CN100593230C - 用于等离子体反应器室的无o形环串列节流阀 - Google Patents

用于等离子体反应器室的无o形环串列节流阀 Download PDF

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CN100593230C
CN100593230C CN200680014181A CN200680014181A CN100593230C CN 100593230 C CN100593230 C CN 100593230C CN 200680014181 A CN200680014181 A CN 200680014181A CN 200680014181 A CN200680014181 A CN 200680014181A CN 100593230 C CN100593230 C CN 100593230C
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塙广二
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16KVALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K1/00Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces
    • F16K1/32Details
    • F16K1/52Means for additional adjustment of the rate of flow
    • F16K1/526Means for additional adjustment of the rate of flow for limiting the maximum flow rate, using a second valve
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16KVALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K1/00Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces
    • F16K1/16Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces with pivoted closure-members
    • F16K1/18Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces with pivoted closure-members with pivoted discs or flaps
    • F16K1/22Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces with pivoted closure-members with pivoted discs or flaps with axis of rotation crossing the valve member, e.g. butterfly valves
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16KVALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K1/00Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces
    • F16K1/16Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces with pivoted closure-members
    • F16K1/18Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces with pivoted closure-members with pivoted discs or flaps
    • F16K1/22Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces with pivoted closure-members with pivoted discs or flaps with axis of rotation crossing the valve member, e.g. butterfly valves
    • F16K1/223Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces with pivoted closure-members with pivoted discs or flaps with axis of rotation crossing the valve member, e.g. butterfly valves with a plurality of valve members
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32Gas-filled discharge tubes
    • H01J37/32431Constructional details of the reactor
    • H01J37/3244Gas supply means
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32Gas-filled discharge tubes
    • H01J37/32431Constructional details of the reactor
    • H01J37/3244Gas supply means
    • H01J37/32449Gas control, e.g. control of the gas flow
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00Fluid handling
    • Y10T137/8593Systems
    • Y10T137/87265Dividing into parallel flow paths with recombining
    • Y10T137/87523Rotary valve
    • Y10T137/87531Butterfly valve

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  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Plasma & Fusion (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Fluid Mechanics (AREA)
  • Plasma Technology (AREA)
  • Drying Of Semiconductors (AREA)
  • Lift Valve (AREA)
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Abstract

一种阀系统,具有高的最大气体导通性和对气体导通性的精密控制,所述阀系统包括:阀壳体,用于阻挡经过气体流路的气流;穿过所述壳体的大面积开口,具有第一弓形侧壁;穿过所述壳体的小面积开口,具有第二弓形侧壁;以及大面积和小面积可旋转阀翼片,分别位于所述大面积开口和小面积开口中并具有分别与所第一和第二弓形侧壁一致的弓形边缘,并在其间分别限定了第一阀间隙和第二阀间隙。第一阀间隙和第二阀间隙小到足以阻挡高达预定压力限制的所述阀壳体一侧的气流,从而消除了对O形环的任何需要。

