiNx/Ni/Au，TiNx/Pd/Au， TiNx/Cr/Au，TiNx/Co/Au，TiWNx/Ti/Au，TiWNx/Pt/Au， TiWNx/Ni/Au，TiWNx/Pd/Au，TiWNx/Cr/Au， TiWNx/Co/Au，NiAl/Pt/Au，NiAl/Cr/Au，NiAl/Ni/Au， NiAl/Ti/Au，Ti/NiAl/Pt/Au，Ti/NiAl/Ti/Au， Ti/NiAl/Ni/Au，Ti/NiAl/Cr/Au，或任何其他上述材料形 成之化合物。 第三圖係根據本發明氮化鎵系發光二極體結構之第 二實施例。本發明氮化鎵系發光二極體結構的第二實施 例，其包含：基板21，雙重緩衝層（double buffer layer)22，η型氮化鎵（GaN)層23，短週期超晶格數位接 觸層24，活性發光層25，p型被覆層26，及接觸層27。 基板21之材質係氧化鋁單晶（Sapphire)。位於基板 21上的雙重缓衝層（double buff er layer) 22，包含：第 一缓衝層（first buffer layer)221與第二缓衝層 (second buffer layer)222。位於基板 21 上的第一缓 衝層（first buffer layer)221，其材質係氮化紹鎵銦 (Ali-x-yGaxInyN)，其中 0SX<1，0$ Y<1。位於第一缓衝 層 221 的第二緩衝層（second buffer layer)222，其 1234891 材質係氮化矽（SiN)。η型氮化鎵（GaN)層23，係位於訾 重缓衝層22上。 ' 第四圖係根據本發明氮化鎵系發光二極體結構第二 實，例之短週期超晶格數位接觸層示意圖。位於 化鎵（GaN)層23上之短週期超晶格數位接觸層24，包 含··位於η型氮化鎵（GaN)層23上之複數個基礎層24〇。 基礎層240可重覆相疊，一般而言，其相疊個數不少於 5:基礎層240包含：第一基層2401，與第二基層24〇2。 第:基層2401，其材質係矽（Si)重摻雜n型氮化鋁鎵銦 (n -AlityGaxInyN)，其中 〇$χ<ι，〇$γ<ι。第一基層 24〇1 的重摻雜濃度不小於每立方公分1〇!9個（n>lxl〇19cm_3)。 第一基層2401的厚度介於5埃到5〇埃。第一基層24〇1 的成長溫度介於攝氏600度到1200度。 曰 位於第一基層2401上之第二基層2402,其材質係未 摻雜（undoped)氮化銦鎵（iniLGauN)，其中u q。第二 基層2402的厚度介於5埃到50埃。第二基層24〇2的成 長溫度介於攝氏600度到1 200度。第一基層24〇1可位 在η型氮化鎵（GaN)層23上，或經重覆相疊後，位在签 二基層2402上。 位於短週期超晶格數位接觸層24上活性發光層 25，其材質係氮化銦鎵（inGaN)。 曰 =於活性發光層25上之p型被覆層26，兵材質係鎂摻雜 (Mg - doped)氮化鋁鎵銦（Alh-yGaxInyN)，其中 〇$χ〈卜 〇$Υ<1。位於p型被覆層26上之接觸層其^質係鎬 摻雜（Mg-doped) p型氮化鋁鎵銦（All_x_yGaxIny 豆、 OgXd，〇$ Yd。 本發明氮化鎵系發光二極體結構的第二實施例，達 一步地包含電極層28,其可位於接觸層27或短週期超曰E 格數位接觸層24上，且其可形成良好歐姆接觸。電極^ 1234891 28 包含 Ti/Al，Cr/Au，Cr/A卜 Cr/Pt/Au，Ti/Pt/Au， Cr/Pd/Au，Ti/Pd/Au，Ti/Al/Ti/Au，Ti/Al/Pt/Au， Ti/Al/Ni/Au，Ti/Al/Pd/Au，Ti/Al/Cr/Au，Ti/Al/Co/Au， Cr/Al/Cr/Au，Cr/Al/Pt/Au，Cr/Al/Pd/Au，Cr/Al/Ti/Au， Cr/Al/Co/Au，Cr/Al/Ni/Au，Pd/Al/Ti/Au，Pd/Al/Pt/Au， Pd/Al/Ni/Au，Pd/Al/Pd/Au，Pd/Al/Cr/Au，Pd/Al/Co/Au， Nd/Al/Pt/Au，Nd/Al/Ti/Au，Nd/Al/Ni/Au，Nd/Al/Cr/Au， Nd/Al/Co/Au，Hf/Al/Ti/Au，Hf/AI/Pt/Au，Hf/Al/Ni/Au， Hf/Al/Pd/Au，Hf/Al/Cr/Au，Hf/Al/Co/Au，Zr/Al/Ti/Au， Zr/Al/Pt/Au，Zr/Al/Ni/Au，Zr/Al/Pd/Au，Zr/Al/Cr/Au， Zr/Al/Co/Au，TiNx/Ti/Au，TiNx/Pt/Au， TiNx/Ni/Au， TiNx/Pd/Au，TiNx/Cr/Au，TiNx/Co/Au，TiWNx/Ti/Au， TiWNx/Pt/Au，TiWNx/Ni/Au，TiWNx/Pd/Au， TiWNx/Cr/Au，TiWNx/Co/Au，NiAl/Pt/Au，NiAl/Cr/Au， NiAl/Ni/Au，NiAl/Ti/Au，Ti/NiAl/Pt/Au，Ti/NiAl/Ti/Au， Ti/NiAl/Ni/Au，Ti/NiAl/Cr/Au，或任何其他上述材料形 成之化合物。 本文以上所述僅為本發明之較佳實施例而已，並非 用以限定本發明之申請專利範圍，任何其它凡不脫離本 發明所揭示精神而完成的改變或修飾，均應屬本發明之 申請專利範圍。 【圖式簡單說明】 第一圖係根據本發明氮化鎵系發光二極體結構之第 一實施例。 第二圖係根據本發明氮化鎵系發光二極體結構第一 實施例之短週期超晶格數位接觸層示意圖。 第三圖係根據本發明氮化鎵系發光二極體結構之第 二實施例。 1234891 第四圖係根據本發明氮化鎵系發光二極體結構第二 實施例之短週期超晶格數位接觸層示意圖。 【主要元件符號說明】 11 基板 12 雙重緩衝層 121 第一緩衝層 122 第二缓衝層1234891 IX. Description of the invention: [Technical field to which the invention belongs] The present invention relates to the structure of a light emitting diode, and particularly to a gallium nitride based light emitting diode structure having a low-resistance thick n-type gallium nitride based contact layer. — [Prior art] Known technology InGaN / GaN multi-quantum well structure (1111111: 丨 91113111; 11111% ^ 11, ^ 1 ^^) light-emitting diode, which uses η-type Gallium nitride (GaN) is used as an n-type-contacting layer. However, if you want to use silicon with a high doping concentration (n > lx1019Cnr3) to produce a low-resistance thick n-type contact layer, it is found in the actual manufacturing process that the silicon nitride (Si) is often caused by silicon (Si) in the gallium nitride layer. As a result of the heavy doping, it is easy to make "?"; Such phenomena. These phenomena 'not only affect the quality of gallium nitride 2 / ^, but also increase due to cracking or even fracture, the next step, above it Making η-type ohmic contact electrode sound. Sleepy plastic: f the overall electrical characteristics become worse or poor conductivity becomes i ° mouth: as far as the shirt is concerned, it will have to increase the operation of the entire component, the electrical power consumed by coincidence will increase, or The manufacturing yield of thick η-type GaN contact layer = current generation makes the overall diode characteristics worse. Because of the problem of the previous disclosure. A new structure is needed to solve 1234891 [Summary of the invention] 1 pair of previous disclosure. Known technology nitrogen A gallium-based, multi-quantum-well structure light-emitting diode = titled "Invention, Purpose" is to provide a structure of a gallium nitride-based light-emitting diode with a short-period super-b σ digital contact layer. Another object of the present invention Based on manufacturing high doping concentration (n > lxl019cm_3) and low resistance At the same time as the gallium nitride contact layer, the conventional technique does not occur in the thick Π-type gallium nitride layer. The phenomenon of cracking and fracture due to heavily doped silicon can maintain the quality of the heavily doped gallium nitride contact layer. It hunts short-period heavily doped silicon aluminum gallium indium (n + + _Ah " GaxiWN) to grow a superlattice structure. It is a digital contact layer with a short-period superlattice. Type contact layer (conntacting on gallium nitride / gallium nitride burial structure light-emitting diodes (InGaN / GaN μ LEDs) ° Another object of the present invention is to provide a subsequent step to fabricate an n-type ohmic contact electrode layer Simplicity, and make the overall electrical characteristics better, reduce the operating voltage of the overall components, reduce the power consumed during operation, and improve production yield. The purpose and many advantages of the land development will be achieved by the following specific embodiments The details are described in detail below and with reference to the accompanying drawings, and are fully disclosed. [Embodiment] — ^ A figure is a first embodiment of a gallium nitride based light emitting diode structure according to the present invention. The gallium nitride based First embodiment of a light-emitting diode structure ·· Substrate 11, double buffer layer 12, n-type gallium nitride ((^ ... layer 13, short-period superlattice digital contact layer 14, active light-emitting layer 15, p-type cladding layer 16, And contact layer 17. The material of the substrate 11 is Sapphire. The double buffer layer 12 on the substrate 11 includes: a first 1234891 buffer layer 121 and a second buffer layer (sec. nd buffer layer) 122. The first buffer layer 12 on the substrate n is made of aluminum gallium indium nitride (Ah-x-yGaxInyN), where 〇 $ χ < 1, 〇gY < 1. The second buffer layer 122 located on the first buffer layer 121 is made of silicon nitride, (S i ^). An n-type gallium