201214780 J/31Upif 六、發明說明： 【發明所屬之技術領域】 本發明的示範性實施例是有關於一種發光二極體晶 片及其製造方法，且特別是有關於一種具有分佈式布拉格 反射鏡的發光二極體晶片以及其製造方法。 【先前技術】 發出藍光或紫外光波長的光的氮化鎵類（gamum nitride-based )發光二極體晶片可用在各種不同的應用。特 別地是，在市面上已有銷售發出混合色光（mixed c〇i〇r light)(例如背絲裝置、—般㈣或其他類似照明所需 的白色光）的各種不同類型發光二極體封裝體（light emitting diode package )。 因為由發光一極體封裝體所輸出的光可依發光二極體 晶片的發光效率而決定，故用以改良發光二極體晶片的發 光效率的研究持續進行著。_地是，改良發光二極體晶 片的發光效率的嘗試已在進行中。糊而言，已研究在透 明基底（例如藍寶石基底（sapphiresubstrate))的底部表 面上形成金屬反射鏡或分佈式布拉格反射鏡（⑴咖如㈣ Braggreflector’DBR)的技術。 ，1所示為根據侧技賴著在㈣^基底底部表面 上形成銘層而測得的反射率（reflectivity)。 ，圖1可知’在藍寶石基底上未形雜層時，顯示的 約為20/。，但當在藍寶石基底上形成鋁層時，在可 見波長範__的反射率約為。 201214780 37510pif 圖2所示為根據相關技術藉定期施加Ti02/Si02至藍 寶石基底的底部表面以形成DBR而測得的反射率。 如圖2所示，當形成DBR以反射從發光二極體晶片 所發出的光時’例如發出具有峰值波長（peak wavelength) 為460 nm的光。圖2顯示使用DBR的發光二極體中的反 射率在藍光波長範圍中（例如4〇〇 nm至5〇〇 nm的波長範 圍）可達到大約100%。 然而，DBR僅能增加可見光範圍中一部分的反射率。 因此，對其他範圍的反射率比圖2所示的對波長範圍4〇〇 nm至500 nm的反射率低非常多。即，如圖2所示，在大 部份反射率在波長550 nm或更大的波長下小於5〇%時， 在約520 urn或更大波長的反射率突然減小。 因此，將使用DBR的發光二極體晶片裝設在發光二 極體封裝體中以發出白光時，對於從發光二極體晶片所發 出的藍色波長顧的光’ DBR騎高反料，但對於在綠 色及/或紅色波長範圍中發出的光，DBR並未顯示有效反 射特性。因此’改良發光二極體的發纽率有其限 【發明内容】 "本發明t示範性實施例提供一種可增加提供現合色 光（例如白光）的發光二極體封裝體的發光效率的一 極體晶片及其製造方法。 一 本，明之示範性實施例亦提供一種在廣大波長範圍 内具有局反射率的DBR以及具有此DBR的發光二極體晶 片0 5 201214780 3/MUpif 本發明附加的特徵將於以下說 部分將顯而易知，或者可藉著實行本發二;㈣ 本發明之不範性實施例揭露—種發光二極體晶片，其 ^ ·具有第—表面與第二表面的基底；配置在基底的第 面上的發光結構，此發光結構包括配置在第一導電型 半導體層及第二導電型半導體層之⑽主動層；配置在基 底的第二表©上的分佈式布拉格反射鏡，此分佈式布拉格 反射鏡反射由發光結構發丨的光；以及配置在此分佈式布 拉格反,鏡上的金屬層。此分佈式布拉格反射鏡對於在藍 光波長範ϋ中的第—波長的光、在綠光波長範圍中的第二 波長的光及在紅光波長範圍中的第三波長的光具有至少 90%的反射率。 本發明之示範性實施例亦揭露一種製造發光二極體 晶片的方法，此方法包括：在基底的第一表面上形成發光 結構，藉著研磨基底的第二表面而移除一部分基底 ;在研 磨後’藉著磨光（lapping)基底而減少基底的第二表面的 表面粗縫度；以及在基底的第二表面上形成分佈式布拉格 反射鏡。此發光結構包括第一導電型半導體層、第二導電 型半導體層與配置在第一導電型半導體層及第二導電型半 導體層之間的主動層。 應理解的是’前述一般性說明及後述詳細說明均為示 範性及解釋性的，且意為提供本發明的進一步解釋，如所 主張之權利範圍。 為讓本發明之上述特徵和優點能更明顯易懂’下文特 ⑤ 201214780 37510pif 舉實施例’並配合所附圖式作詳細說明如下。 【實施方式】 以下將參照所附圖式’對本發明進行更完整的說明， 所附圖式中繪示本發明的示範性實施例。然而，本發明可 具體表現於許多不同形式中，而不應被理解為限制於此處 提出之示範性實施例中。更確切而言，提供此些實施例以 使揭露内容完整，且能完全傳達本發明的範圍予所屬技術 領域中具通常知識者。在此些圖式中，可能會誇大層及區 域的尺寸以使圖式清楚。圖式中類似的標號表示類似的元 件。 圖3為根據本發明的示範性實施例所繪示具有分佈式 布拉格反射鏡45的發光二極體2〇的剖面圖，而圖4為圖 3的分佈式布拉格反射鏡45的放大剖面圖。 參照圖3，發光二極體晶片2〇包括基底21、發光結 構30及分佈式布拉格反射鏡45❶此外，此發光二極體晶 片20可包括緩衝層23、透明電極31、p電極墊33、n電 極墊35、反射金屬層51及保護層53。 基底21為透明基底，例如為藍寶石或碳化矽（sic)， 但不特別限定於此。上部表面（即，基底21的前表面）可 具有預定的圖案，如圖案化的藍寶石基底 sapphire substrate ’ PSS)。同時’基底21的範圍決定整體 晶片區域。在本發明的示範性實施例中，#發光二極體晶 片的晶片區域相對增加時，反射效果增加。因此，基底21 的範圍可為—或者更大。在—些實施例中，其可 201214780 / ^ 1 vpx/ 為1 mm2或者更大。 在基底21上放置發光結構3(μ此發光結構3〇包括第 一導電型半導體層25、第二導電型半導體層29及配置在 第一導電型半導體層25和第二導電型半導體層29之間的 主動層27。在此配置中，第一導電型半導體層乃和第二 導電型半導體層29具有彼此相反的導電型。第一導電型可 為η型’而第二導電型可為p型’反之亦然。 第一導電型半導體層25、主動層27及第二導電型半 導體層29可由氮化鎵類化合物（即，（Α1，喊训）材料 製成。決定主動層27的構成元素和組成以發出所靈咕 光，例如紫外光或藍光。第一導電型半導體層25及/或第 一導電型半導體層29可如圖中所示以單層結構形成，或者 可以多層結構形成。此外，主動層27可形成為單一量子井 結構或多重量子井結構。另外，緩衝層23可介在基底21 和第一導電型半導體層25之間。 半導體層25、27及29可使用金屬-有機化學氣相沈積 (metal-organic chemical vapor deposition，MOCVD )技術 或分子束蟲晶（molecular beam epitaxy，MBE)技術而形 成，且可藉微影及姓刻製程圖案化第一導電型半導體層25 的區域使其部分暴露。 同時’透明電極層31可由例如氧化銦錫（indium如 oxide’ITO)或鎳/金（Ni/Au)而形成在第二導電型半導 體層29上《由於具有比第二導電型半導體層29低的比電 阻值（specificresistance)，透明電極層31用以散佈電流。 8 ⑤ 201214780 J/DlUplf 在透明電極層31上形成p電極墊33，而在第一導電型半 導體層25上形成η電極墊35 ^如圖所示，p電極墊33可 透過透明電極層31而電性連接至第二導電型半導體層29。 同時，在下部（即’基底21的背面）放置分佈式布 拉格反射鏡45。分佈式布拉格反射鏡45包括第一分佈式 布拉格反射鏡40及第二分佈式布拉格反射鏡5〇。 參照圖4,第一分佈式布拉格反射鏡4〇藉著重複多對 第一材料層40a與第二材料層4〇b而形成，而第二分佈式 布拉格反射鏡50藉著重複多對第三材料層5〇a與第四材料 層50b而形成。多對第一材料層4〇a與第二材料層4〇b對 於在紅色波長範圍的光（例如55〇11111或63〇11111)比對於 在藍光波長範圍的光具有相對較高的反射率，而第二分佈 式布拉格反射鏡50對於在藍色波長範圍的光（例如46〇nm 的光）比對於在紅色或綠色波長範圍的光具有相對較高的 反射率。在此情況下，於第一分佈式布拉格反射鏡4〇中的 材料層40a與材料層40b的光學厚度比第二分佈式布拉格 反射鏡50中的材料層50a與材料層5〇b的光學厚度厚，或 反之亦然，但不限於此。 第一材料層40a可和第三材料層5〇a為相同材料，即， 具有相同的折射係數(11)(1^6^比代化(3狀（11))，而第二材 料層40b可和第四材料層50b為相同材料，即，具有二同 的折射係數(η)。舉例而言，第一材料層4〇a和第^材料層 5〇a可由二氧化鈦（Ti〇2)製成（n約等於2 5)，而第二 材料層40b和第四材料層50b可由二氧化矽（Si〇2)製成 201214780 f ^ Λ (n約等於1.5)。 同時’第一材料層40a的光學厚度（折射率x厚度） 可實質上與第二材料層40b的光學厚度具有整數的倍數關 係’而其光學厚度可實質上彼此相同。此外，第三材料層 50a的光學厚度可實質上與第四材料層5〇b的光學厚度具 有整數的倍數關係’而其光學厚度可實質上彼此相同。 此外，第一材料層40a的光學厚度可比第三材料層5〇a 的光學厚度厚’而第二材料層40b的光學厚度可比第四材 料層50b的光學厚度厚。第一材料層4〇a、第二材料層4〇b、 第三材料層50a及第四材料層5〇b的光學厚度可藉著控制 每一個材料層的反射係數及/或厚度來控制。 參照回圖3 ’由鋁（A1)、銀（Ag)或铑（Rh)或類 似物製成的反射金屬層51可在布拉格反射鏡45的下部部 分上形成，而用以保護布拉格反射鏡45的保護層53可形 成於其上。保§蔓層53可由任何金屬層（例如鈦（丁丨）、絡 (Cr)、鎳（Ni)、鉑（Pt)、组（Ta)和金（Au)或其 合金）製成。反射金屬層51或保護層53保護布拉格反射 鏡45避免外來衝擊或污染。舉例而言，當發光二極體晶片 被裝設在發光二極體封裝中時，反射金屬層51或保護層 53防止分佈式布拉格反射鏡45自例如黏著劑的材料變 形。此外，反射金屬層51可反射透過分佈式布拉格反射鏡 45所傳遞的光。因此，分佈式布拉格反射鏡45的厚度可 相對地減少。分佈式布拉格反射鏡45顯示相對高的反射 率，但可傳遞具有大的入射角度的長波長範圍的可見光。 ⑤ 201214780 37510pif 因此反射金屬層51可配置在分佈式布拉格反射鏡45的 下部部分以反射透過分佈式布拉格反射鏡45的光，藉此增 進發光效率。 一根據本不範性實施例，提供包括對相對長波長的可見 光具有高反射率的第一分佈式布拉格反射鏡4〇及對相對 短波長的可見光具有g反射率的第二分佈式布拉格反射鏡 5〇的分佈式布拉格反射鏡45,其中第一分佈式布拉格反射 鏡40及第二分佈式布拉格反射鏡5〇堆疊而形成分佈式布 拉格反射鏡45。透過結合第一分佈式布拉格反射鏡4〇及 第二分佈式布拉格反射鏡50，分佈式布拉格反射鏡45可 增加在大部分可見光範圍内的光的反射率。 根據相關技術的分佈式布拉格反射鏡對特定波長範 圍的光具有高反射率，但對於不同波長範圍的光具有相對 低的反射率，使得改良在發白光的發光二極體封裝體中的 發光效率有其限制。然而，根據本示範性實施例，分佈式 布拉格反射鏡45對藍色波長範圍的光可具有高反射率，而 對於在綠色波長範圍的光和在紅色波長範圍的光一樣具有 尚反射率’藉此使得改善發光二極體封裝體的發光效率能 實現0 匕 此外’與第二分佈式布拉格反射鏡50的配置比第一 分佈式布拉格反射鏡40更靠近基底21的情況相較，在第 一分佈式布拉格反射鏡40的配置比第二分佈式布拉格反 射鏡50更靠近基底的情況下，分佈式布拉格反射鏡衫中 光的散失可進一步減低。 11 201214780 •J t λ. 雖然本示範性實施例說明兩種反射鏡，即，第一分佈 式布拉格反射鏡40與第二分佈式布拉格反射鏡5〇，但可 使用更多種反射鏡。此情況下，對於長波長具有相對高反 射率的反射鏡可相對較靠近發光結構30而置放。 此外，在本示範性實施例中，於第一分佈式布拉格反 射鏡40中的第一材料層40a的厚度彼此可不相同。再者， 第二材料層40b的厚度彼此可不相同。另外，於第二分佈 式布拉格反射鏡50中的第三材料層5〇a的厚度彼此可不相 同。此外，第四材料層40b的厚度彼此可不相同。 本示範性實施例說明材料層40a、材料層40b、材料 層50a與材料層50b為由二氧化矽（si〇2)或二氧化鈦 (Τι〇2)製成，但不限於此。因此，它們可由其他材料（例 如氮化矽（SisN4)、化合物半導體或其類似物）製成。然 而，在第一材料層40a與第二材料層40b之間的折射率差 異以及在第三材料層50a與第四材料層50b之間的折射率 差異可至少為0.5。 此外，在第一分佈式布拉格反射鏡4〇中的第一材料 層40a和第二材料層4〇b的對數愈多且在第二分佈式布拉 格反射鏡50中的第三材料層50a和第四材料層50b的對數 愈多，反射率會變得愈高。全部的對數共可為20或者更多。 可在形成分佈式布拉格反射鏡45之前控制基底21的 彦面之表面粗糙度。當基底21的背面之表面粗糙度相對大 時’其可能難以在廣大波長範圍中藉分佈式布拉格反射鏡 45而獲得高反射率。當分佈式布拉格反射鏡45和基底21 201214780 37510pif 間的界面有缺陷’分佈式布拉格反射鏡45會易於變形。即 使在將發光二極體晶片裝設至例如發光二極體封裝體中時 施加輕微的熱處理（thermal process)，此變形仍可能造成 分佈式布拉格反射鏡45折射率減小的問題。可控制基底 21的背面的表面粗糙度使其具有3 nm或更小的均方根 (root-mean-square，RMS)值。或者，基底21的背面的 表面粗糙度可具有2 nm或更小的RMS值。在一些實施例 中’其可具有1 nm或更小的RMS值。 現在將說明製造分佈式布拉格反射鏡45及發光二極 體晶片的方法。 首先’在形成分佈式布拉格反射鏡45前控制基底21 的表面粗縫度。舉例而言’其上形成有發光結構的基底21 的背面最先被研磨，以移除一部分基底21。在此情況下， 基底21的背面藉著研磨（grinding)而被刮劃丨沉如也）， 使其相對地非常粗糙。其後’以具有小顆粒的研磨漿對基 底21的表面進行磨光（iapping)。在磨光製程中，溝槽 (groove)(如基底21的表面中的刮痕等）的深度被減少， 藉此減少了表面粗糙度❶在此情況下，基底21的背面的表 面粗糙度可藉著控制磨光製程中使用的鑽石研磨漿的顆粒 尺寸以及表面平板（surface plate)而控制在3 μιη者更小。 然而，一般而言，難以僅使用利用表面平板和研磨漿顆粒 的磨光製程來控制表面粗縫度。因此，在藉著磨光製程來 減少表面粗糙度之後’基底21的背面可藉著化學機械研磨 (chemical mechanical polishing，CMP)製程進行拋光。 13 201214780， 基底21的背面的表面粗糙度可藉著CMP製程控制而達到 1 nm或者更小。 然後，具有不同折射率的材料層（如Ti〇2、Si〇2與 SisN4或其類似物）交替地沈積在基底21的表面上。這些 材料層的沈積可藉不同的方法進行，如濺鍍（sputtering 電子束沈積（electron beam deposition )、電漿輔助化學氣 相沈積（plasma enhanced chemical vapor deposition， PECVD )法等。特別的是，可使用離子輔助沈積（i〇n沾以对以 deposition)。離子辅助沈積藉著測量沈積在基底21上的 材料層的反射率而形成具有適當厚度的材料層，使其適於 形成分佈式布拉格反射鏡的材料層。 在形成分佈式布拉格反射鏡之後，金屬層可在分佈式 布拉格反射鏡上形成。其後，基底被切塊，從而完成個別 的發光二極體晶片。 圖5所示為根據本發明的另一示範性實施例的分佈式 布拉格反射鏡55的剖面圖。根據本示範性實施例的發光二 極體晶片實質上與參照圖3及圖4說明的發光二極體晶片 類似。圖3及圖4顯示並說明分佈式布拉格反射鏡45具有 第一分佈式布拉格反射鏡40與第二分佈式布拉格反射鏡 50的堆疊結構。另一方面，在根據本示範性實施例的分佈 式布拉格反射鏡55中，混合多對第一材料層40a和第二材 料層40b與多對第三材料層50a和第四材料層5〇b。換句 話說’至少一對第三材料層50a和第四材料層50b置放在 多對第一材料層40a和第二材料層40b之間。此外，至少 201214780 3751〇pif 一對第一材料層40a和第一材料層40b置放在多對第三材 料層50a和第四材料層50b之間。在此種配置中，第一材 料層4〇a、第二材料層4〇b、第三材料層5〇a和第四材料層 5〇b的光學厚度被控制，以對於在廣大可見光範圍内的光 具有向反射率。因此，每個構成分佈式布拉格反射鏡的材 料層的光學厚度彼此可不相同。 圖6為根據本發明的另一示範性實施例所示的具有多 個發光單元的發光二極體晶片20a的剖面圖。 參照圖6 ’發光二極體晶片20a包括在基底21上的多 個發光單元。此外，發光二極體晶片2〇a可包括分佈式布 拉格反射鏡45和金屬層51及/或保護層53。 基底21和分佈式布拉格反射鏡45類似於參照圖3、 圖4及圖5而說明的分佈式布拉格反射鏡，因此將省略其 詳細說明。然而，基底21可為與多個發光單元電絕緣的絕 緣體。舉例而言，基底21可為圖案化的藍寶石基底。 同時，置放多個相互隔離的發光單元30。多個發光單 元30的每一個與參照圖3的發光結構3〇相同，因此將省 略其中的詳細說明。此外，緩衝層23可介在發光單元30 與基底21間，且缓衝層23亦可彼此相互隔離。 第一絕緣層37覆蓋發光單元3〇的前表面。第一絕緣 層37具有在第一導電型半導體層25上的開口及在第二導 電型半導體層29上的開口。發光單元3〇的側壁被第一絕 緣層37所覆蓋。第一絕緣層37亦覆蓋在發光單元3〇之間 區域的基底21。第一絕緣層37可由二氧化矽（Si〇2)層 15 201214780 或氮化碎（silicon nitride)層形成，且可為在2〇〇°c至300 °C的溫度範圍中使用電漿化學氣相沈積法所形成的詹。