1275190 九、發明說明： 【發明所屬之技術領域】 本發明係關於半導體發光元件用正極，尤其係關於適合 於氮化鎵系化合物半導體發光元件之可以低驅動電壓獲得 強發光之半導體發光元件用透光性正極。 【先前技術】 近年來用以發出短波長光的發光元件用半導體材料，有 一種GaN (氮化鎵）系化合物半導體材料受到世人的注目 ® 。GaN系化合物半導體係以藍寶石單結晶以及各種氧化物 或ιπ-ν族化合物作爲基板，而在其上以金屬有機化學氣 相生長法（MOCVD法）或分子束磊晶生長法（MBE法） 等所形成。[Technical Field] The present invention relates to a positive electrode for a semiconductor light-emitting device, and more particularly to a semiconductor light-emitting device which is suitable for a gallium nitride-based compound semiconductor light-emitting device and which can obtain strong light emission with a low driving voltage. Light positive electrode. [Prior Art] In recent years, a semiconductor material for a light-emitting element for emitting short-wavelength light has a GaN (gallium nitride)-based compound semiconductor material which has attracted attention from the world. The GaN-based compound semiconductor has a single crystal of sapphire and various oxides or an iππ-ν compound as a substrate, and is subjected to metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). Formed.
GaN系化合物半導體材料之特性係具有朝著橫方向的電 流擴散小之情形。其原因似爲在磊晶中存在許多由基板朝 著表面穿通的錯位，但是詳情並未清楚。加上在p型之 GaN系化合物半導體，其電阻率是高於n型之GaN系化合 ^ 物半導體的電阻率，結果導致若僅在其表面積層金屬時， 則其結果是幾乎並無p型半導體層內之橫的電流擴散，因 此若作成爲具有pn接合之LED結構時，則僅能在正極之 正下面發光。 因此，大都使用可將在正極正下面所產生之發光穿過正 極而取出於外部之透光性正極。特別是一般慣用之技術中 有一種提案揭示作爲正極而在p型半導體層上使Ni與Au 分別積層約數1 〇奈米（nm )並在氧氣氣氛下施加合金化 1275190 處理，以促進P型半導體層之低電阻化及形成具有透光性 與歐姆性的正極之方法（參閱發明專利第2,8 03，742號公報 )° 透光性電極所需之材料，係包括導電性金屬氧化物或所 形成極薄之金屬等。該等材料及結構由於如欲直接接合則 有困難，因此一般採取使具有某一程度厚度之接合用焊墊 電極，以電氣方式連接於透光性電極之方法來配置。然而 ，由於該焊墊電極係一種具有某一程度厚度之金屬材料， • 不具透光性，以致有在焊墊電極正下方所產生之發光則不 能取出於外部之缺點存在。 此外，爲提高焊墊電極之密著性，已有一種提案揭示在 透光性電極之一部份形成切口，並形成跨設於該部份及鄰 接的透光性電極上之焊墊電極，以直接接於GaN半導體層 之部份來獲得接合強度同時以接於透光性電極上之部份來 使電流擴散之結構。（參閱日本發明專利特開平第7-94782 號公報） ^ 此外，由於不能使焊墊電極正下方所產生之發光取出於 外部，因此爲有效率地利用電流，迄今爲止則朝向對焊墊 電極正下方不注入電流以使光不會在焊墊電極正下方產生 之方向的技術探討。 例如已公開一種如在焊墊電極下方設置絶緣區域，使電 流不注入於焊墊下即可有效率地獲得發光之技術（參閱日 本發明專利特開平第8-250768號公報及特開平第8-250769 號公報）。此外，也已公開一種藉由以接觸電阻率相對於 1275190 v P型層爲高的金屬來形成焊墊電極之最下面，以使電流不 會注入於該區域之技術（參閱日本發明專利特開平第10-2425 1 6號公報）。 然而，根據吾人之檢討，若使用該等方法時，則由於將 導致正極對於p型層作歐姆接觸的面積減少，因此將造成 驅動電壓上升之缺點。 【發明內容】 爲解決上述問題，本發明之目的係提供一種以低驅動電 ^ 壓即可獲得強發光之面朝上組裝型晶片用之透光性正極。 在本發明所謂「透光性」係意謂對發光波長區域之光爲透 光性。在氮化鎵系化合物半導體發光元件之情形時，通常 發光波長區域係在3 00〜600奈米範圍。 本發明提供如下列之發明。 (1) 一種半導體發光元件用正極，其特徵爲由形成在 半導體層上之透光性電極及形成在該透光性電極 上之接合墊電極所構成，該接合墊電極係至少在 ^ 與透光性電極相接之面設置反射層。 (2) 如上述第1項之半導體發光元件用正極，其中反 射層與透光性電極之密著強度係以剝離強度計則 爲490 mN ( 50克力）以上。 (3) 如上述第1或2項之半導體發光元件用正極，其 中透光性電極在元件所發光之發光波長的光之透 射率爲60%以上。 (4) 如上述第1至3項中之任一項之半導體發光元件 -7- 1275190 (6)The characteristics of the GaN-based compound semiconductor material are such that the current diffusion in the lateral direction is small. The reason for this seems to be that there are many misalignments in the epitaxial crystal that pass through the substrate toward the surface, but the details are not clear. In addition, in the p-type GaN-based compound semiconductor, the resistivity is higher than that of the n-type GaN-based compound semiconductor, and as a result, if the metal is only on the surface layer, the result is almost no p-type. Since the lateral current in the semiconductor layer is diffused, if it is an LED structure having a pn junction, it can emit light only under the positive electrode. Therefore, a light-transmitting positive electrode which can take out the light emitted directly under the positive electrode through the positive electrode and take it out to the outside is used. In particular, there is a proposal in the conventional technique to disclose that Ni and Au are laminated on the p-type semiconductor layer by about 1 nanometer (nm) as a positive electrode, and alloying 1275190 is applied under an oxygen atmosphere to promote the P-type semiconductor. A method of reducing the resistance of the layer and forming a positive electrode having light transmissivity and ohmicity (refer to Japanese Laid-Open Patent Publication No. 2,8 03,742). The material required for the translucent electrode includes a conductive metal oxide or A very thin metal or the like is formed. Since these materials and structures are difficult to be joined directly, they are generally disposed by a method in which a bonding pad electrode having a certain thickness is electrically connected to the translucent electrode. However, since the pad electrode is a metal material having a certain thickness, it is not translucent, so that there is a disadvantage that the light emitted directly under the pad electrode cannot be taken out. In addition, in order to improve the adhesion of the pad electrode, there has been a proposal to form a slit in one portion of the translucent electrode and to form a pad electrode spanning the portion and the adjacent translucent electrode. A structure in which a bonding strength is directly connected to a portion of the GaN semiconductor layer and a current is diffused by a portion connected to the transparent electrode. (Japanese Unexamined Patent Publication No. Hei 7-94782) In addition, since the light emitted directly under the pad electrode cannot be taken out to the outside, the current is efficiently used, and the electrode is facing the pad electrode so far. A technical discussion in which no current is injected below to cause light to be generated in the direction directly under the pad electrode. For example, there has been disclosed a technique in which an insulating region is provided under the electrode of the pad so that current can be efficiently obtained without injecting a current into the pad (refer to Japanese Laid-Open Patent Publication No. 8-250768 and No. 8-32 Bulletin No. 250769). Further, a technique of forming the bottom of the pad electrode by a metal having a contact resistivity higher than that of the 1275190 v P-type layer has been disclosed so that current is not injected into the region (see Japanese Patent Laid-Open No. Bulletin 10-2425 1 6). However, according to our review, if these methods are used, the area where the positive electrode is ohmically contacted with the p-type layer is reduced, which causes a disadvantage that the driving voltage rises. SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a light-transmitting positive electrode for a face-up assembly type wafer which can obtain strong light emission with low driving voltage. The term "transparency" as used in the present invention means that the light in the light-emitting wavelength region is light-transmitting. In the case of a gallium nitride-based compound semiconductor light-emitting device, the light-emitting wavelength region is usually in the range of 300 to 600 nm. The present invention provides the following invention. (1) A positive electrode for a semiconductor light-emitting device, comprising: a translucent electrode formed on a semiconductor layer; and a bonding pad electrode formed on the translucent electrode, the bonding pad electrode being at least A reflective layer is disposed on the surface where the photoelectrode is in contact with each other. (2) The positive electrode for a semiconductor light-emitting device according to the above item 1, wherein the adhesion strength between the reflective layer and the translucent electrode is 490 mN (50 gram force) or more in terms of peel strength. (3) The positive electrode for a semiconductor light-emitting device according to the first or second aspect, wherein the transmissive electrode has a transmittance of light of 60% or more at an emission wavelength of the element. (4) A semiconductor light-emitting element according to any one of items 1 to 3 above - 7 to 1275190 (6)
10 )10)
