201225331 六、發明說明： 【發明所屬之技術領域】 本發明係有關一種類光晶結構之製造方法，尤指一種應 用於發光元件中，可提高外部光取出效率之製造方法。 【先前技術】 固態發光元件，例如高亮度發光二極體（High _ Brightness Light Emitting diode ; BH-LED)或雷射二極體 參（Laser Diode; LD) ’具有低耗電量、低發熱量、操作壽命長、 耐撞擊、體積小、反應速度快、以及可發出穩定波長的色光 等良好光電特性，因此常應用於家電、儀表之指示燈、光電 產品之應用。隨著光電科技的進步，固態發光元件在提升發 光效率、使用壽命以及亮度等方面已有長足的進步，在不久 的將來將成為未來發光元件的主流。 以發光二極體為例，其基本的結構係包括基板、形成於 基板的緩衝層、形成於緩衝層上的N型半導體層、覆蓋N髮 鲁半導體層的主動層、形成於主動層上方的p型半導體層，以 及分別與兩半導體層電性連結的接觸電極層。 發光二極體的發光效能係取決於主動層或電激發光層 (Electro-luminescence Layer)之内部量子效率（Internal Quantum Efficiency)與外部光取出效率（Extraction Efficiency)兩大主要因素。隨著各式磊晶技術的進步，目前 内在發光效率可達80%以上，但是發光二極體的光取出效率 卻仍然偏低。例如氮化鎵系材料的折射係數約為2.5，而外 界空氣的折射係數則為1 ’由於全反射的原因，造成在氮化 201225331 鎵系材料和空氣之界面上僅約有1(M2%的光被取出。 至於改善外部光取出效率方面，習知技術如台灣公開號 第200832740號「發光二極體結構及其製造方法」中，係採 用微影、蝕刻製程以及陽極處理技術（或電子束轟擊）在基板 表面製造一層具有（週期性）奈米級晶格係數之二維光晶結 構，此光晶結構可以有效的改善磊晶品質，增加内部量子發 光效率。 上述習知技術中該光晶結構之成型步驟如下： 1、 上光阻於基板表面； 2、 經過曝光（微影製程）形成一具有曝光區與非曝光區之 光阻層； 3、 顯影製程，將曝光區之光阻層移除； 4、 硬烤（hard bake)製程以利於後續製程； 5、 利用濕式蝕刻（或乾蝕刻、拋光、電子束、離子束等 技術）將基板表面蝕刻形成一具有週期性孔洞間距之基板； 6、 沉積一緩衝層，其可作為後續製成週期性孔洞所必 之緩衝層； ^隨後，利用锻膜沉積技術（例如蒸鍍、濺鍍、電漿式 化子氣相％積、化學氣相沉積、物理氣相沉積、熱浸鍵） 一金屬薄膜於基板之上，並填滿孔洞； _然後，再利用陽極處理（an〇dizati〇n)技術在基板與 孔同表面形成週期性奈米級多孔性氧化金屬薄膜圖案，以構 成類光晶結構。 藉由上述步驟雖可製造出類光晶結構，用以改善磊晶品 質增加内部量子發光效率，並解決基板與蟲晶層之間的光 201225331 全反射之問題以及減少沿著界面產生的側向漏光情形，可有 效地提昇了發光二極體的外部取光效率；惟，上述技術製程 複雜耗時且成本高昂。故極需要一種簡易、快速且節省成本 且能在發光元件内形成類光晶結構的方法。 【發明内容】 有鑑於此，本發明即在提供一種類光晶結構之製造方 法，提供一種應用於發光元件中，製程簡便並可提高外部光 •取出效率之製造方法，為其主要目的者。 為達上述目的，本發明之製造方法係於一基板上利用分 子束磊晶形成有複數垂直配置且週期排列之奈米柱，各奈米 柱之高度係大於0. Ιμιη，再於各奈米柱表面利用化學氣相沉積 形成一氮化物半導體緩衝層，而該氮化物半導體緩衝層與各 奈米柱間則形成有氣隙，並於該氮化物半導體緩衝層表面形 成發光元件，藉由各氣隙形成類光晶結構以抑制發光元件之 全反射效應，提高外部光取出效率。 【實施方式】 本發明之特點，可參閱本案圖式及實施例之詳細說明而 獲得清楚地瞭解。 本發明主要提供一種類光晶結構之製造方法，如第一圖 所示，其至少包含有下列步驟： 步驟A、提供一基板11，如第二圖（Α)所示，該基板11 可以為藍寶石、氧化鋅、氮化鎵、碳化矽、石英、矽、鋁酸 鋰或尖晶石材質； 201225331 步驟B、進行分子束蟲晶（molecular beam epitaxy ; MBE) ’係可於700~800°C環境中進行，使該基板正面hi形 成有複數垂直配置且週期排列之奈米柱12，如第二圖（B)所 示’該奈米柱12可以為III-V族（三五族）半導體材料，例如 氮化鎵材料，各奈米柱12之高度係大於〇· ΐμιη，而為使各奈 米柱12與基板11介面更相容’該基板正面111與各奈米柱 12間可先進一步設有緩衝膜層14，其中該緩衝膜層14可以 為氮化鋁材料； 步驟C、進行化學氣相沉積【可為有機金屬化學氣相沉 〇 積（metal-organic chemical vapor deposition ; M0CVD)】， 於各奈米柱12表面利用化學氣相沉積進行橫向蟲晶形成一 氮化物半導體緩衝層13,如第二圖（C)所示，該氮化物半導 體緩衝層13可以為m-V族（三五族）半導體材料，例如氮化 鎵材料，其成長溫度可為10〇(Ml〇〇〇C，而成長時間為1〇〜2〇 分鐘，進行橫向磊晶時，請同時參閱第三圖所示，因各奈米 桂12之間的間隙121因面積甚小，在橫向磊晶的過程中，往 往無法使蠢晶達到奈米柱12之間的間隙121表面，且以奈米❶ 柱12作為同質磊晶的種子（seed)，可使該氮化物半導體緩衝 層13接續生長於各奈綠12上，且有少許橫向沉積在間隙 121邊緣，而該氮化物半導體緩衝層13與各奈米 形成有氣隙122 ^ 步驟D、該氮化物半導體緩衝層13表面形成發光元件如 第四圖所示，其設有一未掺雜半導體層15、一第一型掺雜半 導體層16、一發光層17、一第二型掺雜半導體層18以及第一、 第二電極191、192，係分別設置於該第一、第二型掺雜半導 201225331 體層16、18之上表面。 本發明中藉由各氣隙形成類光晶結構，可以破壞發光元 件發出光線被全反射的光以抑制全反射效應，可允許，使 原來被内部全反射損失之部分光線發射出來，提高發光元件 外部光取出效率。 本發明中，係以光輸出-電流-電壓（Liv)系統，來測量 NP-LED(本發明所成型具有類光晶結構之發光元件）與 C-LED( —般發光元件）之發光效率，其結果如第五圖所示。由 •第五圖中可明顯看出，該NP-LED的發光效率均優於C_LED，例 如在輸入電流20 mA時，該NP-LED的發光效率較C-LED高出 55%。顯示類光晶結構有助於提昇發光元件的發光效率。 再利用有限差分時域法（FDTD)測試NP-LED與C-LED之發 光效率，其結果如第六圖所示。由第六圖中可明顯看出，該 NP-LED的發光效率均優於c-LED ,該NP-LED的發光效率較 C-LED高出48. 4%。亦顯示類光晶結構有助於提昇發光元件的 發光效率。 φ 當然’亦可先於該步驟C之後先進行降溫製程，如第七圖 所不’會在環境溫度下降約至室溫時，因基板11與各奈米柱 12異質材料熱膨脹係數的差異，於界面間強度最弱的地方自 然分離’即例如在各奈米柱12處產生斷裂，令該氮化物半導 體緩衝層13自該基板11表面分離。 如上所述’本發明提供一較佳可行類光晶結構之製造方 法’麦依法提呈發明專利之申請；本發明之技術内容及技術 特點巳揭示如上’然而熟悉本項技術之人士仍可能基於本發 明之揭示而作各種不背離本案發明精神之替換及修飾。因 201225331 此，本發明之保護範圍應不限於實施例所揭示者，而應包括 各種不背離本發明之替換及修飾，並為以下之申請專利範圍 所涵蓋。 【圖式簡單說明】 第一圖係為本發明中類光晶結構之製造流程方塊圖。 第二圖（AMC)係為本發明中類光晶結構之製造流程示 意圖。 第三圖係為本發明中進行橫向磊晶之結構示意圖。 ® 第四圖係為本發明中具有類光晶結構之發光元件之結構 立體圖。 第五圖係為本發明中光輸出-電流-電壓（LIV)系統之測 試結果圖。 第六圖係為本發明中有限差分時域法（FDTD)之測試結果 圖。 第七圖係為本發明中進行基板剝離之結構示意圖。 