1310582 九、發明說明： 【發明所屬之技術領域】 本發明係有關於一種晶圓之雷射標示方法，特別係有 關於一種在薄化晶圓之背面之雷射標示方法。 【先前技術】1310582 IX. Description of the Invention: [Technical Field] The present invention relates to a laser marking method for a wafer, and more particularly to a laser marking method on the back side of a thinned wafer. [Prior Art]
積體電路產品係經電路集積化且大量生產於—晶圓 (wafer)，再切割成個別晶粒（die，或稱晶片），以供後續封 裝或組裝作業。由於積體電路種類繁多，故通常會在晶粒 之背面作出雷射標記（laser mark)，例如各式字母或數字之 字元’以利易於辨識晶片型態或批號。相關技術可參見於 中華民國專利公告第395041號「雷射標記之晶片—曰 曰曰 粒之正面（即主動面）形成有複數個電晶體元件，晶粒之背 面係形成有雷射標記，作為晶粒身分辨識作用。 目刖雷射標記之製作係在 前，可以大量且快速地形成一晶圓内所有晶粒之雷射標 記’但對於薄化之晶圓則有實施及製作上的困難。請參閱 第1圖，一晶圓10係包含有複數個晶粒，該些晶粒係具 有個別之晶粒背面n，位於該晶圓1〇之同—表面。在每 S日粒背面11上係應形成有一雷射標記2〇。請參閱第2 圖’在對該晶圓1 〇進行雷私护+吐 疋仃；射；^不時，必須是完整且有相 當厚度之晶圓10方能皮a 干放置並固疋於一雷射標示設備 之一套件30(kit)上，該套件3〇孫且古 去1干係具有一開口 31，以顯露 出該些晶粒背面11，如此可 此了利用一雷射光源4〇對該晶圓 10溶燒出上述之雷射禅印 ' 而‘該晶圓ίο要求薄化 1310582 而晶背研磨時，一旦厚度太薄，放置於該套件3〇上之晶 圓ίο會產生翹曲，導致雷射標示時，會有距焦不準位^ 偏移與標記不清晰之問題。已知晶圓尺寸越大，厚度則必 須越厚，以防止雷射標示時晶圓翹曲，例如8吋晶圓之厚 度須在6密耳（mil)以上（1 mil = 25.4 μιη)，12吋晶圓之厚 度須在12密耳（mil)以上，否則無法製作精確且正確之雷 射標記20。 【發明内容】 本發明之主要目的在於提供一種晶圓之雷射標示方 法，能在一薄化（晶圓厚度係介於密耳）之晶圓上形成 雷射標記，其係利用一透光載板作為一晶圓之放置，並令 該晶圓之一背面平貼接觸該透光載板，當雷射標示時，^ 射光係通過該透光載板而照射於該晶圓之該背面，以形成 雷射標記，解決習知薄化之晶圓無法雷射標示之問題。 本發明之次一目的在於提供一種晶圓之雷射標示方 法，一可供在雷射標示時放置晶圓之透光載板係具有一吸 氣槽或是複數個吸氣孔，用以吸附該晶圓之一周緣區，在 不干擾雷射光路徑之操作下使晶圓平貼，確保薄化之晶圓 在雷射標示時不會翹曲、偏移與震動，以形成精準且正確 之雷射標記。 本發月之再目的在於提供一種晶圓之雷射標示方 法以及該晶圓，所提供之—晶圓由其主動面至背面之厚度 係介於1~12密耳（mil)，且在該晶圓之背面係形成至少一 雷射標記，以提供一種具有雷射標記之薄化晶圓。 1310582 依據本發明之一種晶圓之雷射標示方法，提供—晶 圓，該晶圓係具有一主動面以及一背面，並且該晶圓由該 主動面至該背面之厚度係介於1^2密耳（mil);之後放 置該晶圓於一透光載板之上，其中該晶圓之該背面係平貼 接觸該透光載板；再進行一雷射標示之步驟，雷射光係通 過該透光載板而照射於該晶圓，以在該晶圓之該背面形成 至少一雷射標記。 【實施方式】 本發明之晶圓之雷射標示方法係以一具體實施例係 說明如下。 凊參閱第3圖，首先提供一晶圓11 〇，該晶圓J i 〇係 包含有複數個晶粒並具有一主動面111以及一背面112。 在該主動面111上對應每一晶粒區域係形成有各式積體電 路、銲墊與保護層（圖未繪出）。請再參閱第3及5圖，該 晶圓11〇之該背面112係包含有複數個晶粒背面ιΐ3以及 • 一無晶粒之周緣區114。並且可藉由一晶背研磨步驟，控 制晶圓厚度，令該晶圓110由該主動面m至該背面工二 之厚度係介於1〜12密耳（mil)，達到晶圓薄化，以供高密 度晶片堆疊、薄型封裝或是其它用途。在更具體的界定 上，當該晶圓U0係為12吋晶圓，則該晶圓11〇之厚度 •係介於1〜12密耳（mil);該晶圓11〇係為8叶晶圓時^ 該晶圓110之厚度係介於1~6密耳⑴。 之後，請參閱第4圖，將該晶圓11〇放置於一透光載 板12〇之上，並令該晶圓110之該背面112係平貼接觸該 1310582 透光載板120。在本實施例中，該透光載板i2〇係為—種 不吸收雷射光能量之玻璃並具有一平坦面，以供在雷射標 示過程中承載該晶圓110並可供雷射光穿透。此外，較佳 地，5亥透光載板120係具有一吸氣槽121，用以吸附該晶 圓110之該背面112，使該晶圓110平貼固定於該透光載 板120，可以避免在雷射標示時該晶圓11〇之魅曲、偏移 與震動。在不同實施例中，亦能以複數個吸氣孔替代該吸 氣槽121。請再參閱第4及5圖，該吸氣槽121係形成在 s亥透光載板120之適當位置，而能吸附該背面112之該周 緣區114，使該晶圓110更加平貼且不滑移，亦不干擾形 成雷射標記之雷射光路徑。 之後，請參閱第6圖，進行一雷射標示之步驟，上述 承載該晶圓110之透光載板12〇係固定於一雷射標示設備 之套件130，且該套件130係具有一可供雷射光作業之開 口 131，由一雷射光源14〇發出之雷射光係通過該透光载 ❿板120而照射於該晶圓1 ίο。該雷射光係為波長介於2〇〇 至850nm間之低能量雷射光，例如該雷射光係為波長約在 532nm之綠光雷射（green laser ) ’能適度熔燒在該晶粒背 面H3,故可在該晶圓110之該背面12()形成複數個日雷射 標記150，其中所形成之該些雷射標記15〇係對應形成於 該些晶粒背面113，以利切割後之晶粒辨識。因此，利用 上述之方法，能解決習知薄化之晶圓無法水平固定地進用 雷射標不之問題。 "" 本發明之保護範圍當視後附之申請專利範圍所界定 1310582 者為準，任何熟知此項技藝者， 範圍内所作之任何變化與1多改 圍。 【圖式簡單說明】 第1圖··習知晶圓之背面示意圖。 第2圖：習知晶圓在雷射標示時之截面示意圖。Integrated circuit products are integrated by circuitry and mass produced in wafers and then diced into individual dies (die, or wafer) for subsequent packaging or assembly operations. Due to the wide variety of integrated circuits, laser marks, such as various alphanumeric characters, are typically placed on the back side of the die to facilitate easy identification of the wafer type or lot number. Related art can be found in the Republic of China Patent No. 395041 "Laser-marked wafer - the front side of the enamel particle (ie, the active surface) is formed with a plurality of transistor elements, and the back side of the crystal grain is formed with a laser mark as Identification of grain identity. The goal of laser marking is to create laser markings for all grains in a wafer in large quantities and quickly. However, it is difficult to implement and manufacture thinned wafers. Referring to FIG. 1, a wafer 10 includes a plurality of crystal grains having individual die back surfaces n located on the same surface of the wafer. The upper system shall be formed with a laser marking 2〇. Please refer to Figure 2 for the protection