用正極，其中反射層係由選自由Al、Ag、Pt族金 屬及含有該等金屬中之至少一種之合金所構成之 族群之金屬所構成。 如上述第1至4項中之任一項之半導體發光元件 用正極，其中半導體發光元件爲氮化鎵系化合物 半導體發光元件。 如上述第1至5項中之任一項之半導體發光元件 用正極，其中反射層係由選自由Al、Ag、Pt、及 含有該等金屬中之至少一種之合金所構成之族群 之金屬。 如上述第1至6項中之任一項之半導體發光元件 用正極，其中反射層之厚度爲20〜3，000奈米。 如上述第1至7項中之任一項之半導體發光元件 用正極，其中接合墊電極爲層狀結構，具有反射 層加上由Ti、Cr或A1所構成之阻障層、和/或由 Au或A1所構成之最頂層。 如上述第1至8項中之任一項之半導體發光元件 用正極，其中透光性電極之接合墊電極側爲由金 屬所構成之層。 如上述第1至8項中之任一項之半導體發光元件 用正極，其中透光性電極之接合墊電極側爲由透 明材料所構成之層。 如上述第10項之半導體發光元件用正極，其中透 光性電極係僅由金屬以外之透明材料所構成。 1275190 (12) 如上述第1至11項中之任~項之半導體發光元件 用正極，其中在透光性電極之最表面層施加用以 取出光所需之加工。 (13) 如上述第12項之半導體發光元件用正極，其中透 光性電極之最表面層爲透明材料。 (14) 如上述第1至丨3項中之任一項之半導體發光元件 用正極，其中透光性電極係具有相接於p型半導 體層之接觸層及該接觸層上之電流擴散層。 (15) 如上述第14項之半導體發光元件用正極，其中接 觸層爲白金族金屬或其合金。 (16) 如上述第15項之半導體發光元件用正極，其中接 觸層爲白金。 (17) 如上述第14至16項中之任一項之半導體發光元 件用正極，其中接觸層之厚度爲〇.1〜7.5奈米。 (18) 如上述第17項之半導體發光元件用正極，其中接 觸層之厚度爲0.5〜2.5奈米。 (19) 如上述第14至18項中之任一項之半導體發光元 件用正極，其中電流擴散層爲選自由金、銀及銅 所構成之族群之金屬或至少含有其等之一種之合 金。 (20) 如上述第19項之半導體發光元件用正極，其中電 流擴散層爲金或金合金。 (21) 如上述第14至20項中之任一項之半導體發光元 件用正極，其中電流擴散層之厚度爲1〜20奈米 1275190 (22) 如上述第21項之半導體發光元件用正極，其中電 流擴散層之厚度爲3〜6奈米。 (23) 如上述第14至18項中之任一項之半導體發光元 件用正極，其中電流擴散層爲導電性透明材料。A positive electrode is used, wherein the reflective layer is composed of a metal selected from the group consisting of Al, Ag, Pt metal, and an alloy containing at least one of the metals. The positive electrode for a semiconductor light-emitting device according to any one of the items 1 to 4, wherein the semiconductor light-emitting device is a gallium nitride-based compound semiconductor light-emitting device. The positive electrode for a semiconductor light-emitting device according to any one of the items 1 to 5, wherein the reflective layer is a metal selected from the group consisting of Al, Ag, Pt, and an alloy containing at least one of the metals. The positive electrode for a semiconductor light-emitting device according to any one of the items 1 to 6, wherein the reflective layer has a thickness of 20 to 3,000 nm. The positive electrode for a semiconductor light-emitting device according to any one of the items 1 to 7, wherein the bonding pad electrode has a layered structure, has a reflective layer plus a barrier layer composed of Ti, Cr or A1, and/or The top layer of Au or A1. The positive electrode for a semiconductor light-emitting device according to any one of the items 1 to 8, wherein the bonding pad electrode side of the translucent electrode is a layer composed of a metal. The positive electrode for a semiconductor light-emitting device according to any one of the items 1 to 8, wherein the bonding pad electrode side of the translucent electrode is a layer made of a transparent material. The positive electrode for a semiconductor light-emitting device according to the above item 10, wherein the light-transmitting electrode is made of a transparent material other than metal. The positive electrode for a semiconductor light-emitting device according to any one of the above-mentioned items 1 to 11, wherein a process for extracting light is applied to the outermost layer of the light-transmitting electrode. (13) The positive electrode for a semiconductor light-emitting device according to the above item 12, wherein the outermost layer of the light-transmitting electrode is a transparent material. The positive electrode for a semiconductor light-emitting device according to any one of the items 1 to 3, wherein the translucent electrode has a contact layer that is in contact with the p-type semiconductor layer and a current diffusion layer on the contact layer. (15) The positive electrode for a semiconductor light-emitting device according to Item 14, wherein the contact layer is a platinum group metal or an alloy thereof. (16) The positive electrode for a semiconductor light-emitting device according to item 15, wherein the contact layer is platinum. (17) The positive electrode for a semiconductor light-emitting device according to any one of the items 14 to 16, wherein the contact layer has a thickness of from 0.1 to 7.5 nm. (18) The positive electrode for a semiconductor light-emitting device according to item 17, wherein the contact layer has a thickness of 0.5 to 2.5 nm. (19) The positive electrode for a semiconductor light-emitting device according to any one of the items 14 to 18, wherein the current diffusion layer is a metal selected from the group consisting of gold, silver, and copper, or an alloy containing at least one of them. (20) The positive electrode for a semiconductor light-emitting device according to the above item 19, wherein the current diffusion layer is gold or a gold alloy. (21) The positive electrode for a semiconductor light-emitting device according to any one of the above-mentioned items, wherein the thickness of the current diffusion layer is 1 to 20 nm 1275190. The thickness of the current diffusion layer is 3 to 6 nm. (23) The positive electrode for a semiconductor light-emitting device according to any one of the items 14 to 18, wherein the current diffusion layer is a conductive transparent material.
(24) 如上述第1〇、11、13及23項中之任一項之半導 體發光元件用正極，其中透明材料爲選自由銦錫 氧化物、氧化鋅、氧化鋁鋅、摻氟的氧化錫、氧 化鈦、硫化鋅、氧化鉍及氧化鎂所構成之族群中 之至少一種。 (25) 如上述第24項之半導體發光元件用正極，其中透 明材料爲選自由銦錫氧化物、氧化鋅、氧化鋸鋅 、摻氟的氧化鋅所構成之族群中之至少一種。 (26) 如上述第10、11、13及23至25項中之任一項之 半導體發光元件用正極，其中透明材料之厚度爲 10〜5,000奈米。 (27) 如上述第26項之半導體發光元件用正極，其中透 明材料之厚度爲100〜1，000奈米。 (28) —種半導體發光元件，係使用如上述第1至27項 中之任一項之正極。 (29 ) —種氮化鎵系化合物半導體發光元件，係在基板 上將由氮化鎵系化合物半導體所構成之η型半導 體層、發光層及Ρ型半導體層依此順序設置，並 在Ρ型半導體層及η型半導體層上分別設置正極 -10- 1275190 及負極之發光元件中，正極爲如申請專利範圍第 1至27項中之任一項之正極。 (30) —種燈，係使用如上述第28或29項之發光元件 所構成。 經在用以使電流流通於透光性電極所需之接合墊電極之 至少與透光性電極相接之面設置反射層，即可降低在接合 墊電極與透光性電極相接之面的光之吸收所引起的光之衰 減程度，可有效率地提高所發光的光之取出效率，提高發 # 光強度。 【實施方式】 〔本發明之最佳實施方式〕 第1圖係展示具有本發明之正極的發光元件之一實例剖 面模式圖。1 0爲本發明之正極，係由透光性電極（1 1 )及 接合墊電極（1 3 )所構成。透光性電極（1 1 )係例如由接 觸層（1 1 1 )及電流擴散層（1 1 2 )所構成。接合層電極（ 1 3 )係例如由反射層（1 3 1 )、阻障層（1 3 2 )及最頂層（ ^ 1 3 3 )之3層結構所構成。1爲基板。2爲GaN系化合物半 導體層，其係由η型半導體層3、發光層4及p型半導體 層5所構成。6爲緩衝層、20爲負極。 在具備透光性正極之面朝上組裝型型晶片，其在發光層 (4 )所發光之光中，僅有朝向未存在接合墊電極的透光性 電極部之光及朝向晶片側面之光才能取出於外部。 若使用本發明之正極時，朝向接合墊電極（1 3 )之光， 則將在接合墊電極最下面（與透光性電極相接之面）之反 -11 - 1275190 射層（1 3 1 )受到反射，其一部份將散射而朝向橫方向或斜 方向行進，一部份將朝向接合墊電極之正下方行進。受到 散射而朝向橫方向或斜方向行進之光，將由晶片側面取出 於外部。另一方面朝向接合墊電極之正下方方向所行進之 光，將在晶片下面再受到散射或反射而經由側面或透光性 電極（在上面並無接合墊電極存在的部份）而取出於外部 〇 如此，經在接合墊電極最下面設置反射層，藉此，即可 • 向外部取出經在接合墊電極正下方所產生之發光，以保持 高發光強度。若在接合墊電極最下面有光的吸收時，在焊 墊電極正下方所產生之發光，其大部份將在焊墊電極之最 下面被吸收，以致不能取出於外部。 反射層必須直接密著於透光性電極是爲顯現本發明功效 所需之條件。因此，若接合墊欲獲得充分的強度時，則反 射層必須對於透光性電極受到強固的接著。最低限度在以 一般方法使金線連接在接合墊之步驟中不能允許剝離，爲 • 此，以剝離強度計必須具有約490 mN ( 50克力）之強度 。較佳爲784 mN ( 80克力）以上，且更佳爲980 mN ( 100 克力）以上。 若欲增強反射層與透光性電極之密著強度時，則可採取 設法改善透光性電極的表面之前處理，或在形成反射層之 後施加熱處理等之方法。 反射層之反射率，雖然會因反射層之構成材料而大幅度 地變化，但是較佳爲60%以上，更佳爲80%以上，且特佳 -12- 1275190 爲90%以上。 反射率係可以被稱爲分光光度計之裝置等來比較容易地 加以測定。然而，由於接合墊電極本身是面積小，難於測 定反射率。於是可採取將透明的例如玻璃製之面積較大的 「虛設（dummy )基板」在形成接合墊電極時擺放在反應 室，同時在虛設基板上製造相同的接合墊電極然後加以測 定等之方法來測定。 接合墊電極之反射層，較佳爲以高反射率之金屬來構成 ，更佳爲以Pt、Rh、Ru、Ir等之白金族金屬、A卜Ag、及 含有該等金屬中之至少一種之合金來構成。其中，A卜Ag 、Pt及含有該等金屬中之至少一種之合金，若從其係作爲 電極用之一般性材料，容易取得，且容易使用等之觀點來 看，則較爲優異。 接合墊電極係在透光性電極不加以形成缺口部或窗部而 直接形成在透光性電極上。由於形成在透光性電極上，可 在不致於造成歐姆接觸的面積減少下，或即使爲在接合墊 電極之正下方也不致於造成電極之接觸電阻增加之情況下 ，能防止驅動電壓上升。而且，由於透射過透光性電極之 光將在接合墊電極最下面之反射層受到反射，因此可抑制 光的無益的吸收。 接合墊電極，只要使其位於透光性電極之上面時，則在 任何位置皆可形成。例如也可形成在距自負極爲最遠的位 置，也可形成在晶片之中心等。惟若形成在太靠近於負極 之位置時，則在接合時容易造成線間、球間之短路，因此 -13 - 1275190 不佳。 此外，接合墊電極面積雖然儘可能使其愈大即愈容易進 行接合作業，但是將妨礙發光之取出。例如如爲會覆蓋超 過晶片面之一半面積之面積時，則將妨礙發光之取出，使 輸出顯著降低。相反地，若太小時，則難於執行接合作業 ，使得製品之良率降低。具體而言，較佳爲比接合球直徑 爲約稍微大一些，一般爲約1 〇 〇微米（# m)直徑的圓形 〇 B 接合墊電極之反射層，若以具有高反射率之金屬形成時 ，則較佳爲厚度爲20〜3，000奈米。若反射層爲太薄時， 則不能獲得充分的反射效果。太厚時，則不能產生特別的 優點，僅造成製程時間拖長與浪費材料而已。因此，更佳 爲50〜1，000奈米，且最佳爲100〜500奈米。 接合墊電極也可僅以上述高反射率之金屬來構成。亦即 ，接合墊電極可僅由反射層來構成。然而，接合墊電極已 知經使用各種材料的各種結構者，在該等習知者之半導體 ® 層側（透光性電極側）也可新設置上述反射層，而且也可 將該等習知者之半導體層側最下層取代爲上述反射層。 在如此之積層結構時，對於比反射層位於上方之積層結 構部，並無特殊限定，任何結構皆可使用。例如形成在接 合墊電極之反射層上方的層是具有強化接合墊電極之全體 強度的作用。因此，必須使用比較強固的金屬材料，或是 使膜厚作成爲足夠的厚度。較佳的材料是Ti、Cr或A1。 其中Ti係從材料強度之觀點來看，則較爲理想。經賦予如 -14- 1275190 此之功能時，則將該層稱爲阻障層。 阻障層也可由反射層來兼用。