1334654 九、發明說明： 【發明所屬之技術領域】 本發明是有關於一種固態發光元件（solid-state light- emitting device) ， 特 別是指 一種固態發光元件及其製作方法 〇 【先前技術】 目前影響發光二極體（led)之發光效率值的因素，分別 有内部量子效率（internal quantum efficiency)及外部 (external)量子效率，其中，構成低内部量子效率的主要原 因，則是形成於磊晶膜中的差排量。舉例來說，藍寶石 (sapphire，化學式為Al2〇3)基板與氮化鎵（GaN)系材料兩者 間存在有晶格不匹配度（lattice mismatch)的問題，因此，在 磊晶過程中亦同時地構成了大量的貫穿式差排（threading dislocation) ° 一般而言，於sapphire或碳化碎（SiC)基板上蟲製DI-V 族氮化物（如：GaN...等）磊晶膜時，多半因為sapphire與其 上方蟲晶膜之間的晶格常數差異（lattice constant difference ，簡稱A a)過大，及兩者間的原子耦合（atomic coupling)相 當地微弱等原因，因此，在sapphire基板上成長蟲晶膜期 間，皿-V族氮化物的晶體方位（crystal orientation)無法正確 地向上延續，並使得皿-V族氮化物中存在有起伏的晶體方 位[即，所謂的馬賽克晶體（mosaic crystal)];其中，晶體方 位圍繞著垂直於基板表面的主轴之轉動方向而起伏變化的 扭轉式（twist)馬賽克晶體，以及晶體方位自一垂直方向的軸 5 (wet etching)施予蝕刻處理，進而於第—層磊晶膜幻的表 面形成複數深度約200 nm〜50〇 nm之間的非等深凹槽231 。藉該等非等深凹槽231以降低形成於第―層蟲晶膜^上 之第二層磊晶膜23内的差排量。 依此類推地，於完成第二層磊晶膜23之後，亦對第二 層磊晶膜23的一表面施予蝕刻處理以於第二層磊晶瞑u 上形成複數非等深凹槽231，藉以進一步地降低形成於第二 層磊晶膜23上之第三層磊晶膜23的差排量。因此，當磊 晶膜23的層數越多，最上方的磊晶膜23内之差排量越低 。該磊晶基板2雖然可解決差排問題，但其所形成的非等 深凹槽231對該等磊晶膜23之差排產生彎折的貢獻度亦有 限，此外，諸多蝕刻及磊晶等繁複的製程，亦不符製造成 本。 參閱圖3，US 6,504，183揭示一種氮化物半導體之磊晶 成長。US 6,504，183主要是於一藍寶石基板31上形成一高 度約介於1 nm〜10 nm之間的多重核種（muhiple nUCleUSeS)321、322。進一步地，依序於該多重核種321、 322上形成一差排抑制層33及一形成於該差排抑制層33的 磊晶層34。該多重核種321、322主要是分別由不同材質所 構成。藉由不同材質之核種的晶格常數及該多重核種32 i、 322與藍寶石基板31間的高度差以調整差排35的形成速度 及方向’並抑制因晶格常數差所致的應力。差排35則是被 限制地沿著該多重核種321、322的側邊成長並產生彎折， 因此’降低延伸至該磊晶層34中的差排35量。 US 6,504’183所揭示的内容雖可降低磊晶層34内的差 排35量’但由於該多重核種321、322與藍寶石基板η間 的度差異變化量不足’因此，差排量過高的問題仍具改 善的空間。 參閱圖4 ’ US 6,936,851揭示一種半導體發光裝置之製 作方法。其主要是利用濕式蝕刻法於一基板41的一表面施 予濕式姓刻以於該基板41形成複數由數微型晶面々bo- facet) 所構成的溝槽 。進一步地， 依序於該基板 41 上形成一 傾斜層42及一上層區43。該基板41的溝槽（即，微型晶面） 長:供利於優先成核的位置，因此，該傾斜層42主要是自相 鄰微型晶面的接合處顯露出來並於該等溝槽處結合。另， 該上層區43於成長過程中的傾斜成長（inciined gr〇wth)已趨 於緩慢，因此，該上層區43的一表面已呈現平坦化的狀態 〇 於US 6,936,851所揭示的内容中’其差排主要是朝向 /冓槽的中心並向上傳播，其中，呈反向延伸之相近的差排 相遇後合併且朝上延伸。雖然US 6,936,851所揭示的内容 可減少蠢晶膜内的差排量，但此等微型晶面於表面的變化 量仍嫌不足，因此，對於降低磊晶膜内的差排量之貢獻度 亦有限。 參閱圖5，OS.7,033,854揭露一種於藍寶石基板上對 瓜-V族氮化物結晶化（crystallizing)的方法。其主要是於一 C面藍寶石基板51上形成複數深度大於1〇 nm的等深凹槽 511，並於該C面藍寶石基板51上磊製一磊晶膜52。該磊 1334654 晶膜52具有複數分別填置於該等等深凹槽5ιι内的 XN晶體521、一覆蓋該等AlxGa] χΝ晶體52丨及c面藍寶2’ 基板51的緩衝層522及一霜筌兮绘; 汉復盍該級衝層522的無摻雜 (undoped)GaN 層。 • ♦ US 7,033,854主要是利㈣等等深凹槽511以增加該c 面藍寶石基板（即，Al2〇3)51與該磊晶膜52兩者間原子交互 作用的接觸面積，進而使得該c面藍寶石基板51中的μ φ 原子可因表面積增加而提昇其向上擴散的機率，並使得上 方之AlxGai_xN晶體521是含A1量較高的晶體；另，由於 AlxGai_xN/Sapphire間的晶格常數差（△ a)是明顯地小於 GaN/sapphire間的晶格常數差，因此，在晶格不匹配度降低 的情況下，該等AlxGai.xN晶體521之馬賽克晶體含量較低 且晶體方位較為均勻化；又，該c面藍寶石基板51上方的 晶體方位，可受到構成該等等深凹槽511之複數傾斜表面所 作用的杈向約束力（lateral constrain force)所限制，因此，藉 • 該等等深凹槽511以控制晶體方位，進而降低產生馬赛克晶 體的機率；此外，於完成該緩衝層522之後，對該緩衝層 522連續升溫並施予退火處理，且利用最終的退火溫度於該 緩衝層522上形成該無摻雜GaN層523，藉由此種分段成 長（interruption of growth)而使得該緩衝層522及該無摻雜1334654 IX. Description of the Invention: [Technical Field] The present invention relates to a solid-state light-emitting device, and more particularly to a solid-state light-emitting device and a method of fabricating the same. [Prior Art] Current influence The luminous efficiency values of the light-emitting diodes have internal quantum efficiency and external quantum efficiency, respectively. Among them, the main reason for the low internal quantum efficiency is formed on the epitaxial film. The difference in displacement. For example, there is a problem of lattice mismatch between a sapphire (Al 2 〇 3) substrate and a gallium nitride (GaN)-based material, and therefore, in the epitaxial process, The ground constitutes a large number of threading dislocations. In general, when a DI-V nitride (such as GaN...) is epitaxially filmed on a sapphire or carbonized (SiC) substrate, Mostly, because the lattice constant