【主要元件符號說明】 基板11 未掺雜半導體層15 正面111 第一型掺雜半導體層16 奈米柱12 發光層17 間隙121 第二型掺雜半導體層18 氣隙122 第一電極191 氮化物半導體緩衝層13 第二電極192 緩衝膜層14201225331 VI. Description of the Invention: [Technical Field] The present invention relates to a method for producing a crystal-like crystal structure, and more particularly to a manufacturing method for use in a light-emitting element to improve external light extraction efficiency. [Prior Art] Solid-state light-emitting elements such as High _ Brightness Light Emitting diodes (BH-LEDs) or Laser Diodes (LDs) have low power consumption and low heat generation. It has long operating life, impact resistance, small volume, fast reaction speed, and good photoelectric characteristics such as color light with stable wavelength. Therefore, it is often used in the application of indicator lights and optoelectronic products for home appliances and meters. With the advancement of optoelectronic technology, solid-state light-emitting components have made great progress in improving luminous efficiency, service life, and brightness, and will become the mainstream of future light-emitting components in the near future. Taking a light-emitting diode as an example, the basic structure includes a substrate, a buffer layer formed on the substrate, an N-type semiconductor layer formed on the buffer layer, an active layer covering the N-ray semiconductor layer, and a top layer formed on the active layer. a p-type semiconductor layer and a contact electrode layer electrically connected to the two semiconductor layers, respectively. The luminous efficacy of the light-emitting diode depends on the two main factors of the internal quantum efficiency (Internal Quantum Efficiency) and the external light extraction efficiency (Extraction Efficiency) of the active layer or the electro-luminescence layer. With the advancement of various epitaxial technologies, the intrinsic luminous efficiency can reach over 80%, but the light extraction efficiency of the LED is still low. For example, a gallium nitride-based material has a refractive index of about 2.5, and the outside air has a refractive index of 1 ' due to total reflection, resulting in only about 1 (M2%) at the interface of the nitrided 201225331 gallium-based material and air. Light is taken out. As for improving the efficiency of external light extraction, conventional techniques such as Taiwan Publication No. 200832740 "Light Emitting Diode Structure and Manufacturing Method" use lithography, etching processes, and anodizing techniques (or electron beams). Bombardment) A two-dimensional photocrystal structure having a (periodic) nano-scale lattice coefficient is formed on the surface of the substrate, and the photo-crystal structure can effectively improve the epitaxial quality and increase the internal quantum luminescence efficiency. The forming process of the crystal structure is as follows: 1. The upper photoresist is on the surface of the substrate; 2. The photoresist layer having the exposed area and the non-exposed area is formed by exposure (lithography process); 3. The developing process, the photoresist of the exposed area Layer removal; 4, hard bake process to facilitate subsequent processes; 5, using wet etching (or dry etching, polishing, electron beam, ion beam, etc.) to substrate Surface etching to form a substrate having a periodic hole pitch; 6. depositing a buffer layer, which can serve as a buffer layer for subsequent periodic holes; ^ Subsequently, using a forged film deposition technique (eg, evaporation, sputtering, Plasma gas phase % product, chemical vapor deposition, physical vapor deposition, hot dip bond) a metal film on the substrate and fill the hole; _, then use the anode treatment (an〇dizati〇n The technique forms a periodic nano-scale porous oxidized metal thin film pattern on the same surface of the substrate and the hole to form a light-like crystal structure. The above-mentioned steps can produce a light-like crystal structure for improving the epitaxial quality and increasing the internal quantum. Luminous efficiency, and solve the problem of total reflection of light 201225331 between the substrate and the insect layer and reduce the lateral light leakage along the interface, which can effectively improve the external light extraction efficiency of the LED; however, the above technology The process is complicated, time-consuming and costly. Therefore, there is a great need for a simple, fast