JP2020189493A - Method for manufacturing internal processing layer formation single crystal substrate, and method for manufacturing single crystal substrate - Google Patents
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Abstract
Description
本発明は、単結晶基板の表面から単結晶基板内部にレーザ光を集光することで、単結晶基板内部に加工層を形成した内部加工層形成単結晶基板の製造方法、および、単結晶基板の製造方法に関する。 The present invention provides a method for producing an internally processed layer-forming single crystal substrate in which a processed layer is formed inside the single crystal substrate by condensing laser light from the surface of the single crystal substrate into the inside of the single crystal substrate, and a single crystal substrate. Regarding the manufacturing method of.
従来、単結晶のシリコン（Ｓｉ）ウエハに代表される半導体ウエハを製造する場合には、石英るつぼ内に溶融されたシリコン融液から凝固した円柱形のインゴットを適切な長さのブロックに切断して、その周縁部を目標の直径になるよう研削し、その後、ブロック化されたインゴットをワイヤソーによりウエハ形にスライスして半導体ウエハを製造するようにしている。 Conventionally, when manufacturing a semiconductor wafer typified by a single crystal silicon (Si) wafer, a cylindrical ingot solidified from a silicon melt melted in a quartz crucible is cut into blocks of an appropriate length. Then, the peripheral portion thereof is ground to a target diameter, and then the blocked ingot is sliced into a wafer shape by a wire saw to manufacture a semiconductor wafer.
このようにして製造された半導体ウエハは、前工程で回路パターンの形成等、各種の処理が順次施されて後工程に供され、この後工程で裏面がバックグラインド処理されて薄片化が図られることにより、厚さが約７５０μｍから１００μｍ以下、例えば７５μｍや５０μｍ程度に調整される。 The semiconductor wafer manufactured in this way is subjected to various processes such as forming a circuit pattern in the pre-process and is subjected to the post-process, and the back surface is back-grinded in the post-process to be thinned. As a result, the thickness is adjusted from about 750 μm to 100 μm or less, for example, about 75 μm or 50 μm.
従来における半導体ウエハは、以上のように製造され、インゴットがワイヤソーにより切断され、しかも、切断の際にワイヤソーの太さ以上の切り代が必要となるので、厚さ０．１ｍｍ以下の薄い半導体ウエハを製造することが非常に困難であり、製品率も向上しないという問題がある。 Conventional semiconductor wafers are manufactured as described above, and the ingot is cut by a wire saw, and a cutting allowance larger than the thickness of the wire saw is required for cutting. Therefore, a thin semiconductor wafer having a thickness of 0.1 mm or less is required. There is a problem that it is very difficult to manufacture and the product rate does not improve.
一方、集光レンズでレーザ光の集光点をインゴット（ウエハ）の内部に合わせ、そのレーザ光でインゴットを相対的に走査することにより、インゴットの内部に多光子吸収による面状の改質層（加工層）を形成し、この改質層を剥離面としてインゴットの一部を基板として剥離することが開示されている（例えば、特許文献１参照）。 On the other hand, by aligning the condensing point of the laser light with the condensing lens to the inside of the ingot (wafer) and scanning the ingot relatively with the laser light, a planar modified layer by multiphoton absorption is formed inside the ingot. It is disclosed that a (processed layer) is formed and a part of the ingot is peeled off as a substrate by using this modified layer as a peeling surface (see, for example, Patent Document 1).
なお、この明細書中においては、別記する場合を除いてウエハのことを適宜に基板と称する。 In this specification, the wafer is appropriately referred to as a substrate unless otherwise specified.
ところで、単結晶基板の寸法が使用予定の寸法よりも大きい場合、この単結晶基板を小さい寸法にして再利用することができれば効率的である。 By the way, when the size of the single crystal substrate is larger than the size to be used, it is efficient if the single crystal substrate can be made smaller and reused.
本発明は、上記課題に鑑み、単結晶基板からそれよりも小さい寸法の単結晶基板を得ることを可能にする内部加工層形成単結晶基板の製造方法、および、単結晶基板の製造方法を提供することを課題とする。 In view of the above problems, the present invention provides a method for producing an internally processed layer-forming single crystal substrate and a method for producing a single crystal substrate, which makes it possible to obtain a single crystal substrate having a smaller size from the single crystal substrate. The task is to do.
上記課題を解決するための本発明の一態様によれば、レーザ光を集光するレーザ集光手段を、加工対象単結晶基板の被照射面上に非接触に配置する第１工程と、前記レーザ集光手段により前記加工対象単結晶基板内部にレーザ光を集光しつつ、レーザ光の集光位置を前記加工対象単結晶基板のくり抜き対象部の周囲方向に変化させることで、破断強度が低下した加工層を前記くり抜き対象部の周囲に形成する第２工程と、を備えた内部加工層形成単結晶基板の製造方法が提供される。 According to one aspect of the present invention for solving the above problems, the first step of arranging the laser condensing means for condensing the laser light on the irradiated surface of the single crystal substrate to be processed in a non-contact manner, and the above. While the laser light is focused inside the single crystal substrate to be processed by the laser condensing means, the breaking strength is increased by changing the condensing position of the laser light toward the periphery of the hollowed out target portion of the single crystal substrate to be processed. Provided is a method for producing an internal processed layer-forming single crystal substrate comprising a second step of forming a lowered processed layer around the hollowed-out target portion.
