1279928 九、發明說明： 【發明所屬之技術領域】 本發明疋有關於一種製作發光二極體（1 ight emi tting diode ;簡稱LED)的方法，特別是指一種製作高亮度發光二極 體的方法。 【先前技術】 一般常見的發光一極體主要是由一藍寶石（sapphire)基 板、一形成於該藍寶石基板上並由一 η型半導體層、一 p型 半導體層及一夾置於該η型半導體層及該ρ型半導體層之間 的發光層（active layer)所構成的發光磊晶膜，及兩分別電 性連接該n型半導體層及P型半導體層的接觸電極（contact) 所構成。 由於藍寶石基板的熱傳導率（thermal conductivity)極 低’其對於由該發光二極體本身所累積的熱能無法輕易地被 排離至外界，因此，當提供於該發光二極體的注入電流 (injection current)值越高時，仍無法增加已達飽和狀態的 發光一極體之輸出功率（output power )值，而使得該發光二 極體長期以來寄存著發光亮度（brightness)無法提升且散熱 效率低等問題。 為了改善上述發光二極體的散熱（thermal dissipation) 問題’以使得提供於發光二極體上的電流可以有效地貢獻於 輸出功率，亦有發光二極體相關業者利用導電基板取代前述 的藍寶石基板並藉此導電基板提供給發光二極體散熱的功能 1279928 參閱圖1，一種習知發光二極體1，包含：一導電基板11 、一形成於該導電基板11上的發光磊晶（6扒1;&)^&1)膜13、 一夾置於該導電基板11及該發光磊晶膜13之間的貼合層i 2 及兩分別電性連接該發光磊晶膜13及該導電基板1丨的接觸 電極14。 首先，該發光二極體1的製作方法是在一藍寶石磊晶用 基板（圖未示）的一表面上形成有該發光磊晶膜13，此外，並 藉由該貼合層12黏合該發光磊晶膜13及該導電基板11以使 得該貼合層12夾置於該發光磊晶膜13及該導電基板n之間 〇 進一步地，將上述的磊晶用藍寶石基板、發光磊晶膜13 及貼合有該導電基板11的結構整體地顛倒反置，並將該藍寶 石磊晶用基板自該發光磊晶膜13移除，以便於後續可在該發 光麻日日膜13及该導電基板11分別地形成該等接觸電極14 0 由於前述的發光磊晶膜13是由以氮化鎵（GaN)為主的材 料所製成’光子（ph〇t〇n)經光電效應（ph〇t〇electric effect)自該發光蠢晶膜13產生後會朝四面八方輻射，然而 ，由於氮化鎵的折射率（η = 2· 6 )遠大於空氣的折射率 (n-Ι) ’因此’當光子經過氮化鎵與空氣的介面時，9〇%以上 的光子會遭遇到全反射（total reflection)，並嚴重地影響 3¾ 光一極體 1 的出光效率（light extracting efficiency) ο 雖然該發光二極體i可改善散熱問題並提升其輸出功率 以達到增加其發光亮度的特點。但，該發光二極體i卻存 1279928 在著光源全反射的問題，使得該發光二極體丨本身的外呷旦 子效率（external quantum)大幅地下降。 里 因此，如何降低由發光二極體與空氣介面間的折射率差 所構成的全反射問題以增加發光二極體的外部量子效率，曰 目前發光二極體相關領域者所需解決的重要課題之一。 【發明内容】 因此，本發明之目的，即在提供一種製作高亮度發光二 極體的方法。 於是’本發明製作高亮度發光二極體的方法，包含下列 步驟： (a) 於一磊晶基板上形成一發光磊晶膜； (b) 於該發光磊晶膜上結合一導電基板致使該發光磊晶 膜夾置於該磊晶基板與該導電基板之間； (c) 自該發光磊晶膜移除該磊晶基板； (d) 對移除該磊晶基板的發光磊晶膜施予隔離化 (isolation)； (e) 於移除该蠢晶基板的發光蠢晶膜上形成複數電極 (contact); (f) 在該導電基板處形成一電極；及 (g) 使用一化學濕式I虫刻法（chemical wet etching)以 一預定溫度對已移除該蟲晶基板的發光蠢晶膜粗化 (roughen)—預定時間，其中，該化學濕式蝕刻法是 使用一含有氫氧化鉀（K0H)的蝕刻劑。 本發明之功效在於，該發光磊晶膜所產生的光源可藉由 1279928 該粗糙表面以減少因發光磊晶膜與空氣間的折射率差所構成 的全反射問題，並增加本發明之發光二極體的外部量子效率 〇 【實施方式】 〈發明詳細說明〉 參閲圖2，本發明之製作高亮度發光二極體的方法，包含 下列步驟： (a) 於一磊晶基板上形成一發光磊晶膜； (b) 於該發光磊晶膜上結合一導電基板，致使該發光磊 晶膜夾置於該磊晶基板與該導電基板之間； (c) 自該發光磊晶膜移除該磊晶基板； (d) 對移除該磊晶基板的發光磊晶膜施予隔離化； (e) 於移除該磊晶基板的發光磊晶膜上形成複數電極； (Ο在該導電基板處形成一電極；及 一預定溫度對已移除該磊 一預定時間，其中，該化 含有氫氧化鉀的蝕刻劑。 (§)使用一化學濕式蝕刻法以一 晶基板的發光磊晶膜粗化一 學濕式I虫刻法是使用一含右j 水溶液。 適用於本發明之該含有氫氧化鉀的蝕刻 劑是一氫氧化鉀 較佳地 δ亥氫氧化鉀水溶液的濃度是介於 30 %至 55 〇/0之 更佳地 該氫氧化鉀水溶液的濃度是介於 40 〇/〇至 50 0/〇之 1279928 間。 較佳地’该預定溫度是介於4 0 °C至2 5 0 °C，該預定時間 是介於0.5分鐘至60分鐘。 更佳地，該預定溫度是介於50°C至10(TC，該預定時間 是介於0.5分鐘至10分鐘。 較佳地，該步驟（b)是使用黏著結合法（fusi〇n bonding))或共晶結合法（eutectic bonding)其中一者。 籲 值得一提的是，該步驟（c)是使用化學濕式蝕刻法或雷射 - 剝離法（Laser lift-off)其中一者自該發光磊晶膜移除該磊 晶基板。在一具體實施例中，該步驟（c)是使用化學濕式蝕刻 法自該發光磊晶膜移除該磊晶基板。 有關本發明之前述及其他技術内容、特點與功效，在以 下配合參考圖式之一個具體實施例的詳細說明中，將可清楚 的呈現。 〈具體實施例〉 • 以下配合參閱圖3，說明本發明製作高亮度發光二極體的 方法之一具體實施例。 首先，於一磊晶基板2上形成一具有一 n型GaN半導體 層、一 P型GaN半導體層及一夹置於該n型及p型GaN半導 體層之間的發光層的發光蠢晶膜3。 此外，利用共晶結合法並藉由一貼合層4於該發光遙晶 膜3上貼合一導電基板5，以使得該發光蟲晶膜3夹置於該蟲 晶基板2及該導電基板5之間。 後續地’利用化學蝕刻法自該發光磊晶膜3移除該磊晶 1279928 基板2，再使用乾式蝕刻（dry etching)機將該發光磊晶膜3 的邛为面積I虫刻至露出該貼合層4為止，藉以完成隔離化製 私並於該發光蟲晶膜3的一上表面定義出複數接觸區η。1279928 IX. Description of the Invention: [Technical Field] The present invention relates to a method for fabricating a light-emitting diode (LED), and more particularly to a method for fabricating a high-brightness light-emitting diode . [Prior Art] A common common light-emitting body is mainly composed of a sapphire substrate, a sapphire substrate formed on the sapphire substrate, and an n-type semiconductor layer, a p-type semiconductor layer, and a n-type semiconductor. A light-emitting epitaxial film formed of an active layer between the layer and the p-type semiconductor layer, and two contact electrodes electrically connected to the n-type semiconductor layer and the p-type semiconductor layer, respectively. Since the thermal conductivity of the sapphire substrate is extremely low, the thermal energy accumulated by the light-emitting diode itself cannot be easily discharged to the outside, and therefore, when the injection current is supplied to the light-emitting diode (injection) When the value of the current) is higher, the output power value of