JP3946660B2 - Method for producing halogen-resistant semiconductor processing device member - Google Patents

Description

【００７０】
この結果から明らかなように、比較例のSUS３１６鋼無処理（Ｎｏ．６）では、Ｆ₂ガスの腐食作用によって表面に小さな凹部が生成し、特に３００℃の温度では多数の腐食痕の発生が見られた。また、SUS３１６鋼にＴｉ、Ｎｂ、Ｔａなどの金属イオンを注入した試験片（Ｎｏ．７〜９）でも、微小な腐食痕の発生が認められ、耐Ｆ₂ガス性に乏しいことが判明した。
【００７１】
これに対し、試験片（Ｎｏ．１〜５）は２５℃の場合はもちろん３００℃の高温においても、外観上全く変化は認められなかった。そこで、試験片の表面部をＡＥＳによって調査すると、Ｎｏ．１ではＡｌＦ_ｘ、Ｎｏ．２ではＢａＦ_ｘ、Ｎｏ．３ではＣａＦ_ｘ、ＮＯ．４ではＭｇＦ_ｘ、Ｎｏ．５ではＹＦ_Ｘ（但しＸ＝１〜３）が生成するとともに、注入イオン金属が濃化して耐Ｆ_２ガス性を発揮していることが判明した。
【００７２】
＜参考例２＞
この参考例では、金属製基材の表面に各種の表面処理法によって金属質の皮膜を形成させたあと、この皮膜に対して金属のイオンをプラズマイオン注入法で注入し、参考例１と同じＦ₂ガス中で注入金属の濃化状況を観察した。比較例のイオン注入金属としてＴｉ、Ｎｂ、Ｔａ、Ｓｉ、Ｆｅを同条件で注入し、同条件のF₂ガス中の濃化試験を行なった。表２はこの結果を要約したものである。
【００７３】
【表２】

【００７４】
この結果から明らかなように、金属イオンは溶射皮膜（Ｎｏ．１、２）、電気めっき皮膜（Ｎｏ．３、４）、ＰＶＤ皮膜（Ｎｏ．５、６）であっても、それぞれの皮膜の表面部には注入金属の濃化層が明瞭に認められ、耐ハロゲンガス性を発揮していることがわかる。
【００７５】
これに対して、比較例の金属イオンを注入した皮膜（Ｎｏ．７〜１２）には、注入金属の濃化現象は全く認められず、蒸気圧の高い金属フッ化物を生成するとともに、これが蒸気化し、揮散している様子がうかがえる。
【００７６】
＜参考例３＞
この参考例では、ＳＵＳ３０４鋼とＡｌ（ＪＩＳＨ４０００、Ａ１０７０）（２０ｍｍ×３０ｍｍ×３ｍｍ）の試験片を用い、その表面にイオン注入法とプラズマイオン注入法を用いて、ＣａとＭｇ金属イオンをそれぞれ１×１０^１８／ｃｍ^２濃度に注入した後、ＣＦ_４とＮＦ_３の１００ｈＰａの雰囲気中で３００℃×２４時間の曝露試験を行ない、金属イオン注入面の腐食状況を調査した。
【００７７】
この参考例では、比較例として無処理のＳＵＳ３０４ステンレス鋼、Ａｌ（Ａ１０７０）とともにＴｉ、Ｔａの金属イオン注入試験片を同条件で曝露した。表３はこの結果を示したものである。
【００７８】
【表３】

【００７９】
この曝露試験では、無処理のＳＵＳ３０４鋼（Ｎｏ．１７）は赤色粉末状の腐食生成物を多量に生成し、無処理のＡｌ（Ｎｏ．１８）では、大きな腐食痕は認められないものの表面は梨地状の腐食形態を呈していた。また、Ｔｉ、Ｔａを注入した試験片（No．９〜１６）では基材がＳＵＳ３０４鋼（No．９〜１２）のときはもとより、Ａｌ基材（No．１３〜１６）の場合にもフッ化ガスによる腐食作用によって大きな腐食痕の生成が認められた。
【００８０】
これに対し、Ｃａ、Ｍｇ金属イオンを注入した試験片では、基材がＳＵＳ３０４鋼（Ｎｏ．１〜４）のときも、またＡｌ基材（Ｎｏ．５〜８）の場合にも、外観的には全く腐食の発生は認められなかった。またＣａ、Ｍｇの金属イオンの注入は、イオン注入法でもプラズマイオン注入法でもほぼ同等の防食効果が得られた。
【００８１】
＜実施例１＞
この実施例では、ＳＵＳ３０４ステンレス鋼試験片を用いて、プラズマイオン注入法によって、本発明に属する金属イオンを積層注入した場合の耐ハロゲンガス性を調査した。すなわち基材に対し一次注入としてＡｌを１×１０^１２／ｃｍ^２濃度注入した後、その上にＭｇを１×１０^１２／ｃｍ^２濃度注入したり、ＡｌやＭｇを積層注入した後、さらにその上に注入エネルギーを小さくして、Ａｌおよび５０％Ａｌ−５０％Ｍｇ合金の薄膜を形成させた。このものを耐ハロゲンガス性をＦ_２、ＮＦ_３の１００ｈＰａ、３００℃の雰囲気中で２４時間曝露することによって調査した。この結果は表４に示す通りである。
【００８２】
【表４】

【００８３】
本参考例の金属イオンは、積層注入しても、また注入金属を薄膜化しても耐ハロゲンガス性を発揮することが判明した。
【００８４】
＜参考例４＞
この参考例では、参考例１と同じＳＵＳ３１６鋼試験片を用い、これにプラズマイオン注入法によって，５０Ａｌ−５０Ｍｇ、Ｍｇ、Ｂａ、Ｃａ、Ｙの金属イオンを１×１０^１８／ｃｍ^２注入した後、下記のようなプラズマで励起された含Ｆ_２ガス雰囲気中に１０時間曝露した。この曝露試験室には直径８インチのシリコンウエハーを静置し、１０時間後にウエハーの表面に付着するパーティクル粒子（環境汚染粒子）の数を、拡大鏡を用いて観察記録した。拡大鏡で観察記録可能な粒子径は概ね０．２μｍ以上であった。
【００８５】
試験環境の構成は以下の通りである。
（１）雰囲気ガス：ＣＦ₄／Ａｒ／Ｏ₂の混合割合は、容量比で１００／１００／１０ｃｍ³、ガスの圧力１００Ｐａ、温度６０℃
（２）プラズマ照射出力：高周波電力：１３００ｗ×１０時間
なお、この試験には、比較例として無処理のSUS３１６鋼、陽極酸化（アルマイト）したAｌに加え、SUS３１６鋼にプラズマイオン注入法によってＴｉ、Ｎｂの金属イオンを１×１０¹⁸／ｃｍ²注入したものを同条件で試験した。表５は以上の試験結果を要約したものである。
【００８６】
【表５】

【００８７】