在 此情況中，可形成第一絕緣層37而具有4500 A至1 μιη 的厚度。當形成第一絕緣層而具有小於4500人的厚度時， 由於在發光單元底部侧的階梯覆蓋特性（step c〇verage characteristic)而會形成具有相對小的厚度的第一絕緣層， 且可能在接線（wiring)與形成在第一絕緣層上的發光單 元之間發生電性短路（electrical short circuit)。同時，當 第一絕緣層的厚度變得較大時，可預防電性短路，但光的 透射率（transmittance)可能劣化而減少了發光效率。因此， 較佳為形成厚度不超過1 μιη的第一絕緣層。 同時，在第一絕緣層37上形成接線39 »接線39透過 開口而電性連接至第一導電型半導體層25和第二導電型 半導體層29。透明電極層31可配置於第二導電型半導體 層29上’且接線可連接至透明電極層31。此外，接線39 分別電性連接相鄰的發光單元30的第一導電型半導體層 25至第二導電型半導體層29，使得發光單元3〇的串聯陣 列可形成。可形成多個串聯陣列，並各自反向並聯，使得 匕們可連接至交流電（alternating current，AC )電源。此 外，連接至發光單元的串聯陣列的橋接整流器（未繪示） 可被連接，且發光單元可在交流電電源下以此橋接整流器 而驅動。此橋接整流器可藉連接具有相同結構的發光單元 (如使用接線29的發光單元3〇)。 另一方面，接線可將相鄰發光單元的第一導電型半導 201214780 37510pif 個發光單心接。因此，可提供以_及並聯方式連接的多 曰石可由導體材料（例如摻雜的半導體材料(如多 ί 39所製成。特別地是’可以多層結構形成接 ;缠4顧或欽的下層及鉻或銳的上層。此外，金、金 錄或金/链的金屬層可介在下層與上層之間。 ㈣f ^絕緣層41可覆蓋接線39與第一絕緣層37。第二 了接心Q ^止接魏氣或其他類似物污染，並防止 、、’ 一發光單元30因外部衝擊而被損壞。 隱! 層41可以與第一絕緣層37及氧切層相同 的材枓或氮切層形成。第二絕緣層41可為在獅ec至 3〇〇 C的溫度範财使用f漿化學氣相沈積法⑽c则 =形成的層，與第—絕緣層類似。此外，當第—絕緣層藉 者使用PECVD法形成時，第二絕緣層可在第一絕緣層的 沈積溫度（deP〇sltion temperature)的·2〇%至+2〇%之溫度 範圍中/尤積，或者可在相同沈積溫度下沈積。 同時，當與第一絕緣層37相比，第二絕緣層Μ可相 對地薄’並可具有500 A或更大的厚度。第二絕緣層41 相對比第-絕緣層37薄’可防止第二絕緣層自第一絕 剝落。此外，當第二絕緣層較2500人薄時，其可能難以保 護接線與發光單元免受外界衝擊或濕氣的滲透。 〃 同時，構光體層43可置放在發光二極體晶片施上。 磷光體層43可為樹脂分散在磷光體中的層或藉著電泳方 17201214780 J/31Upif VI. Description of the Invention: [Technical Field] The present invention relates to a light-emitting diode wafer and a method of fabricating the same, and more particularly to a distributed Bragg mirror A light-emitting diode wafer and a method of manufacturing the same. [Prior Art] A gamum nitride-based luminescent diode chip that emits light of a blue or ultraviolet wavelength can be used in a variety of different applications. In particular, a variety of different types of light-emitting diode packages have been commercially available for the sale of mixed c〇i〇r light (eg, back-wire devices, general (four) or other similar lighting required white light). Light emitting diode package. Since the light output from the light-emitting diode package can be determined by the light-emitting efficiency of the light-emitting diode wafer, research for improving the light-emitting efficiency of the light-emitting diode wafer has continued. At the same time, attempts to improve the luminous efficiency of the light-emitting diode wafer are already underway. For the paste, a technique of forming a metal mirror or a distributed Bragg mirror ((1) Coffee (4) Braggreflector' DBR) on the bottom surface of a transparent substrate such as a sapphire substrate has been studied. , 1 shows the reflectivity measured according to the side technique by forming a layer on the bottom surface of the substrate. Fig. 1 shows that when the layer is not formed on the sapphire substrate, it is about 20/. However, when an aluminum layer is formed on a sapphire substrate, the reflectance at a visible wavelength range is about. 201214780 37510pif Figure 2 shows the reflectance measured by periodically applying Ti02/SiO2 to the bottom surface of the sapphire substrate to form a DBR according to the related art. As shown in Fig. 2, when a DBR is formed to reflect light emitted from a light-emitting diode wafer, for example, light having a peak wavelength of 460 nm is emitted. Figure 2 shows that the reflectance in a light-emitting diode using DBR can reach about 100% in the blue wavelength range (e.g., a wavelength range of 4 〇〇 nm to 5 〇〇 nm). However, DBR can only increase the reflectivity of a portion of the visible range. Therefore, the reflectance for other ranges is much lower than the reflectance for the wavelength range of 4 〇〇 nm to 500 nm as shown in FIG. 2 . That is, as shown in Fig. 2, when most of the reflectance is less than 5 % at a wavelength of 550 nm or more, the reflectance at a wavelength of about 520 urn or more suddenly decreases. Therefore, when a light-emitting diode chip using DBR is mounted in a light-emitting diode package to emit white light, the light of the blue wavelength emitted from the light-emitting diode wafer is highly reflective, but For light emitted in the green and/or red wavelength range, DBR does not exhibit effective reflection characteristics. Therefore, the 'improvement of the light-emitting diode has a limited rate of development. [Invention] The exemplary embodiment of the present invention provides an increase in luminous efficiency of a light-emitting diode package that provides ready-to-color light (for example, white light). A monolithic wafer and a method of manufacturing the same. An exemplary embodiment of the present invention also provides a DBR having a local reflectance over a wide wavelength range and a light emitting diode wafer having the DBR. 0 5 201214780 3/MUpif Additional features of the present invention will be apparent in the following sections. However, it is also known that the present invention can be implemented by the present invention; (iv) an exemplary embodiment of the present invention discloses a light-emitting diode wafer having a substrate having a first surface and a second surface; a light-emitting structure on the surface, the light-emitting structure comprising (10) active layers disposed on the first conductive type semiconductor layer and the second conductive type semiconductor layer; a distributed Bragg mirror disposed on the second surface of the substrate, the distributed Prague The mirror reflects the light that is emitted by the light-emitting structure; and the metal layer disposed on the distributed Bragg reflector. The distributed Bragg mirror has at least 90% of the first wavelength in the blue wavelength range, the second wavelength in the green wavelength range, and the third wavelength in the red wavelength range. Reflectivity. An exemplary embodiment of the present invention also discloses a method of fabricating a light emitting diode wafer, the method comprising: forming a light emitting structure on a first surface of the substrate, removing a portion of the substrate by grinding the second surface of the substrate; Thereafter, the surface roughness of the second surface of the substrate is reduced by lapping the substrate; and a distributed Bragg mirror is formed on the second surface of the substrate. The light emitting structure includes a first conductive type semiconductor layer, a second conductive type semiconductor layer, and an active layer disposed between the first conductive type semiconductor layer and the second conductive type semiconductor layer. It is to be understood that the foregoing general description and the appended claims The above features and advantages of the present invention will be more apparent and understood. The following is a detailed description of the embodiments of the present invention. The present invention will now be described more fully hereinafter with reference to the appended claims However, the invention may be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough, and the scope of the invention will be fully disclosed. In these figures, the dimensions of layers and regions may be exaggerated to make the drawings clear. Like numbers in the drawings indicate like elements. 