若將具有良好的反射率， 且機械性上是強固的金屬材料形成爲厚時，則不必勉強形 成阻障層。例如以A1作爲反射層來使用時，則不必形成阻 障層。 阻障層之厚度較佳爲20〜3，000奈米。若阻障層爲太薄 時，則不能獲得足夠的強化強度之功效，太厚也不能產生 特別的優點，反而僅造成成本增加而已。更佳的是5 0〜 1，000奈米’最佳的是100〜500奈米。 接合墊電極之最頂層（與反射層成相反之側），較佳爲 採用與接合球之密著性良好的材料。接合球多半是使用金 ，與金球密著性良好的金屬係以Au與A1爲眾所皆知。其 中特別佳的是金。該最頂層之厚度較佳爲50〜1，〇〇〇奈米 ，且更佳爲100〜500奈米。太薄時，與球之接合球密著 性將惡化，太厚時也不會特別產生優點，僅造成成本增加 而已。 對於供形成在半導體層（P型層）上的透光性電極所要 求之較佳性能，係包括與P型層之接觸電阻小，對於由電 極面側取出來自發光層之光的面朝上組裝型之發光元件則 要求具有優具的光透射性，及爲使電流均勻分散於p型層 全面所需之優異的導電性。 透光性電極已知有使用各種材料之各種結構者，在本發 明中也可無任何限制下使用該等習知的透光性電極。然而 ，爲了符合上述要求性能條件，較佳爲與P型層相接的接 -15- 1275190 觸層及位於該接觸層上且用以輔助電流擴散的電流擴散層 之至少2層結構的透光性電極。當然只要能符合上述要求 性能條件時，則也可爲兼作接觸層與電流擴散層之功能的 一層方式，若採取一層結構時，則有並無製程複雜之優點 〇 對接觸金屬層所要求之性能係必須爲與P型之接觸電阻 爲小，從此觀點來考量，接觸層之材料較佳爲白金（Pt ) 、釕（Ru)、餓（Os)、铑（Rh)、銥（Ir)、鈀（Pd) • 等之白金族金屬或該等之合金。該等之中，Pt由於其功函 數高，對於未經施加高溫熱處理之比較高電阻的p型GaN 系化合物半導體層以非加熱下可獲得優良的歐姆接觸，因 ^ 此特別佳。 •若接觸金屬層係以白金族金屬或含有該等之合金來構成 時，則從透光性的觀點來考量，則必須使其厚度形成爲非 常薄。接觸金屬層之厚度較佳爲0.1〜7.5奈米之範圍。若 薄於0.1奈米時，則不易獲得穩定的薄層。若比7.5奈米爲 ® 厚時，則透光性將下降，因此更佳爲5奈米以下。此外， 若考慮到其後續的電流擴散層之積層所引起之透光性下降 與成膜之穩定性時，則特佳爲在0.5〜2..5奈米之範圍。 但是若使接觸金屬層厚度形成爲薄時，則接觸金屬層之 面方向電阻將升高，且與比較高電阻的P型半導體層起相 互作用而導致電流僅能擴散於電流注入部的焊墊層之周邊 部，結果有可能造成不均勻發光模式，使得發光輸出下降 之情況。 -16- 1275190 因此，作爲補充接觸金屬層的電流擴散性之方法，而若 將由高透光率且比接觸金屬層爲高導電性的金屬薄膜所構 成之電流擴散層配置在接觸金屬層上時，藉此當可在不致 於大幅度地損害到白金族金屬的低接觸電阻性或透光率下 可均勻地使電流擴散，結果可獲得高發光輸出之發光元件 〇 電流擴散層之材料較佳爲高導電率之金屬，例如選自由 金、銀及銅所構成之族群中之金屬或含有此等中之至少一 種之合金。其中金是因爲製成爲薄膜時之透光率高，所以 最佳。 另一方面，電流擴散層之材料，也可以高導電率之硫化 鋅及金屬氧化物，例如也可以銦錫氧化物（ITO ) 、ZnO、 氧化鋁鋅、摻氟的氧化錫、氧化鈦、氧化鉍及氧化鎂等之 透明材料來形成。此種透明材料，其光透射率也爲高，因 此爲較佳。其中銦錫氧化物、ZnO、氧化鋁鋅及摻氟的氧 化錫係以導電性高爲眾所皆知，因此爲較佳。 以金屬形成電流擴散層時，其厚度較佳爲1〜20奈米。 若爲薄於1奈米時，則不能充分發揮電流擴散功效。若超 過20奈米時，則將導致電流擴散層之光透射性顯著降低， 以致有發光輸出降低之顧慮。以1 〇奈米以下爲更佳。再進 一步使厚度成爲3〜6奈米範圍，即可使電流擴散層之光 透射性與電流擴散功效之平衡趨於最佳，若與上述接觸層 加在一起即可在正極上全面均勻地發光，且獲得高輸出的 發光。 -17- 1275190 若以透明材料形成電流擴散層時，其厚度較佳爲1 0〜 5,000奈米。若薄於1〇奈米時，則不能充分發揮電流擴散 功效。若超過5,〇〇〇奈米時，電流擴散層之光透射性則將 降低，以致有發光輸出降低之顧慮。因此，更佳爲50〜 2，000奈米。並且，再進一步設定厚度爲1〇〇〜1，〇〇〇奈米 範圍即可使電流擴散層之光透射性與電流擴散功效之平衡 趨於最佳，若與上述接觸層加在一起即可在正極上全面均 勻地發光，且獲得高輸出的發光。 ί 若在透光性電極上形成接合墊電極時，透光性電極之最 頂層也可爲金屬所覆蓋，也可爲金屬氧化物所覆蓋。 透光性電極之最頂層，也可爲電流擴散層，在電流擴散 層之上方也可形成供接合接合墊電極所需之層。惟經形成 接合所需之層即將導致透光性惡化，因此最頂層較佳爲電 流擴散層。 在透光性電極之最表面也可爲取出光而在面上賦予凹凸 。凹凸之形成可採用使用施加圖案製膜製程之方法或以濕 ^ 式處理形成凹凸之方法。凹凸之形狀可在無任何限制下使 用條紋狀或方格狀，點狀等之習知者。 此外，經由對具有如此之凹凸形狀的表面形成接合墊， 即可提高焊墊之密著強度。 關於接觸層及電流擴散層以及接合墊層電極之成膜方法 ，並無特殊限定，可使用習知的真空蒸鍍法或濺鍍法。 本發明之透光性正極，係可在不受到任何限制下使用如 同第1圖所示在基板上隔著緩衝層而積層氮化鎵系化合物 -18- 1275190 半導體、形成η型半導體層、發光層以及p型半導體層之 先前習知之含有氮化鎵系化合物半導體發光元件之半導體 發光元件。 基板可在不受到任何限制下使用··藍寶石單結晶（A1203 ;A面、C面、Μ面、R面）、尖晶石單結晶（MgAl204 ) 、ZnO單結晶、LiA102單結晶、LiGa02單結晶、MgO單結 晶等之氧化物單結晶；Si單結晶、SiC單結晶、GaAs單結 晶、A1N單結晶、GaN單結晶及ZrB2等之硼化物單結晶等 之基板材料。基板之面方位並無特殊限定。此外，也可爲 恰當（just )的基板也可，賦予偏移（off )角之基板也可 〇 η型半導體層、發光層及p型半導體層係可在不受到任 何限制下使用各種習知的結構。尤其是ρ型半導體層之載 體濃度雖然也可使用一般性濃度者，但是對於載體濃度較 低，本發明之透光性正極也可適用例如約lx 10 17 cm·3的ρ 型半導體層。 在本發明之用以構成η型半導體層、發光層及ρ型半導 體層之氮化鎵系化合物半導體，可在不受到任何限制下使 用以通式 AlxIriyGa^x-yN (0Sx<l、OSycl，OSx + y<l) 所代表之各種組成之半導體。 該等氮化鎵系化合物半導體之生長方法，並無特殊限定 ，可使用MOCVD (金屬有機化學氣相生長法）、HVPE ( 氫化氣相磊晶生長法）、MBE (分子束磊晶生長法）等之 習知的可供生長III族氮化物半導體之所有方法。較佳的生 -19- 1275190 長方法，若從膜厚控制性、量產性的觀點來考慮則爲 MOCVD法。在M0CVD法，載氣係使用氫氣（I)或氮氣 (& ) ’屬III族原料之Ga源係使用三甲基鎵（TMG )或 三乙基鎵（TEG ) 、A1源係使用三甲基鋁（TMA )或三乙 基鋁（TEA) 、In源係使用三甲基銦（TMI)或三乙基銦 (TEI )、氮源係使用氨氣（NH3 )、聯氨（n2H4 )等。此 外，關於摻質，對於η型，Si原料則使用單矽烷（SiH4 ) 或二矽烷（Si2H6 ) ，Ge原料則使用鍺烷（GeH4 );對於p • 型，Mg原料則使用例如雙環戊二烯基鎂（CP2Mg )或雙乙 基 戊—'嫌基錶（（EtCp)2Mg)。 爲使負極接於經在基板上將η型半導體層、發光層及p 型半導體層依此順序所積層的氮化鎵系化合物半導體之η 型半導體層上而加以形成，則須除去發光層及ρ型半導體 層之一部份，以使η型半導體層露出。其後則在其餘之ρ 型半導體層上形成本發明之透光性正極，在經露出的η型 半導體層上形成負極。負極有各種組成及結構者已爲眾所 ® 皆知，該等習知的負極可在不受到任何限制下使用。 若使用藍寶石或SiC (碳化矽）等之對發光波長爲呈透 明的基板之元件時，則也可在基板背面形成反射膜。當形 成反射膜時，即可減少在基板下面的光之損失，可使向外 部取出發光之效率更加提高，因此爲較佳。 此外，也可在半導體層、透明電極層、或基板背面等， 施加賦予凹凸加工，經由施加該加工也可提高向外部取出 發光之效率。加工係除形成對基板成垂直的面以外’也可 -20- 1275190 採取形成傾斜之面。就防止多次反射之目的而言，較佳爲 形成傾斜之面。 加工係除藉由削去上述半導體層、透明電極層、或基板 背面來施加之方法以外，也可採取將經以透明材料所構成 之結構物予以附著之方法。 若使用本發明之半導體發光元件用正極時，則可獲得高 發光強度之氣化録系化合物半導體發光兀件。亦即，由於 經由該技術即可製得高亮度LED燈，因此，經搭配由該技 術所製造之晶片的攜帶電話、顯示器、面板類等之電子機 器，或經搭配其電子機器之汽車、電腦、遊樂機等之機械 裝置類，即得以實現在低功率下之驅動，可實現高特性。 尤其是在攜帶電話、遊樂機、玩具、汽車零件等之電池驅 動方式之機器類中，即可發揮省電之功效。 《實施例》 茲以實施例將本發明更詳加說明，但是本發明並不受限 於此等實施例。 〔實施例1〕 第2圖係在本實施例所製造之氮化鎵系化合物半導體發 光元件之剖面模式圖，第3圖係其俯視模式圖。其係：在 由藍寶石所構成之基板（1 )上，隔著由A1N所構成之緩衝 層（6 )而將厚度爲8微米之由非摻雜的GaN所構成之基 底層（3a)，厚度爲2微米之摻Si的η型GaN接觸層（3b )，厚度爲250奈米之η型In0.iGa0.9N包層（3c) ’厚度 爲16奈米之摻Si的GaN阻障層及厚度爲2.5微米之 -21 - 1275190(24) The positive electrode for a semiconductor light-emitting device according to any one of the above items, wherein the transparent material is selected from the group consisting of indium tin oxide, zinc oxide, aluminum zinc oxide, and fluorine-doped tin oxide. At least one of a group consisting of titanium oxide, zinc sulfide, cerium oxide, and magnesium oxide. (25) The positive electrode for a semiconductor light-emitting device according to Item 24, wherein the transparent material is at least one selected from the group consisting of indium tin oxide, zinc oxide, zinc oxide sulphide, and fluorine-doped zinc oxide. (26) The positive electrode for a semiconductor light-emitting device according to any one of the items 10, 11, 13, and 23 to 25, wherein the transparent material has a thickness of 10 to 5,000 nm. (27) The positive electrode for a semiconductor light-emitting device according to Item 26, wherein the transparent material has a thickness of 100 to 1,000 nm. (28) A semiconductor light-emitting device using the positive electrode according to any one of items 1 to 27 above. (29) A gallium nitride-based compound semiconductor light-emitting device in which an n-type semiconductor layer, a light-emitting layer, and a germanium-type semiconductor layer composed of a gallium nitride-based compound semiconductor are sequentially disposed on a substrate, and a germanium-type semiconductor is provided In the light-emitting element in which the positive electrode-10-1275190 and the negative electrode are respectively provided on the layer and the n-type semiconductor layer, the positive electrode is the positive electrode according to any one of claims 1 to 27. (30) A lamp comprising the light-emitting element of item 28 or 29 above. By providing a reflective layer on at least the surface of the bonding pad electrode required to allow current to flow through the translucent electrode to be in contact with the translucent electrode, the surface of the bonding pad electrode and the translucent electrode can be reduced. The degree of attenuation of light caused by absorption of light can efficiently increase the efficiency of light extraction and increase the intensity of light. [Embodiment] BEST MODE FOR CARRYING OUT THE INVENTION Fig. 1 is a cross-sectional view showing an example of a light-emitting element having a positive electrode of the present invention. The positive electrode of the present invention is composed of a translucent electrode (1 1 ) and a bonding pad electrode (13). The translucent electrode (1 1 ) is composed of, for example, a contact layer (1 1 1 ) and a current diffusion layer (1 1 2 ). The bonding layer electrode (13) is composed of, for example, a three-layer structure of a reflective layer (1 3 1 ), a barrier layer (1 3 2 ), and a topmost layer (^1 3 3 ). 1 is a substrate. 2 is a GaN-based compound semiconductor layer composed of the n-type semiconductor layer 3, the light-emitting layer 4, and the p-type semiconductor layer 5. 