この結果から明らかなように、比較例の試験片（Ｎｏ．６〜９）は１０時間の曝露後、シリコンウエハーの表面に１００個以上のパーティクル粒子が付着し、環境の汚染源となることが明らかとなった。なお、これらのパーティクル粒子の成分を調査すると、ステンレス鋼試験片の場合はＦｅ、Ｃｒ、Ｎｉのフッ化物、Ａｌ基材の場合はＡｌとFを主成分とするものであり、雰囲気のＣＦ₄によって誘発された腐食生成物であることが判明した。ＴｉやＮｂを注入した試験片（Ｎｏ．６、７）では、ＴｉとＮｂのフッ化物粒子が多量に認められ、プラズマが付加されたハロゲンガス雰囲気中では、耐食性に乏しいことが認められた。
【００８８】
これに対し、試験片（Ｎｏ．１〜５）は、１０時間の曝露試験を行なっても、シリコンウエハー表面に付着するパーティクル数は、何れも３０個以下であり、優れた耐ハロゲン環境性を有することがわかった。
【００８９】
【発明の効果】
以上詳述したように、金属製基材の表面に、イオン注入法やプラズマイオン注入法によって、Ｂａ、Ｍｇ、Ｙから選ばれる１種以上の金属イオンを注入するとともに、薄膜を形成することによって、耐ハロゲンガス性、特にＦ₂ガスおよびフッ化物ガスに対する化学的抵抗性が著しく向上する。
【００９０】
本発明の方法で基材表面に注入されたＢａ、Ｍｇ、Ｙなどの金属は、Ｆ_２ガスが含まれている環境下ではそれぞれの金属が、蒸気圧の低いフッ化物層を形成することによって優れた耐ハロゲンガス性を発揮する。
【００９１】
以上の金属イオンの注入機構と耐ハロゲンガス性は、半導体加工装置部材の長寿命化に加え、装置部材の腐食生成物の減少によって半導体加工環境の汚染を最小限にとどめることができるので、半導体の高精度加工を可能とし、製品の信頼性および生産性の向上に大きく貢献することが期待できる。
【００９２】
また、金属イオン注入層は最大３００ｎｍ程度にする場合には、精密加工された半導体加工装置部材の形状や寸法に影響を与えることがない。
【００９３】
また、プラズマイオン注入法による金属イオンの注入の場合は、被処理体が三次元次元的な構造を有するものであっても、均等に注入することが可能であるうえ、複数の金属イオンの同時注入も容易である。
【図面の簡単な説明】
【図１】 金属イオン注入装置の概略図。
【図２】 プラズマイオン注入装置の概略図。
【図３】 本発明による金属イオン注入処理を施工した被処理体表面の断面を示す図。
【符号の説明】
１ イオン源ガス導入口
２ イオン発生室
３ 加速器
４ 質量分離器
５ ビーム走査系
６ ターゲット試料（被処理体）
２１ 金属製の処理容器
２２ 被処理体
２３ 直流電源
２４ 気相系イオン源
２５ 金属系イオン源
２６ 真空ポンプ図外
２７ 気圧調整弁
２８ 金属イオンを含むプラズマ
３１ 被処理体
３２ 金属イオン注入層
３３ 金属薄膜
３４ 金属溶射皮膜のうちイオン注入されていない部分 [0001]
BACKGROUND OF THE INVENTION
The present invention relates to a halogen-resistant gas member as a surface treatment member that exhibits excellent corrosion resistance in an environment containing various halogen gases, particularly fluorine and its compounds, and a method for producing the same.
[0002]
In general, in a semiconductor manufacturing process, an environment in which a variety of halogen gases and their compounds are in a gas phase state, and sometimes a part of them is in a liquid phase, is formed in each step, and thus a manufacturing apparatus member is severely damaged by corrosion. The following corrosive gas species are handled by semiconductor manufacturing equipment.
Fluoride: BF_Three, PF_Three, PF₆, NF_Three, WF_Three, CF_Four, HF, F
Chloride: BCl_Four, PCl_Three, PCl_Five, AsCl_Three, SnCl_FourTiCl_Four, SiH₂Cl₂, SiCl_Four, HCl, Cl₂
Bromide: HBr
Other: H₂S, NH_Three,Such
[0003]
In particular, in a process using a halogen compound, plasma energy is often used together in order to further activate the reaction. However, in this plasma usage environment, the halogen compound is ionized and is very corrosive and has atomic F. , Cl, Br, I, etc. are generated at the same time as SiO in the environment.₂, Si_ThreeN_FourWhen fine powdered solids such as Si and W are generated, the members used in the apparatus are strongly affected by both erosion damage due to fine particles as well as chemical corrosion.
