201133934 六 [0001] [0002] Ο [0003] ❹ [0004] [0005] 099109645 發明說明： 【發明所屬之技術領域】 本發明涉及一種發光二極體，尤其涉及散熱性能較好的 發光二極體。本發明還提供了一種該發光二極體的製作 方法。 [先前技術3 發光二極體（Light Emitting Diode，LED)是一種可 將電流轉換成特定波長範圍的光的半導體元件。發光_ 極體以其亮度高、工作電壓低、功耗小、易與積體電路 匹配、驅動簡單 ' 壽命長等優點，從而可作為光源而廣 泛應用於照明領域。 ； LED通常包括p型半導體層、活性層及n型半導體層在 LED兩端施加電壓’空穴與電子將會在活性層複合，轄射 出光子。LED在應用過程中所面臨的一個問題是其散熱問 題。若LED在工作過程中所產生的熱量不能有效地散發， 將會影響LED的發光效率。 【發明内容】 有鐾於此’有必要提供—種散熱性能較好的發光二極體 〇 一種發光一極體’其包括一透明基板及在透明基板形成 的多個發光結構單元。每個發光結構單元包括依次層疊 的N型半導體層、多量子井活性層、p型半導體層。p型半 導體層表面設置有P型接觸電極，N型半導體層表面設置 有N型接觸電極。該發光結構單元進一步包括一凹陷部， 該凹陷部從P型半導體層延伸到N型半導體層 。該凹陷部 表單編號A0101 第3頁/共19頁 0992017089-0 201133934 内填充有金屬材料，且該金屬材料延伸至覆蓋發光結構 單元的表面。該金屬材料分為相互絕緣的兩部分，形成 多個發光結構單元共同進行對外連接的兩個電極。 [0006] [0007] [0008] [0009] [0010] [0011] 099109645 一種發光二極體的製作方法，其包括以下步驟： 提供一個透明基板，在透明基板上依次沈積N型半導體層 、活性層及P型半導體層以形成一發光結構； 在發光結構之間形成隔離槽得到多個發光結構單元，同 時在發光結構單元中製作凹陷部，該凹陷部從P型半導體 層延伸到N型半導體層，顯露出N型半導體層的表面； 在每個發光結構單元的P型半導體層表面與N型半導體層 表面分別製作P型接觸電極與N型接觸電極，然後製作第 一絕緣層，該第一絕緣層完全覆蓋除P型接觸電極與N型 接觸電極以外的區域，然後製作金屬電連接層將多個發 光結構單元之間電性連接； 在金屬電連接層表面製作第二絕緣層，然後在凹陷部内 填入金屬材料，且金屬材料延伸至覆蓋發光結構表面， 該金屬材料分為相互絕緣的兩部分，形成多個發光結構 單元共同進行對外連接的兩個電極。 相較於先前技術，本發明藉由在發光二極體的凹陷部内 填充金屬材料，由於金屬材料的導熱性能較好，且金屬 材料靠近發光結構的發光層設置，發光二極體發光層的 熱量可以有效傳遞到金屬材料中，有利於發光二極體的 散熱。 【實施方式】 表單編號A0101 第4頁/共19頁 0992017089-0 201133934 [0012] [0013] 下面以具體的實施例對本發明作進一步地說明。 請參見圖1，本發明實施例所提供的發光二極體1〇〇包括 一個透明基板11及兩個發光結構單元丨2 «該透明基板η 可為藍寶石透明基板（sapphire)或是二氧化發基板。 每個發光結構單元12包括在透明基板丨丨上依次層疊的尺型 GaN層121，第一多量子井活性層122，第二多量子井活 性層123 ’ P型GaN層124，在卩型(^層124與j^GaN層 121表面分別設置有P型接觸電極丨25與N型接觸電極126 Ο [0014] 根據需要’所述P型GaN層124與N型GaN層121亦可以用其 他半導體材料替代，如氮化鋁鎵（AlGaN)、氮化銦鎵（ InGaN)、氮化鋁鎵銦（AlGalnN)、磷化鎵（GaP)、 砷化鎵（GaAs)等。 [0015] ❸ 所述多量子井活性層由相互堆疊的第一種111^族氮化鋁 銦鎵（AlxInyGai_x_yN)層與第二種iu_v族氮化鋁鎵銦 (A1uGavIrVu-vl)麕所構成，其中&XS1，0$y< 1’ x + ySl 以及 0<US1，0SV<1，11切$1且3^11，y 竽v。可依需求調整金屬元素之間的參數獲得所需的發光 波長。在本實施例中，發光二極體1〇〇的第一多量子井活 性層122與第二多量子井活性層123相互層叠。所述第一 多量子井活性層122與第二多量子井活性層123可以發出 相同波長的光線，亦可以發出不同波長的光線。在本實 施例中’所述第一多量子井活性層122與第二多量子井活 性層123所發出的光線的波長在38〇11111至6〇〇11111的範圍内 099109645 。根據需要’亦可以只有一個多量子井活性層 表單編號A0101 第5頁/共19頁 0992017089-0 201133934 [0016] [0017] 發光結構單兀12具有一凹陷部13。該凹陷部13從15型(^~ 層124延伸到N型GaN層121，從而顯露出1^型(^!^層121的 表面，用於在N型GaN層121的表面製作N型接觸電極ΐ2β 。該多個發光結構單元丨2進一步包括隔離槽19，避免發 光二極體100在工作時發光結構單元12之間產生電性干擾 而造成發光結構單元12之間的短路現象。 為實現兩個發光結構單元12之間的電連接，該發光二極 體100還進一步包括一電連接層14。該電連接層14可以根 據兩個發光結構單元12之間的電連接關係如串聯或是並 聯或是串並聯的方式而按需要製作，若發光結構單元i 2 足夠時，發光結構單元12亦可以形成串聯與並聯結合的 方式。在本實施例中，該電连接層14將其中一個發光結 構單元12的N型接觸電極126與另外一個發光結構單元12 的P型接觸電極125相連接，從而使兩個發光結構單元12 之間形成串聯連接的關係。另外，亦可以藉由改變電連 接層14的設置，從而使兩個發光結構單元12之間形成並 聯連接的關係。該電連接層14可以藉由真空蒸鍍的方法 製作在發光結構單元12的表面。為了避免該電連接層14 附著在發光結構單元1 2的各層的侧面而造成短路，可以 事先在發光結構單元12的表面設置一層第一絕緣層15。 該第一絕緣層15完全覆蓋除P型接觸電極125與N型接觸電 極126以外的區域。該第一絕緣層15可以是二氧化石夕（[0003] [0003] [0003] 0003 [0003] [0004] [0005] 00005109645 Description of the Invention: [Technical Field] The present invention relates to a light-emitting diode, and more particularly to a light-emitting diode having better heat dissipation performance . The invention also provides a method of fabricating the light emitting diode. [Prior Art 3 A Light Emitting Diode (LED) is a semiconductor element that converts a current into light of a specific wavelength range. The illuminating _ polar body is widely used in the field of illumination because of its high brightness, low operating voltage, low power consumption, easy matching with integrated circuits, and simple driving life. LEDs typically include a p-type semiconductor layer, an active layer, and an n-type semiconductor layer that apply a voltage across the LED. Holes and electrons will recombine in the active layer, modulating the photons. One of the