CN111557040A - Partially anodized printhead - Google Patents

Abstract

Embodiments disclosed herein generally relate to an apparatus having a partially anodized gas distribution showerhead including a body having a plurality of gas passages extending through the body from an upstream side to a downstream side, the body having a central region and a peripheral region having an anodization layer disposed on the upstream side and the downstream side.

Description

Translated fromChinese

部分阳极化的喷头Partially anodized printhead

技术领域technical field

本文所公开的实施方式总体涉及具有部分阳极化的气体分配喷头的设备。Embodiments disclosed herein generally relate to apparatus having partially anodized gas distribution showerheads.

背景技术Background technique

等离子体增强化学气相沉积(PECVD)一般用于在基板(诸如半导体基板，太阳能面板基板、平板显示器(FPD)基板、有机发光显示器(OLED)基板等)上沉积薄膜。PECVD一般通过将处理气体从气体分配喷头引入真空腔室中而实现，该真空腔室具有设置在基座上的基板。通过从耦接到腔室的一个或多个RF源向腔室中的电极施加RF电流，处理气体被激发成等离子体。等离子体进行反应以在定位在基座上的基板的表面上形成材料层。气体分配喷头的设计、以及RF电流的施加对等离子体的性质有很大影响。Plasma-enhanced chemical vapor deposition (PECVD) is generally used to deposit thin films on substrates such as semiconductor substrates, solar panel substrates, flat panel display (FPD) substrates, organic light emitting display (OLED) substrates, and the like. PECVD is generally accomplished by introducing process gases from a gas distribution showerhead into a vacuum chamber having a substrate disposed on a susceptor. The process gas is excited into a plasma by applying RF current to electrodes in the chamber from one or more RF sources coupled to the chamber. The plasma reacts to form a layer of material on the surface of the substrate positioned on the susceptor. The design of the gas distribution showerhead, as well as the application of RF current, has a large effect on the properties of the plasma.

在工业中利用的基板中的一些是平坦介质，诸如典型地用于制造平板显示器、太阳能器件、OLED器件以及其他应用的玻璃、塑料或其他材料的矩形、柔性片材。在平坦介质上形成电子器件、膜以及其他结构的材料通过众多工艺(包括PECVD)沉积到平坦介质上。然而，等离子体密度，特别是在平坦介质的周边处的等离子体密度，一般与平坦介质的周边的内侧的等离子体密度不同。等离子体密度的这种不均匀性造成跨越平坦介质的区域的膜厚度的不均匀性。已经对气体分配喷头和/或PECVD工艺参数进行了众多修改，但是还未消除膜均匀性的变化量。Some of the substrates utilized in the industry are flat media, such as rectangular, flexible sheets of glass, plastic or other materials typically used in the manufacture of flat panel displays, solar devices, OLED devices, and other applications. Materials that form electronic devices, films, and other structures on flat dielectrics are deposited onto flat dielectrics by a number of processes, including PECVD. However, the plasma density, especially at the perimeter of the flat medium, is generally different from the plasma density inside the perimeter of the flat medium. This non-uniformity in plasma density creates non-uniformity in film thickness across regions of the flat medium. Numerous modifications have been made to the gas distribution showerhead and/or PECVD process parameters, but the amount of variation in film uniformity has not been eliminated.

因此，本领域中需要具有减轻或最小化上述不均匀性的气体分配喷头的设备。Accordingly, there is a need in the art for an apparatus having a gas distribution showerhead that mitigates or minimizes the aforementioned non-uniformities.

发明内容SUMMARY OF THE INVENTION

本文所公开的实施方式总体涉及具有部分阳极化的气体分配喷头的设备。在一个实施方式中，提供了一种气体分配喷头，所述气体分配喷头包括主体，所述主体具有从上游侧穿过所述主体延伸到下游侧的多个气体通道，所述主体具有中心区域和周边区域，所述周边区域具有设置在所述上游侧和所述下游侧上的阳极化层。Embodiments disclosed herein generally relate to apparatus having partially anodized gas distribution showerheads. In one embodiment, a gas distribution showerhead is provided that includes a body having a plurality of gas passages extending through the body from an upstream side to a downstream side, the body having a central region and a peripheral region having an anodized layer disposed on the upstream side and the downstream side.

在另一个实施方式中，公开了一种等离子体处理设备。所述设备包括：处理腔室主体，所述处理腔室主体具有壁和底板；基座，所述基座设置在所述处理腔室主体中，并在第一位置与第二位置之间是可移动的；以及一个或多个条带，所述一个或多个条带耦接到所述基座，并耦接到所述底板或所述壁中的一个或多个。所述设备包括喷头，所述喷头设置在所述处理腔室主体中并与所述基座相对，并且具有延伸穿过所述喷头的一个或多个气体通道。所述喷头包括主体，所述主体具有从上游侧穿过所述主体延伸到下游侧的多个气体通道，所述主体具有中心区域和周边区域，所述周边区域具有设置在所述上游侧和所述下游侧上的阳极化层。In another embodiment, a plasma processing apparatus is disclosed. The apparatus includes: a processing chamber body having a wall and a floor; a pedestal disposed in the processing chamber body between a first position and a second position removable; and one or more straps coupled to the base and to one or more of the floor or the wall. The apparatus includes a showerhead disposed in the processing chamber body opposite the susceptor and having one or more gas passages extending through the showerhead. The showerhead includes a main body having a plurality of gas passages extending through the main body from an upstream side to a downstream side, the main body having a central region and a peripheral region having disposed on the upstream side and a peripheral region. the anodized layer on the downstream side.