本発明の別の態様によれば、レーザ光を集光するレーザ集光手段を、加工対象単結晶基板の被照射面上に非接触に配置する第１工程と、前記レーザ集光手段により前記加工対象単結晶基板内部にレーザ光を集光しつつ、レーザ光の集光位置を前記加工対象単結晶基板のくり抜き対象部の周囲方向に変化させることで、破断強度が低下した加工層を前記くり抜き対象部の周囲に形成する第２工程と、前記加工層から破断させて前記くり抜き対象部をくり抜く第３工程と、を備えたことを特徴とする単結晶基板の製造方法が提供される。 According to another aspect of the present invention, the first step of arranging the laser condensing means for condensing the laser light on the irradiated surface of the single crystal substrate to be processed in a non-contact manner, and the laser condensing means. The processed layer having reduced breaking strength is obtained by changing the condensing position of the laser light toward the periphery of the hollowed-out target portion of the single crystal substrate to be processed while condensing the laser light inside the single crystal substrate to be processed. Provided is a method for manufacturing a single crystal substrate, which comprises a second step of forming around the hollowed-out target portion and a third step of breaking the processed layer to hollow out the hollowed-out target portion.
本発明によれば、単結晶基板からそれよりも小さい寸法の単結晶基板を得ることを可能にする内部加工層形成単結晶基板の製造方法、および、単結晶基板の製造方法を提供することができる。 According to the present invention, it is possible to provide a method for producing an internally processed layer-forming single crystal substrate, and a method for producing a single crystal substrate, which makes it possible to obtain a single crystal substrate having a smaller size from the single crystal substrate. it can.
以下、添付図面を参照して、本発明の実施の形態について説明する。以下の説明では、すでに説明したものと同一または類似の構成要素には同一または類似の符号を付し、その詳細な説明を適宜省略している。また、以下に示す実施の形態は、この発明の技術的思想を具体化するための例示であって、この発明の実施の形態は、構成部品の材質、形状、構造、配置等を下記のものに特定するものではない。この発明の実施の形態は、用紙を逸脱しない範囲内で種々変更して実施できる。 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, components that are the same as or similar to those already described are designated by the same or similar reference numerals, and detailed description thereof will be omitted as appropriate. Further, the embodiments shown below are examples for embodying the technical idea of the present invention, and the embodiments of the present invention describe the materials, shapes, structures, arrangements, etc. of the components as follows. It is not specific to. The embodiment of the present invention can be modified in various ways without departing from the paper.
図１は、本発明の一実施形態（以下、本実施形態という）で内部加工層形成単結晶基板を製造することを説明する模式的な側面図である。図２（ａ）から（ｃ）は、本実施形態で内部加工層形成単結晶基板を製造するプロセスを説明する模式定な側面図である。図３(ａ)および(ｂ)は、それぞれ、本実施形態で内部加工層が形成されていくことを示す模式的な側面断面図である。図４は、本実施形態に係る内部加工層形成単結晶基板から単結晶基板をくり抜くことを説明する模式的な斜視図である。図５は、本実施形態に係る内部加工層形成単結晶基板から単結晶基板をくり抜くことの変形例を説明する模式的な斜視図である。図６は、本実施形態に係る内部加工層形成単結晶基板から単結晶基板をくり抜くことの変形例を説明する模式的な斜視図である。図７は、本実施形態に係る内部加工層形成単結晶基板から単結晶基板をくり抜くことの変形例を説明する模式的な斜視図である。図８は、本実施形態に係る内部加工層形成単結晶基板の変形例で、複数の単結晶基板を得るための加工状態を示す模式的な平面図である。図９は、実験例の加工条件１で得られた内部加工層形成単結晶部材の断面を示す写真図である。図１０は、実験例の加工条件４で得られた内部加工層形成単結晶部材の断面を示す写真図である。 FIG. 1 is a schematic side view illustrating that an internally processed layer-forming single crystal substrate is manufactured according to an embodiment of the present invention (hereinafter referred to as the present embodiment). 2 (a) to 2 (c) are schematic side views illustrating a process of manufacturing an internally processed layer-forming single crystal substrate in the present embodiment. 3A and 3B are schematic side sectional views showing that an internal processed layer is formed in the present embodiment, respectively. FIG. 4 is a schematic perspective view illustrating that the single crystal substrate is hollowed out from the internally processed layer-forming single crystal substrate according to the present embodiment. FIG. 5 is a schematic perspective view illustrating a modified example of hollowing out the single crystal substrate from the internally processed layer-forming single crystal substrate according to the present embodiment. FIG. 6 is a schematic perspective view illustrating a modified example of hollowing out a single crystal substrate from the internally processed layer-forming single crystal substrate according to the present embodiment. FIG. 7 is a schematic perspective view illustrating a modified example of hollowing out the single crystal substrate from the internally processed layer-forming single crystal substrate according to the present embodiment. FIG. 8 is a modification of the internally processed layer-forming single crystal substrate according to the present embodiment, and is a schematic plan view showing a processing state for obtaining a plurality of single crystal substrates. FIG. 9 is a photographic view showing a cross section of the internally processed layer-forming single crystal member obtained under the processing condition 1 of the experimental example. FIG. 10 is a photographic view showing a cross section of the internally processed layer-forming single crystal member obtained under the processing condition 4 of the experimental example.
