1254469 九、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晶片，特別是一種薄膜發光 二極體晶片。 【先前技術】 由 Y. C. Shen 等多人之文件 ” Optical cavity effects in InGaN/GaN quantum-well-heterostructure flip-chip light-emitting diodes’’，Appl· Phys· Lett· Vol· 82 No. 14. ® P.222 1中已知一種以GaN爲主之FCLED-晶片（以覆晶 (0^<1111))配置而成的發光二極體晶片）。該處是以藍寶石-基板作爲一種發射層。 由文件US 2003/0 143772 A1中已知一種薄膜發光二極體 晶片，其具有一種未具備生長基板的AlGalnN磊晶構造。 【發明內容】 本發明的目的是提供一種薄膜發光二極體晶.片，其具有 高的效率和低的吸收損耗。 一種薄膜發光二極體晶片，其中鏡面層和光產生用的活 性層之間之距離須調整，使一種由活性區所發出的輻射可 _ 受到由鏡面層所反射的光所干擾。藉由此種干擾，則活性 區之內部之量子效率會受到影響而使活性區達到一種與方 向有關的發射特性。此種與方向有關的發射特性具有至少 一種優先方向。該薄膜發光二極體晶片具有一種發射層， 其至少是半導電性者。該發射層因此不是一種去（de-)反射 1254469 薄膜發光二極體晶片之特徵特別是以下各點： ^ -在輻射產生用的磊晶層序列之一種面向載體元件之 ’ 一主面上施加或形成一種反射層，其使幕晶層序列中所 生的電磁輻射之至少一部份反射回到嘉晶層序列中； -磊晶層序列之厚度是在2 0微米或更小的範圍中，特 是在4微米和1 〇微米之間， -磊晶層序列包含至少一種半導體層，其至少一 (plane)具備一混合結構，該混合結構在理想情況下會使 晶之嘉晶層序列中的光形成一種近似隨機（ergodic)的 佈，即，使光具有一種儘可能隨機的雜散特性。 薄膜發光二極體晶片在較佳的近似情況中是一種蘭佈 (Lambertic)表面發射器。薄膜發光二極體晶片之基本原 例如已描述在I. Schnitzer等多人於Appl· Phys. Lett. (16)，18· October 1993，2174-2176 發表的文件中。 所謂薄膜發光二極體晶片目前特別是指一種發光二極 晶片，其一種層結構具有以磊晶生長之層，生長基板在 胃長過程之後較佳是由該層結構中去除。以磊晶生長之層 至少一部份是半導體層。晶片可具有一種與生長基板不 的載體，載體上施加該層結構。 上述之薄膜發光二極體晶片未具有共振器。相對 RCLED (Resonant Cavity Light Emitting Diode)而言，上 之薄膜發光二極體晶片只包含唯一的鏡面。該薄膜發光 極體晶片且特別是磊晶之層結構相對於RCLED而言有利 未包含佈拉格（Bragg)鏡面。 第 產 別 面 嘉 分 德 理 63 am 體 生 之 同 於 述 地 1254469 在一種較佳的形式中，薄膜發光二極體晶片以G aN爲 主。相對於藍寶石基板上之以GaN爲主之覆晶（Flip Chip) ^ 發光二極體而言，半導體本體中所產生的光直接（即，無吸 收損耗和反射損耗）由於一種配置在輻射發射用的磊晶層序 列之後的基板而由半導體本體中射出。 薄膜發光二極體晶片中光學近場效應大大地影響了發射 效率。使用光學近場效應的優點是可使光產生用的半導體 所發出的輻射成份提高。此處所提及的薄膜晶片之特徵是 ® 一種高的發射效率，其可超過70%。 活性區通常具有多個部份層，其形式例如是一種單一量 子井結構或多重量子井結構。 半導體本體具有至少一第一導電型式的第一半導體層， 至少一第二導電形式的第二半導體層以及一配置在此二種 半導體層之間的活性區。第一半導體層較佳是p-摻雜者， 第二半導體層較佳是η-摻雜者。半導體層較佳是透明的， 即，其可透過活性區中所產生的輻射。 β 半導體本體例如可包含一種阻障層，其配置在第一半導 體層和鏡面層之間且例如作爲電荷載體擴散阻障用，即， 使電荷載體在鏡面層的方向中不能由第一半導體層移動出 來。電荷載體-阻障層較佳是其至少一部份是半導電性者且 在另一種形式中可包含鋁。電荷載體-阻障層較佳是可透過 該活性區中所產生的輻射。 半導體本體較佳是與晶片之以磊晶生長的層結構相同。 半導體本體的各層生長在生長基板上，該生長基板以晶圓 -7- 1254469 形式而存在著。首先，η -摻雜的第二半導體層較佳是以磊晶 方式沈積而成。然後，活性區或活性區的部份層，ρ _摻雜的 第一半導體層且情況需要時一種電荷載體-阻障層依序以磊 晶方式生長。隨後較佳是藉由濺鍍或蒸鍍而塗佈該鏡面層。 鏡面層較佳是一種金屬層。鏡面層較佳是寬能帶者且具 有高的反射性，其中該鏡面層例如可使入射的光之至少 70 % (較佳是至少80 % )被反射。鏡面層例如由Ag，Au，Pt或 A1及/或由這些金屬之至少二種之合金所產生。鏡面層亦可 以是一種多層序列，其具有的多個層是由上述各種不同的 金屬或合金所形成。 層複合物包含磊晶層序列，生長基板和鏡面層。層複合 物較佳是藉由共晶的鍵結（Bonding)而與載體固定地相連 接，載體就電性及/或熱性而言可被最佳化且就其光學特性 而言不需設定任何需求。載體較佳是具有導電性或至少是 半導電性者。例如，鍺，GaAs，SiC，.A1N或矽適合作爲載體 材料。載體之面向鏡面層之表面較佳是成平坦狀。該生長 基板在層複合物與載體相連接之後由半導體本體中剝除。 在鏡面層和載體之間可設置至少一黏合促進層。較佳是 導電性的黏合促進層使載體與磊晶-層序列相連接，其中該 鏡面層面向載體。該黏合促進層特別是可爲一種由p b S η (焊 劑），AuGe，AuBe，AuSi，Sn，In或Pdln所構成的金屬層。鏡 面層可藉由一種面向黏合促進層之擴散阻障層（其例如包含 鈦及/或鎢）而受到保護。一擴散阻障層可使材料不會由黏合 促進層侵入至鏡面層中。 1254469 此處所述的發光二極體晶片之全部的層，特別是活性區 ^ 和半導體本體的半導體層，可分別由多個部份層所構成。 — 半導體本體包含一種具有發射面的發射層。發射層中的 輻射分佈具有多個優先方向。該發射層較佳是與第二半導 體層（其例如是η-摻雜者）相同。第一半導體層（其例如是p-摻雜者）較佳是配置在鏡面層和活性區之間。 鏡面層須靠近光源（即，活性區）而配置，使干擾發生時光 學近場效應顯著。藉由所產生的光源和已反射的光源之間 ^ 的干擾，則活性區中自發的發射會受到影響，特別是發射 用的組合作用的壽命會受到影響且因此使光產生用的層中 的內部量子效率受到影響。至活性區的特定的鏡面距離（例 如，λ/4, 3λ/4, 5λ/4)產生一種有利的（與角度有關之）發射特 性，此種特定的鏡面距離隨著內部量子效率之提高而出現。 鏡面和光源之間的距離例如最大是2λ，其中λ = λ〇/η是光 學介質（此處是半導體本體）中的光波長且λ〇是真空中的光 波長。光產生用的層和鏡面層之間的距離在本實施形式中 胃小於1·75λ。在另一有利的形式中此種距離小於1·5λ。較小 的距離的優點是：藉由活性區中所產生的輻射和鏡面層中 所反射的輻射的交互作用，則可控制該活性區之自發的發 射作用。 由光源所產生的輻射和由鏡面所反射的輻射在光源和鏡 面之間處於特定的距離時可形成建設性的干涉。例如，當 光源和鏡面之間的距離是（2m+ 1 )λ/4η，其中η是光學介質之 折射率且m = 0，1，2...是發射的階數（order)時，則在垂直於 -9 - 1254469 光學介質之界面而入射的輻射中該輻射分佈會發生最大 〜 値。在第零階（order)發射時，全部的光子在一種錐體（其旋 > 轉對稱軸垂直於發射界面）中發射。在第一階發射時存在著 另外的發射特性，其對該發射面的垂線具有較大的角度。 在第m階發射時存在著m個此種另外的發射特性。 藉由調整光產生用的層和鏡面層之間的距離（其是 (2ιη+1)λ/4)，則可使活性區達成一種已對準的發射特性，其 與蘭佈德（Lamb eftic)發射特性不同且具有一種高強度和低 ® 強度交互配置的區域。須選取該鏡面至光產生用的層之距 離且因此亦須調整半導體內部中的發射特性，使得在第一 次入射至光射出用的界面時一種高的輻射成份即已存在於 較全反射的臨界角還小的範圍中。 鏡面層和活性區之間的距離在不同的實施形式中例如可 爲： 1) 0·16λ至0·28λ，即，大約λ/4 ;該輻射分佈具有一種 優先方向，其垂直於發射面； ® 2) 0.63λ至0·7 8λ，即，大約3λ/4 ;該輻射分佈具有二種 優先方向，即，一與發射面垂直的方向和一與其成傾斜的 方向； 3) 1·15λ至1·38λ，即，大約5λ/4;該輻射分佈具有三種 優先方向，即，一與發射面垂直的方向和二種與其成傾斜 的方向。 已發出的輻射之波長可位於紅外光區，可見光區或紫外 光區中。半導體本體可依據波長而以不同的半導體材料系 -10- 1254469 統爲基準以製成。例如，一種以InxGayAh + yAs爲主的半 ， 導體本體適用於長波長的輻射，以IrixGayAh-x-yP爲主的半 ^ 導體本體適用於可見之紅色至黃色的輻射，以 ItixGayAl^x-yN爲主的半導體本體適用於短波長之可見之 (綠色至藍色）輻射或紫外線（UV)輻射，其中0$ 1且 1。發出的輻射之光譜寬度例如可爲15至40 nm。