200849353 九、發明說明： t發明所屬之技術領域3 [技術領域] 本發明係關於將藍寶石基板表面積層有由氮化物半導 5 體層構成之光半導體層且形成有複數光元件的晶圓，沿著 可區劃該複數零件之界道而分割之晶圓的加工方法。 L先前技術3 [背景技術] 於製造發光二極體或雷射二極體等之光元件的製造步 10 驟中，將藍寶石基板表面以磊晶法積層有由氮化物半導體 層構成之光半導體層且形成將複數光元件形成矩陣狀之光 元件晶圓。如此形成之光元件晶圓，光元件被稱為界道 (street)之分割預定線區劃著，而沿著此界道分割以製造各 個光元件。沿著如此的光元件晶圓所進行之切斷，一般係 15 於研削藍寶石基板内面而形成預定完成厚度後，藉著可使 切削刀具高速旋轉以進行切削之切削裝置來進行。又，上 述沿著界道分割光元件晶圓的方法上，已有提出了研削藍 寶石基板内面而形成預定完成厚度後，沿著界道照射脈衝 雷射光線而形成雷射加工溝及/或變質層，並沿著此雷射 20 加工溝及/或變質層進行破斷的方法。（參照例如專利文獻 1、專利文獻2。） 專利文獻1 ··特開平10 — 305420號公報 專利文獻2 :特許第44902號公報 【發明内容3 5 200849353 [發明揭示] [發明欲解決的課題] —於研削藍寶石基板内面而形成厚度為 ’以下的厚度時，則外周部會向表面側翹起彎曲。此 料圓之f㈣可理解會發錢積層於藍寶石基板表 面的氮化物半導體層朝向中心、拉住之應力之故。 =此-來，—旦光元件晶圓f曲，則沿著界道照射雷 、、光日守，難以將雷射光線之聚光點定位於預定位置，而無 法施予預定的雷射加 工。 10 θ本發明係鑑於上述事實而完成的發明，主要的技術課 題在於提供能减光元件晶圓發生㈣而能進行加工之晶 圓加工方法。 為了解決上述主要的技術課題，依據本發明，提供一 種曰曰圓加工方法，係將於藍寶石基板表面積層有光半導體 5層且形成有複數光元件之晶圓，以沿著可區劃該複數光元 件之界道進行分割之晶圓加工方法，而該晶圓加工方法包 δ有光半導體層分離步驟，係沿著業經形成在晶圓表面 之忒界道照射對該光半導體層具有吸收性之波長的雷射光 線並/σ著该界道分離該光半導體層；保護構件裝設步驟， 2〇係將保護構件貼附於業經實施該光半導體層分離步驟之晶 圓表面，及，内面研削步驟，係研削業經貼附該保護構件 之晶圓内面並形成光碟之完成厚度。 [發明效果] 本發明所構成之晶圓加工方法，在實施光半導體層分 200849353 離步驟時’晶圓係在研削内面而形成光碟之完成厚度之前 的狀態，因此，外周部不會叙起彎曲，故能將雷射光線之 聚光點確實定位於光半導體層之預定位置。又，即使是實 施内面所削並將晶圓形成光碟之完成厚度，亦以實施上述 5光半導體層分離步驟而沿著界道分離光半導體層因此晶 圓之外周不會赵起。如此一來，可解除在後步驟中晶圓之 外周想起所造成之不良情形於未然。200849353 IX. Description of the Invention: Technical Field [Technical Field] The present invention relates to a wafer in which a surface layer of a sapphire substrate has an optical semiconductor layer composed of a nitride semiconductor layer and a plurality of optical elements are formed. A method of processing a wafer that can be divided by dividing the boundary of the plurality of parts. L. Prior Art 3 [Background Art] In the manufacturing step 10 of manufacturing an optical element such as a light-emitting diode or a laser diode, an optical semiconductor composed of a nitride semiconductor layer is laminated on the surface of a sapphire substrate by epitaxy A layer of optical element wafers in which a plurality of optical elements are formed in a matrix is formed. In the thus formed optical element wafer, the optical element is divided by a predetermined dividing line called a street, and is divided along the boundary to manufacture each optical element. The cutting along the optical element wafer is generally performed by grinding the inner surface of the sapphire substrate to form a predetermined thickness, and then performing the cutting by a high-speed rotation of the cutting tool. Further, in the method of dividing the optical element wafer along the boundary, it has been proposed to form a laser beam and irradiate the laser beam along the boundary to form a laser beam and/or deteriorate it by grinding the inner surface of the sapphire substrate to form a predetermined thickness. The layer and the method of breaking along the laser 20 processing groove and/or metamorphic layer. (Patent Document 1 and Patent Document 2) Patent Document 1 (Japanese Patent Application Laid-Open No. Hei No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. Publication No. - When the inner surface of the sapphire substrate is ground to form a thickness of 'below, the outer peripheral portion is warped toward the surface side. The f(4) of the material circle understands that the nitride semiconductor layer deposited on the surface of the sapphire substrate faces the center and is stressed. = This - come, - When the optical component wafer f is curved, it is difficult to illuminate the spot of the laser light at a predetermined position, and it is impossible to apply a predetermined laser processing. . 10 θ The present invention is an invention completed in view of the above facts, and a main technical subject is to provide a wafer processing method capable of performing processing by reducing the occurrence of light-reducing element wafers (4). In order to solve the above-mentioned main technical problems, according to the present invention, a rounding processing method is provided in which a wafer of a plurality of optical semiconductors is formed on a surface area of a sapphire substrate and a plurality of optical elements are formed to divide the plurality of light along the plurality of light elements. a wafer processing method for dividing a component, wherein the wafer processing method includes a photo-semiconductor layer separation step, which is absorptive to the photo-semiconductor layer along a boundary line formed on the surface of the wafer. a laser light of a wavelength and /σ separates the optical semiconductor layer by the boundary; a protective member mounting step of attaching the protective member to the surface of the wafer through which the photo-semiconductor layer is separated, and the inner surface is ground In the step of grinding, the inner surface of the wafer of the protective member is attached and the finished thickness of the optical disc is formed. [Effect of the Invention] In the wafer processing method of the present invention, when the photo-semiconductor layer is separated from the step 200849353, the wafer is in a state before the inner surface of the wafer is formed to form the finished thickness of the optical disc. Therefore, the outer peripheral portion does not warp. Therefore, the spot of the laser light can be surely positioned at a predetermined position of the photo-semiconductor layer. Further, even if the thickness of the wafer is cut and the finished thickness of the wafer is formed, the above-described 5-photo-semiconductor layer separation step is carried out to separate the photo-semiconductor layer along the boundary, so that the periphery of the wafer does not rise. In this way, it is possible to cancel the problem caused by the outer circumference of the wafer in the subsequent step.