6 is a buffer layer and 20 is a negative electrode. In the face-up type wafer having the light-transmitting positive electrode, the light emitted from the light-emitting layer (4) has only the light toward the translucent electrode portion where the pad electrode is not present and the light toward the side of the wafer. Can be taken out of the outside. When the positive electrode of the present invention is used, the light toward the bonding pad electrode (13) will be the reverse -11 - 1275190 emission layer at the bottom of the bonding pad electrode (the surface in contact with the translucent electrode) (1 3 1 Being reflected, a portion of it will scatter and travel in a lateral or oblique direction, with a portion traveling straight below the bond pad electrodes. Light that is scattered toward the lateral direction or oblique direction by the scattering is taken out from the side of the wafer. On the other hand, the light traveling toward the direction directly under the bonding pad electrode is scattered or reflected on the lower surface of the wafer, and is taken out to the outside via the side surface or the translucent electrode (the portion where the bonding pad electrode is not present). Thus, by providing a reflective layer at the bottom of the bonding pad electrode, it is possible to remove the light generated directly under the bonding pad electrode from the outside to maintain high luminous intensity. If there is light absorption at the bottom of the pad electrode, most of the light generated directly under the pad electrode will be absorbed at the bottom of the pad electrode so that it cannot be taken out. The reflective layer must be directly adhered to the translucent electrode as a condition required to exhibit the efficacy of the present invention. Therefore, if the bonding pad is to obtain sufficient strength, the reflective layer must be strongly adhered to the translucent electrode. At the very least, the step of attaching the gold wire to the bonding pad in a conventional manner is not allowed to be peeled off, so that it must have a strength of about 490 mN (50 gram force) in terms of peel strength. It is preferably 784 mN (80 gram force) or more, and more preferably 980 mN (100 gram force) or more. When it is desired to enhance the adhesion strength between the reflective layer and the translucent electrode, a method of improving the surface of the translucent electrode or applying a heat treatment or the like after forming the reflective layer may be employed. The reflectance of the reflective layer is largely changed by the constituent material of the reflective layer, but is preferably 60% or more, more preferably 80% or more, and particularly preferably -12 to 1275190 is 90% or more. The reflectance can be measured relatively easily by a device called a spectrophotometer or the like. However, since the bonding pad electrode itself is small in area, it is difficult to measure the reflectance. Therefore, a method in which a "dummy substrate" having a large transparent area such as glass is placed in the reaction chamber when the bonding pad electrode is formed, and the same bonding pad electrode is fabricated on the dummy substrate, and then measured, etc. To determine. Preferably, the reflective layer of the bonding pad electrode is made of a metal having a high reflectance, more preferably a platinum group metal such as Pt, Rh, Ru, Ir, or the like, and at least one of the metals. Alloy to form. Among them, A, Ag, Pt, and an alloy containing at least one of these metals are excellent in that they are easily obtained as a general material for an electrode and are easy to use. The bonding pad electrode is formed directly on the translucent electrode without forming a notch portion or a window portion of the translucent electrode. Since it is formed on the light-transmitting electrode, it is possible to prevent the driving voltage from rising without reducing the area where the ohmic contact is caused, or even if the contact resistance of the electrode is not increased immediately below the bonding pad electrode. Moreover, since the light transmitted through the translucent electrode is reflected at the lowermost reflective layer of the bonding pad electrode, the undesired absorption of light can be suppressed. The bonding pad electrode can be formed at any position as long as it is positioned above the translucent electrode. For example, it may be formed at a position farthest from the negative electrode, or may be formed at the center of the wafer or the like. However, if it is formed too close to the negative electrode, it will easily cause a short circuit between the wires and the ball during the bonding, so the -13 - 1275190 is not good. Further, the bonding pad electrode area is as large as possible, that is, the easier it is to perform the bonding work, but the light emission is prevented from being taken out. For example, if the area exceeding one-half of the area of the wafer surface is covered, the light emission is prevented from being taken out, and the output is remarkably lowered. Conversely, if it is too small, it is difficult to perform the joining work, so that the yield of the product is lowered. Specifically, it is preferably a reflective layer of a circular 〇B bond pad electrode having a diameter slightly larger than the diameter of the bonding ball, generally about 1 〇〇 micrometer (#m), if formed of a metal having high reflectivity. Preferably, the thickness is from 20 to 3,000 nm. If the reflective layer is too thin, a sufficient reflection effect cannot be obtained. When it is too thick, it does not produce special advantages, only causing long process time and wasted material. Therefore, it is more preferably 50 to 1,000 nm, and most preferably 100 to 500 nm. The pad electrode may be formed only of the metal having high reflectance as described above. That is, the pad electrode can be composed only of the reflective layer. However, the bonding pad electrodes are known to have various structures using various materials, and the above-mentioned reflective layer may be newly provided on the semiconductor layer side (translucent electrode side) of such conventional persons, and such a conventional method may be known. The lowermost layer on the side of the semiconductor layer is replaced by the above-mentioned reflective layer. In the case of such a laminated structure, the laminated structure portion located above the reflective layer is not particularly limited, and any structure can be used. For example, the layer formed over the reflective layer of the bonding pad electrode serves to enhance the overall strength of the bonding pad electrode. Therefore, it is necessary to use a relatively strong metal material or to make the film thickness a sufficient thickness. Preferred materials are Ti, Cr or A1. Among them, Ti is preferable from the viewpoint of material strength. When a function such as -14- 1275190 is imparted, the layer is referred to as a barrier layer. The barrier layer can also be used in combination with a reflective layer. If a metal material having a good reflectance and being mechanically strong is formed to be thick, it is not necessary to form a barrier layer. For example, when A1 is used as the reflective layer, it is not necessary to form a barrier layer. The thickness of the barrier layer is preferably from 20 to 3,000 nm. If the barrier layer is too thin, it will not be able to obtain sufficient strengthening strength, too thick to produce special advantages, but only cause an increase in cost. More preferably, the best of 5 0 to 1,000 nm is 100 to 500 nm. The topmost layer of the bonding pad electrode (the side opposite to the reflective layer) is preferably a material having good adhesion to the bonding ball. Most of the bonding balls are made of gold, and the metal with good adhesion to gold balls is known as Au and A1. Particularly good among them is gold. The thickness of the topmost layer is preferably 50 to 1, 〇〇〇 nanometer, and more preferably 100 to 500 nm. When it is too thin, the adhesion of the ball to the ball will deteriorate, and when it is too thick, it