TW201204881A - Process for producing single-crystal sapphire, and single-crystal sapphire substrate - Google Patents

Process for producing single-crystal sapphire, and single-crystal sapphire substrate Download PDF

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TW201204881A
TW201204881A TW100118637A TW100118637A TW201204881A TW 201204881 A TW201204881 A TW 201204881A TW 100118637 A TW100118637 A TW 100118637A TW 100118637 A TW100118637 A TW 100118637A TW 201204881 A TW201204881 A TW 201204881A
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single crystal
sapphire single
alumina
crucible
heating
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TW100118637A
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Chinese (zh)
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Tomohiro Shonai
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Showa Denko Kk
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    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/10—Inorganic compounds or compositions
    • C30B29/16—Oxides
    • C30B29/20—Aluminium oxides
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B15/00—Single-crystal growth by pulling from a melt, e.g. Czochralski method
    • C30B15/02—Single-crystal growth by pulling from a melt, e.g. Czochralski method adding crystallising materials or reactants forming it in situ to the melt
    • C30B15/04—Single-crystal growth by pulling from a melt, e.g. Czochralski method adding crystallising materials or reactants forming it in situ to the melt adding doping materials, e.g. for n-p-junction

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)

Abstract

A process for producing a sapphire ingot includes: a heating step (S101) in the solid phase in which solid aluminum oxide (alumina) filled in a crucible in a heating furnace is heated and held at a temperature less than the melting point (2050 DEG C); a melting step (S102) in which the aluminum oxide in the crucible is melted; a heating step (S103) in the liquid phase in which the aluminum oxide is heated and held at a temperature higher than the melting point thereof; a shoulder-part formation step (S105) in which a seed crystal is pulled up while being rotated to form a shoulder part beneath the seed crystal; and a straight-part formation step (S106) in which the shoulder-part is pulled up while being rotated via the seed crystal while the lower end part of the shoulder-part is kept in contact with the alumina melt to form a straight part beneath the shoulder part. Thus, a process for producing a single-crystal sapphire substrate with few metal impurities and crystal defects (air bubbles), and a single-crystal sapphire substrate are provided.

Description

201204881 六、發明說明： 【發明所屬之技術領域】 本發明係關於藍寶石單晶之製造方法及藍寶石單晶基 板。 【先前技術】 一般而言’具有III-V族化合物半導體層等的化合物 半導體層之半導體發光元件’係於藍寶石單晶等所構成的 基板上形成化合物半導體層’於其上進而設正極或負極等 之後，硏削及硏磨基板的被硏削面，其後，藉由切斷爲適 當的形狀而調製出發光元件晶片（參照專利文獻1)。 對於高品質之藍寶石單晶的育成技術，被提出了使用 矽濃度低的種晶的製法（專利文獻2)，減低氧化鋁融液中 的銷（Zr)不純物之製法（專利文獻3)等。 [先前技術文獻] [專利文獻] [專利文獻1]日本專利特開2008-177525號公報 [專利文獻2]日本專利特開2008-26064〇號公報 [專利文獻3]日本專利特開2008-08137〇號公報 【發明內容】 [發明所欲解決之課題] 然而，被層積化合物半導體層的藍寶石單晶基板，係 切出藉由柴氏（Czochralski)長晶法（CZ法）製造的單晶之錠 -5- 201204881 而得的。一般而言，在CZ法，由氧化銀融液成長藍寶石 單晶時，會由於製造條件的些微變動而導致藍寶石單晶產 生結晶缺陷、應變係屬已知。特別是直徑1 〇〇mm以上的 大口徑藍寶石錠，有必要進行不純物的控制、應變緩和技 術、溫度均勻性、溫度梯度等之精密控制，要製造跨整個 錠的結晶缺陷、應變、不純物都很少的結晶是困難的，所 以有必要檢討新的育成條件、與最佳化。 其中，以氣泡等結晶缺陷的減低較爲重要。特別是大 口徑基板，容易在結晶中取入氣泡，成爲品質降低的主要 原因。此外，氣泡在切斷步驟等，也會成爲破裂、龜裂的 原因，此外也是表面加工產率降低的原因。本案發明人發 現氣泡的產生原因，主要是在於特定的金屬元素。具體而 言，導出了氧化物的分解溫度接近於藍寶石的融點的鈉 (Na)、鋇（Ba)、釩（V)以及這些的化合物之減低對策是重要 課題。 前述金屬元素中的Na，在原料之高純度氧化鋁中含 有1〜20PPm程度，同時在作業環境與人體都存在著很多 ，所以有污染原料的可能性。 另一方面，在結晶缺陷（氣泡）、金屬不純物很多的藍 寶石單晶基板，於使化合物半導體層外延成長的步驟，會 有無法形成良質的化合物半導體層的情形。亦即，化合物 半導體層的品質，會影響半導體發光元件的發光效率、電 氣特性。 本發明之目的在於提供金屬不純物、結晶缺陷（氣泡） -6- 201204881 很少的藍寶石單晶基板之製造方法及藍寶石單晶基板。 [供解決課題之手段] 根據本發明，提供相關於以下[1]〜[8]之發明。 [1] 一種藍寶石單晶之製造方法，其特徵係包含：於 據柴氏（Czochralski)長晶法之藍寶石單晶提拉裝置，將 (N a)濃度1 ppm以上之氧化鋁原料’在超過氧化鋁的融 的溫度下，於坩鍋中以融溶的融液的狀態予以保持之在 相的加熱步驟，藉由使前述坩鍋中的附著於氧化鋁之前 融液的種晶旋轉同時提拉，朝向該種晶的下方形成直徑 大的肩部的肩部形成步驟，藉由使附著於前述融液的前 肩部旋轉同時提拉，於該肩部的下方形成圓柱狀的胴部 胴部形成步驟。 [2] 前項[1]記載之藍寶石單晶之製造方法，特徵爲 述在液相的加熱步驟’係於比氧化鋁的融點高30°C以 300 °C以下的溫度在高溫下進行的。 [3] 前項[1]或[2]記載之藍寶石單晶之製造方法，特 爲前述在液相的加熱步驟之前述融液’係由前述坩鍋的 部朝向上部，使該坩鍋中的氧化鋁原料融溶而形成的。 [4] 前項[1]記載之藍寶石單晶之製造方法，特徵爲 述在液相的加熱步驟之前’進而包含使前述坩鍋中的氧 鋁原料，保持在未達氧化鋁的融點的溫度下之在固相的 熱步驟。 [5] 前項[4]記載之藍寶石單晶之製造方法，特徵爲 根 鈉 點 液 述 變 述 之 前 上 徵 下 n· 刖 化 加 r. 刖 201204881 述在固相的加熱步驟，係在1200 °C以上且未達2050t的溫 度下進行.的。 [6] 前項[4]或[5]記載之藍寶石單晶之製造方法，特徵 爲前述在固相的加熱步驟之前述坩鍋中的氧化鋁原料，係 由前述坩鍋的下部朝向上部昇溫。 [7] —種藍寶石單晶基板，其特徵係以前項[1]記載之 藍寶石單晶之製造方法所製造的，鈉（Na)、鋇（Ba)及釩（V) 之分別的濃度均未達lppm，而直徑在100mm以上。 [8] —種藍寶石單晶基板，其特徵係以前項[4]記載之 藍寶石單晶之製造方法所製造的，鈉（N a)、鋇（B a)及釩（V) 之分別的濃度均未達lppm，而直徑在l〇〇mm以上。 [發明之效果] 根據本發明，與不具有本構成的場合相比，可得金屬 不純物、結晶缺陷（氣泡）很少的藍寶石單晶，可謀求表面 加工產率的提高’同時於藍寶石單晶基板上成膜出化合物 半導體層而製造的半導體發光元件，提高了發光特性、電 氣特性。 【實施方式】 以下，針對本發明之實施形態進行詳細說明。又，本 發明並不以下列實施形態爲限定內容，在其要旨的範圍內 可以進行種種變形而實施。此外，使用的圖面係供說明本 實施形態用之一例，並不代表實際的大小。 -8 - 201204881 <單晶提拉裝置I> 在本實施形態，使用可以育成1 00mm以上的大口徑 藍寶石單晶的特定之單晶提拉裝置（藍寶石單晶提拉裝置）1 ，藉由CZ法製造藍寶石單晶之錠（藍寶石錠30)。此處， 將製造藍寶石單晶錠30，標記爲製造藍寶石單晶。 圖1係說明單晶提拉裝置I之一例之圖》如圖1所示 ，單晶提拉裝置I，具備使由藍寶石單晶所構成的藍寶石 錠30成長之用的加熱爐10。加熱爐10具備絕熱容器11 。絕熱容器11具有圓柱狀的外形，於其內部被形成圓柱 狀的空間。絕熱容器1 1，例如係以組裝銷（Zr02)製的絕熱 材所構成的零件而被構成的。加熱爐10具備於內部空間 收容絕熱容器11之真空室14。加熱爐10，具備被貫通形 成於真空室14的側面，由真空室14的外部中介著真空室 1 4對絕熱容器1 1的內部供給氣體的氣體供給管1 2。同樣 地，具備被貫通形成於真空室1 4的側面，由絕熱容器1 1 的內部中介著真空室14往外部排出氣體的氣體排出管13 〇 於絕熱容器1 1的內側下方，坩鍋1 5以朝向鉛直上方 開口的方式配置。坩鍋1 5，例如係由銥（Ir)構成，收容融 溶氧化鋁而成的氧化鋁融液35。 加熱爐1 〇具備金屬製之加熱線圈1 6。加熱線圈1 6， 被繞拉於絕熱容器1 1的下部側的側面外側且成爲真空室 1 4的下部側的側面內側.的部位。加熱線圈1 6，係中介著 -9 - 201204881 絕熱容器Π而與坩鍋15的壁面成爲對向，同時可於上下 方向移動的方式配置。 加熱線圈1 6，例如由中空狀的銅管構成，被繞拉爲螺 旋狀，全體來看具有圓筒狀的形狀。在本實施形態，加熱 線圈1 6的上部側之內徑與下部側的內徑幾乎相同。藉此 ，藉由被繞拉的加熱線圈16被形成於其內部的空間成爲 圓柱狀。此外，通過圓柱狀的空間之加熱線圈16的中心 軸，成爲對水平方向幾乎垂直，亦即成爲沿著鉛直方向。 坩鍋1 5，被配置於藉由加熱線圈1 6形成的圓柱狀空間的 內側》接著，坩鍋15,被置於藉由加熱線圈16形成的圓 形狀區域的大致中央的部位》 加熱爐1〇，具備透過分別被設於絕熱容器11、真空 室14之上面的貫通孔而由上方往下伸的提拉棒17。提拉 棒1 7係以能夠進行鉛直方向的移動與以軸爲中心的旋轉 的方式被安裝的。又，被設於真空室14的貫通孔與提拉 棒17之間，設有未圖示之密封材。接著，於提拉棒17的 鉛直下方側之端部，被安裝著供安裝、保持使藍寶石錠30 成長之基礎的種晶3 1(參照後述之圖2)之用的保持構件18 〇 單晶提拉裝置I，具備使提拉棒17往鉛直上方拉起之 用的提拉驅動部19及使提拉棒17旋轉之用的旋轉驅動部 20。此處，提拉驅動部19係以馬達等構成，可以調整提 拉棒17之提拉速度。此外，旋轉驅動部20也以馬達等構 成，可以調整提拉棒17的旋轉速度。 -10- 201204881 單晶提拉裝置I，具備透過氣體供給管12往真空室 14內部供給氣體之氣體供給部21。於本實施形態，氣體 供給部21，供給混合由〇2源22供給的氧氣與由N2源23 供給的作爲非活性氣體之一例之氮氣之混合氣體。接著， 氣體供給部21，藉由改變氧氣與氮氣之混合比，而調整混 合氣體中的氧氣濃度。此外，也進行供給至真空室14內 部的混合氣體的流量調整。 單晶提拉裝置I，具備透過氣體排出管13由真空室 1 4內部排出氣體之排氣部24。排氣部24例如具備真空栗 等’可以進行真空室14內的減壓、或進行由氣體供給部 2 1供給的氣體之排氣。 單晶提拉裝置I，具備對加熱線圈1 6供給電流之線圈 電源25 »線圈電源25設定對加熱線圈16之電流供給的有 無以及供給的電流量。 此外，具備透過提拉棒17檢測出成長於提拉棒17的 下部側的藍寶石錠30的重量之重量檢測部27。此重量檢 測部2 7，例如被構成爲包含公知的重量感測器等。 進而’單晶提拉裝置I，具備使加熱線圈16移動於上 下方向的線圏驅動部2 8。又，替代使加熱線圈1 6移動於 上下方向，而使坩鍋15移動於上下方向亦可》 接著’單晶提拉裝置I，具備前述之提拉驅動部19' 旋轉驅動部20、氣體供給部21'排氣部24、線圈電源25 、及控制線圈驅動部2 8的控制部2 6。此外，控制部2 6根 據由重量檢測部27輸出的重量訊號，進行拉起的藍寶石 -11 - 201204881 錠3 0的結晶直徑的計算，反饋至線圈電源2 5。 <藍寶石錠（ingot)30> 圖2係使用圖1所示之單晶提拉裝置I所製造之藍寶 石錠30的構成之一例。 此藍寶石錠30具備：供使藍寶石錠30成長的基礎之 種晶3 1、延伸於種晶3 1的下部與此種晶3 1 —體化之肩部 32、延伸於此肩部32的下部與此肩部32 —體化之直胴部 (胴部）33、及延伸於直胴部33的下部與直胴部33 —體化 之尾部34。在本實施形態，於此藍寶石錠30，由上方之 種晶31側朝向下方的尾部34側藍寶石單晶成長於c軸方 向。 此處，肩部32具有由種晶31側朝向直胴部33側徐 徐擴大其直徑的形狀。此外，直胴部33具有由上方朝向 下方其直徑幾乎相同的形狀。又，直胴部33的直徑，被 設定爲比預先設計的藍寶石單晶基板11 〇(參照後述之圖4) 的直徑稍大之値。 又，直胴部3 3爲胴部。但是，由於是圓柱狀所以稱 爲直胴部。 本案發明人，發現氣泡發生是由於作爲氧化物等而含 有的金屬氧化物的分解所導致的，而導出藉由著眼於特定 元素的濃度，可以減低結晶缺陷。 亦即，於藍寶石錠30之育成前，除去存在於原料之 氧化鋁中的，在接近於藍寶石錠30的結晶育成溫度的溫 -12- 201204881 度會進行分解的金屬不純物，例如鈉（Na)、鋇（Ba)、釩（v) 是很重要的。其中，還發現以容易混入氧化鋁融液35,環 境中存在很多的Na，特別重要。又，這些之金屬不純物 多數是以氧化物的形式含有的。氣泡的原因，被導出來是 由於這些氧化物分解、蒸發之氣體，被取入藍寶石單晶之 藍寶石錠30所導致。 作爲除去這些金屬化合物的手段之一，在藍寶石淀30 之育成前，在高溫加熱（烘焙）藍寶石錠30的原料之氧化銘 會是有效的。 高溫之加熱最好在減壓下進行。此外，藉由對坩鍋15 的上部與下部賦予溫度差而進行加熱，促進對流也是適切 的方法。201204881 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to a method for producing a sapphire single crystal and a sapphire single crystal substrate. [Prior Art] Generally, a semiconductor light-emitting device having a compound semiconductor layer of a III-V compound semiconductor layer or the like is formed on a substrate made of a sapphire single crystal or the like to form a compound semiconductor layer on which a positive electrode or a negative electrode is further provided. After that, the boring surface of the substrate is honed and honed, and then the light-emitting element wafer is prepared by cutting into an appropriate shape (see Patent Document 1). In the production technique of a high-quality sapphire single crystal, a method for producing a seed crystal having a low cerium concentration (Patent Document 2), a method for reducing a pin (Zr) impurity in an alumina melt (Patent Document 3), and the like have been proposed. [PRIOR ART DOCUMENT] [Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-177525 (Patent Document 2) Japanese Patent Laid-Open Publication No. 2008-26064 No. [Patent Document 3] Japanese Patent Laid-Open No. 2008-08137 〇 公报 【 发明 发明 发明 发明 发明 发明 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而 然而Ingot-5- 201204881. In general, in the CZ method, when a sapphire single crystal is grown from a silver oxide melt, a sapphire single crystal is crystallized due to slight fluctuations in manufacturing conditions, and a strain system is known. In particular, large-diameter sapphire ingots with a diameter of 1 〇〇mm or more are necessary for precise control of impurity control, strain relaxation technology, temperature uniformity, temperature gradient, etc., and it is necessary to manufacture crystal defects, strains, and impurities throughout the entire ingot. Less crystallization is difficult, so it is necessary to review new breeding conditions and optimization. Among them, it is important to reduce the crystal defects such as bubbles. In particular, a large-diameter substrate is likely to take in bubbles in the crystal, which is a major cause of deterioration in quality. Further, in the cutting step or the like, the bubbles may cause cracking or cracking, and also cause a decrease in surface processing yield. The inventors of the present invention found that the cause of the bubble is mainly due to a specific metal element. Specifically, it has been an important issue to reduce the sodium (Na), barium (Ba), and vanadium (V) in which the decomposition temperature of the oxide is close to the melting point of sapphire and the reduction of these compounds. The Na in the above-mentioned metal element contains about 1 to 20 ppm of the high-purity alumina of the raw material, and there are many cases in the working environment and the human body, so there is a possibility of contaminating the raw material. On the other hand, in the sapphire single crystal substrate having a large number of crystal defects (bubbles) and metal impurities, in the step of epitaxially growing the compound semiconductor layer, a favorable compound semiconductor layer cannot be formed. That is, the quality of the compound semiconductor layer affects the luminous efficiency and electrical characteristics of the semiconductor light-emitting device. An object of the present invention is to provide a method for producing a sapphire single crystal substrate having few metal impurities and crystal defects (bubbles) -6-201204881 and a sapphire single crystal substrate. [Means for Solving the Problems] According to the present invention, the inventions related to the following [1] to [8] are provided. [1] A method for producing a sapphire single crystal, comprising: a sapphire single crystal pulling device according to a Czochralski crystal growth method, wherein a (N a) alumina raw material having a concentration of 1 ppm or more is exceeded At the melting temperature of the alumina, the phase heating step is maintained in the state of the melted melt in the crucible, and the seed crystal of the melt before the adhesion to the alumina in the crucible is simultaneously rotated. Pulling, a shoulder forming step of forming a shoulder having a large diameter toward the lower side of the seed crystal, and forming a cylindrical crotch portion below the shoulder by rotating the front shoulder attached to the melt while lifting Part forming step. [2] The method for producing a sapphire single crystal according to the above [1], characterized in that the heating step in the liquid phase is carried out at a temperature higher than a melting point of alumina by 30 ° C at a temperature of 300 ° C or lower. . [3] The method for producing a sapphire single crystal according to the above [1] or [2], wherein the melt in the liquid phase heating step is directed from the portion of the crucible toward the upper portion to cause the crucible The alumina raw material is melted and formed. [4] The method for producing a sapphire single crystal according to the above [1], characterized in that, before the heating step of the liquid phase, the temperature further comprises a temperature at which the oxyaluminum raw material in the crucible is maintained at a melting point of less than alumina. The thermal step in the solid phase. [5] The method for producing a sapphire single crystal according to the above [4], characterized in that the root sodium point liquid is described above and the upper part is n· 刖化 plus r. 