【實施方式J[Embodiment J
[用以實施發明之最佳樣態] 1〇 ^參_加圖式更詳細說明本發賴構成之晶圓加 工方法。 第1圖顯示藉本發明所構成之晶圓加工方法可分割成 。们光7L件之Βθ圓即光元件晶圓之立體圖，第2圖顯示第工 圖所不之光7L件晶圓之重要部分放大剖面圖。第！圖及第2 圖所不之光7L件晶圓2,係以積層在藍寶石基板2味面之氮 化物半導體層所構成之光半導體層2卜複數光元件22形成 矩陣狀各光元件22以形成袼子狀(柵狀）之界道23而區劃 著又，監實石基板20形成例如700//m厚度。又，氮化物 半V體層所構成之光半導體層21係藉例如蠢晶法而形成在 20監寶石基板20表面。 若要沿著界道23來分割上述光元件晶圓2，首先，實施 沿著業經形成在光元件晶圓2表面之界道23照射對於光半 導體層21具有吸收性之波長的雷射光線，並分離光半導體 層21之光半導體層分離步驟。此光半導體層分離步驟係使 7 200849353 用第3圖所示之雷射加工裝置來實施。第3圖所示之雷射加 工裝置3包含有保持被加工物之工作吸盤3丨、可對已被保持 在該工作吸盤31上之被加工物照射雷射光線之雷射光線照 射機構32、可拍攝已被保持在工作吸盤31上之被加工物之 5攝像機構33。工作吸盤31係建構成可吸取保持被加工物， 且藉著未以圖式顯示之移動機構而使工作吸盤31朝向第3 圖中以箭頭X所示之加工移送方向及以箭頭γ所示之分度 移送方向移動。 上述雷射光線照射機構32包含有實質上配置成水平之 1〇圓筒狀殼體32卜殼體321内配設著未以圖式顯示之由YAG 雷射振盪器或YV04雷射振盪器所構成之脈衝雷射光線振 盪器，或具有反覆頻率設定機構之脈衝雷射光線振盪機 構。上述殼體321之前端部裝設有用以將脈衝雷射光線振盪 機構所振盪之脈衝雷射光線予以聚光之聚光器322。 15 裝設於構成上述雷射光線照射機構32之殼體321之前 端部的攝像機構33，除了於圖式之實施樣態中以可見光線 攝像之通常的攝像元件(CCD)外，更以對被加工物照射紅外 線的紅外線照明機構、可捕捉以該紅外線照明機構所照射 之紅外線的光學系統、可輸出已對應該光學系統所捕捉之 20紅外線之電信號的攝像元件（紅外線CCD)等所構成，並將所 拍攝之影像信號送至未以圖式顯示之控制機構。 在使用上述雷射加工裝置3實施光半導體層分離步驟 上，如第3圖所示將光元件晶圓2之内面載置於雷射加工裝 置3之工作吸盤31上。藉著未以圖式顯示之吸取機構而將光 200849353 元件晶圓2吸者保持於工 、作吸盤31上（晶圓保持步驟）。因 此，被保持在工作吸舷M v > T t 及邊31上之光元件晶圓2的表面2a呈上 側。 如上所述已吸取保持著光元件晶圓2之工作吸盤Μ藉 5著未以圖式顯示之加工移送機構而被朝向攝像機構33之: 下方移動。-旦工作吸盤31定位於攝像機構33正下方，則 藉著攝像機構33及未以圖式顯示之控制機構進行檢測光元 件晶圓2之應進行雷射加工之加工領域的對準作業。即，攝 像機構33及未以圖式顯示之控制機構執行用以使形成在光 H)元件晶圓2之預定方向之界道23,與沿著界道23照射雷射光 線之雷射光線照射機構32之聚光器322之對位(合對位置）， 即執行圖案匹配等影像處理，並遂行雷射光線照射位置之 對準。又，對於相對於形成在光元件晶圓2之上述預定方向 呈直角延伸之界道23亦遂行雷射光線照射位置之對準。 15 如上所述，檢測出已保持在工作吸盤31上之光元件晶 圓2的界道23，並進行了雷射光線照射位置之對準的話，則 如第4圖（a)所示將工作吸盤31朝向用以照射雷射光線之雷 射光線照射機構32之聚光器322所位處之雷射光線照射領 域移動，而將預定的界道23定位於聚光器322的正下方。此 20時，如第4圖⑷所示，光元件晶圓2之界道23之一端（如第4 圖（a)之左端）被定位在聚光器322之正下方位置。接著，一 面從雷射光線照射機構32之聚光器322照射對於光半導體 層21具有吸收性波長之脈衝雷射光線，而一面以預定加工 移送速度使工作吸盤31朝向第4圖（a)之箭頭X1所示方向移 9 200849353 動（光半導體層分離步驟）。如第4圖（b)所示當界道23之另 端（第4圖之右端）到達聚光器322的正下方位置 射光線之照射停止且停止工作吸盤31的移動。其結果，Z 第4圖（b)及第5圖所示，於形成在光元件晶圓2表面之光半導 5體層21形成雷射加工溝2U，光半導體層2丨沿著界道被分 離。於此半導體層分離步驟中，使脈衝雷射光線之聚光點^ 配合於光半導體層21之上面附近。實施此半導體層分離步 驟時，光元件晶圓2之厚度例如為700 ，因此外周部不會 翹起彎曲，故脈衝雷射光線之聚光點P可確實定位於光半導 10 體層21的上面附近。 又，上述半導體層分離步驟係例如在以下加工條件下 進行。 雷射光線之光源 :YAG雷射 波長 :355nm 反覆頻率 :100kHz 每一脈衝之能量密度 :15J/cm2 聚光點徑度 ：10 // m 加工移送速度 :200mm/秒 如此一來，若已沿著該延伸存在於光元件晶圓2之預定 15 方向之所有的界道23而執行上述半導體層分離步驟的話， 則使工作吸盤31轉動90度，沿著該相對於上述預定方向呈 直角延伸之各界道23來執行上述半導體層分離步驟。 若已實施上述半導體層分離步驟的話，則進行將保護 構件貼附附於光元件晶圓2表面的保護構件貼附步驟。即， 20 200849353 如第6圖⑷及⑻所示，於沿著界道23而形成有雷射加工溝 211之光元件晶圓2表面貼附保護構件4。此保護構件4係使 用氯乙烯等合成樹脂薄片。藉著紫外線或熱性的外在刺激 而於保濩構件4表面積層有黏著力減低的黏著材40，如第6 5囷卬)所示，以黏著材40而貼附於光元件晶圓2表面21a。因 此光元件晶圓2之未形成光元件22的内面2b呈露出的狀 心又，可使用丙烯酸酯系、酯系、聚氨酯系等樹脂所構 成之黏著材作為因外在刺激而使黏著力減低之黏著材40。 若是實施了上述保護構件裝設步驟的話，則實施研削 10已貼著保護構件4之光元件晶圓2之内面2b(藍寶石基板2〇 之内面）而形成預定厚度（光元件22之完成厚度）的内面研削 步驟。此内面研削步驟係藉第7圖所示之研削裝置5而實 施。第7圖所示之研削裝置5包含有保持被加工物之工作吸 盤51、將已保持在該工作吸盤η之被加工物之加工面予以 15研削的研削機構52。工作吸盤51之上面吸取保持被加工物 並使其被朝向第7圖中以箭頭51a所示之方向旋轉。研削機 構52包含有心軸殼體521、可自由旋轉地被支撐在該心軸殼 體521並可被未以圖式顯示之旋轉驅動機構旋轉之旋轉心 轴522、裝設於該旋轉心軸522下端之貼片機523、安裝於該 20貼片機523下面之研削輪524。此研削輪524由圓板狀之基台 525、及環狀地裝設於該基台525下面之砂輪526構成，基台 525安裝於貼片機523下面。 若要使用上述研削裝置5實施内面研削步驟的話，於工 作吸盤51上面載置已實施上述的光半導體層分離步驟並已 11 200849353 貼附保護構件4之光元件晶圓2之保護構件4侧，藉由保護構 件4而將光元件晶圓2吸取保持在工作吸盤51上。因此，已 被吸取保持在工作吸盤51上之光元件晶圓2的内面呈上 側。如此一來，若是已將光元件晶圓2吸取保持在工作吸盤 5 51上的話，使研削機構52之研削輪524朝向箭頭524a所示方 向以例如6000rpm旋轉，並接觸光元件晶圓2之内面2b(藍寶 石基板20内面）而進行研削，藉此將光元件晶圓2形成光元 件22之完成厚度(例如60// m)。藉著如此地實施内面研削步 驟，光元件晶圓2形成厚度例如60/zm薄度，藉著實施上述 10 半導體層分離步驟而沿著界道23分離光半導體層21，因此 外周不會翹起。 若已如上述實施内面研削步驟，並將光元件晶圓2形成 光元件22之完成厚度的話，則轉移至沿著界道23分割光元 件晶圓2的分割步驟，但是，為了使沿著光元件晶圓2之界 I5 道23的分割容易，圖式之實施樣態係實施從光元件晶圓2之 内面側對藍寶石基板20沿著界道23照射具有透過性的雷射 光線，並沿著界道23於藍寶石基板20内部形成變質層的變 質層形成步驟。此變質層形成步驟可使用與上述第3圖所示 之雷射加工裝置3實質上同樣的雷射加工裝置，而變更脈衝 20 雷射光線之波長來實施。因此，以下所述之變質層形成步 驟使用與第3圖所示之雷射加工裝置3之符號相同的符號來 說明。 若要使用上述的雷射加工裝置3實施變質層形成步驛 的話，則如第8圖所示將光元件晶圓2之保護構件4載置於雷 12 200849353 射加工裝置3之工作吸盤31上。以未以圖式顯示之吸取機構 將光元件晶812吸轉持在工作吸触上（晶圓保持步驟）。 因此，被吸取保持在工作吸盤31上的光元件晶圓2的内面2b 成為上側。 5 ^'是已如上述貫施晶圓保持步驟的話，已吸取保持光 元件晶圓2之工作吸㈣藉未以圖式顯示之移動機構而定 位於攝像機構33的正下方。接著，進行藉著攝像麵抓 未以圖式顯示之控制機構進行檢測光元件晶圓2之應進行 雷射加工之加工領域的對準作業。即，攝像機構Μ及未以 10圖式顯示之控制機構執行用以使形成在光元件晶圓2之預 定方向之界道23，與沿著界道23照射雷射光線之雷射光線 照射機構32之聚光器322之對位，即執行圖案匹配等影像處 理，並遂行雷射光線照射位置之對準。又，對於相對於形 成在光元件晶圓2之上述預定方向呈直角延伸之界道辦 15同樣遂行雷射光線照射位置之對準(對準步驟）。此時，雖然 光元件晶圓2之形成有界道22之表面2a的位置處於下側^ 是’由於具有攝像機構23，即具有如上述係以紅外線昭明 機構與可捕捉紅外線之光學系統及可輸出已對應紅外線之 電信號的攝像元件(紅外線CCD)等所構成的攝像機構，因此 20 可從内面2b透出而拍攝界道。 如上所述，若是已實施對準步驟的話，則如第9 所示將工作吸盤朝向用以照射雷射光線之雷射光線照射 機構32之聚光器322所位處之雷射光線照射領域移動，而將 預定的界道23之-端（第9圖⑷之左端）定位於雷射光線照 13 200849353 射機構32之聚光器322的正下方。如此一來，可一面從聚光 器322對藍寶石基板2〇照射具有透過性波長的脈衝雷射光 線，而一面使工作吸盤31以預定的移送速度朝第9圖（a)所系 之箭頭XI所示之方向移動。如第9圖（b)所示，若是聚光器 5 322的位置到達界道23之另一端位置的話，則停止照射脈衡 雷射光線且停止移動工作吸盤31。此變質層形成步驟中， 將脈衝雷射光線之聚光點p配合於藍寶石基板2〇之厚度方 向中央部。其結果如第9圖（b)及第1〇圖所示於藍寶石基板 20 ’沿著界道23而在内部形成變質層201。又，於上述變質 10層形成步驟中，光元件晶圓2形成光元件22之完成厚度（树 如60#m)，惟，光半導體層21係被沿著界道23且依雷射加 工溝211而分離，因此，外周不會翹起，故能容易將雷射光 線之聚光點定位於藍寶石基板2〇内部。爰此，可沿著界道 23而正確地在藍寶石基板20内部形成變質層201。 15 上述變質層形成步驟之加工條件設定為例如以下所 述。 光源 :LED激發Q開關ND ·· YV04 脈衝雷射 波長 :1064nm之脈衝雷射 2〇 反覆頻率 :100kHz 每一脈衝之能量密度 :20J/cm2 聚光點徑度 :ψ 1 βνη 加工移送速度 :300mm/秒 如此一來，若已沿著該延伸存在於光元件晶圓2之預定 14 200849353 方向之所有的界道23而執行上述變質層形成步驟的話，則 使工作吸盤31轉動90度，沿著該相對於上述預定方向呈直 角延伸之各界道23來執行上述變質層形成步驟。 