problems LEDs face in the application process is their thermal issues. If the heat generated by the LED during operation cannot be effectively dissipated, it will affect the luminous efficiency of the LED. SUMMARY OF THE INVENTION It is necessary to provide a light-emitting diode having a good heat dissipation performance. A light-emitting body includes a transparent substrate and a plurality of light-emitting structural units formed on the transparent substrate. Each of the light-emitting structural units includes an N-type semiconductor layer, a multi-quantum well active layer, and a p-type semiconductor layer which are sequentially stacked. The surface of the p-type semiconductor layer is provided with a P-type contact electrode, and the surface of the N-type semiconductor layer is provided with an N-type contact electrode. The light emitting structure unit further includes a depressed portion extending from the P-type semiconductor layer to the N-type semiconductor layer. The recessed portion Form No. A0101 Page 3 of 19 0992017089-0 201133934 is filled with a metallic material that extends to cover the surface of the light-emitting structural unit. The metal material is divided into two parts which are insulated from each other, and two electrodes which are connected to each other by a plurality of light-emitting structural units are formed. [0006] [0009] [0011] [0011] 099109645 A method for fabricating a light-emitting diode, comprising the steps of: providing a transparent substrate, sequentially depositing an N-type semiconductor layer on the transparent substrate, and active a layer and a P-type semiconductor layer to form a light-emitting structure; forming an isolation trench between the light-emitting structures to obtain a plurality of light-emitting structure units, and simultaneously forming a recess portion in the light-emitting structure unit, the recess portion extending from the P-type semiconductor layer to the N-type semiconductor a layer exposing a surface of the N-type semiconductor layer; forming a P-type contact electrode and an N-type contact electrode on the surface of the P-type semiconductor layer of each of the light-emitting structural units and the surface of the N-type semiconductor layer, and then forming a first insulating layer, the first An insulating layer completely covers a region other than the P-type contact electrode and the N-type contact electrode, and then a metal electrical connection layer is formed to electrically connect the plurality of light-emitting structural units; a second insulating layer is formed on the surface of the metal electrical connection layer, and then The metal material is filled in the concave portion, and the metal material extends to cover the surface of the light emitting structure, and the metal material is divided into two parts insulated from each other to form a plurality of hairs. The optical structure unit collectively performs two electrodes connected externally. Compared with the prior art, the present invention fills the metal material in the depressed portion of the light-emitting diode. Since the heat conductive property of the metal material is good, and the metal material is disposed near the light-emitting layer of the light-emitting structure, the heat of the light-emitting diode light-emitting layer is compared. It can be effectively transferred to the metal material, which is beneficial to the heat dissipation of the light-emitting diode. [Embodiment] Form No. A0101 Page 4 of 19 0992017089-0 201133934 [0013] The