但 所產生的輻射之光譜之半値寬度不限於上述之範圍。 光產生用之層和該鏡面層之間的距離較佳是與p -層之層 β厚度相同。 第二半導體層在另一實施形式中可具有一種平坦的發射 面。由晶片所發出的光的發射特性在此種情況下與蘭佈德 (Lamb ertic)發射特性不同且在至少一優先的方向中具有較 高的輻射密度，而在其它的角度範圍中具有小的輻射密度。 在另一實施形式中，須構成第二半導體層之發射面，使 得在入射至界面上時未射.出的輻射可在不同的方向中散射 回到半導體中。藉由輻射方向的重新分佈，則可防止一種 所謂波導效應，且因此使發射效率提高。由晶片所發出的 輻射之發射特性在此種情況下基本上具有蘭佈德 (L a m b e r t i c)發射特性。 第二半導體層可配置在活性區和去反射層之間，該去反 射層之厚度大約與波長的四分之一相等。去反射層較佳是 一種介電質層，其在該生長基板去除之後施加在半導體本 體的發射面上。 發光二極體晶片在光電組件中較佳是配置在一種外殼之 -11- 1254469 凹口中，其中該凹口可具有一種反射用的表面。發光 體晶片在該凹口中可以一種澆注物質來包封。藉由使 折射率的樹脂（例如，環氧樹脂或矽樹脂，其折射率η 1 · 5 5 )來包封該薄膜晶片，則可使光學組件的發射效率击 本發明以下將依據圖式和實施例來描述。各圖式未 比例大小來顯示本發明的不同之實施例。相同-或作用 的零件以相同的參考符號來表示。 【實施方式】 第1圖顯不薄膜發光二極體晶片100之一部份，其 載體6和一種多層構造1 〇。載體6和多層構造1 0之間 ~^種黏合促進層5。該多層構造10包含一種光產生用 性區3，其配置在ρ-導電之第一半導體層1和η-導電 二半導體層2之間。第一半導體層1配置在活性區3 屬性的鏡面層4之間。導電的鏡面層4作爲鏡面用且 爲至第一半導體層之電性接觸層。鏡面層4受到擴散 層45所保護，該層45配置在鏡面層4和黏合促進層 間。第一和第二半導體層1和2以及活性區3 —起形 導體本體123。半導體本體123 —起與擴散阻障層45 面層4形成多層構造10。 在上述薄膜發光二極體晶片之製造方法中，在此處 示的生長基板上依序以磊晶方式產生第二半導體層2, 區3和第一半導體層1。在該磊晶-層構造上例如藉由 或蒸鍍而施加該鏡面層4。該多層構造1 〇藉由黏合促 5而與載體6相連接，載體6例如由鍺所構成或以鍺爲 二極 用高 大於 I高。 依據 相同 具有 配置 的活 之第 和金 亦作 阻障 5之 成半 和鏡 未顯 活性 濺鍍 進層 主要 -12- 1254469 成份。然後去除該生長基板。面對該生長基板之第二半導 體層2在該基板去除之後形成一種發射層且該發射層之遠 離該活性區3之表面形成一種發射面20，其在本實施例中 是平坦的。 活性區3中所產生的輻射和鏡面層4所反射的輻射之擴 散方向在第1圖中以箭頭7或8來表示。由該二種輻射成 份7和8之干涉所產生的光在遠離載體6的方向中由多層 構造1 0射出。 須調整鏡面層4和活性區3之間的距離（其在本形式中等 於第一半導體層1之厚度），使由活性區3所發出的輻射可 受到鏡面層4所反射的輻射所干擾，且活性區3中發射用 的組合作用的壽命會受到此種干擾所影響。 上述的薄膜發光二極體晶片中所使用的近場效應可與一 種空腔（cavity)效應相比擬，所謂空腔是指一種光學共振器 (共振空腔）中所產生的波動效應。藉由此種效應，則光產生 用的半導體內部中可調整其發射特性，使光子的大部份都 可射入至該射出用的界面上的一種角度中，該角度小於全 反射的角度。因此，該輻射的最大可能的部份在第一次入 射至該射出用的界面（=發射面20)上時由該晶片射出。只有 一小部份反射回到半導體1，2，3中。光的此一小部份在 鏡面層4上反射時會造成損耗且在其又入射至射出用的界 面上之前亦會由於活性區3中的再吸收（其量子效率只有大 約50%)而造成損耗。因此，薄膜發光二極體晶片中藉由使 用上述的空腔效應，則可使再循環速率（Recycling rate)大 -13- 1254469 大地下降。 > 薄膜發光二極體中藉由使用上述空腔效應的其它優點是 < 半導體外部中發射特性會受到影響。依據半導體內部中光 子之角度分佈相對於鏡面和光產生用的層之間的距離之關 係，則在一種未粗糙化的發射面中可使半導體外部之發射 特性改變且特別是可達成一種具有優先方向的輻射分佈。 該光產生用的層至鏡面層的距離d之較佳之値是針對該 波長λ〇 = 4 5 5 nm (對應於折射率n = 2.5之半導體本體中之波 ^ 長λ=182 nm)之輻射而言。對所發出的第零階之輻射而言， d = 40 nm。對所發出的第一階之輻射而言，d=130 nm。對所 發出的第二階之輻射而言，d = 230 nm。 上述的各値在第零階時對應於（1 = 0.22λ，在第一階時對應 於d = 0.7 1X，且在第二階時對應於ο!=1.26λ。就其它的波長 而言，d須相對應地調整。 發射的階數越小，則薄膜發光二極體晶片之效率越高。 例如，當由第二階的發射轉換至第一階的發射時，則效率 ® 增加25 %。在較佳的實施形式中因此須調整第零階的發射。 以GaN爲主的薄膜發光二極體晶片之適當的具體構成具 有以下的層序列： -前側-接觸金屬層 -高摻雜的GaN:Si (層厚度700- 1 500 nm) -較低摻的GaN:Si (層厚度4000 nm) -未摻雜的GaN (層厚度30 nm) -InGaN-量子井（層厚度：大約1 nm; In含量大約10%) -14- 1254469 -阻障層（大約5nm未摻雜的GaN + 6-7 nm矽摻雜的GaN + 大約5 n m未摻雜的G a N ) -InGaN-量子井如上 -阻障層如上 -InGaN-量子井如上 -阻障層如上 -InGaN-量子井（層厚度：大約2-3 nm; In含量大約20%) -未摻雜的GaN(層厚度5-10 nm) - p-摻雜的AlGaN-層（層厚度20-40 nm; 電子-阻障層；鋁含量10-25%) - P-摻雜的GaN:Mg (終端層） -鏡面（Pt-層未閉合+Ag-層+擴散阻障+情況需要時其它 的層+連接層） -鍺-載體 在第2圖的第二實施例中，其與第1圖的實施例不同之 處是：在活性區3和面向鏡面層4之半導體層（即，第一半 導體層1)之間較佳是配置至少另一薄的電荷載體-阻障層 11。電荷載體-阻障層11較佳是半導體本體之一種成份且因 此以磊晶方式生長而成以及具有半導電性。 此外，在第2圖的實施例中，在第二半導體層2上設有 一種鈍化層8，其藉由某種大小的厚度調整至一適當的形式 而形成一種去反射層，其可在該生長基板去除之後例如藉 由沈積過程施加而成。該去反射層8不是以磊晶方式產生 且例如由氧化砂或氮化砍所構成。 -15- 1254469 第3圖之薄膜發光二極體晶片之實施例具有一種已粗糙 _ 化的發射面20，這與第2圖之實施例不同。藉由使用空腔 ^ 效應所達成的增益因此只會微不足道地減弱。發射特性只 微不足道地受到活性區至鏡面之距離變動所影響，這樣是 有利的。 第4圖中顯示一種光學元件，其例如依據第1至3圖中 所示的實施例而包含一種具有外殼的發光二極體晶片 100。發光二極體晶片100安裝在導線架92上且建構在該 ^ 外殻91的凹口中。外殼91的凹口較佳是具有一種光反射 用的表面。發光二極體晶片以澆注物質9 0來包封。 本發明當然不限於依據各實施例所作的描述之範圍。反 之，本發明包含每一新的特徵以及各特徵的每一種組合， 其特別是包含不同的申請專利範圍-或不同的實施例之各別 的特徵之每一種組合，當相關的特徵或相關的組合本身未 明顯地顯示在各申請專利範圍中或各實施例中時亦同。 【圖式簡單說明】 第1圖具有平坦之發射面之薄膜發光二極體晶片之一例。 第2圖具有半導體本體（其包含一種阻障層）和去反射層之薄 一 膜發光二極體晶片。 第3圖具有已構成的發射面之薄膜發光二極體晶片。 第4圖具有發光二極體晶片之光學組件。 【元件符號說明】 100 發光二極體晶片 10 多層構造 -16- 12544691254469 IX. Description of the Invention: _ Technical Field of the Invention - The present invention relates to a light-emitting diode wafer, and more particularly to a thin film light-emitting diode wafer. [Prior Art] A document by YC Shen et al. "Optical cavity effects in InGaN/GaN quantum-well-heterostructure flip-chip light-emitting diodes'', Appl· Phys· Lett· Vol· 82 No. 14. ® P A GaN-based FCLED-wafer (a photodiode wafer configured by flip-chip (0^<1111)) is known as a sapphire-substrate as an emissive layer. A thin film light-emitting diode wafer having an AlGalnN epitaxial