200914185 玖、發明說明 【發明所屬之技術領域】 本發明係關於加工方法，特別是使用雷射之 【先前技術】 近年來對具有在Al2〇3基板上藉晶體成長法 等之半導體動作層以作爲半導體元件，和在玻璃 貼其它之玻璃基板等以作爲液晶顯示裝置等，各 造之加工對象物’以高精確度切斷之技術之需求 〇 以往’欲切斷具有這些疊層構造之加工對象 係使用刀切法（b 1 a d e - d i c i n g)和鑽石描刻法 scribe)。 刀切法係藉鑽石刀片等切削加工對象物以行 法。而鑽石描刻法則是藉鑽石尖刀具（diamond ρι 在加工對象物之表面上畫出描刻線，然後將7 e d g e)沿著此描刻線（s c r i b e 1 i n e)擠壓加工對象物 藉此割斷加工對象物之方法。 不過’刀切法之情形，例如，加工對象物， 晶顯示裝置用之情形時則因在玻璃基板與其它玻 設有間隙之故，會有切削層和潤滑洗淨水進入間 另外’鑽石描刻法法之情形，加工對象物 Al2〇3基板等之硬度高之基板之情形時，或力口工 加工方法 生長GaN 基板上黏 種疊層構 日益殷切 物，一般 (diamond 切斷之方 )int tool) □ (knife 之裏面， 係上述液 璃基板間 隙之虞。 若是具有 對象物若 200914185 係玻璃基板相互黏合而成之情形時，則不僅須在加工對象 物之表面’裏面也要畫出描刻線，從而在表面和裏面上畫 出之描刻線因位置之偏離而有產生切斷不良之虞。 【發明內容】 因此’本發明鑑於上述之情事而創作出者，其目的係 提供一種能解決上述之問題，即便加工對象物係爲具有種 種疊層構造’也能以高精確度切斷加工對象物之雷射加工 方法。 爲達成上述目的，本發明有關之雷射加工方法，其特 徵爲一種切斷包含基板和設在基板上之疊層部之平板狀之 加工對象物之雷射加工方法，包括下述作業：在加工對象 物之疊層部側之表面安裝保護膜；將加工對象物之裏面作 爲雷射光入射面，在基板內部對齊集光點照射雷射光，藉 此形成多光子吸收所產生之改質區域；藉此改質區域，沿 著加工對象物之切斷預定線在距雷射光入射面既定距離內 側形成切斷起點區域；在加工對象物之裏面安裝延展性薄 膜；及將以切斷起點區域爲起點切斷加工對象物所產生之 多數部份，藉延展性薄膜之伸展而相互分離。 另外，本發明有關之雷射加工方法，其係一種切斷包 含半導體基板和設在半導體基板上之疊層部之平板狀之加 工對象物之雷射加工方法，其特徵爲包括下述作業：在加 工對象物之疊層部側之表面安裝保護膜；將加工對象物之 裏面作爲雷射光入射面，在半導體基板內部對齊集光點照 -6 - 200914185 射雷射光藉以形成熔融處理區域；藉此熔融處理區域，沿 著加工對象物之切斷線在距雷射光入射面既定距離之內側 形成切斷起點區域；對加工對象物之裏面安裝延展性薄膜 ;及將以切斷起點區域爲起點，切斷加工對象物所產生之 多數部份藉延展性薄膜之伸展使其等相互分離。 依這些雷射加工方法，藉在加工對象物之表面安裝保 護膜，藉此能將加工對象物之裏面朝上而載置於台上，因 此’能從加工對象物之裏面將雷射光較佳地照射到（半導 體）基板之內部。又，藉多光子吸收現象所形成之改質區 域（熔融處理區域），在基板內部形成爲了切斷加工對象物 而沿著所要之切斷預定線之切斷起點區域，進而能以此切 斷起點區域爲起點切斷加工對象物。又，於加工對象物之 裏面安裝延展性薄膜，藉伸展此薄膜，能容易地使被切斷 之加工對象物之多數部份分離。換言之，依雷射加工方法 ’除了不直接對位在加工對象物之表面之疊層部照射雷射 光而能形成切斷起點區域，另能以切斷起點區域爲起點， 以較小之力及較佳精確度割斷基板，且能易於將切斷之加 工對象物分離。因此，依此雷射加工方法，即便加工對象 物係爲具有種種疊層構造之情形時也能以高精確度切斷該 加工對象物。 這裏’基板上之疊層部係指堆疊在基板之表面之物， 黏貼在基板之表面之物，或者裝設在基板之表面之物，是 否與基板不同材料或同種材料皆無所謂。又，在疊層部上 ’也有與基板密接而設者，也有與基板隔一間隙而設者。 200914185 其例有在基板上藉晶體成長而形成之半導體動作層和’黏 貼在玻璃基板上之其它玻璃基板等，疊層部也包含由多數 層不同材料所形成者。基板之內部係也包含設置疊層部之 基板之表面上之義。另外，所謂集光點係爲雷射光集光之 地點。又，切斷起點區域也有藉改質區域連續地形成而形 成之情形，也有藉改質區域斷續地形成而形成之情形。 另外，本發明有關之雷射加工方法，其係一種切斷包 含基板，設在基板上之疊層部之平板狀之加工對象物之雷 射加工方法，其特徵包括下述作業：在加工對象物之疊層 部側之表面安裝保護膜；將加工對象物之裏面作爲雷射光 入射面，在基板內部對齊集光點照射雷射光藉此形成因多 光子吸收所產生之改質區域；藉此改質區域，沿著加工對 象物之切斷預定線，在距雷射光入射面既定距離內側形成 切斷起點區域；在加工對象物之裏面安裝延展性薄膜；藉 加工對象物施加外力並切斷起點區域爲起點將加工對象物 切斷成多數部份，及使延展性薄膜伸展而將加工對象物之 多數部份予以分離。 另外，本發明有關之雷射加工方法，其係一種切斷包 含基板和設於基板上之疊層部之平板狀之加工對象物之雷 射加工方法，其特徵包括下述作業：在加工對象物之疊層 部側之表面安裝保護膜；將加工對象物之裏面作爲雷射光 入射面，在基板之內部對齊集光點照射雷射光以形成藉多 光子吸收所產生之改質區域；藉此改質區域，沿著加工對 象物之切斷在距雷射光入射面既定距離內側形成切斷起點 -8- 200914185 區域；在加工對象物之裏面安裝延展性薄膜；藉對加工對 象物施加外力’使以切斷起點區域爲起點，將加工對象物 切斷成多數部份；及使延展性薄膜伸展，進而分離加工對 象物之多數部份。 依這些雷射加工方法’藉與上述之雷射加工方法相同 之理由’即便加工對象物是爲具有各種疊層構造之情形也 能以高精確度切斷該加工對象物。另外，在將加工對象物 切斷成多數部份之際，藉對加工對象物施加外力，能容易 地以切斷起點區域爲起點切斷加工對象物。 另外，本發明有關之雷射加工方法，其係一種切斷包 含基板和設於基板上之疊層部之平板狀之加工對象物之雷 射加工方法，其特徵包括下述作業：在加工對象物之疊層 部側之表面安裝保護膜；將加工對象物之裏面作爲雷射光 入射面，在基板之內部對齊集光點照射雷射光以形成藉多 光子吸收所產生之改質區域；藉此改質區域，沿著加工對 象物之切斷預定線在距雷射光入射面既定之距離內側形成 切斷起點區域；在加工對象物之裏面安裝延展性薄膜；及 使延展性薄膜伸展’藉此以切斷起點區域爲起點將加工對 象物切斷成多數部份，另同時將加工對象物之多數部份予 以分離。 另外，本發明有關之雷射加工方法，其係一種切斷包 含半導體基板和設在半導體基板上之疊層部之平板狀之加 工對象物之雷射加工方法，其特徵包括下述作業：在加工 對象物之疊層部側之表面安裝保護膜；將加工對象物之裏 -9- 200914185 面作爲雷射光入射面’在半導體基板內部對齊集光點照射 雷射光藉以形成熔融處理區域；藉此熔融處理區域，沿著 加工對象物之切斷預定線在距雷射光入射面既定距離之內 側形成切斷起點區域；在加工對象物之裏面安裝延展性薄 膜；及使延展性薄膜伸展，藉此以切斷起點區域爲起點將 加工對象物切斷成多數部份，另同時將加工對象物之多數 之部份分離。 依這些雷射加工方法，藉與上述之雷射加工方法相同 之理由’即便加工對象物係爲具有各種疊層構造之情形時 也能以高精確度切斷該加工對象物。另外，使延展性薄膜 伸展’藉以對加工對象物之切斷起點區域施加拉伸，因此 ’能同時執行切斷加工對象物之作業和分離多數之部份之 作業，進而能減少製造作業。 另外，上述之本發明有關之雷射加工方法，較佳地在 於加工對象物上形成切斷起點區域之前硏磨加工對象物之 裏面俾薄化加工對象物。藉此’能以較小之力或不須要特 別之力’以切斷起點區域爲起點精確地切斷加工對象物。 另外’上述本發明有關之雷射加工方法，係較佳地在 加工對象物安裝延展性薄膜後即除去保護膜。藉此，能把 持形成切斷起點區域之加工對象物使不致離散。或較佳地 使延展性薄膜伸展藉以分離加工對象物之多數之部份後才 去除保護膜。藉此，從切斷加工對象物後直到取出多數之 部份止之期間能保護該多數之部份。 -10- 200914185 【實施方式】 (實施發明之最佳形態） 下文將參照圖面詳細地說明本發明之較佳實施例。本 實施形態有關之雷射加工方法係在加工對象物之內部形成 藉多光子吸收所產生之改質區域。因此’本雷射加工方法 首先係特別地說明多光子吸收。 光子能量hv若小於材料之吸收帶隙Eg時在光學上即 呈透明。是於，在材料上產生吸收之條件係hv>EG。但是 ，即便光學上是透明，雷射光之強度若非常大時則藉 nhv>EG之條件〇 = 2,3,4,···)在材料上產生吸收。此現象係 稱爲多光子吸收。若爲脈衝波之情形時雷射光之強度係由 雷射光之集光點尖峰功率（power peak)密度（W/cm2)所決定 ，例如以尖峰功率密度爲lxl〇8(W/cm2)以上之條件，則會 產生多光子吸收。尖峰功率密度係由（集光點上之雷射光 每個脈衝之能量）+ (雷射光之束點斷面積X脈衝寬）求得。 另外，若係爲連續波之情形時雷射光之強度係由雷射光之 集光點之電場強度（W/cm2)決定。 接著，將參照第1〜第6圖說明有關利用這種多光子 吸收之本實施形態之雷射加工原理。第1圖係雷射加工中 之加工對象物1之平面圖，第2圖係沿著第1圖所示之加 工對象物1之11-II線之斷面圖，第3圖係雷射加工後之 加工對象物1之平面圖，第4圖係沿著第3圖所示之加工 對象物1之IV-IV線之斷面圖，第5圖係沿著第3圖所示 之加工對象物1之V-V線之斷面圖，第6圖係切斷後之 -11 - 200914185 加工對象物1之平面圖。 如第1圖及2圖所示’加工對象物1之面1〇上有切 斷加工對象物1所需之切斷預定線5。切斷預定線5係呈 直線狀延伸之假想線（也可對加工對象物1實際地畫線以 作爲切斷預定線5)。本實施形態有關之雷射加工係以產 生多光子吸收之條件在加工對象物丨之內剖對齊集光點p 對加工對象物1照射雷射光L以形成改質區域7。另外， 所5胃集光點係爲雷射光L集光之地點。另外，加工對象物 1之面10係成爲雷射光入射之雷射光入射面，該面1〇爲 了防止雷射光L之散亂係良好地爲平坦且光滑之面。 沿著切斷預定線5(亦即沿著箭頭A方向）相對地移動 雷射光L，從而沿著切斷預定線5移動集光點p。藉此， 如第3〜5圖所示’改質區域7係沿著切斷預定線$僅形 成在加工對象物1之內部，藉此改質區域7以形成切斷起 點區域8。本實施形態有關之雷射加工方法，並非使加工 對象物1吸收雷射光L·而發熱，進而形成改質區域7。而 係使雷射光L透射加工對象物1，使加工對象物1之內部 產生多光子吸收以形成改質區域。是於，在加工對象物1 之面10上幾乎不吸收雷射光L，從而加工對象物1之面 1 0不熔融。 於加工對象物1之切斷上，若在要切斷之地點有起點 時則加工對象物1係從該起點分裂，因此’如第6圖所示 ’能以較小力切斷加工對象物1。是於，在加工對象物1 之面10上不會產生不要之分裂而能切斷加工對象物1。 -12- 200914185 且說，本實施形態上，藉多光子吸收而形成之改質區 域有下述之（1)〜（3)之情形。 (1)改質區域含有1個或多個龜裂之龜裂區域之情形： 在基板（例如由藍寶石（saPPhire)、玻璃、或LlTa〇3 作成之壓電材料）之內部，對齊集光點，以集光點上之電 場強度爲lxl〇8(W/cm2)以上且脈衝寬爲1μ$以下之條件照 射雷射光。此脈衝寬之大小係以產生多光子吸收但不會對 基板之面施加不要之損傷，而只在基板之內部產生龜裂區 域爲條件。藉此，在基板之內部產生因多光子吸收所導致 之光學損傷，藉此在基板內部形成龜裂區域。電場強度之 上限値例如係爲lxl〇12(W/cm2)。脈衝寬例如Ins〜200ns 爲最好。 本發明者等藉實驗求出電場強度與龜裂之大小之關係 。實驗條件係如下述。 (A)基板：派勒斯（pyrex)(登錄商標） 玻璃（厚度700μίη) (Β)雷射： 光源：半導體雷射激發Nd ·· YAG雷射 波長：1064nm 雷射光點斷面積：3.14xl0_8cm2 振盪形態：Q切換脈衝（Q switch pulse) 循環頻率：1 00kHz 脈衝寬：3 0 n s 輸出：輸出<lmJ/脈衝 -13- 200914185 雷射光品質：ΤΕΜ00 偏光特性：直線偏光 (C) 集光用透鏡： 對雷射光波長之透射率：60% (D) 載置基板之載置台之移動速度：100mm/秒 另外’所謂雷射光品質TEMoo係指集光性高，能涵 蓋雷射光之波長範圍。 第7圖係示出上述實驗之結果之曲線圖。橫軸係爲尖 峰功率密度，因雷射光係爲脈衝光，故電場強度係用尖峰 功率密度表示。縱軸1係表示藉1個脈衝之雷射光在基板 內部形成之龜裂部份（龜裂點）之大小。集合龜裂點即成龜 裂區域。龜裂點之大小係爲龜裂點之形狀中最大長度之部 份之大小。曲線中以黑圓點表示之資料係集光用透鏡（C) 之倍率爲1〇〇倍，開口數（NA)爲0.80之情形之資料。另 外，曲線中以白圓點表示之資料係集光用透鏡（C)之倍率 爲5 0倍，開口數爲0.5 5之情形之資料。從圖上可知從尖 峰功率密度爲l〇W(W/cm2)程度在基板內部開始產生龜裂 點，隨著尖峰功率密度之增大，龜裂點愈大。 接著，將參照第8〜1 1圖說明在本實施形態有關之雷 射加工上藉龜裂區域之形成造成加工對象物之切斷之機構 。如第8圖所示，以產生多光子吸收之條件，在加工對象 物1之內部對齊集光點P對加工對象物1照射雷射光L而 沿著切斷預定線在內部形成龜裂區域9。龜裂區域9係爲 含有1個或多個之龜裂區域。以此龜裂區域9形成切斷起 -14- 200914185 點區域。如第9圖所示，藉對加工對象物1施加人爲之力 (例如拉伸應力），則以龜裂區域9爲起點（亦即，以切斷 起點區域爲起點）進一步產生龜裂，最終如第10圖所示龜 裂到達加工對象物之上下兩面，進而如第11圖所示，加 工對象物1分裂而切斷。 (2)改善區域係爲熔融處理區域之情形 在基板（例如矽之半導體材料）之內部，對齊集光點， 以集光點上之電場強度爲lxl〇8(W/cm2)以及及脈衝寬爲 1 以下之條件照射雷射光。藉此，基板之內部內因多光 子吸收而被局部加熱。因被加熱，在基板之內部形成熔融 處理區域。所謂熔融處理區域係爲短暫熔融後再固化之區 域，和確係爲熔融狀態之區域，和從熔融狀態再固化之狀 態之區域，也能稱爲相變化之區域和晶體構造變化之區域 。另外，熔融處理區域，在單晶體構造、非晶質構造、多 晶體構造上，係指某構造變化成別的構造之區域。亦即， 例如，自單晶體構造變化成非晶質構造之區域，自單晶體 構造變化成多晶體構造之區域，自單晶體構造在構造上變 化成含有非晶質構造及多晶體構造之區域之意。基板若係 爲矽單晶體構造之情形時熔融處理區域則爲例如非晶質矽 構造。電場強度之上限値例如係爲lxl012(W/Cm2)。脈衝 寬例如Ins〜200ns爲佳。 本發明者藉實驗確認在矽晶圓之內部形成熔融處理區 域。實驗條件係如下述： (A)基板：矽晶圓（厚度3 50μιη，外徑4英吋） -15- 200914185 (B) 雷射： 光源：半導體雷射激發Nd: YAG雷射 波長：l〇64nm 雷射光點斷面積：3.i4xl(T8cm2 振盪形態：Q切換脈衝 循環頻率：1 00kHz 脈衝寬：30ns 輸出：20m"脈衝 雷射光品質：TEM〇〇 偏光特性：直線偏光 (C) 集光用透鏡： 倍率：5 0倍 N.A. ： 0.55 對雷射光波長之透射率：60% (D) 載置基板之載置台之移動速度：100mm/秒 第12圖係表示藉上述條件之雷射加工而被切斷之矽 晶圓之一部份上之斷面之照片之圖。在矽晶圓1 1之內部 形成熔融處理區域13。另外，藉上述條件形成之熔融處 理區域13之厚度方向之大小係爲100 μηι程度。 接著，說明藉多光子吸收形成熔融處理區域1 3。第 1 3圖係表示雷射光之波長與矽基板內部之透射率之關係 之曲線圖。但是，去除矽基板之表面側和裏面側各個反射 成份而僅示出內部之透射率。示出矽基板之厚度t爲 50μηι、ΙΟΟμιη、200μιη、500μιη、ΙΟΟΟμηι 時之上述關係。 -16 - 200914185 例如，Nd : YAG雷射波長係爲1 064nm，若矽基板之 厚度係爲5 00μηι以下之情形時從圖上可知雷射光有80% 以上透射矽基板之內部。第1 2圖所示之矽晶圓1 1之厚度 因係爲350 μηι，故多光子吸收所造成之熔融處理區域13 若形成在矽晶圓11之中心附近時則係形成在距矽晶圓1 1 之表面175 μιη之部份上。這種情形之透射率，若參考厚 度200μιη之矽晶圓時係爲90%以上，被矽晶圓11之內部 吸收之雷射光很少，幾乎全部透射。這情事意味著在矽晶 圓1 1之內部並非吸收雷射光而在矽晶圓1 1之內部形成熔 融處理區域1 3(亦即並非藉雷射光所造成之通常之加熱而 形成熔融處理區域），而是因多光子吸收而形成熔融處理 區域。 另外，矽晶圓以藉熔融處理區域形成之切斷起點區域 爲起點朝斷面方向產生分裂，當此分裂到達晶圓上下之兩 面時即切斷。依發明者等之考察，產生以熔融處理區域與 其它區域在物性上之差異而容易在矽晶圓之內部產生應變 之故。另外，從第12圖所示之照片可瞭解在熔融處理區 域13之上上有存在光頭狀之熔融痕跡。可想像以熔融處 理區域爲起點之龜裂是藉此熔融痕跡，能以較好精確度到 達政晶圓之上下兩面。另外，溶融處理區域僅形成在砂晶 圓之內部，自切斷後之切斷面看，如第12圖所示，得知 僅在內部形成熔融處理區域。在基板內部藉熔融處理區域 形成切斷起點區域後，切斷時不易在切斷起點區域線外產 生不要之分裂，故容易控制切斷。 -17- 200914185 (3)改質區域係爲折射率（index of refraction)變化區域之 情形 在基板（例如玻璃）之內部對齊集光點，以集光點上之 電場強度爲lxl〇8(W/cm2)以上且脈衝寬爲Ins以下之條件 照射雷射光。將脈衝寬作成極窄，使在基板之內部產生多 光子吸收後，因多光子吸收所產生之能量不轉化爲熱能量 ，而在基板內部引起離子價數之變化、結晶化或極化方位 等之永久性之構造變化，進而形成折射率變化區域。電場 強度之上限値例如係爲lxl012(W/cm2)。脈衝寬例如Ins 以下爲佳，但Ins以下更好。 以上，說明了多光子吸收所形成之改質區域（1)〜（3) 之情形，但是若考慮加工對象物之晶圓構造和其之劈開性 等而如下述那樣形成切斷起點區域時則以該切斷起點區域 爲起點，能以更小之力且精確度較佳地切斷加工對象物。 換言之，若是爲由矽等之鑽石構造之單結晶半導體作 成之基板之情形時則沿著（111)面（第1劈開面）和（110)面（ 第2劈開面）之方向形成切斷起點區域爲佳。另外，若是 由GaAs等之閃鋅礦型結構之III-V族化合物半導體作成 之基板時則沿著（1 1 0)面之方向形成切斷起點區域爲佳。 另外，若係爲具有藍寶石（Ahoy等之六方晶系之晶體構 造之基板之情形時則以（000 1 )面（C面）爲主面，沿著 (1120)面（A面）或（11〇〇)面（M面）之方向形成切斷起點區域 爲佳。 另外’若是切斷例如圓盤狀晶圓之基板之情形時如果 -18- 200914185 沿著形成上述切斷起點區域所需之方向（例如沿著單結晶 矽基板上（111)面之方向），或者沿著與形成切斷起點區域 所需之方向正交之方向上，在晶圓上形成取向平坦 (orientation flat)時則以該取向平坦爲基準，藉此，能容 易且正確地在晶圓上形成沿著形成切斷起點區域所需之方 向之切斷起點區域。 下面將參照第1 4圖說明使用於上述之雷射加工方法 之雷射加工裝置。第1 4圖係雷射加工裝置1 0 0之槪略構 成圖。 雷射加工裝置100具備產生雷射光L之雷射光源101 ，爲了調節雷射光L之輸出和脈衝等而控制雷射光源1 〇 1 之雷射光源控制部1 02，具有反射雷射光L之功能且配置 成能將雷射光L之光軸之取向改變90之分色鏡103，對 被分色鏡103反射之雷射光L予以集光之集光用透鏡1〇5 ，載置被經集光用透鏡1 〇5集光後之雷射光照射之加工對 象物1之載置台107，用於將載置台1〇7朝X軸向移動之 X軸台109，將載置台1〇7朝與X軸向正交之Y軸移動之 Y軸台111，用於將載置台1〇7朝與X軸及Y軸向正交之 方向之Z軸向移動之Z軸台113，及控制此三個台1〇9、 1 1 1、1 1 3之移動之台控制部1 1 5。 集光點P在X(Y)軸向上之移動係藉X(Y)軸台 109(111)使加工對象物1朝Χ(Υ)軸向移動而進行。Ζ軸方 向因係爲與加工對象物1之面10垂直之方向，故成爲射 入加工對象物1之雷射光L之焦點深度之方向。是於，藉 -19- 200914185 將z軸台113朝Z軸方向移動，能在加工對象物1之內 部對齊雷射光L之集光點p。 雷射光源1 0 1係爲產生脈衝雷射光之Nd : YAG雷射 。能作爲雷射光源1 0 1之雷射，另外有Nd : YV04雷射， Nd : YLF雷射和鈦藍寶石雷射。本實施形態，對加工對 象物1之加工雖係使用脈衝雷射光，但是只要能引起多光 子吸收的話也可使用連續波雷射光。 雷射加工裝置100另具備用於產生照明被載置於載置 台1 07上之加工對象物1之可視光線之觀察用光源1 1 7， 及配置在與分色鏡103及集光用透鏡105相同光軸上之可 視光用之光束分離器119。分色鏡103係配置在光束分離 器119和集光用透鏡1〇5之間。光束分離器119具有將一 半之可視光線反射，使另外之一半透射之功能，且配置成 將可視光線之光軸之取向改變90。從觀察用光源1 1 7產 生之可視光線約一半被分束分離器119反射，此被反射之 可視光線穿透分色鏡103及集光用透鏡105，而照射含有 加工對象物1之切斷預定線5之面1 0。 雷射加工裝置100另具備光束分離器119，及配置在 與分色鏡103及集光用透鏡105相同之光軸上之攝影元件 121和成像透鏡123。作爲攝影元件121者有例如CCD攝 影機。照射台有切斷預定線5等之面1 0之可視光線之反 射光係穿透集光用透鏡105、分色鏡103、光束分離器 119，在成像透鏡123上成像後被攝影元件121攝影而成 爲攝影資料。 -20- 200914185 雷射加工裝置100另具備輸入攝影元件121 影資料之攝影資料處理部1 2 5，及控制雷射加工 整體之整體控制部127、及監視器129。攝影資料 1 25係根據攝影資料’運算用於使觀察用光源i i 7 可視光之焦點對齊加工對象物1之面1 0之焦點資 著，根據此焦點資料，台控制部11 5移動控制Z ft ，藉此’使可視光之焦點對齊加工對象物1之面 於’攝影資料處理部125係作爲自動聚焦單元而運 外’攝影資料處理部1 2 5係根據攝影資料，運算面 擴大影像等之影像資料。此影像資料然後被送至整 部1 2 7 ’經整體控制部執行各種處理後送到監視器 藉此，在監視器129上顯示擴大影像等。 整體控制部1 2 7輸入來自台控制部1 1 5之資料 影資料處理部1 25之影像資料等，並根據這些資料 雷射光源控制部1 02、觀察用光源丨！ 7及台控制部 藉此，控制雷射加工裝置1 00。是於，整體控制部 作爲電腦單元而運作。 下面將說明使用上述雷射加工裝置100之本實 有關之雷射加工方法。第15圖係表示在本實施形 之雷射加工方法上屬於加工對象物之晶圓1 a之斜 另外’第16圖係第15圖所示之晶圓1&之底面圖 ’第17圖係表示第16圖所示之晶圓ia之VI-VI VII斷面之擴大圖。 參照第15〜17圖，晶圓la係爲平板約呈圓盤 '出之攝 置 100 _處理部 產生之 料。接 & 台 1 13 10。是 作。另 i 1 〇之 體控制 129。 ，及攝 ，控制 115， 127係 施形態 態有關 視圖。 。另外 及 VII- 狀。參 -21 - 200914185 照第16圖，其示出在晶圓la之裏面21上設定有縱橫地 交叉之多數切斷預定線5。切斷預定線5係爲用於將晶圓 1 a切斷成多數之晶片狀部份之推定假想線。此切斷預定 線5也可沿著例如1 a之劈開面推定。 另外，晶圓la具有取向平坦（以下稱爲「OF」）19。 本實施形態，OF 1 9係將與縱橫地交叉之切斷預定線5中 之一個方向平行之方向作爲長邊方向而形成。OF19設置 之目的係當沿著切斷預定線5切斷晶圓之際容易判別切斷 方向。 另外，參照第17圖，晶圓la具備由半導體（Si)作成 之基板15，及疊置在基板15之表面6上之疊層部4。疊 層部4具有由絕緣性材料（Si02)作成之層間絕緣層17a及 17b，以及由金屬（W)作成之第1配線層19a及第2配線層 19b。層間絕緣層17a係疊積在基板15之表面16上，在 表面6上多數相互分割設定之元件形成區域上有疊積第1 配線層19a。第1配線層19a及基板15係藉貫通層間絕 緣層17a之柱塞20a而相互作電氣之連接。層間絕緣層 1 7b係疊積在層間絕緣層1 7a及第1配線層1 9a上，在屬 於層間絕緣層1 7b上’對應第1配線層丨9a之區域有疊積 在第2配線層1 9b。第2配線層1 9b及第1配線層19a係 藉貫通層間絕緣層1 7b之柱塞20b而相互作電氣之連接。 在屬於層間絕緣層1 7 b上，位在第2配線層1 9 b之間 之間隙之區域係被推定爲切斷預定線5。於此切斷預定線 5上，層間絕緣層1 7b之表面（亦即，晶圓1 a之表面3)係 -22- 200914185 平坦且光滑。 (第1實施例） 第1 8及1 9圖係用於說明本實施形態有關之雷射加工 方法之第1實施例之流程圖。另外，第20〜22圖係用於 說明本實施例有關之雷射加工方法之晶圓1 a之斷面圖。 參照第18圖，首先在晶圓la之表面3上安裝保護帶 25以作爲保護疊層部4之保護膜（S1，第20A圖）。保護 帶25之材料只要具有保護疊層部4之緩衝效果，對疊層 部4之動作特性無影響的話任何材料皆可使用。本實施形 態係選擇除了吸收衝擊外另能藉紫外線之照射予以去除之 材料作爲保護帶2 5之材料。 接著，於晶圓1 a之基板1 5之內部沿著切斷預定線5 形成切斷起點區域8(S3，第20B圖）。這裡，第20B圖所 示之晶圓la係被描繪成表面3係在圖之下方。