[0004]
Moreover, the environment in which the plasma is excited is ionized even in a non-corrosive gas such as Ar gas, and a phenomenon in which this strongly collides with the solid surface (called ion bombardment) occurs. It is also known that the various members are more severely damaged.
[0005]
On the other hand, since semiconductors are precisely processed, the manufacturing environment is required to be extremely clean. However, the metal halide produced as a result of the corrosion reaction of the device material with various halogen compounds as described above is a source of contamination in the gas phase due to its high vapor pressure, and it is a fine powder solid matter generated by the plasma erosion action. At the same time, it is a major source of environmental pollution in semiconductor processing. In order to solve the above problems, the following techniques have been proposed.
[0006]
That is, as in Patent Document 1 below, various intermetallic compounds (for example, Al—Fe, Al—Ni, Al—Cr, etc.) containing Al as a main element by performing Al diffusion treatment on the surface of a member of a semiconductor processing apparatus Al produced on the surface₂O_ThreeSome use the halogen gas resistance of the film.
[0007]
Further, as described in Patent Document 2 below, as a film resistant to halogen-based corrosive gas or halogen plasma, the thermal expansion coefficient is 7 × 10.^-6~ 12x10^-6, Dielectric loss is 5 × 10^-3Direct Y on the surface of the following non-metallic sintered bodies₂O_Three, Dy₂O_Three, Er₂O_ThreeSome of them form an oxide film containing 50% or more of a rare earth oxide.
[0008]
In addition, as disclosed in Patent Document 3 below, Ni, W, Mo, Ti, and alloys thereof are used as an undercoat as a technique having plasma erosion resistance in an environment containing F compound, and Y is formed thereon.₂O_ThreeAnd Y₂O_ThreeAnd Al₂O_ThreeThere is a thermal spray coating with a mixture of
[0009]
In addition, as described in Patent Document 4 below, oxides, carbides, and nitrides of Group 3a elements of the periodic table such as Sc, Y, La, Ce, Yb, Eu, and Dy are formed on the surface of the member by PVD or CVD. , Forming a dense film such as fluoride, Y₂O_ThreeThere is a technique that applies a single crystal.
[0010]
Further, as in Patent Document 5 below, after coating one surface of the corrosion-resistant metal substrate with Al or an Al alloy by a method other than the thermal spraying method, this is coated on the coated surface by an anodic oxidation method.₂O_ThreeThis layer is produced and this Al₂O_ThreeLayer or Al₂O_ThreeThere is a corrosion-resistant material by a plasma-excited halogen gas in which an aluminum fluoride layer having corrosion resistance is formed without using a layer.
[0011]
[Patent Document 1]
JP-A-10-219456
[Patent Document 2]
JP 2001-031484 A
[Patent Document 3]
JP 2000-164354 A
[Patent Document 4]
JP-A-10-004083
[Patent Document 5]
Japanese Patent Laid-Open No. 9-10777
[0012]
[Problems to be solved by the invention]
However, according to Patent Document 1-5, there are various limitations on the metal base material, film composition, etc. in film formation, and corrosion damage of equipment members due to halogen gas that current semiconductor processing equipment has and the like. There is a problem that it is not sufficient for preventing the occurrence of a defective rate of semiconductor products or the like due to contamination of the processing environment due to the volatilization of the corrosion products.
[0013]
The present invention relates to halogen gas, particularly fluorine (F₂) It is an object of the present invention to provide a metal member for a semiconductor processing apparatus or the like that comes into contact with a gas and a fluoride gas, and is excellent in halogen gas resistance, and a method for manufacturing the metal member.
[0014]
[Means for Solving the Problems]
  In order to solve the above problems, the present invention achieves the object by using the following technical means..
[0020]
(1) Use ion implantation or plasma ion implantation on the surface of metal substrateAndBa,One or more selected from Mg and YImplanted metal ionsAfter the metal ion implantation layer is provided, Al is further deposited thereon by plasma ion implantation.,Ca,Mg1-30 μm thick thin film containing one or more metals selected fromlayerIt is characterized by further improving halogen gas resistance by laminatingFor halogen processing semiconductor processing equipmentA method for manufacturing a member is proposed.
[0021]
(2) Use ion implantation or plasma ion implantation on the surface of metal substrateAndBa,One or more selected from Mg and YImplanted metal ionsAfter providing the metal ion implantation layer,Furthermore, after laminating a thin film layer containing one or more metals selected from Al, Ca, and Mg by plasma ion implantation,By heating at a temperature of 200 ° C. to 750 ° C. for 0.5 to 5 hours,Metal ionsIt features micro-stress removal of the injection layer and stability of crystal structure, and further improves excellent halogen gas resistance.For halogen processing semiconductor processing equipmentA method for manufacturing a member is proposed.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a halogen-resistant gas film covering member and a manufacturing method thereof according to an embodiment of the present invention will be described.
[0024]
The halogen-resistant gas film covering member is formed by using an ion implantation method or a plasma ion implantation method on the surface of a metal substrate.₂An ion-implanted layer of one or more metal elements selected from Al, Ba, Ca, Mg, and Y, which reacts with gas and fluoride gas but has a low vapor pressure of the reaction product, is provided.
[0025]
In this example, Mg ions, which are one of the implanted metal ions belonging to the present invention, are implanted into an Al alloy substrate as an example.₂The mechanism of corrosion reaction with gas and its preventive action will be described.