structure without a growth substrate is known from the document US 2003/0 143 772 A1. SUMMARY OF THE INVENTION The object of the present invention is to provide a thin film light-emitting diode crystal. a film having high efficiency and low absorption loss. A thin film light-emitting diode wafer in which the distance between the mirror layer and the active layer for light generation is adjusted so that a radiation emitted from the active region can be subjected to The light reflected by the mirror layer interferes. By this interference, the quantum efficiency of the interior of the active region is affected and the active region reaches a direction-dependent emission characteristic. The film has at least one preferential direction. The thin film light emitting diode wafer has an emissive layer which is at least semiconducting. The emissive layer is therefore not a de-reflective 1254469 thin film light emitting diode chip, especially The following points: ^ - applying or forming a reflective layer on one of the major faces of the carrier element of the epitaxial layer sequence for radiation generation, which causes at least a portion of the electromagnetic radiation generated in the sequence of the curtain layer Reflecting back into the sequence of the mesa layer; - the thickness of the epitaxial layer sequence is in the range of 20 micrometers or less, especially between 4 micrometers and 1 micrometer, and the epitaxial layer sequence comprises at least one semiconductor layer At least one of the planes has a hybrid structure which ideally causes the light in the sequence of the crystal layer to form an approximately ergodic cloth, that is, to make the light as random as possible. The stray characteristics of the thin film light-emitting diode wafer is a lamber surface emitter in a preferred approximation. The basic principle of the thin film light-emitting diode wafer has been described, for example, in I. Schnitzer et al. Many people in the document published by Appl. Phys. Lett. (16), 18· October 1993, 2174-2176. The so-called thin-film light-emitting diode wafer currently refers in particular to a light-emitting diode chip, which has a layer structure with In the layer of crystal growth, the growth substrate is preferably removed from the layer structure after the gastric length process. At least a portion of the layer grown by epitaxial growth is a semiconductor layer. The wafer may have a carrier that is not associated with the growth substrate, and the layer structure is applied to the carrier. The thin film light-emitting diode wafer described above does not have a resonator. In contrast to RCLED (Resonant Cavity Light Emitting Diode), the upper thin film LED array contains only a single mirror surface. The thin-film light-emitting body wafer and in particular the epitaxial layer structure advantageously does not comprise a Bragg mirror surface with respect to the RCLED. The first aspect of the product is divided into the same as that of the ground. 1254469 In a preferred form, the thin film light-emitting diode wafer is dominated by G aN. Compared with the GaN-based Flip Chip ^ light-emitting diode on the sapphire substrate, the light generated in the semiconductor body is directly (ie, no absorption loss and reflection loss) due to a configuration for radiation emission. The substrate after the epitaxial layer sequence is emitted from the semiconductor body. The optical near-field effect in thin film light-emitting diode wafers greatly affects the emission efficiency. The advantage of using an optical near-field effect is that the radiation component emitted by the semiconductor for light generation can be increased. The thin film wafer mentioned here is characterized by a high emission efficiency which can exceed 70%. The active region typically has a plurality of partial layers in the form of, for example, a single quantum well structure or a multiple quantum well structure. The semiconductor body has