3 is a cross-sectional view of a light emitting diode 2A having a distributed Bragg mirror 45, and FIG. 4 is an enlarged cross-sectional view of the distributed Bragg mirror 45 of FIG. 3, in accordance with an exemplary embodiment of the present invention. Referring to FIG. 3, the LED substrate 2 includes a substrate 21, a light emitting structure 30, and a distributed Bragg mirror 45. Further, the LED wafer 20 may include a buffer layer 23, a transparent electrode 31, and a p-electrode pad 33, n. The electrode pad 35, the reflective metal layer 51, and the protective layer 53. The substrate 21 is a transparent substrate such as sapphire or sic, but is not particularly limited thereto. The upper surface (i.e., the front surface of the substrate 21) may have a predetermined pattern such as a patterned sapphire substrate sapphire substrate 'PSS). At the same time, the extent of the substrate 21 determines the overall wafer area. In an exemplary embodiment of the present invention, when the wafer area of the #LED chip is relatively increased, the reflection effect is increased. Therefore, the extent of the substrate 21 can be - or greater. In some embodiments, it may be 201214780 / ^ 1 vpx / 1 mm 2 or greater. The light emitting structure 3 is placed on the substrate 21 (the light emitting structure 3 includes the first conductive type semiconductor layer 25, the second conductive type semiconductor layer 29, and the first conductive type semiconductor layer 25 and the second conductive type semiconductor layer 29). The active layer 27. In this configuration, the first conductive type semiconductor layer and the second conductive type semiconductor layer 29 have opposite conductivity types. The first conductive type may be an n type ' and the second conductive type may be a p The first conductive semiconductor layer 25, the active layer 27, and the second conductive semiconductor layer 29 may be made of a gallium nitride-based compound (i.e., (喊1, shouting) material. The composition of the active layer 27 is determined. The element and composition are emitted to emit a glare, such as ultraviolet light or blue light. The first conductive type semiconductor layer 25 and/or the first conductive type semiconductor layer 29 may be formed in a single layer structure as shown in the drawing, or may be formed in a multilayer structure. Further, the active layer 27 may be formed as a single quantum well structure or a multiple quantum well structure. Further, the buffer layer 23 may be interposed between the substrate 21 and the first conductive type semiconductor layer 25. The semiconductor layers 25, 27, and 29 may use a metal - organic Formed by a metal-organic chemical vapor deposition (MOCVD) technique or a molecular beam epitaxy (MBE) technique, and the first conductive semiconductor layer 25 can be patterned by a lithography and a surname process. The region is partially exposed. Meanwhile, the transparent electrode layer 31 may be formed on the second conductive type semiconductor layer 29 by, for example, indium tin oxide (indium such as oxide'ITO) or nickel/gold (Ni/Au). The conductive semiconductor layer 29 has a low specific resistance, and the transparent electrode layer 31 is used to spread the current. 8 5 201214780 J/DlUplf The p-electrode pad 33 is formed on the transparent electrode layer 31, and the first conductive type semiconductor layer 25 is formed. The n-electrode pad 35 is formed thereon. As shown, the p-electrode pad 33 is electrically connected to the second conductive semiconductor layer 29 through the transparent electrode layer 31. Meanwhile, the lower portion (i.e., the back of the substrate 21) is distributed. Bragg mirror 45. The distributed Bragg mirror 45 comprises a first distributed Bragg mirror 40 and a second distributed Bragg mirror 5A. Referring to Figure 4, the first distributed Bragg mirror 4 The plurality of pairs of the first material layer 40a and the second material layer 4b are formed by repeating, and the second distributed Bragg mirror 50 is formed by repeating a plurality of pairs of the third material layer 5a and the fourth material layer 50b. The plurality of pairs of the first material layer 4a and the second material layer 4b have a relatively higher reflectance for light in the red wavelength range (for example, 55〇11111 or 63〇11111) than for light in the blue wavelength range. The second distributed Bragg mirror 50 has a relatively high reflectivity for light in the blue wavelength range (eg, 46 〇 nm light) than for the red or green wavelength range. In this case, the optical thickness of the material layer 40a and the material layer 40b in the first distributed Bragg mirror 4〇 is greater than the optical thickness of the material layer 50a and the material layer 5〇b in the second distributed Bragg mirror 50. Thick, or vice versa, but not limited to this. The first material layer 40a may be the same material as the third material layer 5〇a, that is, have the same refractive index (11) (1^6^ ratio (3 shape (11)), and the second material layer 40b It may be the same material as the fourth material layer 50b, that is, having the same refractive index (η). For example, the first material layer 4〇a and the second material layer 5〇a may be made of titanium dioxide (Ti〇2). (n is approximately equal to 2 5), and the second material layer 40b and the fourth material layer 50b may be made of cerium oxide (Si〇2) 201214780 f ^ Λ (n is approximately equal to 1.5). Meanwhile, the first material layer 40a The optical thickness (refractive index x thickness) may substantially have an integer multiple relationship with the optical thickness of the second material layer 40b' and its optical thickness may be substantially identical to each other. Further, the optical thickness of the third material layer 50a may be substantially The optical thickness of the fourth material layer 5〇b has an integer multiple relationship' and the optical thicknesses thereof may be substantially identical to each other. Further, the optical thickness of the first material layer 40a may be thicker than the optical thickness of the third material layer 5〇a' The optical thickness of the second material layer 40b may be thicker than the optical thickness of the fourth material layer 50b. The optical thickness of the layer 4A, the second material layer 4b, the third material layer 50a, and the fourth material layer 5b can be controlled by controlling the reflection coefficient and/or thickness of each material layer. 3' A reflective metal layer 51 made of aluminum (A1), silver (Ag) or rhodium (Rh) or the like may be formed on the lower portion of the Bragg mirror 45 to protect the protective layer of the Bragg mirror 45. 53 may be formed thereon. The protective layer 53 may be any metal layer (for example, titanium (butadiene), complex (Cr), nickel (Ni), platinum (Pt), group (Ta) and gold (Au) or The alloy metal layer 51 or the protective layer 53 protects the Bragg mirror 45 from external impact or contamination. For example, when the light emitting diode wafer is mounted in the light emitting diode package, the reflective metal layer 51 Or the protective layer 53 prevents the distributed Bragg mirror 45 from being deformed from a material such as an adhesive. Further, the reflective metal layer 51 can reflect the light transmitted through the distributed Bragg mirror 45. Therefore, the thickness of the distributed Bragg mirror 45 can be Relatively reduced. Distributed Bragg mirror 45 shows relative High reflectivity, but can transmit visible light in a long wavelength range with a large angle of incidence. 