在另一个实施方式中，公开了一种等离子体增强化学气相沉积设备。所述设备包括：腔室主体，所述腔室主体具有多个壁和腔室底板；以及基座，所述基座设置在所述腔室主体中并在第一位置和第二位置之间是可移动的，所述第一位置与所述腔室底板间隔开第一距离，所述第二位置与所述腔室底板间隔开大于所述第一距离的第二距离。所述设备还包括多个条带，所述多个条带耦接到所述基座，并耦接到腔室底板和多个壁中的一个或多个。所述多个条带沿所述基座不均匀地分布。所述设备还包括气体分配喷头，所述气体分配喷头设置在所述腔室主体中并与所述基座相对，所述喷头具有延伸穿过所述喷头的多个气体通道并具有中心部分和边缘部分。所述气体分配喷头包括主体，所述主体具有从上游侧穿过所述主体延伸到下游侧的多个气体通道，所述主体具有中心区域和周边区域，所述周边区域具有设置在所述上游侧和所述下游侧上的阳极化层。In another embodiment, a plasma enhanced chemical vapor deposition apparatus is disclosed. The apparatus includes: a chamber body having a plurality of walls and a chamber floor; and a base disposed in the chamber body between a first position and a second position is movable, the first position is spaced a first distance from the chamber floor, and the second position is spaced a second distance greater than the first distance from the chamber floor. The apparatus also includes a plurality of straps coupled to the base and to one or more of a chamber floor and a plurality of walls. The plurality of strips are unevenly distributed along the base. The apparatus also includes a gas distribution showerhead disposed in the chamber body opposite the base, the showerhead having a plurality of gas passages extending through the showerhead and having a central portion and edge part. The gas distribution showerhead includes a main body having a plurality of gas passages extending through the main body from an upstream side to a downstream side, the main body having a central region and a peripheral region having a peripheral region disposed on the upstream side anodized layer on the side and the downstream side.

附图说明Description of drawings

为了能够详细地理解本公开内容的上述特征的方式，可参考实施方式来获得上文简要地概述的本公开内容的更特定的描述，其中一些实施方式在附图中例示。然而，应注意，附图仅例示了本公开内容的典型实施方式，并因此不应视为对本公开内容的范围的限制，因为本公开内容可允许其他等效实施方式。In order that the manner in which the above-described features of the present disclosure can be understood in detail, a more specific description of the present disclosure, briefly summarized above, may be obtained by reference to the embodiments, some of which are illustrated in the accompanying drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equivalent embodiments.

图1是根据一个实施方式的设备的示意性截面图。Figure 1 is a schematic cross-sectional view of an apparatus according to one embodiment.

图2是喷头的一个实施方式的平面图。Figure 2 is a plan view of one embodiment of a showerhead.

图3是根据另一个实施方式的喷头的示意性截面图。3 is a schematic cross-sectional view of a showerhead according to another embodiment.

图4是根据一个实施方式的气体分配喷头相对于处理腔室壁的示意性截面图。4 is a schematic cross-sectional view of a gas distribution showerhead relative to a processing chamber wall, according to one embodiment.

为了便于理解，已经尽可能地使用相同的附图标记标示各附图共有的相同元件。设想的是，一个实施方式中公开的要素可有益地用于其他实施方式，而无需赘述。To facilitate understanding, where possible, the same reference numerals have been used to designate the same elements common to the various figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized in other embodiments without elaboration.

具体实施方式Detailed ways

本文所公开的实施方式总体涉及具有部分阳极化的气体分配喷头的设备。气体分配喷头由铝制成，并且一些部分保持为裸铝(bare aluminum)，而其他部分则如本文所公开那样被阳极化。在气体分配喷头的周边区域处提供阳极化，而在周边区域内的部分保持为裸铝。气体分配喷头会影响等离子体的性质，从而减少跨越基板的膜厚度的不均匀性。Embodiments disclosed herein generally relate to apparatus having partially anodized gas distribution showerheads. The gas distribution showerhead is made of aluminum, and some portions remain bare aluminum, while other portions are anodized as disclosed herein. Anodization is provided at the peripheral area of the gas distribution showerhead, while the portion within the peripheral area remains bare aluminum. The gas distribution showerhead affects the properties of the plasma, thereby reducing non-uniformity in film thickness across the substrate.

本文所讨论的实施方式将参考由作为美国加利福尼亚州圣克拉拉市应用材料公司的子公司AKT公司(AKT America,a subsidiary of Applied Materials,Inc.,SantaClara,CA)制造和销售的大面积PECVD腔室。应理解，本文所讨论的实施方式也可在其他腔室中实践，包括由其他制造商出售的腔室。大面积处理腔室的尺寸被设定为处理平坦介质，诸如具有大于约一万五千平方厘米的面积的平坦、柔性基板。在一个实施方式中，基板可具有大于约五万平方厘米的面积。在另一个实施方式中，基板可具有大于约五万五千平方厘米的面积。在另一个实施方式中，基板可具有大于约六万平方厘米的面积。在另一个实施方式中，基板可具有大于约九万平方厘米的面积。Embodiments discussed herein will refer to large area PECVD chambers manufactured and sold by AKT America, a subsidiary of Applied Materials, Inc., Santa Clara, CA, USA room. It should be understood that the embodiments discussed herein may also be practiced in other chambers, including chambers sold by other manufacturers. Large area processing chambers are sized to process flat media, such as flat, flexible substrates having an area greater than about fifteen thousand square centimeters. In one embodiment, the substrate may have an area greater than about fifty thousand square centimeters. In another embodiment, the substrate may have an area greater than about fifty-five thousand square centimeters. In another embodiment, the substrate may have an area greater than about sixty thousand square centimeters. In another embodiment, the substrate may have an area greater than about ninety thousand square centimeters.