at least a first semiconductor layer of a first conductivity type, at least a second semiconductor layer of a second conductivity type, and an active region disposed between the two semiconductor layers. The first semiconductor layer is preferably a p-doped, and the second semiconductor layer is preferably an n-doped. The semiconductor layer is preferably transparent, i.e., it is permeable to radiation generated in the active region. The beta semiconductor body can, for example, comprise a barrier layer which is arranged between the first semiconductor layer and the mirror layer and serves, for example, as a charge carrier diffusion barrier, ie the charge carrier cannot be in the direction of the mirror layer from the first semiconductor layer. Move it out. Preferably, the charge carrier-barrier layer is at least partially semi-conductive and in another form may comprise aluminum. The charge carrier-barrier layer is preferably permeable to radiation generated in the active region. The semiconductor body is preferably the same as the layer structure of the wafer which is epitaxially grown. The layers of the semiconductor body are grown on a growth substrate that is in the form of wafer -7 - 1254469. First, the η-doped second semiconductor layer is preferably deposited in an epitaxial manner. Then, a partial layer of the active or active region, a p-doped first semiconductor layer and, if desired, a charge carrier-barrier layer is sequentially grown in an epitaxial manner. The mirror layer is then preferably applied by sputtering or evaporation. The mirror layer is preferably a metal layer. The mirror layer is preferably a wide band and has a high reflectivity, wherein the mirror layer, for example, allows at least 70% (preferably at least 80%) of the incident light to be reflected. The mirror layer is produced, for example, from Ag, Au, Pt or A1 and/or from at least two alloys of these metals. The mirror layer can also be a multilayer sequence having a plurality of layers formed from the various metals or alloys described above. The layer composite comprises an epitaxial layer sequence, a growth substrate and a mirror layer. The layer composite is preferably fixedly bonded to the carrier by eutectic bonding, the carrier can be optimized in terms of electrical and/or thermal properties and does not need to be set in terms of its optical properties. demand. The carrier is preferably one having electrical conductivity or at least semiconducting. For example, yttrium, GaAs, SiC, .A1N or yttrium is suitable as a carrier material. The surface of the carrier facing the mirror layer is preferably flat. The growth substrate is stripped from the semiconductor body after the layer composite is attached to the carrier. At least one adhesion promoting layer may be disposed between the mirror layer and the carrier. Preferably, the electrically conductive adhesion promoting layer connects the carrier to the epitaxial layer sequence, wherein the mirror layer faces the carrier. The adhesion promoting layer may in particular be a metal layer composed of p b S η (solder), AuGe, AuBe, AuSi, Sn, In or Pdln. The mirror layer can be protected by a diffusion barrier layer facing the adhesion promoting layer, which for example comprises titanium and/or tungsten. A diffusion barrier layer prevents the material from intruding into the mirror layer by the adhesion promoting layer. 