図１〜図５に示すように、本実施形態に係る内部加工層形成単結晶基板２０は、パルス状のレーザ光Ｂを加工対象単結晶基板１０の被照射面２０ｔから照射し単結晶基板内部で集光することで、この被照射面２０ｔから離間しかつこの被照射面２０ｔから基板の厚さ方向に円筒状（図４参照）またはテーパ状（円錐台状。図５参照）に広がる加工層２１と、その加工層２１の周囲外側および周囲内側に隣接する非加工部２２とを有する。この非加工部２２は、加工層２１の内側であるくり抜き対象部２４を有する。 As shown in FIGS. 1 to 5, the internally processed layer-forming single crystal substrate 20 according to the present embodiment irradiates the pulsed laser beam B from the irradiated surface 20t of the processing target single crystal substrate 10 to inside the single crystal substrate. By concentrating with, the processing is separated from the irradiated surface 20t and spreads from the irradiated surface 20t in a cylindrical shape (see FIG. 4) or a tapered shape (conical truncated cone shape, see FIG. 5) in the thickness direction of the substrate. It has a layer 21 and a non-processed portion 22 adjacent to the outer peripheral side and the inner peripheral side of the processed layer 21. The non-processed portion 22 has a hollowed-out target portion 24 inside the processed layer 21.
加工層２１には、レーザ光Ｂの集光によって形成された加工痕２１ｃが加工層２１に、一定の間隔で規則的に配列されている。 In the processing layer 21, processing marks 21c formed by condensing the laser beam B are regularly arranged in the processing layer 21 at regular intervals.
本実施形態では、以下のようにして内部加工層形成単結晶基板２０を製造する。レーザ集光手段としては、例えば図１に示すレーザ加工装置１２ｍを配置する。このレーザ加工装置１２ｍは、レーザ発振器、集光器を順次備え、またＸＹステージおよび回転ステージを備えている。また、集光器は複数のレンズが組み合わされた組レンズとなっており、集光性が高くされている。 In the present embodiment, the internally processed layer-forming single crystal substrate 20 is manufactured as follows. As the laser condensing means, for example, the laser processing apparatus 12 m shown in FIG. 1 is arranged. The laser processing device 12m is sequentially provided with a laser oscillator and a condenser, and also includes an XY stage and a rotation stage. In addition, the condenser is a set lens in which a plurality of lenses are combined, and the light collecting property is improved.
ここで、Ｚ方向は、レーザ加工装置１２ｍにおけるレーザ光の集光方向であり、かつ、加工対象単結晶基板１０の厚み方向となっている。そしてＸ方向はＺ方向に直交する方向であり、加工対象単結晶基板１０の半径方向となる。また加工対象単結晶基板１０は、例えば円盤状のシリコンウエハである。加工対象単結晶基板１０を保持する基板ホルダーは回転可能であり、加工対象単結晶基板１０をその中心軸まわりに一定の回転速度で回転差あせることが可能となっている。 Here, the Z direction is the focusing direction of the laser light in the laser processing apparatus 12 m and the thickness direction of the single crystal substrate 10 to be processed. The X direction is orthogonal to the Z direction, and is the radial direction of the single crystal substrate 10 to be processed. The single crystal substrate 10 to be processed is, for example, a disk-shaped silicon wafer. The substrate holder that holds the single crystal substrate 10 to be processed is rotatable, and the single crystal substrate 10 to be processed can be rotated at a constant rotation speed around its central axis.
ＸＹステージで移動させるものは加工単結晶基板１０であるが、レーザ光の照射側を移動させることも可能である。 What is moved in the XY stage is the processed single crystal substrate 10, but it is also possible to move the irradiation side of the laser beam.
（内部加工層単結晶基板の製造方法）
内部加工層単結晶基板２０を製造するには、図１に示すように、レーザ加工装置１２ｍを、加工対象単結晶基板１０の被照射面上に非接触に配置する工程を行う（第１工程）。なお、本明細書で加工対象単結晶基板とは、３次元形状の立体的な単結晶部材のうちの基板状部分も含む概念である。
(Manufacturing method of internal processing layer single crystal substrate)
In order to manufacture the internal processing layer single crystal substrate 20, as shown in FIG. 1, a step of arranging the laser processing apparatus 12m on the irradiated surface of the processing target single crystal substrate 10 in a non-contact manner is performed (first step). ). In the present specification, the single crystal substrate to be processed is a concept including a substrate-like portion of a three-dimensional three-dimensional single crystal member.
そして、図２（ａ）〜（ｃ）に示すように、回転ステージ上に固定、配置された加工対象単結晶基板１０を回転ステージの回転数で回転させつつレーザ光Ｂを照射することで、加工対象単結晶基板１０の内部にレーザ光Ｂを集光しつつ、レーザ光Ｂの集光位置を加工対象単結晶基板１０のくり抜き対象部の周囲方向に変化させることで、破断強度が低下した加工層２１をくり抜き対象部の周囲に形成する工程を行う（第２工程）。この時レーザ光Ｂは、例えばパルス幅が１μｓ以下のパルスレーザ光からなり、３００ｎｍ以上の波長が選択され、例えば加工対象単結晶基板１０がシリコンウエハの場合は、１０００ｎｍ以上の波長のＹＡＧレーザ等が好適に使用される。 Then, as shown in FIGS. 2A to 2C, the laser beam B is irradiated while rotating the single crystal substrate 10 to be processed fixed and arranged on the rotating stage at the rotation speed of the rotating stage. The breaking strength was reduced by changing the condensing position of the laser beam B toward the periphery of the hollowed-out target portion of the single crystal substrate 10 to be processed while condensing the laser beam B inside the single crystal substrate 10 to be processed. A step of forming the processed layer 21 around the hollowed-out target portion is performed (second step). At this time, the laser beam B is, for example, a pulsed laser beam having a pulse width of 1 μs or less, and a wavelength of 300 nm or more is selected. For example, when the single crystal substrate 10 to be processed is a silicon wafer, a YAG laser having a wavelength of 1000 nm or more or the like is selected. Is preferably used.