Description

用于等离子体反应器室的无O形环串列节流阀
技术领域
本发明涉及用于等离子体反应器室的无O形环串列节流阀。
背景技术
半导体电路制造所用的大多数等离子体处理需要用耦合到等离子体反应器室的真空泵将等离子体反应器室维持在亚大气压的压力下。通常,真空泵以额定恒定的速率工作,同时用耦合在室与真空泵之间的蝶形阀来调节室压力。蝶形阀具有可旋转的盘状翼片(flap),所述盘状翼片的旋转位置决定了真空泵的流率并因而控制了室压力。阀翼片通常在其周围具有O形环,在阀处于关闭位置的任何时候,O形环都处于阀壳体的边缘。为了确保当阀翼片处于关闭位置时的密封性,O形环是必须的。在使O形环处于略微开启的位置以达到期望的室压力时,O形环会受到磨损。经O形环流过的等离子体和气体与O形环的材料发生反应并使之变差或除去。因此,必须周期形地维护阀并更换O形环,这需要很大的维护费用并使反应器有很长的停工期。
另一个问题是,在阀的最大流动能力及其精确调节室压力的能力之间存在某种折衷。可以对压力进行控制的分辨率大体上与阀的直径成反比。这是因为,取决于用来使翼片旋转的电动机或伺服装置,对阀翼片的旋转角度的控制被限制在最小的角度行程。最小角度行程或分辨率可以是小于1度。对于很小直径的阀翼片和开口而言,这种分辨率可以对室压力实现高精度或精密控制。但是,对于较大直径的阀翼片或开口,翼片移过这种最小角度行程就会造成室压力相当大的改变,从而不能对室压力进行精密控制。这种问题可以通过采用较小直径的阀翼片和开口来克服。但是,这种措施限制了将室排空或对其清洁时所能采用的流率。例如,采用小直径的阀不能通过NF3气体用清洁气体和副产品的快速“倾泻”来对室进行清洁。
需要一种压力控制阀,它具有很高的流率(最大开口尺寸),但是尽管最大开口尺寸较大,也仍然能以像很小的阀那样的精确度对室压力进行控制,这种阀不需要对O形环进行周期形的更换。
发明内容
一种阀系统,具有高的最大气体流率和对气体流率的精密控制,所述阀系统包括:阀壳体,用于阻挡气体流经气体流路;穿过所述壳体并具有第一弓形侧壁的大面积开口;穿过所述壳体并具有第二弓形侧壁的小面积开口;以及大面积和小面积可旋转阀翼片,分别位于所述大面积开口和小面积开口中并具有分别与所第一和第二弓形侧壁一致的弓形边缘,并在其间分别限定了第一阀间隙和第二阀间隙。第一阀间隙和第二阀间隙小到足以阻挡预定最小气流极限的预定压力极限通过所述阀壳体的气流,从而消除了对O形环的任何需要。
附图说明
图1A图示了包括本发明的阀组件的一种等离子体反应器。
图1B是图1A的阀组件中阀的放大剖视侧视图。
图2是图1B的阀中阀翼片顶侧的立体图。
图3是图2的阀翼片底侧的立体图。
图4是阀组件的剖视侧视图。
图5是图4的阀组件中阀翼片和壳体的立体图。
图6是阀组件的剖视末端图。
图7是图1的反应器中阀系统的立体图,包括驱动电动机和反馈控制系统。
具体实施方式
参考图1A和图1B,等离子体反应器10具有包围了真空室16的顶板12和侧壁14,晶片支撑底座18位于室16内用于支撑待处理的硅晶片。处理气体供应器11通过气体喷射装置13将处理气体或处理气体混合物供应到室16中。从RF偏压功率发生器15通过阻抗匹配电路17向晶片底座18施加等离子体偏压功率。可以从RF源功率发生器19并通过阻抗匹配电路21向源功率施加器(source power applicator,例如可以是天线或电极,并可以位于顶板12处或底座18处)23施加等离子体源功率。泵送环20限定在侧壁14与底座18之间。泵送导管22耦合在泵送环20与外部真空泵24之间。