1254469 All of the layers of the light-emitting diode wafer described herein, particularly the active region ^ and the semiconductor layer of the semiconductor body, may each be composed of a plurality of partial layers. – The semiconductor body comprises an emissive layer having an emitting surface. The radiation distribution in the emissive layer has multiple preferential directions. The emissive layer is preferably the same as the second semiconductor layer (which is, for example, an n-doped). The first semiconductor layer (which is, for example, a p-doping) is preferably disposed between the mirror layer and the active region. The mirror layer must be placed close to the source (i.e., the active region) to provide significant near-field effects when interference occurs. By the interference between the generated light source and the reflected light source, spontaneous emission in the active region is affected, in particular, the lifetime of the combined action for emission is affected and thus in the layer for light generation Internal quantum efficiency is affected. The specific specular distance to the active region (eg, λ/4, 3λ/4, 5λ/4) produces an advantageous (angle-dependent) emission characteristic that increases with internal quantum efficiency. appear. The distance between the mirror and the source is, for example, at most 2λ, where λ = λ 〇 / η is the wavelength of light in the optical medium (here the semiconductor body) and λ 〇 is the wavelength of light in the vacuum. The distance between the layer for light generation and the mirror layer is less than 1.75 λ in the present embodiment. In another advantageous form such distance is less than 1·5λ. The advantage of a smaller distance is that the spontaneous emission of the active region can be controlled by the interaction of the radiation generated in the active region with the radiation reflected in the mirror layer. The radiation generated by the light source and the radiation reflected by the mirror form constructive interference when the light source and the mirror are at a specific distance. For example, when the distance between the light source and the mirror is (2m + 1) λ / 4η, where η is the refractive index of the optical medium and m = 0, 1, 2... is the order of the emission, then This radiation distribution occurs at a maximum of ~ 値 in the incident radiation perpendicular to the interface of the -9 - 1254469 optical medium. At the zeroth order emission, all photons are emitted in a cone whose spin axis & symmetry axis is perpendicular to the emission interface. There is an additional emission characteristic at the first order of emission which has a larger angle to the perpendicular of the emitting surface. There are m such additional emission characteristics at the mth order emission. By adjusting the distance between the layer for light generation and the mirror layer (which is (2ιη+1) λ/4), the active region can be achieved with an aligned emission characteristic, which is compatible with Lamb eftic. ) A region with different emission characteristics and an alternating configuration of high intensity and low intensity. The distance from the mirror to the layer for light generation must be chosen and therefore the emission characteristics in the interior of the semiconductor must also be adjusted so that a high radiation component is already present in the more total reflection at the first incident to the interface for light exit. The critical angle is also small. The distance between the mirror layer and the active region can be, for example, in different embodiments: 1) 0·16λ to 0·28λ, ie approximately λ/4; the radiation distribution has a preferential direction which is perpendicular to the emission surface; ® 2) 0.63λ to 0·7 8λ, ie, approximately 3λ/4; the radiation distribution has two preferential directions, ie a direction perpendicular to the emitting surface and a direction inclined thereto; 3) 1·15λ to 1·38λ, that is, about 5λ/4; the radiation distribution has three preferential directions, that is, a direction perpendicular to the emitting surface and two directions inclined thereto. The wavelength of the emitted radiation can be in the infrared, visible or ultraviolet region. The semiconductor body can be made based on different wavelengths of the semiconductor material system -10- 1254469. For example, a half dominated by InxGayAh + yAs, the conductor body is suitable for long-wavelength radiation, and the semi-conductor body based on IrixGayAh-x-yP is suitable for visible red to