[0026]
<Al alloy base material implanted with Mg ions and F₂Corrosion reaction with gas>
Fluorine (F) has a very strong chemical reactivity and is known as an element that corrodes siliconaceous materials and is widely used in semiconductor processing processes. F₂The strength of the chemical reactivity of the gas is suitable for processing a silicon wafer or a thin glass plate, but it also causes an increase in the corrosive action on the components of the semiconductor processing apparatus.
[0027]
In general, the corrosion resistance of a metal material is governed by the presence or absence of an oxide film (passive film) formed on its surface and its chemical stability.₂Corrosion resistance of the metal material in the gas is also generated on the surface of the metal material.₂The stability of the reaction product (metal fluoride) with the gas plays a crucial role.
[0028]
Now, when the surface of the Al alloy base material into which Mg ions are implanted is microscopically observed, the main metal elements are Al, Fe, Si, etc. constituting the Al alloy together with the implanted Mg. Is in a state. A comparison of the stability of the fluorides of the respective metal elements from the viewpoint of vapor pressure is as follows.
MgF₂<AlF_Three<FeF₂<SiF_Four
(Steam pressure low / stable) (Steam pressure high / unstable)
As is apparent from this result, the lowest vapor pressure fluoride is MgF.₂It is. MgF is applied to the surface of the Al alloy substrate into which Mg ions are implanted.₂When the film is formed, F₂In an environment containing gas, it becomes possible to maintain a very stable state and reduce the corrosion rate. This is the biggest reason why the present invention selects Mg as the ion-implanted metal element.
[0029]
In the present invention, using the principle as described above, MgF is applied to the surface of a metal substrate not containing Mg.₂A method has been devised to produce a highly protective film. That is, protective MgF₂If Mg that forms a film is injected into the surface of a metal substrate in an ionic state, F₂When in contact with the gas, fluorides of metal elements other than Mg have high vapor pressures, and thus volatilize and desorb from the substrate surface. On the other hand, on the surface of the base material into which Mg ions are implanted, MgF having a gradually lower vapor pressure with the passage of time.₂The residual ratio of slag increases and soot is MgF₂A coating is formed. (Here, this phenomenon is called concentration phenomenon)
[0030]
Such MgF₂Since the concentration phenomenon occurs in the very vicinity of the substrate surface, the present invention uses an ion implantation method or a plasma ion implantation method, which will be described later, to target only a depth of about 300 nm from the surface. An ion implantation layer was provided.
[0031]
In the present invention, the same F resistance as Mg₂Ba, Ca, and Y were selected by experiment as metals for forming a protective film, and Al was found to exhibit a useful mechanism of action. It was made into the scope of the present invention.
[0032]
<Metal ion implantation method>
There are two types of methods for injecting metal ions and metal base materials belonging to the present invention, and each method will be described in detail.
[0033]
(A) Linear metal ion implantation method
Mg, Al, Ba, Ca, and Y (hereinafter abbreviated as Mg and the like) are suitable as metal ions to be injected into the surface of the metal substrate. These metal ions are in vacuum, eg 1 × 10^-FourA metal such as Mg is ionized with Pa, accelerated by an electrostatic field, and injected impactively onto the substrate surface. FIG. 1 shows an outline of a metal ion implantation apparatus.
[0034]
This apparatus mainly includes an ion source gas inlet 1, an ion generation chamber 2, an electrostatic accelerator 3, a mass separator 4, a beam scanner 5, a target sample (test piece) 6, and a vacuum exhaust system 7 (all not shown). ).
[0035]
Since a metal such as Mg is in a solid state at room temperature, the metal is ionized using a heat source such as an electron beam or a sputtering phenomenon, or a halogen compound such as Mg is vaporized, and then the inside of the ion generation chamber 2. To be ionized. Thereafter, the ionized metal is collided with the surface of the substrate in the state where the electric field is accelerated by the accelerator 3 to form an ion beam.
[0036]
Ion implantation is 1cm²1 × 10¹²~ 1x10^{twenty two}A range of 1 is appropriate, 1 × 10¹²The effect of the injected metal is not sufficient with a smaller injection amount, and 1 × 10^{twenty two}Even if the above injection is carried out, no significant difference in the effect is recognized, so that the treatment takes a long time and is not economical.
[0037]
On the other hand, metal ions such as Mg colliding with the substrate surface have different penetration depths into the substrate depending on their kinetic energy, but a range of 1 KeV to 1000 KeV is suitable for obtaining the effects of the present invention. Yes. When the kinetic energy of the implantation is small, the metal ions are not sufficiently implanted into the substrate, and the metal is simply deposited on the surface (thin film). Even in this state, if the usage environment is a static state, it can be fully utilized.
[0038]
(B) Plasma ion implantation method (high density pulse plasma ion implantation apparatus)
In the metal ion implantation method described above, after mass separation in a vacuum environment of ions, only the necessary ion species are selected, and this is accelerated and implanted into the substrate surface, so that the surface of the substrate is in a flat state. It is necessary to be, and injection into a substrate having a three-dimensional structure is difficult. Also, only one type of metal ion can be processed in a single implantation operation.
[0039]
Therefore, we decided to use a phenomenon in which only metal ions are injected into the surface of the substrate by creating a plasma environment of metal ion species such as Mg using a metal ion source and applying a negative pulse voltage to the substrate. .
[0040]
FIG. 2 is a schematic view of a plasma ion implantation apparatus used in the present invention. In the apparatus, the object to be processed 22 is placed in a metal processing container 21 and each is connected to a power source 23, and the former is arranged to be a “+” pole and the latter is a “−” pole. Yes. In addition, a metal processing vessel includes a gas phase ion (for example, oxygen, nitrogen, argon, etc.) source 24, a metal ion source 25, etc., a vacuum pump 26 (not shown) for controlling the environment in the vessel, and atmospheric pressure. A regulating valve 27 is attached.
