JP4820508B2 - Sputtering target and manufacturing method thereof, sputtering apparatus, thin film manufacturing method, electronic component manufacturing method - Google Patents

Description

【００４８】
表１から明らかなように、実施例１〜３による各Ｔｉスパッタリングターゲットによれば、比較例１〜３のＴｉスパッタリングターゲットに比べてダスト発生量が低減している。特に、ターゲットライフ近くのダスト発生量が大幅に低減していることが分かる。
【００４９】
実施例４
Ｔｉターゲットの表面外周部と側面部、さらにバッキングプレートの露出表面に、それぞれ膜厚が5μm、20μm、50μm、100μmのＴｉ薄膜からなる再付着粒子剥離防止膜をアークイオンプレーティング法により形成する以外は、実施例３と同様にしてそれぞれスパッタリングターゲットを作製した。これらのスパッタリングターゲットについて、実施例３と同一条件下で成膜試験を実施し、100ロット後、150ロット後、200ロット後の各Ｔｉ薄膜上の0.2μm以上のダスト数（パーティクル数）をそれぞれ測定した。それらの測定結果を表２に示す。なお、表２には再付着粒子剥離防止膜（Ｔｉ薄膜）の表面粗さを併せて示す。
【００５０】
【表２】

【００５１】
表２から明らかなように、実施例３および実施例４の試料1による各Ｔｉスパッタリングターゲットはダスト発生量が少ないのに対し、Ｔｉ薄膜の膜厚を厚くした実施例４の試料2〜4による各スパッタリングターゲットはダスト発生量が増加している。これは、実施例４の試料2〜4ではＴｉ薄膜の表面粗さが膜厚の増大に伴って大きくなっているため、膜表面の凸部の影にあたる部分に付着した再付着粒子が脱落したり、あるいは膜表面の凸部先端に集中的に再付着粒子が堆積して膜ストレスが大きくなることで、ダストの発生数が実施例３や実施例４の試料1に比べて増加したものと考えられる。この結果から分かるように、再付着粒子剥離防止膜の膜厚は1〜10μmの範囲とすることが好ましい。
【００５２】
実施例５
再付着粒子剥離防止膜を形成する前に、Ｔｉターゲットの表面にエッチング処理を施して加工歪層などの除去および表面清浄化を行った後、膜厚3μmのＴｉ薄膜からなる再付着粒子剥離防止膜をアークイオンプレーティング法により形成する以外は、実施例３と同様にしてスパッタリングターゲットを作製した。このスパッタリングターゲットについて、実施例３と同一条件下で成膜試験を実施し、100ロット後、150ロット後、200ロット後の各Ｔｉ薄膜上の0.2μm以上のダスト数をそれぞれ測定した。その測定結果を表３に示す。なお、表３には再付着粒子剥離防止膜（Ｔｉ薄膜）の表面粗さを併せて示す。
【００５３】
【表３】

【００５４】
表３から明らかなように、実施例５のスパッタリングターゲットは、実施例３のスパッタリングターゲットに比べてダスト発生量が若干低下している。このことから分かるように、再付着粒子剥離防止膜の形成面（ターゲット本体の表面）は、予め加工歪層などを除去した清浄な面であることが好ましい。
【００５５】
実施例６
表面を鏡面加工したＴｉターゲット（試料1）と表面を鏡面加工およびエッチング処理したＴｉターゲット（試料2）をそれぞれ用意し、これらの表面外周部と側面部に膜厚3μmのＴｉ薄膜からなる再付着粒子剥離防止膜をアークイオンプレーティング法により形成する以外は、実施例３と同様にしてスパッタリングターゲットを作製した。これらのスパッタリングターゲットについて、実施例３と同一条件下で成膜試験を実施し、100ロット後、150ロット後、200ロット後の各Ｔｉ薄膜上の0.2μm以上のダスト数をそれぞれ測定した。それらの測定結果を表４に示す。なお、表４には再付着粒子剥離防止膜（Ｔｉ薄膜）の表面粗さを併せて示す。
【００５６】
【表４】