difference (A a) between sapphire and the above-mentioned insect film is too large, and the atomic coupling between them is rather weak, it grows on the sapphire substrate. During the crystal film, the crystal orientation of the dish-V nitride does not continue upwards correctly, and there is an undulating crystal orientation in the dish-V nitride [ie, so-called mosaic crystal (mosaic crystal) Wherein, the crystal orientation is around a twist mosaic crystal that varies in a direction perpendicular to the direction of rotation of the major axis of the substrate surface, and the crystal orientation is from a vertical axis 5 (w) Et etching is performed to form a non-iso-depth groove 231 having a complex depth of about 200 nm to 50 〇 nm on the surface of the first layer epitaxial film. The non-equivalent grooves 231 are used to reduce the difference in displacement in the second epitaxial film 23 formed on the first layer of the film. And the like, after the second epitaxial film 23 is completed, a surface of the second epitaxial film 23 is also subjected to an etching treatment to form a plurality of non-isocenter grooves 231 on the second epitaxial layer 231u. Thereby, the difference displacement of the third epitaxial film 23 formed on the second epitaxial film 23 is further reduced. Therefore, as the number of layers of the epitaxial film 23 is increased, the difference in the displacement amount in the uppermost epitaxial film 23 is lower. Although the epitaxial substrate 2 can solve the problem of poor displacement, the non-isocenter groove 231 formed by the epitaxial substrate 231 has a limited contribution to the difference between the epitaxial films 23, and many etching and epitaxing. The complicated process does not match the manufacturing cost. Referring to Figure 3, US 6,504,183 discloses epitaxial growth of a nitride semiconductor. US 6,504,183 mainly forms a nucleus (muhiple nUCleUSeS) 321, 322 having a height of between about 1 nm and 10 nm on a sapphire substrate 31. Further, a difference suppression layer 33 and an epitaxial layer 34 formed on the difference suppression layer 33 are formed on the multiplexed species 321 and 322 in sequence. The multiple nucleus species 321, 322 are mainly composed of different materials. The lattice constant of the nucleus of the different materials and the height difference between the multiplexed species 32 i and 322 and the sapphire substrate 31 adjust the formation speed and direction of the difference row 35 and suppress the stress due to the difference in lattice constant. The row 35 is constrained to grow along the sides of the multiple core species 321, 322 and bend, thereby reducing the amount of the difference row 35 extending into the epitaxial layer 34. The content disclosed in US 6,504'183 can reduce the amount of difference 35 in the epitaxial layer 34, but the amount of change in the difference between the multiple cores 321, 322 and the sapphire substrate η is insufficient. Therefore, the difference in displacement is too high. The problem still has room for improvement. Referring to Figure 4'' US 6,936,851, a method of fabricating a semiconductor light emitting device is disclosed. It mainly uses a wet etching method to apply a wet pattern to a surface of a substrate 41 to form a plurality of grooves formed by the plurality of micro-facets 々bo-facet. Further, an inclined layer 42 and an upper layer region 43 are formed on the substrate 41 in sequence. The groove (i.e., the micro-crystal face) of the