刖201204881 The heating step in the solid phase is 1200 ° Above C and not at a temperature of 2050t. [6] The method for producing a sapphire single crystal according to the above [4] or [5] characterized in that the alumina raw material in the crucible in the heating step of the solid phase is heated from the lower portion of the crucible toward the upper portion. [7] A sapphire single crystal substrate characterized by being produced by the method for producing a sapphire single crystal according to the above [1], wherein the concentrations of sodium (Na), barium (Ba) and vanadium (V) are not respectively Up to 1ppm and diameter above 100mm. [8] A sapphire single crystal substrate characterized by the respective concentrations of sodium (N a), bismuth (B a ) and vanadium (V) produced by the method for producing a sapphire single crystal according to the above [4] None of them reached 1 ppm, and the diameter was above l〇〇mm. [Effects of the Invention] According to the present invention, compared with the case where the present configuration is not obtained, a sapphire single crystal having few metal impurities and crystal defects (air bubbles) can be obtained, and the surface processing yield can be improved. A semiconductor light-emitting device produced by forming a compound semiconductor layer on a substrate improves light-emitting characteristics and electrical characteristics. [Embodiment] Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made without departing from the spirit and scope of the invention. Further, the drawings used are for explaining an example of the embodiment, and do not represent actual sizes. -8 - 201204881 <Single crystal pulling device I> In the present embodiment, a specific single crystal pulling device (sapphire single crystal pulling device) 1 capable of cultivating a large diameter sapphire single crystal of 100 mm or more is used. The ingot of sapphire single crystal (sapphire ingot 30) was produced by the CZ method. Here, a sapphire single crystal ingot 30 will be produced, and is marked as a sapphire single crystal. Fig. 1 is a view showing an example of a single crystal pulling apparatus 1. As shown in Fig. 1, a single crystal pulling apparatus 1 includes a heating furnace 10 for growing a sapphire ingot 30 composed of a sapphire single crystal. The heating furnace 10 is provided with a heat insulating container 11. The heat insulating container 11 has a cylindrical outer shape and is formed into a cylindrical space inside thereof. The heat insulating container 1 1 is configured, for example, by a component made of a heat insulating material made of an assembly pin (Zr02). The heating furnace 10 is provided with a vacuum chamber 14 that accommodates the heat insulating container 11 in the internal space. The heating furnace 10 is provided with a gas supply pipe 12 that is formed to penetrate the side surface of the vacuum chamber 14 and that supplies a gas to the inside of the heat insulating container 1 by the vacuum chamber 14 through the outside of the vacuum chamber 14. In the same manner, the gas discharge pipe 13 that is formed in the side surface of the vacuum chamber 14 and through which the vacuum chamber 14 is externally discharged by the inside of the heat insulating container 1 is placed below the inside of the heat insulating container 1 1 and the crucible 15 It is arranged to face the opening directly above. The crucible 15 is made of, for example, Ir (Ir), and contains an alumina melt 35 made of melted alumina. The heating furnace 1 has a heating coil 16 made of metal. The heating coil 16 is wound around the outer side surface of the lower side of the heat insulating container 1 1 and becomes the inner side surface of the lower side of the vacuum chamber 14 . The heating coil 16 is interposed between the heat insulating container and the wall surface of the crucible 15 and is movable in the vertical direction. The heating coil 16 is composed of, for example, a hollow copper tube, and is wound into a spiral shape, and has a cylindrical shape as a whole. In the present embodiment, the inner diameter of the upper side of the heating coil 16 is almost the same as the inner diameter of the lower side. Thereby, the space formed inside the heating coil 16 that is wound is cylindrical. Further, the central axis of the heating coil 16 passing through the columnar space is almost perpendicular to the horizontal direction, that is, it is along the vertical direction. The crucible 15 is disposed inside the cylindrical space formed by the heating coil 16. Next, the crucible 15 is placed at a substantially central portion of the circular region formed by the heating coil 16." The crucible is provided with a pulling rod 17 that extends downward from the upper side through the through holes provided in the upper surface of the heat insulating container 11 and the vacuum chamber 14. The pulling rod 1 7 is attached so as to be movable in the vertical direction and in the rotation centered on the shaft. Further, a sealing member (not shown) is provided between the through hole provided in the vacuum chamber 14 and the pulling rod 17. Next, at the end portion on the vertical lower side of the pulling rod 17, a holding member 18 for mounting and holding the seed crystal 31 (see FIG. 2 described later) on which the sapphire ingot 30 grows is attached. The pulling device 1 includes a pulling drive unit 19 for pulling the pulling rod 17 vertically upward, and a rotation driving unit 20 for rotating the pulling rod 17. Here, the pulling drive unit 19 is constituted by a motor or the like, and the pulling speed of the pulling rod 17 can be adjusted. Further, the rotation driving unit 20 is also constituted by a motor or the like, and the rotation speed of the pulling rod 17 can be adjusted. -10- 201204881 The single crystal pulling device I includes a gas supply unit 21 that supplies a gas to the inside of the vacuum chamber 14 through the gas supply pipe 12. In the present embodiment, the gas supply unit 21 supplies a mixed gas of oxygen supplied from the helium source 22 and nitrogen gas supplied as an inert gas from the source N2. Next, the gas supply unit 21 adjusts the oxygen concentration in the mixed gas by changing the mixing ratio of oxygen and nitrogen. Further, the flow rate of the mixed gas supplied to the inside of the vacuum chamber 14 is also adjusted. The single crystal pulling device I includes an exhaust portion 24 that discharges gas from the inside of the vacuum chamber 14 through the gas discharge pipe 13. The exhaust unit 24 is provided with, for example, a vacuum pump or the like, which can perform pressure reduction in the vacuum chamber 14 or exhaust gas supplied from the gas supply unit 21 . The single crystal pulling device I includes a coil that supplies a current to the heating coil 16. The power supply 25 » The coil power supply 25 sets the amount of current supplied to the heating coil 16 and the amount of current supplied. Further, the weight detecting portion 27 that detects the weight of the sapphire ingot 30 that has grown on the lower side of the pulling rod 17 is detected by the pulling rod 17. The weight detecting unit 27 is configured, for example, to include a known weight sensor or the like. Further, the single crystal pulling device 1 includes a turn driving unit 28 that moves the heating coil 16 in the up and down direction. Further, instead of moving the heating coil 16 in the vertical direction, the crucible 15 may be moved in the vertical direction. Next, the single crystal pulling device I may be provided with the above-described pulling drive unit 19', the rotation driving unit 20, and the gas supply. The portion 21' is an exhaust unit 24, a coil power supply 25, and a control unit 26 that controls the coil drive unit 28. Further, the control unit 26 calculates the crystal diameter of the sapphire -11 - 201204881 ingot 30 which is pulled up based on the weight signal output from the weight detecting unit 27, and feeds it back to the coil power source 25. <Sapphire ingot 30> Fig. 2 is an example of a configuration of a sapphire ingot 30 manufactured by using the single crystal pulling device 1 shown in Fig. 1 . The sapphire ingot 30 includes a seed crystal 3 1 for growing the sapphire ingot 30, a shoulder portion 32 extending from the lower portion of the seed crystal 31 and the crystal 3 1 , and a lower portion extending over the shoulder portion 32 The straight portion (the crotch portion) 33 that is formed integrally with the shoulder portion 32, and the tail portion 34 that extends from the lower portion of the straight portion 33 and the straight portion 33 are formed. In the present embodiment, the sapphire ingot 30 is grown in the c-axis direction by the sapphire single crystal on the side of the tail portion 34 which is directed downward from the upper seed crystal 31 side. Here, the shoulder portion 32 has a shape in which the diameter of the seed crystal 31 side gradually increases toward the straight portion 33 side. Further, the straight portion 33 has a shape in which the diameter is almost the same from the upper side toward the lower side. Further, the diameter of the straight portion 33 is set to be slightly larger than the diameter of the sapphire single crystal substrate 11 预先 (see Fig. 4 to be described later) which is designed in advance. Further, the straight portion 3 3 is a crotch portion. However, since it is cylindrical, it is called a straight part. The inventors of the present invention have found that the occurrence of bubbles is caused by the decomposition of the metal oxide contained as an oxide or the like, and the derivation of the crystal defects can be reduced by focusing on the concentration of the specific element. That is, before the sapphire ingot 30 is grown, the metal impurities present in the alumina of the raw material, which are decomposed at a temperature of from -12 to 201204881, which is close to the crystallization temperature of the sapphire ingot 30, such as sodium (Na), are removed. , 钡 (Ba), vanadium (v) is very important. Among them, it has been found that it is particularly important to easily mix in the alumina melt 35, and a large amount of Na exists in the environment. Moreover, most of these metal impurities are contained in the form of oxides. The reason for the bubbles is derived from the sapphire ingot 30 of the sapphire single crystal which is decomposed and evaporated by these oxides. As one of the means for removing these metal compounds, it is effective to heat (bake) the raw material of the sapphire ingot 30 at a high temperature before the sapphire lake 30 is grown. The heating at a high temperature is preferably carried out under reduced pressure. Further, heating by heating the upper portion and the lower portion of the crucible 15 to promote convection is also suitable.