图1是根据一个实施方式的设备100的示意性截面图。在所示出的实施方式中，设备100是PECVD设备。设备100包括腔室主体102，来自气源104的处理气体被馈送到该腔室主体102中。当设备100用于沉积时，处理气体从气源被馈送通过远程等离子体源106并通过管108。在远程等离子体源106中，处理气体未点燃成等离子体。在清洁期间，清洁气体从气源104发送到远程等离子体源106，并在来自等离子体的自由基进入腔室之前，清洁气体在远程等离子体源106被点燃成等离子体。管108是导电管108。Figure 1 is a schematic cross-sectional view of anapparatus 100 according to one embodiment. In the embodiment shown, theapparatus 100 is a PECVD apparatus. Theapparatus 100 includes achamber body 102 into which process gas from agas source 104 is fed. When theapparatus 100 is used for deposition, the process gas is fed from the gas source through theremote plasma source 106 and through thetube 108 . In theremote plasma source 106, the process gas is not ignited into a plasma. During cleaning, the cleaning gas is sent from thegas source 104 to theremote plasma source 106 where it is ignited into a plasma before radicals from the plasma enter the chamber. Tube 108 isconductive tube 108 .

用于在腔室内将处理气体点燃成等离子体的RF电流从RF源110耦接到管108。由于RF电流的“趋肤效应(skin effect)”，RF电流沿管108的外部行进。RF电流将仅穿透特定、可预定的深度进入导电材料。因此，RF电流沿管108的外部行进，而处理气体在管108的内部行进。当处理气体在管108中行进时，处理气体永远不会“遇到”RF电流，因为RF电流没有足够深入地穿透到管108中，以使处理气体在管108内暴露于RF电流。The RF current used to ignite the process gas into a plasma within the chamber is coupled fromRF source 110 totube 108 . The RF current travels along the exterior of thetube 108 due to the "skin effect" of the RF current. The RF current will only penetrate a specific, predeterminable depth into the conductive material. Therefore, the RF current travels along the outside of thetube 108 while the process gas travels inside thetube 108 . As the process gas travels in thetube 108, the process gas never "encounters" the RF current because the RF current does not penetrate deep enough into thetube 108 to expose the process gas to the RF current within thetube 108.

处理气体通过背板114被馈送到腔室。然后，处理气体膨胀到在背板114与喷头116之间的容积118中。然后，处理气体行进通过多个气体通道156并进入处理容积148中。气体通道156形成为从喷头116的上游侧或背面159至喷头116的下游侧或前面160。Process gases are fed to the chamber through thebacking plate 114 . The process gas then expands into thevolume 118 between thebacking plate 114 and theshowerhead 116 . The process gas then travels through the plurality ofgas channels 156 and into theprocess volume 148 . Thegas passage 156 is formed from the upstream side or backside 159 of theshowerhead 116 to the downstream side orfront side 160 of theshowerhead 116 .

另一方面，RF电流不进入背板114与喷头116之间的容积118。而是，RF电流沿管108的外部行进到背板114。然后，RF电流沿背板114的大气侧158行进。背板114包括导电材料。在一个实施方式中，背板114包括铝。在另一个实施方式中，背板114可包括不锈钢。然后，RF电流从背板沿包括导电材料的支架120行进。在一个实施方式中，支架120包括铝。在另一个实施方式中，支架120包括不锈钢。然后，RF电流沿喷头116的前面160行进，在此处，RF电流在喷头116与基板124之间的处理容积148中将穿过气体通道156的处理气体点燃成等离子体。RF电流行进到达喷头116的前面160的路径由箭头“A”示出。O形环122将壁146与背板114电隔离。On the other hand, RF current does not enter thevolume 118 between thebackplate 114 and theshowerhead 116 . Rather, the RF current travels along the exterior of thetube 108 to thebackplate 114 . The RF current then travels along theatmospheric side 158 of thebackplane 114 . Thebackplane 114 includes a conductive material. In one embodiment, thebacking plate 114 includes aluminum. In another embodiment, thebacking plate 114 may comprise stainless steel. The RF current then travels from the backplane along thesupport 120 comprising conductive material. In one embodiment, thebracket 120 includes aluminum. In another embodiment, thebracket 120 comprises stainless steel. The RF current then travels along thefront face 160 of theshowerhead 116 where it ignites the process gas passing through thegas channel 156 into a plasma in theprocess volume 148 between theshowerhead 116 and thesubstrate 124 . The path that the RF current travels to reach thefront face 160 of theshowerhead 116 is shown by arrow "A". O-ring 122 electrically isolateswall 146 from backingplate 114 .

在一个实施方式中，喷头116可包括导电材料。在另一个实施方式中，喷头116包括金属。在另一个实施方式中，喷头116包括铝。在另一个实施方式中，喷头116包括不锈钢。In one embodiment, theshowerhead 116 may include a conductive material. In another embodiment, theshowerhead 116 includes metal. In another embodiment, theshowerhead 116 includes aluminum. In another embodiment, theshowerhead 116 comprises stainless steel.

由于等离子体，材料(诸如氮化硅(SiN))被沉积到基板124上。在图1所示出的实施方式中，基板124设置在基座126上，该基座能够在第一位置与第二位置之间移动，该第一位置与喷头116间隔开第一距离，该第二位置与喷头116间隔开第二距离，其中第二距离比第一距离小。在图1所示出的实施方式中，基座126设置在杆136上并能够通过致动器140移动。Due to the plasma, material, such as silicon nitride (SiN), is deposited onto thesubstrate 124 . In the embodiment shown in FIG. 1 , thesubstrate 124 is disposed on a base 126 that is movable between a first position and a second position, the first position being spaced apart from theshowerhead 116 by a first distance, which is The second location is spaced apart from theshowerhead 116 by a second distance, wherein the second distance is less than the first distance. In the embodiment shown in FIG. 1 , thebase 126 is provided on therod 136 and is movable by theactuator 140 .