nitride (jaN) layer 13 is located on the double buffer layer 12. The second figure is a schematic diagram of a short-period superlattice digital contact layer according to the first embodiment of the gallium nitride-based light emitting diode structure according to the present invention. The short-period superlattice digital contact layer 14 on the n-type gallium nitride (GaN) layer 13 includes: a plurality of base layers 14 on the n-type gallium nitride (three layers 13), which can repeat the phase Stacked,-generally 'the number of overlapping is not less than 5. The base layer 141 includes: a first base layer 1411 and a second base layer 141 ^ the first base layer 14 + 1 + 1, and its material is silicon (Si) re-doped The hetero-n-type aluminum gallium indium nitride (n-Alh-yGaxInj) has a heavy doping concentration of not less than ls per cubic cubic (n > lxl019cm-3), and among them, 〇 $ χ < 1, 〇 $ γ < 1. The thickness of the first base layer MU is between 5 angstroms and 50 angstroms. The growth temperature is between 600 degrees Celsius and 0 degrees Celsius. The second base layer ⑷2 on the first base layer H11 is made of a gasification dream (SlN). The thickness of the second base layer 1412 is between 2 angstroms and 10 angstroms, and the growth temperature is between 600 degrees and 12,000 degrees Celsius. Therefore, the first beautiful layer 14 is formed in the n-type gallium nitride (GaN) layer 13 or After overlapping On the first base layer 1412. The active light-emitting layer 15 on the short-period superlattice digital contact layer 14 is made of indium gallium nitride (InGaN). It is located on the active light-emitting layer π, and its material is 16 Doped with dd〇Ped) Gallium nitride gallium nitride (Ah-x-yGaxInyN) 'Among them 〇 $ χ < 1' 〇 $ γ < 1. The contact layer 17 on the cladding layer 16 is made of magnesium-doped nitrogen GaInInN (GaXInyN), where βχ < ,, is ingenious, the first embodiment of the gallium nitride-based light emitting diode structure of the present invention is advanced to 18 ′, which is located in the contact layer 17 or a short-period supercrystal The grid digital contact layer 14 can form a good ohmic contact. The electrode layer 18 1234891 contains Ti / AL · Cr / Au, Cr / A and Cr / Pt / Au, Ti / Pt / Au, Cr / Pd / Au, Ti / Pd / Au, Ti / Al / Ti / Au, Ti / Al / Pt / Au, Ti / Al / Ni / Au, Ti / Al / Pd / Au, Ti / Al / Cr / Au, Ti / Al / Co / Au, Cr / Al / Cr / Au, Cr / Al / Pt / Au, Cr / Al / Pd / Au, Cr / Al / Ti / Au, Cr / Al / Co / Au, Cr / Al / Ni / Au, Pd / Al / Ti / Au, Pd / Al / Pt / Au, Pd / Al / Ni / Au, Pd / Al / Pd / Au, Pd / Al / Cr / Au, Pd / Al / Co / Au, Nd / Al / Pt / Au, Nd / Al / Ti / Au, Nd / Al / Ni / Au, Nd / Al / Cr / Au, Nd / Al / C o / Au, Hf / Al / Ti / Au, Hf / AI / Pt / Au, Hf / Al / Ni / Au, Hf / Al / Pd / Au, Hf / Al / Cr / Au, Hf / Al / Co / Au, Zr / Al / Ti / Au, Zr / Al / Pt / Au, Zr / Al / Ni / Au, Zr / Al / Pd / Au, Zr / Al / Cr / Au, Zr / Al / Co / Au, TiNx / Ti / Au, TiNx / Pt / Au, TiNx / Ni / Au, TiNx / Pd / Au, TiNx / Cr / Au, TiNx / Co / Au, TiWNx / Ti / Au, TiWNx / Pt / Au, TiWNx / Ni / Au, TiWNx / Pd / Au, TiWNx / Cr / Au, TiWNx / Co / Au, NiAl / Pt / Au, NiAl / Cr / Au, NiAl / Ni / Au, NiAl / Ti / Au, Ti / NiAl / Pt / Au, Ti / NiAl / Ti / Au, Ti / NiAl / Ni / Au, Ti / NiAl / Cr / Au, or any other compound of these materials. The third figure is a second embodiment of a GaN-based light emitting diode structure according to the present invention. The second embodiment of the gallium nitride-based light emitting diode structure of the present invention includes a substrate 21, a double buffer layer 22, an n-type gallium nitride (GaN) layer 23, and a short-period superlattice digit. The contact layer 24, the active light emitting layer 25, the p-type coating layer 26, and the contact layer 27. The material of the substrate 21 is an alumina single crystal (Sapphire). The double buffer layer 22 on the substrate 21 includes a first buffer layer 221 and a second buffer layer 222. A first buffer layer 221 on the substrate 21 is made of indium gallium indium nitride (Ali-x-yGaxInyN), where 0SX < 1, 0 $ Y < 1. A second buffer layer 222 located on the first buffer layer 221 is made of 1234891 silicon nitride (SiN). The n-type gallium nitride (GaN) layer 23 is located on the heavy buffer layer 22. 'The fourth figure is a schematic view of a short-period superlattice digital contact layer according to the second embodiment of the gallium nitride-based light emitting diode structure according to the present invention. The short-period superlattice digital contact layer 24 on the gallium nitride (GaN) layer 23 includes a plurality of base layers 24 on the n-type gallium nitride (GaN) layer 23. The base layer 240 may overlap each other. Generally, the number of the base layer 240 is not less than 5: The base layer 240 includes: a first base layer 2401 and a second base layer 2402. First: the base layer 2401, whose material is silicon (Si) heavily doped n-type aluminum gallium indium nitride (n-AlityGaxInyN), where 〇 $ χ < ι, 〇 $ γ < ι. The heavily doped concentration of the first base layer 2401 is not less than 100.9 cm3 (n > lx1019cm_3). The thickness of the first base layer 2401 is between 5 angstroms and 50 angstroms. The growth temperature of the first base layer 2401 is between 600 ° C and 1200 ° C. The second base layer 2402 on the first base layer 2401 is made of undoped indium gallium nitride (iniLGauN), where u q. The thickness of the second base layer 2402 is between 5 and 50 angstroms. The second substrate layer 2402 has a growth temperature between 600 ° C and 1200 ° C. The first base layer 2401 may be located on the n-type gallium nitride (GaN) layer 23, or may be located on the second base layer 2402 after overlapping and overlapping. The active light emitting layer 25 located on the short-period superlattice digital contact layer 24 is made of indium gallium nitride (inGaN). = = P-type coating layer 26 on the active light-emitting layer 25. The material is magnesium-doped (Mg-doped) aluminum gallium indium nitride (Alh-yGaxInyN), of which 〇 $ χ 〈卜 〇 $ Υ < 1. The contact layer on the p-type cladding layer 26 has a Mg-doped p-type aluminum gallium indium nitride (All_x_yGaxIny bean, OgXd, 0 $ Yd.) The gallium nitride-based light emitting diode structure of the present invention The second embodiment of the invention further includes an electrode layer 28, which can be located on the contact layer 27 or the