200840087 九、發明說明：- 【發明所屬之技術領域】 本發明係有關一種四元發光二極體製造方法’旨在提 供一種可增加發光效率之四元發光二極體製造方法。 【先前技術】 按，由於發光二極體與傳統燈泡比較具有絕對的優 勢’例如體積小、壽命長、低電壓/電流驅動、不易破裂、 φ 發光時無顯著之問題、不含水銀（沒有污染問題）、發光效 率佳（省電）等特性，且近幾年來發光二極體的發光效率不 斷提升，因此發光二極體在某些領域已漸漸取代日光燈與 白熱燈泡’例如需要局速反應的掃描器燈源、液晶顯示器 的背光源或前光源汽車的儀表板照明、交通號誌燈以及一 般的照明裝置等。 ， 而且’由於含氮之111 族化合物為一寬頻帶能隙之 材料’其發光波長可以從紫外光一直涵蓋至紅光，可說是 Φ 幾乎涵蓋整個可見光的波段。因此，利用含氮化鎵的化合 物半導體，如氮化鎵（GaN)、氮化鋁鎵（GaA1N)、氮化_ (GalnN)，磷化鋁銦鎵WlGaInP)等的發光二極體元件以廣 泛地應用在各種發光模組中。 ^ 而習知的發光二極體其上層表面是平面狀，且與其相 對的基板底面是相互的平行面。如此，當發光時部分光線 出射於元件的外部，另外有大部分光線會產生全 絲 ===射縣不佳。這是因為半導體材料相對於外部 二；；"為尚折射材料，因此，當光線出射的角度大於 5 200840087 一個臨界角時，便會發生全反射。發生全反射的光線，由 於發光二極體中相對的兩邊呈平行之平面，致使全反射的 光線永遠無法出射至外部，不但光線的出射效率差，同 時，全反射光在發光二極體内部產生熱能，彳吏得發光二極 體整體溫度升高，而不利於產品之可靠度要求。 而習有發光二極體例如四元發光二極體之結構，如第 一圖所示，該基板1 1 (如GaAs基板)上依序製作有緩衝 層1 2、第一型蠢晶層1 3、活性層1 4以及第二型遙晶 • 層1 5，而第二型磊晶層1 5表面設有電極1 6，而該基 板1 1底面則充當底面電極1 7,其基板1 1與第二型磊 曰曰層1 5之表面均為平面狀且近似相互平行；其四元發光 一極體係全面性發光，為這種全面性發光之面光源可以視 為疋無限多之點光源P所構成的，第二圖所示係以單一點 光源P做為範例說明，其顯示點光源p射出光線^、” 至70件外部，在出射光線PI、P2以外的光線，例如出射 光線P3、P4 ’則因為全反射的關係，不會出射到四元發 ⑩光二極體外部，或者經由内部幾次反射後才折射至四元發 光極體外邛，降低光源使用率，進而使整體四元發光_二 極體之光線出射效率降低。 【發明内容】 出二供一種可將因全反射而無法 使得光線在規則變化的光線進行方向’ _人折射或疋極少數幾次反射再折射之後，便 6 200840087 可以出射至四元發光二極體外部’而得到較高的光線 效率之四元發光二極體製造方法。 為達上述目的’本發明中四元發光二極體之基板上依 序設有緩衝層、第—料晶層、活性層以及第二型蠢晶 層’其第二型蠢晶層表面係彻粗糙化處理而形成有粗化 表面’該粗齡處理制㈣韻、贿以及缝酸以特定 比例混合後，由該混合液體浸洗該第二型蠢晶層表面，其 第二型蠢晶層則形成有複數週期性排列之凹部，藉由該凹 =將全反射而無法出射的光線直接折射，進而增加發光 效率。 【實施方式】 為能使貴審查委員清楚本私明* 以及實施方式，兹配合圖式說明如x下：主要技術内容，. 本1¾明四元發光二極體製方 該四元發光二極體2之製造方法係’小」’如第三圖所不， 板，於該基板上形成緩衝層，並’床）包含有··提供一基 第一型磊晶層、活性層以及第石於緩衝層上方形成有 晶層上經粗糙化處理形成粒化蟲晶層’而該第二塑磊 而製成之四元發光二極體結=如 包含有： 再如弟四圖所示，係至少 一基板2 1，其基板2 i 板2 1可以為GaAs基板。 设置有緩衝層2 2，該基 一緩衝層22 ’係設置於該基板2 !上。 7 200840087 一第一型磊晶層2 3，係設置於緩衝層2 2上方，其 第一型遙晶層2 3係包含有第一、二、三、四材料層2 3 1、2 3 2、2 3 3、2 3 4，請同時參閱第五圖所示， 其第一、二、三、四材料層2 3 1、2 3 2、2 3 3、2 3 4可以分別為η型磷化銦鎵磊晶層（GalnP)、η型砷化 鎵磊晶層（GaAs)、η型磷化鋁銦鎵磊晶層（AlGalnP)、η 型石粦化铭銦蟲晶層（A 11ηΡ)。 一活性層2 4，係設置於第一型磊晶層2 3上方，可 ⑩ 以為MQW(多重量子井）。 一第二型磊晶層2 5，係設置於活性層2 4上方，該 第二型磊晶層2 5係包含有第一、二材料層2 5 1、2 5 2，請同時參閱第六圖所示，其第一、二材料層2 5 1、 2 5 2可以分別為ρ型構化紹銦遙晶層（A1 InP)以及ρ型 磷化鎵磊晶層（GaP)，其中該第二型磊晶層2 5表面係具 有粗化表面2 8。 二電極2 6、2 7，係分別設置於第一型磊晶層2 3 φ 與基板21之底面。 其中，該粗糙化處理，如第七圖所示，係包含有下"列 步驟： 提供破酸、硫酸以及氫氟酸。 將碘酸、硫酸以及氫氟酸依照2 ·· 1 ·· 1之比例混合。 將混合液體於該第二型磊晶層2 5之表面進行浸 洗，並進行蝕刻作用，以完成粗化表面2 8，如第八圖所 示，該粗化表面2 8係具有複數凹入第二型磊晶層2 5表 8 200840087 面之凹部2 8 1。 具體實施時，如第九圖所示，同樣係以單一點光源p 做為範例說明，其顯示點光源P射出光線Pi、P2至四元 發光二極體外部，在出射光線Pi、P2以外的光線，例如 原來發生全反射之出射光線P3、P4 ’在這個圖示中經由 第二型磊晶層2 5之粗化表面2 8改變其入射角度，使其 入射角度小於全反射角度’而使光線直接折射至四元發光 二極體外部，圖中也顯示’若有極少部份之光線出射至四 % 元發光二極體之垂直邊側時，會於四元發光二極體形成一 次或以上之反射後，同樣可以直接由粗化表面2 8出射至 四元發光二極體外部，因此顯然可提高光線出射之效果； 而本發明之四元發光二極體可以將改變光線之折射角 度，使光線不會產生而直接折射之後出射至四元發光二極 體之外部，對整體而言，可顯著提高四元發光二極體之發 光效率。 另外，亦可於第一型磊晶層2 3與緩衝層2 2間設有 _ 一分佈布拉格反射層3 1，可將活性層2 4向下發出的 光，大部分再反射上去，增加整體四元發光二極體的尤源 取出效果，如第十圖所示，以及於第二型磊晶層2 5上方 進-步設有-窗口層32,其窗口層32可作電流分佈以 及光源取出之用，而於窗口層3 2表面形成粗化表面2 8 ’同樣可以達到提高四元發光二極體發光效率之功能。 如士斤述本务明提供一種較佳可行之四元發光二極 體及其製造方法，爰依法提呈發明專利之申請；惟，以上 9 200840087 之實施說明及圖式所示，係本發明較佳實施例者，並非以 此侷限本發明，是以，舉凡與本發明之構造、裝置、特徵 等近似、雷同者，均應屬本發明之創設目的及申請專利範 圍之内。 ‘ 【圖式簡單說明】 第一圖係為習知四元發光二極體結構之剖面示意圖。 第二圖係為習知光線出射效果之示意圖。 φ 第三圖係為本發明中四元發光二極體之製造方法步驟示 意圖。 第四圖係為本發明中第一型磊晶層之示意圖。 第五圖係為本發明中第二型磊晶層之示意圖。 第六圖係為本發明中四元發光二極體結構之剖面示意圖。 第七圖係為本發明中粗糙化處理之步驟示意圖。 ^ 第八圖係為本發明中粗糙化處理之結構示意圖。 