換言之， 將對應晶圓la之裏面21上之切斷預定線5之區域作爲雷 射光入射面，對基板1 5之內部之集光點p照射雷射光， 藉此在基板15之內部形成熔融處理區域13以作爲改質區 域。此熔融處理區域1 3在進行切斷晶圓之際係作爲切斷 起點區域8。 這裡，第19圖係表示使用第14圖所示之雷射加工裝 置100，在晶圓la上形成切斷起點區域8之方法之流程 圖。另外，本實施形態上，晶圓1 a係在雷射加工裝置 1〇〇之載置台107上配置成裏面21係與集光用透鏡105 -23- 200914185 成對向。亦即，雷射光L係射入晶圓1 a之裏面2 1。 參照第14及19圖，首先，藉未圖示之分光光度計等 測定基板1 5之光吸收特性。根據此測定結果，選定產生 對基板1 5係透明之波長或者吸收少之波長之雷射光L之 雷射光源101(S101)。 接著，考慮基板15之厚度，材質及折射率等，決定 晶圓la在Z軸方向之移動量（S103)。這是爲了在使雷射 光L之集光點P對齊距晶圓la之裏面21既定距離內側之 所要位置，以位在晶圓1 a之裏面2 1之雷射光L之集光點 P爲基準而在晶圓laZ之Z軸方向上之移動量。此移動量 係輸入整體控制127。 將晶圓la在雷射加工裝置100之載置台107上配置 成使晶圓1 a之裏面2 1與集光用透鏡1 05側成對向。這時 ，設有疊層部4之晶圓表面3因有安裝保護帶25，故即 使將晶圓1 a之表面3側朝下載置於載置台1 07，也不會 有任何問題。又，自觀察用光源1 1 7產生可視光以照明晶 圓la之裏面21(S105)。被照明之晶圓la之裏面21係被 攝影元件1 2 1攝影。被攝影元件1 2 1攝影之攝影資料是送 至攝影資料處理部125。根據此攝影資料，攝影資料處理 部125運算觀察用光源117之可視光之集點能位在晶圓 la之裏面21之焦點資料（S107)。 此焦點資料係被送至台控制部1 1 5。台控制部1 1 5則 根據此焦點資料使Z軸台1 13在Z軸方向上移動（S1 09)。 藉此，使觀察用光源117之可視光之焦點位在晶圓la之 -24- 200914185 裏面21。另外，攝影資料處理部125根據攝影資料，運 算含有切斷預定線5之裏面21之擴大影像資料。此擴大 影像資料則經整體控制部1 27而被送至監視器1 29，藉此 將切斷預定線5附近之擴大影像顯示在監視器129上。 整體控制部127輸入事先在步驟S1 03上決定之移動 量資料，然後將此移動量資料送至台控制部1 1 5。台控制 部1 1 5則根據此移動量資料，藉Z軸台1 1 3使晶圓1 a朝 Z軸方向移動俾使雷射光L之集光點P之位置位在距晶圓 la之裏面21既定距離之內側（Sill)。 接著，自雷射光源1 01產生雷射光L，使雷射光L照 射到晶圓1 a之裏面2 1。雷射光L之集光點P因係位在基 板1 5之內部，故係爲改質區域之溶融處理區域1 3僅形成 在基板1 5之內部。又，使X軸台10 9和Y軸台1 1 1沿著 切斷預定線5移動以形成多個熔融處理區域13，或沿著 切斷預定線5連續形成熔融處理區域13，藉此，在基板 15之內部形成沿著切斷預定線5之切斷起點區域8(S 11 3) 〇 再度梦照弟18圖，在晶圓la之裏面21上安裝屬於 延展性薄膜之延展帶23(S5，第20C圖）。延展帶23係由 例如在伸展方向上加力而能伸展之材料所作成，係在爾後 之作業上用於將晶圓la分離成晶片狀。延展帶23除了係 爲在伸展方向加力而伸展之物外，也可係爲例如能藉加熱 而伸展之物。 接著，沿著切斷起點區域8將晶圓1 a切斷成多數之 -25- 200914185 晶片狀部份24(S7 ’第21A圖）。亦即，用刀口自安裝在 晶圓la裏面21之延展帶23上面抵著切斷起點區域8, 藉對晶圓1 a施加彎曲應力，進而以切斷起點區域8作爲 起點而割斷（分離）晶圓la。這時，在晶圓la內部自切斷 起點區域8闊始產生達及表面3及裏面21之龜裂18，從 而切斷基板15之同時也切斷層間絕緣層17a及17b。作 爲對晶圓1 a施加應力之措施，除了刀口 3 3外，另外，例 如，分裂裝置、輥裝置等。另外，也可用不會引起晶圓 1 a表面3和裏面2 1等表面產生熔融之能量，但能被晶圓 1 a吸收之雷射光照射晶圓使產生熱應力而以切斷起點區 域8爲起點產生龜裂而予以切斷。另外，也可自安裝在晶 圓la之表面3上之保護帶25上方以刀口等抵住，進而施 加彎曲應力。 接著，對安裝在晶圓la表面3上之保護帶25照射紫 外線V(S9，第21B圖）。藉對保護帶25照射紫外線V使 保護帶25處於可除去之狀態。然後，自晶圓la之表面3 將保護帶25剝離（S11，第21C圖）。另外’也可在切斷晶 圓la(S7)之前剝離保護帶25。 接著，將晶圓la分離成各爲晶片狀之部份24(S 13， 第22圖），亦即，使延展帶23伸展藉以在多數之晶片狀 部份24之間產生間隔2 6。藉作成這樣’能易於拾取多數 晶片狀部份24之各個晶片。 如上所說明，本實施例有關之雷射加工方法’藉在晶 圓1 a之表面3上安裝保護帶2 5 ’能將晶圓1 a以裏面朝 -26- 200914185 上載置於載置台1 07，因此，能較佳地自晶圓1 a之裏面 2 1對基板1 5之內部照射雷射光L。 又’藉所謂多光子吸收現象形成改質區域，在基板 15之內部形成沿著用於切斷晶圓ia所要之切斷預定線5 之切斷起點區域8。另外，在晶圓la之裏面21上安裝延 展帶23，藉伸展此延展帶23，能容易地分離切斷之晶圓 la之多數晶片狀部份24。 亦即，依本實施例有關之雷射加工方法，能不直接對 位在晶圓la之表面3之疊層部4照射雷射光L而形成切 斷起點區域8，因此能防止雷射光L對疊層部4所造成之 損傷。另外，藉在基板15內部形成切斷起點區域8，能 以切斷起點區域8爲起點以較小且較佳精確度切割晶圓 la，並能容易地分離切斷之晶圓。因此，依此雷射加工方 法，即便晶圓1 a具有疊層部4之情形也能以高精確度切 斷晶圓1 a。 另外，依本實施例有關之雷射加工方法，相較於以往 之刀切法等能使晶片狀部份24間之切割寬度格外的小。 如此縮小切割寬度，能減小各個晶片狀部份24之間之間 隔，進而能得出更多之晶片狀部份24。 另外，依疊層部4之構成材料和雷射光L之照射條件 ，有必要考慮雷射光L不照射疊層部4之元件形成區域。 特別是本方法，爲了利用多光子吸收現象而急劇地將雷射 光收斂，因此，雖然是達成雷射光L不照射疊層部4之形 成區域，但也有不容易自表面3照射雷射光之情形。另外 -27- 200914185 ，一般在晶圓元件形成區域間大多存在元件用之疊層半 體層。或者，記憶體和積體電路元件等上也有在元件形 區域間形成TEG(Test Element Group:試驗元件群）等 功能元件。這樣的情形，若使用本發明有關之雷射加工 法時能從未設置疊層部4之裏面21照射雷射光，從而 基板1 5之內部較佳地形成切斷起點區域8。 另外，本實施例有關之雷射加工方法係藉用刀口等 晶圓1 a施加外力，以切斷起點區域8爲起點將晶圓1 a 斷成多數晶片狀部份24。藉此，以切斷起點區域8爲 點能容易切斷晶圓1 a。 另外，本實施例有關之雷射加工方法係將延展帶 安裝於晶圓1 a後才除去保護帶2 5。藉此，能把持形成 斷起點區域8之晶圓1 a，使不玫離散成各個晶片狀部 24。 第23圖係用於說明本實施例有關之雷射加工方法 變更例之斷面圖。本變更例係在基板15之內部，於基 15之厚度方向形成多數之熔融處理區域13。欲這樣地 成熔融處理區域13，只要交互地多次執行第19圖所示 流程圖之步驟S 1 1 1 (在Z軸方向上移動晶圓）和步驟S 1 1 形成改質區域）即可。另外’也可同時執行在Z軸方向 移動晶圓la和形成改質區域’藉此在基板之厚度方向 連續地形成熔融處理區域13。 如本實施例，藉形成熔融處理區域1 3，能形成在 板15之厚度方向上延伸之切斷起點區域8。因此’能 導 成 之 方 在 對 切 起 23 切 份 之 板 形 之 3( 上 上 基 以 -28- 200914185 更小之力切割晶圓1 a。另外，若在基板1 5之厚度方向上 生長因熔融處理區域1 3所造成之龜裂，則不必借助外力 即能分離晶圓1 a。 (第2實施例） 第24圖係表示本實施形態所執行之雷射加工方法之 第2實施例之流程圖。另外，第25〜27圖係用於說明本 實施例之晶圓la之斷面圖。本實施例與上述之第1實施 例不同之點係（1)將基板15硏磨薄，（2)不用刀口 33等以 行分裂，及（3)在將晶圓la分離成多數之晶片狀部份24 後將保護帶25剝離，第三點。 參照第24圖，首先在晶圓la之表面3上安裝保護帶 25(S21，第25A圖）。此作業係與第1實施例上之步驟S1 相同，因此省略其詳細說明。 接著’硏磨晶圓la之裏面21(S23，第25B圖）。這 時’將基板15之厚度硏磨到例如30μιη〜50μιη之薄。另 外’其次之作業也可硏磨裏面21使硏磨後之裏面21成平 坦且光滑俾較佳地使雷射光L自裏面2 1射入。 接著，在晶圓1 a之基板15之內部，沿著切斷預定線 5形成切斷起點區域8(S25，第25C圖）。接著，在硏磨晶 圓la後將延展帶23安裝於裏面21(S27，第26A圖）。這 些作業分別與上述第1實施例之步驟S3及S5相同，因此 省略其等之詳細說明。 接著’使延展帶23伸展，藉此以切斷起點區域8爲 -29- 200914185 起點將晶圓1 a切斷成多數晶片狀部份24，另同時使各個 晶片狀部份24相互分離（S29，第26B圖）。這時，因爲在 前述之步驟S23上基板15已被充份地硏磨薄化，故僅藉 延展帶23之伸展所產生之拉伸應力，以切斷起點區域8 爲起點切斷晶圓1 a。又，使延展帶23如此保持伸展，使 多數晶片狀部份24之間拉開一個間隔26。 接著，對保護帶25照射紫外線（S31，第26C圖），將 保護帶25自晶圓la之表面3剝離（S33，第27圖）。這些 作業因係分別與上述第1實施例之步驟S 9及S 1 1相同， 故省略其等之詳細說明。另外，也可在使延展帶23伸展 而切斷晶圓la之作業（S29)之前剝離保護帶25。 本實施例有關之雷射加工方法係與上述之第1實施例 相同，不對設在晶圓1 a之表面3之疊層部4直接照射雷 射光L而能形成切斷起點區域8，因此能防止因雷射光L 所造成之疊層部4之損傷。另外，藉在基板15內部形成 切斷起點區域8，能以切斷起點區域8爲起點以較小且較 佳精確度割斷晶圓1 a，容易分離被切斷之晶圓1 a。因此 ’依雷射加工方法，即便是晶圓1 a上有疊層部4之情形 時也能以高精確度切斷晶圓1 a。 另外’本實施例有關之雷射加工方法係硏磨晶圓la 之裏面21以薄化晶圓1 a之基板1 5。藉此，能以切斷起 點區域8爲起點以較小之力或不需特別之力切斷晶圓j a 。另外’相較於基板1 5之厚度較厚之情形，能以更好之 精確度切斷晶圓la。 -30- 200914185 另外，本實施例有關之雷射加工方法，使安裝於晶圓 la之裏面21上之延展帶23伸展，藉此，以切斷起點區 域8爲起點將晶圓1 a切斷成多數之晶片狀部份24，同時 使多數之晶片狀部份24相互分離。在使延展帶23伸展之 際拉伸應力係加於晶圓1 a之切斷起點區域8，因此，能 以切斷起點區域8爲起點較佳地切斷晶圓la。因此，依 本實施形態能同時進行切斷晶圓1 a之作業和將晶圓1 a相 互分離成多數晶片狀部份24之作業，因此能減少製造作 業。 另外，本實施例有關之雷射加工方法係將晶圓1 a之 裊面21作爲雷射光入射面照射雷射光L。依本發明者之 實驗，熔融處理區域13等之改質區域在基板15內部有偏 向雷射光入射面側形成之傾向。因此，本雷射加工方法， 切斷起點區域13有偏向安裝延展帶23之裏面21側形成 之傾向。另外，使延展帶23伸展時施加之拉伸應力在基 板15之裏面21附近係比表面6附近大。因此，在基板 1 5之內部，切斷起點區域8若偏向裏面2 1側時則能藉延 展帶25之伸展，使拉伸應力更有效果地作用於切斷起點 區域8。由上述，依本實施例有關之雷射加工方法，能使 拉伸應力更有效地作用於切斷起點區域，進而能以更小之 力切斷晶圓1 a。 另外’本實施例有關之雷射加工方法，在藉延展帶 23之伸展將晶圓1 a分離成多數之晶片狀部份24後才除 去保護帶25。藉此，在切斷晶圓1 a後到取出多數之晶片 -31 - 200914185 狀部份24止之期間，能保護多數之晶片狀部份24。 (第3實施例） 第28圖係表示本實施形態所執行之雷射加工方 第3實施例之流程圖。本實施例與上述第1實施例不 點僅係不用刀口 3 3等進行分裂一點。本變更例將參 1實施例上所示之第20〜22圖進行說明。 參照第28圖，首先在晶圓la之表面3上安裝保 25(S41，第20A圖）。接著，在晶圓la之基板15內 著切斷預定線5形成切斷起點區域8(S43，第20B 接著，在晶圓la之裏面21上安裝延展帶23(S45，第 圖）。這些作業因係分別與上述之第1實施例之步驟 S5相同，故省略其等之詳細說明。 接著，對保護帶25照射紫外線（S47，第21B圖: 保護帶25自晶圓la之表面剝離（S49，第21C圖）。 作業係分別與上述之第1實施例之步驟S 9及S 1 1相 因此省略其等之詳細說明。但是，本變更例因無採用 33所施加之應力，故無產生第21B及21C圖所示之 18° 接著，藉由伸展延展帶23，以切斷起點區域8 點’將晶圓la切斷成多數晶片狀部份24，同時使各 片狀部份24相互分離（S51，第22圖）。這時，本實 因不似第2實施例那樣將基板1 5硏磨薄化，故係以 2實施例者大之延展帶之伸展所產生之拉伸應力，以 法之 同之 照第 護帶 部沿 圖）° 20C S 1〜 ，將 這些 同。 刀口 龜裂 爲起 個晶 施例 比第 切斷 -32- 200914185 起點區域8爲起點切斷晶圓1 a。又，使延展帶2 3保持伸 展，可使多數晶片狀部份24之間拉開一間隔26。 本實施例有關之雷射加工方法，藉與上述之第1實施 例相同理由，即便是晶圓1 a具有疊層部4之情形，也能 以高精確度切斷晶圓1 a。 另外，本實施例有關之雷射加工方法係與上述第2實 施例者相同地，藉由伸展延展帶23，以切斷起點區域8 爲起點，將晶圓1 a切斷多數之晶片狀部份24，同時使多 數之晶片狀部份相互分離。藉此，切斷晶圓1 a之作業和 使多數之晶片狀部份24相互分離之作業能同時進行，進 而能減少製造作業。 (第4實施例） 第29圖係表示本實施形態所執行之雷射加工方法之 第4實施例之流程圖。本實施例與上述之第1實施例不同 之點係僅爲硏磨薄化基板1 5這點。本變更例將參照第1 實施例上所示之第20〜第22圖和第2實施例上所示之第 2 5圖進行說明。 參照第29圖，首先，在晶圓la之表面3上安裝保護 帶25(S61 ’第20A圖）。此作業因係與第1實施例上之步 驟S1相同’故省略其詳細說明。接著，硏磨晶圓1 &之裏 面21(S63，第25B圖）。此作業因係與第2實施例上之步 驟S23相同，故省略其詳細說明。接著，在基板15之內 部沿著切斷預定線5形成切斷起點區域8(S65，第25C圖 -33- 200914185 )。此作業因係與第1實施例之步驟S3相同，故省略其詳 細說明。 接著，在晶圓la之裏面21安裝延展帶23(S67，第 20C圖），藉施加外力於晶圓1 a上，沿著切斷起點區域8 將晶圓la切斷成多數之晶片狀部份24(S69，第21A圖） ，接著，對保護帶2 5照射紫外線（S 7 1，第2 1 B圖），自晶 圓la表面3剝離保護帶25(S73，第21C圖），藉延展帶 23之伸展，使晶圓1 a之各個晶片狀部份24相互分離 (S 75，第22圖）。這些作業因係分別與上述第1實施例之 步驟S 5〜S 1 3相同，故省略其等之詳細說明。但是，本實 施例係在步驟S 6 3上硏磨晶圓1 a之裏面2 1，故基板1 5 之厚度係比第20C圖、第21A〜21C圖、及第22圖所示 之基板15薄。另外，也可在進行切斷晶圓la(S69)之前剝 離保護帶25。 本實施例有關之雷射加工方法藉與上述第1實施例相 同之理由，即便是晶圓1 a有疊層部4之情形，也能以高 精確度切斷晶圓la。 另外，本實施例有關之雷射加工方法係與第2實施例 相同，硏磨晶圓1 a之裏面2 1以薄化晶圓1 a之基板1 5。 藉此，能用較小之刀’或不必藉特別之力即能以切斷起點 區域8爲起點，高精確度切斷晶圓1 a。 另外，本實施例有關之雷射加工方法係與第1實施例 相同地，藉施加外力’以切斷起點區域8爲起點，將晶圓 1 a切斷成多數之晶片狀部份2 4。藉此，以切斷起點區域 -34- 200914185 8爲起點，容易地切斷晶圓ia。 以上’雖已詳細說明本發明之實施形態及實施例，但 本發明並不限定於上述實施形態及實施例自不待言。 例如’在上述之實施形態及實施例上雖係使用半導體 基板作爲基板，但本發明不限定於半導體基板，也能較佳 地應用於具有導電性基板，和絕緣性基板之情形。 (產業上之利用可能性） 如上述’依本發明有關之雷射加工方法，藉在加工對 象物之表面安裝保護膜，能將加工對象物以裏面朝上載置 於載置台上’因此能較佳地自加工對象物之裏面對基板之 內部照射雷射光。又’以藉所謂多光子吸收之現象形成之 改質區域’沿著所要之切斷預定線，在基板內部形成切斷 加工對象物所需之切斷起點區域，進而能以切斷起點區域 爲起點切斷加工對象物。又，在加工對象物之裏面安裝延 展性薄膜’藉伸展此延展性薄膜，能容易地分離被切斷之 加工對象物之多數部份。亦即，依本雷射加工方法，能不 直接對位在加工對象物之表面之疊層部照射雷射光而形成 切斷起點區域’同時能以切斷起點區域爲起點用較小之力 ，精確度較佳地割斷加工對象物，能容易地分離被切斷之 加工對象物。因此，依此雷射加工方法，即便是加工對象 物具有各種之疊層構造之情形，也能以高精確度切斷該加 工對象物。 -35- 200914185 【圖式簡單說明】 第1圖係本實施形態有關之雷射加工方法所執行之雷 射加工中之加工對象物之平面圖。 第2圖係沿著第1圖所示之加工對象物之11線之 斷面圖。 第3圖係本實施形態有關之雷射加工方法所執行之雷 射加工後之加工對象物之平面圖。 第4圖係沿著第3圖所示之加工對象物之IV-IV線之 斷面圖。 第5圖係沿著第3圖所示之加工對象物之V -V線之 斷面圖。 第6圖係本實施形態有關之雷射加工方法執行切斷後 之加工對象物之平面圖。 第7圖係表示本實施形態有關之雷射加工方法上之電 場強度與龜裂點大小之關係之曲線圖。 第8圖係本實施形態有關之雷射加工方法之第1作業 之加工對象物之斷面圖。 第9圖係本實施形態有關之雷射加工方法之第2作業 之加工對象物之斷面圖。 第1 0圖係本實施形態有關之雷射加工方法之第3作 業之加工對象物之斷面圖。 第1 1圖係本實施形態有關之雷射加工方法之第4作 業之加工對象物之斷面圖。 第1 2圖係表示藉本實施形態有關之雷射加工方法切 -36- 200914185 斷之矽晶圓之一部份之斷面之照片之圖。 第1 3圖係表示本實施形態有關之雷射加工方法雷射 光之波長與矽基板之內部之透射率之關係之曲線圖。 第1 4圖係本實施形態有關之雷射加工裝置之槪略組 成圖。 第1 5圖係表示在本實施形態有關之雷射加工方法上 使用之晶圓之斜視圖。 第16圖係第15圖所不晶圓之平面圖。 第17圖係表示第16圖所示之晶圓之VI-VI斷面及 VII-VII斷面之擴大圖。 第1 8圖係用於說明本實施形態有關之雷射加工方法 及第1實施例之流程圖。 第19圖係表示使用第14圖所示之雷射加工裝置在晶 圓形成切斷起點區域之方法之流程圖。 第20A〜20C圖係用於說明第1實施例有關之雷射加 工方法之晶圓之斷面圖。 第21A〜21C圖係用於說明第1實施例有關之雷射加 工方法之晶圓之斷面圖。 第22圖係用於說明第1實施例有關之雷射加工方法 之晶圓之斷面圖。 第23圖係用於說明第1實施例有關之雷射加工方法 之變更例之斷面圖。 第2 4圖係用於說明本實施形態有關之雷射加工方法 之第2實施例之流程圖。 -37- 200914185 第25 A〜25C圖係用於說明第2實施例有關之雷射加 工方法之晶圓之斷面圖。 第26 A〜26C圖係用於說明第2實施例有關之雷射加 工方法之晶圓之斷面圖。 第27圖係用於說明第2實施例有關之雷射加工方法 之晶圓之斷面圖。 第2 8圖係用於說明本實施形態有關之雷射加工方法 上之第3實施例之流程圖。 第2 9圖係用於說明本實施形態有關之雷射加工方法 上之第4實施例之流程圖。 【主要元件符號說明】 1 :加工對象物 1 a :晶圓 3 :表面 4 :疊層部 5 :切斷預定線 6 :晶圓之表面 7 :改質區域 8 :切斷起點區域 9 :龜裂區域 1 〇 :加工對象物1之面 1 3 :熔融處理區域 1 5 :基板 -38- 200914185 1 7 a :層間絕緣層 1 9 a :第1配線層 2 0 a :柱塞 21 :晶圓之裏面 23 __延展帶 25 :保護帶 1 〇 〇 :雷射加工裝置 1 〇 1 __雷射光源 102 ‘·雷射光源控制部 1 0 3 :分色鏡 1 〇 5 :集光用透鏡 107 :載置台 1 0 9 : X軸台 1 1 1 : Y軸台 1 13 : Z軸台 1 1 5 :台控制部 119 :光束分離器 1 2 1 :攝影元件 1 2 3 :成像透鏡 125 :攝影資料處理部 127 :整體控制部 1 2 9 :監視器BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method, particularly a laser using a prior art. In recent years, a semiconductor operating layer having a crystal growth method or the like on an Al 2 〇 3 substrate has been used as a In the semiconductor device, a glass substrate or the like is used as a liquid crystal display device, and the object to be processed is cut by high precision. The knife cut method (b 1 ade - dicing) and the diamond scribe method are used. The knife cutting method is a method of cutting an object by a diamond blade or the like. The diamond engraving method is to cut the object by pressing the diamond tip tool (diamond ρι draws the line on the surface of the object, and then 7 edge) along the scribe 1 ine. A method of processing an object. However, in the case of the knife cutting method, for example, when the object to be processed is used, the crystal display device may have a gap between the glass substrate and the other glass, and there may be a cutting layer and a lubricating water entering the room. In the case of the engraving method, when the substrate of the object having a high hardness such as Al2〇3 substrate is processed, or the method of growing the GaN substrate by the force-machining method is increasingly edging, generally (diamond cutting side) Int tool) □ (In the inside of the knife, the gap between the liquid crystal substrates is the same. If the object is bonded to the glass substrate of 200914185, the surface of the object should be drawn not only on the surface of the object to be processed. The line is drawn so that the line drawn on the surface and the inside is deviated due to the positional deviation. [Invention] Therefore, the present invention has been made in view of the above circumstances, and its object is to provide A laser processing method capable of solving the above-described problems and capable of cutting a workpiece with high precision even if the object to be processed has various laminated structures. According to a laser processing method of the present invention, a laser processing method for cutting a