1276232 玖、發明說明： 【發明所屬之技術領域】 本發明係有關於一種製作發光二極體的方法，尤指一種 具有淨化色彩，並且具有增強光引出效率之發光二極體的製 造方法。 【先前技術】 請參閱第一圖所示，發光二極體内部產生的光只有入射 角小於臨界角的光才有機會離開發光二極體,其餘的光在發 光二極體内部反射或被吸收，導致一般發光二極體的光引出 效率不佳的現象（通常低於ίο%)。為了提昇光引出效率，過去 已有許多不同的方法被提出來討論過。例如： 由M· R. Krames等人於「應用物理論文篇」中，第75 篇，第2365頁（1999)所提出的金字塔型的發光二極體晶片； 由Schnitzer等人於「應用物理論文篇」中，第63篇，第 2174頁（1993)所提出的隨機表面組織；以及 由M. R. Krames等人於美國專利US 5,779,924中所揭 示之規律的界面組織。 所有上述習知方法皆可抑制光線於發光二極體晶片表 面上的反射，或增加發光二極體内部產生光可射出的角度， 但它們對於被發射出來的波長卻不是相當敏感。因此，這無 法將光引出特性準確地與一特定的波長作配合，此外，其亦 1276232 無法過濾、由發光二極體所發射出的光譜。 本發明係藉用具有準確參數的特別六角形繞射晶格來 且可將橫向傳輸的光線轉換成垂直傳輸的 Ά再者，其可過濾由發光二極體所發射出來的光譜。 【發明内容】 因此’本發明的目的在於創作出-具有淨化顏色功能之 繞射晶格的發光二極體。 本毛明的主要目的在於藉由繞射晶格中光擴散的一致 來淨化毛S 一極體所發射出的光線以及提昇其引出效 率。 、糟由繞射晶格的使用可有效地將橫向傳輸的光線轉換 成為垂直傳輸，此外可同時過據由發光二極體所發射出之光 譜。 由繞射晶格所過濾的發光二極體光譜得以淨化由發光 二極體所發射出來的光線顏色。料，發光二極體光譜的過 濾得以將由不同晶圓或晶圓不同部位所製造的發光二極體 晶片之波長的差異性予以降低。 一種形成二維繞射晶格的方法，該繞射晶格具有一自行 組織的氧化鋁非結晶式（amorphous)的薄膜細孔圖樣，係藉 由陽極氧化作用形成於鋁薄膜上，而氧化鋁中之細孔的橫向 間距以及其深度係由施予的電壓、電解液的成份以及氧化 1276232 的時間來進行控制。 【實施方式】 首先，請參閱第二圖，其係為本發明之第一實施例。本實 施例具有一藍寶石（Ah〇3)基板（1)以及_設置於其上之氮化 鎵基的發光二極體結構(2)。 於氮化鎵基的發光二極體結構(2)上，藉由乾平面餘刻 技術來形成二維繞射晶格(3 )。藉由繞射晶格可將橫向傳輸 的光線（4)轉換成垂直行進的光線（5)，因此得以提升光引出 效率。繞射晶格結構係圖示於第四圖中。 繞射晶格的橫向間距^/的方程式可表示為^城其 中m為-正整數m.·)、福一由發光二極體所產生 之光線的波長、/2為氮化鎵的折射率。為了讓具有丨，2, 3···的擴散最有效率，〇階的繞射必需予以壓制。這正好發生 在當形成繞射晶格的六角區域高度為/2==义(2/+1)/^” ^ 2, 3····，及繞射晶格内的凸島和凹溝的總面積是相同的。為 了讓這些面積相等，六角侧邊s可表示為^/2/2。因此，當 發光-極體的H42 μηι’繞射晶袼之w = 1，/=()時，則其參數 為㈣·17 μηι、/^0·085 μηι、㈣〇6㈣。繞射晶格的應用 可有效地將橫向傳輸的光線轉換成為垂直傳輸，此外可同時 過慮由發光二極體所發射出之光譜。 由繞射晶格所過濾的發光二極體光譜得以淨化由發光 1276232 二極體所發射出來的光線顏色。此外，發光二極體光譜的過 濾付以將由不同晶圓或晶圓不同部位所製造的發光二極體 晶片之波長的差異性予以降低。 接著，請參閱第三圖，其係為本發明之第二實施例。本實 施例具有一藍寶石（Al2〇3)基板（1)，另藉由乾平面蝕刻技術 來形成二維繞射晶格（3)於該藍寶石（Al2〇3)基板⑴上。另在 繞射晶格（3)上設置一氮化鎵基的發光二極體結構(2)。 繞射晶格結構係圖示於第五圖中。 藉由繞射晶格可將橫向傳輸的光線(4)轉換成垂直行進 的光線（5)，因此得以提升光引出效率。 繞射晶格的橫向間距J的方程式可表示為^，其 中所為一正整數(所=un··)、乂為一由發光二極體所產生 之光線的波長、/7為氮化鎵的折射率。為了讓具有饥=1，2, 3···的擴散最有效率，〇階的繞射必需予以壓制。這正好發生 在當形成繞射晶格的六角區域高度為；/=〇, u 2, 3···.，及繞射晶格内的凸島和凹溝的總面積是相同的。為 了讓這些面積相等，六角邊s必需符合下列等式。 因此，當發光二極體的Α=〇·5 μπι，繞射晶袼之w=2, /=〇 μηι、尸〇·14 μηι 〇 時，貝1J其參數為3=0.4 μιη、A=〇.l 繞射晶格的應用可有效地將橫向傳輸的光線轉換成為 垂直傳輸，此外可同時過濾由發光二極體所發射出之光譜。 1276232 由繞射晶格所過濾器的發光二極體光譜得以淨化由發 、 光二極體所發射出來的光線顏色。此外，發光二極體光譜的 - 過濾得以將由不同晶圓或晶圓不同部位所製造的發光二極 體晶片之波長的差異性予以降低。 本發明之第三實施例的圖示亦請參閱第二圖。本實施 ： 例具有一藍寶石（Al2〇3)基板（1)以及一設置於其上之氮化鎵 ~ 基的發光二極體結構(2)。 於氮化鎵基的發光二極體結構(2)上，形成二維的Ai2〇3 % 繞射晶格(3)。該Al2〇3繞射晶格(3)係由紹薄膜的陽極氧化 作用來形成。該繞射晶格結構係圖示於第六圖中。 繞射晶格的橫向間距^/的方程式可表示為心所仏，其 中所為-正整數(w= H3·..)、福一由發光二極體所產生 之光線的波長1為氮化鎵的折射率。為了讓具有所=1, 2， 3…的擴散最有效率，〇階的繞射必需予以_。這正好發生 在當形成繞射晶格的圓柱孔深度為,=/1(2/+1)/2”，/為正整 # 數或零而它們的半徑r必需符合下列等式狗"2。 因此，當發光二極體的4=0.5 μιη，繞射晶格之^，㈣ 時，則其參數為心〇.21 μηι m μιη ⑽叫。 繞射晶格的應用可有效地將橫向傳輸的光線轉換成為 垂直傳輸，此外可同時過濾、由發光二極體所發射出之光譜。 由繞射晶格所過濾的發光二極體光譜得以淨化由發光 10 1276232 二極體所發射出來的光線顏色。此外，發光二極體光譜的過 濾得以將由不同晶圓或晶圓不同部位所製造的發光二極體 晶片之波長的差異性予以降低。 本發明之第四實施例的圖示亦請參閱第二圖。本實施 例具有一砷化鎵（GaAs)基板（1)以及一設置於其上之磷化鋁 銦鎵(AlGalnP)為基礎的發光二極體結構(2)。 於磷化鋁銦鎵基的發光二極體結構（2)上，形成二維的 Al2〇3繞射晶格（3)。該Al2〇3繞射晶格（3)係由鋁薄膜的陽極 氧化作用來形成。 該繞射晶格結構係圖不於第六圖中。 繞射晶格的橫向間距d的方程式可表示為ΑΛζ，其 中m為一正整數(m= 1，2,3.·.)、A為一由發光二極體所產生 之光線的波長、π為AlGalnP的折射率。為了讓具有m=l， 2, 3...的擴散最有效率，0階的繞射必需予以壓制。這正好發 生在當形成繞射晶格的圓柱孔深度可表示為/2=4(2/+1)/2% /為正整數或零。而它們的半徑r必需符合下列等式 γ=ά(七Ι4π)ιη ° 因此，當發光二極體的Α=0·6 μιη，繞射晶格之m = / = 0 日寺，貝1J 其參數為 3=〇·18 μηι、/2=0.09 μηι、r = 0.066 μιη。 繞射晶格的應用可將橫向傳輸的光線轉換成為垂直傳 輸，此外可同時過濾由發光二極體所發射出之光譜。 11 1276232 由繞射s曰格所過滤的發光二極體光譜得以淨化由發光 二極體所發射出來的光線顏色。此外，發光二極體光譜的過 慮知以將由不同晶圓或晶圓不同部位所製造的發光二極體 晶片之波長的差異性予以降低。 