第九圖係為本發明中光線出射效果之示意圖。 Φ 第十圖係為本發明中四元發光二極體結構之另一剖面示 意圖。 一 【主要元件代表符號說明】 1 四元發光二極體 1 1 —基板 1 2--緩衝層 13——第一型磊晶層 200840087 14——活性層 14 1一光線出射範圍 15 --第二型蠢晶層 16 --電極 1 7--電極 2 -----四元發光二極體 2 1 ——基板 2 2--緩衝層 ^ 23--第一型蠢晶層 2 3 1一第一材料層 2 3 2—第二材料層 2 3 3—第三材料層 2 3 4—第四材料層 2 4——活性層 25——第二型蠢晶層 2 5 1一第一材料層 2 5 2—第二材料層 2 6 —-一電極 2 7--電極 28--粗化表面 2 8 1—凹部 31--分佈布拉格反射層 3 2--窗口層 11200840087 IX. DESCRIPTION OF THE INVENTION: - Technical Field of the Invention The present invention relates to a method for fabricating a quaternary light-emitting diode, which is intended to provide a method for fabricating a quaternary light-emitting diode which can increase luminous efficiency. [Prior Art] Press, because the light-emitting diode has an absolute advantage compared with the conventional light bulb', for example, small size, long life, low voltage/current drive, not easy to break, no significant problems when φ illuminates, no mercury (no pollution) Problems), good luminous efficiency (power saving), etc., and the luminous efficiency of the light-emitting diodes has been increasing in recent years, so the light-emitting diodes have gradually replaced fluorescent lamps and white-hot bulbs in some fields, such as the need for a speed response. Scanner light source, backlight of liquid crystal display or instrument panel illumination of front light source car, traffic signal light and general lighting device. And because the nitrogen-containing 111-group compound is a material with a wide band gap, its emission wavelength can be covered from ultraviolet light to red light, and it can be said that Φ covers almost the entire visible light band. Therefore, a gallium nitride-containing compound semiconductor such as gallium nitride (GaN), aluminum gallium nitride (GaA1N), nitrided (GalnN), aluminum indium gallium phosphide (Wal GaInP), etc. It is used in various lighting modules. ^ The conventional light-emitting diode has a planar surface on its upper surface, and the opposite surfaces of the substrate are parallel surfaces. Thus, when the light is emitted, part of the light is emitted outside the component, and most of the light will produce a full wire === poor shooting. This is because the semiconductor material is opposite to the external two;;" is a refraction material, so when the angle of light emission is greater than a critical angle of 5 200840087, total reflection occurs. The total reflected light rays, because the opposite sides of the light-emitting diodes are parallel planes, so that the totally reflected light can never be emitted to the outside, not only the light emission efficiency is poor, but also the total reflected light is generated inside the light-emitting diode. Thermal energy, the overall temperature of the LED is increased, which is not conducive to the reliability requirements of the product. The structure of the light-emitting diode, such as a quaternary light-emitting diode, is as shown in the first figure. The substrate 11 (such as a GaAs substrate) is sequentially formed with a buffer layer 12. The first type of stray layer 1 3. The active layer 14 and