present invention will be further described below by way of specific examples. Referring to FIG. 1 , a light-emitting diode 1 本 according to an embodiment of the invention includes a transparent substrate 11 and two light-emitting structural units « 2 « The transparent substrate η can be a sapphire transparent substrate or a oxidized hair Substrate. Each of the light emitting structure units 12 includes a ruled GaN layer 121 sequentially stacked on a transparent substrate, a first multi-quantum well active layer 122, and a second multi-quantum well active layer 123' P-type GaN layer 124. The surface of the layer 124 and the GaN layer 121 are respectively provided with a P-type contact electrode 丨25 and an N-type contact electrode 126. [0014] The P-type GaN layer 124 and the N-type GaN layer 121 may also be made of other semiconductors as needed. Substituting materials such as aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), aluminum gallium indium nitride (AlGalnN), gallium phosphide (GaP), gallium arsenide (GaAs), etc. [0015] The multi-quantum well active layer is composed of a first group 111Mn aluminum indium gallium nitride (AlxInyGai_x_yN) layer and a second iu_v aluminum aluminum gallium indium (A1uGavIrVu-vl) layer, wherein &XS1,0 $y< 1' x + ySl and 0 <US1,0SV<1,11 cut $1 and 3^11,y 竽v. The parameters between the metal elements can be adjusted as needed to obtain the desired illuminating wavelength. In this embodiment The first multi-quantum well active layer 122 and the second multi-quantum well active layer 123 of the light-emitting diode 1 are stacked on each other. The first multi-quantum well activity 122 and the second multi-quantum well active layer 123 can emit light of the same wavelength, and can also emit light of different wavelengths. In the embodiment, the first multi-quantum well active layer 122 and the second multi-quantum well active layer 123 The wavelength of the emitted light is in the range of 38〇11111 to 6〇〇11111 099109645. As needed, there may be only one multi-quantum well active layer form number A0101 Page 5 / 19 pages 0992017089-0 201133934 [0016] [ The light-emitting structure unit 12 has a recessed portion 13. The recessed portion 13 extends from the 15 type (^~ layer 124 to the N-type GaN layer 121, thereby exposing the surface of the layer 1 (for the surface layer 121) An N-type contact electrode ΐ2β is formed on the surface of the N-type GaN layer 121. The plurality of light-emitting structure units 丨2 further include isolation trenches 19 to prevent electrical interference between the light-emitting diode units 100 during operation. Short circuit phenomenon between the light emitting structure units 12. In order to realize electrical connection between the two light emitting structure units 12, the light emitting diode 100 further includes an electrical connection layer 14. The electrical connection layer 14 may be according to two light emitting structures. Between units 12 The connection relationship is made as needed in series or in parallel or in series and parallel mode. If the light-emitting structure unit i 2 is sufficient, the light-emitting structure unit 12 can also be formed in series and parallel connection. In this embodiment, the electrical connection The layer 14 connects the N-type contact electrode 126 of one of the light-emitting structure units 12 to the P-type contact electrode 125 of the other of the light-emitting structure units 12, thereby forming a series connection relationship between the two light-emitting structure