若是如上所述實施了變質層形成步驟的話，則實施將 5光兀件晶圓2之内面貼附於已裝設於環狀框之切割膠帶表 面的晶圓支撐步驟。即，如第丨丨圖化丨及卬)所示，以覆蓋環 狀框6之内側開口部的方式，將光元件晶圓2之内面裝設於 已裝設外周部之切割膠帶7的表面。 若已實施上述晶圓支撐步驟的話，實施對於將已貼附 10於切割膠帶6表面之光元件晶圓2貼附於保護構件4之黏著 材40賦與外在刺激，而使黏著材4〇之黏著力減低的黏著存 減低步驟。即，於第12圖所示之實施樣態中，以紫外線照 射斋8從半導體晶圓2之表面2a所貼附之保護構件4側照射 紫外線。從紫外線照射器8照射之紫外線透過保護構件4並 15照射於黏著材40。其結果，一旦黏著材40你以被賦與如上 述之紫外線等外在刺激時黏著力會減低之黏著劑所形成， 因此可使其降低黏著力。 若已實施上述黏著力減低步驟，則實施從光元件晶圓2 表面剝離保護構件4之保護構件剝離步驟。即 ，以實施上述 2〇黏著力減低步驟而使黏著材40之黏著力減低，因此如第13 圖所不可容易地從光元件晶圓2表面2a剝離保護構件4 若已實施上述保護構件剝離步驟，則實施對已貼附於 裝設在環狀框6之切割膠帶7之光元件晶圓2施予外力，而沿 著已形成雷射加工溝211及變質層2〇1之界道23切斷光元件 15 200849353 晶圓2的晶圓切斷步驟。此晶圓切斷步驟於圖式之實施樣態 中係使用如弟14圖所示之膠帶擴張裝置9來實施。第μ圖所 示之膠帶擴張裝置9包含有可保持上述環狀框6之框保持機 構91、及可擴張已裝設在已保持於該框保持機構91之環狀 5框6之切割膠帶7的膠帶擴張機構92。框保持機構91由環狀 之框保持構件911、及配設於該框保持構件911外周之作為 固疋機構的複數夾箝裔912所構成。框保持構件“I上面形 成有可載置環狀框6之載置面911a，此載置面9iia上可載置 環狀框6。已載置於載置面911a上之環狀框6藉著夾箝器12 1〇而可被固定在框保持構件911。如此構成之框保持機構91藉 著膠帶擴張機構92而被支撐成可進退於上下方向。 膠帶擴張機構92包含有配置在上述環狀之框保持構件 911内侧之擴張筒921。此擴張筒921具有較環狀框6之内徑 小且較貼附於已裝設該環狀框6之切割膠帶7之半導體層圓 15 2之外徑大的内徑及外徑。又，於擴張筒921下端包含有支 撐框緣922。圖式之實施樣態中之膠帶擴張機構92包含有可 使上述裱狀之框保持構件911朝上下方向進退的支撐機構 93。此支撐機構93由配設在上述支撐框緣922上之複數氣缸 931構成，该活塞棒932連結於上述環狀之框保持構件911下 2〇面。如此由複數氣缸931構成之支撐機構93可使上述環狀之 框保持構件911在載置面與擴張筒921之上端約相同高度的 基準位置，與從擴張筒921上端向下預定量下側之擴張位置 之間，移動於上下方向。因此，複數氣缸931所構成之支撐 機構93具有作為使擴張筒921與框保持構件911於上下方向 16 200849353 相對移動之擴張移動機構的機能。 蒼照第15圖來說明使用以上所述構成之膠帶擴張裝置 9來實施的晶圓切斷步驟。即，將裝設了光元件晶圓取著 界運23形成有雷射加卫溝211及變質層2G1)之内面2b所貼 5附之切娜帶7的環狀框6，如第15®⑻所示載置於構成框 保持機構91之框保持構件911之載置面911&上，並藉著夾箝 1§912而固定於框保持構件911。此時，框保持構件911係定 位在第15圖⑷所示的基準位置。接著使構成膠帶擴張機構 92之作為支撐機構93的複數氣缸931作動，並使環狀之框保 1 〇持構件911下降至第15圖（b)所示的擴張位置 。因此，已固定 在框保持構件911之載置_Ua上之環狀框6也下降，故如 第15圖（b)所不使已裝設於環狀框6之切割膠帶7接著擴張筒 921的上端緣擴張。此結果可對已貼著於切割膠帶7之光元 件晶圓2放射狀地作用拉力’因此光元件晶圓2藉著在藍寶 15石基板2 0形成變積層2 01的狀態而沿著已使強度減低之界 道23被切斷並分割成各個光元件22。 又，上述光半導體層分離步驟中，將要形成於光半導 體層21之雷射加ji溝221也深深地形成於藍寶石基板2〇的 $則於貫加上述内面研削步驟後不實施變質層形成步 2〇驟，而係以實施上述晶圓切步驟、黏著力減低步驟、保 護構件剝離步驟、晶圓切_步驟，能沿著界道娜光元件 晶圓2分割成各個光元件22。 又若已貝施上述光半導體層分離步驟及内面研削步 驟’也可不實施變質層形成步驟，而實施上述晶圓支撲步 17 200849353 驟、黏著力減低步驟、保護構件剝離步驟，之後以一般使 用之切削裝置之切削刀具，沿著已形成在光半導體層21之 雷射加工溝221而切斷藍寶石基板20。此時，光元件晶圓2 形成光元件22之完成厚度(例如60//m)，惟，已沿著界道23 5 並藉著雷射加工溝211而分離了光半導體層21，因此外周不 會翹起，故能以切削刀具正確地切斷光元件晶圓2。 【圖式簡單說明3 第1圖表示依據本發明所構成之晶圓加工方法而分割 之作為晶圓的光元件晶圓的立體圖。 10 弟2圖择員不弟1圖所不之光元件晶圓之剖面放大圖。 第3圖係依據本發明構成之晶圓加工方法中，用以實施 光半導體層分離步驟之雷射加工裝置的重要部分立體圖。 第4圖（a)、（b)係表示依據本發明構成之晶圓加工方法 之光半導體層分離步驟的說明圖。 15 第5圖表示已實施光半導體層分離步驟之光元件晶圓 的剖面放大圖。 第6圖（a)、（b)係表示依據本發明構成之晶圓加工方法 之保護構件裝設步驟的說明圖。 弟7圖表不依據本發明構成之晶圓加工方法之内面研 20 削步驟的說明圖。 第8圖係依據本發明構成之晶圓加工方法中，用以實施 變質形成步驟之雷射加工裝置的重要部分立體圖。 第9圖（a)、（b)表示依據本發明構成之晶圓加工方法之 變質形成步驟的說明圖。 18 200849353 第ίο圖表示已實施變質層形成步驟之光元件晶圓的剖 面放大圖。 第11圖（a)、（b)表示依據本發明構成之晶圓加工方法之 晶圓支撐步驟的說明圖。 5 第12圖表示依據本發明構成之晶圓加工方法之黏著力 減低步驟的說明圖。 第13圖表示依據本發明構成之晶圓加工方法之保護構 件剝離步驟的說明圖。 第14圖係依據本發明構成之晶圓加工方法中，用以實 10 施晶圓切斷步驟之膠帶擴張装置的立體圖。 第15圖（a)、（b)表示依據本發明構成之晶圓加工方法之 晶圓切斷步驟的說明圖。 【主要元件符號說明】 2…光元件晶圓 31…雷射加工裝置之工作吸盤 2a…表面 32···雷射光線照射機構 2b···内面 321…圓筒狀殼體 20…藍寶石基板 322…聚光器 20l···變質層 33…攝賴構 21…光半導體層 4…保護構件 211···雷射加工溝 40…黏著材 22…光元件 5…研削裝置 23…界道 51··研削裝置之工作吸盤 3···雷射加工裝置 51a···箭頭 19 200849353 52…研削機構 521…心軸殼體 522…旋轉心軸 523…貼片機 524···研削輪 524a…箭頭 525…基台 526…砂輪 6…環狀框 7…切割膠帶 8···紫外線照射器 9…膠帶擴張裝置 91…框保持機構 91 l···框保持構件 911a···載置面 912···夾箝器 92…膠帶擴張機構 921…擴張筒 922…支撐框緣 93…支撐機構 931…氣缸 932···活塞棒 XI、X2…箭頭 P…聚光點 20[The best mode for implementing the invention] 1 〇 ^ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Fig. 1 shows that the wafer processing method constructed by the present invention can be divided into. The light θ circle of the 7L piece is the perspective view of the optical element wafer, and the second figure shows the enlarged part of the important part of the 7L piece of the light of the drawing. The first! In the light-emitting semiconductor layer 2 composed of a nitride semiconductor layer of a sapphire substrate, a plurality of optical elements 22 are formed in a matrix, and the optical elements 22 are formed in a matrix. The scorpion-like (grid-like) boundary 23 is further divided, and the stone substrate 20 is formed to have a thickness of, for example, 700/m. Further, the photo-semiconductor layer 21 composed of the nitride semi-V body layer is formed on the surface of the gemstone substrate 20 by, for example, a stupid crystal method. In order to divide the optical element wafer 2 along the boundary 23, first, laser light having a wavelength which is absorptive to the optical semiconductor layer 21 is formed along the boundary 23 formed on the surface of the optical element wafer 2, And separating the photo-semiconductor layer separating step of the photo-semiconductor layer 21. This photo-semiconductor layer separation step is carried out in accordance with the laser processing apparatus shown in Fig. 3 at 7 200849353. The laser processing apparatus 3 shown in FIG. 3 includes a working light suction cup 3 for holding a workpiece, and a laser beam irradiation mechanism 32 for irradiating the workpiece to be held on the working suction cup 31 with laser light. It is possible to photograph the image pickup mechanism 33 of the workpiece that has been held on the work suction cup 31. The working suction cup 31 is constructed to be capable of sucking and holding the workpiece, and the working suction cup 31 is oriented toward the processing transfer direction indicated by the arrow X in FIG. 3 and