and cost-effective method for forming a light-like crystal structure in a light-emitting element. The present invention provides a method for fabricating a crystal-like crystal structure, and provides a manufacturing method which is applied to a light-emitting element, has a simple process and can improve external light extraction efficiency, and is a main object thereof. To achieve the above object, the present invention The manufacturing method is performed by using a molecular beam epitaxy to form a plurality of vertically arranged and periodically arranged nano columns on a substrate, wherein the height of each nano column is greater than 0. Ιμιη, and then chemical vapor deposition is performed on the surface of each nano column. Forming a nitride semiconductor buffer layer, and forming an air gap between the nitride semiconductor buffer layer and each of the nano columns, forming a light-emitting element on the surface of the nitride semiconductor buffer layer, and forming a light-like crystal structure by each air gap The external light extraction efficiency is improved by suppressing the total reflection effect of the light-emitting element. [Embodiment] The features of the present invention can be clearly understood by referring to the detailed description of the drawings and the embodiments. The present invention mainly provides a method for fabricating a light-like crystal structure, as shown in the first figure, which comprises at least the following steps: Step A, providing a substrate 11, as shown in the second figure (Α), the substrate 11 may be Sapphire, zinc oxide, gallium nitride, tantalum carbide, quartz, tantalum, lithium aluminate or spinel; 201225331 Step B, molecular beam epitaxy (MBE) ' can be 700~800 °C In the environment, the front surface of the substrate is formed with a plurality of vertically arranged and periodically arranged nano-pillars 12, as shown in the second figure (B). The nano-pillars 12 may be III-V (three-five) semiconductors. The material, such as a gallium nitride material, has a height greater than 〇·ΐμιη for each nanocolumn 12, and is more compatible with the interface between the nano-pillars 12 and the substrate 11 'the front surface of the substrate 111 and each of the nano-pillars 12 Further, a buffer film layer 14 is provided, wherein the buffer film layer 14 may be an aluminum nitride material; Step C, performing chemical vapor deposition [may be metal-organic chemical vapor deposition (M0CVD)] 】, on the surface of each nano column 12 Vapor deposition is performed to form a nitride semiconductor buffer layer 13 laterally, and as shown in FIG. 2C, the nitride semiconductor buffer layer 13 may be an mV (three-five) semiconductor material such as a gallium nitride material. The growth temperature can be 10〇(Ml〇〇〇C, which is 1〇~2〇 minutes for a long time. When performing lateral epitaxy, please refer to the third figure at the same time, because of the difference between each nano-gui 12 The gap 121 is small in area, and in the process of lateral epitaxy, it is often impossible to make the stray crystal reach the surface of the gap 121 between the nano-pillars 12, and the nano-column 12 is used as a seed for homogenous epitaxy. The nitride semiconductor buffer layer 13 is successively grown on each of the green layers 12, and a little laterally deposited on the edge of the gap 121, and the nitride semiconductor buffer layer 13 and each of the nanoparticles are formed with an air gap 122 ^ Step D, the nitrogen The light-emitting element is formed on the surface of the buffer layer 13 of the compound semiconductor as shown in FIG. 4, and is provided with an undoped semiconductor layer 15, a first-type doped semiconductor layer 16, a light-emitting layer 17, and a second-type doped semiconductor layer 18. And the first and second electrodes 191 and 192 are respectively provided In the first and second