泵送导管22的内表面具有对阀壳体28进行支撑的肩部26,阀壳体28横跨泵送导管22的整个直径延伸。阀壳体28支撑了一对串列蝶形阀,即较大的高容量阀30和较小的精密控制阀32。高容量阀30由穿过阀壳体28的圆形开口34以及可旋转的阀翼片36组成。阀翼片36是扁平的一部分球体,因此具有弓形边缘38。穿过阀壳体28的开口34的边缘40具有与阀翼片弓形边缘38匹配的类似弓形形状。在翼片36处于关闭位置(即与阀壳体28的平面平行)时,弓形边缘38、40限定了具有厚度T的弓形间隙。弓形间隙的半径足够小,使得不存在经过弓形间隙从阀内侧到外侧(即从室16到泵24)的直线路径。这有助于限制气体经弓形间隙逸出的速率。优选地,弓形间隙的厚度T小于给定压力范围内室16中气体或等离子体的平均碰撞自由程。在一种实施例中,这个压力范围可以是2mT至200mT。换句话说,该实施例中的间隙厚度足够小,以致比高达200mT的室压力下的平均碰撞自由程更小。取决于期望的室压力工作范围,间隙厚度T可以在例如约0.010到0.030英寸之间,或者更小。对室压力的粗控制是通过对高容量阀翼片36的旋转位置进行控制来获得的,所述位置确定了阀开口的尺寸d(图1B)。通过这种小间隙以及经过间隙的环形路径,处理气体或等离子体产物经过间隙逸出的速率较低。这种特征消除了对用任何O形环来密封间隙的需要,是一个显著的优点。
高容量阀30的导通性情况是由阀开口尺寸d来确定的,该尺寸与阀翼片36的角度位置或旋转位置有单调关系(对于0度(关闭)直至90度(完全开启)的角度位置范围)。这种导通性情况以及气体流率决定了室压力,因此通过阀翼片36的旋转来控制阀开口尺寸d,从而对室进行调节。
精密控制阀32由穿过阀壳体28的圆形开口44和可旋转的阀翼片46组成。阀翼片46是扁平的一部分球体,因此具有弓形边缘48。穿过阀壳体28的开口44的边缘50具有与阀翼片弓形边缘48匹配的类似弓形形状。在翼片46处于关闭位置(即与阀壳体28的平面平行)时,弓形边缘48、60限定了具有厚度t的弓形间隙51。弓形间隙51的半径足够小,使得不存在经过弓形间隙51从阀内侧到外侧(即从室16到泵24)的直线路径。这有助于限制气体经弓形间隙51逸出的速率。
根据有助于防止气体经间隙51逸出的另一个特征,间隙厚度t小于给定压力范围内室16中气体或等离子体的平均碰撞自由程。在一种实施例中,这个压力范围可以是2mT至200mT。换句话说,该实施例中的间隙厚度足够小,以致比高达200mT的室压力下的平均碰撞自由程更小。间隙厚度可以是例如约0.010至0.030英寸。对室压力的精密控制是通过对翼片46的旋转位置进行控制来获得的,所述位置确定了阀开口的尺寸。通过这种小间隙以及经过间隙的环形路径,处理气体或等离子体产物经过间隙逸出的速率较低。这种特征消除了对用任何O形环来密封间隙的需要,是一个显著的优点。
经过阀32的导通性情况是由阀开口尺寸来确定的,该尺寸与阀翼片46的角度位置或旋转位置有单调关系(对于0度(关闭)直至90度(完全开启)的角度位置范围)。各个串列阀30、32单独的导通性情况的并行总和与气体流率决定了室压力,因此通过阀翼片36和46的旋转来控制各个阀30、32的阀开口尺寸,从而对室压力进行调节。高容量阀30的一个优点是,通过将高容量阀30的翼片36旋转到其完全开启(即相对于阀壳体28的平面垂直)的角度位置,可以获得特别大的室排空率。高容量阀的直径可以很大(例如9英寸),从而实现用清洁气体(例如NF3)或用例如膜沉积期间的沉积气体进行室清洁操作的过程中所需大的室排空速率。但是,高容量阀不提供将室压力调节至期望压力值的最精确调节,因为其翼片36的较小角度旋转即可给室压力产生较大改变。精确控制是由精密控制阀32来提供的,其开口直径可以小至1英寸(例如)。在精密控制阀32的情况下,其翼片46的较小角度旋转给室压力产生较小的改变,从而便于对室压力进行较小的精确调节。此外,由于其直径较小,精密控制阀翼片46具有较小的惯性矩,这使得用具有适度扭矩能力的电动机即可对室压力实现非常迅速的校正或改变,从而增强了阀32的精密控制能力。