units 12. Alternatively, the relationship between the two light-emitting structural units 12 can be formed in a parallel connection by changing the arrangement of the electrical connection layer 14. The electrical connection layer 14 can be formed on the surface of the light-emitting structural unit 12 by vacuum evaporation. In order to prevent the electrical connection layer 14 from being attached to the side faces of the respective layers of the light-emitting structural unit 12, a short circuit may be provided, and a first insulating layer 15 may be provided on the surface of the light-emitting structural unit 12 in advance. The first insulating layer 15 completely covers a region other than the P-type contact electrode 125 and the N-type contact electrode 126. The first insulating layer 15 may be a dioxide dioxide (
Si〇2)、氮化碎（Si3N4)或者是金剛石狀絕緣塗料（ DLC)。這樣，在製作電連接層14時，該電連接層14除了 與P型接觸電極125與N型接觸電極126相接觸的部分外， 099109645 表單編號A0101 第6頁/共19頁 0992017089-0 201133934 其餘部分將*能與發光結構單元12直接接觸，而是被第 一絕緣層15所間隔開，從而避免發生短路現象。 [0018] Ο ❹ [0019] 在電連接層14製作完成之後，在凹陷部13内部填充金屬 材料16。該金屬材料為銅（Cu)、金（Au)、錄⑻） 、銀（Ag)、鋁（A1)其中之一或者前述金屬材料之合 金。該金屬材料16採用電鍍的方式製作在發光結構單元 12的表面《為避免產生不必要的電學接觸，可以在相對 應的地方沈積一層第二絕緣層17。在本實施例中，該第 二絕緣層17覆蓋在電連接層14的表面，用於隔離金屬材 料16與電連接層14矣間的電性連接。在電鍍開始之前， 可以先用真空蒸發的方法蒸緣—層起錄層18，該起鑛層 18的材料為錄（Ni)、紹（A1)、銀（Ag)、翻（Pt) 、把（Pd)、敛（Τι)、金（Au)其中之一或前述材料 之合金。在本實施例中，該金屬材料16除了填充在凹陷 部13内部以外，其還可以覆蓋在該多個發光結構單元12 的表面，從而形成連續性的結構。所述填充在凹陷部13 内《卩及覆蓋在發光結構單元12表面的金屬材料1 6可增大 發光二極體100的散熱面積，從而進一步增強該發光二極 體1 0 0的散熱性能。該金屬材料丨6分為相互絕緣的兩部分 ，形成多個發光結構單元丨2共同進行對外連接的兩個電 極0 在本實施例中，該發光二極體1〇〇在工作時，所述第一多 量子井活性層122與第二多量子井活性層123所發出的光 線將從透明基板11的方向上出射到外界。由於金屬材料 16填充在凹陷部13的内部，且凹陷部13深入至第一多量 099109645 表單編號A0101 第7頁/共19頁 0992017089-0 201133934 子井活性層122與第二多量子井活性層123t，因此第一 多量子井活性層122與第二多量子井活性層123所發出的 熱量可以迅速傳遞到金屬材料16中。並且，由於金屬材 料16具有較好的散熱性能，其可以將熱量迅速散發到外 界，從而改善了該發光二極體100的散熱性能。 [0020] 請參見圖2，上述的發光二極體100的採用以下步驟製作 [0021] 步驟一：提供一個透明基板11。然後採用金屬有機氣相 沈積法(MOCVD, metal organic chemical vapor deposition)在透明基板11上依次沈積N型GaN層121、 第一多量子井活性層122、第二多量子井活性層123及P型 GaN層124以形成一發光結構。 [0022] 步驟二：採用蝕刻的方法在發光結構上製作隔離槽以形 成多個發光結構單元12，且使發光結構單元12之間電性 隔離。然後，在發光結構單元的表面製作凹陷部13，該 凹陷部13從P型GaN層124延伸到N型GaN層121，顯露出N 型GaN層121的表面。所述蝕刻的方法可以是電感耦合等 離子體蝕刻（ICP)或者是反應離子蝕刻（RIE)方法。 [0023] 步驟三：採用真空蒸鍍的方法每個發光結構單元12的P型 GaN層124表面與N型GaN層121表面分別製作P型接觸電極 125與N型接觸電極126。然後採用真空蒸發或者塗覆的方 法製作第一絕緣層15。該第一絕緣層15完全覆蓋除P型接 觸電極125與N型接觸電極126以外的區域，然後製作金屬 電連接層14將兩個發光結構單元12之間電性連接； 099109645 表單編號A0101 第8頁/共19頁 0992017089-0 201133934 [0024] [0025] Ο [0026] ❹ 步驟四：在金屬電連接層14表面製作第二絕緣層17。同 樣，該第二絕緣層17可以由真空蒸發或者塗覆的方法形 成。然後採用電鍍的方法在凹陷部13内形成金屬材料16 。在電鍍開始之前，先用真空蒸發的方法在第二絕緣層 17的表面首先形成一層起鍵層18。 在本實施例中，兩個發光結構單元12之間為串聯連接關 係。根據需要，發光結構單元12可以是複數個。該複數 個發光結構單元12可以是串聯連接關係，亦可以是並聯 連接關係，或者是串聯與並聯相結合，又或者是發光結 構單元12之間的反向並聯連接，形成交流供電的發光結 構。 圖3為本發明第二實施例的發光二極體200的結構示意圖 。該發光二極體200包括透明基板21及兩個發光結構單元 22。每個發光結構單元22包括在透明基板21上依次層疊 的Ν型GaN層221，第一多量子井活性層222,第二多量子 井活性層223，P型GaN層224以及分別與P型GaN層224與 N型GaN層221分別接觸的P型接觸電極225與N型接觸電極 226。 [0027] 發光結構單元22具有一凹陷部23。該凹陷部23從P型GaN 層224延伸到N型GaN層221，顯露出N型GaN層221的表面 ，用於製作N型接觸電極226。 該發光結構單元22還包括一第一絕緣層25，該第一絕緣 層25覆蓋除接觸電極以外的區域。一電連接層24設置於 第一絕緣層25的表面，用於連接兩個發光結構單元22相 099109645 表單編號A0101 第9頁/共19頁 0992017089-0 [0028] 201133934 鄰的N型接觸電極226與P型接觸電極225。多個發光結構 單元22之間進一步包括隔離槽29，避免發光二極體200在 工作時發光結構單元22之間存在電性干擾而造成發光結 構單元22之間產生短路現象。 [0029] 在電連接層24的表面設置有第二絕緣層27，然後在凹陷 部23的内部設置金屬材料26。在將金屬材料26電鍍到凹 陷部23表面之前，首先蒸鑛一層起鍵層28在第二絕緣層 2 7的表面。 [0030] 與第一實施例不同的是，本實施例的發光結構單元22還 包括一透明導電層227。該透明導電層227設置於P型GaN 層224與P型接觸電極225之間。該透明導電層227藉由真 空蒸鍍的方法設置於P型GaN層224的表面。該透明導電層 227的材料可以是氧化銦錫ITO、氧化銦鋅IZO或者是氧 化辞ZnO薄膜。該透明導電層227可以作為歐姆接觸層， 起到使電流在P型GaN層224充分擴散均勻的作用。 [0031] 根據需要，該發光二極體亦不限於兩個發光結構，其亦 可以是三個或者三個以上。