indicated by the arrow γ by a moving mechanism not shown in the drawing. The indexing direction moves. The laser beam illumination mechanism 32 includes a cylindrical housing 32 that is substantially horizontally disposed. The housing 321 is provided with a YAG laser oscillator or a YV04 laser oscillator that is not shown in the drawings. A pulsed laser ray oscillator or a pulsed laser ray oscillating mechanism having a repeating frequency setting mechanism. The front end of the casing 321 is provided with a concentrator 322 for collecting the pulsed laser light oscillated by the pulsed laser ray oscillating mechanism. The image pickup mechanism 33 attached to the front end portion of the casing 321 constituting the above-described laser beam irradiation mechanism 32 is more in addition to the normal image pickup device (CCD) which is imaged by visible light in the embodiment of the drawing. An infrared illuminating mechanism that irradiates infrared rays to the workpiece, an optical system that can capture infrared rays irradiated by the infrared illuminating mechanism, and an imaging element (infrared CCD) that can output an electric signal corresponding to 20 infrared rays captured by the optical system. And send the captured image signal to a control mechanism that is not shown in the figure. In the step of performing the photo-semiconductor layer separation using the laser processing apparatus 3 described above, the inner surface of the optical element wafer 2 is placed on the working chuck 31 of the laser processing apparatus 3 as shown in Fig. 3. The light 200849353 component wafer 2 is held by the suction device 31 by the suction mechanism not shown in the figure (wafer holding step). Therefore, the surface 2a of the optical element wafer 2 held on the working suction port M v > T t and the side 31 is on the upper side. As described above, the working chuck that has sucked and held the optical element wafer 2 is moved toward the imaging mechanism 33 by the processing transfer mechanism not shown in the drawing: When the work chuck 31 is positioned directly below the image pickup mechanism 33, the alignment operation in the field of processing for detecting the laser wafer 2 to be subjected to laser processing is performed by the image pickup mechanism 33 and the control mechanism not shown in the drawing. That is, the imaging mechanism 33 and the control mechanism not shown in the figure perform the irradiation of the laser light for irradiating the laser beam along the boundary 23 with the boundary 23 formed in the predetermined direction of the light H) element wafer 2 The alignment (closed position) of the concentrator 322 of the mechanism 32 performs image processing such as pattern matching and aligns the position of the laser beam irradiation. Further, the alignment of the laser beam irradiation position is also performed with respect to the boundary 23 extending at a right angle to the predetermined direction of the optical element wafer 2. 15 As described above, when the boundary 23 of the optical element wafer 2 that has been held on the working chuck 31 is detected and the alignment of the laser beam irradiation position is performed, the operation will be performed as shown in Fig. 4(a). The chuck 31 is moved toward the field of laser light irradiation at the position of the concentrator 322 of the laser beam illumination mechanism 32 for illuminating the laser beam, and the predetermined boundary 23 is positioned directly below the concentrator 322. At 20 o'clock, as shown in Fig. 4 (4), one end of the boundary 23 of the optical element wafer 2 (as the left end of Fig. 4(a)) is positioned directly below the concentrator 322. Next, the pulsed laser beam having an absorptive wavelength to the photo-semiconductor layer 21 is irradiated from the concentrator 322 of the laser beam irradiation unit 32, and the working chuck 31 is oriented toward the fourth figure (a) at a predetermined processing transfer speed. The direction indicated by the arrow X1 is 9 200849353 (optical semiconductor layer separation step). As shown in Fig. 4(b), when the other end of the boundary 23 (the right end of Fig. 4) reaches the position directly below the concentrator 322, the irradiation of the ray is stopped and the movement of the working chuck 31 is stopped. As a result, as shown in FIG. 4(b) and FIG. 5, the laser processing trench 2U is formed on the light semiconducting body layer 21 formed on the surface of the optical element wafer 2, and the optical semiconductor layer 2 is along the boundary. Separation. In the semiconductor layer separating step, the light collecting point of the pulsed laser light is fitted in the vicinity of the upper surface of the photo-semiconductor layer 21. When the semiconductor layer separation step is performed, the thickness of the optical element wafer 2 is, for example, 700, so that the outer peripheral portion is not warped, so that the concentrated light spot P of the pulsed laser light can be surely positioned on the upper surface of the light semiconductor layer 21 nearby. Further, the above semiconductor layer separation step is carried out, for example, under the following processing conditions. Light source of laser light: YAG Laser wavelength: 355nm Overlap frequency: 100kHz Energy density per pulse: 15J/cm2 Concentration point diameter: 10 // m Processing transfer speed: 200mm/sec So, if When the semiconductor layer separation step is performed by extending all of the boundary paths 23 existing in the predetermined 15 directions of the optical element wafer 2, the working chuck 31 is rotated by 90 degrees, and extends at a right angle with respect to the predetermined direction. The above-described semiconductor layer separation step is performed by the various channels 23. When the semiconductor layer separation step has been carried out, a protective member attaching step of attaching the protective member to the surface of the optical element wafer 2 is performed. That is, 20 200849353 as shown in Fig. 6 (4) and (8), the protective member 4 is attached to the surface of the optical element wafer 2 on which the laser processing groove 211 is formed along the boundary 23 . This protective member 4 is made of a synthetic resin sheet such as vinyl chloride. The adhesive material 40 having a reduced adhesion to the surface layer of the protective member 4 by ultraviolet or thermal external stimulation is attached to the surface 21a of the optical element wafer 2 with the adhesive 40 as shown in FIG. . Therefore, the inner surface 2b of the optical element wafer 2 in which the optical element 22 is not formed is exposed, and an adhesive made of a resin such as an acrylate type, an ester type or a polyurethane type can be used as the external stimulus to reduce the adhesion. Adhesive material 40. When the protective member mounting step is performed, the grinding 10 is applied to the inner surface 2b of the optical element wafer 2 of the protective member 4 (the inner surface of the sapphire substrate 2) to form a predetermined thickness (the completed thickness of the optical element 22). Inner grinding step. This inner surface grinding step is carried out by the grinding device 5 shown in Fig. 7. The grinding device 5 shown in Fig. 7 includes a working chuck 51 for holding a workpiece, and a grinding mechanism 52 for grinding the machined surface of the workpiece held by the working chuck n. The upper surface of the working chuck 51 sucks and holds the workpiece and is rotated in the direction indicated by the arrow 51a in Fig. 7. The grinding mechanism 52 includes a spindle housing 521, a rotating spindle 522 rotatably supported by the spindle housing 521 and rotatable by a rotary drive mechanism not shown, and mounted on the rotary spindle 522 The lower end placement machine 523 is mounted on the grinding wheel 524 under the 20 placement machine 523. The grinding wheel 524 is composed of a disk-shaped base 525 and a grinding wheel 526 which is annularly mounted under the base 525, and the base 525 is attached to the lower surface of the placement machine 523. When the inner surface grinding step is carried out by using the above-described grinding device 5, the protective member 4 side of the optical element wafer 2 to which the protective member 4 has been attached is placed on the upper surface of the working chuck 51. The optical element wafer 2 is sucked and held on the working chuck 51 by the protective member 4. Therefore, the inner surface of the optical element wafer 2 which has been sucked and held on the working chuck 51 is on the upper side. In this way, if the optical element wafer 2 has been sucked and held on the working chuck 51, the grinding wheel 524 of the grinding mechanism 52 is rotated at, for example, 6000 rpm in the direction indicated by the arrow 524a, and contacts the inner surface of the optical element wafer 2. 2b (the inner surface of the sapphire substrate 20) is ground, whereby the optical element wafer 2 is formed to have a completed thickness (for example, 60//m) of the optical element 22. By performing the inner surface grinding step in this manner, the optical element wafer 2 is formed to have a thickness of, for example, a thickness of 60/zm, and the optical semiconductor layer 21 is separated along the boundary 23 by performing the above-described 10 semiconductor layer separation step, so that the outer circumference does not rise. . If the inner surface grinding step is performed as described above and the optical element wafer 2 is formed to have the completed thickness of the optical element 22, the process proceeds to the division step of dividing the optical element wafer 2 along the boundary 23, but in order to The division of the I5 track 23 at the boundary of the component wafer 2 is easy, and the implementation of the pattern is performed by irradiating the sapphire substrate 20 with the transparent laser light from the inner surface side of the optical element wafer 2 along the boundary 23, and along the edge. The altered layer forming step of forming the altered layer inside the sapphire substrate 20 is formed. This altered layer forming step can be carried out by using the laser processing apparatus substantially the same as the laser processing apparatus 3 shown in Fig. 3 described above, and changing the wavelength of the pulse 20 laser light. Therefore, the altered layer forming step described below will be described using the same