200536162 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.2221中已知一種以GaN爲主之FCLED-晶片（以覆晶 (flip-chip)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 200536162 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，其使磊晶層序列中所 生的電磁輻射之至少一部份反射回到磊晶層序列中； -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 0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 晶之磊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 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 mm 體 生 之 同 於 述 地 200536162 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。 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嘉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 200536162 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鑛而塗佈該鏡面層。 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PbS 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。 200536162 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（β卩，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, 5λΜ)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 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（2ιη+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 200536162 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 ertic)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0·78λ，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，該幅射分佈具有三種 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，可見光區或紫夕^ 光區中。半導體本體可依據波長而以不同的半導體材料# -10- 200536162 統爲基準以製成。例如，一種以IiuGayAlnyAs爲主的半 導體本體適用於長波長的輻射，以inxGayAli_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 InxGayAh-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，其中〇$ 1且 〇 $ y S 1。發出的輻射之光譜寬度例如可爲1 5至4〇 ηηι。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 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 (Lambertic)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 (Lambertic)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- 200536162 凹口中，其中該凹口可具有一種反射用的表面。發光二極 體晶片在該凹口中可以一種澆注物質來包封。藉由使用高 折射率的樹脂（例如，環氧樹脂或矽樹脂，其折射率n大於 1.55)來包封該薄膜晶片，則可使光學組件的發射效率提高。 本發明以下將依據圖式和實施例來描述。各圖式未依據 比例大小來顯示本發明的不同之實施例。相同-或作用相同 的零件以相同的參考符號來表示。 【實施方式】 第1圖顯示薄膜發光二極體晶片100之一部份，其具有 載體6和一種多層構造1〇。載體6和多層構造1〇之間配置 一種黏合促進層5。該多層構造10包含一種光產生用的活 性區3，其配置在p-導電之第一半導體層1和n_導電之第 二半導體層2之間。第一半導體層1配置在活性區3和金 屬性的鏡面層4之間。導電的鏡面層4作爲鏡面用且亦作 爲至.第一半導體層之電性接觸層。鏡面層4受到擴散阻障 層45所保護，該層45配置在鏡面層4和黏合促進層5之 間。第一和第二半導體層1和2以及活性區3 —起形成半 導體本體123。半導體本體123 —起與擴散阻障層45和鏡 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，在此處未顯 示的生長基板上依序以磊晶方式產生第二半導體層2，活性 區3和第一半導體層1。在該磊晶-層構造上例如藉由濺鍍 或蒸鍍而施加該鏡面層4。該多層構造10藉由黏合促進層 5而與載體6相連接，載體6例如由鍺所構成或以鍺爲主要 -12- 200536162 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- 200536162 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 = 45 5 nm (對應於折射率η = 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 = 4 0 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（1 = 0.7 1λ，且在第二階時對應於（1=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lnm; In含量大約10%) -14- 200536162 -阻障層（大約5nm未摻雜的GaN + 6-7 nm矽摻雜的GaN + 大約5 nm未摻雜的GaN) - 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%) - ρ -摻雜的G a N : M g (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 且例如由氧化矽或氮化矽所構成。 -15- 200536162 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90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 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- 200536162 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 3 中 8 由 鏡 面 4 所 90 繞 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 -17-200536162 IX. Description of the invention: [Technical field to which the invention belongs] The present invention relates to a light emitting diode wafer, particularly a thin film light emitting diode wafer. [Prior Art] 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. In 2221, a GaN-based FCLED-wafer (light-emitting diode wafer configured by flip-chip) is known. The sapphire-substrate is used as an emitting layer. Document US 2003 / 0 143772 A1 is known as a thin-film light-emitting diode wafer having an AlGalnN epitaxial structure without a growth substrate. SUMMARY OF THE INVENTION The object of the present invention is to provide a thin-film light-emitting diode wafer with 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 must be adjusted so that a radiation emitted by the active area can be disturbed by the light reflected by the mirror layer With this kind of interference, the quantum efficiency inside the active region will be affected and the active region will achieve a direction-dependent emission characteristic. This direction-dependent emission characteristic has At least one preferred direction. The thin-film light-emitting diode wafer has an emitting layer, which is at least semi-conductive. The emitting layer is therefore not a type of de-reflection 200536162 The characteristics of the thin-film light-emitting diode wafer are particularly Points:-A reflective layer is applied or formed on one of the main surfaces of the epitaxial layer sequence facing the carrier element for radiation generation, which reflects at least part of the electromagnetic radiation generated in the epitaxial layer sequence back to the epitaxial layer. In the crystal layer sequence;-the thickness of the epitaxial layer sequence