JP2010080949A - Copper film annealing method, annealed copper film, and device having copper wiring - Google Patents

Copper film annealing method, annealed copper film, and device having copper wiring Download PDF

Info

Publication number
JP2010080949A
JP2010080949A JP2009196372A JP2009196372A JP2010080949A JP 2010080949 A JP2010080949 A JP 2010080949A JP 2009196372 A JP2009196372 A JP 2009196372A JP 2009196372 A JP2009196372 A JP 2009196372A JP 2010080949 A JP2010080949 A JP 2010080949A
Authority
JP
Japan
Prior art keywords
copper
wiring
annealing
copper film
plating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2009196372A
Other languages
Japanese (ja)
Inventor
Shigeru Yomogida
茂 蓬田
Takashi Yada
隆司 矢田
Akiko Hashimoto
亜紀子 橋本
Kazuyoshi Ueno
和良 上野
Yushi Shimada
裕至 島田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shibaura Institute of Technology
Kisco Ltd
Original Assignee
Shibaura Institute of Technology
Kisco Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shibaura Institute of Technology, Kisco Ltd filed Critical Shibaura Institute of Technology
Priority to JP2009196372A priority Critical patent/JP2010080949A/en
Publication of JP2010080949A publication Critical patent/JP2010080949A/en
Pending legal-status Critical Current

Links

Landscapes

  • Electrodes Of Semiconductors (AREA)
  • Internal Circuitry In Semiconductor Integrated Circuit Devices (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper film annealing method which can improve reliability of copper wiring by reducing an electric resistance of copper wiring, stabilizing it, and removing an impurity. <P>SOLUTION: The copper film is formed on a silicon substrate with a barrier layer formed by a plating method or a vapor deposition method. The copper film is treated in a gas of carbon dioxide at 200°C-300°C, 2-30 MPa, or in a gas of an inert element, or in a super-critical carbon dioxide, or in a gas or fluid of the above gas containing hydrogen. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、半導体装置の製造における銅配線膜形成工程に関するものであり、銅配線の電気抵抗低減および安定化技術に関するものである。   The present invention relates to a copper wiring film forming process in the manufacture of a semiconductor device, and relates to a technique for reducing and stabilizing electrical resistance of copper wiring.

従来のLSIやULSI等に代表される半導体装置における配線や電極の材料としては、主としてアルミニウム(Al)やその合金などが用いられている。しかし、近年の集積度の向上による微細化の進展や、動作スピードの向上等により、配線材料としてCu(銅)が多く使用されるようになっている。CuはAlよりも抵抗が低く、かつエレクトロマイグレーションやストレスマイグレーションいう配線を構成する金属原子の拡散挙動が支配する現象に対して、高い耐性を有する。   As materials for wiring and electrodes in semiconductor devices represented by conventional LSIs and ULSIs, aluminum (Al) and alloys thereof are mainly used. However, Cu (copper) is often used as a wiring material due to the progress of miniaturization due to the recent improvement in integration degree and the improvement of operation speed. Cu has a lower resistance than Al, and has high resistance to a phenomenon in which the diffusion behavior of metal atoms constituting wirings such as electromigration and stress migration dominates.

さらに、液晶表示装置等の表示装置の分野においても、表示面積の拡大による配線長の増加や、駆動用ドライバ回路や画素内メモリといった様々な付加機能を搭載するモノリシック化や、大容量・大画面・高精細化等の要求により半導体分野と同様に低抵抗な配線が要求されている。このため、これらの分野においても銅配線の重要性が増している。   Furthermore, in the field of display devices such as liquid crystal display devices, the wiring length increases due to the expansion of the display area, monolithic mounting with various additional functions such as a driver circuit for driving and in-pixel memory, and a large capacity and large screen.・ Low resistance wiring is required in the same manner as in the semiconductor field due to demands for higher definition. For this reason, the importance of copper wiring is also increasing in these fields.

ところで、銅の微細な配線加工は、Al配線と同様なフォトリソグラフィー等のマスキング技術と、RIE(Reactive Ion Etching:反応性イオンエッチング)等のエッチング技術とを単に組み合わせただけでは実現が困難である。銅のハロゲン化物の蒸気圧は、Alに対して非常に低く、蒸発しにくいため、RIE等のエッチング技術を用いる場合には、プロセス温度として200〜300℃の雰囲気下での処理が必要である等、種々の問題が多い。また、通常のフォトレジストマスクではなく、SiO2 やSiNx によるマスクを使用する必要もある。 By the way, copper fine wiring processing is difficult to realize by simply combining a masking technique such as photolithography similar to the Al wiring and an etching technique such as RIE (Reactive Ion Etching). . Since the vapor pressure of copper halide is very low with respect to Al and is difficult to evaporate, when an etching technique such as RIE is used, treatment under an atmosphere at a process temperature of 200 to 300 ° C. is necessary. There are many various problems. Further, it is necessary to use a mask made of SiO 2 or SiN x instead of a normal photoresist mask.

