本発明によれば、ターゲット上に複数のピークが現出しかつ内周側のピーク値が外周側のピーク値よりも大であるような磁界分布（半径方向の漏洩磁場の水平成分）が得られるので、ターゲットのエロージョン領域が拡大されるマグネトロンスパッタリング装置を実現することができる。特に本発明によれば、小口径（直径が２００ｍｍ以下）の磁性ターゲットに適用した場合にも、より内周側にターゲットを飽和させ得るだけのピーク値をもった漏洩磁場を容易に発生できるので、ターゲットのエロージョン領域が拡大されることにより、基板上に均一な膜厚分布を有する薄膜を形成することができる。
According to the present invention, a magnetic field distribution (a horizontal component of a leakage magnetic field in the radial direction) in which a plurality of peaks appear on the target and the inner peripheral peak value is larger than the outer peripheral peak value is obtained. Therefore, it is possible to realize a magnetron sputtering apparatus in which the erosion region of the target is enlarged. In particular, according to the present invention, even when applied to a magnetic target having a small diameter (diameter of 200 mm or less), it is possible to easily generate a leakage magnetic field having a peak value that can saturate the target on the inner peripheral side. By expanding the erosion region of the target, a thin film having a uniform film thickness distribution can be formed on the substrate.
以下本発明の詳細を添付図面により説明する。図１は本発明の実施の形態に係わる磁石ユニットの平面図、図２は図１のＡ−Ａ線断面図、図３は図２をＢ方向からみた矢視図、図４は図１の磁石ユニットの漏洩磁場分布を示す図、図５はターゲット表面Ｙ軸上での漏洩磁場水平成分の分布を示す図、図６は従来の磁石ユニットの漏洩磁場分布を示す図である。
Details of the present invention will be described below with reference to the accompanying drawings. Figure 1 is a plan view of a magnet unit according to an embodiment of the present invention, FIG. 2 is a sectional view along line A-A of FIG. 1, FIG. 3 arrow view of the FIG. 2 from direction B, Fig. 4 in FIG. 1 FIG. 5 is a diagram showing a leakage magnetic field distribution of a magnet unit, FIG. 5 is a diagram showing a distribution of a leakage magnetic field horizontal component on the target surface Y axis, and FIG. 6 is a diagram showing a leakage magnetic field distribution of a conventional magnet unit.
図１〜３において、１はマグネトロンスパッタリング用磁石ユニットであり、３／４円周（円弧角２７０°）を占める円弧状の主磁石部材２と、１／４円周（円弧角９０°）を占める円弧状の副磁石部材３と、これらの表面に保持された強磁性体からなる円板状のヨーク４と、これらの外周を取り囲む非磁性体からなる円筒状のベース５と、副磁石部材３の外周に装着された非磁性体からなる円弧状のバランスウエイト６と、ヨーク４の表面に締結部材（例えばボルト）８で固定されたスペーサ７とを有する。主磁石部材２は、軸方向に磁化した複数の台形状の第１永久磁石片２１ａを円弧状に配置した第１磁石体２１と、半径方向に磁化した複数の台形状の第２永久磁石片２２ａを円弧状に配置して形成した第２磁石体２２と、軸方向に磁化した複数の台形状の第３永久磁石片２３ａを円弧状に配置して形成した第３磁石体２３と、半径方向に磁化した複数の台形状の第４永久磁石片２４ａを円弧状に配置して形成した第４磁石体２４と、軸方向に磁化した複数の台形状の第５永久磁石片２５ａを円弧状に配置した第５磁石体２５を内周から外周に向って配置した磁石組立体である。この主磁石部材２では、各永久磁石片はその円弧角は３０°に形成され、円周方向に９個接続することにより、円弧角（θ１）が２７０°に形成された第１〜第５磁石体２１〜２５が形成され、各磁石体は同心円状に配置されている。
1 to 3, reference numeral 1 denotes a magnetron sputtering magnet unit having an arc-shaped main magnet member 2 occupying a 3/4 circumference (arc angle 270 °) and a 1/4 circumference (arc angle 90 °). Occupied arcuate submagnet member 3, disk-shaped yoke 4 made of a ferromagnetic material held on the surfaces thereof, cylindrical base 5 made of a nonmagnetic material surrounding the outer periphery thereof, and submagnet member 3 has an arc-shaped balance weight 6 made of a non-magnetic material mounted on the outer periphery of 3 , and a spacer 7 fixed to the surface of the yoke 4 with a fastening member (for example, a bolt) 8. The main magnet member 2 includes a first magnet body 21 in which a plurality of trapezoidal first permanent magnet pieces 21a magnetized in the axial direction are arranged in an arc shape, and a plurality of trapezoidal second permanent magnet pieces magnetized in the radial direction. A second magnet body 22 formed by arranging 22a in an arc, a third magnet body 23 formed by arranging a plurality of trapezoidal third permanent magnet pieces 23a magnetized in the axial direction, and a radius A fourth magnet body 24 formed by arranging a plurality of trapezoidal fourth permanent magnet pieces 24a magnetized in the direction in an arc shape, and a plurality of trapezoidal fifth permanent magnet pieces 25a magnetized in the axial direction in an arc shape This is a magnet assembly in which the fifth magnet body 25 arranged in the above is arranged from the inner periphery toward the outer periphery. In the main magnet member 2, each permanent magnet piece has an arc angle of 30 °, and by connecting nine pieces in the circumferential direction, the arc angle (θ 1 ) is formed to be 270 °. Five magnet bodies 21 to 25 are formed, and each magnet body is arranged concentrically.