of the wafer 1 + + 疋仃 疋仃 射 射 射 射 射 射 ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ The skin can be placed dry and fixed on a kit of one of the laser marking devices, the kit 3 and the ancient one has an opening 31 to reveal the back side of the die 11 The laser light can be used to dissolve the wafer 10 by using a laser light source 4 Zen printing 'and' the wafer ίο requires thinning 1310582. When the crystal back is ground, once the thickness is too thin, the wafer 放置 placed on the 3 会 of the kit will warp, resulting in a focus when the laser is marked. The problem of misalignment and unclear marking is not known. The larger the wafer size, the thicker the thickness must be to prevent wafer warpage during laser marking. For example, the thickness of 8 吋 wafer must be 6 mils. Above (mil) (1 mil = 25.4 μιη), the thickness of the 12-inch wafer must be above 12 mils, otherwise accurate and correct laser markings 20 cannot be made. [Invention] The main purpose of the present invention is Providing a laser marking method for forming a laser marking on a thinned wafer having a wafer thickness of mil, which uses a transparent carrier as a wafer, and The back surface of the wafer is placed in contact with the transparent carrier plate. When the laser is marked, the light is transmitted through the transparent carrier to the back surface of the wafer to form a laser mark. The thinned wafer cannot be marked by laser. The second purpose of the present invention is to mention A laser marking method for a wafer, wherein a light-transmissive carrier plate for placing a wafer during laser marking has an air suction slot or a plurality of air suction holes for adsorbing a peripheral region of the wafer. The wafer is flattened without disturbing the laser light path, ensuring that the thinned wafer does not warp, deflect and vibrate during laser marking to form accurate and correct laser markings. A further object is to provide a laser marking method for a wafer and the wafer provided, wherein the thickness of the wafer from the active surface to the back side is between 1 and 12 mils and is on the back side of the wafer. Forming at least one laser mark to provide a thinned wafer having a laser mark. 1310582 A laser marking method for a wafer according to the present invention provides a wafer having an active surface and a a back surface, and the thickness of the wafer from the active surface to the back surface is between 1 and 2 mils; the wafer is then placed on a light-transmissive carrier, wherein the back surface of the wafer is flat Attaching to the light-transmissive carrier; performing a laser marking step, the laser light system Through the transparent carrier plate is irradiated on the wafer to form at least a back surface of the laser marking of the wafer. [Embodiment] The laser marking method of the wafer of the present invention is described below with reference to a specific embodiment. Referring to Figure 3, a wafer 11 is first provided. The wafer J i includes a plurality of crystal grains and has an active surface 111 and a back surface 112. Various integrated circuits, pads, and protective layers (not shown) are formed on the active surface 111 for each of the grain regions. Referring again to Figures 3 and 5, the backside 112 of the wafer 11 includes a plurality of die backs ι 3 and a die free perimeter region 114. And the wafer thickness can be controlled by a crystal back grinding step, so that the thickness of the wafer 110 from the active surface m to the back surface is between 1 and 12 mils, thereby achieving wafer thinning. For high-density wafer stacking, thin packaging or other applications. In a more specific definition, when the wafer U0 is a 12-inch wafer, the thickness of the wafer 11 is between 1 and 12 mils; the wafer 11 is 8-leaf crystal. Round time ^ The thickness of the wafer 110 is