基板124是大面积基板，并且因此，当在升降杆130、132上升高时，该基板可弯曲。因此，升降杆130、132可具有不同长度。当基板124通过狭缝阀开口144插入腔室中时，基座126可处于降低位置。当基座126处于降低位置时，升降杆130、132在基座126上方延伸。因此，基板124首先被放置在升降杆上。升降杆130、132具有不同长度。外升降杆130比内升降杆132长，使得基板124被放置在升降杆130、132上时在中心凹陷。升高基座126以与基板124相遇。基板124以从中心接触基座进展到边缘接触基座的方式与基座126接触，从而排出存在于基座126与基板124之间的任何气体。然后，升降杆130、132与基座124一起被基座126升高。Thebase plate 124 is a large area base plate and, therefore, can bend when raised on the lift bars 130, 132. Thus, thelift rods 130, 132 may have different lengths. The base 126 may be in a lowered position when thesubstrate 124 is inserted into the chamber through theslit valve opening 144 . The lift bars 130, 132 extend above the base 126 when thebase 126 is in the lowered position. Therefore, thebase plate 124 is first placed on the lift rod. Thelift rods 130, 132 have different lengths. The outer lift bars 130 are longer than the inner lift bars 132 so that thebase plate 124 is recessed in the center when placed on the lift bars 130 , 132 . Thebase 126 is raised to meet thebase plate 124 . Thesubstrate 124 contacts thesusceptor 126 in a manner progressing from the center-contacting susceptor to the edge-contacting susceptor, thereby venting any gas present between the susceptor 126 and thesubstrate 124 . Thelift rods 130 , 132 are then raised by the base 126 together with thebase 124 .

当基座126升高到狭缝阀开口144上方时，基座126遇到阴影框架128。阴影框架128在不使用时搁置在狭缝阀开口144上方的突出部142上。由于尺寸的原因，阴影框架128可能无法正确地对准。因此，在阴影框架128或基座126上可存在辊，以允许阴影框架128在基座126上滚动以便适当地对准。阴影框架128用于双重目的。阴影框架128使基座126的未被基板124覆盖的区域免受沉积的影响。另外，当阴影框架128包括电绝缘材料时，将沿基座126行进的RF电流与沿壁146行进的RF电流电屏蔽。在一个实施方式中，阴影框架128包括绝缘材料。在另一个实施方式中，阴影框架128包括陶瓷材料。在另一个实施方式中，阴影框架128包括Al₂O₃。在另一个实施方式中，阴影框架包括在其上具有阳极化层的金属。在一个实施方式中，金属包括铝。在另一个实施方式中，阳极化层包括Al₂O₃。When thepedestal 126 is raised above theslit valve opening 144 , thepedestal 126 encounters theshadow frame 128 . Theshadow frame 128 rests on theprotrusion 142 above theslit valve opening 144 when not in use. Due to size, theshadow frame 128 may not be properly aligned. Accordingly, there may be rollers onshadow frame 128 orbase 126 to allowshadow frame 128 to roll overbase 126 for proper alignment.Shadow frame 128 serves a dual purpose. Theshadow frame 128 shields the areas of thepedestal 126 not covered by thesubstrate 124 from deposition. Additionally, whenshadow frame 128 includes an electrically insulating material, RF current traveling alongbase 126 is electrically shielded from RF current traveling alongwall 146 . In one embodiment, theshadow frame 128 includes an insulating material. In another embodiment, theshadow frame 128 includes a ceramic material. In another embodiment, theshadow frame 128 includes Al₂ O₃ . In another embodiment, the shadow frame includes metal having an anodized layer thereon. In one embodiment, the metal includes aluminum. In another embodiment, the anodized layer includes Al₂ O₃ .

RF电流需要返回到驱动RF电流的电源110。RF电流通过等离子体耦接到基座126。在一个实施方式中，基座126包括诸如铝的导电材料。在另一个实施方式中，基座126包括诸如不锈钢的导电材料。RF电流通过由箭头“B”所示出的路径行进而回到电源110。RF电流在到达电源110之前沿壁146和盖112返回。The RF current needs to be returned to thepower supply 110 driving the RF current. The RF current is coupled to thesusceptor 126 through the plasma. In one embodiment, thebase 126 includes a conductive material such as aluminum. In another embodiment, thebase 126 includes a conductive material such as stainless steel. The RF current travels back to thepower supply 110 through the path shown by arrow "B". The RF current returns alongwall 146 and cover 112 before reachingpower supply 110 .

为了缩短RF电流返回路径，在一个实施方式中，一个或多个条带134耦接到基座126。通过利用条带134，RF电流将沿条带134向下行进到腔室的底部138并然后返回到腔室的内壁146。在没有条带134的情况下，RF电流将沿基座126的底部行进，顺着杆136向下行进，然后沿腔室的底部138和内壁146返回。沿基座126的底部行进的RF电流与腔室的杆136或底部138上的RF电流之间可能存在高电势差。由于电势不同，在基座下方的容积150中可能发生电弧放电。条带134减小了在容积150中发生电弧放电的可能性。To shorten the RF current return path, in one embodiment, one ormore straps 134 are coupled to thebase 126 . By utilizing thestrip 134, the RF current will travel down thestrip 134 to thebottom 138 of the chamber and then back to theinner wall 146 of the chamber. Without thestrips 134, the RF current would travel along the bottom of thebase 126, down therods 136, and return along the bottom 138 andinner walls 146 of the chamber. There may be a high potential difference between the RF current traveling along the bottom of thepedestal 126 and the RF current on thestem 136 orbottom 138 of the chamber. Due to the difference in potential, arcing may occur in thevolume 150 below the susceptor. Thestrips 134 reduce the likelihood of arcing in thevolume 150 .