will not be particularly advantageous, and only the cost will increase. The preferred performance required for the translucent electrode formed on the semiconductor layer (P-type layer) includes a small contact resistance with the P-type layer, and faces up from the side of the electrode surface for taking out light from the light-emitting layer. The assembled type of light-emitting element is required to have excellent light transmittance and excellent conductivity required for uniformly dispersing current in the p-type layer. The translucent electrode is known to have various structures using various materials, and the conventional translucent electrode can be used without any limitation in the present invention. However, in order to meet the above-mentioned required performance conditions, it is preferable to transmit light of at least two layers of the -15-1275190 contact layer connected to the P-type layer and the current diffusion layer on the contact layer for assisting current diffusion. Sex electrode. Of course, as long as it can meet the above-mentioned required performance conditions, it can also be a layer of the function of the contact layer and the current diffusion layer. If a layer structure is adopted, there is no complicated process, and the performance required for the contact metal layer is required. The contact resistance with the P type must be small. From this point of view, the material of the contact layer is preferably platinum (Pt), ruthenium (Ru), hungry (Os), rhodium (Rh), iridium (Ir), palladium. (Pd) • Platinum metals or such alloys. Among these, Pt has a high work function, and it is particularly preferable that a relatively high-resistance p-type GaN-based compound semiconductor layer which is not subjected to high-temperature heat treatment can obtain excellent ohmic contact without heating. • When the contact metal layer is composed of a platinum group metal or an alloy containing the same, the thickness must be made very thin from the viewpoint of light transmittance. The thickness of the contact metal layer is preferably in the range of 0.1 to 7.5 nm. If it is thinner than 0.1 nm, it is difficult to obtain a stable thin layer. If it is thicker than 7.5 nm, the light transmittance will decrease, so it is preferably 5 nm or less. Further, in view of the decrease in light transmittance and the stability of film formation caused by the subsequent deposition of the current diffusion layer, it is particularly preferably in the range of 0.5 to 2. 5 nm. However, if the thickness of the contact metal layer is made thin, the surface resistance of the contact metal layer will increase, and interaction with the relatively high-resistance P-type semiconductor layer will cause the current to diffuse only to the pad of the current injection portion. As a result of the peripheral portion of the layer, there is a possibility that the uneven light-emitting mode is caused, and the light-emitting output is lowered. -16- 1275190 Therefore, as a method of supplementing the current diffusing property of the contact metal layer, if a current diffusion layer composed of a metal thin film having high light transmittance and high conductivity compared with the contact metal layer is disposed on the contact metal layer Thereby, the current can be uniformly diffused without causing a large damage to the low contact resistance or light transmittance of the platinum group metal, and as a result, a material having a high light-emitting output and a current diffusion layer can be obtained. A metal having high conductivity, for example, a metal selected from the group consisting of gold, silver, and copper or an alloy containing at least one of these. Among them, gold is preferred because it has a high light transmittance when it is made into a film. On the other hand, the material of the current diffusion layer can also be high-conductivity zinc sulfide and metal oxide, for example, indium tin oxide (ITO), ZnO, aluminum zinc oxide, fluorine-doped tin oxide, titanium oxide, oxidation. It is formed by a transparent material such as cerium or magnesium oxide. Such a transparent material is also preferable because its light transmittance is also high. Among them, indium tin oxide, ZnO, aluminum oxide zinc and fluorine-doped tin oxide are well known in terms of high conductivity, and therefore are preferred. When the current diffusion layer is formed of a metal, the thickness thereof is preferably from 1 to 20 nm. If it is thinner than 1 nm, the current spreading effect cannot be fully exerted. If it exceeds 20 nm, the light transmittance of the current diffusion layer is remarkably lowered, so that there is a concern that the light output is lowered. It is better to use 1 〇 or less. Further, the thickness is in the range of 3 to 6 nm, so that the balance between the light transmittance and the current diffusion efficiency of the current diffusion layer is optimized, and if the contact layer is added together, the light can be uniformly and uniformly emitted on the positive electrode. And obtain high output luminescence. -17- 1275190 When the current diffusion layer is formed of a transparent material, the thickness thereof is preferably from 10 to 5,000 nm. If it is thinner than 1 nanometer, the current spreading effect cannot be fully exerted. If it exceeds 5, when the nanometer is used, the light transmittance of the current diffusion layer will be lowered, so that there is a concern that the light output is lowered. Therefore, it is better for 50 to 2,000 nm. Moreover, the thickness is further set to 1 〇〇 〜1, and the 〇〇〇 nanometer range can optimize the balance between the light transmittance and the current diffusion efficiency of the current diffusion layer, and can be added together with the above contact layer. The light is completely uniformly emitted on the positive electrode, and high-output light emission is obtained. ί When the bonding pad electrode is formed on the translucent electrode, the topmost layer of the translucent electrode may be covered with metal or covered with a metal oxide. The topmost layer of the translucent electrode may also be a current spreading layer, and a layer required to bond the bonding pad electrodes may be formed over the current spreading layer. However, the layer required to form the bonding is likely to cause deterioration in light transmittance, so the uppermost layer is preferably a current diffusion layer. On the outermost surface of the translucent electrode, it is also possible to extract light and provide irregularities on the surface. The formation of the concavities and convexities may be carried out by a method of applying a pattern forming process or by a wet process. The shape of the concavities and convexities can be used by any conventional person such as a stripe shape, a square shape, or a dot shape without any restriction. Further, by forming a bonding pad on the surface having such a concavo-convex shape, the adhesion strength of the bonding pad can be improved. The film formation method of the contact layer, the current diffusion layer, and the bonding pad electrode is not particularly limited, and a conventional vacuum vapor deposition method or a sputtering method can be used. The translucent positive electrode of the present invention can be formed by laminating a gallium nitride-based compound-18-1275190 semiconductor on a substrate via a buffer layer as shown in FIG. 1 without any restriction, forming an n-type semiconductor layer, and emitting light. A conventional semiconductor light-emitting element containing a gallium nitride-based compound semiconductor light-emitting