is in the range of 20 microns or less, especially between 4 microns and 10 microns,-the epitaxial layer sequence includes at least one semiconductor layer, at least one of which The (plane) has a hybrid structure that ideally makes the light in the crystal epitaxial layer sequence form an approximately random cloth, that is, the light has a stray characteristic that is as random as possible. Thin-film light-emitting diode wafers are, in a better approximation, a Lambertic surface emitter. The basic principles of thin-film light-emitting diode wafers have been described, for example, in I. Schnitzer et al. In Appl. Phys. Lett. (16), 18 October 1993, 2174-2176. The so-called thin-film light-emitting diode wafer currently refers specifically to a light-emitting diode wafer having a layer structure with epitaxially grown layers. The growth substrate is preferably removed from the layer structure after a long process. At least a part of the layer grown by epitaxial is a semiconductor layer. The wafer may have a carrier different from the growth substrate, and the layer structure is applied on the carrier. The thin-film light-emitting diode wafer described above does not have a resonator. Compared with RCLED (Resonant Cavity Light Emitting Diode), the above thin-film light-emitting diode chip only contains a single mirror surface. The thin-film light-emitting body wafer, and particularly the epitaxial layer structure, is advantageous over RCLEDs and does not include a Bragg mirror. The third aspect is the same as the above-mentioned ground. It is the same as the above-mentioned ground. 200536162 In a preferred form, the thin-film light-emitting diode chip is dominated by G aN. Compared with GaN-based Flip Chip light-emitting diodes on sapphire substrates, the light generated in the semiconductor body is directly (that is, no absorption loss and reflection loss) due to a The substrate after the epitaxial layer sequence is emitted from the semiconductor body. The optical near-field effect in a thin-film light-emitting diode wafer greatly affects the emission efficiency. The advantage of using the optical near-field effect is that the radiation component emitted by the light-generating semiconductor can be increased. The thin-film wafer mentioned here is characterized by a high emission efficiency, which can exceed 70%. The active region usually has multiple 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 form, and an active region disposed between the two semiconductor layers. The first semiconductor layer is preferably a p-dopant, and the second semiconductor layer is preferably a dopant. The semiconductor layer is preferably transparent, that is, it is transparent to radiation generated in the active region. The semiconductor body may comprise, for example, 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, that is, the charge carrier cannot be moved by the first semiconductor layer in the direction of the mirror layer. come out. The charge carrier-barrier layer is preferably one in which at least a portion is semiconductive and may include aluminum in another form. 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 grown with the crystallite. Each layer of the semiconductor body is grown on a growth substrate, which exists as a wafer 200536162. First, the η-doped second semiconductor layer is preferably deposited in an epitaxial manner. Then, an active region or a partial layer of the active region, a p-doped first semiconductor layer and, if necessary, a charge carrier-barrier layer are sequentially grown in an epitaxial manner. The mirror layer is subsequently coated, preferably by sputtering or evaporation. The mirror layer is preferably a metal layer. The specular layer is preferably a wide band and has high reflectivity, wherein the specular layer can reflect at least 70% (preferably at least 80%) of the incident light, for example. The mirror layer is produced, for example, from Ag, Au, Pt or Al and / or from an alloy of at least two of these metals. The specular layer may also be a multi-layered sequence having a plurality of layers formed of various metals or alloys as described above. The layer composite contains an epitaxial layer sequence, a growth substrate, and a mirror layer. The layer composite is preferably fixedly connected 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 characteristics. demand. The support is preferably one which is conductive or at least semi-conductive. For example, germanium, GaAs, SiC, A1N or silicon 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 connected to the carrier. At least one adhesion promoting layer may be provided between the mirror layer and the carrier. Preferably, the conductive adhesion promoting layer connects the carrier to the epitaxial-layer sequence, wherein the mirror layer faces the carrier. The adhesion-promoting layer may be, in particular, a metal layer composed of PbSη (flux), AuGe, AuBe, AuSi, Sn, In, or Pdln. The mirror layer may be protected by a diffusion barrier layer (for example containing titanium and / or tungsten) facing the adhesion promoting layer. A diffusion barrier layer prevents the material from penetrating into the mirror layer from the adhesion promoting layer. 