Na20 分解溫度爲 1 950°C，BaO 沸點爲 2000°C，V205 分解溫度爲1750 °C。因而，藉由高溫之加熱，可以在藍寶 石錠30之育成前使這些金屬氧化物分解或者揮發，可以 抑制往藍寶石錠30之氣泡、金屬之取入。 另一方面，成爲Na源的氯化鈉（NaCl)，會有由環境 或作業員往原料混入的情形。NaCl的融點爲80 1°C，沸點 爲14131。主要，藉由在原料融解之前的固相狀態進行加 熱使其蒸發，可以抑制往藍寶石錠3 0之取入。 本方法之外，進行原料之氧化鋁的精製或前處理，構 成絕熱容器11的絕熱材之高純度化、真空室14內的氛圍 的清淨化等，抑制不純物的混入的對策也是有效的。 氧化鋁在固相的狀態進行加熱的場合之加熱溫度，最 -13- 201204881 好是前述3個金屬氧化物開始分解或者蒸發的溫度，考慮 到NaCl在減壓下蒸發，最低也要在1 200°C以上，較佳者 爲1 750 °C以上。在固相進行的緣故，最好是未達氧化鋁的 融點（2 050°C)，較佳者爲未達2000°C，又更適切的爲未達 1 8 00°C。在固相的狀態進行加熱的場合，具有分解物、蒸 發物容易往氛圍中放出的優點。 藉此，發現伴隨著藍寶石單晶基板11〇(參照後述之圖 4)之金屬的不純物濃度之減低，可以減低藍寶石單晶基板 110內的氣泡。即使是細微的氣泡，也被認爲會對藍寶石 單晶基板110上外延成長的III族化合物半導體層100(參 照後述之圖4)之膜質造成影響。藉由這些方法，可以減低 大口徑的藍寶石錠30中的Na濃度，安定地達成未滿 lppm的高純度的藍寶石單晶之育成。進而，藉由使條件 適切化，達成了未滿0.5ppm的Na濃度。 <製造藍寶石錠30的步驟> 圖3係供說明使用圖1所示之單晶提拉裝置I，製造 圖2所示之藍寶石錠30的步驟之用的流程圖。 於藍寶石錠30之製造，首先執行藉由加熱被塡充於 加熱爐1〇內的坩堝15內之固體氧化鋁，於未達融點 (2050°〇的溫度進行加熱（烘焙）而予以保持之在固相的加 熱步驟（步驟101)。 接著’執行將坩鍋15內的氧化鋁融解的融解步驟（步 驟 102)。 -14- 201204881 接著，執行在比氧化鋁的融點更高的溫度持續加熱（ 烘焙）予以保持之在液相的加熱步驟（步驟103) ° 接著，使種晶31的下端部接觸於氧化銘的融液亦即 氧化鋁融液3 5(步驟1 04) °在該狀態’執行藉由使種晶3 1 旋轉同時往上方提拉，在種晶31的下方形成肩部32之肩 部形成步驟（步驟1〇5) » 接著，在使肩部32的下端部接觸於氧化銘融液35的 狀態，執行作爲透過種晶31使肩部32旋轉同時往上方提 拉，而於肩部32的下方形成直胴部（胴部）33之直胴部形 成步驟（胴部形成步驟）（步驟1〇6)。 進而接著，在使直胴部33的下端部接觸於氧化鋁融 液3 5的狀態，執行藉由透過種晶31及肩部3 2使直胴部 33旋轉同時往上方提拉而由氧化鋁融液35拉離，在直胴 部33的下方形成尾部34之尾部形成步驟（步驟107)。 其後，在所得到的藍寶石錠3 0冷卻後取出至加熱爐 10的外部，結束一連串的製造步驟。 其次，在錠狀態下，進行藍寶石錠30的熱處理，緩 和由於錠內的溫度分布而產生的應變。例如，藍寶石錠30 爲直徑相當於100mm的話，在1 200°C以上，實施3小時 ，較佳者爲以1 500°C以上進行5小時以上的條件實施熱處 理。昇溫/降溫速度爲1.0°C/分〜10.0°C/分，較佳者爲 2.0°〇/分〜7.0°(1；/分。 這些條件，隨著藍寶石單晶基板1 1 0(參照後述之圖4) 的直徑（尺寸）變大，例如變成直徑150mm的話，使溫度提 -15- 201204881 高、時間拉長的條件會成爲適切的範圍。 其次，如此進行所得到的藍寶石錠3 0，首先分別在肩 部32與直胴部33之邊界及在直胴部33與尾部34之邊界 切斷，切出直胴部33。其次，切出的直胴部33，進而例 如藉由複線式線鋸’在與藍寶石錠30的長邊方向直交的 方向上被切斷，硏磨表面而成爲藍寶石單晶基板110。此 時，本實施形態之藍寶石錠3 0，係晶體成長於藍寶石單晶 的c軸方向，所以所得的藍寶石單晶基板110的主面，爲 藍寶石單晶的C面（（0001)面）。 又，隨著化合物半導體層的成長條件不同，亦可由C 面附加傾斜角（offangle)而加工基板的主面。此外，亦可 在C面以外進行切出。 接下來，針對前述各步驟進行具體說明。但此處由步 驟1 〇 1之在固相的加熱步驟之前所執行的準備步驟開始依 序說明。 (準備步驟） 在準備步驟，首先，在提拉棒17之保持構件18安裝 種晶31’設定於特定的位置。此時，於種晶31的下端使 藍寶石的C面（（0001 )面）露出。其次，在坩堝15內塡充氧 化銘之原料’使用銷製造的絕熱材所構成的零件組裝絕熱 容器11°又’原料之氧化鋁，爲粉末或細微的結晶片。原 料之氧化鋁中的Na濃度爲1〜1 〇PPm程度。進而，爲了 把純度提高到未滿lppm，有必要採精製處理等高階的技 -16- 201204881 術，會招致生產性降低，與原料成本的提高。此外，施以 徹底之Na污染對策的工作環境、作業方法的完善，也會 導致生產性的降低。 另一方面’原料中的V、Ba，爲未滿lppm的低濃度 ，但隨著製造商、製造日期的不同，會有濃度變化的情形 〇 接著，在不進行從氣體供給部21供給氣體的狀態下 ，使用排氣部24減壓絕熱容器1 1內。 此時，絕熱容器11內，被減壓至IPa以下，較佳者 爲10'3Pa以下，進而又更佳者爲1〇·5Ρ&以下。 (在®相的加熱步驟） 其次，把被充塡至坩鍋15內的固體之氧化鋁，於 1200°C以上且未達氧化鋁的融點（2050°C)的溫度進行加熱（ 烘焙）。亦即，氧化鋁不融解而成爲固相之加熱。又，加 熱的溫度超過1 8 00°C的話，藍寶石錠30的原料之氧化鋁 的粉末或結晶片彼此融接，阻礙金屬化合物的分解及金屬 化合物的揮發。因而，加熱的溫度以1 200 °C以上且未滿 1800°C爲較佳。 此外，於在固相的加熱步驟，由充塡原料的氧化鋁的 坩鍋1 5的最下端開始進行加熱，·由坩鍋丨5的下方往上方 依次進行原料的氧化鋁的加熱爲較佳。藉此，促進NaCl 等之金屬化合物及金屬化合物分解而得的金屬、氧氣等之 氣體的揮發，所以較佳。 -17- 201204881 坩鍋1 5的加熱，係藉由線圈電源2 5對加熱線圈1 6 供給高頻的交流電流（在以下的說明稱之爲高頻電流）而進 行的。由線圈電源25對加熱線圈16供給高頻電流時，加 熱線圏1 6的周圍磁束會反覆地產生/消滅。接著，以加熱 線圈16產生的磁束，透過絕熱容器11橫切坩堝15時， 在坩堝15的壁面產生妨礙該磁場變化的磁場，藉此在坩 堝15內產生渦電流。接著，坩堝15藉由渦電流（I)而產生 比例於坩堝15的表面電阻（R)之焦耳熱（W = I2R)，而使坩 堝15被加熱。坩鍋15被加熱，伴此，被收容於坩鍋15 內的氧化鋁也被加熱。 接著，在由坩鍋15的下方往上方進行加熱時，藉由 線圈驅動部28，使加熱線圏1 6的上下方向之中心位置移 動至坩鍋15的下端部時，由線圈電源25對加熱線圈16 通電’開始坩鍋1 5的誘導加熱，同時藉由線圈驅動部2 8 ’徐徐使加熱線圈16往上方移動即可。 又’坩鍋15，於鄰接加熱線圈1 6的部分被加熱，但 藉由熱傳導，坩鍋15全體的溫度也逐漸上升❶ 在固相的加熱步驟，至少進行1小時以上，較佳者爲 進行2小時以上。考慮到生產性，以不滿1 〇小時爲較佳 又’爲了促進金屬化合物及金屬化合物分解而得的金 屬、氧氣等之氣體的揮發，絕熱容器11內以保持在減壓 狀態爲較佳。以外，通以非活性氣體爲較佳。 -18- 201204881 (融溶步驟） 接著，使坩鍋15內的氧化鋁完全融解’成爲氧化銀 融液3 5。 由充塡原料的氧化鋁的坩鍋1 5的最下端開始使氧化 鋁的融解，由坩鍋15的下方往上方依序進行原料的氧化 鋁的融解爲較佳。於此，在固相的加熱步驟結束之後，藉 由線圈驅動部2 8，使加熱線圈1 6的上下方向之中心位置 移動往坩鍋15的下端部時，把供成爲使氧化鋁完全融解 的溫度之用的電流，由線圈電源2 5對加熱線圈1 6通電， 同時藉由線圈驅動部28，徐徐使加熱線圈16往上方移動 即可》 藉此，促進金屬化合物及金屬化合物分解而得的金屬 、氧氣等之氣體的揮發。此時，使氧化鋁急速融解的話， 金屬化合物及金屬化合物分解而得的金屬、氧氣等氣體被 排出之前被殘留於氧化鋁融液35中。因而，直到使原料 之氧化鋁完全融解爲止至少必須要3小時以上，較佳者爲 花費1 0小時以上。 又，於融溶步驟，也爲了促進金屬化合物及金屬化合 物分解而得的金屬、氧氣等之氣體的揮發，絕熱容器11 內以保持在減壓狀態爲較佳。以外，通以非活性氣體爲較 佳。 (在液相的加熱步驟） 接著，把氧化鋁融液35保持在比氧化鋁的融點更高 -19- 201204881 3 0°C〜3 00°C的溫度。加熱溫度比此溫度範圍更低的話，分 解物、氣泡不容易脫離，應該在數小時的處理之下是沒有 效果的，必須要長時間的加熱，所以生產性顯著低落。另 —方面，加熱溫度比此溫度範圍更高的場合，坩鍋1 5、絕 熱容器11等加熱爐10的損傷會變大，存在著裝置上的極 限。此時，原料之氧化鋁融溶成爲液相。保持的時間例如 爲2〜2 0小時。 又，於在液相的加熱步驟，也爲了促進金屬化合物及 金屬化合物分解而得的金屬、氧氣等之氣體的揮發，絕熱 容器11內以保持在減壓狀態爲較佳。以外，通以非活性 氣體爲較佳。 又，在固相的加熱步驟及在液相的加熱步驟之溫度及 時間只要隨著放入原料之氧化鋁的坩鍋15的材質及原料 之氧化鋁的粉末或結晶片所含的不純物之金屬化合物的濃 度而改變即可。 (肩部形成步驟） 在肩部形成步驟，氣體供給部21使用02源22及N2 源23把氧氣與氮氣以特定的比例混合後之混合氣體供給 至絕熱容器1 1內。但是在肩部形成步驟，如稍後詳述， 不一定要供給氧氣與氮氣之混合氣體，例如僅供給氮氣亦 可〇 此外，線圈電源25接著對加熱線圈1 6供給高頻電流 ，透過坩堝1 5加熱氧化鋁融液3 5。 -20- 201204881 進而，提拉驅動部19使提拉棒17下降而使被安裝於 保持構件18的種晶31的下端停止於與坩堝15內的鋁融 液35接觸的位置後，使提拉棒17以第1提拉速度進行提 拉。 進而此外，旋轉驅動部20使提拉棒17以第1旋轉速 度旋轉。 如此一來，種晶31在其下端部浸於氧化鋁融液35的 狀態下被旋轉同時提拉，在種晶31的下端，形成朝向鉛 直下方擴開的肩部32。 又，在製造供獲得所謂4吋（直徑100mm)晶圓的藍寶 石錠30的場合，在肩部32的直徑幾乎成爲120mm程度 的時間點，結束肩部形成步驟。氣泡，是直徑越大的場合 越容易取入。 (直胴部形成步驟） 在直胴部形成步驟，氣體供給部21使用〇2源22及 N2源23把氧氣與氮氣以特定的比例混合，把氧濃度設定 爲0.6%以上3.0%以下的範圍之混合氣體供給至絕熱容器 1 1內。 此外’線圈電源25接著對加熱線圈1 6供給高頻電流 ，透過坩堝15加熱氧化鋁融液35。 進而’提拉驅動部19以第2提拉速度提拉提拉棒17 。此處第2提拉速度，亦可爲與肩部形成步驟之第1提拉 速度相同的速度，亦可爲不同之速度。 -21 - 201204881 進而此外，旋轉驅動部20使提拉棒17以第2旋轉速 度旋轉。此處，第2旋轉速度，亦可爲與肩部形成步驟之 第1旋轉速度相同的速度，亦可爲不同之速度》 與種晶3 1 —體化的肩部3 2，在其下端部浸於氧化鋁 融液3 5的狀態被旋轉同時提拉，所以在肩部3 2的下端部 ，較佳者爲形成圓柱狀之直胴部33。直胴部33的直徑， 只要是比特定的口徑還大即可。 又，於直胴部形成步驟，被提拉往鉛直上方的直胴部 33之下端，維持於與氧化鋁融液35接觸的狀態。 (尾部形成步驟） 在尾部形成步驟，氣體供給部21使用02源22及N2 源23把氧氣與氮氣以特定的比例混合，把將氧濃度設定 爲比前述直胴部形成步驟更高之混合氣體供給至絕熱容器 11內。但是，尾部形成步驟之混合氣體中之氧濃度設定在 1.0%以上且5.0%以下的範圍》 此外’線圈電源25接著對加熱線圈16供給高頻電流 ，透過坩堝1 5加熱氧化鋁融液3 5。 進而，提拉驅動部19以第3提拉速度提拉提拉棒17 。此處第3提拉速度’亦可爲與肩部形成步驟之第1提拉 速度或者直胴部形成步驟之第2提拉速度相同的速度，亦 可爲與這些不同之速度。 進而此外，旋轉驅動部20使提拉棒17以第3旋轉速 度旋轉。此處，第3旋轉速度，亦可爲與肩部形成步驟之 -22- 201204881 第1旋轉速度或直胴部形成步驟之第2旋轉速度相同的速 度，亦可爲與這些不同之速度。 又’於尾部形成步驟之最終，尾部34之下端，維持 於與氧化鋁融液3 5接觸的狀態。 接著’經過預定的時間之尾部形成步驟之最終階段， 藉由提拉驅動部19使提拉棒17之提拉速度增加而使提拉 棒17進而往上方提拉，而使尾部34之下端脫離氧化鋁融 液35»藉此，得到圖2所示之藍寶石錠30» 又，在本實施形態，使用混合氧與氮之混合氣體，但 是不以此爲限，例如使用混合氧與作爲非活性氣體之一例 之氬氣亦可。 此外，在本實施形態，使用所謂電磁誘導加熱方式， 進行坩堝1 5的加熱，但是不以此爲限，例如採用電阻加 熱方式亦可。在電阻加熱方式，可以使坩鍋15旋轉的構 造的場合，於各加熱步驟，最好是爲了攪拌而使坩鍋15 旋轉。 由如前所述所製造的藍寶石錠30，製造如前所述的藍 寶石單晶基板110。藍寶石單晶基板110，藉由光學顯微 鏡，目視觀察有無氣泡，判斷氣泡之有無。此時，可觀察 到的氣泡大小爲1 μ m以上。 此外，藍寶石單晶基板110的表面，作爲半導體發光 元件（LC)使用的場合，爲了提高化合物半導體層的結晶性 ，提高發光效率，最好被施以平滑化或凹凸加工。 又，如前所述所製造的藍寶石錠30’在與藍寶石錠 -23- 201204881 30的長邊方向直交的方向上進行切斷的步驟以及硏磨表面 的步驟之破裂或龜裂等的發生非常少，具良好的加工產率 <半導體發光元件（LC)> 其次，說明使用藉由前述之藍寶石錠30的製造方法 ，所製造的藍寶石單晶基板110，所製造的半導體發光元 件（LC)。 於本實施形態，半導體發光元件（LC)，係在直徑 100mm、厚度約900μιη的藍寶石單晶基板110(參照後述之 圖4)上形成III族化合物半導體層，接著，把成膜了 III 族化合物半導體層的藍寶石單晶基板11〇的背面硏削至成 爲預定的厚度，經過硏磨（lapping)處理後，切斷爲晶片的 大小而形成的。 其次，說明藉由本實施形態適用的半導體發光元件 (LC)之製造方法所製造的半導體發光元件（LC)的構成。於 本實施形態製造的半導體發光元件（LC)，具有藍寶石單晶 基板110，與被成膜於基板上的化合物半導體層。構成化 合物半導體層的化合物半導體，例如可以舉出III-V族化 合物半導體，π-νι族化合物半導體，IV-IV族化合物半導 體等。在本實施形態，以III-V族化合物半導體爲佳，其 中又以in族氮化物半導體爲佳。以下，以具有由III族 氮化物化合物半導體所構成的化合物半導體層之半導體發 光元件（LC)爲例進行說明。 24 - 201204881 圖4係說明本實施形態製造的半導體發光元件（LC)之 一例之圖。 如圖4所示，半導體發光元件（LC)，於被形成在藍寶 石單晶基板110上的中間層120上，具有下底層130與 III族化合物半導體層1〇〇。111族化合物半導體層1〇〇, 依序被層積η型半導體層140、發光層150、p型半導體層 160。把形成半導體層的藍寶石單晶基板110表面以配置 多數細微的凸形狀的方式進行加工，因爲有提高發光輸出 的效果，所以是較佳的做法。 進而，於Ρ型半導體層160上被層積透明正極170, 於其上被形成正極焊墊180，同時於被形成在η型半導體 層140的η型接觸層140a之露出區域140c被層積負極 190° 在此，被成膜於下底層130上的η型半導體層140, 具有η型接觸層140a及η型覆蓋（clad)層140b。發光層 150，具有交互層積障壁層150a及井層15 0b的構造》ρ型 半導體層160,被層積ρ型覆蓋層16 0a及ρ型接觸層 1 6 Ob 0 在本實施形態，被成膜於藍寶石單晶基板110上的化 合物半導體層（中間層120、下底層130及III族化合物半 導體層1〇〇合起來之層）的合計厚度，較佳者爲3μηι以上 ，進而更佳者爲5μηι以上，進而又更佳者爲8μιη以上。 此外，這些的合計厚度，最好是1 5μπι以下爲佳。 其次，說明構成半導體發光元件（LC)的各層的材料。 -25- 201204881 (中間層120) 在本實施形態，藉由有機金屬化學氣相成長法（mocvd) 形成III族化合物半導體層100時’最好將發揮緩衝功能 的中間層120設於藍寶石單晶基板110上。特別是’中間 層120爲單晶構造，從緩衝功能的面來看是較佳的。把具 有單晶構造之中間層120成膜於藍寶石單晶基板110上的 場合，中間層1 20之緩衝功能有效發揮作用，所以於中間 層120上成膜之下底層130與III族化合物半導體層100 ，成爲具有良好配向性及結晶性之結晶膜。 中間層120，以含有鋁較佳，以含有III族氮化物之 氮化鋁特佳。作爲構成中間層1 20的材料，只要是以一般 式AlGalnN(氮化鋁鎵銦）表示之ΙΠ族氮化物化合物半導 體即可沒有特別限定。進而作爲V族含有砷或磷亦可。中 間層120，包含鋁的組成的場合，以氮化鎵鋁（AlGaN)較佳 ，ΙΠ族元素之中鋁之組成在50%以上者較佳。 (下底層130) 作爲使用於下底層130之材料，使用含鎵之III族氮 化物（GaN系化合物半導體），特別是可是適切地使用 AlGaN或GaN。下底層130之膜厚最好爲0.1 μιη以上，更 佳者爲〇.5μηι以上，進而更佳者爲Ιμιη以上。 (η型半導體層140) -26- 201204881 η型半導體層140，由η型接觸層140a及η型覆蓋 (clad)層140b所構成。作爲η型接觸層140a，與下底層 130同樣使用GaN系化合物半導體。此外，構成下底層 130及η型接觸層140a的氮化鎵系化合物半導體以相同組 成較佳，這些之合計膜厚設定於Ο.ίμηι〜20μΓη之範圍，較 佳者爲0.5μηι〜15μηι、進而更佳者爲設定在Ιμηι〜12μιη 之範圍。η型接觸層140a因爲要流通電流，所以很薄的場 合電阻變高在電氣特性上不佳。此外，厚的場合，成長時 間、材料費增加，由生產性、成本面來看，並不佳。 η型覆蓋層140b，可以藉由AlGaN、GaN、GalnN等 來形成。此外，作爲這些構造之異性（hetero)接合或複數 次層積之超格子構造亦可。採GalnN的場合，最好是比構 成後述的發光層150的井層150b之GalnN的能帶間隙更 大較佳。η型覆蓋層140b的膜厚，最好爲5nm〜500nm， 更佳者爲5nm〜100nm之範圍。 (發光層150) 發光層150，係交互反覆層積由氮化鎵系化合物半導 體所構成之障壁層150a、及含有銦的氮化鎵系化合物半導 體所構成之井層150b，且於η型半導體層140側及p型半 導體層160側被配置障壁層150a的順序層積而形成的。 在本實施形態，發光層150,係交互反覆層積6層障壁層 1 50a與5層井層1 50b。 於井層150b，作爲含銦的氮化鎵系化合物半導體，例 -27- 201204881 如可以使用Gai-sInsN(0<s<0.4)等氮化鎵銦。 作爲障壁層150a’可以適切使用含銦之氮化鎵系化 合物半導體所構成的井層1 5 Ob能帶間隙能量更大的 AUGa^NiOScSO.S)等氮化鎵系化合物半導體。 (P型半導體層160) p型半導體層160，係由p型覆蓋層160a及p型接觸 層160b所構成。作爲p型覆蓋層160a，較佳者可以舉出 AldGa1.dN(0<d^0.4) ° p型覆蓋層160a的膜厚，最好爲 lnm〜400nm，更佳者爲5nm〜l〇〇nm。 作爲P型接觸層160b，可以舉出至少包含AleGai_eN (0Se<0.5)而成的氮化鎵系化合物半導體層。p型覆蓋層 160b的膜厚，沒有特別限定，但以i〇nm〜500nm較佳， 更佳者爲50nm〜200nme (透明正極1 70) 作爲構成透明正極170的材料，例如可以舉出 ITO(In203-Sn〇2)、ΑΖΟ(ΖηΟ-Α12〇3)、ιζ〇(Ιη203-ΖηΟ)、 GZO(ZnO-Ga2〇3)等從前公知的材料。此外，透明正極ι7〇 的構造沒有特別限定，可以採用從前公知的構造。透明正 極170，亦可以覆蓋p型半導體層16〇上之幾乎全面的方 式形成’亦可形成爲格子狀或樹形狀。 (正極焊墊180) -28- 201204881 作爲形成於透明正極170上的電極之正極焊墊180, 例如由從前公知之金、鋁、鎳、銅等材料所構成。正極焊 墊180的構造沒有特別限定，可以採用從前公知的構造。 正極焊墊180的厚度爲l〇〇nm〜l，000nm之範圍內， 較佳者爲300nm〜500nm之範圍內。 (負極1 90) 如圖4所示，負極190，係於被成膜於藍寶石單晶基 板110上的中間層120及下底層130之上進而成膜的III 族化合物半導體層100(n型半導體層140、發光層150及 P型半導體層16 0)，以接於η型半導體層140之η型接觸 層140a的方式被形成。因此，形成負極190時，除去ρ 型半導體層160、發光層150以及η型半導體層140之一 部分，形成η型接觸層140a的露出區域140c，於此上形 成負極1 90。 作爲負極190的材料，各種組成及構造之負極係已知 ，可以無任何限制地使用這些週知的負極，可以用此技術 領域廣爲人知的慣用手段來設置。 在本實施形態，首先，於藍寶石單晶基板110上，以 電漿活化含v族元素的氣體與金屬材料使其反應，成膜由 III族氮化物所構成的中間層120。接著’於成膜的中間層 120上，依序層積下底層130、η型半導體層140、發光層 150、及ρ型半導體層160。 在本實施形態，於藍寶石單晶基板1 10上使111族氮 -29- 201204881 化物半導體結晶外延成長時，中間層120最好是使用濺鍍 法，把以電漿活化而反應的原料成膜於藍寶石單晶基板 110上形成。此處，V族元素爲氮，成膜中間層12〇時的 氣體中之氮的氣體分率爲50%〜99%以下的範圍’同時使 中間層1 20形成爲單晶構造。藉此，在短時間內結晶性良 好的中間層120，作爲具有向異性的配向膜被成膜於藍寶 石單晶基板1 1 〇上。結果，於中間層1 20上，與不設中間 層120的場合相比，可成長結晶性良好的III族氮化物化 合物半導體。 在本實施形態，藉由濺鍍法形成中間層120之後，於 其上，最好藉由有機金屬化學氣相成長法（MOCVD)，依序 形成下底層130、η型半導體層140、發光層150及p型半 導體層160。 在MOCVD法，作爲攜帶氣體，例如使用氫（HO或氮 (Νζ)等。作爲ΠΙ族原料之鎵源，使用三甲基鎵（TMG)、三 乙基鎵（TEG)等。作爲鋁源，使用三甲基鋁（ΤΜΑ)、三乙 基鋁（TEA)等。作爲銦源，使用三甲基銦（ΤΜΙ)、三乙基銦 (TEI)等。作爲V族原料之氮源，使用氨（Nh3)、聯氨 (N2H4)等。 作爲摻雜物’於η型作爲矽原料使用單矽烷（SiH4)、 二矽烷（Si2H6)等。做爲鍺原料，可以利用鍺烷氣體（GeH4) 、四甲基鍺（（CHshGe)、四乙基鍺（（C2H5)4Ge)等有機鍺化 合物。 又’氮化鍺系化合物半導體除了 Al、Ga、In以外， -30- 201204881 亦可含有其他元素。例如可以舉出Ge、Si、Mg、Ca、Zn 、Be等之摻雜元素。進而，不限於故意添加的元素，亦 可包含依存於成膜條件而必然包含的不純物、或是原料、 反應管材質所含之微量不純物。 另外，藉由MOCVD法形成下底層130後，以濺鍍法 形成η型接觸層140a及η型覆蓋層140b之各層，以 MOCVD法形成其上之發光層150，接著以反應性濺鍍法 形成構成P型半導體層160的p型覆蓋層160a及p型接 觸層1 60b i各層亦可。 於前述之直徑100mm、厚度約900μιη的藍寶石單晶 基板110上形成中間層120、下底層130及III族化合物 半導體層1〇〇後，於ΠΙ族化合物半導體層100之ρ型半 導體層160上被層積透明正極170，於其上被形成正極焊 墊180。進而，形成在η型半導體層140的被形成於η型 接觸層140a的露出區域140c設有負極190的晶圓。 前述的成膜了化合物半導體層的藍寶石單晶基板110 ，在其後將藍寶石單晶基板1 1 〇之被硏削面（背面），硏削 及硏磨至成爲預定的厚度。在本實施形態，於市售之硏削 機（未圖示）安裝晶圓，藉由硏削步驟，使晶圓的藍寶石單 晶基板1 10的厚度例如由約900μιη減少至120μιη。 接著，被調整藍寶石單晶基板1 1 〇的厚度之晶圓，例 如藉由切斷爲3 50μηι正方之正方形，形成在藍寶石單晶基 板110上被成膜中間層120、下底層130及III族化合物 半導體層100的半導體發光元件（LC)。 -31 - 201204881 如前所述，在本實施形態，使用由單晶之藍寶石錠30 切出的特定厚度的藍寶石單晶基板110，於該被成膜面， 良好地進行ΠΙ族化合物半導體層之外延成長。接著，具 有這樣的藍寶石單晶基板110與III族化合物半導體層 100的半導體發光元件（LC)，在發光特性、電氣特性上是 良好的。 [實施例] 以下，根據實施例進而詳細說明本發明。但是，本發 明，只要不超出其要旨的內容，並不限定於以下之實施例 (實施例1) 使用於實施形態說明的單晶提拉裝置1(參照圖1 )，製 作了藍寶石錠30。 首先，做爲準備步驟，於銥（1〇之坩鍋15投入高純度 之氧化鋁原料（Na濃度=5ppm)，使絕熱容器1 1減壓至 0.1 Pa ° 其後，作爲圖3所示之在固相的加熱步驟，藉由對加 熱線圈16供給高頻電流，於未達氧化鋁的融點（2050°C)的 溫度之1 7001，加熱保持2個小時（步驟101)。 其後，作爲圖3所示之融溶步驟，把坩鍋15的溫度 提高到2l〇〇t，使氧化鋁融溶，成爲氧化鋁融液35(步驟 1 02) ° -32- 201204881 接著，作爲圖3所示之在液相的加熱步驟，把增鍋j 5 之溫度在2l5〇°C維持4個小時，同時使坩鍋15下部的溫 度對2150°C提高20°C促進對流（步驟103)。 其後，作爲圖3之播種步驟，把坦鍋15的溫度降低 至205 以下，使絕熱容器11的壓力上升至大氣壓，在 供給氮氣的狀態下開始藍寶石錠3 0的提拉（步，驟〗〇4)。 形成肩部32(步驟105)，形成直徑約loomm的直胴部 33(步驟106)，製作長度約20cm的藍寶石錠30。 由單晶提拉裝置I，取出藍寶石錠30，在12〇〇-C熱處 理4個小時（退火），除去藍寶石錠30之熱應變。 由藍寶石錠30切出厚度約1mm之板，硏磨表面、背 面，得到厚度約900 μιη之藍寶石單晶基板1 1〇。 接著，以光學顯微鏡觀察有無氣泡。此外，藉由電暈 放電質量分析（GD-MS)法，分析藍寶石單晶基板11〇中的 不純物。 圖5顯示實施例1〜3及比較例1〜3之在固相的加熱 步驟及在液相的加熱步驟之溫度與時間以及評價結果。 評價結果，爲光學顯微鏡觀察之氣泡的有無、藉由 GD-MS法分析的藍寶石單晶基板110中的Na、V、Ba濃 度，使用藍寶石單晶基板110製作的半導體發光元件（LC) 的特性。又，半導體發光元件（LC)的特性，爲發光強度 Po(mW)、順方向電流20mA之順方向電壓VF(V)、逆方向 電壓20V之逆方向電流ΐι·(μΑ)。 此處，發光強度Ρο越大，順方向電壓VF越小，逆方 -33- 201204881 向電流Ir越小的話，半導體發光元件（LC)的特性越好。 又，在根據光學顯微鏡之觀察，要發現細微的氣泡（ 例如，未滿是困難的。 實施例1〜3及比較例1〜3之藍寶石單晶基板110的 直徑爲1 〇〇mm。 又，實施例1〜3及比較例1〜3之半導體發光元件 (LC)，係以實施形態記載的條件來製作，具有相同的形狀 。接著，半導體發光元件（LC)的特性，係由半導體發光元 件（LC)被形成的晶圓面，均等取出20個半導體發光元件 (LC)而測定的特性之平均値。 實施例1〜3及比較例1〜3之半導體發光元件（LC)之 發光的中心波長λί!爲450mm。 在實施例1，氣泡未被觀察到，容易發生結晶缺陷的 金屬不純物之Na爲 0.3ppm、V與Ba爲檢測極限的 0.1 ppm以下之低濃度。 接著，在實施例1，反映未觀測到氣泡，Na、V、Ba 之濃度很低，亦即結晶缺陷很少，半導體發光元件（LC)的 特性，爲發光輸出 Po = 20mW、VF(20mA) = 3.1V、 ΐΓ(2〇ν) = ΟμΑ，爲良好。 實施例2，係使在固相的加熱溫度爲2000°C下實施2 個小時，使在液相的加熱溫度爲2 1 00°C下實施4個小時。 氣泡未被觀察到，容易發生結晶缺陷的金屬不純物之Na 爲0.6ppm、V與Ba爲檢測極限的O.lppm以下之低濃度。 半導體發光元件（LC)的特性，爲發光輸出Po = 20mW、 -34- 201204881 VF(20mA) = 3.1V、ΐΓ(2〇ν) = ΟμΑ，爲良好。 實施例3，係沒有在固相的加熱步驟，使在液相的加 熱步驟變更爲溫度2080 °C下4個小時。氣泡未被觀察到， 容易發生結晶缺陷的金屬不純物之Na爲0.9ppm、V與Ba 爲檢測極限的0.1 PPm以下之低濃度。半導體發光元件 (LC)的特性，爲發光輸出 p〇 = 20mW、VF(20mA) = 3.1V、 Ir(20V) = l μΑ，爲良好。 另一方面，比較例1，未設在固相的加熱步驟以及在 液相的加熱步驟。氣泡被觀察到，容易發生結晶缺陷的金 屬不純物之Na爲3ppm、V爲0.5ppm，Ba爲0.4ppm。半 導體發光元件（LC)的特性，爲發光輸出 Po=15mW、 VF(20mA) = 3 ·3 V、I r (2 0 V) = 4 μ A，與實施例 1〜3 相比爲差 的結果》 此外，比較例2，使在固相的加熱步驟之條件變更爲 1 100°C下2個小時。未設在液相的加熱步驟。氣泡被觀察 到，容易發生結晶缺陷的金屬不純物之Na爲2ppm、V爲 0.2ppm，Ba爲〇.4ppm。半導體發光元件（LC)的特性，爲 發光輸出 Po=16mW、VF(20mA) = 3.2 V > Ιτ(2〇ν) = 3μΑ « 與 實施例1〜3相比爲差的結果。 比較例3，係沒有在固相的加熱步驟，使在液相的加 熱步驟條件變更爲溫度2060°C下4個小時。氣泡被觀察到 ，容易發生結晶缺陷的金屬不純物之Na爲1 .3ppm、V與 Ba爲檢測極限的0.1 ppm以下之低濃度。半導體發光元件 (LC)的特性，爲發光輸出 Po = 18mW、VF(20mA) = 3.2V、 -35- 201204881 ΐΓ(2〇ν) = 2μΑ，與實施例1〜3相比爲差的結果。 如圖5總結顯示，在實施例1〜3，未被觀測到氣泡， Na、V、Ba的濃度很低，半導體發光元件（LC)的特性也爲 良好。 相對於此，在比較例1〜3，觀察到氣泡的發生，同時 Na、V、Ba的濃度也比實施例1〜3爲高。此外，半導體 發光元件（LC)與實施例1〜3相比，發光輸出Po也低，逆 向電流Ir也變高。 如以上所說明的，藍寶石單晶基板1 1 〇所見之氣泡， 係起因於所含有的不純物之Na、V、Ba之氧化物等的金 屬化合物而產生的。接著，作爲這些不純物所含有的金屬 化合物的濃度，可以藉由在提拉藍寶石錠30之前，設置 在未達原料之氧化鋁的融點的溫度下加熱的在固相之加熱 步驟，與在融點以上的溫度進行加熱的在液相之加熱步驟 而減少。 又，不設在固相之加熱步驟，僅使用在液相之加熱步 驟亦可。 藉此，由於抑制藍寶石單晶基板1 1 0之結晶缺陷及氣 泡的發生，提高了被形成於藍寶石單晶基板110的半導體 發光元件（LC)的特性。 【圖式簡單說明】 圖1係說明單晶提拉裝置之一例之圖》 圖2係使用圖1所示之單晶提拉裝置所製造之藍寶石 -36- 201204881 錠之構成之一例。 圖3係供說明使用圖1所示之單晶提拉裝置，製造圖 2所示之藍寶石錠的步驟之流程圖。 圖4係說明本實施形態製造的半導體發光元件之一例 之圖。 圖5顯示實施例1〜3及比較例1〜3之在固相的加熱 步驟及在液相的加熱步驟之溫度與時間以及評價結果。 【主要元件符號說明】 1 〇 :加熱爐 1 1 :絕熱容器 1 2 :氣體供給管 1 3 :氣體排出管 1 4 :真空室 1 5 :坩堝 1 6 :加熱線圈 17 :提拉棒 19 :驅動部 3 〇 :藍寶石淀（ingot) 3 1 :種晶 32 :肩部 33 :直胴部 34 :尾部 35 :氧化鋁融液 -37- 201204881 100 : III族化合物半導體層 1 1 0 :基板 1 2 0 :中間層 130 :下底層 140 : η型半導體層 1 50 :發光層 160 : ρ型半導體層 1 7 0 :透明正極 180:正極焊墊（bondingpad) 190 :負極 I :單晶提拉裝置 LC :半導體發光元件 -38The decomposition temperature of Na20 is 1 950 ° C, the boiling point of BaO is 2000 ° C, and the decomposition temperature of V205 is 1750 ° C. Therefore, by heating at a high temperature, these metal oxides can be decomposed or volatilized before the sapphire ingot 30 is grown, and the bubbles and metals entering the sapphire ingot 30 can be suppressed. On the other hand, sodium chloride (NaCl) which is a Na source may be mixed with raw materials by the environment or the operator. The melting point of NaCl is 80 1 ° C and the boiling point is 14131. Mainly, by heating in a solid phase state before the raw material is melted and evaporating, it is possible to suppress the take-in of the sapphire ingot 30. In addition to the method, it is also effective to carry out the purification or pretreatment of the raw material alumina, to improve the purity of the heat insulating material of the heat insulating container 11, to purify the atmosphere in the vacuum chamber 14, and the like, and to prevent the incorporation of impurities. The heating temperature in the case where the alumina is heated in the solid phase state, most -13,04400,881 is the temperature at which the above three metal oxides begin to decompose or evaporate. Considering that the evaporation of NaCl under reduced pressure is at least 1,200. Above °C, preferably above 1 750 °C. In the case of solid phase, it is preferred that the melting point of the alumina is not reached (2 050 ° C), preferably less than 2000 ° C, and more suitable is less than 1 800 ° C. When heating is carried out in a solid phase, there is an advantage that the decomposed product and the evaporated product are easily released into the atmosphere. As a result, it has been found that the concentration of impurities in the sapphire single crystal substrate 11 (see Fig. 4 to be described later) is reduced, and the bubbles in the sapphire single crystal substrate 110 can be reduced. Even a fine bubble is considered to affect the film quality of the group III compound semiconductor layer 100 (see Fig. 4 which will be described later) which is epitaxially grown on the sapphire single crystal substrate 110. By these methods, the Na concentration in the large-diameter sapphire ingot 30 can be reduced, and the development of a high-purity sapphire single crystal of less than 1 ppm can be stably achieved. Further, by tailoring the conditions, a Na concentration of less than 0.5 ppm was achieved. <Step of Manufacturing Sapphire Ingot 30> Fig. 3 is a flow chart for explaining the steps of manufacturing the sapphire ingot 30 shown in Fig. 2 by using the single crystal pulling device 1 shown in Fig. 1. In the manufacture of the sapphire ingot 30, first, the solid alumina which is filled in the crucible 15 in the heating furnace 1 is heated and held at a temperature not reached to the melting point (2050 ° C). The step of heating in the solid phase (step 101). Next, 'the melting step of melting the alumina in the crucible 15 is performed (step 102). -14- 201204881 Next, the temperature is continued at a higher temperature than the melting point of the alumina. Heating (baking) to maintain the liquid phase heating step (step 103) ° Next, the lower end of the seed crystal 31 is brought into contact with the oxidized melt, that is, the alumina melt 3 5 (step 1 04) ° The state 'executing a shoulder forming step of forming the shoulder 32 below the seed crystal 31 by rotating the seed crystal 3 1 while pulling upward (step 1〇 5) » Next, contacting the lower end portion of the shoulder 32 In the state of oxidizing the melt 35, a straight portion forming step of forming a straight portion (ankle portion) 33 below the shoulder portion 32 is performed as the seed crystal 31 is rotated while the shoulder portion 32 is rotated. Step forming step) (step 1〇6). The lower end portion of the portion 33 is in contact with the alumina melt 35, and the straight portion 33 is rotated while passing through the seed crystal 31 and the shoulder portion 3, and pulled upward by the alumina melt 35. The tail portion forming step of the tail portion 34 is formed below the straight portion 33 (step 107). Thereafter, after the obtained sapphire ingot 30 is cooled, it is taken out to the outside of the heating furnace 10, and the series of manufacturing steps is completed. Then, the heat treatment of the sapphire ingot 30 is performed to alleviate the strain due to the temperature distribution in the ingot. For example, if the sapphire ingot 30 has a diameter of 100 mm, it is carried out for 3 hours at 1,200 ° C or higher, preferably 1 The heat treatment is carried out under conditions of 500 ° C or more for 5 hours or more. The heating/cooling rate is 1.0 ° C / min to 10.0 ° C / min, preferably 2.0 ° 〇 / min ~ 7.0 ° (1; / min. When the diameter (size) of the sapphire single crystal substrate 1 10 (refer to FIG. 4 described later) is increased, for example, when the diameter is 150 mm, the condition that the temperature is raised to -15-201204881 and the time is elongated becomes an appropriate range. Secondly, the sapphire ingot obtained in this way 30, firstly, at the boundary between the shoulder portion 32 and the straight portion 33 and at the boundary between the straight portion 33 and the tail portion 34, the straight portion 33 is cut out. Next, the straight portion 33 is cut out, and for example, The double-wire saw is cut in a direction orthogonal to the longitudinal direction of the sapphire ingot 30, and the surface is honed to form a sapphire single crystal substrate 110. In this case, the sapphire ingot 30 of the present embodiment is grown in a crystal. Since the sapphire single crystal has a c-axis direction, the main surface of the obtained sapphire single crystal substrate 110 is a C-plane ((0001) plane) of a sapphire single crystal. Further, depending on the growth conditions of the compound semiconductor layer, the main surface of the substrate may be processed by adding an off angle to the C surface. In addition, it can be cut out outside the C surface. Next, each step described above will be specifically described. However, the preparation steps performed before the heating step of the solid phase in step 1 〇 1 are described in the following. (Preparation step) In the preparation step, first, the seed crystal 31' is placed on the holding member 18 of the pulling rod 17 at a specific position. At this time, the C-plane ((0001) plane) of the sapphire is exposed at the lower end of the seed crystal 31. Next, in the crucible 15 塡 氧 铭 铭 铭 铭 ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装 组装The Na concentration in the alumina of the raw material is about 1 to 1 〇 PPm. Further, in order to increase the purity to less than 1 ppm, it is necessary to adopt a high-order technique such as refining treatment, which results in a decrease in productivity and an increase in raw material cost. In addition, the work environment and the improvement of the working methods that are thoroughly subjected to the Na pollution countermeasures will also lead to a decrease in productivity. On the other hand, the V and Ba in the raw material are low concentrations of less than 1 ppm, but the concentration may vary depending on the