yellow radiation, with ItixGayAl^x-yN The main semiconductor body is suitable for visible (green to blue) radiation or ultraviolet (UV) radiation of short wavelengths, where 0$ 1 and 1. The spectral width of the emitted radiation can be, for example, 15 to 40 nm. However, the half width of the spectrum of the generated radiation is not limited to the above range. The distance between the layer for light generation and the mirror layer is preferably the same as the thickness of the layer β of the p-layer. The second semiconductor layer may have a flat emitting surface in another embodiment. The emission characteristics of the light emitted by the wafer are different in this case from the Lambert's emission characteristics and have a higher radiation density in at least one preferential direction and a smaller in other angular ranges. Radiation density. In a further embodiment, the emitting surface of the second semiconductor layer has to be formed such that unexposed radiation can be scattered back into the semiconductor in different directions when incident on the interface. By the redistribution of the radiation direction, a so-called waveguide effect can be prevented, and thus the emission efficiency is improved. The emission characteristics of the radiation emitted by the wafer in this case essentially have a Lamb's emission characteristic. The second semiconductor layer can be disposed between the active region and the de-reflective layer, the thickness of the de-reflective layer being approximately equal to one-quarter of the wavelength. The antireflection layer is preferably a dielectric layer which is applied to the emission surface of the semiconductor body after the growth substrate is removed. The light-emitting diode wafer is preferably disposed in the optoelectronic component in a recess of the outer casing -11 - 1254469, wherein the recess may have a reflective surface. The illuminant wafer can be encapsulated in the recess by a potting material. By encapsulating the thin film wafer by a resin having a refractive index (for example, an epoxy resin or a ruthenium resin having a refractive index η 1 · 5 5 ), the emission efficiency of the optical component can be made to be in accordance with the following figures and The embodiment is described. The various figures are not to scale to illustrate various embodiments of the invention. The same- or functional parts are denoted by the same reference symbols. [Embodiment] Fig. 1 shows a portion of a thin film light-emitting diode wafer 100 having a carrier 6 and a multilayer structure. The adhesion promoting layer 5 is between the carrier 6 and the multilayer structure 10 . The multilayer structure 10 comprises a light generating region 3 disposed between the p-conductive first semiconductor layer 1 and the n-conductive second semiconductor layer 2. The first semiconductor layer 1 is disposed between the mirror layers 4 of the active region 3 properties. The electrically conductive mirror layer 4 serves as a mirror surface and is an electrical contact layer to the first semiconductor layer. The mirror layer 4 is protected by a diffusion layer 45 which is disposed between the mirror layer 4 and the adhesion promoting layer. The first and second semiconductor layers 1 and 2 and the active region 3 together form the conductor body 123. The semiconductor body 123 together with the diffusion barrier layer 45 surface layer 4 forms a multilayer structure 10. In the above method of manufacturing a thin film light-emitting diode wafer, the second semiconductor layer 2, the region 3 and the first semiconductor layer 1 are sequentially formed in an epitaxial manner on the growth substrate shown here. The mirror layer 4 is applied to the epitaxial layer structure, for example, by evaporation or evaporation. The multilayer structure 1 is joined to the carrier 6 by adhesion promoting 5, which is composed, for example, of tantalum or has a height greater than I. According