【００５７】
表４から明らかなように、実施例６の各スパッタリングターゲットは、実施例３のスパッタリングターゲットに比べてダスト発生量が若干低下している。このことから分かるように、再付着粒子剥離防止膜の形成面（ターゲット本体の表面）は平滑な面であることが好ましい。
【００５８】
実施例７
まず、Ｔａターゲット（ターゲット本体）となる純度5NのＴａ円板とバッキングプレートとなるＡｌ合金（6061）板とをホットプレスにより拡散接合した。これらを所望のターゲット形状およびバッキングプレート形状に機械加工した。具体的には、Ｔａターゲットは外径250mm、厚さ15mmとした。バッキングプレートは外径300mmとした。
【００５９】
次に、Ｔａターゲット表面の内径240mmの部分を被覆するようにマスキングした。すなわち、Ｔａターゲット表面の外周5mm幅の部分と側面部を露出させるように、マスキング処理を施した。このマスキングを介してＣＶＤ法により膜厚約5μmのＴａ薄膜を、再付着粒子剥離防止膜としてＴａターゲットの表面外周部と側面部、さらにバッキングプレートの露出表面に形成した。このようにして再付着粒子剥離防止膜をＣＶＤ法により形成したＴａスパッタリングターゲットを後述する成膜試験に供した。
【００６０】
実施例８
Ｔａターゲットの表面外周部と側面部、さらにバッキングプレートの露出表面に、再付着粒子剥離防止膜（膜厚約5μmのＴａ薄膜）をスパッタリング法により形成する以外は、実施例７と同様にしてＴａスパッタリングターゲットを作製した。この再付着粒子剥離防止膜をスパッタリング法により形成したＴａスパッタリングターゲットを後述する成膜試験に供した。
【００６１】
実施例９
Ｔａターゲットの表面外周部と側面部、さらにバッキングプレートの露出表面に、再付着粒子剥離防止膜（膜厚約3μmのＴａ薄膜）をアークイオンプレーティング法により形成する以外は、実施例７と同様にしてＴａスパッタリングターゲットを作製した。ここで、アークイオンプレーティング法により再付着粒子剥離防止膜を形成する前処理として、膜形成前のＴａターゲットを真空装置に配置して2.4×10^-3Paまで真空排気した後、300℃に予熱してＡｒボンバードクリーニングを30分間行い、さらにＴａボンバードクリーニングを10分間行った。このようにして再付着粒子剥離防止膜をアークイオンプレーティング法により形成したＴａスパッタリングターゲットを後述する成膜試験に供した。
【００６２】
比較例４
Ｔａターゲットの表面外周部と側面部、さらにバッキングプレートの露出表面に何等処理を施さない以外は、実施例７と同様にしてＴａスパッタリングターゲットを作製した。この再付着粒子の剥離防止処理を施していないＴａスパッタリングターゲットを後述する成膜試験に供した。
【００６３】
比較例５
Ｔａターゲットの表面外周部と側面部、さらにバッキングプレートの露出表面に対してブラスト処理のみを施す以外は、実施例７と同様にしてＴａスパッタリングターゲットを作製した。この再付着粒子の剥離防止処理としてブラスト処理を施したＴａスパッタリングターゲットを後述する成膜試験に供した。
【００６４】
比較例６
Ｔａターゲットの表面外周部と側面部、さらにバッキングプレートの露出表面に、溶射法により膜厚約5μmのＴａ薄膜を形成する以外は、実施例７と同様にしてＴａスパッタリングターゲットを作製した。この再付着粒子の剥離防止処理として溶射膜の形成を行ったＴａスパッタリングターゲットを後述する成膜試験に供した。
【００６５】
上述した実施例７〜９および比較例４〜６による各Ｔａスパッタリングターゲットを用いて、スパッタ圧4×10^{- １}Pa、スパッタ電流5A、Ａｒ流量5sccm、Ｎ₂流量3sccmの条件でマグネトロンスパッタリングを行って、6インチＳｉウェハー上にＴａＮ薄膜を形成した。そして、100ロット後、150ロット後、200ロット後の各ＴａＮ薄膜上の0.2μm以上のダスト（パーティクル）数をパーティクルカウンタでそれぞれ測定した。それらの測定結果を表５に示す。
【００６６】
【表５】

【００６７】
表５から明らかなように、実施例７〜９による各Ｔａスパッタリングターゲットによれば、比較例４〜６のＴａスパッタリングターゲットに比べてダスト発生量が低減している。特に、ターゲットライフ近くのダスト発生量が大幅に低減していることが分かる。
【００６８】
実施例１０
Ｔａターゲットの表面外周部と側面部、さらにバッキングプレートの露出表面に、それぞれ膜厚が5μm、20μm、50μm、100μmのＴａ薄膜からなる再付着粒子剥離防止膜をアークイオンプレーティング法により形成する以外は、実施例９と同様にしてそれぞれスパッタリングターゲットを作製した。これらのスパッタリングターゲットについて、実施例９と同一条件下で成膜試験を実施し、100ロット後、150ロット後、200ロット後の各ＴａＮ膜上の0.2μm以上のダスト数（パーティクル数）をそれぞれ測定した。それらの測定結果を表６に示す。なお、表６には再付着粒子剥離防止膜（Ｔａ薄膜）の表面粗さを併せて示す。
【００６９】
【表６】

【００７０】
実施例１１
再付着粒子剥離防止膜を形成する前に、Ｔａターゲットの表面にエッチング処理を施して加工歪層などの除去および表面清浄化を行った後、膜厚3μmのＴａ薄膜からなる再付着粒子剥離防止膜をアークイオンプレーティング法により形成する以外は、実施例９と同様にしてスパッタリングターゲットを作製した。このスパッタリングターゲットについて、実施例９と同一条件下で成膜試験を実施し、100ロット後、150ロット後、200ロット後の各ＴａＮ膜上の0.2μm以上のダスト数をそれぞれ測定した。その測定結果を表７に示す。なお、表７には再付着粒子剥離防止膜（Ｔａ薄膜）の表面粗さを併せて示す。
【００７１】
【表７】

【００７２】
実施例１２
表面を鏡面加工したＴａターゲット（試料1）と表面を鏡面加工およびエッチング処理したＴａターゲット（試料2）をそれぞれ用意し、これらの表面外周部と側面部に膜厚3μmのＴａ薄膜からなる再付着粒子剥離防止膜をアークイオンプレーティング法により形成する以外は、実施例９と同様にしてスパッタリングターゲットを作製した。これらのスパッタリングターゲットについて、実施例９と同一条件下で成膜試験を実施し、100ロット後、150ロット後、200ロット後の各ＴａＮ膜上の0.2μm以上のダスト数をそれぞれ測定した。それらの測定結果を表８に示す。なお、表８には再付着粒子剥離防止膜（Ｔａ薄膜）の表面粗さを併せて示す。
【００７３】
【表８】