5 201214780 37510pif Thus the reflective metal layer 51 can be disposed in the lower portion of the distributed Bragg mirror 45 to reflect through the distributed Bragg mirror 45 Light, thereby enhancing luminous efficiency. According to an exemplary embodiment, a first distributed Bragg mirror 4 having high reflectivity for relatively long wavelength visible light and a g reflectance for relatively short wavelength visible light are provided. A distributed Bragg mirror 45 of the second distributed Bragg mirror 5〇, wherein the first distributed Bragg mirror 40 and the second distributed Bragg mirror 5〇 are stacked to form a distributed Bragg mirror 45. By combining the first distributed Bragg mirror 4 and the second distributed Bragg mirror 50, the distributed Bragg mirror 45 can increase the reflectivity of light over most of the visible range. A distributed Bragg mirror according to the related art has high reflectance for light of a specific wavelength range, but has relatively low reflectance for light of different wavelength ranges, so that luminous efficiency in a white-emitting light-emitting diode package is improved There are restrictions. However, according to the present exemplary embodiment, the distributed Bragg mirror 45 may have high reflectance for light of a blue wavelength range, and have a good reflectance for light of a green wavelength range and light of a red wavelength range. This makes it possible to improve the luminous efficiency of the light-emitting diode package by 0 匕 in addition to the case where the configuration of the second distributed Bragg mirror 50 is closer to the substrate 21 than the first distributed Bragg mirror 40, in the first In the case where the configuration of the distributed Bragg mirror 40 is closer to the substrate than the second distributed Bragg mirror 50, the loss of light in the distributed Bragg mirror shirt can be further reduced. 11 201214780 • J t λ. Although the present exemplary embodiment illustrates two types of mirrors, namely, the first distributed Bragg mirror 40 and the second distributed Bragg mirror 5〇, more types of mirrors can be used. In this case, a mirror having a relatively high reflectance for a long wavelength can be placed relatively close to the light emitting structure 30. Further, in the present exemplary embodiment, the thicknesses of the first material layers 40a in the first distributed Bragg mirror 40 may be different from each other. Furthermore, the thicknesses of the second material layers 40b may be different from each other. Further, the thicknesses of the third material layers 5a in the second distributed Bragg mirror 50 may be different from each other. Further, the thicknesses of the fourth material layers 40b may be different from each other. The present exemplary embodiment illustrates that the material layer 40a, the material layer 40b, the material layer 50a, and the material layer 50b are made of cerium oxide (si〇2) or titanium dioxide (Τι〇2), but are not limited thereto. Therefore, they can be made of other materials such as tantalum nitride (SisN4), compound semiconductors or the like. However, the difference in refractive index between the first material layer 40a and the second material layer 40b and the difference in refractive index between the third material layer 50a and the fourth material layer 50b may be at least 0.5. Furthermore, the more the number of pairs of the first material layer 40a and the second material layer 4〇b in the first distributed Bragg mirror 4〇 and the third material layer 50a and the first in the second distributed Bragg mirror 50 The more the number of pairs of the four material layers 50b, the higher the reflectance becomes. The total number of logs can be 20 or more. The surface roughness of the face of the substrate 21 can be controlled before the distributed Bragg mirror 45 is formed. When the surface roughness of the back surface of the substrate 21 is relatively large, it may be difficult to obtain a high reflectance by the distributed Bragg mirror 45 in a wide wavelength range. When the interface between the distributed Bragg mirror 45 and the substrate 21 201214780 37510pif is defective, the distributed Bragg mirror 45 is easily deformed. Even if a slight thermal process is applied when mounting the light-emitting diode wafer into, for example, a light-emitting diode package, this deformation may still cause a problem of a decrease in the refractive index of the distributed Bragg mirror 45. The surface roughness of the back surface of the substrate 21 can be controlled to have a root-mean-square (RMS) value of 3 nm or less. Alternatively, the surface roughness of the back surface of the substrate 21 may have an RMS value of 2 nm or less. In some embodiments ' it may have an RMS value of 1 nm or less. A method of manufacturing the distributed Bragg mirror 45 and the light emitting diode wafer will now be described. First, the surface roughness of the substrate 21 is controlled before the distributed Bragg mirror 45 is formed. For example, the back surface of the substrate 21 on which the light-emitting structure is formed is first ground to remove a portion of the substrate 21. In this case, the back surface of the substrate 21 is scratched by the grinding, so that it is relatively rough. Thereafter, the surface of the substrate 21 is aged with a slurry having small particles. In the buffing process, the depth of the groove (such as scratches in the surface of the substrate 21, etc.) is reduced, thereby reducing the surface roughness. In this case, the surface roughness of the back surface of the substrate 21 can be It is controlled to be smaller at 3 μιη by controlling the particle size of the diamond slurry used in the polishing process and the surface plate. However, in general, it is difficult to control the roughness of the surface using only the buffing process using the surface plate and the slurry particles. Therefore, after the surface roughness is reduced by the buffing process, the back surface of the substrate 21 can be polished by a chemical mechanical polishing (CMP) process. 13 201214780, the surface roughness of the back surface of the substrate 21 can be controlled to 1 nm or less by CMP process control. Then, a material layer having a different refractive index (e.g., Ti 2 , Si 2 , and Sis N 4 or the like) is alternately deposited on the surface of the substrate 21 . The deposition of these material layers can be carried out by different methods, such as sputtering electron beam deposition, plasma enhanced chemical vapor deposition (PECVD), etc. In particular, Ion-assisted deposition (i〇n is applied to the deposition). Ion-assisted deposition forms a layer of material of appropriate thickness by measuring the reflectivity of the layer of material deposited on the substrate 21, making it suitable for forming distributed Bragg reflections. The material layer of the mirror. After forming the distributed Bragg mirror, the metal layer can be formed on the distributed Bragg mirror. Thereafter, the substrate is diced to complete the individual light-emitting diode wafers. Figure 5 shows A cross-sectional view of a distributed Bragg mirror 55 of another exemplary embodiment of the present invention. The light emitting diode wafer according to the present exemplary embodiment is substantially similar to the light emitting diode wafer described with reference to FIGS. 3 and 4. Figures 3 and 4 show and illustrate that the distributed Bragg mirror 45 has a first distributed Bragg mirror 40 and a second distributed Bragg A stacked structure of the mirrors 50. On the other hand, in the distributed Bragg mirror 55 according to the present exemplary embodiment, a plurality of pairs of the first material layer 40a and the second material layer 40b and the plurality of pairs of the third material layers 50a and The fourth material layer 