the light-emitting diode that has reached saturation state cannot be increased, so that the light-emitting diode has long been registered with the brightness that cannot be improved and the heat dissipation efficiency is low. And other issues. In order to improve the thermal dissipation problem of the above-mentioned light-emitting diodes, so that the current supplied to the light-emitting diode can effectively contribute to the output power, the related light-emitting diodes use a conductive substrate instead of the aforementioned sapphire substrate. Referring to FIG. 1 , a conventional light-emitting diode 1 includes a conductive substrate 11 and a light-emitting epitaxial layer formed on the conductive substrate 11 (6扒). a film 13 , a bonding layer i 2 sandwiched between the conductive substrate 11 and the luminescent epitaxial film 13 , and two electrically connected to the luminescent epitaxial film 13 and the film The contact electrode 14 of the conductive substrate 1丨. First, the light-emitting diode 1 is formed by forming the luminescent epitaxial film 13 on a surface of a sapphire epitaxial substrate (not shown), and bonding the luminescent layer by the bonding layer 12 The epitaxial film 13 and the conductive substrate 11 are disposed such that the bonding layer 12 is interposed between the luminescent epitaxial film 13 and the conductive substrate n. Further, the epitaxial sapphire substrate and the luminescent epitaxial film 13 are further formed. And the structure in which the conductive substrate 11 is bonded is integrally reversed, and the sapphire epitaxial substrate is removed from the luminescent epitaxial film 13 so as to be subsequently etched on the luminescent film 13 and the conductive substrate. 11 forming the contact electrodes 14 0 separately. Since the foregoing luminescent epitaxial film 13 is made of a material mainly composed of gallium nitride (GaN), the photon effect (ph〇t〇n) is photoelectric effect (ph〇t 〇electric effect) will be radiated in all directions from the luminescent film 13, however, since the refractive index of GaN (η = 2·6) is much larger than the refractive index of air (n-Ι) 'so' when photons When passing through the interface between GaN and air, more than 9% of photons will experience total reflection. (total reflection), and seriously affects the light extracting efficiency of the light-emitting body 1 ο Although the light-emitting diode i can improve the heat dissipation problem and increase its output power to increase its luminous brightness. However, the light-emitting diode i has a problem of total reflection of the light source 1279928, so that the external quantum efficiency of the light-emitting diode itself is greatly reduced. Therefore, how to reduce the total reflection problem caused by the difference in refractive index between the light-emitting diode and the air interface to increase the external quantum efficiency of the light-emitting diode is an important problem to be solved by the current field of light-emitting diodes. one. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method of fabricating a high brightness light emitting diode. Thus, the method of the present invention for producing a high-brightness light-emitting diode comprises the steps of: (a) forming a light-emitting epitaxial film on an epitaxial substrate; (b) bonding a conductive substrate to the light-emitting epitaxial film to cause the conductive substrate; a luminescent epitaxial film is interposed between the epitaxial substrate and the conductive substrate; (c) removing the epitaxial substrate from the luminescent epitaxial film; (d) applying a luminescent epitaxial film to remove the epitaxial substrate (iso) forming a plurality of contacts on the luminescent film that removes the stray substrate; (f) forming an electrode at the conductive substrate; and (g) using a chemical wet The chemical wet etching method