flat object including a substrate and a laminated portion provided on the substrate includes the following operation: a protective film is mounted on the surface of the laminated portion; the inside of the object to be processed is used as a laser light incident surface, and the light collecting point is irradiated to the inside of the substrate to irradiate the laser light, thereby forming a modified region generated by multiphoton absorption; a cutting area along which a cutting line is formed along the planned cutting line of the object to be irradiated; a starting point region is formed inside the predetermined distance from the incident surface of the laser light; a ductile film is attached to the inside of the object to be processed; and the cutting starting point region is used as a starting point. The laser beam processing method according to the present invention is a method of cutting a semiconductor substrate and a laminate portion provided on the semiconductor substrate. A laser processing method for a flat object to be processed, comprising the step of: mounting a protective film on a surface of a laminated portion side of the object to be processed; The inside of the object to be processed serves as a laser light incident surface, and the inside of the semiconductor substrate is aligned with the spotlight -6 - 200914185 to emit a laser beam to form a molten processed region; thereby, the molten processed region is along the cutting line of the object to be processed. a cutting start region is formed on the inner side of the predetermined distance of the laser light incident surface; a ductile film is attached to the inside of the object to be processed; and a majority of the stretched film is cut by cutting the starting point region as a starting point According to these laser processing methods, a protective film is attached to the surface of the object to be processed, whereby the inside of the object can be placed on the stage, so that it can be processed from the object to be processed. In the inside of the object, the laser light is preferably irradiated inside the (semiconductor) substrate. Further, the modified region (melted processing region) formed by the multiphoton absorption phenomenon is formed inside the substrate to cut the object to be processed. The cutting start point region of the planned cutting line is cut, and the object to be processed can be cut by using the cutting starting point region as a starting point. Further, a ductile film is attached to the inside of the object to be processed, and by stretching the film, most of the object to be cut can be easily separated. In other words, according to the laser processing method, in addition to not directly aligning the laminated portion on the surface of the object to be irradiated with laser light, a cutting starting point region can be formed, and the cutting starting point region can be used as a starting point with a small force and The substrate is cut with good precision, and the object to be cut can be easily separated. Therefore, according to this laser processing method, even when the object to be processed has various laminated structures, the object to be processed can be cut with high precision. Here, the laminated portion on the substrate refers to a substance stacked on the surface of the substrate, adhered to the surface of the substrate, or mounted on the surface of the substrate, and whether or not the material or the same material is different from the substrate. Further, the laminated portion may be provided in close contact with the substrate, or may be provided with a gap from the substrate. 200914185 Examples thereof include a semiconductor operation layer formed by crystal growth on a substrate, and another glass substrate adhered to a glass substrate. The laminate portion also includes a plurality of layers of different materials. The internal structure of the substrate also includes the meaning of the surface of the substrate on which the laminated portion is provided. In addition, the so-called light collecting point is a place where laser light is collected. Further, the cutting start region may be formed by continuously forming a modified region, and may be formed by intermittently forming a modified region. Further, the laser processing method according to the present invention is a laser processing method for cutting a flat object to be processed including a substrate and a laminated portion provided on the substrate, and the method includes the following operations: a protective film is mounted on the surface of the laminated portion of the object; the inside of the object to be processed is used as a laser light incident surface, and the light collecting point is irradiated to the inside of the substrate to irradiate the laser light to form a modified region due to multiphoton absorption; The modified region forms a cutting start region on the inner side of the predetermined distance from the incident surface of the laser light along the line to be cut of the object to be processed; a ductile film is attached to the inside of the object to be processed; and an external force is applied and cut by the object to be processed The starting point region is a starting point for cutting the object to be cut into a plurality of portions, and the ductile film is stretched to separate most of the object to be processed. Further, the laser processing method according to the present invention is a laser processing method for cutting a flat object including a substrate and a laminated portion provided on the substrate, and the feature includes the following work: a surface of the object on the side of the laminated portion is provided with a protective film; the inside of the object to be processed is used as a laser light incident surface, and the light collecting point is irradiated to the inside of the substrate to irradiate the laser light to form a modified region generated by multiphoton absorption; In the modified region, a cutting starting point -8-200914185 is formed on the inner side of the predetermined distance from the incident surface of the laser light along the cut of the object to be processed; a ductile film is attached to the inside of the object to be processed; and an external force is applied to the object to be processed' The object to be processed is cut into a plurality of portions starting from the cutting starting point region; and the ductile film is stretched to separate most of the object to be processed. In the laser processing method, the same reason as in the above-described laser processing method is described, and the object to be processed can be cut with high precision even when the object to be processed has various laminated structures. In addition, when the object to be processed is cut into a plurality of parts, an external force is applied to the object to be processed, and the object to be processed can be easily cut with the cutting starting point region as a starting point. Further, the laser processing method according to the present invention is a laser processing method for cutting a flat object including a substrate and a laminated portion provided on the substrate, and the feature includes the following work: a surface of the object on the side of the laminated portion is provided with a protective film; the inside of the object to be processed is used as a laser light incident surface, and the light collecting point is irradiated to the inside of the substrate to irradiate the laser light to form a modified region generated by multiphoton absorption; In the modified region, a cutting starting point region is formed on a side of a predetermined distance from the incident surface of the laser light along the line to be cut of the object to be processed; a ductile film is attached to the inside of the object to be processed; and the ductile film is stretched; The object to be processed is cut into a plurality of portions starting from the cutting start region, and at the same time, most of the processed object is separated. Further, the laser processing method according to the present invention is a laser processing method for cutting a flat object including a semiconductor substrate and a laminated portion provided on the semiconductor substrate, and the method includes the following operations: a surface-mounted protective film on the side of the laminated portion of the object to be processed; and a laser light incident surface of the object to be processed -9-200914185 is irradiated with laser light to align the light collecting point inside the semiconductor substrate to form a molten processed region; The molten processed region forms a cutting start region on the inner side of the predetermined distance from the laser light incident surface along the line to be cut of the object to be processed; a ductile film is attached to the inside of the object to be processed; and the ductile film is stretched thereby The object to be processed is cut into a plurality of portions starting from the cutting start region, and at the same time, a majority of the object to be processed is separated. According to the above-described laser processing method, the object to be processed can be cut with high precision even when the object to be processed has various laminated structures. Further, by stretching the ductile film, the stretching of the starting point region of the object to be processed is performed, so that the work of cutting the object to be processed and the separation of a large portion can be performed at the same time, and the manufacturing operation can be reduced. Further, in the above-described laser processing method according to the present invention, it is preferable to honing the inside of the object to be processed before the cutting starting point region is formed on the object to be processed. In this way, the object to be processed can be accurately cut with the cutting force starting point region as a starting point with little or no special force. Further, in the above-described laser processing method according to the present invention, it is preferable to remove the protective film after attaching the ductility film to the object to be processed. Thereby, the object to be processed which forms the cutting start region can be held so as not to be discrete. Alternatively, the stretch film is preferably stretched to separate the protective film by separating a majority of the object to be processed. Thereby, the majority portion can be protected from the time of cutting the object to be processed until the majority is taken out. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Best Mode for Carrying Out the Invention) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The laser processing method according to the present embodiment forms a modified region generated by multiphoton absorption inside the object to be processed. Therefore, the present laser processing method first specifically describes multiphoton absorption. The photon energy hv is optically transparent if it is smaller than the absorption band gap Eg of the material. Therefore, the condition for generating absorption on the material is hv > EG. However, even if it is optically transparent, if the intensity of the laser light is very large, the absorption of the material is caused by the condition of nhv > EG = 2, 3, 4, .... This phenomenon is called multiphoton absorption. In the case of a pulse wave, the intensity of the laser light is determined by the power peak density (W/cm2) of the laser spot, for example, the peak power density is lxl 〇 8 (W/cm 2 ) or more. Conditions will produce multiphoton absorption. The peak power density is obtained from (the energy of each pulse of the laser light at the collection point) + (the beam spot area of the laser beam is X pulse width). Further, in the case of a continuous wave, the intensity of the laser light is determined by the electric field intensity (W/cm2) of the light collecting point of the laser light. Next, the principle of laser processing according to this embodiment using such multiphoton absorption will be described with reference to Figs. 1 to 6 . Fig. 1 is a plan view of the object 1 to be processed in laser processing, and Fig. 2 is a sectional view taken along line 11-II of the object 1 shown in Fig. 1, and Fig. 3 is after laser processing. A plan view of the object 1 to be processed, FIG. 4 is a cross-sectional view taken along the line IV-IV of the object 1 shown in FIG. 3, and FIG. 5 is a view of the object 1 shown in FIG. A cross-sectional view of the VV line, and Fig. 6 is a plan view of the object 1 to be processed -11 - 200914185. As shown in Fig. 1 and Fig. 2, the cutting target line 5 required for cutting the object 1 is cut on the surface 1 of the object 1 to be processed. The cutting planned line 5 is an imaginary line extending linearly (the object 1 can be actually drawn as a line to cut 5). In the laser processing system according to the present embodiment, the laser beam L is irradiated to the object 1 by the collimation point p in the object to be processed under the condition of multiphoton absorption to form the modified region 7. In addition, the 5 gastric collection points are the locations where the laser light L collects light. Further, the surface 10 of the object 1 is a laser light incident surface on which laser light is incident, and this surface is a flat and smooth surface which is prevented from being scattered by the laser light L. The laser light L is relatively moved along the line to cut 5 (i.e., in the direction of the arrow A) to move the light collecting point p along the line to cut 5 . As a result, the modified region 7 is formed only inside the object 1 along the line to cut 1 as shown in Figs. 3 to 5, whereby the region 7 is modified to form the cut-and-start region 8. In the laser processing method according to the present embodiment, the processed object 1 does not absorb the laser light L· and generates heat, and the modified region 7 is formed. On the other hand, the laser light L is transmitted through the object 1 to cause multiphoton absorption inside the object 1 to form a modified region. Therefore, the laser light L is hardly absorbed on the surface 10 of the object 1 to be processed, and the surface 10 of the object 1 is not melted. When the starting point of the object to be cut 1 has a starting point at the point to be cut, the object 1 is split from the starting point. Therefore, as shown in Fig. 6, the object to be processed can be cut with a small force. 1. Therefore, the object 1 can be cut without causing unnecessary splitting on the surface 10 of the object 1 to be processed. -12- 200914185 In addition, in the present embodiment, the modified region formed by multiphoton absorption has the following cases (1) to (3). (1) In the case where the modified region contains one or more cracked cracked regions: Align the light collecting points inside the substrate (for example, a piezoelectric material made of sapphire, glass, or LlTa〇3) The laser light is irradiated under the condition that the electric field intensity on the collecting point is lxl 〇 8 (W/cm 2 ) or more and the pulse width is 1 μ $ or less. This pulse width is sized to produce multiphoton absorption without impairing the surface of the substrate, but only on the inside of the substrate. Thereby, optical damage due to multiphoton absorption occurs inside the substrate, whereby a crack region is formed inside the substrate. The upper limit of the electric field strength is, for example, lxl 〇 12 (W/cm 2 ). A pulse width such as Ins to 200 ns is preferred. The inventors of the present invention obtained the relationship between the electric field strength and the size of the crack by an experiment. The experimental conditions are as follows. (A) Substrate: Pyrex (registered trademark) Glass (thickness 700μίη) (Β) Laser: Light source: Semiconductor laser excitation Nd ·· YAG Laser wavelength: 1064 nm Laser spot area: 3.14xl0_8cm2 Oscillation Form: Q switch pulse Cycle frequency: 1 00kHz Pulse width: 3 0 ns Output: Output <lmJ/pulse-13- 200914185 Laser light quality: ΤΕΜ00 Polarization characteristics: linear polarization (C) Light collection lens: Transmittance of laser light wavelength: 60% (D) Movement speed of the stage on which the substrate is placed: 100mm/sec In addition, the so-called laser light quality TEMoo means that the light collection is high and can cover the wavelength range of the laser light. Fig. 7 is a graph showing the results of the above experiment. The horizontal axis is the peak power density. Since the laser light is pulsed light, the electric field strength is expressed by the peak power density. The vertical axis 1 indicates the size of a crack portion (crack point) formed in the substrate by laser light of one pulse. The set crack point becomes the cracked area. The size of the crack point is the size of the largest length of the shape of the crack point. The data indicated by black circles in the curve is 1〇〇 times the magnification of the lens (C) and the number of openings (NA) is 0. Information on the situation of 80. In addition, the data represented by white circles in the curve is a magnification of 50 times the magnification of the lens (C), and the number of openings is 0. Information on the situation of 5 5 . It can be seen from the figure that a crack point starts to be generated inside the substrate from a peak power density of l 〇 W (W/cm 2 ), and the crack point increases as the peak power density increases. Next, a mechanism for cutting the object to be processed by the formation of the crack region in the laser processing according to the present embodiment will be described with reference to Figs. 8 to 11. As shown in Fig. 8, the laser beam L is irradiated to the object 1 by aligning the light collecting point P with the inside of the object 1 under the condition of multiphoton absorption, and the crack region 9 is formed inside along the line to cut. . The cracked region 9 is a cracked region containing one or more. The cracked region 9 is formed as a cut-off area from -14 to 200914185. As shown in FIG. 9, when an artificial force (for example, tensile stress) is applied to the object 1 to be processed, cracks are further generated starting from the crack region 9 (that is, starting from the cutting start region). Finally, as shown in Fig. 10, the crack reaches the upper and lower surfaces of the object to be processed, and as shown in Fig. 11, the object 1 is cut and cut. (2) In the case where the improvement region is a molten processing region, the inside of the substrate (for example, a semiconductor material of germanium) is aligned, and the electric field intensity at the light collecting point is lxl〇8 (W/cm2) and the pulse width. Irradiate the laser light for a condition of 1 or less. Thereby, the inside of the substrate is locally heated by multiphoton absorption. Due to the heating, a molten processed region is formed inside the substrate. The region to be melted is a region which is temporarily solidified and then solidified, and a region which is in a molten state, and a region which is resolidified from a molten state, and can also be referred to as a phase change region and a crystal structure change region. Further, the molten processed region refers to a region in which a certain structure is changed to another structure in a single crystal structure, an amorphous structure, or a polycrystalline structure. That is, for example, a region which changes from a single crystal structure to an amorphous structure, a region which changes from a single crystal structure to a polycrystalline structure, is structurally changed from a single crystal structure to a region containing an amorphous structure and a polycrystalline structure. In the case where the substrate is a single crystal structure, the molten processed region is, for example, an amorphous 构造 structure. The upper limit of the electric field strength is, for example, lxl012 (W/Cm2). The pulse width is preferably in the range of, for example, Ins to 200 ns. The inventors have experimentally confirmed that a molten processing region is formed inside the germanium wafer. The experimental conditions are as follows: (A) Substrate: germanium wafer (thickness 3 50 μιη, outer diameter 4 inches) -15- 200914185 (B) Laser: Light source: semiconductor laser excitation Nd: YAG laser wavelength: l〇 64nm laser spot area: 3. I4xl (T8cm2 oscillation mode: Q switching pulse Cycle frequency: 1 00kHz Pulse width: 30ns Output: 20m" Pulse Laser light quality: TEM〇〇 Polarization characteristics: Linear polarization (C) Light collection lens: Magnification: 5 0 times N. A. : 0. 