[0041]
After removing the air in the processing vessel using a vacuum pump, a metal ion species is introduced, and a negative pulse voltage (for example, pulse width 2 μs to 30 μs, applied voltage −1 kV to −50 kV, pulse repetition 1000 to several thousand pps is applied to the substrate. ) Is applied, the electrons in the plasma 28 surrounding the object to be processed have a negative charge, so that they are repelled from the surface of the object to be processed at the “−” pole and fly away, and only metal ions having a positive charge are present. The rest collides with the surface of the object to be processed having a negative pulse potential. Also in this case, when the applied voltage is high, it is injected into the inside of the substrate, and when it is low, it becomes a thin film like a film formed by ordinary ion plating on the surface.
[0042]
The feature of this method is that the plasma 28 containing metal ions generated when the object to be processed is applied with a negative pulse voltage is generated along the surface of the object to be processed. In contrast, metal ions can be implanted equally. Even if objects to be processed having different shapes and dimensions are put together in a container, they can be processed at the same time, which can greatly help to improve productivity. In addition, the feature of this method is that when a Mg—Al alloy is used as a metal ion source, both metal ions can be implanted simultaneously, and metal ions such as Ba, Ca, and Y can be implanted simultaneously as appropriate.
[0043]
Also, Ar, He, N in the plasma environment₂When gas molecules such as these coexist, these gases also become ions and are injected into the surface of the object to be processed simultaneously with the metal ions, but are not limited by such a phenomenon.
[0044]
The depth of the metal ion implantation layer that provides the effects of the present invention is preferably about 300 nm from the surface. Even if the depth is greater than 300 nm, no significant difference is observed in the halogen gas resistance effect. It is difficult to generate an injection layer having the above depth.
[0045]
On the other hand, the thickness of the metal thin film formed on the metal ion implantation layer with low implantation energy is preferably 1 to 30 μm. This is because it is difficult to control a thin film having a thickness of 1 μm or less, and even if a film having a thickness of 30 μm or more is used, an effect of improving the halogen gas resistance is not recognized.
[0046]
In the metal ion implantation method, as shown in FIG. 2, the metal ions charged to “+” collide with the surface of the object to be processed of the “−” electrode. Reduced to metal by electrons. At this time, since the metal expands its volume, the feature of densely covering the injection surface can be used.
[0047]
(C) When a metal excellent in halogen gas resistance is injected into the surface of a metal substrate by the above-described linear metal ion implantation method or plasma ion implantation method, a halogen gas, Especially F₂Semiconductor processing equipment components that come into contact with gas and fluoride gas are severely corroded, and the vapor pressure of the metal fluoride as the corrosion product is high, preventing this phenomenon from causing contamination of the equipment environment. A metal member having a metal ion implantation layer having excellent halogen gas properties can be formed.
[0048]
(D) In the methods such as hot dip plating treatment, diffusion penetration treatment, and pressure welding of Al and Al alloys that have been proposed as halogen-resistant surface treatment technology according to the prior art, a three-dimensional shaped member is treated with a uniform film thickness. In addition, since a large heat load is applied to the object to be processed, the effects of the member being deformed and the material being deteriorated are manifested, making it difficult to apply to a precision member. In addition, in the ion implantation method, it is necessary to implant metal ions at a 90 ° angle with respect to the surface of a flat metal substrate because of the straightness of metal ions. Uniform metal ion implantation is difficult, and a plurality of metal ions cannot be implanted at the same time. However, according to the plasma ion implantation apparatus described above, metal ions can be evenly implanted into a workpiece having a three-dimensional shape. Even if objects to be processed having different shapes and dimensions are put together in a container, they can be processed at the same time, which can greatly help to improve productivity. In addition, the feature of this method is that when a Mg—Al alloy is used as a metal ion source, both metal ions can be implanted simultaneously, and metal ions such as Ba, Ca, and Y can be implanted simultaneously as appropriate.
[0049]
<Metal base material to which the technology of the present invention can be applied>
The implantation of metal ions such as Mg of this embodiment can be applied to any substrate as long as it is a metal substrate such as aluminum and its alloys, magnesium and its alloys, carbon steel, various stainless steels, Ni-based alloys, Co-based alloys, etc. Is possible. In addition, when a metallic film is formed on the surface of the metal substrate by electroplating, thermal spraying, chemical vapor deposition (CVD), physical vapor deposition, etc. Even metal ions can be implanted.
[0050]
However, for the implantation of metal ions, even if metal ions such as Mg, Ca, and Y are directly implanted into aluminum and its alloys, magnesium and its alloys, etc.₂Gas properties can be obtained, but for carbon steel, stainless steel, etc., by first injecting Al ions and then injecting Ba, Ca, Mg, Y, F resistance₂Gasity is further improved.
[0051]
<Example of structure to metal ion implantation layer according to an embodiment of the present invention>
  FIG. 3 shows an example of a cross-sectional structure of a metal substrate provided with the metal ion implantation layer of the present invention.(B)Shown in3 (a) and 3 (c) are reference embodiments.Here, 31 is a metal substrate, 32 is a metal ion implantation layer, 33 is a metal thin film such as Mg, and 34 is a sprayed coating layer formed on the surface of the metal substrate.Of the part not ion-implantedIt is.
[0052]
  Figure3-(A) is a structural diagram when Mg ions are implanted into the surface of the Al alloy substrate, and the thickness of the implanted layer of metal ions is about 300 nm from the surface.