以下、内部加工層を形成する手順を詳細に説明する。図２（ａ）ではレーザ光Ｂ照射面とは反対側の加工対象単結晶基板１０の裏面（底面）側から照射を開始し、レーザ光Ｂの集光位置を、くり抜き対象部の周囲方向に変化させつつ徐々にレーザ光斜面側（Ｚ軸方向）へ移動させていく。このＺ軸方向への移動方法は集光器Ｇあるいは回転ステージＳの少なくとも一方を移動すればよい。加工対象単結晶基板１０の裏面（底面）側への最初の集光位置は、レーザ光Ｂの照射により形成される加工層２１が加工対象単結晶基板１０の裏面(底面)の表面に亀裂やアブレーションなどのダメージを与えない位置に設定することが望ましい。これは内部加工層形成単結晶基板から単結晶基板をくり抜く際に、クラックや割れなどの不具合発生を防止するためである。 Hereinafter, the procedure for forming the internal processed layer will be described in detail. In FIG. 2A, irradiation is started from the back surface (bottom surface) side of the single crystal substrate 10 to be processed on the side opposite to the laser beam B irradiation surface, and the focusing position of the laser beam B is set in the peripheral direction of the hollowed out target portion. The laser beam is gradually moved toward the slope side (Z-axis direction) while being changed. The method of moving in the Z-axis direction may be to move at least one of the condenser G and the rotating stage S. At the first condensing position on the back surface (bottom surface) of the single crystal substrate 10 to be processed, the processing layer 21 formed by irradiation with the laser beam B cracks on the surface of the back surface (bottom surface) of the single crystal substrate 10 to be processed. It is desirable to set it in a position that does not cause damage such as ablation. This is to prevent the occurrence of defects such as cracks and cracks when the single crystal substrate is hollowed out from the internally processed layer-forming single crystal substrate.
加工痕２１ｃを形成する間隔は、基板平面方向はレーザ光Ｂの発振繰り返し周波数と回転ステージの回転速度すなわち周速との関係で決定され、高さ（深さ）方向は集光位置のＺ軸方向の移動量により決定される。加工層２１は上記のように所定間隔にレーザ光Ｂを照射して、加工痕２１ｃが連続した加工領域として形成された領域として得られる。 The interval at which the machining marks 21c are formed is determined by the relationship between the oscillation repetition frequency of the laser beam B and the rotation speed, that is, the peripheral speed of the rotating stage in the substrate plane direction, and the Z axis of the focusing position in the height (depth) direction. It is determined by the amount of movement in the direction. The processed layer 21 is obtained as a region in which the processing marks 21c are formed as continuous processing regions by irradiating the laser beam B at predetermined intervals as described above.
レーザ光Ｂの照射手順としては、回転ステージ上に固定、配置した加工対象単結晶部材１０内部のＺ軸方向の位置を決定後に、先ず同心円の外径に沿ってにレーザ光Ｂを少なくとも１回転照射した後、レーザ加工装置１２ｍ方向のＺ軸方向に集光位置を移動してレーザ光Ｂを同様にて同心円の外径に沿って照射する。この時Ｚ軸方向への集光位置の移動は、加工対象単結晶部材１０の厚さ方向に対して垂直あるいはテーパ状に移動することにより、加工層２１は垂直状あるいはテーパ状に形成することができる。 As an irradiation procedure of the laser beam B, after determining the position in the Z-axis direction inside the single crystal member 10 to be processed fixed and arranged on the rotating stage, the laser beam B is first rotated at least once along the outer diameter of the concentric circles. After the irradiation, the condensing position is moved in the Z-axis direction in the 12 m direction of the laser processing device, and the laser beam B is similarly irradiated along the outer diameter of the concentric circles. At this time, the movement of the condensing position in the Z-axis direction is such that the processing layer 21 is formed in a vertical or tapered shape by moving in a vertical or tapered shape with respect to the thickness direction of the single crystal member 10 to be processed. Can be done.
この一連の動作を加工対象単結晶基板１０の表面近傍まで行うことにより、図２（ｃ）、図４に示すように加工層２１が得られる。この時、加工対象単結晶基板１０の表面近傍とは、レーザ光Ｂの集光位置から表面方向にクラックが延びて表面まで加工クラックが到達することで、加工クラックによってくり抜き加工が可能となる位置であり、しかも、該表面にレーザ光Ｂの照射による該表面に加工痕や亀裂あるいはアブレーションなどの状態が生じない位置である。 By performing this series of operations up to the vicinity of the surface of the single crystal substrate 10 to be processed, the processed layer 21 can be obtained as shown in FIGS. 2C and 4. At this time, the vicinity of the surface of the single crystal substrate 10 to be processed is a position where cracks extend from the condensing position of the laser beam B toward the surface and the processing cracks reach the surface, so that the processing cracks can be hollowed out. Moreover, it is a position where a state such as processing marks, cracks or ablation does not occur on the surface due to irradiation of the laser beam B on the surface.