副磁石部材３は、軸方向に磁化した複数の台形状の第６永久磁石片３１ａを円弧状に配置した第６磁石体３１と、半径方向に磁化した複数の台形状の第７永久磁石片３２ａを円弧状に配置して形成した第７磁石体３２と、軸方向に磁化した複数の台形状の第８永久磁石片３３ａを円弧状に配置して形成した第８磁石体３３と、半径方向に磁化した複数の台形状の第９永久磁石片３４ａを円弧状に配置して形成した第９磁石体３４と、軸方向に磁化した複数の台形状の第１０永久磁石片３５ａを円弧状に配置した第１０磁石体３５を内周から外周に向って同心円上に配置した磁石組立体である。この副磁石部材３では、各永久磁石片はその円弧角度は３０°に形成され、円周方向に３個接続することにより、円弧角度（θ２）が９０°に形成された第６〜第１０磁石体３１〜３５が形成されている。このように主磁石部材２及び副磁石部材３は、いずれも軸方向に磁化した３重の円弧状の磁石体と各磁石体の間に各々配置された半径方向に磁化された円弧状磁石体とを組合せることにより形成されている。但し、副磁石部材３は、全体として主磁石部材２よりも中心軸Ｃに近づいて配置され、これにより、第６磁石体３１の両側面は第１磁石体２１の一部と接し、第７磁石体３２の両側面は第１磁石体２１と第２磁石体２２に接し、第８磁石体３３の両側面は第２磁石体２２と接し、第９磁石体３４の両側面は第３、４磁石体２３、２４と接し、第１０磁石体３５の両側面は第４磁石体２４の両側面と接するように構成されている。
The sub magnet member 3 includes a sixth magnet body 31 in which a plurality of trapezoidal sixth permanent magnet pieces 31a magnetized in the axial direction are arranged in an arc shape, and a plurality of trapezoidal seventh permanent magnet pieces magnetized in the radial direction. A seventh magnet body 32 formed by arranging 32a in an arc shape, an eighth magnet body 33 formed by arranging a plurality of trapezoidal eighth permanent magnet pieces 33a magnetized in the axial direction, and a radius; A plurality of trapezoidal ninth permanent magnet pieces 34a magnetized in the direction are arranged in an arc shape, and a plurality of trapezoidal tenth permanent magnet pieces 35a magnetized in the axial direction are arcuately formed. 10 is a magnet assembly in which the tenth magnet body 35 arranged concentrically is arranged concentrically from the inner periphery toward the outer periphery. In this secondary magnet member 3, each permanent magnet piece has an arc angle of 30 °, and by connecting three pieces in the circumferential direction, the arc angle (θ 2 ) is formed at 90 °. Ten magnet bodies 31 to 35 are formed. As described above, the main magnet member 2 and the sub magnet member 3 are each a triple arc-shaped magnet body magnetized in the axial direction and a radially magnetized arc-shaped magnet body arranged between the magnet bodies. Are combined. However, the sub-magnet member 3 is disposed closer to the central axis C than the main magnet member 2 as a whole, whereby both side surfaces of the sixth magnet body 31 are in contact with part of the first magnet body 21 , Both side surfaces of the magnet body 32 are in contact with the first magnet body 21 and the second magnet body 22, both side surfaces of the eighth magnet body 33 are in contact with the second magnet body 22, and both side surfaces of the ninth magnet body 34 are third, The four magnet bodies 23 and 24 are in contact with each other, and both side surfaces of the tenth magnet body 35 are in contact with both side surfaces of the fourth magnet body 24 .