銅の配線加工技術として代表的なものは、例えば特許文献1や特許文献2に開示されているダマシン法である。このダマシン法による銅配線の形成は、次のような工程を経て行われる。まず、基板上の絶縁層に対して、予め所望の配線パターンの配線溝を形成する。次に、銅の酸化シリコン層中への拡散を防止するために銅薄層の下地層としてTaN、Ta、TiN、等の銅拡散防止層を形成する。次いで、この銅拡散防止層上に銅薄層を形成する。この銅薄層は、配線溝を埋め込むようにスパッタリング法等のPVD(PHYSICAL VAPOR DEPOSITION)法、めっき法または、有機金属材料を用いたCVD(CHEMICAL VAPOR DEPOSITION:化学気相成長)法等の種々の手法を用いて、溝内部に埋め込み、かつ絶縁層上の全面にわたって形成する。その後、銅薄層を基板表面側から下層の絶縁層が露出する(溝部分の開口端面)までCMP(CHEMICAL MECHANICAL POLISING:化学的機械研磨法)等の研磨法やエッチバック等を用いて除去し、溝に埋め込まれた銅のみによる配線パターンを形成する。さらに、銅配線上に銅拡散防止能を有する絶縁層もしくは金属層を形成して銅配線層を覆う。   A typical example of the copper wiring processing technique is the damascene method disclosed in Patent Document 1 and Patent Document 2, for example. The formation of copper wiring by this damascene method is performed through the following steps. First, a wiring groove having a desired wiring pattern is formed in advance on the insulating layer on the substrate. Next, in order to prevent the diffusion of copper into the silicon oxide layer, a copper diffusion preventing layer such as TaN, Ta, TiN or the like is formed as an underlayer of the copper thin layer. Next, a thin copper layer is formed on the copper diffusion prevention layer. This copper thin layer is formed by various methods such as PVD (PHYSICAL VAPOR DEPOSITION) method such as sputtering method, plating method or CVD (CHEMICAL VAPOR DEPOSITION) method using organic metal material so as to fill the wiring groove. Using a technique, it is embedded in the groove and formed over the entire surface of the insulating layer. After that, the copper thin layer is removed using a polishing method such as CMP (CHEMICAL MECHANICAL POLISING) or etch back until the underlying insulating layer is exposed from the substrate surface side (open end face of the groove). Then, a wiring pattern made only of copper embedded in the groove is formed. Further, an insulating layer or a metal layer having a copper diffusion preventing ability is formed on the copper wiring to cover the copper wiring layer.

また、配線および接続孔の凹部パターンヘの銅による埋め込みについては、コストのかからない技術として電解銅めっき法による銅の埋め込みが広く採用されているが、予め、電極として拡散バリア用下地膜上にCuシード膜と呼ばれる第1の銅膜を形成しておく必要がある。   In addition, for copper embedding in the recess pattern of wiring and connection holes, copper embedding by electrolytic copper plating is widely adopted as a cost-effective technique, but Cu seeds are previously formed on the diffusion barrier underlayer as electrodes. It is necessary to form a first copper film called a film.

ところで、めっき法あるいはスパッタリング法で成膜された直後の銅膜は、結晶が不均一、不安定で抵抗値も高い。このため、例えば特開2003−328184号公報(特許文献3)に記載されているような熱アニール処理が行われている。すなわち、不活性ガス中で高温処理(アニール)することによって銅が結晶化され、安定化し、抵抗値が減少する。   By the way, the copper film immediately after being formed by the plating method or the sputtering method has nonuniform and unstable crystals and a high resistance value. For this reason, for example, a thermal annealing process as described in JP 2003-328184 A (Patent Document 3) is performed. That is, copper is crystallized and stabilized by high-temperature treatment (annealing) in an inert gas, and the resistance value decreases.

大気圧中で不活性ガスによりアニールし、安定化された通常の銅配線は結晶化した銅の粒子が積層−配列しているが、粒子が依然として小さく、また粒子間の界面(粒界)が多く存在しているため、単結晶の銅よりも高い比抵抗値を持つ。さらに、粒界を多く持つ従来の銅配線は、ストレスマイグレーション(SM)やエレク卜ロマイグレーシコン(EM)を起こし易く、これによりボイドが発生して抵抗値上昇や断線を引き起こしている。   Normal copper wiring that has been stabilized by annealing with an inert gas at atmospheric pressure has crystallized copper particles stacked and arranged, but the particles are still small and the interface (grain boundary) between the particles is small. Because there are many, it has a specific resistance value higher than that of single crystal copper. Furthermore, the conventional copper wiring having many grain boundaries is liable to cause stress migration (SM) and electrochromic silicon (EM), which causes voids and causes an increase in resistance value and disconnection.