manufacturer and the date of manufacture. Then, the gas supplied from the gas supply unit 21 is not supplied. In the state, the inside of the heat insulating container 1 1 is decompressed using the exhaust portion 24. At this time, the inside of the heat insulating container 11 is decompressed to IPa or less, preferably 10'3Pa or less, and more preferably 1〇·5Ρ& (In the heating step of the ® phase) Next, the alumina solidified in the crucible 15 is heated (baked) at a temperature of 1200 ° C or higher and less than the melting point of alumina (2050 ° C). . That is, the alumina does not melt and becomes a solid phase heating. When the temperature of the heating exceeds 1 800 °C, the powder of the alumina or the crystal piece of the raw material of the sapphire ingot 30 is fused to each other, thereby inhibiting decomposition of the metal compound and volatilization of the metal compound. Therefore, the heating temperature is preferably 1 200 ° C or more and less than 1800 ° C. Further, in the heating step of the solid phase, heating is started from the lowermost end of the crucible 15 of the alumina in which the raw material is filled, and it is preferable to sequentially heat the alumina of the raw material from the lower side of the crucible 5 to the upper side. . Therefore, it is preferable to promote the volatilization of a metal such as NaCl or a metal compound obtained by decomposing a metal compound such as oxygen or the like. -17- 201204881 The heating of the crucible 1 5 is performed by supplying a high-frequency alternating current (referred to as a high-frequency current in the following description) to the heating coil 16 by the coil power supply 25 . When the high-frequency current is supplied to the heating coil 16 by the coil power supply 25, the magnetic flux around the heating line 圏16 is repeatedly generated/destroyed. Then, when the magnetic flux generated by the heating coil 16 crosses the crucible 15 through the heat insulating container 11, a magnetic field which hinders the change of the magnetic field is generated on the wall surface of the crucible 15, thereby generating an eddy current in the crucible 15. Next, the crucible 15 generates the Joule heat (W = I2R) proportional to the surface resistance (R) of the crucible 15 by the eddy current (I), and the crucible 15 is heated. The crucible 15 is heated, and the alumina contained in the crucible 15 is also heated. Then, when the heating is performed upward from the lower side of the crucible 15, the coil driving unit 28 moves the center position of the heating coil 16 in the vertical direction to the lower end portion of the crucible 15, and the coil power supply 25 heats the pair. The coil 16 is energized to start the induction heating of the crucible 15 and the heating coil 16 is gradually moved upward by the coil driving portion 28'. Further, the crucible 15 is heated in a portion adjacent to the heating coil 16. However, the temperature of the entire crucible 15 is gradually increased by heat conduction. In the heating step of the solid phase, at least one hour or more is preferably performed. More than 2 hours. In view of the productivity, it is preferable that the gas in the heat insulating container 11 is maintained in a reduced pressure state in order to promote the volatilization of a gas such as metal or oxygen which is obtained by decomposing the metal compound and the metal compound. In addition, it is preferred to use an inert gas. -18- 201204881 (melting step) Next, the alumina in the crucible 15 is completely melted to become a silver oxide melt 35. It is preferable to melt the aluminum oxide from the lowermost end of the crucible 15 of the alumina filled with the raw material, and to melt the aluminum oxide of the raw material sequentially from the lower side of the crucible 15 to the upper side. Here, after the heating step of the solid phase is completed, when the coil driving unit 2 8 moves the center position of the heating coil 16 in the vertical direction to the lower end portion of the crucible 15, the aluminum is completely melted. The current for the temperature is supplied to the heating coil 16 by the coil power source 25, and the heating coil 16 is gradually moved upward by the coil driving portion 28, thereby promoting the decomposition of the metal compound and the metal compound. Volatilization of gases such as metals and oxygen. At this time, when the alumina is rapidly melted, the metal or the gas obtained by decomposing the metal compound and the metal compound is left in the alumina melt 35 before being discharged. Therefore, it takes at least 3 hours or more until the alumina of the raw material is completely melted, and it is preferable to spend 10 hours or more. Further, in the melting step, in order to promote the volatilization of a metal or oxygen gas obtained by decomposing the metal compound and the metal compound, it is preferable to maintain the reduced pressure in the heat insulating container 11. In addition, it is preferred to use an inert gas. (Step of heating in the liquid phase) Next, the alumina melt 35 is maintained at a higher melting point than the alumina -19-201204881 3 0 ° C to 3 00 ° C temperature. When the heating temperature is lower than this temperature range, the decomposition product and the bubble are not easily detached, and it is not effective under the treatment for several hours, and heating is required for a long time, so the productivity is remarkably low. On the other hand, when the heating temperature is higher than this temperature range, the damage of the heating furnace 10 such as the crucible 15 and the heat insulating container 11 becomes large, and there is a limit on the apparatus. At this time, the alumina of the raw material is melted into a liquid phase. The hold time is, for example, 2 to 20 hours. Further, in the heating step of the liquid phase, in order to promote the volatilization of the metal, oxygen or the like obtained by decomposing the metal compound and the metal compound, it is preferable to maintain the reduced pressure in the heat insulating container 11. In addition, it is preferred to use an inert gas. Further, the temperature and time of the heating step of the solid phase and the heating step of the liquid phase are as long as the material of the crucible 15 containing the alumina of the raw material and the powder of the alumina of the raw material or the metal of the impurity contained in the crystal piece It is sufficient to change the concentration of the compound. (Shoulder forming step) In the shoulder forming step, the gas supply unit 21 supplies the mixed gas in which the oxygen source and the nitrogen gas are mixed at a specific ratio using the 02 source 22 and the N2 source 23, to the inside of the heat insulating container 11. However, in the shoulder forming step, as will be described in detail later, it is not necessary to supply a mixed gas of oxygen and nitrogen, for example, only nitrogen may be supplied. Further, the coil power supply 25 then supplies a high-frequency current to the heating coil 16 through the 坩埚1. 5 Heat the alumina melt 3 5 . -20-201204881 Further, the pulling drive unit 19 lowers the pulling rod 17 and stops the lower end of the seed crystal 31 attached to the holding member 18 at a position in contact with the aluminum melt 35 in the crucible 15, and then lifts it. The rod 17 is pulled at the first pulling speed. Further, the rotation driving unit 20 rotates the pulling rod 17 at the first rotation speed. As a result, the seed crystal 31 is rotated while being immersed in the alumina melt 35 at its lower end portion, and a shoulder portion 32 which is expanded toward the lower side of the seed crystal 31 is formed at the lower end of the seed crystal 31. Further, in the case of producing a sapphire ingot 30 for obtaining a so-called 4 inch (100 mm diameter) wafer, the shoulder forming step is ended when the diameter of the shoulder portion 32 is almost 120 mm. Bubbles, the larger the diameter, the easier it is to take in. (Direct straight portion forming step) In the straight portion forming step, the gas supply unit 21 mixes oxygen and nitrogen at a specific ratio using the 〇2 source 22 and the N2 source 23, and sets the oxygen concentration to a range of 0.6% or more and 3.0% or less. The mixed gas is supplied into the heat insulating container 1 1. Further, the coil power supply 25 then supplies a high-frequency current to the heating coil 16, and heats the alumina melt 35 through the crucible 15. Further, the pulling drive unit 19 pulls up the pulling rod 17 at the second pulling speed. Here, the second pulling speed may be the same speed as the first pulling speed of the shoulder forming step, or may be a different speed. Further, in addition, the rotation driving unit 20 rotates the pulling rod 17 at the second rotation speed. Here, the second rotation speed may be the same speed as the first rotation speed of the shoulder forming step, or may be a different speed ′′ and the shoulder 3 2 of the seed crystal 3 1 , at the lower end portion thereof. The state in which the alumina melt 35 is immersed is rotated while being pulled up. Therefore, at the lower end portion of the shoulder portion 32, a cylindrical straight portion 33 is preferably formed. The diameter of the straight portion 33 may be larger than a specific diameter. Further, in the straight portion forming step, the lower end portion of the straight portion 33 which is vertically upward is pulled up and maintained in contact with the alumina melt 35. (Tail Formation Step) In the tail forming step, the gas supply portion 21 mixes oxygen and nitrogen in a specific ratio using the 02 source 22 and the N2 source 23, and sets the oxygen concentration to a higher mixed gas than the straight portion forming step. It is supplied into the heat insulating container 11. However, the oxygen concentration in the mixed gas in the tail forming step is set to be in the range of 1.0% or more and 5.0% or less. Further, the coil power supply 25 then supplies the high frequency current to the heating coil 16, and heats the alumina melt through the crucible 15 5 . . Further, the pulling drive unit 19 lifts the pulling rod 17 at the third pulling speed. Here, the third pulling speed ' may be the same speed as the first pulling speed of the shoulder forming step or the second pulling speed of the straight portion forming step, or may be a speed different from these. Further, the rotation driving unit 20 rotates the pulling rod 17 at the third rotation