the second type of remote crystal layer 15 are provided, and the surface of the second type epitaxial layer 15 is provided with an electrode 16 and the bottom surface of the substrate 1 1 serves as a bottom electrode 17 and a substrate 1 1 The surface of the second type of protrusion layer 15 is planar and approximately parallel to each other; the quaternary light-emitting one-pole system emits comprehensive light, and the surface light source of the comprehensive illumination can be regarded as an infinite number of point light sources. The second figure shows a single point light source P as an example, which shows that the point source p emits light, "to 70 outside, and the light outside the outgoing rays PI, P2, such as the outgoing light P3. P4', because of the total reflection, will not be emitted to the outside of the quaternary 10-light diode, or will be refracted to the quaternary illuminator outside the body after several reflections inside, reducing the light source usage, and thus making the overall quaternary The light-emitting efficiency of the light-emitting diode is lowered. After the total reflection can not make the light in the regular direction of the light 'direction _ human refraction or a few reflections and re-refraction, then 6 200840087 can be emitted to the outside of the quaternary light-emitting diode' and get higher A light-emitting quaternary light-emitting diode manufacturing method. For the above purpose, the buffer layer, the first seed layer, the active layer and the second type of stray crystal are sequentially disposed on the substrate of the quaternary light-emitting diode of the present invention. The layer 'the second type of stupid layer surface is completely roughened to form a roughened surface'. After the coarse processing system (4) rhyme, bribe, and sewn acid are mixed in a specific ratio, the second type is dipped by the mixed liquid. On the surface of the stupid layer, the second type of stray layer is formed with a plurality of periodically arranged concave portions, and the concave light is directly refracted by the light which is totally reflected and can be emitted, thereby increasing the luminous efficiency. Your reviewer is aware of this privacy* and the implementation method. It is accompanied by a schema description such as x: main technical content. This 13⁄4 Ming quaternary light-emitting diode system is a manufacturing method for the quaternary light-emitting diode 2 " As shown in the third figure, the plate forms a buffer layer on the substrate, and the 'bed' includes a base-type epitaxial layer, an active layer, and a second layer formed on the crystal layer above the buffer layer. The quaternary light-emitting diode junction formed by the roughening treatment to form the granulated worm layer and the second plastic ray = if included: as shown in the fourth figure, at least one substrate 2 1, the substrate 2 The i board 2 1 may be a GaAs substrate. A buffer layer 22 is provided, which is provided on the substrate 2!. 