綜上所述，本發明所揭示之技術手段，確具「新穎性」、 「進步性」及「可供產業利用」等發明專利要件，祈請鈞 局惠賜專利，以勵發明，無任德感。 惟，上述所揭露之圖式、說明，僅騎發明之較佳實施例， 大凡熟悉此項技藝人士，依本賴神料所作之修飾或等效 變化，仍應包括本案申請專利範圍内。 12 I276232 【圖式簡單說明】 太第一圖係為一不具有繞射晶格的習知發光二極體之示 忍圖，其中入射角大於臨界角的光線皆被捕捉於晶片内； 一第二圖係為在頂面上具有繞射晶格之發光二極體晶片 之不思圖，其中，繞射晶袼將橫向傳輸的光線轉換成為垂直 傳輪的光線；BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of fabricating a light-emitting diode, and more particularly to a method of fabricating a light-emitting diode having a clean color and having enhanced light extraction efficiency. [Prior Art] As shown in the first figure, the light generated inside the light-emitting diode has only a chance that the light having an incident angle smaller than the critical angle has a chance to leave the light-emitting diode, and the remaining light is reflected or absorbed inside the light-emitting diode. , resulting in poor light extraction efficiency of the general light-emitting diode (usually lower than ίο%). In order to improve light extraction efficiency, many different methods have been proposed in the past. For example: Pyramid-type light-emitting diode wafers proposed by M. R. Krames et al., Applied Physics Papers, 75, p. 2365 (1999); by Applied Papers by Schnitzer et al. The random surface structure proposed in Section 63, page 2174 (1993); and the regular interfacial organization disclosed in U.S. Patent No. 5,779,924 to the name of U.S. Patent No. 5,779,924. All of the above conventional methods can suppress the reflection of light on the surface of the light-emitting diode wafer or increase the angle at which light can be emitted inside the light-emitting diode, but they are not quite sensitive to the emitted wavelength. Therefore, this does not allow the light extraction characteristics to be accurately matched to a specific wavelength. Further, it is also 1276232 which cannot filter the spectrum emitted by the light-emitting diode. The present invention utilizes a special hexagonal diffractive lattice with accurate parameters and converts laterally transmitted light into a vertically transmitted ridge which filters the spectrum emitted by the illuminating diode. SUMMARY OF THE INVENTION Therefore, the object of the present invention is to create a light-emitting diode having a diffraction lattice which purifies a color function. The main purpose of Ben Maoming is to purify the light emitted by the hair S and improve the extraction efficiency by uniformity of light diffusion in the diffraction lattice. The use of the diffraction lattice can effectively convert the laterally transmitted light into a vertical transmission, and at the same time pass the spectrum emitted by the light-emitting diode. The luminescent diode spectrum filtered by the diffractive crystal lattice purifies the color of the light emitted by the illuminating diode. The filtering of the luminescence diode spectrum reduces the difference in wavelength of the luminescent diode wafers fabricated from different wafers or different parts of the wafer. A method of forming a two-dimensional diffraction lattice having a self-organized alumina amorphous film pore pattern formed on an aluminum film by anodization, and alumina The lateral spacing of the pores and their depth are controlled by the applied voltage, the composition of the electrolyte, and the time of oxidation of 1276232. [Embodiment] First, please refer to the