在另一个实施方式中，在喷头116的一部分上提供阳极化层170。在一些实施方式中，基座126不仅具有耦接到基座126的条带134，而且具有通过耦接到基座126的底部的延伸部174而实现的RF返回元件172。RF返回元件172耦接到当基座126处于降低位置时支撑阴影框架128的突出部142。图1所示出的RF返回元件172是在基座126与突出部142之间提供电连接的棒。RF返回元件172提供的返回路径比条带134短，并且因此，大部分RF电流将通过RF返回元件172而不是通过条带134返回到RF电源。其他RF返回元件也可与阳极化层170和条带134结合使用，这将在下文讨论。在一个实施方式中，RF返回元件172可设置在突出部142上并在其下方延伸，直到来自基座126的延伸部174移动到与RF返回元件172接触。In another embodiment, theanodized layer 170 is provided on a portion of theshowerhead 116 . In some embodiments, thebase 126 has not only thestrap 134 coupled to thebase 126 , but also theRF return element 172 implemented by theextension 174 coupled to the bottom of thebase 126 . TheRF return element 172 is coupled to theprotrusion 142 that supports theshadow frame 128 when thebase 126 is in the lowered position. TheRF return element 172 shown in FIG. 1 is a rod that provides an electrical connection between the base 126 and theprotrusion 142 . The return path provided by theRF return element 172 is shorter than that of thestrip 134 and, therefore, most of the RF current will return to the RF power supply through theRF return element 172 rather than through thestrip 134 . Other RF return elements may also be used in conjunction with theanodized layer 170 and strips 134, which will be discussed below. In one embodiment, theRF return element 172 may be disposed on and extend below theprotrusion 142 until theextension 174 from the base 126 moves into contact with theRF return element 172 .

阳极化层170可用于调谐处理容积148内的等离子体。如下文更详细地描述的，喷头116包括中心区域和围绕中心区域的边缘或周边区域，并且在周边区域上提供阳极化层170，而中心区域保持为裸铝。短语“裸铝”被定义为无涂层的表面，而铝表面上常见的天然或原生氧化物层除外。阳极化层170可被定义为与天然存在的层(诸如原生氧化物层)相反的故意设置在表面上的层或涂层。阳极化层170可以是比天然存在的氧化物层厚的氧化物层。可基于以下两个相互竞争的关注点的平衡来确定喷头116的被阳极化层170覆盖的表面区域：颗粒产生(影响产量)和等离子体均匀性(影响膜均匀性)。Anodized layer 170 may be used to tune the plasma withinprocess volume 148 . As described in more detail below, theshowerhead 116 includes a central region and an edge or peripheral region surrounding the central region, and ananodized layer 170 is provided on the peripheral region, while the central region remains bare aluminum. The phrase "bare aluminum" is defined as an uncoated surface, other than the natural or native oxide layer commonly found on aluminum surfaces.Anodized layer 170 may be defined as a layer or coating that is intentionally placed on a surface as opposed to a naturally occurring layer, such as a native oxide layer. Theanodized layer 170 may be a thicker oxide layer than the naturally occurring oxide layer. The surface area of theshowerhead 116 covered by the anodizedlayer 170 may be determined based on a balance of two competing concerns: particle generation (affecting yield) and plasma uniformity (affecting film uniformity).

图2是喷头200的一个实施方式的平面图。喷头200可在设备100中用作喷头116。喷头200包括由铝(诸如铝合金)制成的主体205。主体205包括形成在背面159(如图1所示)与前面160之间的多个气体通道156。FIG. 2 is a plan view of one embodiment of ashowerhead 200 .Showerhead 200 may be used inapparatus 100 asshowerhead 116 .Showerhead 200 includes abody 205 made of aluminum, such as an aluminum alloy. Thebody 205 includes a plurality ofgas passages 156 formed between the rear face 159 (shown in FIG. 1 ) and thefront face 160 .

喷头200的主体205由虚线分开以指示喷头200的边缘或周边区域210和中心区域215。中心区域215被周边区域210包围。中心区域215是裸铝，而周边区域210被阳极化(例如，包括图1所示出的阳极化层170)。中心区域215和周边区域210对施加到其上的RF能量有不同反应。通过提供阳极化层170，基座126(如图1所示)与喷头200之间的等离子体密度在对应于中心区域215和周边区域210的位置处不同。Thebody 205 of theshowerhead 200 is separated by a dashed line to indicate an edge orperipheral region 210 and acentral region 215 of theshowerhead 200 . Thecentral area 215 is surrounded by theperipheral area 210 . Thecentral region 215 is bare aluminum, while theperipheral region 210 is anodized (eg, including the anodizedlayer 170 shown in FIG. 1 ). Thecentral region 215 and theperipheral region 210 respond differently to RF energy applied thereto. By providinganodized layer 170 , the plasma density between susceptor 126 (shown in FIG. 1 ) andshowerhead 200 differs at locations corresponding tocentral region 215 andperipheral region 210 .