short-period E-grid digital contact layer 24, and which can form a good ohmic contact. The electrode ^ 1234891 28 includes Ti / Al, Cr / Au, Cr / A, Cr / Pt / Au, Ti / Pt / Au, Cr / Pd / Au, Ti / Pd / Au, Ti / Al / Ti / Au, Ti / Al / Pt / Au, Ti / Al / Ni / Au, Ti / Al / Pd / Au, Ti / Al / Cr / Au, Ti / Al / Co / Au, Cr / Al / Cr / Au, Cr / Al / Pt / Au, Cr / Al / Pd / Au, Cr / Al / Ti / Au, Cr / Al / Co / Au, Cr / Al / Ni / Au, Pd / Al / Ti / Au, Pd / Al / Pt / Au, Pd / Al / Ni / Au, Pd / Al / Pd / Au, Pd / Al / Cr / Au, Pd / Al / Co / Au, Nd / Al / Pt / Au, Nd / Al / Ti / Au, Nd / Al / Ni / Au, Nd / Al / Cr / Au, Nd / Al / Co / Au, Hf / Al / Ti / Au, Hf / AI / Pt / Au, Hf / Al / Ni / Au, Hf / Al / Pd / Au, Hf / Al / Cr / Au, Hf / Al / Co / Au, Zr / Al / Ti / Au, Zr / Al / Pt / Au, Zr / Al / Ni / Au, Zr / Al / Pd / Au, Zr / Al / Cr / Au, Zr / Al / Co / Au, TiNx / Ti / Au, TiNx / Pt / Au, TiNx / Ni / Au, TiNx / Pd / Au, TiNx / Cr / Au, TiNx / Co / Au , TiWNx / Ti / Au, TiWNx / Pt / Au, TiWNx / Ni / Au, TiWNx / Pd / Au, TiWNx / Cr / Au, TiWNx / Co / Au, NiAl / Pt / Au, NiAl / Cr / Au, NiAl / Ni / Au, NiAl / Ti / Au, Ti / NiAl / Pt / Au, Ti / NiAl / Ti / Au, Ti / NiAl / Ni / Au, Ti / NiAl / Cr / Au, or any of the above materials The compounds described above are only the preferred embodiments of the present invention, and are not intended to limit the scope of patent application of the present invention. Any other changes or modifications made without departing from the spirit disclosed by the present invention shall belong to the present invention. The scope of patent application. [Brief description of the drawings] The first diagram is a first embodiment of a gallium nitride-based light emitting diode structure according to the present invention. The second figure is a schematic diagram of a short-period superlattice digital contact layer according to the first embodiment of the gallium nitride-based light emitting diode structure according to the present invention. The third figure is a second embodiment of a GaN-based light emitting diode structure according to the present invention. 1234891 The fourth diagram is a schematic diagram of a short-period superlattice digital contact layer according to the second embodiment of the gallium nitride-based light emitting diode structure according to the present invention. [Description of main component symbols] 11 Substrate 12 Double buffer layer 121 First buffer layer 122 Second buffer layer
13 η型氮化鎵層 14 短週期超晶格數位接觸層 141 基礎層 1411 第一基層 1412 第二基層 15 活性發光層 16 ρ型被覆層 17 接觸層 18 電極層 21 基板13 η-type gallium nitride layer 14 Short-period superlattice digital contact layer 141 Base layer 1411 First base layer 1412 Second base layer 15 Active light emitting layer 16 R-type coating layer 17 Contact layer 18 Electrode layer 21 Substrate
22 雙重緩衝層 221 第一緩衝層 222 第二緩衝層 23 η型氮化鎵層 24 短週期超晶格數位接觸層 240 基礎層 2401 第一基層 2402 第二基層 25 活性發光層 26 ρ型被覆層 11 1234891 27 28 接觸層 電極層22 double buffer layer 221 first buffer layer 222 second buffer layer 23 n-type gallium nitride layer 24 short-period superlattice digital contact layer 240 base layer 2401 first base layer 2402 second base layer 25 active light emitting layer 26 p-type coating layer 11 1234891 27 28 Contact layer electrode layer