second figure, which is the first embodiment of the present invention. This embodiment has a sapphire (Ah〇3) substrate (1) and a gallium nitride-based light-emitting diode structure (2) disposed thereon. On the gallium nitride-based light-emitting diode structure (2), a two-dimensional diffraction lattice (3) is formed by a dry plane residual technique. By diffracting the crystal lattice, the laterally transmitted light (4) can be converted into the vertically traveling light (5), thereby improving the light extraction efficiency. The diffraction lattice structure is shown in the fourth figure. The equation of the lateral spacing of the diffractive lattice ^/ can be expressed as ^ where m is a positive integer m. ·), the wavelength of the light produced by the light-emitting diode, and the refractive index of GaN . In order to make the diffusion with 丨, 2, 3··· the most efficient, the diffraction of the 〇 order must be suppressed. This happens precisely when the height of the hexagonal region where the diffraction lattice is formed is /2===(2/+1)/^” ^ 2, 3····, and the convex islands and grooves in the diffraction lattice The total area is the same. To make these areas equal, the hexagonal side s can be expressed as ^/2/2. Therefore, when the light-polar body H42 μηι' is diffracted, w = 1, /=() When the parameters are (4)·17 μηι, /^0·085 μηι, (4)〇6 (4), the application of the diffraction lattice can effectively convert the laterally transmitted light into vertical transmission, and at the same time, the light-emitting diode can be simultaneously considered. The emitted spectrum. The luminescence spectrum filtered by the diffraction lattice is used to purify the color of the light emitted by the illuminating 1272232 diode. In addition, the filtering of the luminescent diode spectrum will be performed by different wafers or The difference in wavelength of the light-emitting diode wafer manufactured at different parts of the wafer is reduced. Next, please refer to the third figure, which is a second embodiment of the present invention. This embodiment has a sapphire (Al2〇3). a substrate (1), which is formed by a dry planar etching technique to form a two-dimensional diffraction lattice (3) to the sapphire (Al) 2〇3) on the substrate (1). A gallium nitride-based light-emitting diode structure (2) is further disposed on the diffraction lattice (3). The diffraction lattice structure is shown in the fifth figure. The diffraction lattice can convert the laterally transmitted light (4) into the vertically traveling light (5), thereby improving the light extraction efficiency. The equation of the lateral spacing J of the diffraction lattice can be expressed as ^, where a positive integer (==··), 乂 is the wavelength of the light generated by the light-emitting diode, and /7 is the refractive index of gallium nitride. In order to let the diffusion with hunger=1, 2, 3··· Efficiency, the diffraction of the 〇 order must be suppressed. This happens precisely when the height of the hexagonal region where the diffraction lattice is formed is; /=〇, u 2, 3···., and the convex islands in the diffraction lattice The total area of the grooves is the same. In order to make these areas equal, the hexagonal edge s must conform to the following equation. Therefore, when the light-emitting diode is Α=〇·5 μπι, the diffraction crystal is w=2, /= 〇μηι, 〇 〇 · 14 μηι 〇, Bay 1J its parameters are 3 = 0.4 μιη, A = 〇.l The application of the diffraction lattice can effectively convert the horizontally transmitted light into a vertical transmission In addition, the spectrum emitted by the light-emitting diode can be simultaneously filtered. 