200536162 All the layers of the light-emitting diode wafer described herein, especially the semiconductor layer of the active region and the semiconductor body, can be composed of multiple partial layers, respectively. The semiconductor body includes an emission layer having an emission surface. The radiation distribution in the emission layer has multiple preferential directions. The emissive layer is preferably the same as the second semiconductor layer (which is, for example, an n-dopant). The first semiconductor layer (which is, for example, a p-dopant) is preferably disposed between the mirror layer and the active region. The mirror layer must be placed close to the light source (β 卩, active area) so that the optical near-field effect is significant when interference occurs. By the interference between the generated light source and the reflected light source, the spontaneous emission in the active region will be affected, especially the lifetime of the combined effect for emission will be affected and therefore the interior of the layer for light generation Quantum efficiency is affected. Specific specular distances to the active region (for example, λ / 4, 3λ / 4, 5λM) produce an advantageous (angle-dependent) emission characteristic. This specific specular distance appears as the internal quantum efficiency increases. The distance between the mirror and the light source is, for example, a maximum of 2λ, where λ = λ0 / η is the wavelength of light in an optical medium (here, the semiconductor body) and λ0 is the wavelength of light in a vacuum. The distance between the light-generating layer and the mirror layer is less than 1.75λ in this embodiment. In another advantageous form, this distance is less than 1.5λ. The advantage of a smaller distance is that the spontaneous emission of the active area can be controlled by the interaction between the radiation generated in the active area and the radiation reflected in the specular layer. The radiation generated by the light source and the radiation reflected by the mirror can form a 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 (2ιη + 1) λ / 4η, where η is the refractive index of the optical medium and m = 0,1,2, ... is the order of emission, then it is vertical The largest distribution of radiation occurs in the incident radiation at the interface of the 200536162 optical medium. At the zeroth order emission, all photons are emitted in a cone whose axis of rotation symmetry is perpendicular to the emission interface. In the first-order emission, there is another emission characteristic, which has a large angle to the perpendicular of the emission surface. There are m such additional emission characteristics at the m-th transmission. By adjusting the distance between the light-generating layer and the specular layer (which is (2ιη + 1) λ / 4), the active region can achieve an aligned emission characteristic, which is consistent with Lambertic (Lambertic ) Areas with different emission characteristics and a high-intensity and low-intensity interactive configuration. The distance from the mirror to the layer for light generation must be selected and therefore the emission characteristics in the interior of the semiconductor must also be adjusted so that a high radiation component already exists in the more total reflection when it is first incident on the interface for light exit The critical angle is still in a small range. The distance between the mirror layer and the active area can be, for example, in various embodiments: 1) 0 · 16λ. To 0 · 28λ, that is, approximately λ / 4; the radiation distribution has a preferential direction, which is perpendicular to the emission surface 2) 0 · 63λ to 0 · 78λ, that is, about 3λ / 4; the radiation distribution has two preferential directions, namely, a direction perpendicular to the emission surface and a direction inclined thereto; 3) 1 · 15λ to 1 · 38λ ', that is, about 5λ / 4, the radiation distribution has three preferential directions, namely, a direction perpendicular to the emission surface and two directions inclined to it. The wavelength of the emitted radiation can be located in the infrared, visible, or purple light region. The semiconductor body can be made based on different semiconductor materials # -10- 200536162 according to the wavelength. For example, a semiconductor body based on IiuGayAlnyAs is suitable for long wavelength radiation, a semiconductor body based on inxGayAli_x yP is suitable for visible red to yellow radiation, and a semiconductor body based on InxGayAh-x-yN is suitable for short wavelengths. Visible (green to blue) radiation or ultraviolet (UV) radiation, of which 0 $ 1 and 0 $ yS1. 