element of a layer and a p-type semiconductor layer. The substrate can be used without any restrictions. · Sapphire single crystal (A1203; A face, C face, face, R face), spinel single crystal (MgAl204), ZnO single crystal, LiA102 single crystal, LiGa02 single crystal An oxide single crystal such as MgO single crystal; a substrate material such as Si single crystal, SiC single crystal, GaAs single crystal, A1N single crystal, GaN single crystal, or boride single crystal such as ZrB2. The surface orientation of the substrate is not particularly limited. Further, the substrate may be an appropriate (just) substrate, and the substrate may be provided with an off angle. The n-type semiconductor layer, the light-emitting layer, and the p-type semiconductor layer may be used without any limitation. Structure. In particular, the carrier concentration of the p-type semiconductor layer may be a general concentration. However, for the carrier concentration of the p-type semiconductor layer, a p-type semiconductor layer of, for example, about 1 x 10 17 cm·3 can be applied. The gallium nitride-based compound semiconductor for constituting the n-type semiconductor layer, the light-emitting layer, and the p-type semiconductor layer of the present invention can be used without any limitation with the general formula AlxIriyGa^x-yN (0Sx<l, OSycl, OSx + y<l) semiconductors of various compositions. The method for growing the gallium nitride-based compound semiconductor is not particularly limited, and MOCVD (metal organic chemical vapor deposition), HVPE (hydrogenation epitaxial growth), and MBE (molecular beam epitaxy) can be used. And other conventional methods for growing a Group III nitride semiconductor. The preferred method of growth -19-1275190 is MOCVD when it is considered from the viewpoint of film thickness controllability and mass productivity. In the M0CVD method, the carrier gas system uses hydrogen (I) or nitrogen (& ) 'the source of the Group III raw material Ga source uses trimethylgallium (TMG) or triethylgallium (TEG), and the A1 source system uses the top three. Base aluminum (TMA) or triethyl aluminum (TEA), In source uses trimethyl indium (TMI) or triethyl indium (TEI), nitrogen source uses ammonia (NH3), hydrazine (n2H4), etc. . Further, regarding the dopant, for the n-type, the Si raw material uses monodecane (SiH4) or dioxane (Si2H6), the Ge raw material uses decane (GeH4), and for the p-type, the Mg raw material uses, for example, dicyclopentadiene. Magnesium (CP2Mg) or diethylpentyl-'s base table ((EtCp) 2Mg). In order to form the negative electrode on the n-type semiconductor layer of the gallium nitride-based compound semiconductor in which the n-type semiconductor layer, the light-emitting layer, and the p-type semiconductor layer are stacked on the substrate in this order, the light-emitting layer and the light-emitting layer must be removed. One portion of the p-type semiconductor layer exposes the n-type semiconductor layer. Thereafter, the light-transmitting positive electrode of the present invention is formed on the remaining p-type semiconductor layer, and the negative electrode is formed on the exposed n-type semiconductor layer. It is well known that the negative electrode has various compositions and structures, and such conventional negative electrodes can be used without any limitation. When an element such as sapphire or SiC (tantalum carbide) which is a transparent substrate is used, a reflective film can be formed on the back surface of the substrate. When the reflective film is formed, the loss of light under the substrate can be reduced, and the efficiency of taking out the light from the outside can be further improved, which is preferable. Further, it is also possible to apply unevenness processing to the semiconductor layer, the transparent electrode layer, or the back surface of the substrate, and the efficiency of taking out the light emission to the outside can be improved by applying the processing. The processing system may be formed by forming a slanted surface in addition to forming a plane perpendicular to the substrate -20- 1275190. For the purpose of preventing multiple reflections, it is preferred to form an inclined surface. In addition to the method of applying the semiconductor layer, the transparent electrode layer, or the back surface of the substrate, the processing may be carried out by attaching a structure made of a transparent material. When the positive electrode for a semiconductor light-emitting device of the present invention is used, a vaporized compound semiconductor light-emitting device having high light-emitting intensity can be obtained. That is, since a high-brightness LED lamp can be produced by this technology, an electronic device such as a mobile phone, a display, a panel, or the like, which is matched with a wafer manufactured by the technology, or a car or computer equipped with the electronic device thereof Mechanical devices such as amusement machines, such as driving at low power, can achieve high characteristics. In particular, in a machine type that uses a battery drive system such as a telephone, an amusement machine, a toy, or a car part, the power saving effect can be achieved. The present invention is described in more detail by way of examples, but the invention is not limited thereto. [Embodiment 1] Fig. 2 is a cross-sectional schematic view showing a gallium nitride-based compound semiconductor light-emitting device manufactured in the present embodiment, and Fig. 3 is a plan view schematically showing the same. A base layer (3a) made of undoped GaN having a thickness of 8 μm on a substrate (1) made of sapphire, via a buffer layer (6) made of A1N, thickness a 2 micron Si-doped n-type GaN contact layer (3b), a 250 nm thick n-type In0.iGa0.9N cladding layer (3c) '16 nm thick Si-doped GaN barrier layer and thickness For the 2.5 micron - 21 - 1475190
In0.2GaQ.8N井層予以積層5層，最後在將設置阻障層的多 重量子井結構之發光層（4)，厚度爲0.01微米之摻Mg的 p型Alo.G7GaG.93N包層（5a )，厚度爲〇 · 1 5微米之摻Mg 的p型GaN接觸層（5b )依此順序予以積層之氮化鎵系化 合物半導體之P型GaN接觸層上，形成厚度爲1.5奈米之 Pt接觸金屬層（1 1 1 )，厚度爲5奈米之Au電流擴散層（ 112)所構成之透光性電極（11)及50奈米之Pt層（13a )、20奈米之Ti層（13b) 、10奈米之A1層（13c)、 100奈米之Ti層（13d) 、200奈米之Au層（13e)所構成 之5層結構之接合墊電極（1 3 )所構成之本發明之正極（ 10)。在形成接合墊電極之5層中50奈米之Pt層（13a) 係相當於高反射率之反射層。然後在η型GaN接觸層上形 成Ti/Au之二層結構之負極（20)，以使光取出面位於半 導體側所構成之發光元件。正極及負極之形狀係如第3圖 所示者。 在該結構中，η型GaN接觸層之載體（carrier)濃度爲 1 X 1019/cηΓ3，GaN 阻障層之 Si 摻雜量爲 1 xlO1 8/cm·3，p 型 GaN接觸層之載體濃度爲5xl018/crrT3，p型AlGaN包層之 Mg 摻雜量爲 5xl019/cnT3。 該氮化鎵系化合物半導體之積層，係以MOCVD法，並 以在該技術領域中習知的通常條件實施。此外’正極及負 極係以下述順序形成。 起初，以反應性離子蝕刻法並以下述順序使供形成負極 部份之η型GaN接觸層露出。 -22- 1275190 首先，在P型半導體層上形成蝕刻掩模。形成順序如下 。經在全面均勻塗佈光阻劑後，使用習知的微影照相術， 從正極區域除去光阻劑。然後架設在真空蒸鍍裝置內，在 4x1 (Γ4 Pa以下之壓力以電子束法使Ni及Ti積層成膜厚分 別成爲約5 0奈米及3 00奈米。其後以剝落法技術與光阻劑 一起除去正極區域以外之金屬膜。 接著，將半導體積層基板載置於反應性離子蝕刻裝置之 蝕刻室內電極上，並使蝕刻室減壓至1 (Γ4 Pa後，供應作爲 • 蝕刻氣體之Cl2以施加蝕刻直至露出η型GaN接觸層爲止 。經蝕刻後，由反應性離子蝕刻裝置取出，以硝酸及氟酸 除去上述蝕刻掩模。 接著，使用習知的微影照相術及剝落法，僅在P型GaN 接觸層上之供形成正極之區域，形成由Pt所構成之接觸層 、由Au所構成之電流擴散層。接觸層、電流擴散層之形成 係首先將經積層氮化鎵系化合物半導體層之基板放入真空 蒸鍍裝置內，在P型GaN接觸層上最初將Pt積層1.5奈米 Φ ，其次將Au積層5奈米。接著，從真空室取出後，循通常 稱爲剝落法之習知的方法處理，再以相同方法在電流擴散 層上之一部份將由Pt所構成之反射層（13a)、由Ti所構 成之阻障層（13b)、由A1所構成之阻障層（13c)、由Ti 所構成之阻障層（13d)、由Au所構成之最頂層（13e)依 此順序予以積層，以形成接合墊電極（1 3 )。以此等方式 在p型GaN接觸層上形成本發明之正極。 然後，在經露出之η型GaN接觸層上以下述順序形成負 -23- 1275190 極。全面均勻地塗佈光阻劑後，使用習知的微影照相術， 由被露出的η型GaN接觸層上之負極形成部份除去光阻劑 後，以通常使用之真空蒸鍍法從半導體側依照順序形成Ti 爲100奈米、Au爲200奈米所構成之負極。其後則以習知 的方法除去光阻劑。 將經如此所形成正極及負極之晶圓，加以硏削·硏磨基 板背面，以使基板之板厚減薄至80微米，然後經使用雷射 劃線機從半導體積層側劃出割痕後予以按壓分割成3 5 0微 § 米見方之晶片。然後，以藉由探測針的通電來測定在施加 20 mA電流値時之正向電壓，結果爲2·9 V。 其後，安裝於TO-18罐盒型封裝，並以測試器測量發光 輸出結果，在施加電流爲2 0 m A時之發光輸出係顯現4.5 mW。此外，可確認到其發光面之發光分佈係在正極上全面 發光。 此外，經以本實施例所製造的反射層之反射率係在470 奈米波長區域爲92%。該値係使用在形成接合墊電極時放 # 在相同反應室內的玻璃製虛設基板，並以分光光度計所測 定。 