分别与次要侧边230和主要侧边235相距的距离220和距离225可不同或相同。距离220和距离225可基于基座126(在图1中示出)与喷头200之间的期望的等离子体特性。距离220和距离225可描述为第一表面区域240和第二表面区域245，第一表面区域240被阳极化而第二表面区域245是裸铝。第一表面区域240和第二表面区域245可以由表面区域百分比或比率(例如，裸铝与阳极化涂层的百分比或比率)表示。在一些实施方式中，第一表面区域240(涂覆区域)相对于第二表面区域245(未涂覆区域)的百分比为约20％至约25％。Thedistances 220 and 225 from thesecondary side 230 and theprimary side 235, respectively, may be different or the same.Distance 220 anddistance 225 may be based on desired plasma characteristics between susceptor 126 (shown in FIG. 1 ) andshowerhead 200 .Distance 220 anddistance 225 can be described as afirst surface area 240 and asecond surface area 245, thefirst surface area 240 being anodized and thesecond surface area 245 being bare aluminum. Thefirst surface area 240 and thesecond surface area 245 may be represented by surface area percentages or ratios (eg, bare aluminum to anodized coating percentages or ratios). In some embodiments, the percentage of the first surface area 240 (coated area) relative to the second surface area 245 (uncoated area) is about 20% to about 25%.

可基于在基座126(如图1所示)与喷头200之间提供的期望的等离子体密度来选择第一表面区域240(阳极化区域)相对于第二表面区域245(裸铝区域)的大小。例如，第一表面区域240的尺寸可选择为减小在基座126与喷头200之间的区域处的等离子体密度(作为电容效应)。通过提供阳极化周边区域210来减小喷头200的周边区域210处的等离子体密度可导致在基板的周边区域处的膜厚度减小。然而，相对于裸铝，阳极化涂层的多孔性更高。虽然孔隙率增加了颗粒保留，但是存在一些颗粒可能脱落并污染形成在基板上的膜的可能性。另外，阳极化涂层具有与裸铝不同的性质。这些性质包括硬度、热膨胀系数等。性质上的差异可能导致阳极化涂层的微小开裂和/或剥离并产生颗粒污染。因此，本领域的技术人员可在竞争的膜均匀性和颗粒问题之间取得平衡，以达到相对于裸铝的最佳阳极化面积。如本文所述的喷头200能够最小化作为气流效应的颗粒污染的风险。喷头200还通过控制沉积膜纯度来优化装置设计规则。具有阳极化周边区域210和裸露中心区域215的喷头200提供期望的等离子体密度以及管理膜沉积均匀性。The ratio of the first surface area 240 (anodized area) relative to the second surface area 245 (bare aluminum area) may be selected based on the desired plasma density provided between the susceptor 126 (shown in FIG. 1 ) and theshowerhead 200 . size. For example, the dimensions of thefirst surface area 240 may be selected to reduce the plasma density (as a capacitive effect) at the area between the susceptor 126 and theshowerhead 200 . Reducing the plasma density at theperipheral region 210 of theshowerhead 200 by providing an anodizedperipheral region 210 may result in a reduction in film thickness at the peripheral region of the substrate. However, anodized coatings are more porous than bare aluminum. While porosity increases particle retention, there is a possibility that some particles may fall off and contaminate the film formed on the substrate. Additionally, anodized coatings have different properties than bare aluminum. These properties include hardness, coefficient of thermal expansion, and the like. Differences in properties can lead to microcracking and/or peeling of anodized coatings and particle contamination. Thus, one skilled in the art can strike a balance between competing film uniformity and particle issues to achieve an optimal anodized area relative to bare aluminum. Theshowerhead 200 as described herein can minimize the risk of particle contamination as an airflow effect. Theshowerhead 200 also optimizes device design rules by controlling the purity of the deposited film.Showerhead 200 with anodizedperipheral region 210 and exposedcentral region 215 provides the desired plasma density and manages film deposition uniformity.

图3是根据另一实施方式的喷头300的示意性截面图。喷头300可在设备100中用作喷头116。如图2所示，喷头300包括第一表面区域240(周边区域210)和第二表面区域245(中心区域215)。FIG. 3 is a schematic cross-sectional view of ashowerhead 300 according to another embodiment.Showerhead 300 may be used asshowerhead 116 inapparatus 100 . As shown in FIG. 2,showerhead 300 includes a first surface area 240 (perimeter area 210) and a second surface area 245 (central area 215).

喷头300具有多个气体通道156，这些气体通道156在面对背板114(图1所示)的上游侧305(背面159)与下游侧310(前面160)之间穿过。下游侧310被示出为面向基板凹入。应理解，在一些实施方式中，下游侧310可为平坦的并基本上平行于上游侧305。在一个实施方式中，喷头300的上游侧305也可为凹形的。气体通道156具有气室315、孔口320和中空阴极空腔325。孔口320在喷头305的上游侧305上产生背压。由于背压，气体可在穿过气体通道156之前均匀地分布在喷头300的上游侧305上。中空阴极空腔325允许在中空阴极空腔325中使得等离子体在气体通道156内产生。与不存在中空阴极空腔的情况相反，中空阴极空腔325允许更大程度地控制处理腔室内的等离子体分布。下游侧310处的中空阴极空腔325具有比孔口320大的直径或宽度。孔口320的宽度或直径小于等离子体暗空间，因此，预期等离子体不会在中空阴极空腔325上方发光。Showerhead 300 has a plurality ofgas passages 156 passing between upstream side 305 (back side 159 ) and downstream side 310 (front side 160 ) facing back plate 114 (shown in FIG. 1 ).Downstream side 310 is shown concave facing the substrate. It should be appreciated that in some embodiments,downstream side 310 may be flat and substantially parallel toupstream side 305 . In one embodiment, theupstream side 305 of theshowerhead 300 may also be concave.Gas channel 156 hasgas chamber 315 ,orifice 320 andhollow cathode cavity 325 . Theorifices 320 create back pressure on theupstream side 305 of theshowerhead 305 . Due to the back pressure, the gas may be uniformly distributed over theupstream side 305 of theshowerhead 300 before passing through thegas channel 156 . Thehollow cathode cavity 325 allows plasma to be generated within thegas channel 156 in thehollow cathode cavity 325 . Thehollow cathode cavity 325 allows for greater control of the plasma distribution within the processing chamber, as opposed to the absence of a hollow cathode cavity. Thehollow cathode cavity 325 at thedownstream side 310 has a larger diameter or width than theorifice 320 . The width or diameter of theapertures 320 is smaller than the plasma dark space, therefore, the plasma is not expected to emit light above thehollow cathode cavity 325.