在工作中,高容量阀30被设定到旋转位置(即开口尺寸d),该位置将室压力设定成比所需室压力高出某个差值,所述差值小到足以处于精密控制阀32的补偿能力范围之内。然后通过开启精密控制阀32直至室压力已降低到期望值为止,来将室压力精确地调节到精确的期望压力值。由于精密控制阀32具有这样小的开度,所以精密控制阀翼片46的旋转运动对室压力实施了很小的改变,从而便于对室压力进行精确调节。
图2示出了阀翼片36面向室16的一个表面(“等离子体”侧)是光滑的连续表面。图3的立体图示出了阀翼片36的相反那侧由周围的裙部60部分地包围的中空状空间,裙部60限定了弓形边缘38并从平坦顶表面62轴向延伸。经过翼片的中心而在裙部60的相反侧之间延伸的径向支柱64提供了刚度。轮轴或轴66部分地跨越直径并经过裙部60的一侧延伸。轴66覆盖并紧固到径向支柱64之一上。与轴66对准的销61从裙部60的相反侧向外径向延伸。参考图4的剖视图,顶部环70套在壳体28上半部分的中空环72中。顶部环70形成了弓形边缘40的上半部分,而壳体28形成了弓形边缘40的另外半部分。在顶部环70被以螺栓方式固定到位时,阀壳体28中形成的半圆柱形轴孔28a以及顶部环70中形成的匹配半圆柱形轴孔28b形成包围了轴66的圆柱形轴孔27。半圆柱形轴衬套71覆盖了轴66中延伸到顶部环70之外的部分。以类似方式,在顶部环70被以螺栓方式固定到位时,阀壳体28中形成的半圆柱形销孔29a以及顶部环70中的匹配半圆柱形销孔29b形成包围了轴66的圆柱形销孔29。一对聚四氟乙烯衬垫74a、74b分别包围轴66和销61,并保持翼片36在阀开口34内的轴向位置。对于约0.010至0.030英寸量级的间隙厚度,聚四氟乙烯衬垫74a、74b各自具有例如约0.010英寸的厚度。
较小的精密控制阀32和翼片46是与较大的粗控制阀30和翼片36相同但较小的形式,因此具有与图2、图3和图4所示相同的结构,但尺寸更小。例如,在一种实施例中,精密控制阀32约为粗控制阀30直径的约1/10。
一种可选的特征是,如图5和图6所示,通过在阀开口34的弓形表面40中形成增强流动的槽90,来增大高容量阀30中的导通性情况。槽90可以是弓形的,其径向槽深度s在阀壳体28的表面处具有最大深度,并在壳体28表面下方的某个深度p处为零,槽深度s随着壳体表面下方的深度而减小。在壳体28表面下方的选定深度p处,槽深度s达到零(使得槽90消失)。类似的槽91可以从壳体28的相反表面延伸,并以与槽90相同的方式沿相反方向变细。上下槽90、91对准并可以具有相同的深度p。它们的共同槽深度p小于阀壳体28厚度的一半,从而在两个槽90、91之间存在弯曲开口表面40的表面区域40a。如图6所示,结果是当阀翼片36处于关闭(平行)位置时,阀翼片36的周边与表面区域40a之间存在期望厚度T的间隙。如本说明书中此前所述,间隙厚度T足够小,从而在不需要O形环的情况下限制气体或等离子体经过阀的泄漏速率。
槽90、91的目的是使经过阀的导通性情况随着翼片从其关闭位置的旋转而增大的速率增加。这种增加是通过上部壳体表面中的槽90和下部壳体表面中的槽91的数目增加而增大的。
图7图示了怎样用一对快速正耦合器电动机(positive coupler motor)93、95来控制各个阀翼片36、46的旋转。电动机93、95分别耦合到阀30、32的轴。反馈控制系统97把从室内压力传感器98接收到的实际室压力测量结果与期望室压力进行比较,并通过电动机93、95来控制两个阀30、32的位置。可以对控制系统97编程以通过对电动机93进行操作而使实际室压力与期望值大致匹配,然后通过对电动机95进行操作而实现实际室压力与期望室压力的精确匹配。
面向等离子体反应器的阀壳体表面和阀翼片表面优选为与等离子体处理相容的材料。对于某些处理,该材料可以是铝。阀壳体和阀翼片面向真空泵的相反那侧以及轴可以由其他材料(例如钢或不锈钢)形成。不需要O形环来密封阀组件,这是一个显著的优点。
尽管已经参考优选实施例对本发明进行了详细说明,但是应当明白,在不脱离本发明的真正精神和范围的情况下,可以对其进行各种变更和修改。