加工対象単結晶基板１０の内部にレーザ光Ｂを照射すると集光によって生じる温度上昇に伴い加工痕は集光点から加工単結晶基板１０の表面方向に向かって延びることが分かっている。この温度上昇に伴う加工痕の延伸は単結晶基板１０内部の加工痕が一定状態で形成されず、特に加工対象単結晶基板１０の結晶方位方向に亀裂が生じてしまい、本発明の目的であるくり抜き加工において結晶方位方向への割れや破損が生じる。 It is known that when the inside of the single crystal substrate 10 to be processed is irradiated with the laser beam B, the processing marks extend from the focusing point toward the surface of the processed single crystal substrate 10 as the temperature rises due to the focusing. This stretching of the processing marks due to the temperature rise is an object of the present invention because the processing marks inside the single crystal substrate 10 are not formed in a constant state, and cracks are particularly generated in the crystal orientation direction of the single crystal substrate 10 to be processed. Cracks and breaks occur in the crystal orientation direction during the hollowing process.
従って、本発明おけるレーザ加工においては、上記した温度上昇を影響のない程度に抑制する必要がある。そのため、本発明では加工対象単結晶部材１０の深さ方向に集光点を移動させることは好ましくない。 Therefore, in the laser processing in the present invention, it is necessary to suppress the above-mentioned temperature rise to an extent that does not affect it. Therefore, in the present invention, it is not preferable to move the focusing point in the depth direction of the single crystal member 10 to be processed.
また、必要に応じて加工対象単結晶基板１０を冷却することも可能である。 It is also possible to cool the single crystal substrate 10 to be processed if necessary.
以上説明したように、本実施形態により、加工対象単結晶基板１０からそれよりも小さい寸法の単結晶基板２６を得ることを可能にする内部加工層形成単結晶基板２６を製造することができる。そして、くり抜き対象部２４のテーパ内側の面（図２では被照射面２０ｔ）側を力Ｆで押圧する等を行い、内部加工層形成単結晶基板２０からくり抜き対象部２４をくり抜くことで単結晶基板２６が得られる。なお、単結晶基板２６の外周面には、必要に応じて研磨等の加工を行う。 As described above, according to the present embodiment, it is possible to manufacture the internally processed layer-forming single crystal substrate 26 that makes it possible to obtain the single crystal substrate 26 having a smaller size from the processing target single crystal substrate 10. Then, the inner surface of the taper (irradiated surface 20t in FIG. 2) side of the hollowed-out target portion 24 is pressed by a force F, and the single crystal is hollowed out from the internal processed layer-forming single crystal substrate 20. The substrate 26 is obtained. The outer peripheral surface of the single crystal substrate 26 is subjected to processing such as polishing as necessary.
従って、本実施形態では、単結晶基板の寸法が使用予定の寸法よりも大きい場合、この単結晶基板を加工対象単結晶基板１０とし、加工対象単結晶基板１０よりも小さい寸法の単結晶基板２６を得ることで加工対象単結晶基板１０を再利用することができ、資源の有効活用が図られる。 Therefore, in the present embodiment, when the size of the single crystal substrate is larger than the size to be used, this single crystal substrate is set as the single crystal substrate 10 to be processed, and the single crystal substrate 26 having a size smaller than the single crystal substrate 10 to be processed. By obtaining the above, the single crystal substrate 10 to be processed can be reused, and resources can be effectively utilized.
レーザ光Ｂは、例えばパルス幅が１μｓ以下のパルスレーザ光からなり、９００ｎｍ以上の波長、好ましくは１０００ｎｍ以上の波長が選択され、ＹＡＧレーザ等が好適に使用される。 The laser beam B is composed of, for example, a pulsed laser beam having a pulse width of 1 μs or less, and a wavelength of 900 nm or more, preferably 1000 nm or more is selected, and a YAG laser or the like is preferably used.
なお、図３(ａ)および(ｂ)では、加工層２１には加工痕２１ｃが一列に配置されているように描いているが、実際には、加工層２１には複数の加工痕２１ｃが散りばめられていてもよい。これにより、くり抜き対象部２４を内部加工層形成単結晶基板２０からくり抜く際の作業が更に容易になる。また、加工対象単結晶基板１０の表面近傍である該表面にレーザ光Ｂの照射による該表面に加工痕や亀裂あるいはアブレーションなどの状態が生じないような照射となるように、本実施形態では、レーザ光Ｂの集光位置を、くり抜き対象部の周囲方向に変化させつつ徐々にレーザ光斜面側（Ｚ軸方向）へ移動させている。 In addition, in FIGS. 3A and 3B, the processing marks 21c are drawn as if they are arranged in a row on the processing layer 21, but in reality, the processing layer 21 has a plurality of processing marks 21c. It may be studded. As a result, the work of hollowing out the hollowed-out target portion 24 from the internally processed layer-forming single crystal substrate 20 becomes easier. Further, in the present embodiment, the surface of the single crystal substrate 10 to be processed is irradiated with the laser beam B so that no processing marks, cracks, ablation, or the like are generated on the surface. The condensing position of the laser beam B is gradually moved toward the laser beam slope side (Z-axis direction) while changing in the peripheral direction of the hollowed-out target portion.