[0053]
  Figure3-(B) is the one in which Mg ions are implanted into the surface of the Al alloy substrate, and then the implantation energy is lowered to form a metal thin film (eg, Mg, Y, etc.) on the substrate surface. About 30 μm is preferable.
[0054]
  Figure3-(C) is a sprayed coating of an Al alloy on the surface of a stainless steel substrate(After the ion implantation, the metal ion implantation layer 32 and the portion that becomes the portion 34 of the metal spray coating that is not ion-implanted)After the surface is formed, ions such as Mg are implanted into the surface(Metal ion implantation layer 32)The thickness of the sprayed coating is preferably 30 to 150 μm.
[0055]
<Heat treatment after metal ion implantation layer and thin film formation>
The metal base material provided with the metal ion implantation layer can be put to practical use as it is. In addition, although the metal ion implantation layer is an aggregate of implanted metals, the volume change is very small and the depth is only 300 nm from the surface of the base material. Since it is not recognized, it can be applied to precision processed parts.
[0056]
However, considering the injection part into the metal ion microscopically, when the metal is shockedly injected near the surface of the base metal having a normal crystal structure, the crystal structure is distorted or some crystals are destroyed. is doing. In addition, the injected metal is not always dispersed at a uniform concentration.
[0057]
Then, after providing a metal ion implantation layer and forming a metal thin film on it, as needed, it is 200 degreeC-750 degreeC in the atmosphere of air | atmosphere, a vacuum, or an inert gas, and 0.5 to 5 hours. It is preferable to perform a heat treatment.
[0058]
By this heat treatment, residual stress resulting from the implantation of metal ions is released, and the implanted layer portion is stabilized by locally bonding the implanted metal and the base metal component.
In addition to densification of the thin film, it can be expected to improve the mutual bonding strength of the metal components constituting the thin film and the adhesion to the base metal, and if necessary, the thin film can be changed to a chemically stable oxide. It can also be made.
[0059]
When the heat treatment temperature is lower than 200 ° C., the above effect is poor, and when the temperature is 750 ° C. or higher, the injected metal does not stay on the surface of the base material but diffuses into the interior to lower the halogen gas resistance.
[0060]
<Application example>
The halogen-resistant member as described above is used as a surface treatment member that exhibits excellent corrosion resistance in an environment containing various halogen gases, particularly fluorine and its compounds.
In particular, it is used for a member disposed in a vacuum chamber used in dry etching processing in a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus, and protects against a corrosive action by an atmospheric gas or an erosion action by a plasma gas.
In addition to the above-mentioned fields, this halogen-resistant gas member includes, for example, an oxidation furnace, a CVD apparatus, an epitaxial growth apparatus, an ion implantation apparatus, a diffusion furnace, a reactive ion plating apparatus, plasma etching applied to a general dry process. The present invention can also be applied to apparatuses, sputtering apparatuses, and pipes, distribution air fans, valves, etc. as accessory equipment. In addition, it can be used for metals that clean the surface of a metal member in an environment containing fluorine.
[0061]
<Contrast with conventional example>
In Patent Document 1, although a technique using an Al-based intermetallic compound has a certain effect, Al and its alloys, to which Al diffusion treatment cannot be applied, are often used in semiconductor processing apparatus members. In addition, there are some which are thermally deformed by Al diffusion treatment, and there is a problem in accuracy as a structural member.
However, in the halogen-resistant gas member of this embodiment, one or more selected from Al, Al alloy, Mg alloy, Ti, Ti alloy, carbon steel, stainless steel, and Ni-based alloy can be selected as the metal substrate. . In addition, the base material surface may have a metal film formed by any one or more methods selected from a thermal spraying method, an electroplating method, an electroless plating method, and a physical vapor deposition method.
[0062]
In the technique of Patent Document 2, the technique of depositing a rare earth oxide on the surface of a non-metallic sintered body shows excellent resistance to halogen-resistant gas and halogen plasma, but this member itself is directly formed on a metal member. Can't membrane. Further, in this proposed technique, the thermal expansion coefficient is 7 × 10 10 even for a non-metallic sintered body.^-6~ 12x10^-6However, it cannot be said that it has solved the problems of current semiconductor processing equipment.
However, the halogen-resistant gas member of this embodiment can inject specific metal ions directly into a metal substrate. Further, since the metal ion implantation layer hardly affects the metal base material, it can be applied to precision parts.
[0063]
In Patent Document 3, the undercoat of Ni, W, Mo, Ti and alloys thereof is used, and Y is used as a topcoat thereon.₂O_ThreeIn the initial stage of use, Y₂O_ThreeExhibits excellent performance with respect to halogen gas plasma erosion possessed by, but when used for a long time, halogen gas penetrates into the inside of the film from the pores of the top coat, corrodes the undercoat, and as a result, only the top coat peels off Becomes apparent.
However, in this embodiment, the metal ion implantation layer formed on the surface of the metal substrate does not cause a problem of peeling.
[0064]
In the above-mentioned Patent Document 4, a technique for forming an oxide or carbide of an element of Group 3a of the periodic table such as Sc, Y, La, etc. on the member surface by CVD, PVD method, CVD method is PVD method, The CVD method alone has a problem that the film forming speed is slow and the productivity is inferior, and a uniform film cannot be formed on the surface of a member having a three-dimensional structure, so that it cannot be applied to a large member. Y₂O_ThreeAlthough single crystals can exhibit excellent halogen plasma erosion resistance, there is a drawback that their utility value is extremely small if there is no coating method for the members.
However, this embodiment does not cause such a problem.