發光結構之間的電連接關係 亦可以根據需要確定。請參見圖4，為本發明的第三實施 例的發光二極體300内部的電連接關係圖。該發光二極體 30 0包括透明基板31及設置於透明基板31的四個角上的四 個發光結構單元32。所述發光結構單元32之間設置有隔 離槽39。 [0032] 每個發光結構單元32都包括一P型接觸電極325及一N型接 觸電極326。發光結構單元32之間藉由電連接層34相互連 099109645 表單編號A0101 第10頁/共19頁 0992017089-0 201133934 接，形成串聯連接的結構。 [0033] Ο ❹ [0034] [0035] [0036] =述，光結構單元32設置有凹陷部（圖未示），該凹陷部 立15真充有金屬材料36，該金屬材料36除填充在凹陷 15的内邵外，其還填充在隔離槽39中且延伸至覆蓋多個 發光、、’。構單疋32的表面’形成較大面積的散熱結構。在 本實知例中’所述金屬材料36分為相互絕緣的第一電極 1與第一電極362。該第一電極361與形成串聯連接結 舞的起始處的發光結構單元32的Ρ型接觸電極32 5相連接 ，=第二電極362與形成串聯連接結構的結尾處的發光結 構早疋32ή^Ν型接觸電極_相連接。所述帛二電極⑽ *在夕個發光結構單元3 2的表面，形成連續的結構。 由於金屬材料36填充在凹陷部及隔離槽39處，所述發光 、、’=構單元32在工作時所產生的熱量可以迅速傳遞到金屬 材料36中。另外，由於金屬材料36還廷伸至覆蓋多個發 光結構單元32的表面，其峄然會增大散熱面積，從而使 發光二極體300的散熱效率進一步增加。 綜上所述，本發明確已符合發明專利之要件，遂依法提 出專利申請"惟，以上所述者僅為本發明之較佳實施方 式，自不能以此限制本案之申請專利範圍。舉凡熟悉本 案技藝之人士援依本發明之精神所作之等效修飾或變化 ，皆應涵蓋於以下申請專利範圍内。 【圖式簡單說明】 圖1是本發明第一實施例的發光二極體的結構示意圖。 圖2是圖1中的發光二極體的製作流程圖。 099109645 表單編號Α0101 第11頁/共19頁 0992017089-0 201133934 [0037] 圖3是本發明第二實施例的發光二極體的結構示意圖。 [0038] 圖4是本發明第三實施例的發光二極體的電連接關係示意 圖。 【主要元件符號說明】 099109645 表單編號 A0101 第 12 頁/共 19 頁 0992017089-0 [0039] 發光二極體：100、200、300 [0040] 透明基板：11、21、31 [0041] 發光結構單元：12、22、32 [0042] N型GaN層：121、221 [0043] 第一多量子井活性層：122 、222 [0044] 第二多量子井活性層：123 、223 [0045] P型GaN層：124、224 [0046] P型接觸電極：125、225、 325 [0047] N型接觸電極：126、226、 326 [0048] 透明導電層：227 [0049] 凹陷部：13、2 3 [0050] 電連接層：14、24、34 [0051] 第一絕緣層：15、25 [0052] 金屬材料：16、26、36 [0053] 第一電極：361 [0054] 第二電極：362 27 201133934 [0055] 第二絕緣層：17 [0056] 起鍍層：18、28 39 [0057] 隔離槽：19、29 〇 ❹ 099109645 表單編號A0101 第13頁/共19頁 0992017089-0Si〇2), nitrided (Si3N4) or diamond-like insulating coating (DLC). Thus, when the electrical connection layer 14 is formed, the electrical connection layer 14 is in addition to the portion in contact with the P-type contact electrode 125 and the N-type contact electrode 126, 099109645 Form No. A0101 Page 6 / Total 19 Page 0992017089-0 201133934 The portion can be directly in contact with the light-emitting structural unit 12, but is spaced apart by the first insulating layer 15, thereby avoiding a short circuit phenomenon. [0018] After the fabrication of the electrical connection layer 14 is completed, the inside of the recess 13 is filled with the metal material 16. The metal material is one of copper (Cu), gold (Au), recorded (8)), silver (Ag), aluminum (A1) or an alloy of the foregoing metal materials. The metal material 16 is formed on the surface of the light-emitting structural unit 12 by electroplating. To avoid unnecessary electrical contact, a second insulating layer 17 may be deposited at a corresponding place. In this embodiment, the second insulating layer 17 covers the surface of the electrical connection layer 14 for isolating the electrical connection between the metal material 16 and the electrical connection layer 14. Before the start of electroplating, the edge-layer recording layer 18 may be evaporated by vacuum evaporation. The material of the ore-bearing layer 18 is recorded (Ni), Shao (A1), silver (Ag), turned (Pt), One of (Pd), condensed (Τι), gold (Au) or an alloy of the foregoing. In the present embodiment, the metal material 16 may be covered on the surface of the plurality of light emitting structure units 12 in addition to being filled inside the recessed portion 13, thereby forming a continuous structure. The filling of the metal material 16 covering the surface of the light emitting structure unit 12 in the recess portion 13 can increase the heat dissipation area of the light emitting diode 100, thereby further enhancing the heat dissipation performance of the light emitting diode 100. The metal