5〇b. In other words, 'at least a pair of the third material layer 50a and the fourth material layer 50b are disposed between the plurality of pairs of the first material layer 40a and the second material layer 40b. Further, at least 201214780 3751 〇pif A pair of first material layer 40a and first material layer 40b are placed between pairs of third material layers 50a and fourth material layers 50b. In this configuration, the first material layer 4〇a, second The optical thicknesses of the material layer 4〇b, the third material layer 5〇a, and the fourth material layer 5〇b are controlled to have a reflectivity for light in a wide range of visible light. Therefore, each constitutes a distributed Bragg reflection. The optical thicknesses of the material layers of the mirrors may be different from each other. Fig. 6 is a cross-sectional view of a light emitting diode wafer 20a having a plurality of light emitting units according to another exemplary embodiment of the present invention. The body wafer 20a includes a plurality of light emitting sheets on the substrate 21. Further, the light emitting diode chip 2A may include a distributed Bragg mirror 45 and a metal layer 51 and/or a protective layer 53. The substrate 21 and the distributed Bragg mirror 45 are similar to those of FIGS. 3, 4, and 5 The distributed Bragg mirror is illustrated, and thus its detailed description will be omitted. However, the substrate 21 may be an insulator that is electrically insulated from the plurality of light emitting units. For example, the substrate 21 may be a patterned sapphire substrate. A plurality of mutually isolated light emitting units 30. Each of the plurality of light emitting units 30 is the same as the light emitting structure 3A with reference to Fig. 3, and thus detailed description thereof will be omitted. In addition, the buffer layer 23 can be interposed between the light emitting unit 30 and the substrate 21, and the buffer layer 23 can also be isolated from each other. The first insulating layer 37 covers the front surface of the light emitting unit 3A. The first insulating layer 37 has an opening on the first conductive type semiconductor layer 25 and an opening on the second conductive type semiconductor layer 29. The side walls of the light emitting unit 3 are covered by the first insulating layer 37. The first insulating layer 37 also covers the substrate 21 in the region between the light-emitting units 3A. The first insulating layer 37 may be formed of a cerium oxide (Si 2 ) layer 15 201214780 or a silicon nitride layer, and may be a plasma chemical gas in a temperature range of 2 ° C to 300 ° C. Zhan formed by phase deposition. In this case, the first insulating layer 37 may be formed to have a thickness of 4500 A to 1 μm. When the first insulating layer is formed to have a thickness of less than 4500 people, a first insulating layer having a relatively small thickness may be formed due to a step coverage characteristic on the bottom side of the light emitting unit, and may be wired An electrical short circuit occurs between the wiring and the light emitting unit formed on the first insulating layer. Meanwhile, when the thickness of the first insulating layer becomes larger, an electrical short circuit can be prevented, but the transmittance of light may be deteriorated to reduce the luminous efficiency. Therefore, it is preferable to form the first insulating layer having a thickness of not more than 1 μm. At the same time, a wiring 39 is formed on the first insulating layer 37. The wiring 39 is electrically connected to the first conductive type semiconductor layer 25 and the second conductive type semiconductor layer 29 through the opening. The transparent electrode layer 31 may be disposed on the second conductive type semiconductor layer 29' and the wiring may be connected to the transparent electrode layer 31. Further, the wiring 39 is electrically connected to the first conductive type semiconductor layer 25 to the second conductive type semiconductor layer 29 of the adjacent light emitting units 30, respectively, so that a series array of the light emitting units 3A can be formed. Multiple series arrays can be formed and each connected in anti-parallel so that they can be connected to an alternating current (AC) power supply. In addition, a series of bridge rectifiers (not shown) connected to the lighting unit can be connected, and the lighting unit can be driven by the bridge rectifier under AC power. This bridge rectifier can be connected by a light-emitting unit having the same structure (e.g., the light-emitting unit 3 using the wiring 29). On the other hand, the wiring can connect the first conductive type semi-conducting semiconductors of the adjacent light-emitting units to the 201214780 37510pif single light. Therefore, the polymethalite which can be connected in _ and in parallel can be made of a conductor material (for example, a doped semiconductor material (such as a multi-39). In particular, it can be formed by a multi-layer structure; And a chrome or sharp upper layer. In addition, a metal layer of gold, gold or gold/chain may be interposed between the lower layer and the upper layer. (4) The f ^ insulating layer 41 may cover the wiring 39 and the first insulating layer 37. The second contact Q ^ Stops Wei gas or other similar pollution, and prevents, 'a light-emitting unit 30 from being damaged by an external impact. Hidden! Layer 41 can be the same material as the first insulating layer 37 and the oxygen-cut layer or the nitrogen-cut layer The second insulating layer 41 may be a layer formed by f chemical vapor deposition (10)c= at a temperature of lion ec to 3 〇〇C, similar to the first insulating layer. Further, when the first insulating layer When the borrower is formed by the PECVD method, the second insulating layer may be in the temperature range of ·2〇% to +2〇% of the deposition temperature of the first insulating layer, or may be in the same deposition. At the same time, when compared with the first insulating layer 37, the second insulating layer Μ Relatively thin 'and may have a thickness of 500 A or more. The second insulating layer 41 is thinner than the first insulating layer 37' to prevent the second insulating layer from being peeled off from the first. Further, when the second insulating layer is 2500 When the person is thin, it may be difficult to protect the wiring and the light-emitting unit from external impact or moisture penetration. 〃 At the same time, the light-weighting layer 43 may be placed on the light-emitting diode wafer. The phosphor layer 43 may be a resin dispersed in phosphorescence. Layer in the body or by electrophoresis