reference numerals as those of the laser processing apparatus 3 shown in Fig. 3. To perform the metamorphic layer forming step using the above-described laser processing apparatus 3, the protective member 4 of the optical element wafer 2 is placed on the working chuck 31 of the Ray 12 200849353 shot processing apparatus 3 as shown in FIG. . The optical element crystal 812 is held in the working contact by a suction mechanism not shown in the drawing (wafer holding step). Therefore, the inner surface 2b of the optical element wafer 2 sucked and held on the working chuck 31 is on the upper side. 5 ^' is that the wafer holding step of the holding optical element wafer 2 has been sucked as described above, and is positioned directly below the image pickup mechanism 33 by a moving mechanism not shown in the drawing. Next, an alignment operation in the processing field in which the laser device wafer 2 is to be subjected to laser processing is performed by the control unit that is not shown in the drawing by the image pickup surface. That is, the imaging mechanism Μ and the control mechanism not shown in FIG. 10 perform a laser beam irradiation mechanism for irradiating the boundary light 23 formed in the predetermined direction of the optical element wafer 2 with the laser beam along the boundary line 23 The alignment of the concentrator 32 of 32, that is, image processing such as pattern matching is performed, and the alignment of the laser light irradiation position is performed. Further, the alignment of the laser light irradiation position is also performed with respect to the boundary path 15 which is formed at a right angle in the predetermined direction of the optical element wafer 2 (alignment step). At this time, although the position of the surface 2a of the optical element wafer 2 on which the boundary track 22 is formed is on the lower side, it is "having an imaging mechanism 23, that is, an optical system capable of capturing infrared rays as described above and an optical system capable of capturing infrared rays" Since an imaging unit including an imaging element (infrared CCD) that corresponds to an electric signal of infrared rays is output, 20 can be seen from the inner surface 2b to capture an interface. As described above, if the alignment step has been performed, the working chuck is moved toward the field of the laser beam irradiation at the position of the concentrator 322 of the laser beam irradiation mechanism 32 for irradiating the laser light as shown in the ninth. And the end of the predetermined boundary 23 (the left end of Fig. 9 (4)) is positioned directly below the concentrator 322 of the laser light 13 of the 2008-04353 radiation mechanism 32. In this way, the sapphire substrate 2 can be irradiated with pulverized laser light having a transparent wavelength from the concentrator 322, and the working chuck 31 can be directed to the arrow XI of FIG. 9(a) at a predetermined transfer speed. Move in the direction shown. As shown in Fig. 9(b), if the position of the concentrator 5 322 reaches the other end position of the boundary track 23, the irradiation of the pulsating laser light is stopped and the movement of the working suction cup 31 is stopped. In the altered layer forming step, the focused spot p of the pulsed laser light is fitted to the central portion of the thickness direction of the sapphire substrate 2''. As a result, the altered layer 201 is formed inside the sapphire substrate 20' along the boundary 23 as shown in Fig. 9(b) and Fig. 1 . Further, in the above-described metamorphic 10-layer forming step, the optical element wafer 2 forms a finished thickness (tree such as 60#m) of the optical element 22, but the optical semiconductor layer 21 is along the boundary 23 and is processed by the laser processing groove. Since the 211 is separated, the outer circumference is not lifted, so that the light collecting point of the laser light can be easily positioned inside the sapphire substrate 2 . Thus, the altered layer 201 can be formed correctly inside the sapphire substrate 20 along the boundary 23. The processing conditions of the above-described altered layer forming step are set, for example, as described below. Light source: LED excitation Q switch ND ·· YV04 Pulse laser wavelength: 1064nm pulse laser 2〇 Repeat frequency: 100kHz Energy density per pulse: 20J/cm2 Concentration point diameter: ψ 1 βνη Processing transfer speed: 300mm In this case, if the metamorphic layer forming step is performed along all the boundaries 23 extending in the predetermined 14 200849353 direction of the optical element wafer 2, the working chuck 31 is rotated by 90 degrees. The tempering layer forming step is performed by the trajectory 23 extending at right angles to the predetermined direction. When the modified layer forming step is carried out as described above, the wafer supporting step of attaching the inner surface of the 5-optical wafer 2 to the surface of the dicing tape attached to the annular frame is carried out. That is, as shown in FIG. 2, the inner surface of the optical element wafer 2 is mounted on the surface of the dicing tape 7 on which the outer peripheral portion is mounted so as to cover the inner opening of the annular