to the same configuration, the live gold and gold are also used as the barrier 5 and the mirror is not active splashed into the layer mainly -12- 1254469. The growth substrate is then removed. The second semiconductor layer 2 facing the growth substrate forms an emissive layer after the substrate is removed and the surface of the emissive layer remote from the active region 3 forms an emitting surface 20 which is flat in this embodiment. The direction of diffusion of the radiation generated in the active region 3 and the radiation reflected by the mirror layer 4 is indicated by arrows 7 or 8 in Fig. 1. Light generated by the interference of the two kinds of radiation components 7 and 8 is emitted by the multilayer structure 10 in a direction away from the carrier 6. The distance between the mirror layer 4 and the active region 3, which in this form is equal to the thickness of the first semiconductor layer 1, has to be adjusted so that the radiation emitted by the active region 3 can be disturbed by the radiation reflected by the mirror layer 4. Moreover, the lifetime of the combined action for emission in the active zone 3 is affected by such interference. The near-field effect used in the above-described thin film light-emitting diode wafer can be compared with a cavity effect, which is a wave effect generated in an optical resonator (resonant cavity). By this effect, the emission characteristics of the semiconductor for light generation can be adjusted so that most of the photons can be incident on an angle of the exiting interface which is smaller than the angle of total reflection. Therefore, the largest possible portion of the radiation is emitted from the wafer when it is first incident on the exiting interface (= emitting surface 20). Only a small fraction is reflected back into the semiconductors 1, 2, 3. This small portion of the light will cause loss when reflected on the mirror layer 4 and will also be caused by reabsorption in the active region 3 (its quantum efficiency is only about 50%) before it is incident on the interface for injection. loss. Therefore, by using the above-described cavity effect in the thin film light-emitting diode wafer, the recycling rate can be greatly reduced from -13 to 1254469. > Another advantage of using the above-described cavity effect in the thin film light-emitting diode is that <the emission characteristics in the outside of the semiconductor are affected. According to the relationship between the angular distribution of photons in the interior of the semiconductor and the distance between the mirror surface and the layer for generating light, the emission characteristics of the semiconductor can be changed in an unroughened emission surface and, in particular, a preferential direction can be achieved. Radiation distribution. Preferably, the distance d from the layer for the light generation to the mirror layer is for the wavelength λ 〇 = 4 5 5 nm (corresponding to the wavelength of the semiconductor body in the refractive index n = 2.5 λ = 182 nm) In terms of. For the zeroth order radiation emitted, d = 40 nm. For the first order radiation emitted, d = 130 nm. For the second order radiation emitted, d = 230 nm. Each of the above 値 corresponds to (1 = 0.22λ at the zeroth order, d = 0.7 1X at the first order, and ο!=1.26λ at the second order. For other wavelengths, d must be adjusted accordingly. The smaller the order of emission, the higher the efficiency of the thin-film LED. For example, when the second-order emission is converted to the first-order emission, the efficiency is increased by 25%. In a preferred embodiment, the zeroth order emission must be adjusted. A suitable specific configuration of the GaN-based thin film light-emitting diode chip has the following layer sequence: - front side - contact metal layer - highly doped GaN: Si (layer thickness 700-1 500 nm) - lower doped GaN: Si (layer thickness 4000 nm) - undoped GaN (layer thickness 30 