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 light generating layer and the specular layer is preferably the same as the thickness of the p_ layer. In another embodiment, the second semiconductor layer may have a flat emission surface. The emission characteristics of the light emitted by the wafer are different from the Lambertic emission characteristics in this case and in at least one preferential direction It has a higher radiation density and a smaller radiation density in other angular ranges. In another embodiment, the emission surface of the second semiconductor layer must be formed so that the radiation that is not emitted when incident on the interface can be scattered back into the semiconductor in different directions. By redistributing the radiation direction, a so-called waveguide effect is prevented, and thus the emission efficiency is improved. The emission characteristics of the radiation emitted by the wafer in this case basically have Lambertic emission characteristics. The second semiconductor layer may be disposed between the active region and the anti-reflection layer, and the thickness of the anti-reflection layer is approximately equal to a quarter of the wavelength. The dereflective layer is preferably a dielectric layer, which is applied to the emitting surface of the semiconductor body after the growth substrate is removed. The light-emitting diode wafer is preferably arranged in a recess of a housing in the photovoltaic module, wherein the recess may have a reflective surface. The light emitting diode wafer can be encapsulated in the recess with a potting substance. By using a high refractive index resin (for example, epoxy resin or silicone resin, whose refractive index n is greater than 1.55) to encapsulate the thin film wafer, the emission efficiency of the optical component can be improved. The present invention will be described below with reference to the drawings and embodiments. The drawings do not show different embodiments of the invention according to the scale. Identical-or identically acting parts are identified by the same reference symbols. [Embodiment] Fig. 1 shows a part of a thin film light emitting diode wafer 100 having a carrier 6 and a multilayer structure 10. An adhesion promoting layer 5 is disposed between the carrier 6 and the multilayer structure 10. The multilayer structure 10 includes an active region 3 for light generation, which is disposed between a p-conductive first semiconductor layer 1 and an n-conductive second semiconductor layer 2. The first semiconductor layer 1 is arranged between the active region 3 and the mirror layer 4 having a gold property. The conductive mirror layer 4 serves as a mirror and also serves as an electrical contact layer to the first semiconductor layer. The mirror layer 4 is protected by a diffusion barrier layer 45, which is disposed between the mirror layer 4 and the adhesion promoting layer 5. The first and second semiconductor layers 1 and 2 and the active region 3 together form a semiconductor body 123. The semiconductor body 123 forms a multilayer structure 10 with the diffusion barrier layer 45 and the mirror layer 4. In the above-mentioned method for manufacturing a thin-film light-emitting diode wafer, a second semiconductor layer 2, an active region 3, and a first semiconductor layer 1 are sequentially formed in an epitaxial manner on a growth substrate not shown here. The mirror layer 4 is applied to the epitaxial layer structure, for example, by sputtering or evaporation. The multilayer structure 10 is connected to a carrier 6 through an adhesion promoting layer 5. The carrier 6 is made of, for example, germanium or contains germanium as a main component. The growth substrate is then removed. The second semiconductor layer 2 facing the growth substrate forms an emission layer after the substrate is removed and the surface of the emission layer far from the active region 3 forms an emission surface 20, which is flat in this embodiment. The directions of diffusion of the radiation generated in the active region 3 and the radiation reflected by the mirror layer 4 are indicated by arrows 7 or 8 in the first figure. The light generated by the interference of the two radiation components 7 and 8 is emitted from 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) must be adjusted so that the radiation emitted by the active region 3 can be disturbed by the radiation reflected by the mirror layer 4. And the lifetime of the combined action for emission in the active region 3 will be affected by such interference. The near-field effect used in the above thin-film light-emitting diode wafer can be compared with a cavity effect. The so-called cavity refers to a wave effect generated in an optical resonator (. Resonant cavity). With this effect, the emission characteristics of the light-generating semiconductor can be adjusted so that most of the photons can be incident on an angle on the exit interface, which is smaller than the angle of total reflection. Therefore, the largest possible part of the radiation is emitted from the wafer when it is first incident on the emission interface (= emission surface 20). Only a small portion is reflected back into semiconductors 1, 2, and 3. This small part of the light will cause loss when it is 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 exit interface again. loss. Therefore, by using the above-mentioned cavity effect in a thin-film light-emitting diode wafer, the recycling rate (Recycling rate) can be greatly reduced -13- 