[0065]
In Patent Document 5, it is difficult to clad an Al or Al alloy plate having a uniform thickness on the surface of a three-dimensional base material, and the clad Al alloy surface is anodized by anodizing.₂O_ThreeEven if the layer is formed, if the cladding is insufficient, sufficient corrosion resistance cannot be expected. Also, a method of coating the base material in a molten state of an Al alloy has been proposed. However, since the base material is thermally deformed, the melting process has a problem that it cannot be applied to a precision member.
However, in this embodiment, specific metal ions can be implanted directly into the metal substrate. Further, since the metal ion implantation layer hardly affects the metal base material, it can be applied to precision parts.
[0066]
After all, the halogen-resistant gas member according to the present embodiment has a defect in the semiconductor product due to the corrosion damage of the apparatus member due to the halogen gas that the current semiconductor processing apparatus has and the contamination of the processing environment due to the volatilization of the corrosion products. Prevent the generation of rates.
[0067]
  <referenceExample 1>
  thisreferenceIn the example, SUS316 stainless steel (20 mm × 30 mm × 3 mm) is used as a base material, and plasma ions are implanted into the surface, and metal ions of Al, Ba, Ca, Mg, Y are 1 cm.²1 × 10 per¹⁸Injected. After that, the test piece was Fc at 25 ° C. and 300 ° C. having a vapor pressure of 600 hPa₂The specimen was exposed to gas for 24 hours, the surface of the test piece was visually observed, and the behavior of the injected metal was investigated using a physical analyzer such as a glow discharge spectrometer.
[0068]
  thisreferenceIn the example, Ti, Nb, Ta metal ion implantation specimens implanted by the same method were exposed and compared under the same conditions. Table 1 compares the results.
[0069]
[Table 1]

[0070]
As is clear from this result, in the SUS316 steel untreated (No. 6) of the comparative example, F₂Small corrugations were generated on the surface due to the corrosive action of the gas, and numerous corrosion marks were observed particularly at a temperature of 300 ° C. Moreover, even in the test pieces (Nos. 7 to 9) in which metal ions such as Ti, Nb, and Ta are implanted into SUS316 steel, generation of minute corrosion marks is recognized and F₂It turned out to be poor in gas.
[0071]
  On the other hand, TryThe specimens (Nos. 1 to 5) showed no change in appearance even at a high temperature of 300 ° C. as well as at 25 ° C. Therefore, when the surface portion of the test piece was investigated by AES, No. 1 is AlF_x, No. 2 is BaF_x, No. 3 is CaF_x, NO. 4 is MgF_x, No. 5 is YF_X(However, X = 1 to 3) is generated and the implanted ion metal is concentrated to prevent F₂It has been found that it exhibits gas properties.
[0072]
<referenceExample 2>
  thisreferenceIn the example, after forming a metallic film on the surface of a metal substrate by various surface treatment methods,GoldImplant ions of the genus by plasma ion implantation,referenceSame F as in Example 1₂The concentration of the injected metal was observed in the gas. Ti, Nb, Ta, Si, and Fe were implanted under the same conditions as the ion-implanted metal of the comparative example.₂A concentration test in gas was performed. Table 2 summarizes the results.
[0073]
[Table 2]

[0074]
  As is clear from this result,MoneyEven if the metal ions are sprayed coatings (No. 1, 2), electroplating coatings (No. 3, 4), and PVD coatings (No. 5, 6), the surface of each coating has a concentration of injected metal. It can be seen that the fluorinated layer is clearly recognized and exhibits halogen gas resistance.
[0075]
On the other hand, in the film (Nos. 7 to 12) into which the metal ions of Comparative Example were implanted, no concentration phenomenon of the implanted metal was observed, and a metal fluoride having a high vapor pressure was generated. It can be seen that it has been converted to volatilization.
[0076]
<referenceExample 3>
  thisreferenceIn the example, a test piece of SUS304 steel and Al (JIS 4000, A1070) (20 mm × 30 mm × 3 mm) is used, and the surface thereof is ion-implanted and plasma ion-implanted.¹⁸/ Cm²CF after concentration injection₄And NF₃An exposure test at 300 ° C. for 24 hours in an atmosphere of 100 hPa was conducted to investigate the corrosion status of the metal ion implanted surface.
[0077]
  thisreferenceIn the example, as a comparative example, untreated SUS304 stainless steel, Al (A1070) and Ti and Ta metal ion-implanted test pieces were exposed under the same conditions. Table 3 shows the results.
[0078]
[Table 3]

[0079]
In this exposure test, untreated SUS304 steel (No. 17) produced a large amount of red powdered corrosion products, and untreated Al (No. 18) did not show large corrosion marks, but the surface was It had a satin-like corrosion form. Further, in the specimens (No. 9 to 16) into which Ti and Ta were injected, not only when the base material was SUS304 steel (No. 9 to 12) but also when the base material was an Al base material (No. 13 to 16). The formation of large corrosion marks was observed due to the corrosive action of the chemical gas.
[0080]
  On the other hand, CaIn the test piece into which Mg metal ions were implanted, the appearance was completely corrosive both when the base material was SUS304 steel (No. 1 to 4) and when the base material was Al base material (No. 5 to 8). Occurrence was not observed. In addition, Ca and Mg metal ions were implanted with almost the same anticorrosion effect by either the ion implantation method or the plasma ion implantation method.
[0081]
<Example1>
  In this example, SUS304 stainless steel specimens were used to investigate the halogen gas resistance when metal ions belonging to the present invention were laminated and implanted by plasma ion implantation. That is, Al is 1 × 10 as the primary injection to the substrate.¹²/ Cm²After injecting the concentration, 1 × 10 Mg was added thereon.¹²/ Cm²After concentration injection or Al / Mg layer injection, the injection energy was further reduced to form a thin film of Al and 50% Al-50% Mg alloy. This product has a halogen gas resistance of F₂, NF₃For 24 hours in a 100 hPa, 300 ° C. atmosphere. The results are as shown in Table 4.