また、第２工程後、あるいは第２工程中に、被照射面側または被照射面とは反対面側に、加工層２１へのクラックを発生し易くする切欠２８（図６、図７参照）を形成してもよい。これにより、切欠２８を広げるように内部加工層形成単結晶基板２０に力を加えると、切欠２８を起点としてから加工層２１へ応力が伝わり、基板表面にチッピングなどによる割れなどを発生させずに単結晶基板２６を得ることができる。 Further, after the second step or during the second step, a notch 28 (see FIGS. 6 and 7) that easily causes cracks in the processed layer 21 on the irradiated surface side or the surface opposite to the irradiated surface side. May be formed. As a result, when a force is applied to the internally processed layer-forming single crystal substrate 20 so as to widen the notch 28, stress is transmitted to the processed layer 21 from the notch 28 as a starting point, and cracks due to chipping or the like are not generated on the substrate surface. A single crystal substrate 26 can be obtained.
この場合、切欠２８を加工層２１に隣接する位置に形成すると、切欠２８から発生したクラック３０によって、加工層２１の隣接する加工痕２１ｃ同士で順次クラックが発生して行き易い。 In this case, if the notch 28 is formed at a position adjacent to the processed layer 21, cracks 30 generated from the notch 28 tend to sequentially generate cracks between the adjacent processing marks 21c of the processed layer 21.
切欠２８は、レーザ集光手段１２により加工痕２１ｃを追加形成したものであっても良いし、他の形成手段で形成してもよい。 The notch 28 may be formed by additionally forming a processing mark 21c by the laser condensing means 12, or may be formed by another forming means.
また、加工痕２１ｃを形成する位置が被照射面２０ｔに近くなるに従い、レーザ出力を徐々に低下させると、くり抜き対象部２４を良好な形状でくり抜く上で好ましい。 Further, it is preferable to gradually reduce the laser output as the position where the processing mark 21c is formed becomes closer to the irradiated surface 20t in order to hollow out the hollowed-out target portion 24 in a good shape.
１枚の加工対象単結晶基板１０から複数の単結晶基板２６をくり抜くことも可能である（例えば４枚の単結晶基板をくり抜く例として図８参照）。この場合、目的とする単結晶基板２０の寸法に応じて加工層２１を形成すればよく、その方法としては集光部１２を回転させてＺ軸方向へ移動させる方式などが採用できる。 It is also possible to hollow out a plurality of single crystal substrates 26 from one single crystal substrate 10 to be processed (see, for example, FIG. 8 as an example of hollowing out four single crystal substrates). In this case, the processed layer 21 may be formed according to the dimensions of the target single crystal substrate 20, and as a method thereof, a method of rotating the condensing unit 12 to move it in the Z-axis direction or the like can be adopted.
＜実験例＞
回転ステージ上に加工対象単結晶部材１０として直径１５０ｍｍ、厚さ６２５μｍの単結晶シリコンウエハ（結晶方位（１００）、鏡面）を吸着盤にて吸着固定し、加工対象単結晶基板１０の同心円として直径１００ｍｍの単結晶基板２６を得るために、内部加工層形成単結晶基板を作製した。なお、本実験例では、集光装置に収差補正環を備えさせ、条件１〜４において調整量を０．６ｍｍとした。
<Experimental example>
A single crystal silicon wafer (crystal orientation (100), mirror surface) having a diameter of 150 mm and a thickness of 625 μm is adsorbed and fixed on the rotating stage as the single crystal member 10 to be processed, and the diameter is formed as concentric circles of the single crystal substrate 10 to be processed. In order to obtain a 100 mm single crystal substrate 26, an internally processed layer-formed single crystal substrate was produced. In this experimental example, the condensing device was provided with an aberration correction ring, and the adjustment amount was set to 0.6 mm under conditions 1 to 4.
ここで、ドットピッチとは加工痕２１ｓの円周方向のピッチのことであり回転ステージ上で加工する場合は周速と周波数との関係から任意に設定することができる。また、ラインピッチとは、図１で示したＺ方向（内部加工層形成単結晶基板２０の厚み方向）のピッチのことである。 Here, the dot pitch is the pitch in the circumferential direction of the machining marks 21s, and can be arbitrarily set from the relationship between the peripheral speed and the frequency when machining on the rotating stage. The line pitch is the pitch in the Z direction (thickness direction of the internally processed layer-forming single crystal substrate 20) shown in FIG.
またデフォーカス量とは、加工対象単結晶基板１０の表面を基準（０）として集光位置を加工対象単結晶基板１０の内部（裏面）方向への集光位置の移動量であり、マイナス表記は内部方向を表す。 The defocus amount is the amount of movement of the focusing position toward the inside (back surface) of the processing target single crystal substrate 10 with the front surface of the processing target single crystal substrate 10 as a reference (0), and is expressed as a minus. Represents the internal direction.