【００７４】
【発明の効果】
以上説明したように、本発明のスパッタリングターゲットによれば、それ自体からの再付着物の剥離、脱落を有効に抑制し得るため、この再付着物の剥離、脱落に起因するダストの発生を大幅に低減することができる。従って、高品質のスパッタ膜を再現性よく提供することが可能となる。
【図面の簡単な説明】
【図１】 本発明の第１の実施形態によるスパッタリングターゲットの概略構成を示す断面図である。
【図２】 一般的なマグネトロンスパッタリング装置の構成を模式的に示す図である。
【図３】 本発明の第２の実施形態によるスパッタリングターゲットの概略構成を示す断面図である。
【図４】 図３に示すスパッタリングターゲットの変形例を示す断面図である。
【符号の説明】
１……ターゲット本体
２……バッキングプレート
３、７……スパッタリングターゲット
４……再付着粒子剥離防止膜[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a sputtering target used when forming wiring films, electrodes, element constituent films and the like of various electronic components.Its manufacturing method,Sputtering equipment, thin filmManufacturing method, Electronic componentsManufacturing methodAbout.
[0002]
[Prior art]
In manufacturing semiconductor components, liquid crystal components, and the like, sputtering is applied to the formation of various thin films used as wirings, electrodes, and the like. Specifically, a thin film of conductive metal such as Al, Cu, Ti, Mo, W, or Mo—W alloy by applying a sputtering method onto a deposition substrate such as a semiconductor substrate or a glass substrate, MoSi₂, WSi₂TiSi₂A thin film of a conductive metal compound such as TiN or TaN is formed, and these thin films are used as wiring, electrodes, barrier layers, and the like.
[0003]
The sputtering method is a film forming method in which the surface of a sputtering target is impacted by charged particles, sputtered particles are knocked out of the target, and the sputtered particles are deposited on a substrate arranged to face the target to form a thin film. As a sputtering target used when such a film forming method is applied, a structure in which a target body made of a film forming material is held by a substrate called a backing plate is generally applied.
[0004]
By the way, in the film-forming process using the conventional sputtering target as described above, the generation of dust due to the target becomes serious as the integration, reliability, and function of semiconductor elements and the like progress. Recognized as a problem. The dust mentioned here is, for example, fine particles (particles) with a diameter of 0.2 μm or more. If such fine particles are mixed in the thin film, the cause of short-circuiting between wirings or poor wiring opening Therefore, the manufacturing yield of electronic parts such as semiconductor elements and liquid crystal display elements is reduced.
[0005]
For example, an industrially efficient magnetron sputtering method is mainly applied, and an erosion part and a non-erosion part exist in the target body from the principle. Some of the sputtered particles reach the substrate, some fly to the periphery, and some return to the target body again. Of the particles returning to the target side, particles adhering to the non-erosion part (reattachment particles) are basically not sputtered again, so that the reattachment particles accumulate as the progress of sputtering progresses. When the deposit (reattachment film) of the reattachment particles is peeled off due to some factor, it is mixed in the thin film formed as dust.
[0006]
As described above, peeling of the reattachment is one of the causes of dust generation. In order to prevent such dust, the surface roughness of the non-erosion part is made rougher than that of the erosion part to prevent the reattachment from peeling and dropping (see, for example, JP-A-6-306597). A blast particle is implanted into the portion to prevent the reattachment from peeling and dropping by an anchor effect (see, for example, JP-A-9-76843), and a sprayed film is formed on the surface of the components of the sputtering apparatus (JP-A-9-272965). Various measures have been taken, such as the Japanese Patent Gazette.
[0007]
[Problems to be solved by the invention]
However, although the conventional dust reduction measures as described above are recognized to have a certain effect, the dust tends to increase as sputtering progresses to near the target life. For this reason, it is required to more effectively suppress the peeling and dropping of the reattachment deposited in the non-erosion region of the sputtering target and further reduce the generation of dust.
[0008]
In particular, in recent semiconductor elements, wiring widths of 0.2 μm or less, 0.13 μm or 0.1 μm are required in order to achieve a degree of integration such as 256M and 1G, and some practical applications have been made. It is being advanced. In such a narrowed high-density wiring, even if ultra-fine particles are mixed, wiring defects and the like are caused. Therefore, the amount of dust generated is increased in increasing the manufacturing yield of highly integrated semiconductor devices. Must be significantly reduced. Therefore, there is a strong demand for suppressing the separation and dropping of the reattachment that contributes to dust generation.
[0009]
The present invention has been made to cope with such a problem, and it is possible to reduce the generation of dust by effectively suppressing the separation and dropping of the reattachment from the non-erosion region or the like of the target body. It is an object of the present invention to provide a sputtering target and a sputtering apparatus using the sputtering target.
[0010]
[Means for Solving the Problems]
The present inventors have observed and examined in detail the form of the reattachment adhered to and deposited on the non-erosion region of the target main body and the exposed surface of the backing plate. By forming a relatively smooth metal thin film or metal compound thin film such as a sputtered film or a CVD film on the surface of the substrate in advance as a surface treatment, the reattachment is densified and the adhesion strength with the substrate is improved. As a result, it has been found that it is possible to suppress the generation of dust due to peeling and dropping of the reattachment even in the latter stage of sputtering.
[0011]
  The sputtering target of the present invention is made based on such knowledge. That is, the first sputtering target of the present invention, as described in claim 1, is provided on at least a part of the target main body and the non-erosion region of the target main body, and is reattached by the PVD method or the CVD method. With particle peeling prevention filmThe film thickness of the reattachment particle peeling prevention film is 3 to 10 μm, and the surface roughness of the film surface is 1 μm or less in terms of arithmetic average roughness Ra.It is characterized by that.
[0012]
  As described in claim 3, the second sputtering target of the present invention is provided on at least a part of the surface of the target main body, the backing plate that supports the target main body, and the backing plate. Re-adhesion particle peeling prevention film formed by the methodThe film thickness of the reattachment particle peeling prevention film is 3 to 10 μm, and the surface roughness of the film surface is 1 μm or less in terms of arithmetic average roughness Ra.It is characterized by that.
[0013]
In the sputtering target of the present invention, the reattachment particle peeling prevention film is preferably made of a metal thin film or a metal compound thin film formed by a sputtering method, an ion plating method, or a CVD method. Further, as a specific constituent material, as described in claim 6, a metal thin film or a metal compound thin film containing a metal element constituting the target body is preferable.
[0014]
Moreover, the sputtering apparatus of the present invention includes, as described in claim 8, a vacuum vessel, a film formation sample holding portion disposed in the vacuum vessel, and the film formation sample holding portion in the vacuum vessel. And a target unit disposed opposite to the target unit, the target unit includes the above-described sputtering target of the present invention.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, modes for carrying out the present invention will be described.
FIG. 1 is a sectional view showing a schematic structure of a sputtering target according to the first embodiment of the present invention. In the figure, reference numeral 1 denotes, for example, a disk-shaped target body made of various film materials such as metal materials and compound materials. This target body 1 is supported by a backing plate 2, and a sputtering target 3 is constituted by these.
[0016]
The backing plate 2 is a support member for the target body 1 and has a function as a cooling member for suppressing a temperature rise of the target body 1 due to ion bombardment (sputtering heat). For this reason, for example, oxygen-free copper or Al alloy having high thermal conductivity is used as a constituent material of the backing plate 2, and a cooling pipe (not shown) is built in the backing plate 2.
[0017]