55 Transmittance of the wavelength of the laser light: 60% (D) Movement speed of the mounting table on which the substrate is placed: 100 mm/sec Fig. 12 is a photograph showing a photograph of a section on a portion of a wafer which has been cut by laser processing under the above conditions. A molten processed region 13 is formed inside the germanium wafer 11. In addition, The thickness direction of the molten processing region 13 formed by the above conditions is about 100 μm. then, It is explained that the molten processed region 13 is formed by multiphoton absorption. Fig. 13 is a graph showing the relationship between the wavelength of the laser light and the transmittance inside the germanium substrate. but, The respective reflective components on the surface side and the back side of the ruthenium substrate are removed and only the internal transmittance is shown. The thickness t of the germanium substrate is shown to be 50 μm, ΙΟΟμιη, 200μιη, 500μιη, 上述μηι The above relationship. -16 - 200914185 For example, Nd : The YAG laser wavelength is 1 064 nm. When the thickness of the substrate is less than 500 μm, it can be seen from the figure that more than 80% of the laser light is transmitted through the inside of the substrate. The thickness of the germanium wafer 1 1 shown in Fig. 2 is 350 μηι, Therefore, the molten processed region 13 caused by the multiphoton absorption is formed on the portion 175 μm from the surface of the germanium wafer 11 when formed near the center of the germanium wafer 11. Transmittance in this case, If the reference thickness is 200μιη, the wafer is 90% or more. The amount of laser light absorbed by the inside of the silicon wafer 11 is small. Almost all transmission. This means that the inside of the germanium wafer 1 1 does not absorb the laser light and forms the molten processed region 13 inside the germanium wafer 1 1 (that is, the molten heat-treated region is not formed by the usual heating caused by the laser light) , Instead, a molten processing region is formed due to multiphoton absorption. In addition, The crucible wafer is split toward the cross-section direction starting from the cutting starting point region formed by the molten processing region. When this split reaches both sides of the wafer, it is cut off. According to the investigation of the inventors, The difference in physical properties between the molten processed region and other regions is generated, and strain is easily generated inside the germanium wafer. In addition, From the photograph shown in Fig. 12, it is understood that there is a head-like melting trace on the molten processing region 13. It is conceivable that the crack originating from the molten processing area is the melting trace. It can reach the lower two sides of Dazheng wafer with better precision. In addition, The molten treatment zone is only formed inside the sand crystal circle. From the cut surface after cutting, As shown in Figure 12, It is known that a molten processed region is formed only inside. After forming a cutting start region by the molten processed region inside the substrate, When cutting, it is not easy to split outside the line of the starting point. Therefore, it is easy to control the cut. -17- 200914185 (3) The case where the modified region is the index of refraction change region aligns the light collecting point inside the substrate (for example, glass), The laser light is irradiated at a condition that the electric field intensity on the collecting point is lxl 〇 8 (W/cm 2 ) or more and the pulse width is equal to or less than Ins. Make the pulse width very narrow, After generating multiphoton absorption inside the substrate, The energy generated by multiphoton absorption is not converted into thermal energy. And causing a change in the valence of ions inside the substrate, Permanent structural changes such as crystallization or polarization orientation, Further, a refractive index change region is formed. The upper limit of the electric field strength is, for example, lxl012 (W/cm2). Pulse widths such as Ins are preferred, But Ins is better. the above, The case of the modified regions (1) to (3) formed by multiphoton absorption is explained. However, when the cutting start point region is formed as described below in consideration of the wafer structure of the object to be processed and the detachment property thereof, the cutting starting point region is used as a starting point. The object to be processed can be cut with a smaller force and accuracy. In other words, In the case of a substrate made of a single crystal semiconductor having a diamond structure such as 矽, the cutting starting point region is formed along the (111) plane (first cleavage plane) and the (110) plane (second cleave plane). good. In addition, In the case of a substrate made of a III-V compound semiconductor of a zinc blende structure such as GaAs, it is preferable to form a cutting start region in the direction of the (1 1 0) plane. In addition, In the case of a substrate having a crystal structure of sapphire (a hexagonal crystal structure such as Ahoy et al., the (000 1 ) plane (C surface) is the main surface, It is preferable to form a cutting starting point region along the direction of the (1120) plane (A surface) or the (11 〇〇) surface (M surface). Further, if the substrate such as a disk-shaped wafer is cut, if -18-200914185 is along the direction required to form the above-described cutting start region (for example, along the direction of the (111) plane on the single crystal germanium substrate), Or in a direction orthogonal to the direction required to form the cutting start region, When an orientation flat is formed on a wafer, the orientation is flat based on the orientation. With this, The cutting start region in the direction required to form the cutting start region can be formed easily and correctly on the wafer. A laser processing apparatus used in the above-described laser processing method will be described with reference to Fig. 14. Fig. 14 is a schematic diagram of a laser processing apparatus 100. The laser processing apparatus 100 is provided with a laser light source 101 that generates laser light L, The laser light source control unit 102 that controls the laser light source 1 〇 1 in order to adjust the output and pulse of the laser light L, a dichroic mirror 103 having a function of reflecting the laser light L and configured to change the orientation of the optical axis of the laser light L by 90, a collecting lens 1〇5 for collecting the laser light L reflected by the dichroic mirror 103, The mounting table 107 of the processed object 1 irradiated with the laser light collected by the collecting lens 1 〇 5 is placed. The X-axis table 109 for moving the mounting table 1〇7 in the X-axis direction, The Y-axis stage 111 that moves the mounting table 1〇7 toward the Y-axis orthogonal to the X-axis, a Z-axis stage 113 for moving the mounting table 1〇7 in the Z-axis direction orthogonal to the X-axis and the Y-axis, And control these three stations 1〇9, 1 1 1, 1 1 3 mobile station control unit 1 1 5 . The movement of the light collecting point P in the X (Y) axis direction is performed by moving the object 1 in the axial direction of the x (Y) axis table 109 (111). The direction of the Ζ axis is perpendicular to the plane 10 of the object 1 to be processed, Therefore, the direction of the depth of focus of the laser light L incident on the object 1 is obtained. Yes, By -19- 200914185, the z-axis table 113 is moved in the Z-axis direction. The collection point p of the laser light L can be aligned inside the object 1 to be processed. The laser source 1 0 1 is the Nd that generates pulsed laser light: YAG laser. Can be used as a laser for laser light source 1 0 1 There is also Nd: YV04 laser, Nd : YLF laser and titanium sapphire laser. In this embodiment, Although the processing of the processing object 1 uses pulsed laser light, However, continuous wave laser light can be used as long as it can cause multiphoton absorption. The laser processing apparatus 100 further includes an observation light source 1 1 7 for generating visible light of the object 1 to be placed on the mounting table 107. And a beam splitter 119 for viewing light on the same optical axis as the dichroic mirror 103 and the light collecting lens 105. The dichroic mirror 103 is disposed between the beam splitter 119 and the collecting lens 1〇5. The beam splitter 119 has a half of the visible light reflected. One of the other functions of transmissive, And configured to change the orientation of the optical axis of the visible light by 90. About half of the visible light generated from the observation light source 1 17 is reflected by the beam splitter 119, The reflected visible light passes through the dichroic mirror 103 and the collecting lens 105, On the other hand, the surface 10 including the planned cutting line 5 of the object 1 is irradiated. The laser processing apparatus 100 further includes a beam splitter 119. And an imaging element 121 and an imaging lens 123 which are disposed on the same optical axis as the dichroic mirror 103 and the light collecting lens 105. As the imaging element 121, for example, a CCD camera is available. The irradiation table has a reflection light that cuts the visible light of the surface 10 such as the predetermined line 5, and penetrates the light collecting lens 105, Dichroic mirror 103, Beam splitter 119, After imaging on the imaging lens 123, it is photographed by the photographing element 121 as photographic material. -20- 200914185 The laser processing apparatus 100 further includes a photographic data processing unit 1 2 5 for inputting the photographic elements 121. And controlling the laser processing as a whole, the overall control unit 127, And monitor 129. Photographing data 1 25 is based on the photographic data calculation for aligning the focus of the observation light source i i 7 with the focus of the object 1 of the object 1 According to this focus information, The station control unit 11 5 moves the control Z ft , Thereby, the focus of the visible light is aligned on the surface of the object 1 and the photographic data processing unit 125 is used as an autofocus unit. The photographic data processing unit 1 2 5 is based on the photographic data. The calculation surface enlarges the image data such as images. This image data is then sent to the entire 1 2 7 ′ through the overall control department to perform various processing and sent to the monitor. An enlarged image or the like is displayed on the monitor 129. The overall control unit 1 2 7 inputs image data from the data processing unit 1 25 of the station control unit 1 1 5, and the like. According to these data, the laser light source control unit 102, Observe the light source! 7 and Taiwan Control Department Control the laser processing unit 100. Yes, The overall control unit operates as a computer unit. The laser processing method of the present invention using the above-described laser processing apparatus 100 will be described below. Fig. 15 is a view showing the wafer 1& which is shown in Fig. 15 in the laser processing method of the present embodiment. Fig. 17 is an enlarged view showing a section VI-VI VII of the wafer ia shown in Fig. 16. Referring to Figures 15 to 17, The wafer la is a flat plate that is about the disc's output. Connect & Taiwan 1 13 10. Yes. Another i 1 〇 body control 129. , And photo, Control 115, The 127 system is related to the view. . In addition and VII- shape. 