material 丨6 is divided into two parts which are insulated from each other, and a plurality of light-emitting structural units 丨2 are formed to be externally connected to each other. In the embodiment, the light-emitting diode 1 〇〇 is in operation, The light emitted by the first multi-quantum well active layer 122 and the second multi-quantum well active layer 123 will be emitted from the direction of the transparent substrate 11 to the outside. Since the metal material 16 is filled inside the recessed portion 13, and the depressed portion 13 penetrates to the first multi-number 099109645, the form number A0101, page 7 / total 19 pages 0992017089-0 201133934 the sub-well active layer 122 and the second multi-quantum well active layer 123t, so the heat emitted by the first multi-quantum well active layer 122 and the second multi-quantum well active layer 123 can be quickly transferred into the metal material 16. Moreover, since the metal material 16 has good heat dissipation performance, it can quickly dissipate heat to the outside, thereby improving the heat dissipation performance of the light emitting diode 100. [0020] Referring to FIG. 2, the above-mentioned LED device 100 is fabricated by the following steps. [0021] Step 1: A transparent substrate 11 is provided. Then, an N-type GaN layer 121, a first multi-quantum well active layer 122, a second multi-quantum well active layer 123, and a P-type are sequentially deposited on the transparent substrate 11 by metal organic chemical vapor deposition (MOCVD). The GaN layer 124 is formed to form a light emitting structure. [0022] Step 2: forming an isolation trench on the light emitting structure by etching to form a plurality of light emitting structure units 12, and electrically isolating the light emitting structure units 12. Then, a depressed portion 13 is formed on the surface of the light-emitting structural unit, and the depressed portion 13 extends from the P-type GaN layer 124 to the N-type GaN layer 121 to expose the surface of the N-type GaN layer 121. The etching method may be an inductively coupled plasma etching (ICP) or a reactive ion etching (RIE) method. [0023] Step 3: A P-type contact electrode 125 and an N-type contact electrode 126 are respectively formed on the surface of the P-type GaN layer 124 of each of the light-emitting structure units 12 and the surface of the N-type GaN layer 121 by vacuum evaporation. The first insulating layer 15 is then formed by vacuum evaporation or coating. The first insulating layer 15 completely covers a region other than the P-type contact electrode 125 and the N-type contact electrode 126, and then the metal electrical connection layer 14 is formed to electrically connect the two light-emitting structural units 12; 099109645 Form No. A0101 No. 8 Page / Total 19 pages 0992017089-0 201133934 [0024] [0026] ❹ Step 4: A second insulating layer 17 is formed on the surface of the metal electrical connection layer 14. Also, the second insulating layer 17 can be formed by vacuum evaporation or coating. A metal material 16 is then formed in the recess 13 by electroplating. Prior to the start of electroplating, a layer of bonding layer 18 is first formed on the surface of the second insulating layer 17 by vacuum evaporation. In this embodiment, the two light emitting structural units 12 are in series connection relationship. The light emitting structure unit 12 may be plural as needed. The plurality of light-emitting structural units 12 may be in a series connection relationship, or may be a parallel