The constituent material of the target body 1 is not particularly limited, and various simple metal materials, alloy materials, metal compound materials, and the like are used depending on the purpose of use of the sputtering target. Specific examples of the constituent material of the target body 1 include Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Pt, Ag, Ir, Ru, Fe, Ni, Co, Al, Cu, Si, and A single element of a metal element selected from Ge, or an alloy or compound containing the metal element described above can be used.
[0018]
Here, FIG. 2 schematically shows a configuration of a general magnetron sputtering apparatus. In a general magnetron sputtering apparatus, a sputtering target 3 and a substrate 5 are disposed to face each other, an electric field E is applied between them, and a target is formed by a magnet 6 disposed on the back surface side of the sputtering target 3 in a form orthogonal thereto. A magnetic field M is generated on the surface.
[0019]
Due to the action of the magnetic field M and the electric field E, electrons cause a cyclonic motion to generate high-density plasma in the target surface and in the upper magnetic field, and erosion of the target surface in the region surrounded by the magnetic field M progresses. Go. On the other hand, the target region deviated from the magnetic field M, that is, the central portion A, the outer peripheral portion B, and the side surface portion C of the surface (sputtering surface) of the target main body 1 are not sputtered. The separation and dropping of the reattached particles accumulated in the non-erosion region is a cause of dust generation.
[0020]
Therefore, in the sputtering target 3 shown in FIG. 1, the reattachment particle peeling preventing film 4 is formed in the non-erosion region of the target body 1, that is, in the surface central portion, the surface outer peripheral portion, and the side surface portion of the target body 1. Note that the reattachment particle peeling prevention film 4 does not necessarily have to be formed on the entire non-erosion region of the target body 1, and even when formed on a part thereof, the effect is exhibited. For example, even if the reattachment particle peeling prevention film 4 is formed only on the outer peripheral portion of the surface of the target main body 1 where peeling and dropping of the reattachment particles are a problem, an effect is shown for suppressing dust.
[0021]
The reattachment particle peeling prevention film 4 is made of a metal thin film or a metal compound thin film formed by a PVD (Physical Vapor Deposition) method or a CVD (Chemical Vapor Deposition) method. . The conventional sprayed film has a rough surface, and the particles attached to the shadowed portion of the convex part (mainly the surface opposite to the side where the reattached particles are deposited) tend to peel off, whereas the PVD method In addition to being a thin film itself, the reattachment particle peeling prevention film 4 formed by the CVD method has a smoother surface compared to a conventional sprayed film, etc. On the other hand, it shows good conformability, and the reattached particles can be deposited densely and relatively smoothly.
[0022]
In this way, by forming the reattachment particle peeling prevention film 4 as a surface treatment in advance in the non-erosion region of the target main body 1, the adhesion strength and reattachment of the reattachment itself to be deposited and deposited thereon The adhesion strength with the base (reattached particle peeling prevention film 4) can be increased. By these, it becomes possible to suppress effectively the peeling and dropping of the reattachment. That is, it is possible to greatly reduce the generation of dust due to peeling and dropping of the reattachment.
[0023]
As a method for forming the reattachment particle peeling prevention film 4, a vacuum deposition method, a molecular beam epitaxy (MBE) method, an ion plating method, a sputtering method, a laser deposition method, a PVD method such as an ion beam deposition method, or a heat A CVD method such as a CVD method, a plasma CVD method, and a photo CVD method can be applied. In particular, a sputtering method and an ion plating method that have excellent adhesion strength with the base (target body 1) and that have a low film formation cost. Alternatively, it is preferable to apply various CVD methods.
[0024]
Here, in the case of applying an ion plating method as a method for forming the reattachment particle peeling prevention film 4, in order to improve the adhesion of the reattachment particle peeling prevention film 4 by cleaning the surface of the target body 1, It is preferable to perform bombard cleaning on the surface of the target body 1. For example, when the target body 1 is made of Ti, the target body 1 is preheated in a vacuum, and after Ar bombard cleaning and Ti bombard cleaning are performed, the reattachment particle peeling prevention made of Ti or TiN thin film is prevented. It is preferable to form the film 4.
[0025]
Furthermore, it is preferable to perform at least one of rotary polishing and polishing in advance on the surface of the target body 1 on which the reattachment particle peeling prevention film 4 is formed, and in particular, polishing is performed after the rotary polishing is performed. Is preferred. In the present invention, after the target body 1 is polished, it is preferable to further perform a surface treatment such as wet etching, dry etching, or reverse sputtering. For wet etching, for example, a potassium ferricyanide (red blood potassium) solution or the like can be used as an etching solution. In dry etching, for example, CF_Four/ O₂A mixed gas or the like can be used as an etching gas.
[0026]
As described above, by subjecting the target body 1 to the above-described polishing treatment or surface treatment in advance before forming the reattachment particle peeling prevention film 4, the internal distortion of the crystal plane on the surface of the target body 1 is reduced. It is possible to suppress the peeling of the reattachment particle peeling preventing film 4 due to the reduction of the strain due to the thermal effect during sputtering. Furthermore, since the surface of the reattachment particle peeling prevention film 4 can be further smoothed, it is possible to more effectively suppress peeling and dropping of the reattachment particles.
[0027]
The constituent material of the reattachment particle peeling prevention film 4 is not particularly limited, and various metal materials (single metal or alloy) or metal compound materials can be used. Considering prevention of peeling due to adhesion and thermal expansion difference, prevention of mixing of other components (contamination) other than forming components into the thin film when the reattachment particle peeling prevention film 4 is sputtered, the target body 1 is It is preferable to apply a metal thin film or metal compound thin film containing a constituent metal element.
[0028]
Specifically, when the thin film formed using the sputtering target 3 is made of a single metal, it is preferable to form the reattachment particle peeling preventing film 4 with the metal thin film itself. Further, when the thin film to be formed is a metal compound, it is preferable that the reattachment particle peeling preventing film 4 is made of a single metal element thin film constituting the metal compound or the metal compound thin film itself. For example, when a metal compound film is formed by reactive sputtering, a metal target is used for the target body 1, and a reattachment particle peeling prevention film 4 made of a metal compound thin film is formed in a non-erosion region of such a metal target. By doing so, it is possible to obtain the stress relaxation effect of the redeposits deposited there, and it is possible to further enhance the effect of suppressing the exfoliation of the redeposits.
[0029]
A metal thin film or metal compound thin film other than the metal element constituting the target body 1 can be applied to the reattachment particle peeling prevention film 4, but in that case, a difference in thermal expansion coefficient from the target body 1. Is 1 × 10^-6It is preferable to select the material so that it is within / K. The difference in thermal expansion coefficient between the reattachment particle peeling prevention film 4 and the target body 1 is 1 × 10^-6If it exceeds / K, the reattachment particle peeling prevention film 4 itself may be peeled off due to thermal stress, and the reattachment may be peeled off easily.
[0030]