speed. Here, the third rotation speed may be the same as the second rotation speed of the shoulder forming step -22-201204881 or the second rotation speed of the straight portion forming step, or may be a speed different from these. Further, at the end of the tail forming step, the lower end of the tail portion 34 is maintained in contact with the alumina melt 35. Then, 'the final stage of the tail forming step after a predetermined period of time, the pulling speed of the pulling rod 17 is increased by the pulling drive portion 19, so that the pulling rod 17 is further pulled upward, and the lower end of the tail portion 34 is separated. The alumina melt 35» thereby obtains the sapphire ingot 30» shown in Fig. 2. Further, in the present embodiment, a mixed gas of oxygen and nitrogen is used, but not limited thereto, for example, mixed oxygen is used as the inactive An example of a gas may be argon. Further, in the present embodiment, the heating of the crucible 15 is performed by using an electromagnetic induction heating method. However, it is not limited thereto, and for example, a resistance heating method may be employed. In the case of the resistance heating method in which the crucible 15 is rotated, it is preferable to rotate the crucible 15 for stirring in each heating step. The sapphire single crystal substrate 110 as described above was produced from the sapphire ingot 30 manufactured as described above. The sapphire single crystal substrate 110 was visually observed for the presence or absence of bubbles by an optical microscope to determine the presence or absence of bubbles. At this time, the observed bubble size is 1 μm or more. Further, when the surface of the sapphire single crystal substrate 110 is used as a semiconductor light-emitting device (LC), it is preferable to apply smoothing or uneven processing in order to improve the crystallinity of the compound semiconductor layer and to improve the light-emitting efficiency. Further, the step of cutting the sapphire ingot 30' produced as described above in the direction orthogonal to the longitudinal direction of the sapphire ingot-23-201204881 30 and the step of honing the surface, cracking, cracking, etc. Less, with good processing yield <Semiconductor light-emitting device (LC)> Next, a semiconductor light-emitting device (LC) manufactured by using the sapphire single crystal substrate 110 manufactured by the above-described method for producing a sapphire ingot 30 will be described. In the semiconductor light-emitting device (LC), a group III compound semiconductor layer is formed on a sapphire single crystal substrate 110 having a diameter of about 100 mm and a thickness of about 900 μm (see FIG. 4 described later), and then a group III compound is formed. The back surface of the sapphire single crystal substrate 11 of the semiconductor layer is diced to a predetermined thickness, and after being subjected to a lapping process, it is cut into the size of the wafer. Next, a configuration of a semiconductor light-emitting device (LC) manufactured by the method of manufacturing a semiconductor light-emitting device (LC) to which the present embodiment is applied will be described. The semiconductor light-emitting device (LC) manufactured in the present embodiment has a sapphire single crystal substrate 110 and a compound semiconductor layer formed on the substrate. Examples of the compound semiconductor constituting the compound semiconductor layer include a group III-V compound semiconductor, a π-νι compound semiconductor, and a group IV-IV compound semiconductor. In the present embodiment, a group III-V compound semiconductor is preferred, and an in-group nitride semiconductor is preferred. Hereinafter, a semiconductor light-emitting device (LC) having a compound semiconductor layer composed of a group III nitride compound semiconductor will be described as an example. 24 - 201204881 Fig. 4 is a view showing an example of a semiconductor light-emitting device (LC) manufactured in the present embodiment. As shown in FIG. 4, a semiconductor light emitting element (LC) has a lower underlayer 130 and a group III compound semiconductor layer 1 on an intermediate layer 120 formed on a sapphire single crystal substrate 110. The group 111 compound semiconductor layer 1 is sequentially laminated with the n-type semiconductor layer 140, the light-emitting layer 150, and the p-type semiconductor layer 160. It is preferable to process the surface of the sapphire single crystal substrate 110 on which the semiconductor layer is formed by arranging a plurality of fine convex shapes because of the effect of improving the light-emitting output. Further, a transparent positive electrode 170 is laminated on the Ρ-type semiconductor layer 160, a positive electrode pad 180 is formed thereon, and a negative electrode is laminated on the exposed region 140c of the n-type contact layer 140a formed in the n-type semiconductor layer 140. 190° Here, the n-type semiconductor layer 140 formed on the lower underlayer 130 has an n-type contact layer 140a and an n-type clad layer 140b. The light-emitting layer 150 has a structure in which the barrier layer 150a and the well layer 150b are alternately laminated, and the p-type semiconductor layer 160 is laminated. The p-type cladding layer 16 0a and the p-type contact layer 16 Ob 0 are laminated in this embodiment. The total thickness of the compound semiconductor layer (the layer in which the intermediate layer 120, the lower underlayer 130, and the group III compound semiconductor layer 1 are bonded together) on the sapphire single crystal substrate 110 is preferably 3 μm or more, and more preferably 5 μηι or more, and more preferably 8 μιη or more. Further, it is preferable that the total thickness of these is preferably 1 5 μm or less. Next, the materials constituting the respective layers of the semiconductor light-emitting device (LC) will be described. -25-201204881 (intermediate layer 120) In the present embodiment, when the group III compound semiconductor layer 100 is formed by an organometallic chemical vapor phase growth method (mocvd), it is preferable to provide the intermediate layer 120 which functions as a buffering layer in sapphire single crystal. On the substrate 110. In particular, the intermediate layer 120 has a single crystal structure and is preferable from the viewpoint of the buffer function. When the intermediate layer 120 having a single crystal structure is formed on the sapphire single crystal substrate 110, the buffer function of the intermediate layer 120 functions effectively, so that the underlayer 130 and the group III compound semiconductor layer are formed on the intermediate layer 120. 100, a crystalline film having good orientation and crystallinity. The intermediate layer 120 is preferably made of aluminum, preferably aluminum nitride containing a group III nitride. The material constituting the intermediate layer 190 is not particularly limited as long as it is a bismuth nitride compound semiconductor represented by a general formula of AlGalnN (aluminum gallium nitride). Further, the group V may contain arsenic or phosphorus. When the intermediate layer 120 contains a composition of aluminum, aluminum gallium nitride (AlGaN) is preferred, and among the lanthanum elements, the composition of aluminum is preferably 50% or more. (Lower Underlayer 130) As the material used for the lower underlayer 130, a group III-containing nitride (GaN-based compound semiconductor) containing gallium is used, and in particular, AlGaN or GaN can be suitably used. The film thickness of the lower substrate 130 is preferably 0.1 μm or more, more preferably 〇.5 μηι or more, and still more preferably Ιμηη or more. (n-type semiconductor layer 140) -26-201204881 The n-type semiconductor layer 140 is composed of an n-type contact layer 140a and an n-type clad layer 140b. As the n-type contact layer 140a, a GaN-based compound semiconductor is used similarly to the lower underlayer 130. Further, the gallium nitride-based compound semiconductor constituting the lower underlayer 130 and the n-type contact layer 140a is preferably the same composition, and the total film thickness is set in the range of Ο.ίμηι~20μΓη, preferably 0.5μηι 1515ηηι, and further More preferably, it is set in the range of Ιμηι~12μιη. Since the n-type contact layer 140a has a current to flow, the thin field resistance becomes high and the electrical characteristics are not good. In addition, in thick occasions, the growth time and material cost increase, which is not good in terms of productivity and cost. The n-type cladding layer 140b can be formed by AlGaN, GaN, GalnN or the like. Further, an ultra-lattice structure which is a heterojunction or a plurality of layers of these structures may be used. In the case of using GalnN, it is preferable that the band gap of GalnN of the well layer 150b constituting the light-emitting layer 150 to be described later is larger. The film thickness of the n-type cladding layer 140b is preferably 5 nm to 500 nm, and more preferably 5 nm to 100 nm. (Light-emitting layer 150) The light-emitting layer 150 is a layer 150b composed of a barrier layer 150a composed of a gallium nitride-based compound semiconductor and a gallium nitride-based compound semiconductor containing indium, and is an n-type semiconductor. The layer 140 side and the p-type semiconductor layer 160 side are formed by laminating the barrier layers 150a in this order. In the present embodiment, the light-emitting layer 150 is alternately laminated with six layers of the barrier layer 150a and five layers of the well layer 150b. In the well layer 150b, as a gallium nitride-based compound semiconductor containing indium, for example, -27-201204881, Gai-sInsN (0) can be used. <s <0.4) and other gallium indium nitride. As the barrier layer 150a', a gallium nitride-based compound semiconductor such as AUGa^NiOScSO.S) having a well layer 1 5 Ob energy band gap energy composed of an indium-containing gallium nitride-based compound semiconductor can be suitably used. (P-type semiconductor layer 160) The p-type semiconductor layer 160 is composed of a p-type cladding layer 160a and a p-type contact layer 160b. As the p-type cladding layer 160a, AldGa1.dN (0) is preferable. <d^0.4) ° The film thickness of the p-type cladding layer 160a is preferably from 1 nm to 400 nm, more preferably from 5 nm to 10 nm. As the P-type contact layer 160b, at least AleGai_eN (0Se) may be mentioned. <0.5) A gallium nitride-based compound semiconductor layer. The film thickness