1276232 The light-emitting diode spectrum of the filter of the diffraction lattice is used to purify the color of the light emitted by the light-emitting diode. The polar body spectrum-filtering reduces the difference in wavelength of the light-emitting diode wafers manufactured by different wafers or different parts of the wafer. Please refer to the second figure for the illustration of the third embodiment of the present invention. Implementation: An example has a sapphire (Al2〇3) substrate (1) and a gallium nitride-based light-emitting diode structure (2) disposed thereon. A gallium nitride-based light-emitting diode structure (2) On, a two-dimensional Ai2〇3 % diffraction lattice (3) is formed. The Al2〇3 diffraction lattice (3) is formed by anodization of a film. The diffraction lattice structure is shown in the sixth diagram. The equation of the lateral spacing of the diffractive lattice ^/ can be expressed as a heart, where the - positive integer (w = H3 ·..), the wavelength of light produced by the light-emitting diode is 1 gallium nitride Refractive index. In order to make the diffusion with =1, 2, 3... most efficient, the diffraction of the 〇 order must be given _. This happens precisely when the depth of the cylindrical hole forming the diffraction lattice is ==1(2/+1)/2", / is a positive integer number or zero and their radius r must conform to the following equation dog" 2. Therefore, when the light-emitting diode is 4=0.5 μηη, and the diffraction lattice is ^, (4), the parameter is 〇.21 μηι m μιη (10). The application of the diffraction lattice can effectively laterally The transmitted light is converted into a vertical transmission, and the spectrum emitted by the light-emitting diode can be simultaneously filtered. The spectrum of the light-emitting diode filtered by the diffraction lattice is purified by the light-emitting 10 1276232 diode. In addition, the filtering of the light-emitting diode spectrum reduces the difference in wavelength of the light-emitting diode wafers manufactured by different wafers or different parts of the wafer. The illustration of the fourth embodiment of the present invention also invites Referring to the second figure, the present embodiment has a gallium arsenide (GaAs) substrate (1) and an illuminating aluminum indium gallium (AlGalnP)-based light-emitting diode structure (2) disposed thereon. On the aluminum indium gallium-based light-emitting diode structure (2), a two-dimensional Al2〇3 winding is formed. Lattice (3). The Al2〇3 diffraction lattice (3) is formed by anodization of an aluminum film. The diffraction lattice structure is not shown in Fig. 6. The lateral spacing of the diffraction lattice The equation of d can be expressed as ΑΛζ, where m is a positive integer (m = 1, 2, 3..), A is the wavelength of the light produced by the light-emitting diode, and π is the refractive index of AlGalnP. Let the diffusion with m=l, 2, 3... be the most efficient, and the diffraction of the 