Moreover, it is preferable that the film thickness of the reattachment particle peeling prevention film 4 is in the range of 1 to 10 μm. When the film thickness of the reattachment particle peeling prevention film 4 exceeds 10 μm, not only the film itself is easily peeled but also the state of the film surface is deteriorated and the reattachment particles are likely to fall off. On the other hand, when the film thickness of the reattachment particle peeling prevention film 4 is less than 1 μm, there is a possibility that the density enhancement effect and the smoothing effect of the reattachment particles deposited thereon cannot be sufficiently obtained. For the same reason, the surface roughness of the film surface of the reattachment particle peeling prevention film 4 is preferably 1 μm or less in terms of arithmetic average roughness Ra defined in JIS G0601-1994.
[0031]
As described above, in the sputtering target 3 according to the first embodiment, the reattachment particle peeling prevention film 4 is formed as a surface treatment in advance in the non-erosion region of the target body 1. It can be deposited with high density and smoothness under high adhesion strength, and the adhesion strength of the reattachment itself and the adhesion strength with the base (reattachment particle peeling prevention film 4) can be increased. By these, generation | occurrence | production of the dust resulting from peeling of the reattachment thing, and dropping, specifically the fine dust about 0.2 micrometers or less in diameter can be prevented effectively. In particular, it is possible to effectively prevent the generation of dust due to separation and removal of the reattachment even in the latter stage of sputtering (near the target life).
[0032]
Next, a sputtering target according to the second embodiment of the present invention will be described. FIG. 3 is a cross-sectional view showing a schematic structure of the sputtering target according to the second embodiment. A sputtering target 7 shown in FIG. 3 has a structure in which a disk-shaped target body 1 is supported by a backing plate 2, and these configurations are the same as those in the first embodiment described above.
[0033]
Here, as is apparent from the magnetron sputtering apparatus shown in FIG. 2, the reattached particles are attached not only to the non-erosion region of the target body 1 but also to the exposed surface of the backing plate 2. Therefore, in the sputtering target 7 shown in FIG. 3, the reattachment particle peeling preventing film 4 is formed on the exposed surface of the backing plate 2 by the PVD method or the CVD method. The detailed conditions of the reattachment particle peeling preventing film 4 are the same as those in the first embodiment.
[0034]
As described above, by forming the reattachment particle peeling prevention film 4 on the exposed surface of the backing plate 2, the reattachment particles attached thereon can be deposited with high density and smoothness under a high fixing strength. Therefore, the reattachment can be effectively prevented from peeling off and falling off. Therefore, it is possible to prevent the generation of dust due to peeling and dropping of the reattachment.
[0035]
As shown in FIG. 4, the reattachment particle peeling prevention film 4 is formed on the non-erosion region of the target body 1, that is, on the surface center portion, the surface outer peripheral portion and the side surface portion of the target body 1, and the exposed surface of the backing plate 2. It is particularly preferable to do this. As a result, it is possible to more effectively reduce the generation of dust due to peeling and dropping of the reattachment.
[0036]
In the sputtering apparatus of the present invention, the sputtering target (3, 7) of the present invention is applied to a target portion of a sputtering apparatus that has been generally used conventionally as shown in FIG. Although not shown in FIG. 2, the substrate 5 as a film formation sample is held by a holder or the like, and the substrate 5 and the sputtering target 3 are arranged in a vacuum vessel.
[0037]
According to the sputtering targets 3 and 7 of the present invention described above, it is possible to effectively prevent the generation of dust due to itself. Therefore, according to the sputtering apparatus using such a sputtering target, the quality of the sputtered film can be greatly improved. Then, a sputtered film formed using the sputtering target of the present invention, that is, a metal thin film or a metal compound thin film is used for a wiring film, an electrode, an element constituent film, etc. of an electronic component such as a semiconductor element or a liquid crystal display element. As a result, it becomes possible to improve the manufacturing yield of electronic components.
[0038]
【Example】
Next, specific examples of the present invention will be described.
[0039]
Example 1
First, a 5N purity Ti disc serving as a Ti target (target body) and an Al alloy (6061) plate serving as a backing plate were diffusion-bonded by hot pressing. These were machined into the desired target shape and backing plate shape. Specifically, the Ti target had an outer diameter of 250 mm and a thickness of 15 mm. The backing plate had an outer diameter of 300 mm.
[0040]
Next, the Ti target surface was masked so as to cover a portion having an inner diameter of 240 mm. That is, the masking process was performed so that the outer peripheral 5 mm width part and side part of the Ti target surface were exposed. Through this masking, a Ti thin film having a film thickness of about 5 μm was formed as a reattachment particle peeling prevention film on the outer peripheral portion and side portions of the Ti target and further on the exposed surface of the backing plate by CVD. Thus, the Ti sputtering target in which the reattachment particle peeling prevention film was formed by the CVD method was subjected to a film formation test described later.
[0041]
Example 2
Except that a reattachment particle peeling prevention film (Ti thin film having a film thickness of about 5 μm) is formed by sputtering on the outer periphery and side surfaces of the Ti target and on the exposed surface of the backing plate, Ti is the same as in Example 1. A sputtering target was produced. A Ti sputtering target in which this reattached particle peeling preventing film was formed by a sputtering method was subjected to a film formation test described later.
[0042]
Example 3
Example 1 except that a reattachment particle peeling prevention film (Ti thin film with a film thickness of about 3 μm) is formed on the outer peripheral surface and side surfaces of the Ti target and on the exposed surface of the backing plate by the arc ion plating method. Thus, a Ti sputtering target was produced. Here, as a pretreatment for forming the reattachment particle peeling prevention film by the arc ion plating method, the Ti target before film formation is arranged in a vacuum apparatus to be 2.4 × 10.^-3After evacuating to Pa, preheating to 300 ° C., Ar bombard cleaning was performed for 30 minutes, and Ti bombard cleaning was further performed for 10 minutes. Thus, the Ti sputtering target in which the reattachment particle peeling prevention film was formed by the arc ion plating method was subjected to a film formation test described later.
[0043]
Comparative Example 1
A Ti sputtering target was produced in the same manner as in Example 1 except that no treatment was applied to the outer peripheral portion and side portions of the surface of the Ti target and the exposed surface of the backing plate. The Ti sputtering target that had not been subjected to the anti-peeling treatment for the reattached particles was subjected to a film formation test described later.
[0044]
Comparative Example 2
A Ti sputtering target was produced in the same manner as in Example 1 except that only the blasting treatment was performed on the outer peripheral portion and the side surface portion of the Ti target and the exposed surface of the backing plate. A Ti sputtering target to which a blast treatment was applied as a peeling prevention treatment for the reattached particles was subjected to a film formation test described later.
[0045]
Comparative Example 3
A Ti sputtering target was produced in the same manner as in Example 1 except that a Ti thin film having a film thickness of about 5 μm was formed by thermal spraying on the outer peripheral portion and side portions of the surface of the Ti target and on the exposed surface of the backing plate. A Ti sputtering target on which a sprayed film was formed as a delamination preventing process for the reattached particles was subjected to a film formation test described later.
[0046]
Using each Ti sputtering target according to Examples 1 to 3 and Comparative Examples 1 to 3 described above, a sputtering pressure of 4 × 10^{- 1}Pa, sputtering current 5A, Ar flow rate 15sccm, N₂Magnetron sputtering was performed at a flow rate of 30 sccm to form a Ti thin film on a 6-inch Si wafer. Then, after 100 lots, 150 lots, and 200 lots, the number of dusts (number of particles) of 0.2 μm or more on each Ti thin film was measured with a particle counter. The measurement results are shown in Table 1.
[0047]
[Table 1]