此外，經以被稱爲剪切試驗器之一般性裝置測定接合墊 電極之剝離強度結果，平均爲980 mN ( 100克力）以上， 在接合墊電極與透明電極間並無剝離者。 〔比較例1〕 除在供形成接合墊電極之部份並未設置透光性電極，及 在接合墊電極未設置反射層（1 3a )以外，其餘則以與實施 -24- 1275190 例1相同地製造發光元件。因此在本比較例，其接合墊電 極之最下層（半導體側）爲由Ti所構成之層（13b )，且 其層係直接與P型接觸層（5b )相接。 此外，爲獲得接合墊電極與透光性電極之電氣接觸，則 採取使接合墊電極之周邊部會與透光性電極接觸之結構， 所接觸之面積係設定爲接合墊電極面積之約5 %。因此電流 將通過該接觸部而由接合墊電極流入於透光性電極。 將經獲得之發光元件與實施例1相同地加以評估，結果 • 正向電壓爲3·1 V，發光輸出爲4.2 mW。此外，確認到其 發光面之發光分佈係在接合墊電極正下方並未發光。其係 表示Ti係比較Pt爲與p型接觸層（5b)的接觸電阻爲高 ，反射率爲低。 〔實施例2〕 除變更透光性電極（11)之Pt接觸層（111)厚度爲i 奈米，並變更電流擴散層（1 1 2 )爲經以濺鍍法所形成之厚 度爲100奈米之鋼錫氧化物，以及使用A1來形成接合塾電 # 極（1 3 )之反射層（1 3 a )以外，其餘則以與實施例1相同 地製造發光元件。 將經獲得之發光元件以與實施例1相同地加以評估結果 ，正向電壓爲2.9V，發光輸出爲5.0 mW。 此外，經以被稱爲剪切試驗器之一般性裝置測定接合墊 電極之剝離強度結果，平均爲9 8 0 mN ( 1 0 0克力）以上， 剝離在接合墊電極與透明電極間產生之試料則有數個。 〔比較例2〕 -25- 1275190 除並未5又置接合墊電極（13)之反射層（i3a)以外，其餘 則以與貫施例2相同地製造發光元件。將經獲得之發光元件 以與實施例1相同地加以評估，結果正向電壓爲29 V，雖然 與實施例2相同地爲低，但是發光輸出卻降低爲4.7 m W。 〔實施例3〕 在實施例3則以與實施例丨相同方法製造具有如下列積 層結構之磊晶基板來使用。亦即，在由藍寶石所構成之基 板（1 )上，隔著由A1N所構成之緩衝層（6 )，將厚度6 微米之由非摻雜的GaN所構成之基底層（3a)、厚度爲4 微米之摻Ge的n型GaN接觸層（3b)、厚度爲180奈米 之摻雜Si的η型InuGaojN包層（3c )、厚度爲16奈米 之摻Si的GaN障壁層、以及厚度爲2.5奈米之In〇.2Ga〇.8N 井層予以積層5次，最後將設置障壁層的多重量子井戸結 構之發光層（4)、厚度爲 0.01微米之摻Mg的p型 Al〇.G7Ga().93N包層（5a)、厚度爲0.175微米之摻Mg的p 型A 1G.()2 Ga〇. 98N接觸層（5b)依此順序積層，最後將摻Ge 的η型GaN隧道層（未圖示）形成20奈米。在η型GaN 隧道層氮化鎵系化合物半導體上，形成由厚度爲250奈米 之僅由銦錫氧化物（ITO )電流擴散層（1 1 2 )所構成之透 光性電極（11)及由50奈米之A1層（13a) 、20奈米之The In0.2GaQ.8N well layer is laminated with 5 layers, and finally, the luminescent layer (4) of the multiple quantum well structure in which the barrier layer is to be provided, and the Mg-doped p-type Alo.G7GaG.93N cladding layer having a thickness of 0.01 μm (5a) a p-type GaN contact layer (5b) having a thickness of 〇·15 μm and a P-type GaN contact layer of a gallium nitride-based compound semiconductor laminated in this order to form a Pt contact having a thickness of 1.5 nm a metal layer (1 1 1 ), a translucent electrode (11) composed of a 5 nm Au current diffusion layer (112), a 50 nm Pt layer (13a), and a 20 nm Ti layer (13b) The present invention comprising a 5-layer structure bonding pad electrode (13) composed of a 10 nm A1 layer (13c), a 100 nm Ti layer (13d), and a 200 nm Au layer (13e) The positive electrode (10). The 50 nm Pt layer (13a) in the five layers forming the bond pad electrode corresponds to a highly reflective reflective layer. Then, a negative electrode (20) of a two-layer structure of Ti/Au is formed on the n-type GaN contact layer so that the light extraction surface is located on the light-emitting element formed on the semiconductor side. The shapes of the positive electrode and the negative electrode are as shown in Fig. 3. In this structure, the carrier concentration of the n-type GaN contact layer is 1×1019/cηΓ3, the Si doping amount of the GaN barrier layer is 1×10 1/cm·3, and the carrier concentration of the p-type GaN contact layer is 5xl018/crrT3, the Mg doping amount of the p-type AlGaN cladding layer is 5xl019/cnT3. The laminate of the gallium nitride-based compound semiconductor is carried out by the MOCVD method under the usual conditions well known in the art. Further, the positive electrode and the negative electrode are formed in the following order. Initially, the n-type GaN contact layer for forming the negative electrode portion was exposed by reactive ion etching in the following order. -22- 1275190 First, an etching mask is formed on the P-type semiconductor layer. The order of formation is as follows. After the photoresist is completely uniformly coated, the photoresist is removed from the positive electrode region using conventional lithography. Then, it is placed in a vacuum evaporation apparatus, and the film thicknesses of the Ni and Ti layers are respectively reduced to about 50 nm and 300 nm by electron beam method at a pressure of 4×1 (Γ4 Pa or less). Thereafter, the peeling method and light are used. The resist removes the metal film other than the positive electrode region. Next, the semiconductor laminate substrate is placed on the etching chamber electrode of the reactive ion etching apparatus, and the etching chamber is decompressed to 1 (Γ4 Pa, and supplied as an etching gas). Cl2 is applied by etching until the n-type GaN contact layer is exposed. After etching, it is taken out by a reactive ion etching apparatus, and the etching mask is removed by nitric acid and hydrofluoric acid. Next, using conventional lithography and peeling methods, A contact layer made of Pt and a current diffusion layer made of Au are formed only in a region on the P-type GaN contact layer where a positive electrode is formed. The contact layer and the current diffusion layer are first formed by a laminated gallium nitride system. The substrate of the compound semiconductor layer was placed in a vacuum evaporation apparatus, and Pt was initially laminated to a thickness of 1.5 nm on the P-type GaN contact layer, and then Au was laminated to 5 nm. Then, after being taken out from the vacuum chamber, it was generally called According to the conventional method of the peeling method, a reflective layer (13a) composed of Pt, a barrier layer (13b) composed of Ti, and a layer A1 are formed in a part of the current diffusion layer in the same manner. A barrier layer (13c), a barrier layer (13d) composed of Ti, and a topmost layer (13e) composed of Au are laminated in this order to form a bonding pad electrode (13). A positive electrode of the present invention is formed on the p-type GaN contact layer. Then, a negative -23 to 1275190 electrode is formed on the exposed n-type GaN contact layer in the following order. After the photoresist is uniformly applied uniformly, a conventional micro is used. Photographic processing, after removing the photoresist from the negative electrode forming portion on the exposed n-type GaN contact layer, the Ti is formed to be 100 nm from the semiconductor side in the usual vacuum evaporation method, and Au is 200 nm. The negative electrode is formed. Thereafter, the photoresist is removed by a conventional method. The wafer of the positive electrode and the negative electrode thus formed is honed and honed to the back surface of the substrate to reduce the thickness of the substrate to 80 μm. And then using a laser marking machine to draw a cut from the side of the semiconductor laminate Press the wafer divided into 3 50 μ § m square. Then, the forward voltage when a current of 20 mA was applied was measured by energization of the probe pin, and the result was 2·9 V. Thereafter, it was mounted on TO- The 18-bar type package was used to measure the illuminating output with a tester, and the illuminating output showed 4.5 mW when the current was applied at 20 m A. In addition, it was confirmed that the illuminating distribution of the illuminating surface was completely illuminating on the positive electrode. Further, the reflectance of the reflective layer produced in the present embodiment is 92% in the wavelength region of 470 nm. This tantalum system uses a glass dummy substrate which is placed in the same reaction chamber when forming the bonding pad electrode, and Determined by a spectrophotometer. Further, the peel strength of the bonding pad electrode was measured by a general apparatus called a shear tester, and the average value was 980 mN (100 gram force) or more, and there was no peeling between the bonding pad electrode and the transparent electrode. [Comparative Example 1] Except that the translucent electrode was not provided in the portion where the bonding pad electrode was formed, and the reflective layer (13a) was not provided in the bonding pad electrode, the rest was the same as in Example No. -24-1295190 A light-emitting element is manufactured. Therefore, in