types of doped semiconductor layers 16, 18 on the upper surface of the body layers 16, 18. In the present invention, by forming a light-like crystal structure by each air gap, the light emitted by the light-emitting element to be totally reflected can be destroyed to suppress total reflection. The effect is to allow a part of the light originally lost by the internal total reflection to be emitted, thereby improving the external light extraction efficiency of the light-emitting element. In the present invention, the NP-LED is measured by a light output-current-voltage (Liv) system. The luminous efficiency of the light-emitting element having a light-like crystal structure and the C-LED (general light-emitting element) formed by the invention is as shown in the fifth figure. It can be clearly seen from the fifth figure that the NP-LED has better luminous efficiency than C_LED. For example, when the input current is 20 mA, the NP-LED has a luminous efficiency 55% higher than that of the C-LED. Displaying a light crystal structure helps to improve the luminous efficiency of the light emitting element. The luminescence efficiency of NP-LEDs and C-LEDs was tested by finite difference time domain method (FDTD), and the results are shown in the sixth figure. It is apparent from the sixth figure that the luminous efficiency of the NP-LED is better than that of the c-LED, and the luminous efficiency of the NP-LED is 48. 4% higher than that of the C-LED. It is also shown that the crystal-like structure contributes to the improvement of the luminous efficiency of the light-emitting element. φ Of course, the temperature reduction process may be performed after the step C, as shown in the seventh figure, when the ambient temperature drops to about room temperature, due to the difference in thermal expansion coefficient between the substrate 11 and each nano column 12 heterogeneous material, The separation is naturally performed at the weakest inter-interface strength, that is, for example, a fracture occurs at each of the nano-pillars 12, and the nitride semiconductor buffer layer 13 is separated from the surface of the substrate 11. As described above, the present invention provides a method for manufacturing a photo-crystal structure of a preferred viable crystallographic structure. The technical content and technical features of the present invention are disclosed above. However, those skilled in the art may still be based on The invention is not to be construed as being limited or modified by the spirit of the invention. The scope of the present invention is not limited by the scope of the present invention, and is intended to be included in the following claims. BRIEF DESCRIPTION OF THE DRAWINGS The first figure is a block diagram of the manufacturing process of the optical crystal structure of the present invention. The second diagram (AMC) is a schematic diagram of the manufacturing process of the optical crystal structure of the present invention. The third figure is a schematic view of the structure of lateral epitaxy in the present invention. The fourth figure is a perspective view showing the structure of a light-emitting element having a light-like crystal structure in the present invention. The fifth figure is a test result diagram of the light output-current-voltage (LIV) system of the present invention. The sixth figure is a test result chart of the finite difference time domain method (FDTD) in the present invention. The seventh figure is a schematic structural view of the substrate peeling in the present invention. [Description of main component symbols] Substrate 11 Undoped semiconductor layer 15 Front side 111 First type doped semiconductor layer 16 Nano pillar 12 Light-emitting layer 17 Gap 121 Second-type doped semiconductor layer 18 Air gap 122 First electrode 191 Nitride Semiconductor buffer layer 13 second electrode 192 buffer film layer 14