0th order must be suppressed. This happens precisely when the depth of the cylindrical hole forming the diffraction lattice is expressed as /2=4 (2 /+1)/2% / is a positive integer or zero, and their radius r must conform to the following equation γ=ά(7Ι4π)ιη ° Therefore, when the illuminating diode Α=0·6 μιη, diffraction The crystal lattice m = / = 0 Riji, Bei 1J The parameters are 3 = 〇 · 18 μηι, /2 = 0.99 μηι, r = 0.066 μιη. The application of the diffraction lattice can convert the laterally transmitted light into a vertical transmission. In addition, the spectrum emitted by the light-emitting diode can be simultaneously filtered. 11 1276232 The spectrum of the light-emitting diode filtered by the diffraction sigma is purified by the light emitted by the light-emitting diode. In addition, the illuminating diode spectrum is over-considered to reduce the difference in wavelength of light-emitting diode chips fabricated from different wafers or different parts of the wafer. In summary, the disclosed technical means It is true that there are invention patents such as "novelty", "progressiveness" and "available for industrial use", and pray that the bureau will give a patent to encourage innovation and no sense of morality. However, the above-mentioned drawings and descriptions only cite the preferred embodiments of the invention, and those who are familiar with the art, and the modifications or equivalent changes made by the sacred materials should still include the scope of patent application in this case. 12 I276232 [Simple description of the diagram] The first picture is a conventional light-emitting diode without a diffraction lattice, in which the light with an incident angle greater than the critical angle is captured in the wafer; The second figure is an image of a light-emitting diode chip having a diffraction lattice on the top surface, wherein the diffraction crystals convert the light transmitted laterally into the light of the vertical transmission wheel;
第三圖係為在發光二極體結構和基板之間的界面上具 :繞射晶格之發光二極體晶片之示意圖，其中，繞射晶格將 枳向傳輸的光線轉換成為垂直傳輸的光線； 第四圖係為繞射晶格的第一種變化實施例〆為繞射晶 之橫向間距，,為形成繞射晶袼六角區域之側邊長度； 第五圖係為繞射晶格的第二種變化實施例〆為繞射晶 之橫向間距，，為形成繞射晶格六角區域之侧邊長度；以及 第六圖係為繞射晶格的第三種變化實施例〆為繞射晶 L之橫向間距，r為形成繞射晶格圓柱孔的半徑。 【圖號說明】The third figure is a schematic diagram of a light-emitting diode wafer having a diffraction lattice at an interface between the light-emitting diode structure and the substrate, wherein the diffraction lattice converts the transmitted light into a vertical transmission. The fourth pattern is the first variation of the diffraction lattice. The lateral spacing of the diffraction crystals is the length of the side of the hexagonal region of the diffraction crystal. The fifth diagram is the diffraction lattice. A second variation of the embodiment is the lateral spacing of the diffractive crystals, which is the length of the sides forming the hexagonal region of the diffractive lattice; and the sixth embodiment is a third variation of the diffractive crystal lattice. The lateral spacing of the crystal L, r is the radius of the cylindrical hole forming the diffraction lattice. [Illustration number]
(1)基板 (2) 發光二極體結構 (3) 繞射晶格 (4) 橫向傳輸光線 (5) 垂直傳輸光線 13(1) Substrate (2) Light-emitting diode structure (3) Diffractive lattice (4) Transverse light transmission (5) Vertical transmission of light 13