本発明者は、加工層２１を形成する際のレーザ光の照射条件を検討するために、加工条件１〜４の条件で、厚み６２５μｍのシリコンウエハに、レーザ加工装置１２ｍからレーザ光Ｂをデフォーカス量（μｍ）：−１５６〜０ で照射して加工層２１を形成した。そして、加工層２１の断面を電子顕微鏡で観察し、比較的良好な断面形状であることを確認した（例えば、図９、図１０参照）。 In order to examine the irradiation conditions of the laser beam when forming the processed layer 21, the present inventor applies the laser beam B from the laser processing apparatus 12 m to a silicon wafer having a thickness of 625 μm under the conditions of processing conditions 1 to 4. The processed layer 21 was formed by irradiating with a focus amount (μm): -156 to 0. Then, the cross section of the processed layer 21 was observed with an electron microscope, and it was confirmed that the cross-sectional shape was relatively good (see, for example, FIGS. 9 and 10).
さらに本発明者は、加工条件３を用いて、厚み６２５μｍ、直径１５０ｍｍのシリコンウエハに、レーザ加工装置１２ｍからレーザ光Ｂを以下の条件で照射して厚さ方向の平均直径が３０ｍｍ径となるように加工層２１を形成した。更に、被照射面２０ｔ付近の加工痕２１ｃの周辺にガラス切りで切欠状の加工を加え、ウエハのくり抜きを行い、図１１に示すウエハを得た。 Further, the present inventor irradiates a silicon wafer having a thickness of 625 μm and a diameter of 150 mm with laser light B from a laser processing apparatus 12 m under the following conditions using the processing condition 3, and the average diameter in the thickness direction becomes 30 mm. The processed layer 21 was formed as described above. Further, a notch-like processing was performed by cutting glass around the processing mark 21c near the irradiated surface 20t, and the wafer was hollowed out to obtain the wafer shown in FIG.
なお、この時のデフォーカス量は−１３６μｍ〜２０μｍであり、内部加工層の深さ方向の上限はウエハ表面から１１０μｍの位置にあり、レーザ照射によるウエハ表面のダメージは生じなかった。 The amount of defocus at this time was -136 μm to 20 μm, the upper limit of the internal processed layer in the depth direction was at a position 110 μm from the wafer surface, and the wafer surface was not damaged by laser irradiation.
なお、本実施形態では、加工層２１の外形や内形を円状以外（例えば四角状）とすることも可能である。 In this embodiment, the outer shape and inner shape of the processed layer 21 can be other than circular (for example, square).
また、加工痕２１ｃを形成する際、隣接する加工痕２１ｃ同士の間にクラックが順次発生するように形成しても良いし、遅れ破壊のように少し時間をおいてから加工痕２１ｃ同士を繋ぐクラックが発生するように形成してもよい。これにより、くり抜き対象部２４を極めて容易にくり抜くことができる。 Further, when forming the machining marks 21c, the machining marks may be formed so that cracks are sequentially generated between the adjacent machining marks 21c, or the machining marks 21c are connected to each other after a short time such as delayed fracture. It may be formed so as to generate cracks. As a result, the hollowing target portion 24 can be hollowed out extremely easily.
本発明により、単結晶基板からそれよりも小さい寸法の単結晶基板を得ることを可能にすることから、薄く切り出された単結晶基板は、Ｓｉ基板（シリコン基板）であれば、太陽電池に応用可能であり、また、ＳｉＣなどであれば、ＳｉＣ系パワーデバイスなどに応用可能であり、透明エレクトロニクス分野、照明分野、ハイブリッド／電気自動車分野など幅広い分野において適用可能である。 Since the present invention makes it possible to obtain a single crystal substrate having a smaller size from the single crystal substrate, the thinly cut single crystal substrate can be applied to a solar cell if it is a Si substrate (silicon substrate). It is possible, and if it is SiC or the like, it can be applied to a SiC power device or the like, and can be applied to a wide range of fields such as a transparent electronics field, a lighting field, and a hybrid / electric vehicle field.
１０ 加工対象単結晶基板１２ レーザ集光手段１２ｍ レーザ加工装置２０ 内部加工層形成単結晶基板２０ｔ 被照射面２１ 加工層２１ｃ 加工痕２４ くり抜き対象部２６ 単結晶基板２８ 切欠３０ クラックＢ レーザ光 10 Single crystal substrate to be processed 12 Laser condensing means 12m Laser processing device 20 Internal processing layer formation Single crystal substrate 20t Irradiated surface 21 Processing layer 21c Processing mark 24 Hollow target part 26 Single crystal substrate 28 Notch 30 Crack B Laser light
Claims (6)
前記レーザ集光手段により前記加工対象単結晶基板内部にレーザ光を集光しつつ、レーザ光の集光位置を前記加工対象単結晶基板のくり抜き対象部の周囲に沿って周囲方向に変化させることで、前記くり抜き対象部を取り囲む破断強度が低下した加工層を前記くり抜き対象部の周囲に形成する第２工程と、
を備え、前記第２工程において、レーザ光の集光位置を被照射面とは反対面側から被照射面側に徐々に移動させていき、加工痕を形成する位置が被照射面に近くなるに従い、レーザ出力を徐々に低下させ、レーザ光の集光位置から被照射面の方向にクラックが延びて被照射面まで加工クラックが到達することでくり抜き加工が可能となる位置であり、しかも、被照射面にレーザ光の照射による加工痕、亀裂又はアブレーションが生じないような被照射面の近傍までレーザ光を照射することを特徴とする内部加工層形成単結晶基板の製造方法。 The first step of arranging the laser condensing means for condensing the laser light on the irradiated surface of the single crystal substrate to be processed in a non-contact manner, and
While condensing the laser light inside the processing target single crystal substrate by the laser condensing means, the condensing position of the laser light is changed in the peripheral direction along the periphery of the hollowed out target portion of the processing target single crystal substrate. In the second step of forming a processed layer having a reduced breaking strength surrounding the hollowed-out target portion around the hollowed-out target portion.