connection relationship, or a combination of series and parallel connection, or an anti-parallel connection between the light-emitting structure units 12 to form an AC-powered light-emitting structure. FIG. 3 is a schematic structural view of a light-emitting diode 200 according to a second embodiment of the present invention. The light emitting diode 200 includes a transparent substrate 21 and two light emitting structure units 22. Each of the light emitting structure units 22 includes a Ν-type GaN layer 221 sequentially stacked on the transparent substrate 21, a first multi-quantum well active layer 222, a second multi-quantum well active layer 223, a P-type GaN layer 224, and a P-type GaN, respectively. The layer 224 and the N-type GaN layer 221 are in contact with the P-type contact electrode 225 and the N-type contact electrode 226, respectively. [0027] The light emitting structure unit 22 has a recessed portion 23. The depressed portion 23 extends from the P-type GaN layer 224 to the N-type GaN layer 221 to expose the surface of the N-type GaN layer 221 for fabricating the N-type contact electrode 226. The light emitting structure unit 22 further includes a first insulating layer 25 covering a region other than the contact electrode. An electrical connection layer 24 is disposed on the surface of the first insulating layer 25 for connecting the two light emitting structure units 22 phase 099109645 Form No. A0101 Page 9 / Total 19 Page 0992017089-0 [0028] 201133934 Neighboring N-type contact electrode 226 Contact electrode 225 with P-type. The plurality of light emitting structure units 22 further include isolation trenches 29 to prevent electrical interference between the light emitting structure units 22 during operation of the light emitting diodes 200 to cause a short circuit between the light emitting structure units 22. [0029] A second insulating layer 27 is provided on the surface of the electrical connection layer 24, and then a metal material 26 is provided inside the recess portion 23. Before plating the metal material 26 onto the surface of the recess 23, a layer of the bonding layer 28 is first vaporized on the surface of the second insulating layer 27. [0030] Unlike the first embodiment, the light emitting structure unit 22 of the present embodiment further includes a transparent conductive layer 227. The transparent conductive layer 227 is disposed between the P-type GaN layer 224 and the P-type contact electrode 225. The transparent conductive layer 227 is provided on the surface of the P-type GaN layer 224 by vacuum evaporation. The material of the transparent conductive layer 227 may be indium tin oxide ITO, indium zinc oxide IZO or an oxidized ZnO thin film. The transparent conductive layer 227 can function as an ohmic contact layer to uniformly diffuse current in the P-type GaN layer 224. [0031] The light emitting diode is also not limited to two light emitting structures as needed, and may be three or more. The electrical connection between the light-emitting structures can also be determined as needed. Referring to Fig. 4, there is shown an electrical connection diagram of the inside of the light-emitting diode 300 according to the third embodiment of the present invention. The light emitting diode 30 includes a transparent substrate 31 and four light emitting structure units 32 disposed at four corners of the transparent substrate 31. An isolation groove 39 is disposed between the light emitting structure units 32. [0032] Each of the light emitting structure units 32 includes a P-type contact electrode 325 and an N-type contact electrode 326. The light-emitting structural units 32 are connected to each other by an electrical connection layer 34. 