Claims (18)

1.一种阀系统,具有高的最大气体导通性和对气体导通性的精密控制,所述阀系统包括:
阀壳体,用于限制经过气体流路的气流;
穿过所述壳体的大面积开口,具有第一弓形侧壁;
大面积可旋转阀翼片,位于所述大面积开口中,并具有与所第一弓形侧壁一致的弓形边缘,并在其间限定了第一阀间隙;
穿过所述壳体的小面积开口,具有第二弓形侧壁;和
小面积可旋转翼片,处于所述小面积开口中,并具有与所述第二弓形侧壁一致的弓形边缘,并在其间限定了第二阀间隙。
2.根据权利要求1所述的阀系统,其中,所述第一阀间隙小到足以将高达预定压力极限的所述阀壳体的气体导通性限制在预定气体流率。
3.根据权利要求1所述的阀系统,其中,所述第一阀间隙和所述第二阀间隙小到足以将高达预定压力极限的所述阀壳体的气体导通性限制在预定最小气体流率。
4.根据权利要求3所述的阀系统,其中,所述预定压力极限为200mT,其中,所述最小气体流率为10sccm。
5.根据权利要求2所述的阀系统,其中,所述第一阀间隙小于所述预定压力极限内所述气体的平均碰撞自由程长度。
6.根据权利要求3所述的阀系统,其中,所述第一阀间隙和所述第二阀间隙小于所述预定压力极限内所述气体的平均碰撞自由程长度。
7.根据权利要求1所述的阀系统,还包括:
所述大面积开口的所述侧壁内的多个槽。
8.根据权利要求7所述的阀系统,其中,所述多个槽包括所述侧壁内的弓形孔,所述弓形孔从所述阀壳体的一个表面延伸并具有深度,所述深度在所述侧壁的一个表面处最大,并在所述阀壳体的所述一个表面下方的预定距离处减小到最小值或零深度。
9.根据权利要求8所述的阀系统,还包括多个槽,所述多个槽从所述阀壳体的相反表面延伸并在所述侧壁中包括弓形孔,所述弓形孔具有深度,所述深度在所述侧壁的所述相反表面处最大,并在所述相反表面下方的预定距离处减小到最小值或零深度。
10.根据权利要求9所述的阀系统,其中,从所述一个表面延伸的所述多个槽以及从所述相反表面延伸的所述多个槽被所述侧壁的无槽区域分隔开。
11.一种阀组件,用于控制从等离子体反应器室向真空泵的气体导通性或室压力中的一者,所述阀组件包括:
阀壳体,具有相反的第一和第二表面;
高导通阀,包括:
大面积开口,处于相反的所述第一和第二表面中并穿过所述阀壳体延伸,所述开口限定了在所述第一表面与所述第二表面之间延伸并具有弓形截面的侧壁,
大面积可旋转翼片,处于所述大面积开口中并具有周边边缘,所述周边边缘具有与所述侧壁的弓形截面匹配的弓形截面,在处于关闭翼片位置时,所述周边边缘与所述侧壁之间限定了小间隙;
精密控制阀,包括:
小面积开口,处于相反的所述第一和第二表面中并穿过所述阀壳体延伸,所述开口限定了在所述第一表面与所述第二表面之间延伸并具有弓形截面的侧壁,
小面积可旋转翼片,处于所述小面积开口中并具有周边边缘,所述周边边缘具有与所述侧壁的弓形截面匹配的弓形截面,在处于关闭翼片位置时,所述周边边缘与所述侧壁之间限定了小间隙。
12.根据权利要求11所述的阀组件,其中,每个所述小间隙小到足以将预定压力范围内经过所述阀组件的气体导通性限制在预定最小气体流率。
13.根据权利要求12所述的阀组件,其中,所述压力范围延伸到高达200mT,其中,所述最小气体流率为10sccm。
14.根据权利要求11所述的阀组件,其中,每个所述小间隙在千分之二十英寸的量级。
15.根据权利要求11所述的阀组件,其中,在所述反应器室的选定压力范围内,每个所述间隙小于所述反应器室中等离子体的平均碰撞自由程长度。
16.根据权利要求11所述的阀组件,还包括:
所述大面积开口的所述侧壁中的多个槽。
17.根据权利要求16所述的阀组件,其中,所述多个槽包括所述侧壁内的弓形孔,所述弓形孔从所述阀壳体的一个表面延伸并具有深度,所述深度在所述侧壁的一个表面处最大,并在所述阀壳体的所述一个表面下方的预定距离处减小到最小值或零深度。
18.根据权利要求17所述的阀组件,还包括多个槽,所述多个槽从所述阀壳体的相反表面延伸并在所述侧壁中包括弓形孔,所述弓形孔具有深度,所述深度在所述侧壁的所述相反表面处最大,并在所述相反表面下方的预定距离处减小到最小值或零深度。
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JP2008539596A (ja) 2008-11-13
US7428915B2 (en) 2008-09-30
KR20080002825A (ko) 2008-01-04
WO2006116511A3 (en) 2007-09-27
WO2006116511A2 (en) 2006-11-02
JP4875697B2 (ja) 2012-02-15
US20060237136A1 (en) 2006-10-26

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