[0082]
[Table 4]

[0083]
  Of this reference exampleIt has been found that metal ions exhibit halogen gas resistance even if they are layered or thinned.
[0084]
<Reference example 4>
  thisreferenceIn the examplereferenceThe same SUS316 steel test piece as in Example 1 was used, and 1 × 10 5 metal ions of 50Al-50Mg, Mg, Ba, Ca and Y were added thereto by plasma ion implantation.¹⁸/ Cm²After the implantation, the F-containing F₂Exposure to a gas atmosphere for 10 hours. In this exposure test chamber, an 8-inch diameter silicon wafer was allowed to stand, and the number of particle particles (environmental contamination particles) adhering to the wafer surface after 10 hours was observed and recorded using a magnifying glass. The particle diameter that can be observed and recorded with a magnifying glass was approximately 0.2 μm or more.
[0085]
The configuration of the test environment is as follows.
(1) Atmospheric gas: CF_Four/ Ar / O₂The mixing ratio is 100/100/10 cm in volume ratio^Three, Gas pressure 100Pa, temperature 60 ° C
(2) Plasma irradiation output: high frequency power: 1300 w × 10 hours
In addition, in this test, in addition to untreated SUS316 steel and anodized (alumite) Al as a comparative example, 1 × 10 Ti and Nb metal ions were added to SUS316 steel by plasma ion implantation.¹⁸/ Cm²The injected was tested under the same conditions. Table 5 summarizes the above test results.
[0086]
[Table 5]

[0087]
As is clear from this result, the test specimens (Nos. 6 to 9) of the comparative examples clearly show that after exposure for 10 hours, 100 or more particle particles adhere to the surface of the silicon wafer and become a source of environmental pollution. It became. When the components of these particle particles are investigated, Fe, Cr, Ni fluorides in the case of stainless steel specimens, and Al and F as main components in the case of Al bases, CF in the atmosphere_FourWas found to be a corrosion product induced by. In the test pieces (Nos. 6 and 7) into which Ti and Nb were injected, a large amount of Ti and Nb fluoride particles were observed, and it was confirmed that the corrosion resistance was poor in a halogen gas atmosphere to which plasma was added.
[0088]
  On the other hand, TrySpecimens (Nos. 1 to 5) were found to have excellent halogen environment resistance, with the number of particles adhering to the silicon wafer surface being 30 or less, even after a 10-hour exposure test. It was.
[0089]
【The invention's effect】
  As described in detail above, the surface of a metal substrate is subjected to ion implantation or plasma ion implantation.Ba,One or more selected from Mg and YGoldImplant metal ionsAnd form a thin filmDepending on halogen gas resistance, especially F₂Chemical resistance to gas and fluoride gas is significantly improved.
[0090]
  Injected into the substrate surface by the method of the present invention.Ba,Metals such as Mg and Y are F₂In an environment containing gas, each metal exhibits excellent halogen gas resistance by forming a fluoride layer having a low vapor pressure.
[0091]
The metal ion implantation mechanism and halogen gas resistance described above can minimize the contamination of the semiconductor processing environment by reducing the corrosion products of the device members in addition to extending the life of the semiconductor processing device members. Can be expected to contribute greatly to the improvement of product reliability and productivity.
[0092]
In addition, when the metal ion implantation layer has a maximum thickness of about 300 nm, it does not affect the shape and size of a precision machined semiconductor processing apparatus member.
[0093]
Further, in the case of metal ion implantation by the plasma ion implantation method, even if the object to be processed has a three-dimensional structure, it can be implanted uniformly and a plurality of metal ions can be simultaneously implanted. Injection is also easy.
[Brief description of the drawings]
FIG. 1 is a schematic view of a metal ion implantation apparatus.
FIG. 2 is a schematic view of a plasma ion implantation apparatus.
FIG. 3 is a view showing a cross section of the surface of an object to be processed on which metal ion implantation processing according to the present invention has been performed.
[Explanation of symbols]
    1 Ion source gas inlet
    2 Ion generation chamber
    3 Accelerator
    4 Mass separator
    5 Beam scanning system
    6 Target sample (object to be processed)
    21 Metal processing container
    22 Object to be processed
    23 DC power supply
    24 Gas phase ion source
    25 Metal-based ion source
    26 Outside the vacuum pump
    27 Pressure adjustment valve
    28 Plasma containing metal ions
    31 Object
    32 Metal ion implantation layer
    33 Metal thin film
    34 Metal spray coatingOf the part not ion-implanted

Claims (2)

On the surface of the metal substrate, by an ion implantation method or a plasma ion implantation method, Ba, Mg, after providing the metal ion-implanted layer by implanting one or more metal ions selected from Y, further thereon by plasma ion implantation method, Al, Ca, method for producing a resistant halogen gas of semiconductor processing equipment for members, characterized in that to 1~30μm laminating a thin film layer containing Mg or al least one metal selected. On the surface of the metal substrate, by an ion implantation method or a plasma ion implantation method, Ba, Mg, after providing the metal ion-implanted layer by implanting one or more metal ions selected from Y, further thereon by plasma ion implantation method, after laminating Al, Ca, a thin film layer containing Mg or al least one metal selected, 200 ° C. to 750 ° C., and performing heat treatment of 0.5 to 5 hours A method for producing a halogen processing gas-resistant member for a semiconductor processing apparatus .

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