201214780 •J t X 圓7為用以綱根據本發明另—域性實施例的具有 夕個發光單元的發光二極體晶片20b的剖面圖。 參照® 7,㈣林紐實關的發光二健晶片2〇b 實質上與前面提及的發光二極體晶片咖類似，但它們在 發光單元30的形狀及接線39連接的第一導電型半導體層 25的部分的方面並不相同。 思即，發光二極體晶片20a的發光單元3〇具有第一 導電型半導體層25的暴露的上表面，而接線39連接至第 導電型半導體層25的上表面。與發光二極體晶片2〇a =同，根據本示範性實施例的發光二極體晶片2〇b的發光 單元30被形成而具有傾斜的側表面以暴露第一導電型半 導體層25的傾斜的側表面，而接線39連接至第一導電型 半導體層25的傾斜的側表面。 因此，根據本示範性實施例，除了分離發光單元的製 ，外’不需要進行暴露第-導電型半導體層25上部表面的 ，獨製程’藉此可簡化製程。另外，不需暴露第一導電型 半導體層25的上部表面，藉此可避免主動| 27的面積減 少。此外，由於接線39沿著第一導電型半導體層25的傾 斜的側表Φ連接’ g|此可改善發料元3G的電流散佈表 現’且因此，可減少正向電壓（f〇rwardv〇ltage)，並可改 善發光二極體晶片20b的可靠度。 實驗例201214780 • J t X Circle 7 is a cross-sectional view of a light-emitting diode wafer 20b having an illumination unit according to another embodiment of the present invention. Referring to ® 7, (4) Linnusuan's illuminating two-chip wafer 2〇b is substantially similar to the aforementioned light-emitting diode chip coffee, but they are in the shape of the light-emitting unit 30 and the first conductive type semiconductor connected by the wiring 39. Aspects of portions of layer 25 are not identical. It is to be understood that the light-emitting unit 3 of the light-emitting diode wafer 20a has the exposed upper surface of the first conductive type semiconductor layer 25, and the wiring 39 is connected to the upper surface of the first conductive type semiconductor layer 25. The light emitting unit 30 of the light emitting diode wafer 2〇b according to the present exemplary embodiment is formed to have an inclined side surface to expose the tilt of the first conductive type semiconductor layer 25, in the same manner as the light emitting diode wafer 2〇a= The side surface is connected, and the wiring 39 is connected to the inclined side surface of the first conductive type semiconductor layer 25. Therefore, according to the present exemplary embodiment, in addition to the process of separating the light-emitting units, it is not necessary to perform the process of exposing the upper surface of the first-conductivity-type semiconductor layer 25, whereby the process can be simplified. In addition, it is not necessary to expose the upper surface of the first conductive type semiconductor layer 25, whereby the area reduction of the active | 27 can be avoided. Further, since the wiring 39 is connected to 'g| along the inclined side surface Φ of the first conductive type semiconductor layer 25, this can improve the current dispersion performance of the emitting element 3G' and thus, the forward voltage can be reduced (f〇rwardv〇ltage ), and the reliability of the light-emitting diode chip 20b can be improved. Experimental example
18 (D 201214780 3751〇pif 圖8為顯示根據入射角的分佈式布拉格反射鏡的反射 率變化之模擬圖。在此情況中’分佈式布拉格反射鏡藉著 交替地在玻璃基底上堆疊40層的Si〇2與Ti02而製成。個 別控制每一個層的厚度而使得入射角度為〇。的4〇〇 nm至 700 nm的整個區域具有99%或更大的反射率。因此，分佈 式布拉格反射鏡整體厚度為2.908 μηι。同時，在實質上使 用的發光二極體晶片的情況中，入射角約為60。或者更大 角度的光入射會全部被反射，這是由於在藍寶石基底（η 約等於1.78)與Si02 (η約等於1.48)之間的折射率差異 所致，而因此，省略入射角為60。或者更大角度的模擬。 同時’圖8的圖顯示在反射率1〇〇%的部分的整個可見區 域（其類似於圖9中所示的圖）。 如由圖8的圖所能理解的，40層的分佈式布拉格反射 鏡關於在整個可見區域中〇。的入射角度而顯示99%或者更 高的超高反射率。然而，當入射至分佈式布拉格反射鏡的 光的入射角度增加，可理解長波長的可見光的反射率衰 減。當入射角度超過30。，對於7〇〇 nm波長的光的反射率 降至99%或者更低。 圖9A與圖9B分別顯示藉著增加分佈式布拉格反射鏡 的堆疊數來改善對於入射角度在5〇。及6〇。的長波長入射 光的反射率的實例。 參照圖9A及圖9B，如圖8中所說明，在分佈式布拉 格反射鏡具有40層（帆）而總厚度為2 9〇8啤的情況中， 對於入射角度50。的反射率（4〇L_5〇。）及對於入射角度6〇。 201214780 一》美 的反射率（40L-60。）比在長波長的可見區域中對於入射角 度〇的反射率（40L-0。）減少許多。此外，在可見區域的 中間區域（例如是在鄰近510 nm至520 nm)的部分發生 折射率衰減》 然而，當分佈式布拉格反射鏡的層的數目增加到48 層（總厚度：3·829 μιη)或52層（總厚度：4.367 μιη)時， 即使入射角大，亦可能獲得實質上在廣大波長區域内均勻 的南反射率。 因此，增加分佈式布拉格反射鏡的堆疊數目可以改善 反射率，並對於大入射角度的入射光維持高反射率。然而， 增加分佈式布拉格反射鏡的堆疊數目導致製程時間的增 加’且可能在分佈式布拉格反射鏡中會造成裂痕。 圖10Α與圖10Β分別為顯示在進行切割製程（dicing process)後的分佈式布拉格反射鏡的平面圖。在此情況 中，圖10A所示的情況為以離子輔助沈積方法堆疊4〇層 的分佈式布拉格反射鏡，而圖l〇B所示為以離子辅助沈積 方法堆疊48層的分佈式布拉格反射鏡。 當堆疊了 40層時（圖l〇A)，在分佈式布拉格反射 鏡中不會出現裂痕’而當堆疊了 48層時（圖10B)，在佈 式布拉格反射鏡中出現裂痕。當堆疊了 52層時（未繪示）， 同樣會出現裂痕。 在分佈式布拉格反射鏡中出現裂痕的原因並不清 楚但被§忍為與離子輔助沈積法有關。即，由於高密度的 層藉著離子對撞而沈積，壓力累積在分佈式布拉格反射鏡 201214780 3751ϋρΐί' :=因此在切割基底㈣，於分佈式布拉格反射鏡中會 現；痕。因此，可能不適合僅藉由增加堆疊數目來大量 製造發光二極體晶片。 與此理解有關，如圖3中所說明的，可在分佈式布拉 格反射鏡中形成反射金屬層，使得對於具有大入射角度的 光的相對高的反射率可以維持。 表1中顯示根據施加反射金屬層（Α1)與否在白色發 光二極體封裝體狀態中分佈式布拉格反射鏡的堆疊數目、 一種％氧化物及相對的發光效率。在這些實驗例中，除了 分佈式布拉格反射鏡、反射金屬層及環氧化物的類型之 外’其他條件（例如發光二極體的類型與封裝體的類型） 均相同。分佈式布拉格反射鏡的層的堆疊數目為40，而有 關未施加Α1反射金屬層（以"X"表示）的發光二極體晶片 的發光二極體封裝體（樣品1號）之發光效率以百分比（〇/〇) 表示。 21 201214780 表1 樣品編號 堆疊數目 施加反射金屬 層（A1) 環氧化物種類 — 相對發光致率（％) 1 40層 X 銀膠（SilverEpoxy) ----^ 100 2 40層 X 透明環氡樹脂 (Transparent Epoxy ) -^. 106.8 3 40層 0 銀膠 109.7 4 40層 0 透明環氧樹脂 108.6 5 48層 X 銀膠 106.4 6 48層 X 透明環氧樹脂 110.9~ 7 48層 0 銀膠 109.8 比敉诼而i兴保λ 2及橡品5與樣品6，當未施加 反射金屬層時，可知在發光效率依據所使用作為黏著齊 環氧化物的種類而有所不同。即，使用透明環氧樹脂的 品顯示出比使用銀膠的樣品高的發光效率。這顯示分饰 布拉格反射鏡的反射率在沒有A1反射金屬層存在 到黏著劑的影響。 同時’當使用同-種類的點著劑時，施加有Ai 金屬層的樣品（以，，◦”表示）顯示較其他樣品高的發夫 22 ⑤ 201214780 37510pif ^。例如’比較樣品i與樣品3、樣品2與樣品4及樣品$ 與樣品7，可知當施加A1反射金屬層時，發光效率改善。 同時，比較樣品1與樣品5及樣品2與樣品6，當使 用相同的黏著劑而未施加A1反射金屬層時，可知根據堆疊 數目的增加’發光效率改善。可理解分佈式布拉格反射鏡 堆疊數目的增加可改善在廣大入射角度範圍中分佈式布拉 格反射鏡的反射率，藉此造成發光效率的改善。 然而，比較樣品3與樣品7，當施加A1反射金屬層和 銀膠時，儘管堆疊數目增加，發光效率卻沒有差異。藉著 A1反射金屬層而對於具有大入射角度的長波長可見光維 持相對高的反射率。因此，當施加分佈式布拉格反射鏡和 反射金屬層時，可知當減少分佈式布拉格反射鏡的堆疊數 目時，在封裝體等級（package level)可達到良好的發光 效率。此外’分佈式布拉格反射鏡的堆疊數目減少可防止 在分佈式布拉格反射鏡中出現裂痕。 同時’當施加A1反射金屬層至分佈式布拉格反射鏡 時’可觀察到在晶片等級（chiplevel)的分佈式布拉格反 射鏡的反射率減少。此現象被認為與基底的表面粗糙度密 切相關。以下’將說明基底的表面粗糙度在晶片等級對於 分佈式布拉格反射鏡的反射率之影響。 圖11為顯示在使用銅表面平板的藍寶石基底磨光製 程後’根據是否進行CMP的分佈式布拉格反射鏡的反射 率之圖。 首先’在藍寶石基底的背面研磨之後，藉著使用具有 23 201214780 3 μπι的顆粒之鑽石研磨漿而進行使用銅表面平板的磨光 製，。在進行使用銅表面平板的磨光製程後，藍寶石基底 的背面之表面粗糙度顯示均方根值（RMS)在5 μιη Χ 5 μιη 的區域中約為5.12 nm。 其後，在藍寶石基底的背面經受CMp製程後，藉由 控制Τι〇2與Si〇2的厚度來形成前面所提及的第一分佈式 布拉格反射鏡和第二分佈式布拉格反射鏡以製造樣品（實 例1)。另一方面，比較例與實例丨類似，直接形成分佈 式布拉格反射鏡而不進行CMP製程以製造樣品。使用2〇 kg的量的Si〇2研磨漿進行CMP製程，而在CMP製程後， 藍寶石基底的表面粗链度於5 μιη X 5 μπι的區域中顯示約 0.25 nm 的 RMS 值。 在比較例的情況下，如圖1〇所示，在可見光範圍中 分佈式布拉格反射鏡顯示約90%或更大的反射率，但依據 波長的反射率不規則，且在鄰近550 nm處顯示90%或較 小的值。另一方面，在實例1中的情況，在可見光的廣大 波長範圍中，分佈式布拉格反射鏡大部分的反射率顯示接 近100%的值。 圖12為顯示約500 nm的鋁層沈積在與圖11中的實 例與比較例以相同方法製造的樣品上之後的反射率的圖。 在比較例的情況中，已確認在AI沈積之後，反射率 減少相當多。另一方面，在實例的情況中，即使在沈積A1 之後仍維持高反射率，而無反射率減少的情況。 在比較例中’被認為在A1沈積後才顯示出反射率減 ⑤ 24 201214780 37510pif 少的現象’這是因為在使用電子束沈積技術來沈積A1時， 根據比較例所形成在藍寶石基底上而具有粗縫表面的分佈 式布拉格反射鏡因界面缺陷而變形。在實例1的情況中， 因為藍寶石基底的表面粗缝度佳，已確認當A1沈積時，分 佈式布拉格反射鏡不變形而反射率維持。 圖13、圖14與圖15為顯示根據在使用錫表面平台的 磨光製程期間依研磨漿顆粒的尺寸的反射率圖。 在此種配置中，包含在鑽石顆粒中的研磨漿的尺寸與 鑽石顆粒分別為3 μιη、4 μιη與6 μηι。在使用錫表面平台 進行磨光製程後’根據鑽石顆粒尺寸，藍寶石基底的表面 粗糙度顯示的RMS值約2.40 nm、3.35 nm與4.18 nm。 在藉著錫表面平台進行磨光製程及沈積如圖8的實例 中500 nm的A1之後，形成與實例i相同的分佈式布拉格 反射鏡。 如由圖式中可理解的，在使用3 μιη的研磨漿與錫表 面平台進行磨光製程之後，在可見光範圍的廣大波長範圍 中，分佈式布拉格反射鏡的反射率為9〇%或更大。然而， 當沈積Α1時，在鄰近550 nm處的反射率猶微地減少。 相對地’如圖14與圖15所示’在使用4μιη4 6μιη 的研磨聚及錫表面平台進行磨光製程之後，在鄰近Mo nm 處分佈式布拉格反射鏡的反射率並未達到9〇%，且在沈積 A1之後，反射率降至80%或更低。 可由上述實驗例中理解，在分佈式布拉格反射鏡形成 之刖，藍寶石基底的表面粗輪度對於分佈式布拉格反射鏡 25 201214780 J /oiupif 的反射率有影響。此外，當控制藍寶石基底的表面粗糙度 使具有3 rnn或更小的RMS值時，相對地改善了反射特 性。此外’當藍寶石基底的表面粗糙度為1 nm或更小時， 可預期即使在沈積A1之後，反射率不會減少。 如由以上說明中顯而易知的，根據本發明的示範性實 施例’可提供在廣大波長範圍内具有高反射率的分佈式布 拉格反射鏡’以改善實施混合色光（如白光）的發光二極 體封裝體的發光效率。此外，亦可藉由控制其上形成有分 佈式布拉格反射鏡的基底的表面粗糙度確保分佈式布拉格 反射鏡的反射率。 對所屬技術領域中具有通常知識者而言，在不脫離本 發明的精神與範疇内，對本發明可進行不同的修正或更 動。因此，意為若本發明之修正或更動落在所附申請專利 範圍及其等效範圍内，本發明涵蓋之。 【圖式簡單說明】 為提供本發明進一步的理解而包含所附圖式，其併入 並構成此說明書的一部分，繪示本發明之實施例，並與說 明一併用以解釋本發明之原理。 '° 圖1為根據相關技術在藍寶石基底上形成紹的反 圖。 圖2為根據相關技術在藍寶石基底上的分佈 反射鏡的反射率圖。 圖3為根據本發明-示範性實施例的具有分 格反射鏡的發光二極體晶片的剖面圖。 大布拉 ⑤ 26 201214780 J/51Upif 圖4為圖3之分佈式布拉格反射鏡的放大剖面圖。 圖5為根據本發明另一示範性實施例的分佈式布拉格 反射鏡的剖面圖。 圖6為根據本發明另一示範性實施例的具有多個發光 單元的發光二極體晶片的剖面圖。 圖7為根據本發明另一示範性實施例的具有多個發光 單元的發光二極體晶片的剖面圖。 圖8為根據入射角的分佈式布拉格反射鏡的反射率變 化之模擬圖。 圖9A與圖9B分別為顯示藉著增加分佈式布拉格反射 鏡的堆疊數來改善對於入射角度在50。及60。的長波長入 射光的反射率的實例。 圖10A與圖10B分別為顯示在進行切割製程後的分佈 式布拉格反射鏡的平面圖。 圖11為顯示在使用銅表面平板的藍寳石基底磨光製 程後，根據化學機械研磨（CMP)的存在與否的分佈式布 拉格反射鏡的反射率圖。 圖12為顯示在以類似圖η的方法所製造的分佈式布 拉格反射鏡上沈積鋁反射金屬層後的反射率圖。 圖13、圖14與圖15為顯示在使用錫表面平台的磨光 製程期間根據研磨漿顆粒尺寸的反射率圖。 