between 1 and 6 mils (1). Then, referring to FIG. 4, the wafer 11 is placed on a transparent carrier 12A, and the back surface 112 of the wafer 110 is in flat contact with the 1310582 transparent carrier 120. In this embodiment, the transparent carrier plate i2 is a glass that does not absorb laser light energy and has a flat surface for carrying the wafer 110 during laser marking and is available for laser light to penetrate. . In addition, the light-transmissive carrier 120 has a suction slot 121 for adsorbing the back surface 112 of the wafer 110, so that the wafer 110 is flatly fixed to the transparent carrier 120. Avoid the fascination, deflection and vibration of the wafer during laser marking. In various embodiments, the suction slots 121 can also be replaced with a plurality of suction holes. Referring to FIGS. 4 and 5 again, the air suction slot 121 is formed at a suitable position on the transparent transmission board 120, and can absorb the peripheral area 114 of the back surface 112 to make the wafer 110 more flat and not Slip, and does not interfere with the laser light path that forms the laser mark. Thereafter, referring to FIG. 6, a laser marking step is performed. The transparent carrier 12 carrying the wafer 110 is fixed to a kit 130 of a laser marking device, and the kit 130 has one In the opening 131 of the laser light operation, the laser light emitted from a laser light source 14 is irradiated onto the wafer 1 through the light-transmitting carrier 120. The laser light is low-energy laser light having a wavelength between 2 〇〇 and 850 nm, for example, the laser light is a green laser having a wavelength of about 532 nm, and can be appropriately melted on the back surface of the die H3. Therefore, a plurality of day laser markings 150 can be formed on the back surface 12 of the wafer 110, wherein the laser markings 15 are formed corresponding to the back surface 113 of the die to facilitate cutting. Grain identification. Therefore, by the above method, it is possible to solve the problem that the conventional thinned wafer cannot be used in a horizontally fixed manner. "" The scope of protection of the present invention is subject to the definition of 1310582, which is defined by the scope of the appended claims, and any changes made within the scope of any one skilled in the art will be modified. [Simplified description of the drawings] Fig. 1 is a schematic view of the back side of a conventional wafer. Figure 2: A schematic cross-sectional view of a conventional wafer at the time of laser marking.
在不脫離本發明之精神和 均屬於本發明之保護範Without departing from the spirit of the invention and belonging to the protection of the invention
圖依據本發明之一具體實施例，所提供之晶圓之 面示意圖。 第4圖.依據本發明之一具體實施例，該晶圓在放置在一 透光载板後之截面示意圖。 第5圖.依據本發明之一具體實施例，該晶圓在放置在一 透光載板後之背面示意圖。 第6圖：依據本發明之一具體實施例，該晶圓在雷射標示 時之截面示意圖。 【主要元件符號說明】 10 晶圓 30 套件 110 晶圓 113 晶粒背面 120 透光載板 130 套件 140 雷射光源BRIEF DESCRIPTION OF THE DRAWINGS The Figure is a schematic illustration of a wafer surface provided in accordance with an embodiment of the present invention. Figure 4 is a cross-sectional view of the wafer after it has been placed on a light transmissive carrier in accordance with an embodiment of the present invention. Figure 5 is a schematic illustration of the back side of the wafer after being placed on a light transmissive carrier in accordance with an embodiment of the present invention. Figure 6 is a cross-sectional view of the wafer at the time of laser marking in accordance with an embodiment of the present invention. [Main component symbol description] 10 Wafer 30 Kit 110 Wafer 113 Die back 120 Translucent carrier 130 Kit 140 Laser source
11 晶粒背面 31 開口 111主動面 114周緣區 121吸氣槽 131 開口 150雷射標記 20 雷射標記 40 雷射光源 112背面11 Die back 31 Opening 111 Active surface 114 Peripheral area 121 Suction slot 131 Opening 150 Laser marking 20 Laser marking 40 Laser light source 112 Back