this comparative example, the lowermost layer (semiconductor side) of the bonding pad electrode is a layer (13b) composed of Ti, and the layer is directly in contact with the P-type contact layer (5b). Further, in order to obtain electrical contact between the bonding pad electrode and the translucent electrode, a structure is adopted in which the peripheral portion of the bonding pad electrode is in contact with the translucent electrode, and the contact area is set to be about 5% of the bonding pad electrode area. . Therefore, a current flows through the contact portion and flows into the translucent electrode from the bonding pad electrode. The obtained light-emitting element was evaluated in the same manner as in Example 1. As a result, the forward voltage was 3·1 V, and the light-emitting output was 4.2 mW. Further, it was confirmed that the light-emitting surface of the light-emitting surface was not illuminated immediately below the bonding pad electrode. This indicates that the Ti-based comparison Pt has a high contact resistance with the p-type contact layer (5b) and a low reflectance. [Example 2] The thickness of the Pt contact layer (111) of the translucent electrode (11) was changed to i nm, and the current diffusion layer (1 1 2 ) was changed to have a thickness of 100 nm by sputtering. A light-emitting element was produced in the same manner as in Example 1 except that the tin oxide of rice was used, and the reflective layer (13 a ) of the junction electrode (1 3 ) was formed using A1. The obtained light-emitting element was evaluated in the same manner as in Example 1, and the forward voltage was 2.9 V, and the light-emitting output was 5.0 mW. Further, the peel strength of the bonding pad electrode was measured by a general device called a shear tester, and the average value was 980 mN (100 g force) or more, and peeling occurred between the bonding pad electrode and the transparent electrode. There are several samples. [Comparative Example 2] -25 - 1275190 A light-emitting device was produced in the same manner as in Example 2 except that the reflective layer (i3a) of the pad electrode (13) was not placed. The obtained light-emitting element was evaluated in the same manner as in Example 1. As a result, the forward voltage was 29 V, which was low as in Example 2, but the light-emitting output was lowered to 4.7 mW. [Example 3] In Example 3, an epitaxial substrate having the following laminated structure was produced in the same manner as in Example 来. That is, a base layer (3a) made of undoped GaN having a thickness of 6 μm and a thickness of 6 μm on the substrate (1) made of sapphire is sandwiched by a buffer layer (6) made of A1N. a 4 micron Ge-doped n-type GaN contact layer (3b), a 180 nm thick Si-doped n-type InuGaojN cladding layer (3c), a 16 nm thick Si-doped GaN barrier layer, and a thickness of The 2.5 nm In〇.2Ga〇.8N well layer is laminated 5 times. Finally, the light-emitting layer (4) of the multi-quantum well structure with the barrier layer and the Mg-doped p-type Al〇.G7Ga with a thickness of 0.01 μm are placed. The .93N cladding layer (5a), the Mg-doped p-type A 1G.() 2 Ga〇. 98N contact layer (5b) having a thickness of 0.175 μm is laminated in this order, and finally the Ge-doped n-type GaN tunnel layer is Not shown) formed 20 nm. On the n-type GaN tunnel layer gallium nitride-based compound semiconductor, a translucent electrode (11) composed of an indium tin oxide (ITO) current diffusion layer (1 1 2 ) having a thickness of 250 nm and a thin film is formed. From 50 nm A1 layer (13a), 20 nm
Ti層（13b) 、10奈米之A1層（。(^ ^(^奈米之^層 (13d) 、200奈米之Au層（13e)所構成之5層結構之接 合墊電極（1 3 )所構成之本發明之正極（1 0 ) °在形成接 合墊電極之5層中50奈米之Pt層（13a)係相當於筒反射 率之反射層。然後在n型GaN接觸層上形成Ti/A11之一層 -26- 1275190 結構之負極（20 )，以使光取出面位於半導體側所構成之 發光元件。正極及負極之形狀係如第3圖所示者。 在該結構中，n型GaN接觸層之載氣濃度爲8xl018 cnT3 ，η型InGaN包層之Si摻雜量爲7xl018 cm·3，GaN障壁層 之Si摻雜量爲lxl〇17 cnT3，p型AlGaN接觸層之載體濃度 爲5χ1017 crrT3，p型AlGaN包層之Mg摻雜量爲2χ102() cnT3。此外，η型GaN隧道層之Ge摻雜量係設定爲2x1 019 cm'3 ° φ 將經獲得之發光元件以與實施例1相同地加以評估，結 果正向電壓爲3.2 V，發光輸出爲8.5 mW。 此外，經以被稱爲剪切試驗器之一般性裝置測定接合墊 電極之剝離強度結果，平均爲1 00克力以上，剝離在接合 墊電極與透明電極間產生之試料則有數個。 〔產業上之利用性〕 使用本發明之正極所提供之半導體發光元件，其驅動電 壓低，且發光強度高，因此非常適合用作爲燈等之材料。 【圖式簡單說明】 第1圖係展示具有本發明透光性正極之發光元件一實例 剖面模式圖。 第2圖係展示具有經以實施例1所製得之本發明透光性 正極之氮化鎵系化合物半導體發光元件剖面模式圖。 第3圖係展示具有經以實施例所製得之本發明透光性正 極之氮化鎵系化合物半導體發光元件俯視模式圖。 【主要元件符號說明】 1 基板 -27- 1275190Bonding pad electrode of 5-layer structure composed of Ti layer (13b), 10 nm A1 layer (. ^^(^ nanometer layer (13d), 200 nm Au layer (13e)) (1 3 The positive electrode (10) of the present invention is composed of a 50 nm Pt layer (13a) in a layer of 5 layers forming a bonding pad electrode, which corresponds to a reflective layer of a cylindrical reflectance, and then formed on the n-type GaN contact layer. The negative electrode (20) of the Ti/A11 layer -26-1275190 structure is such that the light extraction surface is located on the semiconductor side. The shape of the positive electrode and the negative electrode is as shown in Fig. 3. In this structure, n The carrier gas concentration of the GaN contact layer is 8xl018 cnT3, the Si doping amount of the n-type InGaN cladding layer is 7xl018 cm·3, the Si doping amount of the GaN barrier layer is lxl〇17 cnT3, and the carrier concentration of the p-type AlGaN contact layer For 5χ1017 crrT3, the Mg doping amount of the p-type AlGaN cladding layer is 2χ102() cnT3. In addition, the Ge doping amount of the n-type GaN tunnel layer is set to 2x1 019 cm'3 ° φ to obtain the obtained light-emitting element Example 1 was evaluated in the same manner, and the forward voltage was 3.2 V, and the luminous output was 8.5 mW. Furthermore, it was measured by a general device called a shear tester. As a result of the peeling strength of the pad electrode, the average is 100 gram or more, and there are several samples which are peeled off between the pad electrode and the transparent electrode. [Industrial Applicability] The semiconductor light-emitting element provided by using the positive electrode of the present invention The driving voltage is low and the luminous intensity is high, so it is very suitable as a material for a lamp or the like. [Schematic Description of the Drawing] Fig. 1 is a schematic cross-sectional view showing an example of a light-emitting element having the light-transmitting positive electrode of the present invention. The figure shows a cross-sectional schematic view of a gallium nitride-based compound semiconductor light-emitting device having the light-transmitting positive electrode of the present invention obtained in Example 1. FIG. 3 is a view showing the light-transmitting of the present invention obtained by the embodiment. Top view of a gallium nitride-based compound semiconductor light-emitting device of a positive electrode. [Description of main components] 1 Substrate-27- 1275190
2 GaN系化合衫 3 η型半導體層 3 a 基底層 3b 摻Si的n型 3c n 型 In〇.! Ga〇. 4 發光層 5 P型半導體層 5a 摻Mg的p型 5b 摻Mg的p型 6 緩衝層 10 正極 11 透光性電極 13 接合墊電極 13a Pt層 13b Ti層 13c A1層 13d Ti層 1 3e Au層 20 負極 111 接觸層 1 12 電流擴散層 13 1 反射層 132 緩衝層 133 最頂層 丨半導體2 GaN-based compound shirt 3 n-type semiconductor layer 3 a base layer 3b Si-doped n-type 3c n-type In〇.! Ga〇. 4 light-emitting layer 5 P-type semiconductor layer 5a Mg-doped p-type 5b Mg-doped p-type 6 Buffer layer 10 Positive electrode 11 Translucent electrode 13 Bond pad electrode 13a Pt layer 13b Ti layer 13c A1 layer 13d Ti layer 1 3e Au layer 20 Negative electrode 111 Contact layer 1 12 Current diffusion layer 13 1 Reflection layer 132 Buffer layer 133 Top layer Semiconductor
GaN接觸層 9N包層 A1 〇. 〇 7 G a 〇. 9 3 N 包層 GaN接觸層 -28-GaN contact layer 9N cladding A1 〇. 〇 7 G a 〇. 9 3 N cladding GaN contact layer -28-