参 -21 - 200914185 According to Figure 16, It is shown that a plurality of cutting planned lines 5 intersecting vertically and horizontally are set on the inner surface 21 of the wafer la. The line to cut 5 is a predetermined imaginary line for cutting the wafer 1 a into a plurality of wafer-like portions. This cutting planned line 5 can also be estimated along the cleavage plane of, for example, 1 a. In addition, The wafer la has a flat orientation (hereinafter referred to as "OF") 19. In this embodiment, The OF 1 9 is formed by forming a direction parallel to one of the cutting lines 5 intersecting vertically and horizontally as the longitudinal direction. The purpose of the OF19 setting is to easily determine the cutting direction when the wafer is cut along the line to cut 5 . In addition, Referring to Figure 17, The wafer 1a has a substrate 15 made of a semiconductor (Si). And a laminate portion 4 stacked on the surface 6 of the substrate 15. The laminated portion 4 has interlayer insulating layers 17a and 17b made of an insulating material (SiO 2 ). And a first wiring layer 19a and a second wiring layer 19b made of a metal (W). The interlayer insulating layer 17a is laminated on the surface 16 of the substrate 15, On the surface 6, a plurality of first wiring layers 19a are stacked on the element forming regions which are divided by each other. The first wiring layer 19a and the substrate 15 are electrically connected to each other by the plunger 20a penetrating the interlayer insulating layer 17a. The interlayer insulating layer 17b is laminated on the interlayer insulating layer 17a and the first wiring layer 19a. The region corresponding to the first interconnect layer 丨9a on the interlayer insulating layer 17b is laminated on the second interconnect layer 19b. The second interconnect layer 19b and the first interconnect layer 19a are electrically connected to each other through the plug 20b of the interlayer insulating layer 17b. On the interlayer insulating layer 1 7 b, The region of the gap between the second wiring layers 1 9 b is estimated as the planned cutting line 5. Here, the cut line 5 is cut, The surface of the interlayer insulating layer 17b (ie, Wafer 1 a surface 3) -22- 200914185 Flat and smooth. (First Embodiment) Figs. 18 and 19 are flowcharts for explaining a first embodiment of the laser processing method according to the present embodiment. In addition, Figs. 20 to 22 are sectional views for explaining the wafer 1a of the laser processing method according to the present embodiment. Referring to Figure 18, First, a protective tape 25 is attached to the surface 3 of the wafer la as a protective film for protecting the laminated portion 4 (S1, Figure 20A). The material of the protective tape 25 has a buffering effect of the protective laminate portion 4, Any material can be used without affecting the operational characteristics of the laminated portion 4. The present embodiment selects a material which can be removed by irradiation of ultraviolet rays in addition to absorbing an impact as a material of the protective tape 25. then, A cutting start point region 8 is formed along the line to cut 5 inside the substrate 15 of the wafer 1 a (S3, Figure 20B). Here, The wafer la shown in Fig. 20B is drawn such that the surface 3 is below the figure. In other words, The area corresponding to the line to cut 5 on the inner surface 21 of the wafer la is taken as the incident light surface of the laser light. Irradiating the laser light to the light collecting point p inside the substrate 15 Thereby, the molten processed region 13 is formed inside the substrate 15 as a modified region. This molten processed region 13 serves as a cutting start region 8 when the wafer is cut. Here, Fig. 19 is a view showing the use of the laser processing apparatus 100 shown in Fig. 14, A flow chart of a method of cutting the starting point region 8 is formed on the wafer la. In addition, In this embodiment, The wafer 1a is placed on the mounting table 107 of the laser processing apparatus 1 so that the inside 21 is opposed to the collecting lens 105-23-200914185. that is, The laser light L is incident on the inside of the wafer 1 a 2 1 . Referring to Figures 14 and 19, First of all, The light absorption characteristics of the substrate 15 are measured by a spectrophotometer or the like (not shown). According to the results of this measurement, The laser light source 101 which generates the laser light L having a wavelength which is transparent to the substrate 15 or has a low absorption wavelength is selected (S101). then, Considering the thickness of the substrate 15, Material and refractive index, etc. The amount of movement of the wafer la in the Z-axis direction is determined (S103). This is to align the spot P of the laser light L at a desired position inside the inner side 21 of the wafer la. The amount of movement in the Z-axis direction of the wafer laZ is based on the spot P of the laser light L located on the inside of the wafer 1a. This amount of movement is input to the overall control 127. The wafer 1a is placed on the mounting table 107 of the laser processing apparatus 100 such that the inner surface 21 of the wafer 1a faces the side of the collecting lens 010. At this time, The wafer surface 3 provided with the lamination portion 4 is provided with a protective tape 25, Therefore, even if the surface 3 side of the wafer 1a is placed on the mounting table 107, There will be no problems. also, The visible light is generated from the observation light source 1 1 7 to illuminate the inside 21 of the crystal la (S105). The inside 21 of the illuminated wafer la is photographed by the photographing element 1 2 1 . The photographic material photographed by the photographic element 1 21 is sent to the photographic material processing unit 125. According to this photographic material, The photographic data processing unit 125 calculates the focus data of the visible light of the observation light source 117 at the inside of the wafer la 21 (S107). This focus data is sent to the station control unit 1 15 . The stage control unit 1 1 5 moves the Z-axis stage 1 13 in the Z-axis direction based on the focus data (S1 09). With this, The focus of the visible light of the observation light source 117 is set at -21 - 200914185 inside the wafer la 21 . In addition, The photographic data processing unit 125 is based on photographic data. The calculation contains expanded image data of the inside 21 of the cut-off line 5. The enlarged image data is sent to the monitor 1 29 via the overall control unit 127. Thereby, the enlarged image near the cut-off line 5 is displayed on the monitor 129. The overall control unit 127 inputs the amount of movement data determined in advance in step S103. This movement amount data is then sent to the station control unit 1 15 . The station control unit 1 1 5 is based on the movement amount data, The wafer 1a is moved in the Z-axis direction by the Z-axis stage 1 1 3 so that the position of the light-collecting point P of the laser light L is located inside the predetermined distance from the inside 21 of the wafer la (Sill). then, Laser light L is generated from the laser source 01, The laser light L is irradiated onto the inside of the wafer 1 a 2 1 . The spot P of the laser light L is located inside the substrate 15 due to the tie. Therefore, the molten processed region 13 which is the modified region is formed only inside the substrate 15. also, The X-axis stage 10 9 and the Y-axis stage 1 1 1 are moved along the line to cut 5 to form a plurality of molten processed regions 13, Or continuously forming the molten processed region 13 along the line to cut 5, With this, A cutting start region 8 along the line to cut 5 is formed inside the substrate 15 (S 11 3) 〇 An extension tape 23 belonging to the ductile film is mounted on the inner surface 21 of the wafer la (S5, Figure 20C). The extension strip 23 is made of a material that can be stretched, for example, by stretching in the direction of extension. It is used to separate the wafer la into a wafer shape for subsequent operations. The extension belt 23 is in addition to being stretched in the direction of extension, It may also be, for example, a thing that can be stretched by heating. then, The wafer 1a is cut along the cutting starting point region 8 into a plurality of -25- 200914185 wafer-like portions 24 (S7 '21A). that is, The blade is opened from the extension tape 23 of the inside of the wafer la 21 against the cutting start point region 8, By applying a bending stress to the wafer 1 a, Further, the wafer la is cut (separated) by using the cutting start region 8 as a starting point. At this time, The cracks 18 of the surface 3 and the inner surface 21 are generated from the starting point region 8 from the inside of the wafer la. The substrate 15 is also cut, and the interlayer insulating layers 17a and 17b are also cut. As a measure to stress the wafer 1 a, Except for the edge 3 3 In addition, E.g, Splitting device, Roller device, etc. In addition, It is also possible to use energy that does not cause melting of the surface of the wafer 1 a surface 3 and the inner surface 2 1 , However, the laser light that can be absorbed by the wafer 1 a illuminates the wafer to generate thermal stress, and the crack is generated by cutting off the starting point region 8 as a starting point. In addition, It is also possible to resist with a knife edge or the like above the protective tape 25 mounted on the surface 3 of the crystal la. Further, bending stress is applied. then, The protective tape 25 mounted on the surface 3 of the wafer la is irradiated with ultraviolet V (S9, Figure 21B). The protective tape 25 is in a removable state by irradiating the protective tape 25 with ultraviolet rays V. then, Stripping the protective tape 25 from the surface 3 of the wafer la (S11, Figure 21C). Alternatively, the protective tape 25 may be peeled off before the wafer la (S7) is cut. then, The wafer la is separated into a wafer-like portion 24 (S 13, Figure 22), that is, The extension strip 23 is stretched to create a spacing 26 between the plurality of wafer-like portions 24. By virtue of this, it is easy to pick up the individual wafers of the plurality of wafer-like portions 24. As explained above, In the laser processing method of the present embodiment, the protective tape 2 5 ' is mounted on the surface 3 of the wafer 1 a to place the wafer 1 a on the mounting table 1 07 to the -26-200914185. therefore, It is preferable to irradiate the laser light L from the inside of the wafer 1 a to the inside of the substrate 1 5 . And by the so-called multiphoton absorption phenomenon to form a modified region, A cutting start region 8 along the line to cut 5 for cutting the wafer ia is formed inside the substrate 15. In addition, An extension tape 23 is mounted on the inner surface 21 of the wafer la, By stretching this extension belt 23, The majority of the wafer-like portion 24 of the cut wafer la can be easily separated. that is, According to the laser processing method related to the embodiment, The laser beam L can be irradiated without directly aligning the laminated portion 4 on the surface 3 of the wafer la to form the cutting start region 8, Therefore, damage to the laminated portion 4 by the laser light L can be prevented. In addition, By forming a cutting start point region 8 inside the substrate 15, The wafer la can be cut with a small and better precision by cutting off the starting point region 8 as a starting point. And the wafer can be easily separated. therefore, According to this laser processing method, Even if the wafer 1a has the laminated portion 4, the wafer 1a can be cut with high precision. In addition, According to the laser processing method related to the embodiment, The cutting width between the