喷头300还具有凸缘330，该凸缘300朝着腔室壁(图1所示出的壁146)延伸。在图3所示出的实施方式中，阳极化层170沿喷头300的外表面和内表面形成。在图3所示出的实施方式中，阳极化层170设置在凸缘330上方至凸缘330内侧的位置。阳极化层170还可防止喷头300与腔室壁之间发生电弧放电。在图3所示出的实施方式中，阳极化层170至少部分地覆盖上游侧305和下游侧310。在图3所示出的实施方式中，阳极化层170设置在周边区域210处的气体通道156的表面上。Theshowerhead 300 also has aflange 330 that extends toward the chamber wall (wall 146 shown in FIG. 1 ). In the embodiment shown in FIG. 3 , theanodized layer 170 is formed along the outer and inner surfaces of theshowerhead 300 . In the embodiment shown in FIG. 3 , theanodized layer 170 is provided at a position above theflange 330 to the inside of theflange 330 . Theanodized layer 170 also prevents arcing between theshowerhead 300 and the chamber walls. In the embodiment shown in FIG. 3 , theanodized layer 170 at least partially covers theupstream side 305 and thedownstream side 310 . In the embodiment shown in FIG. 3 , theanodized layer 170 is disposed on the surface of thegas channel 156 at theperipheral region 210 .

图4是根据一个实施方式的气体分配喷头400相对于处理腔室壁405的示意性截面图。如图4所示，喷头400的凸缘330靠近壁405延伸。喷头400通过吊架410悬挂在背板114(图1所示)上。沉积在凸缘330上的阳极化层170充当绝缘体，以增加阻抗并减慢沿喷头400行进的RF电流。阳极化层170可防止电子从喷头400的高RF电势跳到壁405的低RF电势。阳极化层170可足够薄以允许RF电流沿喷头400继续行进。然而，阳极化层170的存在将足够厚以防止或减少喷头400与壁405之间的电弧放电。4 is a schematic cross-sectional view of agas distribution showerhead 400 relative to aprocess chamber wall 405, according to one embodiment. As shown in FIG. 4 , theflange 330 of theshowerhead 400 extends adjacent thewall 405 . Theshowerhead 400 is suspended from the backing plate 114 (shown in FIG. 1 ) by thehanger 410 .Anodized layer 170 deposited onflange 330 acts as an insulator to increase impedance and slow down RF current traveling alongshowerhead 400 .Anodized layer 170 prevents electrons from jumping from the high RF potential ofshowerhead 400 to the low RF potential ofwall 405 .Anodized layer 170 may be thin enough to allow RF current to continue alongshowerhead 400 . However, the presence ofanodized layer 170 will be thick enough to prevent or reduce arcing betweenshowerhead 400 andwall 405 .

在一个实施方式中，如箭头“D”所示，阳极化层170的厚度可在约1微米(μm)至约2μm之间。在另一个实施方式中，阳极化层170可具有大于约2μm的厚度。相反，如本文所述，喷头的中心区域215的原生氧化物层的厚度为约50埃或更小。In one embodiment, as indicated by arrow "D", the thickness of the anodizedlayer 170 may be between about 1 micrometer (μm) to about 2 μm. In another embodiment, theanodized layer 170 may have a thickness greater than about 2 μm. In contrast, as described herein, the thickness of the native oxide layer in thecentral region 215 of the showerhead is about 50 angstroms or less.

为了在喷头300的表面上形成阳极化层170，可首先通过在其中钻出气体通道156来形成喷头300。可在钻孔之前或之后使下游侧310凹入。无论如何，在形成喷头300之后，喷头300很脏并需要清洁。在一些实施方式中，喷头300可被清洁。在清洁之后，喷头300的周边区域210可被阳极化。To formanodized layer 170 on the surface ofshowerhead 300,showerhead 300 may first be formed by drillinggas passages 156 therein. Thedownstream side 310 may be recessed before or after drilling. In any event, after theshowerhead 300 is formed, theshowerhead 300 is dirty and needs cleaning. In some embodiments, theshowerhead 300 can be cleaned. After cleaning, theperipheral region 210 of theshowerhead 300 may be anodized.

在一个实施方式中，为了在清洁之后获得阳极化层170，可将周边区域210放置在电解浴中。喷头300的每一侧可在指定电压或电流下进行涂覆，然后旋转90度以涂覆另一侧。每一侧浸没的深度对应于距离220和距离225(在图2中描述)。无需掩模或其他工具即可在周边区域210上形成阳极化层170。In one embodiment, in order to obtain theanodized layer 170 after cleaning, theperipheral region 210 may be placed in an electrolytic bath. Each side of theshowerhead 300 can be coated at a specified voltage or current and then rotated 90 degrees to coat the other side. The depth of immersion on each side corresponds to distance 220 and distance 225 (described in Figure 2). Theanodized layer 170 may be formed on theperipheral region 210 without a mask or other tools.