[0048]
As is apparent from Table 1, according to the Ti sputtering targets according to Examples 1 to 3, the amount of dust generated is reduced as compared with the Ti sputtering targets of Comparative Examples 1 to 3. In particular, it can be seen that the amount of dust generated near the target life is greatly reduced.
[0049]
Example 4
Aside from forming a reattachment particle peeling prevention film consisting of Ti thin films with thicknesses of 5μm, 20μm, 50μm and 100μm on the outer periphery and side surfaces of the Ti target and the exposed surface of the backing plate, respectively, by the arc ion plating method Respectively produced sputtering targets in the same manner as in Example 3. With respect to these sputtering targets, a film formation test was performed under the same conditions as in Example 3. After 100 lots, 150 lots, and 200 lots, the number of particles (number of particles) of 0.2 μm or more on each Ti thin film was measured. It was measured. The measurement results are shown in Table 2. Table 2 also shows the surface roughness of the reattachment particle peeling prevention film (Ti thin film).
[0050]
[Table 2]

[0051]
As is clear from Table 2, each Ti sputtering target according to Sample 1 of Example 3 and Example 4 produced less dust, whereas according to Samples 2 to 4 of Example 4 in which the thickness of the Ti thin film was increased. Each sputtering target has increased dust generation. This is because in Samples 2 to 4 of Example 4, the surface roughness of the Ti thin film increases as the film thickness increases, so that the reattached particles attached to the shadowed portions of the film surface drop off. Or the reattachment particles are concentrated on the tip of the convex part of the film surface and the film stress is increased, so that the number of dust generation is increased as compared with the sample 1 of Example 3 or Example 4. Conceivable. As can be seen from this result, the film thickness of the reattachment particle peeling prevention film is preferably in the range of 1 to 10 μm.
[0052]
Example 5
Before forming the reattachment particle peeling prevention film, the surface of the Ti target is etched to remove the processed strain layer and clean the surface, and then reattachment particle peeling prevention consisting of a 3μm thick Ti thin film A sputtering target was produced in the same manner as in Example 3 except that the film was formed by the arc ion plating method. With respect to this sputtering target, a film formation test was performed under the same conditions as in Example 3, and the number of dusts of 0.2 μm or more on each Ti thin film after 100 lots, 150 lots, and 200 lots was measured. The measurement results are shown in Table 3. Table 3 also shows the surface roughness of the reattachment particle peeling prevention film (Ti thin film).
[0053]
[Table 3]