200536162. Another advantage of the thin-film light-emitting diode by using the above-mentioned cavity effect 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 semiconductor relative to the distance between the mirror surface and the layer for light generation, the emission characteristics outside the semiconductor can be changed in an unroughened emission surface, and in particular, a preferential direction can be achieved Radiation distribution. The better distance d between the light-generating layer and the mirror layer is for radiation having a wavelength λ0 = 45 5 nm (corresponding to a wavelength λ = 182 nm in a semiconductor body with a refractive index η = 2.5). For the zeroth-order radiation emitted, d = 40 nm. For the emitted first-order radiation, d = 130 nm. For the emitted second-order radiation, d = 230 nm. Each chirp described above corresponds to (1 = 0.22λ at the zeroth order, (1 = 0.7 1λ at the first order, and (1 = 1.26λ at the second order). For other wavelengths, , D must be adjusted accordingly. The smaller the number of emission steps, the higher the efficiency of the thin-film light-emitting diode wafer. For example, when switching from the second-order emission to the first-order emission, the efficiency increases by 25% In a preferred embodiment, therefore, the zeroth-order emission must be adjusted. A suitable specific configuration of a GaN-based thin-film light-emitting diode wafer 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: approximately lnm; In content is about 10%) -14- 200536162-Barrier layer (about 5nm undoped GaN + 6-7 nm silicon-doped GaN + about 5 nm undoped GaN)-InGaN-quantum well as above-resistance Barrier layer as above-InGaN-quantum well as above-Barrier layer as above-InGaN-quantum well (layer thickness: about 2-3 nm; In content 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%)-ρ-doped G a N: M g (terminal layer)-mirror surface (Pt-layer is not closed + Ag-layer + diffusion barrier + other layers + connection layer if necessary) -Ge-Carrier In the second embodiment of FIG. 2, it is different from the embodiment of FIG. 1 It is here that at least another thin charge carrier-barrier layer 11 is preferably arranged between the active region 3 and the semiconductor layer (ie, the first semiconductor layer 1) facing the mirror layer 4. The charge carrier-barrier layer 11 Preferably, it is a component of the semiconductor body and is thus grown in an epitaxial manner and has semiconductivity. In addition, in the embodiment of FIG. 2, a passivation layer 8 is provided on the second semiconductor layer 2. An anti-reflection layer is formed by adjusting the thickness of a certain size to an appropriate form, which can be applied after the growth substrate is removed, for example, by a deposition process. The anti-reflection layer 8 is not produced in an epitaxial manner and is formed, for example, by It is made of silicon oxide or silicon nitride. -15- 200536162 The embodiment of the thin-film light-emitting diode chip shown in FIG. The emitting surface 20 is different from the embodiment in FIG. 2. The gain achieved by using the cavity effect is therefore only slightly reduced. The emission characteristics are only slightly affected by the change in the distance from the active area to the mirror surface. It is advantageous. FIG. 4 shows an optical element comprising, for example, a light-emitting diode wafer 100 with a housing according to the embodiments shown in FIGS. 1 to 3. The light emitting diode wafer 100 is mounted on a lead frame 92 and is constructed in a recess of the case 91. The recess of the case 91 preferably has a surface for reflecting light. The light-emitting diode wafer is encapsulated with a casting substance 90. The invention is of course not limited to the scope of the description based on the embodiments. On the contrary, the present invention includes each new feature and each combination of features, which in particular includes each combination of different patent application scopes or different features of different embodiments, when the related features or related The same applies when the combination itself is not clearly shown in the scope of each patent application or each embodiment. [Brief description of the drawing] Fig. 1 is an example of a thin-film light emitting diode wafer having a flat emitting surface. FIG. 2 is a thin film light emitting diode wafer having a semiconductor body (which includes a barrier layer) and a dereflective layer. Fig. 3 is a thin-film light-emitting diode wafer having a structured emission surface. Fig. 4 is an optical module having a light emitting diode wafer. [Description of element symbols] 100 Light-emitting diode wafer 10 Multi-layer structure -16- 200536162 1 First --- Semiconductor 11 Barrier layer 123 Semiconductor body 2 Second semiconductor 20 Emission surface 3 Active area 4 Mirror layer 45 Diffusion barrier layer 5 Adhesion Promoting layer 6 Carrier 7 Active 3 Medium 8 Injected substance 9 by mirror 4 9 Shell 92 Lead frame d The distance between the radiation active region 3 of the mirror layer 4 and the radiation reflection generated by the layer -17-