nm) - InGaN-quantum well (layer thickness: about 1 nm In content of approximately 10%) -14-1254469 - barrier layer (approximately 5 nm undoped GaN + 6-7 nm lanthanum-doped GaN + approximately 5 nm undoped G a N ) -InGaN-quantum well As above - barrier layer as above - InGaN - quantum well as above - barrier layer as above - InGaN - quantum well (layer thickness: about 2-3 nm; In content is about 20%) - undoped GaN (layer thickness 5-10 Nm - p-doped AlGaN-layer (layer thickness 20-40 nm; electron-barrier layer; aluminum content 10-25%) - P-doped GaN: Mg (terminal layer) - mirror (Pt-layer) Unclosed + Ag-layer + diffusion barrier + case other layer + connection layer if necessary) - 锗 - carrier In the second embodiment of Fig. 2, it differs from the embodiment of Fig. 1 in that Preferably, at least another thin charge carrier-barrier layer 11 is disposed between the active region 3 and the semiconductor layer facing the mirror layer 4 (ie, the first semiconductor layer 1). The charge carrier-barrier layer 11 is preferably a semiconductor. a component of the body and thus grown in an epitaxial manner and having a semiconductivity. Further, in the embodiment of Fig. 2, a passivation layer 8 is provided on the second semiconductor layer 2 by a certain size The thickness is adjusted to a suitable form to form an anti-reflective layer that can be applied, for example, by a deposition process after the growth substrate is removed. The de-reflective layer 8 is not produced in an epitaxial manner and is, for example, made from oxidized sand or nitrogen. -15- 1254469 The embodiment of the thin film light-emitting diode chip of FIG. 3 has a rough _ The emitting surface 20 is different from the embodiment of Fig. 2. The gain achieved by using the cavity ^ effect is therefore only negligibly weakened. The emission characteristics are only insignificantly affected by the variation of the distance from the active region to the mirror surface. Advantageously, an optical component is shown in Fig. 4, which comprises a light emitting diode wafer 100 having a housing, for example, in accordance with the embodiment shown in Figs. The light emitting diode chip 100 is mounted on the lead frame 92 and constructed in the recess of the ^ housing 91. The recess of the outer casing 91 preferably has a surface for light reflection. The light-emitting diode wafer is encapsulated with a potting substance 90. The invention is of course not limited to the scope of the description made in accordance with the various embodiments. Conversely, the invention encompasses each novel feature and each combination of features, and in particular, each of the various features of the invention The combination itself is not explicitly shown in the scope of each patent application or in the respective embodiments. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an example of a thin film light-emitting diode wafer having a flat emitting surface. Figure 2 has a thin film-emitting diode chip of a semiconductor body (which includes a barrier layer) and an anti-reflective layer. Figure 3 shows a thin film light emitting diode wafer having an emitter surface that has been constructed. Figure 4 has an optical assembly of a light emitting diode chip. [Component Symbol Description] 100 LED Diode Wafer 10 Multilayer Construction -16- 1254469
1 第 -. 半 導 體 11 阻 障 層 123 半 導 體 本 體 2 第 二 半 導 體 20 發 射 面 3 活 性 區 4 鏡 面 層 45 擴 散 阻 障 層 5 黏 合促 進 層 6 載 體 7 活 性 1E 3 中 8 由 鏡 面 4 所 90 澆 注 物 質 9 1 外 殻 92 導 線 架 d 鏡 面 層 4 和 層 層 產生的輻射 反射的輻射 活性區3之間的距離1 - semiconductor 11 barrier layer 123 semiconductor body 2 second semiconductor 20 emitting surface 3 active region 4 mirror layer 45 diffusion barrier layer 5 adhesion promoting layer 6 carrier 7 active 1E 3 medium 8 by mirror 4 90 casting material 9 1 housing 92 lead frame d mirror layer 4 and the distance between the layers of the radiation generated by the radiation-reflected active area 3
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