wafer-like portions 24 is particularly small compared to the conventional knife cutting method and the like. So reducing the cutting width, The spacing between the individual wafer-like portions 24 can be reduced, Further, more wafer-like portions 24 can be obtained. In addition, According to the constituent materials of the laminated portion 4 and the irradiation conditions of the laser light L, It is necessary to consider that the laser light L does not illuminate the element forming region of the laminated portion 4. Especially this method, In order to utilize the multiphoton absorption phenomenon, the laser light is sharply converged, therefore, Although it is a formation area where the laser light L does not illuminate the laminated portion 4, However, there are cases where it is not easy to irradiate the laser light from the surface 3. In addition -27- 200914185, Generally, a stacked semiconductor layer for an element is often present between the wafer element forming regions. or, The memory element and the integrated circuit component also form a TEG between the component regions (Test Element Group: Test component group) and other functional components. Such a situation, When the laser processing method according to the present invention is used, the laser light can be irradiated from the inside 21 of the laminated portion 4 without being irradiated. Thereby, the inside of the substrate 15 is preferably formed with the cutting start point region 8. In addition, The laser processing method according to this embodiment applies an external force by using a wafer 1 a such as a knife edge. The wafer 1a is broken into a plurality of wafer-like portions 24 starting from the cutting start region 8. With this, The wafer 1a can be easily cut by cutting the starting point region 8. In addition, The laser processing method according to this embodiment removes the protective tape 25 after the extension tape is mounted on the wafer 1a. With this, Can hold the wafer 1 a which forms the starting point region 1 The non-rose is divided into individual wafer portions 24. Fig. 23 is a sectional view for explaining a modification of the laser processing method according to the embodiment. This modification is inside the substrate 15, A plurality of molten processed regions 13 are formed in the thickness direction of the base 15. To melt the treated area 13, It suffices that the steps S 1 1 1 of the flowchart shown in Fig. 19 (moving the wafer in the Z-axis direction) and the step S 1 1 forming the modified region are performed alternately. Further, it is also possible to simultaneously perform the movement of the wafer 1a and the formation of the modified region in the Z-axis direction, thereby continuously forming the molten processed region 13 in the thickness direction of the substrate. As in this embodiment, By forming a molten processed region 13 The cutting start region 8 extending in the thickness direction of the plate 15 can be formed. Therefore, the leading side can cut the wafer 1 a with a smaller force of -28-200914185 on the plate shape of the 23-section cut. In addition, If the crack caused by the molten processed region 13 is grown in the thickness direction of the substrate 15, The wafer 1 a can be separated without external force. (Second Embodiment) Fig. 24 is a flowchart showing a second embodiment of the laser processing method executed in the embodiment. In addition, Figs. 25 to 27 are sectional views for explaining the wafer la of the present embodiment. This embodiment differs from the above-described first embodiment in that the substrate 15 is thinned and thinned. (2) Do not use the knife edge 33 to split, And (3) peeling off the protective tape 25 after separating the wafer la into a plurality of wafer-like portions 24. The third point. Referring to Figure 24, First, a protective tape 25 is mounted on the surface 3 of the wafer la (S21, Figure 25A). This operation is the same as step S1 on the first embodiment. Therefore, a detailed description thereof will be omitted. Then, honing the inside of the wafer la 21 (S23, Figure 25B). At this time, the thickness of the substrate 15 is honed to a thickness of, for example, 30 μm to 50 μm. In addition, the second operation can also honing the inside 21 so that the inside of the honed 21 is flat and smooth, and the laser light L is preferably incident from the inside 2 1 . then, Inside the substrate 15 of the wafer 1 a, A cutting start point region 8 is formed along the line to cut 5 (S25, Figure 25C). then, After honing the crystal la, the extension tape 23 is mounted inside the 21 (S27, Figure 26A). These operations are the same as steps S3 and S5 of the first embodiment described above, respectively. Therefore, detailed descriptions thereof will be omitted. Then 'extend the extension belt 23, Thereby, the wafer 1 a is cut into a plurality of wafer-shaped portions 24 by cutting off the starting point region 8 from the starting point of -29-200914185. At the same time, the individual wafer-like portions 24 are separated from each other (S29, Figure 26B). At this time, Since the substrate 15 has been sufficiently honed and thinned in the aforementioned step S23, Therefore, only the tensile stress generated by the extension of the extension belt 23 is obtained. The wafer 1 a is cut starting from the cutting start region 8 as a starting point. also, Extending the extension strip 23 so that A gap 26 is drawn between the majority of the wafer-like portions 24. then, The protective tape 25 is irradiated with ultraviolet rays (S31, Figure 26C), The protective tape 25 is peeled off from the surface 3 of the wafer la (S33, Figure 27). These operations are the same as steps S 9 and S 1 1 of the first embodiment described above, respectively. Therefore, detailed descriptions thereof will be omitted. In addition, It is also possible to peel off the protective tape 25 before the operation of stretching the wafer 23 to cut the wafer la (S29). The laser processing method according to this embodiment is the same as the first embodiment described above. The cutting start region 8 can be formed by directly irradiating the laminated portion 4 provided on the surface 3 of the wafer 1 a with the laser light L. Therefore, damage to the laminated portion 4 due to the laser light L can be prevented. In addition, By forming a cutting start region 8 inside the substrate 15, The wafer 1 a can be cut with a small and better precision starting from the cutting start region 8 It is easy to separate the wafer 1 a to be cut. Therefore, 'in accordance with the laser processing method, Even in the case where the laminated portion 4 is present on the wafer 1a, the wafer 1a can be cut with high precision. Further, the laser processing method according to the present embodiment is honing the inside 21 of the wafer la to thin the substrate 15 of the wafer 1a. With this, The wafer j a can be cut with a small force or without a special force starting from the cut-off starting point region 8. In addition, the thickness of the substrate 15 is thicker than that of the substrate 15. The wafer la can be cut with better precision. -30- 200914185 In addition, The laser processing method related to the embodiment, Extending the extension tape 23 mounted on the inner surface 21 of the wafer la, With this, The wafer 1 a is cut into a plurality of wafer-like portions 24 starting from the cutting start region 8 as a starting point. At the same time, the majority of the wafer-like portions 24 are separated from each other. The tensile stress is applied to the cutting start region 8 of the wafer 1a while the extension tape 23 is stretched. therefore, The wafer la can be preferably cut by starting the cutting start region 8 as a starting point. therefore, According to this embodiment, the operation of cutting the wafer 1a and the process of separating the wafers 1a into a plurality of wafer-like portions 24 can be simultaneously performed. This can reduce manufacturing operations. In addition, The laser processing method according to this embodiment irradiates the laser light L with the pupil surface 21 of the wafer 1a as a laser light incident surface. According to the experiment of the inventor, The modified region of the molten processed region 13 or the like tends to be formed on the side of the substrate 15 on the side of the incident light incident surface. therefore, The laser processing method, The cutting start point region 13 has a tendency to be formed on the side of the inner side 21 of the mounting extension band 23. In addition, The tensile stress applied when the stretch band 23 is stretched is larger in the vicinity of the inner surface 21 of the substrate 15 than in the vicinity of the surface 6. therefore, Inside the substrate 15, When the cutting starting point area 8 is biased toward the inner side 2 1 side, the extension of the extending belt 25 can be extended. The tensile stress acts more effectively on the cutting start point region 8. By the above, According to the laser processing method related to the embodiment, The tensile stress can be more effectively applied to the cutting starting point area, Further, the wafer 1a can be cut with a smaller force. In addition, the laser processing method related to the embodiment, The protective tape 25 is removed after the wafer 1a is separated into a plurality of wafer-like portions 24 by the extension of the extended tape 23. With this, After cutting the wafer 1 a until the majority of the wafers are taken out -31 - 200914185 It can protect a large number of wafer-like portions 24. (Third embodiment) Fig. 28 is a flow chart showing a third embodiment of the laser processing method executed in the present embodiment. This embodiment differs from the above-described first embodiment only in that it is split without using the knife edge 3 or the like. This modification will be described with reference to Figs. 20 to 22 shown in the first embodiment. Referring to Figure 28, First install the 25 on the surface 3 of the wafer la (S41, Figure 20A). then, The cutting planned line 5 is formed in the substrate 15 of the wafer la to form the cutting start region 8 (S43, 20B, then An extension tape 23 is mounted on the inner surface 21 of the wafer la (S45, Figure)). These operations are the same as the steps S5 of the first embodiment described above, respectively. Therefore, detailed descriptions thereof will be omitted. then, The protective tape 25 is irradiated with ultraviolet rays (S47, Figure 21B: The protective tape 25 is peeled off from the surface of the wafer la (S49, Figure 21C). The operation is performed in steps S 9 and S 1 1 of the first embodiment described above, respectively, and the detailed description thereof will be omitted. but, This modification does not apply the stress applied by 33. Therefore, there is no 18° as shown in Figures 21B and 21C. By stretching the extension belt 23, The wafer la is cut into a plurality of wafer-like portions 24 by cutting off the starting point region at 8 o'clock. At the same