上記の磁石ユニット１において、磁性ターゲット表面（Ｙ軸上）に発生する半径方向の漏洩磁場の水平成分をシミュレーションで算出した結果を図５に示す。図５に示す磁束密度分布は、各永久磁石片として１８ｍｍの厚さを有するＮｄ−Ｆｅ−Ｂ系焼結磁石（日立金属社製ＨＳ５０ＡＨ）を使用し、外径が１３８ｍｍの磁石ユニットを組立て、磁石表面から軸方向に所定距離Ｌ（＝１５ｍｍ）(図２参照)だけ離間した位置における漏洩磁束密度の水平成分の測定値である。図５から、主磁石部材２では、図中実線で示すように外周側に第１のピーク値が現出し、内周側に第１のピーク値よりも大なる第２のピーク値が現出するような磁束密度分布が得られ、また副磁石部材３でも、図中破線で示すように外周側に第１のピーク値が現出し、内周側に第１のピーク値よりも大なる第２のピーク値が現出するような磁束密度分布が得られることがわかる。両ピーク値は、ターゲット材の材質やその飽和磁化の値に応じて最適な数値が定まるが、一般に、第２のピーク値は第１のピーク値よりも５％以上高いことが好ましい。但し本発明は、磁性ターゲットが極めて小さい（例えば外径１５０ｍｍ未満である）場合は、内周側にターゲットを飽和させ得るピーク磁場を発生することが困難なので、特に外径が１５０ｍｍ以上、２００ｍｍ以下の磁性ターゲットを使用したマグネトロンスパッタリング装置に組み込むことが望ましい。
FIG. 5 shows the result of calculating the horizontal component of the radial leakage magnetic field generated on the magnetic target surface (on the Y axis) by simulation in the magnet unit 1. The magnetic flux density distribution shown in FIG. 5 uses an Nd—Fe—B based sintered magnet (HS50AH manufactured by Hitachi Metals) having a thickness of 18 mm as each permanent magnet piece, and assembles a magnet unit having an outer diameter of 138 mm. This is a measured value of the horizontal component of the leakage magnetic flux density at a position separated from the magnet surface by a predetermined distance L (= 15 mm) (see FIG. 2) in the axial direction. From FIG. 5, in the main magnet member 2, the first peak value appears on the outer peripheral side and the second peak value larger than the first peak value appears on the inner peripheral side as shown by the solid line in the figure. In the secondary magnet member 3, the first peak value appears on the outer peripheral side as shown by the broken line in the figure, and the first peak value is larger than the first peak value on the inner peripheral side. It can be seen that a magnetic flux density distribution in which a peak value of 2 appears is obtained. Both peak values are determined in accordance with the material of the target material and the saturation magnetization value. In general, the second peak value is preferably 5% or more higher than the first peak value. However, in the present invention, when the magnetic target is extremely small (for example, the outer diameter is less than 150 mm), it is difficult to generate a peak magnetic field that can saturate the target on the inner peripheral side. It is desirable to incorporate in a magnetron sputtering apparatus using a magnetic target.
１：マグネトロンスパッタリング用磁石ユニット、２：主磁石部材、３：副磁石部材、
４：ヨーク、５：ベース、６：バランスウエイト、７：スペーサ、８：締結部材
２１：第１磁石体、２１ａ：第１永久磁石片、２２：第２磁石体、
２２ａ：第２永久磁石片、２３：第３磁石体、２３ａ：第３永久磁石片、
２４：第４磁石体、２４ａ：第４永久磁石片、２５：第５磁石体、
２５ａ：第５永久磁石片、３１：第６磁石体、３１ａ：第６永久磁石片、
３２：第７磁石体、３２ａ：第７永久磁石片、３３：第８磁石体、
３３ａ：第８永久磁石片、３４：第９磁石体、３４ａ：第９永久磁石片、
３５：第１０磁石体、３５ａ：第１０永久磁石片
1: Magnet unit for magnetron sputtering, 2: Main magnet member, 3: Sub magnet member,
4: yoke, 5: base, 6: balance weight, 7: spacer, 8: fastening member 21: first magnet body, 21a: first permanent magnet piece, 22: second magnet body,
22a: second permanent magnet piece, 23: third magnet body , 23a: third permanent magnet piece,
24: 4th magnet body , 24a: 4th permanent magnet piece , 25: 5th magnet body,
25a: fifth permanent magnet piece, 31: sixth magnet body, 31a: sixth permanent magnet piece,
32: seventh magnet body, 32a: seventh permanent magnet piece, 33: eighth magnet body,
33a: eighth permanent magnet piece, 34: ninth magnet body, 34a: ninth permanent magnet piece,
35: 10th magnet body, 35a: 10th permanent magnet piece