[0054]
As is clear from Table 3, the amount of dust generated in the sputtering target of Example 5 is slightly lower than that of the sputtering target of Example 3. As can be seen from this, it is preferable that the formation surface (surface of the target body) of the reattachment particle peeling prevention film is a clean surface from which the processing strain layer and the like have been removed in advance.
[0055]
Example 6
Prepare a Ti target (sample 1) with a mirror-finished surface and a Ti target (sample 2) with a mirror-finished and etched surface, and reattach the Ti thin film with a thickness of 3 μm on the outer periphery and side of the surface. A sputtering target was produced in the same manner as in Example 3 except that the particle separation preventing film was formed by the arc ion plating method. With respect to these sputtering targets, a film formation test was performed under the same conditions as in Example 3, and the number of dusts of 0.2 μm or more on each Ti thin film after 100 lots, 150 lots, and 200 lots was measured. Table 4 shows the measurement results. Table 4 also shows the surface roughness of the reattachment particle peeling prevention film (Ti thin film).
[0056]
[Table 4]

[0057]
As is apparent from Table 4, the amount of dust generated in each sputtering target of Example 6 is slightly lower than that of the sputtering target of Example 3. As can be seen from this, it is preferable that the surface on which the reattachment particle peeling prevention film is formed (the surface of the target body) is a smooth surface.
[0058]
Example 7
First, a 5N purity Ta disk serving as a Ta target (target body) and an Al alloy (6061) sheet serving as a backing plate were diffusion bonded by hot pressing. These were machined into the desired target shape and backing plate shape. Specifically, the Ta target had an outer diameter of 250 mm and a thickness of 15 mm. The backing plate had an outer diameter of 300 mm.
[0059]
Next, the surface of the Ta target was masked so as to cover a portion having an inner diameter of 240 mm. That is, the masking process was performed so that the outer peripheral 5 mm width portion and the side surface portion of the Ta target surface were exposed. Through this masking, a Ta thin film having a thickness of about 5 μm was formed as a reattachment particle peeling prevention film on the outer peripheral portion and side portions of the Ta target and further on the exposed surface of the backing plate by CVD. Thus, the Ta sputtering target in which the reattachment particle peeling prevention film was formed by the CVD method was subjected to a film formation test described later.
[0060]
Example 8
Except for forming a reattachment particle peeling prevention film (Ta thin film having a film thickness of about 5 μm) on the outer peripheral and side surfaces of the Ta target and the exposed surface of the backing plate by the sputtering method, Ta A sputtering target was produced. A Ta sputtering target in which this reattached particle peeling preventing film was formed by a sputtering method was subjected to a film formation test described later.
[0061]
Example 9
Example 7 except that a reattachment particle peeling prevention film (Ta thin film with a film thickness of about 3 μm) is formed on the outer peripheral surface and side surfaces of the Ta target and the exposed surface of the backing plate by the arc ion plating method. Thus, a Ta sputtering target was produced. Here, as a pretreatment for forming the reattachment particle peeling prevention film by the arc ion plating method, the Ta target before film formation is arranged in a vacuum apparatus to be 2.4 × 10.^-3After evacuating to Pa, preheating to 300 ° C., Ar bombard cleaning was performed for 30 minutes, and Ta bombard cleaning was further performed for 10 minutes. Thus, the Ta sputtering target in which the reattachment particle peeling prevention film was formed by the arc ion plating method was subjected to a film formation test described later.
[0062]
Comparative Example 4
A Ta sputtering target was prepared in the same manner as in Example 7 except that no treatment was performed on the outer peripheral portion and side surface portion of the Ta target and the exposed surface of the backing plate. The Ta sputtering target not subjected to the peeling prevention treatment for the reattached particles was subjected to a film formation test described later.
[0063]
Comparative Example 5
A Ta sputtering target was produced in the same manner as in Example 7 except that only the blasting treatment was performed on the outer peripheral portion and side surface portion of the Ta target and the exposed surface of the backing plate. The Ta sputtering target subjected to the blast treatment as the anti-peeling treatment for the reattached particles was subjected to a film formation test described later.
[0064]
Comparative Example 6
A Ta sputtering target was prepared in the same manner as in Example 7 except that a Ta thin film having a film thickness of about 5 μm was formed by thermal spraying on the outer peripheral surface and side surfaces of the Ta target and on the exposed surface of the backing plate. The Ta sputtering target on which a sprayed film was formed as a process for preventing the reattachment particles from peeling was subjected to a film formation test described later.
[0065]
Using each Ta sputtering target according to Examples 7 to 9 and Comparative Examples 4 to 6 described above, a sputtering pressure of 4 × 10^{- 1}Pa, sputtering current 5A, Ar flow rate 5sccm, N₂Magnetron sputtering was performed at a flow rate of 3 sccm to form a TaN thin film on a 6-inch Si wafer. The number of dust (particles) of 0.2 μm or more on each TaN thin film after 100 lots, 150 lots, and 200 lots was measured with a particle counter. Table 5 shows the measurement results.
[0066]
[Table 5]

[0067]
As is clear from Table 5, according to the Ta sputtering targets according to Examples 7 to 9, the amount of dust generated is reduced as compared with the Ta sputtering targets of Comparative Examples 4 to 6. In particular, it can be seen that the amount of dust generated near the target life is greatly reduced.
[0068]
Example 10
Other than forming a reattachment particle peeling prevention film made of Ta thin film with a film thickness of 5μm, 20μm, 50μm, and 100μm on the outer periphery and side surface of Ta target and the exposed surface of backing plate, respectively, by arc ion plating method Respectively produced sputtering targets in the same manner as in Example 9. With respect to these sputtering targets, a film formation test was performed under the same conditions as in Example 9. After 100 lots, 150 lots, and 200 lots, the number of dusts (number of particles) of 0.2 μm or more on each TaN film was measured. It was measured. Table 6 shows the measurement results. Table 6 also shows the surface roughness of the reattachment particle peeling prevention film (Ta thin film).
[0069]
[Table 6]