7 200840087 A first type of epitaxial layer 2 3 is disposed above the buffer layer 2 2 , and the first type of the crystal layer 2 3 includes the first, second, third and fourth material layers 2 3 1 , 2 3 2 2 3 3, 2 3 4, please also refer to the fifth figure, the first, second, third and fourth material layers 2 3 1 , 2 3 2, 2 3 3, 2 3 4 can be η-type phosphorus Indium gallium epitaxial layer (GalnP), n-type gallium arsenide epitaxial layer (GaAs), n-type aluminum indium gallium delphie epitaxial layer (AlGalnP), η-type 粦石化铭Indium worm layer (A 11ηΡ) . An active layer 24 is disposed above the first type epitaxial layer 23, and may be an MQW (multiple quantum well). A second type of epitaxial layer 25 is disposed above the active layer 24, and the second type of epitaxial layer 25 includes the first and second material layers 2 5 1 and 2 5 2, please refer to the sixth As shown in the figure, the first and second material layers 2 5 1 , 2 5 2 may be a p-type structured indium ingot layer (A1 InP) and a p-type gallium arsenide epitaxial layer (GaP), respectively. The surface of the type 2 epitaxial layer 25 has a roughened surface 28 . The two electrodes 2 6 and 27 are respectively disposed on the bottom surface of the first type epitaxial layer 2 3 φ and the substrate 21. Wherein, the roughening treatment, as shown in the seventh figure, includes the lower "column step: providing acid-breaking, sulfuric acid, and hydrofluoric acid. Iodine, sulfuric acid and hydrofluoric acid are mixed in a ratio of 2·····1. The mixed liquid is dipped on the surface of the second type epitaxial layer 25, and is etched to complete the roughened surface 2, as shown in the eighth figure, the roughened surface 28 has a plurality of recesses The second type of epitaxial layer 2 5 Table 8 200840087 face recess 2 8 1 . In the specific implementation, as shown in the ninth figure, the single point light source p is also taken as an example, and the display point light source P emits the light rays Pi and P2 to the outside of the quaternary light-emitting diode, other than the outgoing light rays Pi and P2. Light rays, such as the originally emitted total reflections P3, P4', in this illustration, change the angle of incidence via the roughened surface 28 of the second type epitaxial layer 25 such that the angle of incidence is less than the total reflection angle' The light is directly refracted to the outside of the quaternary light-emitting diode. The figure also shows that if a very small portion of the light is emitted to the vertical side of the four-dimensional light-emitting diode, it will form once in the quaternary light-emitting diode or After the above reflection, the same can be directly emitted from the roughened surface 28 to the outside of the quaternary light-emitting diode, so that the effect of light emission can be obviously improved; and the quaternary light-emitting diode of the present invention can change the refractive angle of the light. The light is not directly generated and directly refracted and then emitted to the outside of the quaternary light-emitting diode, and the luminous efficiency of the quaternary light-emitting diode can be