roughens the luminescent film that has been removed from the insect crystal substrate at a predetermined temperature for a predetermined time, wherein the chemical wet etching method uses a hydrating hydroxide Potassium (K0H) etchant. The effect of the invention is that the light source produced by the luminescent epitaxial film can reduce the total reflection caused by the difference in refractive index between the luminescent epitaxial film and the air by using the rough surface of 1279928, and increase the illuminating light of the invention. External quantum efficiency of the polar body 实施 [Embodiment] Detailed Description of the Invention Referring to Figure 2, a method of fabricating a high-brightness light-emitting diode of the present invention comprises the following steps: (a) forming a luminescence on an epitaxial substrate (b) bonding a conductive substrate to the luminescent epitaxial film such that the luminescent epitaxial film is interposed between the epitaxial substrate and the conductive substrate; (c) removing the luminescent epitaxial film The epitaxial substrate; (d) isolating the luminescent epitaxial film from which the epitaxial substrate is removed; (e) forming a plurality of electrodes on the luminescent epitaxial film from which the epitaxial substrate is removed; Forming an electrode at the substrate; and removing the protrusion for a predetermined time from a predetermined temperature, wherein the etchant containing potassium hydroxide (§) using a chemical wet etching method to fluoresce epitaxially on a crystal substrate Membrane coarsening The aqueous solution containing potassium hydroxide is suitable for the present invention. The potassium hydroxide-containing etchant is potassium hydroxide. Preferably, the concentration of the aqueous solution of potassium hydroxide is preferably from 30% to 55 〇/0. The concentration of the aqueous potassium oxide solution is between 12 28 〇 〇 50 12 799 799 12 12 12 12 12 。 。 。 。 。 较佳 较佳 较佳 较佳 较佳 较佳 较佳 较佳 较佳 预定 预定 预定 预定 预定 预定 预定 预定 预定 预定 预定 预定 预定 预定 预定 预定 预定 预定 预定More preferably, the predetermined temperature is between 50 ° C and 10 (TC, the predetermined time is between 0.5 minutes and 10 minutes. Preferably, the step (b) is using an adhesive bonding method (fusi 〇n bonding)) or one of eutectic bonding. It is worth mentioning that step (c) is a chemical wet etching method or a laser lift-off method. One removes the epitaxial substrate from the luminescent epitaxial film. In a specific embodiment, the step (c) is to remove the epitaxial substrate from the luminescent epitaxial film using a chemical wet etching method. The foregoing and other technical contents, features and effects are combined with the following specific implementation of the reference pattern In the detailed description, it will be clearly shown. <Specific Embodiments> A specific embodiment of the method for fabricating a high-brightness light-emitting diode of the present invention will be described below with reference to FIG. 3. First, on an epitaxial substrate 2 Forming a light-emitting amorphous film 3 having an n-type GaN semiconductor layer, a p-type GaN semiconductor layer, and a light-emitting layer sandwiched between the n-type and p-type GaN semiconductor layers. Further, by eutectic bonding A conductive substrate 5 is bonded to the luminescent crystal film 3 by a bonding layer 4 such that the luminescent crystal film 3 is interposed between the worm substrate 2 and the conductive substrate 5. Subsequently, the epitaxial 1279928 substrate 2 is removed from the luminescent epitaxial film 3 by a chemical etching method, and the enamel of the luminescent epitaxial film 3 is etched into an area by using a dry etching machine to expose the sticker. By the layer 4, the isolation and privacy are completed, and a plurality of contact regions η are defined on an upper surface of the luminescent crystal film 3.