[0070]
Example 11
Before the reattachment particle peeling prevention film is formed, etching treatment is performed on the surface of the Ta target to remove the processed strain layer and clean the surface, and then reattachment particle peeling prevention consisting of a 3 μm thick Ta thin film is prevented. A sputtering target was produced in the same manner as in Example 9 except that the film was formed by the arc ion plating method. With respect to this sputtering target, a film formation test was performed under the same conditions as in Example 9, and the number of dusts of 0.2 μm or more on each TaN film after 100 lots, 150 lots, and 200 lots was measured. The measurement results are shown in Table 7. Table 7 also shows the surface roughness of the reattachment particle peeling prevention film (Ta thin film).
[0071]
[Table 7]

[0072]
Example 12
Prepare a Ta target (sample 1) with a mirror-finished surface and a Ta target (sample 2) with a mirror-finished and etched surface, and reattach the Ta thin film with a thickness of 3μm on the outer periphery and side of the surface. A sputtering target was produced in the same manner as in Example 9 except that the particle separation preventing film was formed by the arc ion plating method. For these sputtering targets, a film formation test was performed under the same conditions as in Example 9, and the number of dusts of 0.2 μm or more on each TaN film after 100 lots, 150 lots, and 200 lots was measured. Table 8 shows the measurement results. Table 8 also shows the surface roughness of the reattachment particle peeling prevention film (Ta thin film).
[0073]
[Table 8]

[0074]
【The invention's effect】
As described above, according to the sputtering target of the present invention, it is possible to effectively suppress the separation and removal of the reattachment from itself, so that the generation of dust due to the separation and removal of the reattachment is greatly reduced. Can be reduced. Therefore, it is possible to provide a high-quality sputtered film with good reproducibility.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a schematic configuration of a sputtering target according to a first embodiment of the present invention.
FIG. 2 is a diagram schematically showing a configuration of a general magnetron sputtering apparatus.
FIG. 3 is a cross-sectional view showing a schematic configuration of a sputtering target according to a second embodiment of the present invention.
4 is a cross-sectional view showing a modification of the sputtering target shown in FIG.
[Explanation of symbols]
1 …… Target body
2 ... Backing plate
3, 7 ... Sputtering target
4. Reattachment particle peeling prevention film

Claims (12)

A sputtering target comprising a target body and a reattachment particle peeling prevention film formed on at least a part of a non-erosion region of the target body and formed by a PVD method or a CVD method,
A sputtering target, wherein the reattachment particle peeling prevention film has a film thickness of 3 to 10 μm and the film surface has an arithmetic average roughness Ra of 1 μm or less. The sputtering target according to claim 1, wherein
The sputtering target according to claim 1, wherein the target body is supported by a backing plate. A sputtering target comprising: a target body; a backing plate that supports the target body; and a reattachment particle peeling prevention film that is provided on at least a part of the surface of the backing plate and is formed by a PVD method or a CVD method. And
A sputtering target, wherein the reattachment particle peeling prevention film has a film thickness of 3 to 10 μm and the film surface has an arithmetic average roughness Ra of 1 μm or less. In the sputtering target according to claim 3,
Furthermore, the said reattachment particle | grain peeling prevention film is formed in at least one part of the non-erosion area | region of the said target main body, The sputtering target characterized by the above-mentioned. In the sputtering target according to any one of claims 1 to 4,
The said reattachment particle | grain peeling prevention film consists of a metal thin film or metal compound thin film formed by sputtering method, an ion plating method, or CVD method, The sputtering target characterized by the above-mentioned. The sputtering target according to any one of claims 1 to 5,
The said reattachment particle | grain peeling prevention film consists of a metal thin film or metal compound thin film containing the metal element which comprises the said target main body, The sputtering target characterized by the above-mentioned. In the sputtering target according to any one of claims 1 to 6,
The target body is made of a metal element selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Pt, Ag, Ir, Ru, Fe, Ni, Co, Al, Cu, Si and Ge. A sputtering target comprising a single element or an alloy or compound containing the metal element. In a sputtering apparatus comprising: a vacuum container; a film formation sample holding unit disposed in the vacuum container; and a target unit disposed in the vacuum container so as to face the film formation sample holding unit.
The said target part has a sputtering target of any one of Claim 1 thru | or 7, The sputtering device characterized by the above-mentioned. A method for producing a sputtering target, comprising: a target body; and a reattachment particle peeling prevention film provided by at least a part of a non-erosion region of the target body and formed by a PVD method or a CVD method,
A step of performing at least one treatment selected from bombard cleaning, mirror finishing, and etching on the portion of the target body where the reattachment particle peeling prevention film is formed;
Forming the reattachment particle peeling prevention film having a film thickness of 3 to 10 μm and a surface roughness of the film surface having an arithmetic average roughness Ra of 1 μm or less in the treated portion. A method for producing a sputtering target. Production of a sputtering target comprising a target body, a backing plate for supporting the target body, and a reattachment particle peeling prevention film provided on at least a part of the surface of the backing plate and formed by a PVD method or a CVD method A method,
Performing at least one kind of treatment selected from bombard cleaning, mirror finishing, and etching on the portion of the backing plate where the reattachment particle peeling prevention film is formed;
Forming the reattachment particle peeling prevention film having a film thickness of 3 to 10 μm and a surface roughness of the film surface having an arithmetic average roughness Ra of 1 μm or less in the treated portion. A method for producing a sputtering target.   A method for producing a thin film, comprising a step of forming a thin film using the sputtering target according to any one of claims 1 to 7.   A method for manufacturing an electronic component, comprising a step of forming a thin film using the sputtering target according to claim 1.

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