【主要元件符號說明】 20、20a、20b :發光二極體晶片 21 :基底 27 201214780. j / jiupxi 23 :緩衝層 25 :半導體層 27 :主動層 29 :半導體層 30 :發光結構（發光單元） 31 :透明電極層 33、35 :電極墊 37 :第一絕緣層 39 :接線 40 :第一分佈式布拉格反射鏡 40a :第一材料層 40b :第二材料層 41 :第二絕緣層 43 :磷光體層 45、55 :分佈式布拉格反射鏡 50:第二分佈式布拉格反射鏡 50a :第三材料層 50b :第四材料層 51 :金屬層 53 :保護層 ⑧18 (D 201214780 3751〇pif Figure 8 is a simulation showing the change in reflectivity of a distributed Bragg mirror according to the angle of incidence. In this case, the 'distributed Bragg mirrors are stacked 40 layers alternately on a glass substrate. Si〇2 and Ti02 are made. The thickness of each layer is individually controlled so that the incident angle is 〇. The entire region from 4 〇〇 nm to 700 nm has a reflectance of 99% or more. Therefore, distributed Bragg reflection The overall thickness of the mirror is 2.908 μηι. Meanwhile, in the case of a substantially used light-emitting diode wafer, the incident angle is about 60. Or a larger angle of light incidence is totally reflected, which is due to the sapphire substrate (η approximately Equal to 1.78) and SiO2 (η is approximately equal to 1.48) due to the difference in refractive index, and therefore, the angle of incidence is 60. or a larger angle of the simulation. Meanwhile, the graph of Figure 8 shows a reflectance of 1%. The entire visible area of the portion (which is similar to the one shown in Figure 9). As can be understood from the diagram of Figure 8, the 40-layer distributed Bragg mirror is about the angle of incidence of the entire visible region. display Ultra-high reflectance of 99% or higher. However, when the incident angle of light incident on the distributed Bragg mirror increases, it is understood that the reflectance of long-wavelength visible light is attenuated. When the incident angle exceeds 30., for 7〇〇 The reflectance of light at the nm wavelength is reduced to 99% or lower. Figures 9A and 9B show the improvement of the long-wavelength incidence for incident angles of 5 〇 and 6 借 by increasing the number of stacked Bragg mirrors, respectively. An example of the reflectance of light. Referring to Figures 9A and 9B, as illustrated in Figure 8, in the case where the distributed Bragg mirror has 40 layers (sail) and the total thickness is 2 9 〇 8 beer, for the incident angle 50 The reflectivity (4〇L_5〇.) and for the incident angle of 6〇. 201214780 The reflectivity of the US (40L-60.) is higher than the reflectance of the incident angle 〇 in the visible region of the long wavelength (40L-0. ) a lot less. In addition, the refractive index decay occurs in the middle of the visible region (for example, in the vicinity of 510 nm to 520 nm). However, when the number of layers of the distributed Bragg mirror is increased to 48 layers (total thickness: 3·829 Ιη) or 52 layers (total thickness: 4.367 μιη), even if the incident angle is large, it is possible to obtain a uniform south reflectance substantially over a wide wavelength region. Therefore, increasing the number of stacked Bragg mirrors can improve the reflectance. And maintain high reflectivity for incident light at large incident angles. However, increasing the number of stacked Bragg mirrors leads to an increase in process time' and may cause cracks in distributed Bragg mirrors. Figure 10Α and Figure 10, respectively To show a plan view of a distributed Bragg mirror after performing a dicing process. In this case, the case shown in FIG. 10A is a distributed Bragg mirror in which a 4 〇 layer is stacked by an ion-assisted deposition method, and FIG. 〇B shows a distributed Bragg mirror in which 48 layers are stacked by an ion-assisted deposition method. . When 40 layers are stacked (Fig. 1A), no cracks appear in the distributed Bragg mirrors, and when 48 layers are stacked (Fig. 10B), cracks appear in the Bragg mirrors. When 52 layers are stacked (not shown), cracks also occur. The cause of cracks in distributed Bragg mirrors is not clear but is related to ion assisted deposition. That is, since the high-density layer is deposited by ion collision, the pressure builds up in the distributed Bragg reflector 201214780 3751ϋρΐί' := Therefore, in the cutting substrate (4), it is found in the distributed Bragg mirror; Therefore, it may not be suitable to mass-produce a light-emitting diode wafer only by increasing the number of stacks. In connection with this understanding, as illustrated in Figure 3, a reflective metal layer can be formed in a distributed Bragg mirror such that a relatively high reflectance for light having a large angle of incidence can be maintained. Table 1 shows the number of stacked Bragg mirrors, a % oxide, and the relative luminous efficiency in the state of the white light-emitting diode package according to whether or not the reflective metal layer (?1) is applied. In these experimental examples, other conditions (e.g., the type of the light-emitting diode and the type of the package) were the same except for the types of the distributed Bragg reflector, the reflective metal layer, and the epoxide. The number of stacked layers of the distributed Bragg mirror is 40, and the luminous efficiency of the light-emitting diode package (sample No. 1) of the light-emitting diode chip to which the Α1 reflective metal layer (indicated by "X") is not applied Expressed as a percentage (〇/〇). 21 201214780 Table 1 Sample No. Stacking Number Applied Reflective Metal Layer (A1) Epoxide Type - Relative Luminescence Rate (%) 1 40 Layer X Silver Epoxy ----^ 100 2 40 Layer X Transparent Ring Resin (Transparent Epoxy ) -^. 106.8 3 40 layer 0 silver glue 109.7 4 40 layer 0 transparent epoxy resin 108.6 5 48 layers X silver glue 106.4 6 48 layers X transparent epoxy resin 110.9~ 7 48 layers 0 silver glue 109.8 敉When the reflective metal layer was not applied, it was found that the luminous efficiency differs depending on the type of the adhesive oxirane used. That is, a product using a transparent epoxy resin exhibited higher luminous efficiency than a sample using silver paste. This shows that the reflectivity of the sub-branched Bragg mirror is not affected by the adhesion of the A1 reflective metal layer. Meanwhile, 'when the same type of spotting agent is used, the sample to which the Ai metal layer is applied (indicated by ◦") shows a higher rate than other samples. 22 5 201214780 37510pif ^. For example, 'Comparing sample i with sample 3 , Sample 2 and Sample 4 and Sample $ and Sample 7, it is known that when the A1 reflective metal layer is applied, the luminous efficiency is improved. Meanwhile, Sample 1 and Sample 5 and Sample 2 and Sample 6 are compared, and the same adhesive is used without application. When A1 reflects the metal layer, it is known that the luminous efficiency is improved according to the increase in the number of stacks. It can be understood that the increase in the number of distributed Bragg mirror stacks can improve the reflectivity of the distributed Bragg mirror over a wide range of incident angles, thereby causing luminous efficiency. However, comparing Sample 3 with Sample 7, when the A1 reflective metal layer and the silver paste were applied, although the number of stacks was increased, there was no difference in luminous efficiency. Long-wavelength visible light having a large incident angle by the A1 reflective metal layer Maintaining a relatively high reflectivity. Therefore, when a distributed Bragg mirror and a reflective metal layer are applied, it is known that when distributed Bragg is reduced When the number of stacks of the mirrors is achieved, good luminous efficiency can be achieved at the package level. Furthermore, the reduction in the number of stacked Bragg mirrors prevents cracks in the distributed Bragg mirrors. When the metal layer is reflected to the distributed Bragg mirror, the reflectance of the distributed Bragg mirror at the chip level can be observed to decrease. This phenomenon is considered to be closely related to the surface roughness of the substrate. The effect of surface roughness on the reflectivity of the distributed Bragg mirror at the wafer level. Figure 11 is a graph showing the reflectance of a distributed Bragg mirror depending on whether CMP is performed after a sapphire substrate polishing process using a copper surface plate. First, after grinding on the back side of the sapphire substrate, polishing using a copper surface plate using a diamond slurry having particles of 23 201214780 3 μm. After performing a buffing process using a copper surface plate, sapphire The surface roughness of the back side of the substrate shows a root mean square (RMS) of 5 μιη The area of η Χ 5 μιη is about 5.12 nm. Thereafter, after the CMp process is performed on the back side of the sapphire substrate, the first distributed Bragg reflection mentioned above is formed by controlling the thickness of Τι〇2 and Si〇2. The mirror and the second distributed Bragg mirror were used to fabricate the sample (Example 1). On the other hand, the comparative example was similar to the example ,, directly forming a distributed Bragg mirror without performing a CMP process to manufacture a sample. Using an amount of 2 〇kg The Si〇2 slurry is subjected to a CMP process, and after the CMP process, the surface of the sapphire substrate exhibits an RMS value of about 0.25 nm in a region of 5 μm x 5 μm. In the case of the comparative example, FIG. As shown, the distributed Bragg mirror in the visible range shows a reflectance of about 90% or more, but the reflectance according to the wavelength is irregular, and a value of 90% or less is displayed adjacent to 550 nm. On the other hand, in the case of Example 1, in the broad wavelength range of visible light, most of the reflectance of the distributed Bragg mirror shows a value close to 100%. Fig. 12 is a graph showing the reflectance after deposition of an aluminum layer of about 500 nm on a sample fabricated in the same manner as the examples and comparative examples in Fig. 11. In the case of the comparative example, it has been confirmed that the reflectance is considerably reduced after the AI deposition. On the other hand, in the case of the example, the high reflectance is maintained even after the deposition of A1, and there is no case where the reflectance is reduced. In the comparative example, 'the phenomenon that the reflectance minus 5 24 201214780 37510pif is shown to be less after the deposition of A1 is considered' because the electron beam deposition technique is used to deposit A1, which is formed on the sapphire substrate according to the comparative example. The distributed Bragg mirror of the rough surface is deformed by interface defects. In the case of Example 1, since the surface roughness of the sapphire substrate was good, it was confirmed that when A1 was deposited, the distributed Bragg mirror was not deformed and the reflectance was maintained. Figures 13, 14 and 15 are graphs showing reflectance according to the size of the slurry particles during the buffing process using a tin surface platform. In this configuration, the size of the slurry contained in the diamond particles is 3 μηη, 4 μιη, and 6 μηι, respectively. After polishing with a tin surface platform, the surface roughness of the sapphire substrate shows an RMS value of about 2.40 nm, 3.35 nm, and 4.18 nm, depending on the diamond particle size. After the buffing process was performed by the tin surface platform and the A1 of 500 nm in the example of Fig. 8 was deposited, the same distributed Bragg mirror as in Example i was formed. As can be understood from the drawing, after using a 3 μm slurry and a tin surface platform for the polishing process, the distributed Bragg mirror has a reflectance of 9〇% or more in a wide wavelength range in the visible range. . However, when Α1 is deposited, the reflectance near 550 nm is slightly reduced. Relatively, as shown in Fig. 14 and Fig. 15, after the polishing process using a 4 μιη 4 6 μηη polished poly- and tin-surface platform, the reflectance of the distributed Bragg mirror near the Mo nm did not reach 9〇%, and After deposition of A1, the reflectance is reduced to 80% or less. It can be understood from the above experimental examples that the surface roughness of the sapphire substrate has an effect on the reflectivity of the distributed Bragg mirror 25 201214780 J /oiupif after the formation of the distributed Bragg mirror. Further, when the surface roughness of the sapphire substrate is controlled so as to have an RMS value of 3 rnn or less, the reflection characteristics are relatively improved. Further, when the surface roughness of the sapphire substrate is 1 nm or less, it is expected that the reflectance does not decrease even after the deposition of A1. As is apparent from the above description, an exemplary embodiment of the present invention can provide a distributed Bragg reflector having a high reflectance over a wide range of wavelengths to improve the implementation of a mixed color light (e.g., white light). The luminous efficiency of the polar body package. Furthermore, the reflectivity of the distributed Bragg mirror can also be ensured by controlling the surface roughness of the substrate on which the distributed Bragg mirror is formed. The invention may be variously modified or modified without departing from the spirit and scope of the invention. Therefore, it is intended that the present invention cover the modifications and the scope of the invention and the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in FIG '° Fig. 1 is an inverse view of the sapphire substrate formed according to the related art. Fig. 2 is a graph showing the reflectance of a distributed mirror on a sapphire substrate according to the related art. 3 is a cross-sectional view of a light emitting diode wafer having a lattice mirror in accordance with an exemplary embodiment of the present invention.大布拉 5 26 201214780 J/51Upif Figure 4 is an enlarged cross-sectional view of the distributed Bragg mirror of Figure 3. Figure 5 is a cross-sectional view of a distributed Bragg mirror in accordance with another exemplary embodiment of the present invention. FIG. 6 is a cross-sectional view of a light emitting diode wafer having a plurality of light emitting units, in accordance with another exemplary embodiment of the present invention. FIG. 7 is a cross-sectional view of a light emitting diode wafer having a plurality of light emitting units, in accordance with another exemplary embodiment of the present invention. Fig. 8 is a simulation diagram showing changes in reflectance of a distributed Bragg mirror according to an incident angle. Figures 9A and 9B show the improvement in incident angle at 50, respectively, by increasing the number of stacks of distributed Bragg mirrors. And 60. An example of the reflectivity of long wavelength incident light. 10A and 10B are plan views showing distributed Bragg mirrors after performing a cutting process, respectively. Figure 11 is a graph showing the reflectance of a distributed Bragg mirror according to the presence or absence of chemical mechanical polishing (CMP) after a sapphire substrate polishing process using a copper surface plate. Figure 12 is a graph showing the reflectance after depositing an aluminum reflective metal layer on a distributed Bragg mirror fabricated in a manner similar to Figure η. Figures 13, 14 and 15 are graphs showing the reflectance according to the particle size of the slurry during the buffing process using a tin surface platform. [Description of main component symbols] 20, 20a, 20b: Light-emitting diode wafer 21: Substrate 27 201214780. j / jiupxi 23: Buffer layer 25: Semiconductor layer 27: Active layer 29: Semiconductor layer 30: Light-emitting structure (light-emitting unit) 31: transparent electrode layer 33, 35: electrode pad 37: first insulating layer 39: wiring 40: first distributed Bragg mirror 40a: first material layer 40b: second material layer 41: second insulating layer 43: phosphorescent Body layer 45, 55: distributed Bragg mirror 50: second distributed Bragg mirror 50a: third material layer 50b: fourth material layer 51: metal layer 53: protective layer 8