of the p-type cladding layer 160b is not particularly limited, but is preferably 190 nm to 500 nm, more preferably 50 nm to 200 nm (transparent positive electrode 1 70). The material constituting the transparent positive electrode 170 is exemplified by ITO (for example). A previously known material such as In203-Sn〇2), ΑΖΟ(ΖηΟ-Α12〇3), ιζ〇(Ιη203-ΖηΟ), GZO(ZnO-Ga2〇3). Further, the structure of the transparent positive electrode ι7 没有 is not particularly limited, and a structure known in the past can be employed. The transparent positive electrode 170 may also be formed in a nearly uniform manner covering the p-type semiconductor layer 16', or may be formed in a lattice shape or a tree shape. (Positive Electrode Pad 180) -28- 201204881 The positive electrode pad 180 as an electrode formed on the transparent positive electrode 170 is made of, for example, a material such as gold, aluminum, nickel, or copper known in the prior art. The structure of the positive electrode pad 180 is not particularly limited, and a configuration known in the past can be employed. The thickness of the positive electrode pad 180 is in the range of 10 nm to 1,000 nm, preferably in the range of 300 nm to 500 nm. (Negative Electrode 1 90) As shown in FIG. 4, the negative electrode 190 is a group III compound semiconductor layer 100 (n-type semiconductor) which is formed on the intermediate layer 120 and the lower underlayer 130 which are formed on the sapphire single crystal substrate 110. The layer 140, the light-emitting layer 150, and the P-type semiconductor layer 16 0) are formed so as to be connected to the n-type contact layer 140a of the n-type semiconductor layer 140. Therefore, when the negative electrode 190 is formed, one of the p-type semiconductor layer 160, the light-emitting layer 150, and the n-type semiconductor layer 140 is removed, and the exposed region 140c of the n-type contact layer 140a is formed, and the negative electrode 190 is formed thereon. As the material of the negative electrode 190, the negative electrode of various compositions and structures is known, and these well-known negative electrodes can be used without any limitation, and can be provided by a conventional means widely known in the art. In the present embodiment, first, a gas containing a group V element is activated by a plasma on a sapphire single crystal substrate 110 to react with a metal material to form an intermediate layer 120 composed of a group III nitride. Next, the underlayer 130, the n-type semiconductor layer 140, the light-emitting layer 150, and the p-type semiconductor layer 160 are sequentially laminated on the intermediate layer 120 of the film formation. In the present embodiment, when the 111-group nitrogen-29-201204881 semiconductor semiconductor crystal is epitaxially grown on the sapphire single crystal substrate 1-10, the intermediate layer 120 is preferably formed by sputtering using a material which is activated by plasma activation. It is formed on the sapphire single crystal substrate 110. Here, the group V element is nitrogen, and the gas fraction of nitrogen in the gas when the intermediate layer 12 is formed is in the range of 50% to 99% or less. The intermediate layer 190 is formed into a single crystal structure. Thereby, the intermediate layer 120 having good crystallinity in a short time is formed as an alignment film having anisotropic properties on the sapphire single crystal substrate 1 1 〇. As a result, in the intermediate layer 120, a group III nitride compound semiconductor having good crystallinity can be grown as compared with the case where the intermediate layer 120 is not provided. In the present embodiment, after the intermediate layer 120 is formed by a sputtering method, the lower underlayer 130, the n-type semiconductor layer 140, and the light-emitting layer are preferably sequentially formed by an organic metal chemical vapor deposition (MOCVD) method. 150 and p-type semiconductor layer 160. In the MOCVD method, as the carrier gas, for example, hydrogen (HO or nitrogen) is used. As a gallium source of the steroid source, trimethylgallium (TMG), triethylgallium (TEG), or the like is used. Trimethylaluminum (ruthenium), triethylaluminum (TEA), etc. are used. As the indium source, trimethylindium (ruthenium), triethylindium (TEI), etc. are used. As a nitrogen source of the group V raw material, ammonia is used. (Nh3), hydrazine (N2H4), etc. As a dopant, a monodecane (SiH4) or a dioxane (Si2H6) is used as a ruthenium raw material. As a ruthenium raw material, decane gas (GeH4) can be used. An organic ruthenium compound such as tetramethylphosphonium (CHSHGe) or tetraethylphosphonium ((C2H5)4Ge). Further, the yttrium nitride-based compound semiconductor may contain other elements in addition to Al, Ga, and In, -30-201204881. For example, a doping element such as Ge, Si, Mg, Ca, Zn or Be may be mentioned. Further, it is not limited to an element to be intentionally added, and may include an impurity which is inevitably contained depending on film formation conditions, or a raw material or a reaction tube. A trace amount of impurities contained in the material. Further, after forming the lower underlayer 130 by MOCVD, it is formed by sputtering. Each of the n-type contact layer 140a and the n-type cladding layer 140b is formed by the MOCVD method, and then the p-type cladding layer 160a and the p-type contact layer constituting the P-type semiconductor layer 160 are formed by reactive sputtering. 1 60b i each layer may be formed on the sapphire single crystal substrate 110 having a diameter of 100 mm and a thickness of about 900 μm, and then the intermediate layer 120, the lower underlayer 130, and the group III compound semiconductor layer 1 are formed on the NMOS compound semiconductor layer 100. A transparent positive electrode 170 is laminated on the p-type semiconductor layer 160, and a positive electrode pad 180 is formed thereon. Further, a negative electrode 190 is formed on the exposed region 140c of the n-type semiconductor layer 140 formed on the n-type contact layer 140a. The sapphire single crystal substrate 110 on which the compound semiconductor layer is formed is formed, and then the sapphire single crystal substrate 1 1 is boring and honing (back surface) to a predetermined thickness. In the embodiment, the wafer is mounted on a commercially available boring machine (not shown), and the thickness of the sapphire single crystal substrate 110 of the wafer is reduced from, for example, about 900 μm to 120 μm by the boring step. treasure The wafer of the thickness of the single crystal substrate 1 1 is formed into a film of the intermediate layer 120, the lower underlayer 130, and the group III compound semiconductor layer 100 on the sapphire single crystal substrate 110, for example, by cutting into squares of 3 50 μm square. Semiconductor light-emitting device (LC) -31 - 201204881 As described above, in the present embodiment, the sapphire single crystal substrate 110 having a specific thickness cut out from the single crystal sapphire ingot 30 is used, and the film formation surface is satisfactorily The steroid semiconductor layer is grown outside. Then, the semiconductor light-emitting device (LC) having such a sapphire single crystal substrate 110 and a group III compound semiconductor layer 100 is excellent in light-emitting characteristics and electrical characteristics. [Examples] Hereinafter, the present invention will be described in detail based on examples. However, the present invention is not limited to the following examples (Example 1) The sapphire ingot 30 is produced by using the single crystal pulling apparatus 1 (see Fig. 1) described in the embodiment. First, as a preparation step, a high-purity alumina raw material (Na concentration = 5 ppm) is charged in a crucible 15 of 1 Torr, and the heat insulating container 1 1 is depressurized to 0.1 Pa °, and then it is shown in FIG. In the heating step of the solid phase, by supplying a high-frequency current to the heating coil 16, the temperature is maintained at 17001 which is less than the melting point of the alumina (2050 ° C) for 2 hours (step 101). Thereafter, As the melting step shown in FIG. 3, the temperature of the crucible 15 is raised to 2 l〇〇t, and the alumina is melted to become the alumina melt 35 (step 102) ° -32 - 201204881 Next, as FIG. 3 In the heating step shown in the liquid phase, the temperature of the booster j 5 is maintained at 21.5 ° C for 4 hours while the temperature of the lower portion of the crucible 15 is increased by 20 ° C to 2150 ° C to promote convection (step 103). Thereafter, as the seeding step of Fig. 3, the temperature of the pan 15 is lowered to 205 or less, the pressure of the heat insulating container 11 is raised to atmospheric pressure, and the pulling of the sapphire ingot 30 is started in the state where nitrogen gas is supplied (step, step) 〇4) Forming the shoulder 32 (step 105), forming a straight portion 33 having a diameter of about loomm (step 106), making a length of about 20 Cm sapphire ingot 30. From the single crystal pulling device I, the sapphire ingot 30 is taken out and heat treated at 12 〇〇-C for 4 hours (annealing) to remove the thermal strain of the sapphire ingot 30. The thickness is cut from the sapphire ingot 30 by about 1 mm. The sapphire single crystal substrate having a thickness of about 900 μm was obtained by honing the surface and the back surface. Next, the presence or absence of bubbles was observed by an optical microscope. Further, the sapphire was analyzed by the corona discharge mass spectrometry (GD-MS) method. The impurities in the single crystal substrate 11 are shown in Fig. 5. Fig. 5 shows the temperature and time of the heating step in the solid phase and the heating step in the liquid phase in Examples 1 to 3 and Comparative Examples 1 to 3, and the evaluation results. The presence or absence of bubbles observed by a microscope, the concentration of Na, V, and Ba in the sapphire single crystal substrate 110 analyzed by the GD-MS method, and the characteristics of a semiconductor light-emitting device (LC) produced using the sapphire single crystal substrate 110. The characteristics of the element (LC) are the luminous intensity Po (mW), the forward direction voltage VF (V) of the forward direction current of 20 mA, and the reverse direction current ΐι· (μΑ) of the reverse direction voltage of 20 V. Here, the larger the luminous intensity Ρο Forward direction The smaller the pressure VF is, the smaller the reverse current is -33-201204881, the