In the second step, the position where the laser beam is focused is gradually moved from the side opposite to the irradiated surface to the irradiated surface side, and the position where the processing mark is formed becomes closer to the irradiated surface. Therefore, the laser output is gradually reduced, and the crack extends from the position where the laser light is focused toward the surface to be irradiated, and the processing crack reaches the surface to be irradiated, so that the hollowing process is possible. A method for producing an internally processed layer-forming single crystal substrate, which comprises irradiating an irradiated surface with a laser beam to the vicinity of the irradiated surface so that processing marks, cracks or ablation due to the irradiation of the laser beam are not generated.
前記レーザ集光手段により前記加工対象単結晶基板内部にレーザ光を集光しつつ、レーザ光の集光位置を前記加工対象単結晶基板のくり抜き対象部の周囲に沿って周囲方向に変化させることで、前記くり抜き対象部を取り囲む破断強度が低下した加工層を前記くり抜き対象部の周囲に形成する第２工程と、
前記加工層から破断させて前記くり抜き対象部をくり抜く第３工程と、
を備え、前記第２工程において、レーザ光の集光位置を被照射面から反対面側から被照射面側に徐々に移動させていき、加工痕を形成する位置が被照射面に近くなるに従い、レーザ出力を徐々に低下させ、レーザ光の集光位置から被照射面の方向にクラックが延びて被照射面まで加工クラックが到達することでくり抜き加工が可能となる位置であり、しかも、被照射面にレーザ光の照射による加工痕、亀裂又はアブレーションが生じないような被照射面の近傍までレーザ光を照射することを特徴とする単結晶基板の製造方法。 The first step of arranging the laser condensing means for condensing the laser light on the irradiated surface of the single crystal substrate to be processed in a non-contact manner, and
While condensing the laser light inside the processing target single crystal substrate by the laser condensing means, the condensing position of the laser light is changed in the peripheral direction along the periphery of the hollowed out target portion of the processing target single crystal substrate. In the second step of forming a processed layer having a reduced breaking strength surrounding the hollowed-out target portion around the hollowed-out target portion.
The third step of breaking from the processed layer and hollowing out the hollowed-out target portion, and
In the second step, the position where the laser beam is focused is gradually moved from the irradiated surface to the opposite surface side to the irradiated surface side, and as the position where the processing mark is formed becomes closer to the irradiated surface. , The laser output is gradually reduced, cracks extend from the position where the laser light is focused toward the surface to be irradiated, and the processing cracks reach the surface to be irradiated, so that hollowing can be performed. A method for producing a single crystal substrate, which comprises irradiating an irradiated surface with a laser beam to the vicinity of the irradiated surface so that processing marks, cracks or ablation due to the irradiation of the laser beam are not generated.
前記第３工程では、前記切欠を広げるように力を加えることで前記クラックを発生させることを特徴とする請求項５に記載の単結晶基板の製造方法。 Before performing the third step, a notch is formed on the irradiated surface side or the surface opposite to the irradiated surface so that cracks in the processed layer are likely to occur.
The method for manufacturing a single crystal substrate according to claim 5, wherein in the third step, the crack is generated by applying a force so as to widen the notch.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006245043A (en) * | 2005-02-28 | 2006-09-14 | Toyoda Gosei Co Ltd | Method of manufacturing group iii nitride-based compound semiconductor element, and light emitting element |
| JP2007165848A (en) * | 2005-11-16 | 2007-06-28 | Denso Corp | Method of manufacturing semiconductor chip |
| JP2011167718A (en) * | 2010-02-18 | 2011-09-01 | Saitama Univ | Apparatus and method for machining inside of substrate |
| JP2011206838A (en) * | 2010-03-30 | 2011-10-20 | Hamamatsu Photonics Kk | Laser beam machining method |
| JP2012000636A (en) * | 2010-06-16 | 2012-01-05 | Showa Denko Kk | Laser beam machining method |
| WO2012164649A1 (en) * | 2011-05-27 | 2012-12-06 | 浜松ホトニクス株式会社 | Laser machining method |
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006245043A (en) * | 2005-02-28 | 2006-09-14 | Toyoda Gosei Co Ltd | Method of manufacturing group iii nitride-based compound semiconductor element, and light emitting element |
| JP2007165848A (en) * | 2005-11-16 | 2007-06-28 | Denso Corp | Method of manufacturing semiconductor chip |
| JP2011167718A (en) * | 2010-02-18 | 2011-09-01 | Saitama Univ | Apparatus and method for machining inside of substrate |
| JP2011206838A (en) * | 2010-03-30 | 2011-10-20 | Hamamatsu Photonics Kk | Laser beam machining method |
| JP2012000636A (en) * | 2010-06-16 | 2012-01-05 | Showa Denko Kk | Laser beam machining method |
| WO2012164649A1 (en) * | 2011-05-27 | 2012-12-06 | 浜松ホトニクス株式会社 | Laser machining method |
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