significantly improved as a whole. In addition, a λ-distributed Bragg reflection layer 3 1 may be disposed between the first type epitaxial layer 2 3 and the buffer layer 2 2 , and most of the light emitted from the active layer 24 4 may be reflected upward to increase the overall The eigen-out effect of the quaternary light-emitting diode is as shown in the tenth figure, and the window layer 32 is further provided above the second-type epitaxial layer 25, and the window layer 32 can be used as a current distribution and a light source. For the purpose of taking out, forming a roughened surface 2 8 ' on the surface of the window layer 3 2 can also achieve the function of improving the luminous efficiency of the quaternary light-emitting diode. The present invention provides a preferred and feasible quaternary light-emitting diode and a method for manufacturing the same, and submits an application for a patent in accordance with the law; however, the above description and drawings of the above-mentioned 9 200840087 are the present invention. The preferred embodiments are not intended to limit the invention, and the invention is intended to be within the scope of the invention and the scope of the invention. ‘ [Simple description of the diagram] The first diagram is a schematic cross-sectional view of a conventional quaternary light-emitting diode structure. The second figure is a schematic diagram of the conventional light exiting effect. φ The third figure is a schematic diagram of the steps of the manufacturing method of the quaternary light-emitting diode of the present invention. The fourth figure is a schematic view of the first type of epitaxial layer in the present invention. The fifth figure is a schematic view of the second type epitaxial layer in the present invention. The sixth figure is a schematic cross-sectional view of the structure of the quaternary light-emitting diode in the present invention. The seventh figure is a schematic diagram of the steps of the roughening treatment in the present invention. ^ The eighth figure is a schematic structural view of the roughening process in the present invention. The ninth diagram is a schematic diagram of the light exiting effect of the present invention. Φ Tenth is another cross-sectional view of the structure of the quaternary light-emitting diode of the present invention. [Description of main component representative symbols] 1 quaternary light-emitting diode 1 1 - substrate 1 2--buffer layer 13 - first type epitaxial layer 200840087 14 - active layer 14 1 light emission range 15 - Type 2 stupid layer 16 - electrode 1 7--electrode 2 ----- quaternary light-emitting diode 2 1 - substrate 2 2--buffer layer ^ 23--first type stupid layer 2 3 1 a first material layer 2 3 2 - a second material layer 2 3 3 - a third material layer 2 3 4 - a fourth material layer 2 4 - an active layer 25 - a second type stupid layer 2 5 1 a first Material layer 2 5 2 - second material layer 2 6 - one electrode 2 7 - electrode 28 - roughened surface 2 8 1 - recess 31 - distributed Bragg reflection layer 3 2--window layer 11