frame 6. . If the above-described wafer supporting step has been carried out, the bonding material 40 to which the optical element wafer 2 attached to the surface of the dicing tape 6 is attached to the protective member 4 is externally irritated, and the adhesive material is applied. The adhesion reduction is reduced by the adhesion reduction step. That is, in the embodiment shown in Fig. 12, the ultraviolet ray 8 is irradiated with ultraviolet rays from the side of the protective member 4 to which the surface 2a of the semiconductor wafer 2 is attached. The ultraviolet ray irradiated from the ultraviolet ray irradiator 8 is transmitted through the protective member 4 and 15 to the adhesive 40. As a result, once the adhesive 40 is formed by an adhesive which is reduced in adhesion when external stimulation such as ultraviolet rays as described above is applied, the adhesive force can be lowered. When the adhesion reducing step is performed, the protective member peeling step of peeling off the protective member 4 from the surface of the optical element wafer 2 is performed. In other words, since the adhesive force of the adhesive member 40 is reduced by performing the above-described 2〇 adhesive force reduction step, the protective member 4 can not be easily peeled off from the surface 2a of the optical element wafer 2 as shown in Fig. 13 Then, an external force is applied to the optical element wafer 2 attached to the dicing tape 7 mounted on the ring frame 6, and is cut along the boundary 23 where the laser processing groove 211 and the metamorphic layer 2〇1 have been formed. Light-breaking element 15 200849353 Wafer cutting step of wafer 2. This wafer cutting step is carried out using the tape expanding device 9 as shown in Fig. 14 in the embodiment of the drawings. The tape expanding device 9 shown in Fig. 5 includes a frame holding mechanism 91 that can hold the annular frame 6, and a dicing tape 7 that can be expanded and mounted on the ring-shaped frame 5 of the frame holding mechanism 91. Tape expansion mechanism 92. The frame holding mechanism 91 is composed of an annular frame holding member 911 and a plurality of clamp members 912 which are disposed on the outer periphery of the frame holding member 911 as a fixing mechanism. The frame holding member "I is formed with a mounting surface 911a on which the annular frame 6 can be placed, and the annular frame 6 can be placed on the mounting surface 9iia. The annular frame 6 that has been placed on the mounting surface 911a is borrowed. The clamp 12 is fixed to the frame holding member 911. The frame holding mechanism 91 thus constructed is supported by the tape expansion mechanism 92 so as to be movable in the up and down direction. The tape expansion mechanism 92 includes a ring disposed therein. The expansion frame 921 inside the frame holding member 911 has a smaller inner diameter than the annular frame 6 and is attached to the semiconductor layer circle 15 of the dicing tape 7 on which the annular frame 6 is mounted. The outer diameter and the outer diameter of the outer diameter of the expansion cylinder 921 include a support frame edge 922. The tape expansion mechanism 92 in the embodiment of the embodiment includes the frame-shaped holding member 911 which can make the above-mentioned dome-shaped member a support mechanism 93 that advances and retreats. The support mechanism 93 is composed of a plurality of cylinders 931 disposed on the support frame edge 922, and the piston rod 932 is coupled to the lower surface of the annular frame holding member 911. The supporting mechanism 93 constituted by 931 can make the above-mentioned annular frame holding member The reference position of the 911 at the same height as the upper end of the expansion tube 921 is moved in the up-and-down direction between the expansion position from the upper end of the expansion tube 921 to the lower side of the predetermined amount. Therefore, the support constituted by the plurality of cylinders 931 The mechanism 93 has a function as an expansion/movement mechanism that relatively moves the expansion tube 921 and the frame holding member 911 in the vertical direction 16 200849353. The wafer cutting performed by the tape expansion device 9 configured as described above will be described with reference to Fig. 15 The ring-shaped frame 6 is attached to the optical element wafer, and the ring-shaped frame 6 attached to the inner surface 2b of the laser-assisted trench 211 and the altered layer 2G1) is attached. The 15th (8) is placed on the mounting surface 911 & amp of the frame holding member 911 constituting the frame holding mechanism 91, and is fixed to the frame holding member 911 by the clamp 1 § 912. At this time, the frame holding member 911 It is positioned at the reference position shown in Fig. 15 (4). Then, the plurality of cylinders 931 as the supporting mechanism 93 constituting the tape expanding mechanism 92 are actuated, and the ring-shaped frame holding member 911 is lowered to the 15th figure (b). ) the expanded position shown. Therefore, The annular frame 6 placed on the mounting_Ua of the frame holding member 911 is also lowered. Therefore, as shown in Fig. 15(b), the cutting tape 7 which has been mounted