進一步地，於該導電基板5的一下表面及該發光磊晶膜3 的每一接觸區31分別形成一電極6。最後，使用25〇ml•的飽 和（saturation)氫氧化鉀水溶液（亦即；濃度為45 %的氫氧化 鉀水溶液）於70°C的蝕刻溫度下對該發光磊晶膜3實施維持5 分鐘的粗化流程，藉以使得該發光磊晶膜3的每一接觸區Μ 構成一粗糙表面31，並製得複數高亮度發光二極體。可參見附 件，為该發光磊晶膜3於化學濕式蝕刻前與蝕刻後的掃描 式電子顯祕鏡（3(：&1111111§ electr〇n micr〇sc〇pe,•簡稱 Sem)之 表面形貌圖。 此凹凸不平的粗糙表面31，，可改變光子與空氣介面之間 的入射角度，並降低發生全反射的機率，此外，亦可增加發 光磊晶膜3的表面積，進而提升發光二極體的出光效率。 —綜上所述，由本發明的製作方法所製得的發光二極體， 可藉由該粗糙表面以減少光源的全反射，並增加發光二極體 ，整體外部量子效率，進而增加發光二極體的發光亮度，確 實達到本發明之目的。 不能 惟以上所述者，僅為本發明之較佳實施而者 以此限定本發明實施之範m凡依本發明巾請專利Further, an electrode 6 is formed on the lower surface of the conductive substrate 5 and each contact region 31 of the luminescent epitaxial film 3, respectively. Finally, the luminescent epitaxial film 3 was maintained at an etching temperature of 70 ° C for 5 minutes using a 25 〇 ml•saturated potassium hydroxide aqueous solution (that is, a 45% potassium hydroxide aqueous solution). The roughening process is such that each contact region Μ of the luminescent epitaxial film 3 constitutes a rough surface 31, and a plurality of high-brightness light-emitting diodes are produced. Referring to the annex, the surface of the luminescent epitaxial film 3 before and after the chemical wet etching (3:: & 1111111 § electr〇n micr〇sc〇pe, • Sem for short) The rough surface 31 can change the incident angle between the photon and the air interface, and reduce the probability of total reflection. In addition, the surface area of the luminescent epitaxial film 3 can be increased, thereby improving the light emission. Light-emitting efficiency of the polar body. In summary, the light-emitting diode produced by the manufacturing method of the present invention can reduce the total reflection of the light source by the rough surface, and increase the overall external quantum efficiency of the light-emitting diode. Further increasing the illuminating brightness of the illuminating diode does not achieve the object of the present invention. The above description is not limited to the preferred embodiment of the present invention, so as to limit the implementation of the present invention. patent
及發明說明内容所作之簡單的等效變化與修飾，皆 明專利涵蓋之範圍内。 X 【圖式簡單說明】 10 1279928 圖1是一正視示意圖，說明一種習知的發光二極體； 圖2是一流程方塊圖，說明本發明製作高亮度發光二極 體的方法；及 圖3是一流程示意圖，說明由本發明之製作高亮度發光 二極體的方法。 1279928 【主要元件符號說明】 2....... 3…… •…發光磊晶膜 5...........導電基板 31 "… 6.....*.....電極 31，…. —粗縫表面And the simple equivalent changes and modifications made by the description of the invention are within the scope of the patent. X [Simplified description of the drawings] 10 1279928 FIG. 1 is a front elevational view showing a conventional light-emitting diode; FIG. 2 is a flow block diagram illustrating a method for fabricating a high-brightness light-emitting diode of the present invention; and FIG. It is a schematic flow chart illustrating a method of producing a high-brightness light-emitting diode according to the present invention. 1279928 [Description of main component symbols] 2....... 3...... •...Light-emitting epitaxial film 5..............Conductive substrate 31 "... 6.....*. ....electrode 31,.... — rough surface
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