time, the sheet portions 24 are separated from each other (S51, Figure 22). At this time, This embodiment does not honing the substrate 15 like the second embodiment. Therefore, the tensile stress generated by the stretching of the extended band of the two embodiments is The same as the law of the first belt band along the map) ° 20C S 1~ , Put these same. The edge of the knife edge is cut into a crystal. The wafer 1a is cut off from the start point area -32 - 200914185 starting point. also, Keep the extension strip 2 3 stretched, A plurality of wafer-like portions 24 can be pulled apart by a space 26. The laser processing method related to the embodiment, For the same reason as the first embodiment described above, Even in the case where the wafer 1 a has the laminated portion 4, It is also possible to cut the wafer 1a with high precision. In addition, The laser processing method according to this embodiment is the same as that of the second embodiment described above. By stretching the extension belt 23, Starting from the cutting start point area 8, Cutting the wafer 1 a into a plurality of wafer-like portions 24, At the same time, the majority of the wafer-like portions are separated from each other. With this, The operation of cutting the wafer 1a and the operation of separating the plurality of wafer-like portions 24 can be simultaneously performed, In turn, manufacturing operations can be reduced. (Fourth Embodiment) Fig. 29 is a flowchart showing a fourth embodiment of the laser processing method executed in the embodiment. The difference between this embodiment and the first embodiment described above is only to honing the thinned substrate 15. This modification will be described with reference to Figs. 20 to 22 shown in the first embodiment and Fig. 25 shown in the second embodiment. Referring to Figure 29, First of all, A protective tape 25 is attached to the surface 3 of the wafer la (S61 'Fig. 20A). This operation is the same as that of the step S1 in the first embodiment, and detailed description thereof will be omitted. then, Honing wafer 1 & Inside 21 (S63, Figure 25B). This operation is the same as step S23 on the second embodiment. Therefore, detailed description thereof will be omitted. then, A cutting start region 8 is formed along the line to cut 5 in the inner portion of the substrate 15 (S65, 25C-33-200914185). This operation is the same as step S3 of the first embodiment. Therefore, a detailed description thereof will be omitted. then, Install the extension tape 23 inside the wafer la 21 (S67, Figure 20C), By applying an external force to the wafer 1a, The wafer 1a is cut into a plurality of wafer-like portions 24 along the cutting start region 8 (S69, Figure 21A), then, UV protection of the protective tape 2 5 (S 7 1, 2 1 B)), Stripping the protective tape 25 from the surface of the wafer la 3 (S73, Figure 21C), With the extension of the extension belt 23, Separating the individual wafer-like portions 24 of the wafer 1 a from each other (S 75, Figure 22). These operations are the same as steps S 5 to S 1 3 of the first embodiment described above, respectively. Therefore, detailed descriptions thereof will be omitted. but, This embodiment hones the inside of the wafer 1 a 2 1 at step S 63 Therefore, the thickness of the substrate 15 is lower than that of the 20C chart. Figures 21A to 21C, The substrate 15 shown in Fig. 22 is thin. In addition, It is also possible to peel off the protective tape 25 before cutting the wafer la (S69). The laser processing method according to this embodiment is the same as the above-described first embodiment, Even in the case where the wafer 1 a has the laminated portion 4, It is also possible to cut the wafer la with high precision. In addition, The laser processing method according to this embodiment is the same as that of the second embodiment. Honing the inner 2 1 of the wafer 1 a to thin the substrate 1 5 of the wafer 1 a. With this, It is possible to use a smaller knife or to start the cutting start point area 8 without special effort. Cutting the wafer 1 a with high precision. In addition, The laser processing method according to this embodiment is the same as that of the first embodiment. By applying an external force, the starting point area 8 is cut off as a starting point. The wafer 1 a is cut into a plurality of wafer-like portions 24 . With this, Starting from the starting point area -34- 200914185 8 The wafer ia is easily cut. The above has described the embodiments and examples of the present invention in detail. However, the present invention is not limited to the above embodiments and examples. For example, in the above embodiments and examples, a semiconductor substrate is used as the substrate. However, the present invention is not limited to a semiconductor substrate, It can also be preferably applied to a substrate having conductivity. And the case of an insulating substrate. (Industrial Applicability) As described above, the laser processing method according to the present invention, By installing a protective film on the surface of the processed object, Since the object to be processed can be placed on the mounting table in the inside, it is possible to irradiate the inside of the substrate with laser light from the inside of the object. In addition, the modified area formed by the phenomenon of so-called multiphoton absorption is along the desired cutting line. A cutting start region required for cutting the object to be processed is formed inside the substrate, Further, the object to be processed can be cut with the cutting starting point region as a starting point. also, A ductile film is attached to the inside of the object to be processed by stretching the ductile film. Most parts of the object to be cut can be easily separated. that is, According to the laser processing method, It is possible to directly irradiate the laminated portion on the surface of the object to be irradiated with the laser light to form the cutting starting point region ′, and to use the cutting starting point region as a starting point with a small force. The object to be processed is preferably cut with precision, The object to be cut can be easily separated. therefore, According to this laser processing method, Even if the object to be processed has various laminated structures, The workpiece can also be cut with high precision. -35- 200914185 BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view showing an object to be processed in laser processing performed by the laser processing method according to the present embodiment. Fig. 2 is a sectional view taken along line 11 of the object to be processed shown in Fig. 1. Fig. 3 is a plan view showing the object to be processed after the laser processing performed by the laser processing method according to the embodiment. Fig. 4 is a sectional view taken along line IV-IV of the object to be processed shown in Fig. 3. Fig. 5 is a cross-sectional view taken along line V - V of the object shown in Fig. 3 . Fig. 6 is a plan view showing the object to be processed after the cutting by the laser processing method according to the embodiment. Fig. 7 is a graph showing the relationship between the electric field intensity and the crack point size in the laser processing method according to the present embodiment. Fig. 8 is a cross-sectional view showing the object to be processed in the first operation of the laser processing method according to the embodiment. Fig. 9 is a cross-sectional view showing the object to be processed in the second operation of the laser processing method according to the embodiment. Fig. 10 is a cross-sectional view showing the object to be processed in the third operation of the laser processing method according to the embodiment. Fig. 1 is a cross-sectional view showing an object to be processed in the fourth operation of the laser processing method according to the embodiment. Fig. 1 is a view showing a photograph of a section of one of the wafers of the cut-off wafer by the laser processing method according to the embodiment. Fig. 1 is a graph showing the relationship between the wavelength of the laser light and the transmittance of the inside of the ruthenium substrate in the laser processing method according to the present embodiment. Fig. 14 is a schematic diagram of a laser processing apparatus according to the present embodiment. Fig. 15 is a perspective view showing a wafer used in the laser processing method according to the embodiment. Figure 16 is a plan view of the wafer in Figure 15. Fig. 17 is an enlarged view showing a VI-VI section and a VII-VII section of the wafer shown in Fig. 16. Fig. 18 is a flowchart for explaining the laser processing method and the first embodiment of the present embodiment. Fig. 19 is a flow chart showing a method of forming a cutting start region in a wafer using the laser processing apparatus shown in Fig. 14. 20A to 20C are sectional views for explaining a wafer of the laser processing method according to the first embodiment. 21A to 21C are sectional views for explaining the wafer of the laser processing method according to the first embodiment. Figure 22 is a cross-sectional view showing a wafer for explaining the laser processing method according to the first embodiment. Figure 23 is a cross-sectional view for explaining a modification of the laser processing method according to the first embodiment. Fig. 24 is a flow chart for explaining a second embodiment of the laser processing method according to the embodiment. -37- 200914185 The 25A to 25C drawings are sectional views for explaining the wafer of the laser processing method according to the second embodiment. Figs. 26A to 26C are sectional views for explaining the wafer of the laser processing method according to the second embodiment. Figure 27 is a cross-sectional view showing a wafer for explaining the laser processing method according to the second embodiment. Fig. 28 is a flow chart for explaining a third embodiment of the laser processing method according to the embodiment. Fig. 29 is a flow chart for explaining a fourth embodiment of the laser processing method according to the embodiment. [Main component symbol description] 1 : Processing object 1 a : Wafer 3: Surface 4 : Lamination section 5 : Cut off the booking line 6 : Wafer surface 7 : Modified area 8 : Cut off the starting point area 9 : Cracked area 1 〇 : Face 1 of the object 1 3 : Melted processing area 1 5 : Substrate -38- 200914185 1 7 a : Interlayer insulation layer 1 9 a : The first wiring layer 2 0 a : Plunger 21 : Inside the wafer 23 __Extension tape 25 : Protective tape 1 〇 〇 : Laser processing equipment 1 〇 1 __Laser light source 102 ‘·Laser light source control unit 1 0 3 : Dichroic mirror 1 〇 5 : Light collecting lens 107 : Loading table 1 0 9 : X-axis table 1 1 1 : Y-axis table 1 13 : Z-axis table 1 1 5 : Station control unit 119: Beam splitter 1 2 1 : Photography component 1 2 3 : Imaging lens 125 : Photographic Processing Department 127 : Overall control unit 1 2 9 : Monitor