on the ring frame 6 is not caused to extend the upper end of the cylinder 921. The result is that the tensile force acts on the optical element wafer 2 that has been attached to the dicing tape 7 radially. Therefore, the optical element wafer 2 is formed along the sapphire 15 stone substrate 20 to form the delamination layer 201. The boundary 23 in which the intensity is reduced is cut and divided into the respective optical elements 22. Further, in the optical semiconductor layer separating step, the laser ji groove 221 to be formed on the optical semiconductor layer 21 is also deeply formed. The sapphire substrate 2 is not subjected to the above-described inner surface grinding step, and the wafer cutting step, the adhesion reducing step, the protective member peeling step, and the wafer cutting step are performed. It can be divided into individual optical elements 22 along the boundary light element wafer 2 . Further, if the above-described photo-semiconductor layer separation step and the in-plane grinding step are not performed, the wafer baffle step 17 200849353, the adhesion reduction step, and the protective member peeling step may be performed, and then used in general. The cutting tool of the cutting device cuts the sapphire substrate 20 along the laser processing groove 221 formed in the optical semiconductor layer 21. At this time, the optical element wafer 2 forms the completed thickness (for example, 60//m) of the optical element 22, but the optical semiconductor layer 21 has been separated by the laser processing groove 211 along the boundary 23, and thus the outer periphery Since it is not lifted, the optical element wafer 2 can be cut accurately by the cutting tool. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing an optical element wafer as a wafer divided by a wafer processing method constructed by the present invention. 10 Brother 2 Figure 2 is an enlarged view of the section of the light component wafer. Fig. 3 is a perspective view of an essential part of a laser processing apparatus for performing a photo-semiconductor layer separation step in a wafer processing method constructed in accordance with the present invention. Fig. 4 (a) and (b) are explanatory views showing a step of separating an optical semiconductor layer in a wafer processing method constructed in accordance with the present invention. 15 Fig. 5 is an enlarged cross-sectional view showing the optical element wafer on which the photo-semiconductor layer separation step has been performed. Fig. 6 (a) and (b) are explanatory views showing the steps of installing the protective member of the wafer processing method constructed in accordance with the present invention. Figure 7 is an illustration of the internal grinding process of the wafer processing method according to the present invention. Fig. 8 is a perspective view of an essential part of a laser processing apparatus for performing a metamorphic forming step in a wafer processing method constructed in accordance with the present invention. Fig. 9 (a) and (b) are explanatory views showing a modification forming step of the wafer processing method constructed in accordance with the present invention. 18 200849353 FIG. 9 is a cross-sectional enlarged view showing a wafer of an optical element in which an altered layer forming step has been performed. Fig. 11 (a) and (b) are explanatory views showing a wafer supporting step of a wafer processing method constructed in accordance with the present invention. Fig. 12 is an explanatory view showing a step of reducing the adhesion force of the wafer processing method constructed in accordance with the present invention. Fig. 13 is an explanatory view showing a step of peeling off the protective member of the wafer processing method constructed in accordance with the present invention. Fig. 14 is a perspective view of a tape expanding device for performing a wafer cutting step in a wafer processing method constructed in accordance with the present invention. Fig. 15 (a) and (b) are explanatory views showing a wafer cutting step of the wafer processing method constructed in accordance with the present invention. [Explanation of main component symbols] 2...Optical component wafer 31...Working chuck 2a of laser processing apparatus...Surface 32···Laser light irradiation mechanism 2b··· Inner surface 321... Cylindrical housing 20...Sapphire substrate 322 ... concentrator 20l···metamorphism layer 33...photodetection structure 21...photo-semiconductor layer 4...protective member 211··· laser processing trench 40...adhesive material 22...optical element 5...grinding device 23...boundary 51· - Working chuck for grinding device 3 · Laser processing device 51a··· arrow 19 200849353 52... grinding mechanism 521... spindle housing 522... rotating spindle 523... mounting machine 524··· grinding wheel 524a... arrow 525...Abutment 526...Wheel wheel 6...Ring frame 7...Cutting tape 8··· UV illuminator 9... Tape expansion device 91: Frame holding mechanism 91 l···Frame holding member 911a··· Mounting surface 912· Clamps 92... Tape expansion mechanism 921... Expansion cylinder 922... Support frame 93... Support mechanism 931... Cylinder 932···Piston rod XI, X2... Arrow P... Concentration point 20