better the characteristics of the semiconductor light-emitting element (LC). In addition, it is difficult to find fine bubbles according to the observation of the optical microscope (for example, it is difficult to be full). The sapphire single crystal substrate 110 of Examples 1 to 3 and Comparative Examples 1 to 3 has a diameter of 1 mm. Further, the semiconductor light-emitting elements (LC) of Examples 1 to 3 and Comparative Examples 1 to 3 are It is produced under the conditions described in the embodiments and has the same shape. Next, the characteristics of the semiconductor light-emitting device (LC) are the average characteristics of the characteristics measured by uniformly taking out 20 semiconductor light-emitting elements (LC) from the wafer surface on which the semiconductor light-emitting element (LC) is formed. The center wavelength λί! of the light-emitting of the semiconductor light-emitting device (LC) of Examples 1 to 3 and Comparative Examples 1 to 3 was 450 mm. In Example 1, the bubbles were not observed, and the Na of the metal impurities which are liable to cause crystal defects was 0.3 ppm, and V and Ba were low concentrations of 0.1 ppm or less of the detection limit. Next, in Example 1, it was reflected that no bubbles were observed, and the concentrations of Na, V, and Ba were low, that is, the crystal defects were few, and the characteristics of the semiconductor light-emitting element (LC) were the light-emitting output Po = 20 mW, VF (20 mA). = 3.1V, ΐΓ(2〇ν) = ΟμΑ, is good. In Example 2, the heating temperature of the solid phase was 2000 ° C for 2 hours, and the heating temperature of the liquid phase was 2 100 ° C for 4 hours. The bubbles were not observed, and the Na of the metal impurities which are prone to crystal defects was 0.6 ppm, and V and Ba were low concentrations of 0.1 ppm or less of the detection limit. The characteristics of the semiconductor light-emitting element (LC) are good for the light-emitting output Po = 20mW, -34-201204881 VF(20mA) = 3.1V, ΐΓ(2〇ν) = ΟμΑ. In Example 3, there was no heating step in the solid phase, and the heating step in the liquid phase was changed to a temperature of 2080 ° C for 4 hours. The bubbles were not observed, and the Na of the metal impurities which are prone to crystal defects was 0.9 ppm, and V and Ba were the low concentrations of 0.1 PPm or less of the detection limit. The characteristics of the semiconductor light-emitting element (LC) are good for the light-emitting output p〇 = 20mW, VF(20mA) = 3.1V, Ir(20V) = l μΑ. On the other hand, in Comparative Example 1, the heating step in the solid phase and the heating step in the liquid phase were not provided. As the bubbles were observed, the metal impurities which were prone to crystal defects had Na of 3 ppm, V of 0.5 ppm, and Ba of 0.4 ppm. The characteristics of the semiconductor light-emitting device (LC) are that the light-emitting output Po = 15 mW, VF (20 mA) = 3 · 3 V, and I r (2 0 V) = 4 μ A, which is inferior to the results of Examples 1 to 3. Further, in Comparative Example 2, the conditions of the heating step in the solid phase were changed to 1 100 ° C for 2 hours. A heating step not provided in the liquid phase. The bubbles were observed to have a Na of 2 ppm, a V of 0.2 ppm, and a Ba of 0.4 ppm of a metal impurity which is prone to crystal defects. The characteristics of the semiconductor light-emitting element (LC) were a light-emitting output Po = 16 mW, VF (20 mA) = 3.2 V > Ιτ(2〇ν) = 3μΑ « The result was poor compared with Examples 1 to 3. In Comparative Example 3, the heating step in the liquid phase was changed to a temperature of 2060 ° C for 4 hours without heating in the solid phase. The bubbles were observed, and the Na of the metal impurities which are prone to crystal defects is 1.3 ppm, and V and Ba are low concentrations of 0.1 ppm or less which are detection limits. The characteristics of the semiconductor light-emitting device (LC) were as follows: the light-emitting output Po = 18 mW, VF (20 mA) = 3.2 V, -35 - 201204881 ΐΓ (2 〇 ν) = 2 μΑ, which was inferior to Examples 1 to 3. As summarized in Fig. 5, in Examples 1 to 3, no bubbles were observed, and the concentrations of Na, V, and Ba were low, and the characteristics of the semiconductor light-emitting device (LC) were also good. On the other hand, in Comparative Examples 1 to 3, the occurrence of bubbles was observed, and the concentrations of Na, V, and Ba were also higher than those of Examples 1 to 3. Further, in the semiconductor light-emitting device (LC), compared with the first to third embodiments, the light-emission output Po is also low, and the reverse current Ir is also high. As described above, the bubbles observed in the sapphire single crystal substrate 11 1 are produced by a metal compound such as an oxide of Na, V or Ba contained in the impurities. Next, as the concentration of the metal compound contained in the impurities, the heating step in the solid phase can be performed by heating at a temperature at which the melting point of the alumina of the raw material is not reached before the sapphire ingot 30 is lifted. The temperature above the point is heated and the heating step in the liquid phase is reduced. Further, it is not provided in the heating step of the solid phase, and only the heating step in the liquid phase may be used. Thereby, the characteristics of the semiconductor light-emitting device (LC) formed on the sapphire single crystal substrate 110 are improved by suppressing the occurrence of crystal defects and bubbles in the sapphire single crystal substrate 110. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing an example of a single crystal pulling device. Fig. 2 is an example of a configuration of a sapphire-36-201204881 ingot manufactured by using the single crystal pulling device shown in Fig. 1. Fig. 3 is a flow chart for explaining the steps of manufacturing the sapphire ingot shown in Fig. 2 using the single crystal pulling apparatus shown in Fig. 1. Fig. 4 is a view showing an example of a semiconductor light emitting element manufactured in the present embodiment. Fig. 5 shows the temperature and time of the heating step in the solid phase and the heating step in the liquid phase and the evaluation results of Examples 1 to 3 and Comparative Examples 1 to 3. [Description of main component symbols] 1 〇: Heating furnace 1 1 : Insulation container 1 2 : Gas supply pipe 1 3 : Gas discharge pipe 1 4 : Vacuum chamber 1 5 : 坩埚 1 6 : Heating coil 17 : Lifting rod 19 : Driving Part 3 〇: sapphire (ingot) 3 1 : seed crystal 32: shoulder 33: straight 34 34 : tail 35 : alumina melt -37- 201204881 100 : group III compound semiconductor layer 1 1 0 : substrate 1 2 0: intermediate layer 130: lower underlayer 140: n-type semiconductor layer 150: light-emitting layer 160: p-type semiconductor layer 1 7 0: transparent positive electrode 180: positive bonding pad 190: negative electrode I: single crystal pulling device LC : Semiconductor Light Emitting Components - 38

Claims (1)

201204881 七、申請專利範圍： 1· 一種藍寶石單晶之製造方法，其特徵係包含： 於根據柴氏（Czochralski)長晶法之藍寶石單晶提拉裝 置， 將鈉（Na)濃度1 ppm以上之氧化鋁原料，在超過氧化 鋁的融點的溫度下，於坩鍋中以融溶的融液的狀態予以保 持之在液相的加熱步驟， 藉由使前述坩鍋中的附著於氧化鋁之前述融液的種晶 旋轉同時提拉，朝向該種晶的下方形成直徑變大的肩部的 肩部形成步驟，以及 藉由使附著於前述融液的前述肩部旋轉同時提拉，於 該肩部的下方形成圓柱狀的胴部之胴部形成步驟。 2.如申請專利範圍第1項之藍寶石單晶之製造方法， 其中前述在液相的加熱步驟，係於比氧化鋁的融點高30°C 以上30(TC以下的溫度在高溫下進行的》 3 .如申請專利範圍第1或2項之藍寶石單晶之製造方 法，其中前述在液相的加熱步驟之前述融液，係由前述坩 鍋的下部朝向上部’使該坩鍋中的氧化鋁原料融溶而形成 的。 4. 如申請專利範圍第1項之藍寶石單晶之製造方法， 其中前述在液相的加熱步驟之前’進而包含使前述坩鍋中 的氧化鋁原料，保持在未達氧化鋁的融點的溫度下之在固 相的加熱步驟。 5. 如申請專利範圍第4項之藍寶石單晶之製造方法， -39 - 201204881 其中前述在固相的加熱步驟，係：δ 2050°C的溫度下進行的。 6. 如申請專利範圍第4或5項之 法，其中前述在固相的加熱步驟之前 料，係由前述坩鍋的下部朝向上部昇 7. —種藍寶石單晶基板，其特徵 1項之藍寶石單晶之製造方法所製遼 及釩（V)之分別的濃度均未達ippm， 〇 8. —種藍寶石單晶基板，其特徵 4項之藍寶石單晶之製造方法所製造任 釩（V)之分別的濃度均未達lppm，而ϋ i 1200°C以上且未達 藍寶石單晶之製造方 述坩鍋中的氧化鋁原 溫。 係以申請專利範圍第 i 的，鈉（Na)、鋇（Ba) 而直徑在100mm以上 係以申請專利範圍第 J，鈉（Na)、鋇（Ba)及 [徑在100mm以上。 -40-201204881 VII. Patent application scope: 1. A method for manufacturing sapphire single crystal, characterized in that it comprises: a sodium (Na) concentration of 1 ppm or more in a sapphire single crystal pulling device according to the Czochralski crystal growth method. The alumina raw material is heated in the liquid phase in a state of being melted in a crucible at a temperature exceeding the melting point of the alumina, by adhering the alumina in the crucible to the alumina The seed crystal rotation of the melt is simultaneously pulled, a shoulder forming step of forming a shoulder having a larger diameter toward the lower side of the seed crystal, and the pulling of the shoulder portion attached to the melt is simultaneously pulled A crotch portion forming step of forming a cylindrical crotch portion below the shoulder portion. 2. The method for producing a sapphire single crystal according to claim 1, wherein the heating step in the liquid phase is performed at a temperature higher than a melting point of alumina by 30 ° C or more and 30 (a temperature lower than TC is performed at a high temperature) 3. The method for producing a sapphire single crystal according to claim 1 or 2, wherein the melt in the liquid phase heating step is oxidized in the crucible from a lower portion of the crucible toward the upper portion 4. The method for producing a sapphire single crystal according to the first aspect of the patent application, wherein the foregoing step of heating the liquid phase further comprises: maintaining the alumina raw material in the crucible. a heating step of the solid phase at a temperature at which the melting point of the alumina is reached. 5. A method for producing a sapphire single crystal according to item 4 of the patent application, -39 - 201204881 wherein the heating step in the solid phase is: δ 6. The method of claim 4 or 5, wherein the foregoing step of heating before the solid phase is carried out by the lower portion of the crucible toward the upper portion. 7. A sapphire single Crystal substrate The method for producing a sapphire single crystal according to the feature 1 has a concentration of less than ippm, and the sapphire single crystal substrate, which is characterized by four sapphire single crystals. The respective concentrations of vanadium (V) are not more than 1 ppm, and the original temperature of the alumina in the crucible is not more than 1200 ° C and the sapphire single crystal is not produced. Sodium (Na), barium (Ba) and a diameter of 100 mm or more are in the scope of patent application J, sodium (Na), barium (Ba) and [diameter is 100 mm or more. -40-
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