099109645 Form No. A0101 Page 10 of 19 0992017089-0 201133934 The structure is connected in series. [0036] [0036] [0036] The optical structure unit 32 is provided with a recessed portion (not shown), which is filled with a metal material 36, which is filled with Outside the inner portion of the recess 15, it is also filled in the isolation trench 39 and extends to cover a plurality of illuminations, '. The surface of the monolith 32 forms a heat dissipating structure of a large area. In the present embodiment, the metal material 36 is divided into a first electrode 1 and a first electrode 362 which are insulated from each other. The first electrode 361 is connected to the Ρ-type contact electrode 32 5 which forms the light-emitting structure unit 32 at the beginning of the series connection dance, and the second electrode 362 is earlier than the light-emitting structure at the end of the series connection structure. The Ν-type contact electrode _ is connected. The second electrode (10)* forms a continuous structure on the surface of the light-emitting structural unit 32. Since the metal material 36 is filled in the recessed portion and the isolation groove 39, the heat generated by the illuminating, constituting unit 32 can be quickly transferred to the metal material 36. In addition, since the metal material 36 is extended to cover the surface of the plurality of light-emitting structural units 32, the heat dissipation area is increased, so that the heat dissipation efficiency of the light-emitting diode 300 is further increased. In summary, the present invention has indeed met the requirements of the invention patent, and the patent application is filed according to law. However, the above description is only a preferred embodiment of the present invention, and the scope of the patent application of the present invention cannot be limited thereby. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the structure of a light-emitting diode according to a first embodiment of the present invention. 2 is a flow chart showing the fabrication of the light emitting diode of FIG. 1. 099109645 Form No. Α0101 Page 11 of 19 0992017089-0 201133934 [0037] FIG. 3 is a schematic structural view of a light-emitting diode according to a second embodiment of the present invention. 4 is a schematic view showing the electrical connection relationship of a light-emitting diode according to a third embodiment of the present invention. [Main component symbol description] 099109645 Form No. A0101 Page 12 of 19 0992017089-0 [0039] Light-emitting diode: 100, 200, 300 [0040] Transparent substrate: 11, 21, 31 [0041] Light-emitting structural unit : 12, 22, 32 [0042] N-type GaN layer: 121, 221 [0043] First multi-quantum well active layer: 122, 222 [0044] Second multi-quantum well active layer: 123, 223 [0045] P-type GaN layer: 124, 224 [0046] P-type contact electrode: 125, 225, 325 [0047] N-type contact electrode: 126, 226, 326 [0048] Transparent conductive layer: 227 [0049] depressed portion: 13, 2 3 [0050] Electrical connection layer: 14, 24, 34 [0051] First insulating layer: 15, 25 [0052] Metal material: 16, 26, 36 [0053] First electrode: 361 [0054] Second electrode: 362 27 201133934 [0055] Second insulating layer: 17 [0056] Plating: 18, 28 39 [0057] Isolation slot: 19, 29 〇❹ 099109645 Form number A0101 Page 13 / Total 19 page 0992017089-0