在另一个实施方式中，阳极化层170可包括聚四氟乙烯。在另一个实施方式中，阳极化层170可包括有机材料。In another embodiment, theanodized layer 170 may include polytetrafluoroethylene. In another embodiment, theanodized layer 170 may include an organic material.

进行了如本文所述的在其上具有阳极化层170的喷头的测试，并且结果显示，与常规喷头相比，基板上的膜厚度不均匀性最小并且颗粒产生最少。通过在喷头的一部分上而不在喷头的其余部分上具有阳极化层170，可调整等离子体密度，这最小化跨越基板的膜厚度不均匀性。通过利用喷头的第一表面区域240上的阳极化层170，并使第二表面区域245裸露，可实现沉积厚度的均匀性以及跨越基板的膜性质。Tests of the showerhead with theanodized layer 170 thereon as described herein were performed and the results showed minimal film thickness non-uniformity and minimal particle generation on the substrate compared to conventional showerheads. By having the anodizedlayer 170 on a portion of the showerhead and not on the remainder of the showerhead, the plasma density can be adjusted, which minimizes film thickness non-uniformity across the substrate. By utilizing theanodized layer 170 on thefirst surface area 240 of the showerhead, and leaving thesecond surface area 245 exposed, uniformity of deposition thickness and film properties across the substrate can be achieved.

尽管前述内容针对的是本公开内容的实施方式，但是在不脱离本公开内容的基本范围的情况下，可设想其他和进一步实施方式，并且被公开内容的范围由随附权利要求书确定。While the foregoing has been directed to embodiments of the present disclosure, other and further embodiments may be contemplated without departing from the essential scope of the present disclosure, and the scope of the disclosed content is to be determined by the appended claims.

Claims (20)

1. A gas distribution showerhead, comprising:

a body having a plurality of gas passages extending through the body from an upstream side to a downstream side, the body having a central region and a peripheral region, the peripheral region having an anodization layer disposed on the upstream side and the downstream side.

2. The gas distribution showerhead of claim 1, wherein the anodization layer is disposed on a surface of a portion of the plurality of gas passages.

3. The gas distribution showerhead of claim 1, wherein the peripheral region further comprises:

a flange portion on which the anodization layer is disposed.

4. The gas distribution showerhead of claim 1, wherein the body comprises aluminum.

5. The gas distribution showerhead of claim 4, wherein the aluminum comprises bare aluminum.

6. The gas distribution showerhead of claim 4, wherein the anodization layer comprises a material selected from the group consisting of: al (Al)₂O₃、SiO₂Polytetrafluoroethylene, and combinations thereof.

7. The gas distribution showerhead of claim 6, wherein the anodized layer has a thickness between about 1 micron and about 2 microns.

8. The gas distribution showerhead of claim 1, wherein the peripheral region comprises a first surface area of the body and the central region comprises a second surface area of the body, and a percentage of the first surface area relative to the second surface area is about 20% to about 25%.

9. A plasma processing apparatus, comprising:

a process chamber body having a wall and a floor;

a susceptor disposed in the process chamber body and movable between a first position and a second position;

one or more straps coupled to the base and to one or more of the floor or the wall; and

a showerhead disposed in the process chamber body opposite the pedestal and having one or more gas passages extending therethrough, the showerhead comprising:

a body having a plurality of gas passages extending through the body from an upstream side to a downstream side, the body having a central region and a peripheral region, the peripheral region having an anodization layer disposed on the upstream side and the downstream side.

10. The apparatus of claim 9, wherein the anodization layer is disposed on a surface of a portion of the plurality of gas channels.

11. The apparatus of claim 9, wherein the peripheral region further comprises:

a flange portion on which the anodization layer is disposed.

12. The apparatus of claim 9, wherein the body comprises aluminum.

13. The apparatus of claim 12, wherein the aluminum comprises bare aluminum.

14. The apparatus of claim 12, wherein the anodization layer comprises a material selected from the group consisting of: al (Al)₂O₃、SiO₂Polytetrafluoroethylene, and combinations thereof.

15. The apparatus of claim 14, wherein the anodization layer has a thickness of between about 1 micron and about 2 microns.

16. The gas distribution showerhead of claim 9, wherein the peripheral region comprises a first surface area of the body and the central region comprises a second surface area of the body, and a percentage of the first surface area relative to the second surface area is about 20% to about 25%.

17. A plasma enhanced chemical vapor deposition apparatus, comprising:

a chamber body having a plurality of walls and a chamber floor;

a susceptor disposed in the chamber body and movable between a first position spaced apart from the chamber floor by a first distance and a second position spaced apart from the chamber floor by a second distance greater than the first distance;

a plurality of straps coupled to the base and to one or more of the chamber floor and the plurality of walls, the plurality of straps being unevenly distributed along the base; and

a gas distribution showerhead disposed in the chamber body opposite the pedestal, the gas distribution showerhead having a plurality of gas passages extending therethrough and having a center portion and a rim portion, the gas distribution showerhead comprising:

a body having a plurality of gas passages extending through the body from an upstream side to a downstream side, the body having a central region and a peripheral region, the peripheral region having an anodization layer disposed on the upstream side and the downstream side.

18. An apparatus as in claim 17, wherein the anodization layer is disposed on a surface of a portion of the plurality of gas channels.

19. The apparatus of claim 17, wherein the body comprises bare aluminum.

20. The gas distribution showerhead of claim 17, wherein the peripheral region comprises a first surface area of the body and the central region comprises a second surface area of the body, and a percentage of the first surface area relative to the second surface area is about 20% to about 25%.

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