substrate 41 is long: a position for preferential nucleation. Therefore, the inclined layer 42 is mainly exposed from the joint of the adjacent micro-crystal faces and bonded at the grooves. . In addition, the ingrined gr〇wth of the upper layer region 43 has become slower during growth, and therefore, a surface of the upper layer region 43 has been flattened, as disclosed in US 6,936,851. The difference row is mainly directed toward the center of the gutter and propagates upward, wherein the adjacent rows which are oppositely extended meet and merge and extend upward. Although the disclosure disclosed in US 6,936,851 can reduce the difference in displacement in the amorphous film, the amount of change of the micro-crystal faces on the surface is still insufficient, and therefore, the contribution to the reduction of the differential displacement in the epitaxial film is limited. . Referring to Figure 5, a method of crystallizing a melon-V nitride on a sapphire substrate is disclosed in OS. 7,033,854. The method further comprises forming a plurality of equal-depth grooves 511 having a depth greater than 1 〇 nm on a C-plane sapphire substrate 51, and depositing an epitaxial film 52 on the C-plane sapphire substrate 51. The crystal film 52 has a plurality of XN crystals 521 respectively filled in the deep grooves 5 ι, a buffer layer 522 covering the AlxGa χΝ crystal 52 丨 and the c sapphire 2 ′ substrate 51, and a buffer layer 522 Frost-painted; Han Fu's undoped GaN layer of the layer 522. • ♦ US 7,033, 854 is mainly a deep groove 511 such as ( (4) to increase the contact area of the atomic interaction between the c-plane sapphire substrate (ie, Al 2 〇 3) 51 and the epitaxial film 52, thereby making the c-plane The μ φ atom in the sapphire substrate 51 can increase the probability of upward diffusion due to an increase in surface area, and the upper AlxGai_xN crystal 521 is a crystal containing a higher amount of A1; and, because of the difference in lattice constant between AlxGai_xN/Sapphire (Δ) a) is significantly smaller than the lattice constant difference between GaN/sapphire, therefore, in the case of a decrease in lattice mismatch, the AlxGai.xN crystal 521 has a lower mosaic crystal content and a more uniform crystal orientation; The crystal orientation above the c-plane sapphire substrate 51 may be limited by the lateral constrain force acting on the plurality of inclined surfaces constituting the deep grooves 511, and therefore, The groove 511 controls the crystal orientation, thereby reducing the probability of generating the mosaic crystal; further, after the buffer layer 522 is completed, the buffer layer 522 is continuously heated and subjected to annealing treatment, and the final use is utilized. Annealing temperature is formed on the buffer layer 522 on the undoped GaN layer 523, with such segmented into long (interruption of growth) such that the buffer layer 522 and the undoped
GaN層523的晶體方位更為一致。 經前述幾篇先前技術的說明可知，目前大致上是使用 凹凸化基板的技術手段以解決磊晶膜中差排量過高的問題 。然而’此等凹凸化表面所形成的等深凹槽多呈規則性排 9 1334654 歹！因此’單位面積内所產生的表面起伏之變化性並不顯 著，所能減少的差排量亦有限。即便是呈不規則性排列的 #等冰凹槽所構成的凹凸化表面，其表面起伏的變化性亦 ·_ $夠月帛31此’磊晶膜中之差排量過高的問s，仍有許 多改善的空間。 【發明内容】 因此，本發明之目的，即在提供一種固態發光元件。 # 本發明之另一目的，即在提供一種固態發光元件的製 作方法。 於是，本發明低固態發光元件，包含：一具有一外輪 廓面的基材，及一覆蓋該基材之外輪廓面的半導體化合物 磊晶膜。該外輪廓面具有複數相間隔地向一實質上垂直於 “土材的第一方向凸伸的突出區。每兩相鄰的突出區共同 定義出一向一相反於該第一方向的第二方向凹陷的凹穴區 。該基材之外輪廓面的部分突出區分別具有複數相間隔地 • 向該第—方向凸伸而出的峰部。每兩相鄰的峰部共同定義 出一向該第二方向凹陷的谷部。 ·另，本發明固態發光元件的製作方法，包含以下步驟 U)於一基材上形成一預定成形膜； (b) 對該預定成形膜施予粗化（r〇ughen)處理以使該預定 成形膜形成一粗化表面； (c) 對該粗化表面施予蝕刻處理以移除該預定成形膜並 使該基材根據該粗化表面形成一外輪廓面；及 10 1334654 【主要元件符號說明】The crystal orientation of the GaN layer 523 is more uniform. As can be seen from the description of the prior art, it is generally a technical means of using a embossed substrate to solve the problem of excessively high displacement in the epitaxial film. However, the isobath grooves formed by these embossed surfaces are mostly regular rows 9 1334654 歹! Therefore, the variability of the surface undulations generated per unit area is not significant, and the amount of difference that can be reduced is also limited. Even if the irregular surface formed by the irregularities such as the ice groove is irregular, the surface undulation is also _ _ _ _ _ _ _ _ 31 this 'deposition of the difference in the epitaxial film is too high s, There is still much room for improvement. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a solid state light emitting device. Another object of the present invention is to provide a method of fabricating a solid state light emitting device. Accordingly, the low solid state light emitting device of the present invention comprises: a substrate having an outer profile; and a semiconductor compound epitaxial film covering the outer contour of the substrate. The outer contour surface has a plurality of spaced apart regions extending substantially perpendicular to the first direction of the soil material. Each two adjacent protruding regions collectively define a first direction opposite to the first direction. a recessed recessed portion. The partial protruding regions of the outer contour surface of the substrate respectively have a plurality of spaced apart peaks protruding from the first direction. Each two adjacent peaks define a common Further, the method for fabricating the solid-state light-emitting device of the present invention comprises the steps of: U) forming a predetermined formed film on a substrate; (b) applying a roughening to the predetermined formed film (r〇) Processing to form the roughened surface to form the roughened surface; (c) applying an etching treatment to the roughened surface to remove the predetermined formed film and forming an outer contoured surface of the substrate according to the roughened surface; And 10 1334654 [Description of main component symbols]
6 ....... •…基材 71 ··.·· •…成核層 65…… …·基材 71，···. •…成核層 6”…… •…基材 71”… •…成核層 61…… •…外輪廓面 72••… . 猫日日層 61，···. •…外輪廓面 72’·... • 從Β曰層 61”… •…外輪廓面 72”… • 猫日日層 611… •…突出區 721 ··· •…第一導電型半導體 612… •…凹穴區 722… …·多重量子井 613… •…峰部 723 ·· …·第二導電型半導體 614… •…谷部 8…… …·接觸電極 615… •…峰部 9…… …·預定成形膜 616… •…谷部 91 ··... —粗化表面 7…… 半導體化合物胡日日膜 92··.·. •…喷嘴 V ···.. •…半導體化合物日日膜 Υι••… —第 方向 7”…… •…半導體化合物磊晶膜 γ2··.·· •…第二方向 226 ....... •...Substrate 71 ·······...Nuclear layer 65...··Substrate 71,···.•...Nuclear layer 6”... •...Substrate 71 ”... •...Nuclear layer 61... •...Outer contour surface 72••... . Cat day layer 61,···. •...Outer contour surface 72'·... • From Β曰 layer 61”... • ...outer contour surface 72"... • Cat day layer 611... •... protruding area 721 ····...first conductive type semiconductor 612...•...cavity area 722...·multiple quantum well 613... •...peak 723 ····Second conductive semiconductor 614...•...Valley 8...Contact electrode 615...•...Peak 9.........Predetermined formed film 616...•...Valley 91 ··...—Coarse Surface 7... Semiconductor compound Hu Riji film 92····. •...Nozzle V ···..•...Semiconductor compound Day film Υι••... —1st direction 7”... •...Semiconductor compound epitaxial Membrane γ2··.·· •...second direction 22