半導体装置の微細化、高速化、低電力化が進み、比抵抗値のより低い銅が配線材として導入されたが、さらなる微細化が求められ、より安定した信頼性の高い銅配線が求められている。回路配線の微細化が進んで銅配線膜の断面積が減ることにより抵抗が増し、さらにSMまたはEMに対する耐性が低下するため、より粒子の結晶化、巨大化した銅配線膜が求められている。   As semiconductor devices have been miniaturized, speeded up and reduced in power consumption, copper having a lower specific resistance value has been introduced as a wiring material. However, further miniaturization is required and more stable and reliable copper wiring is required. ing. As the circuit wiring becomes finer and the cross-sectional area of the copper wiring film decreases, the resistance increases and the resistance to SM or EM decreases. Therefore, there is a need for a copper wiring film that is more crystallized and enlarged. .

一方、めっき時には均一にめっきを行うことなどを目的とした添加剤等がめっき液中に含まれており、これらが配線膜やデバイス構成材料中取り込まれる。特にめっき時に膜中に取り込まれた活性剤などの不純物や、多層配線形成におけるアッシング、エッチング工程によって、膜中に侵入、汚染した酸素やフッ素等の不純物は結果として配線膜の比抵抗値を上昇させ、さらには信頼性を低下させている。
特開2001−189295公報 特開平11−135504号公報 特開2003−328184号公報
On the other hand, an additive for the purpose of uniformly plating at the time of plating is included in the plating solution, and these are taken into the wiring film and the device constituent material. In particular, impurities such as activator incorporated in the film during plating, and impurities such as oxygen and fluorine that have entered and contaminated the film due to ashing and etching processes in the formation of multilayer wiring result in an increase in the specific resistance of the wiring film. Furthermore, the reliability is lowered.
JP 2001-189295 A Japanese Patent Laid-Open No. 11-135504 JP 2003-328184 A

本発明の目的は、銅配線の電気抵抗低減および安定化を実現し、銅配線の信頼性を向上させることが可能な銅膜のアニール方法、アニールされた銅配線およびこの銅配線を有するデバイスを提供することである。また、配線構造を形成する過程で配線あるいはデバイス構成材料中に取り込まれた不純物を除去し、配線膜の比抵抗値の上昇を防止し、信頼性を高めることのできるアニール方法、アニールされた配線およびこの配線を有するデバイスを提供することである。   An object of the present invention is to provide a copper film annealing method, an annealed copper wiring, and a device having the copper wiring capable of reducing and stabilizing the electrical resistance of the copper wiring and improving the reliability of the copper wiring. Is to provide. Also, an annealing method and an annealed wiring that can remove the impurities incorporated in the wiring or device constituent material in the process of forming the wiring structure, prevent an increase in the specific resistance value of the wiring film, and improve the reliability. And providing a device having this wiring.

半導体集積回路用銅配線の特に100nm以下の微細化に伴い、電子散乱効果による配線抵抗(比抵抗)の増加が顕著になってきた。電子散乱効果の原因は、粒界散乱と側面散乱であり、粒径の拡大が電子散乱効果を減らすのに有効であると考えられる。めっき法あるいはスバッタリング法で成膜された直後の銅膜は、結晶が不均一、不安定で抵抗値も高い。   With the miniaturization of copper wiring for semiconductor integrated circuits, particularly 100 nm or less, the increase in wiring resistance (specific resistance) due to the electron scattering effect has become remarkable. The cause of the electron scattering effect is grain boundary scattering and side scattering, and it is considered that the increase in particle size is effective in reducing the electron scattering effect. The copper film immediately after being formed by the plating method or the sputtering method has nonuniform and unstable crystals and a high resistance value.

不活性ガス中で高温処理(アニール)することによって銅が結晶化され、安定化し、抵抗値が減少する。熱アニールは、少なくともアニール条件を選定することで結晶粒構造をコントロールして電解めっき後の結晶粒成長を高めるために一般的に採用されてきた。このアニールは、例えば銅めっき後の基板を、100から500℃程度、好ましくは150から400℃程度の温度に保持することにより行われる。   Copper is crystallized and stabilized by high-temperature treatment (annealing) in an inert gas, and the resistance value decreases. Thermal annealing has been generally employed to control crystal grain structure by at least selecting annealing conditions to enhance crystal grain growth after electrolytic plating. This annealing is performed, for example, by maintaining the substrate after copper plating at a temperature of about 100 to 500 ° C., preferably about 150 to 400 ° C.

しかし、前記微細化等に伴い熱アニールだけでは不十分である。また、めっき時には均一にめっきを行うことなどを目的とした添加剤等がめっき液中に含まれており、これらが配線膜中取り込まれる。このような不純物も配線膜の比抵抗を上昇させる要因となるため、不純物を極力除去する必要がる。このため、本発明者らはさらに粒径の拡大等、低抵抗化に繋がる新たなアニール方法の検討を行った。   However, thermal annealing alone is not sufficient with the miniaturization. Further, an additive for the purpose of uniformly plating at the time of plating is contained in the plating solution, and these are taken into the wiring film. Since such impurities also cause an increase in the specific resistance of the wiring film, it is necessary to remove the impurities as much as possible. For this reason, the present inventors further studied a new annealing method that leads to a reduction in resistance, such as an increase in particle diameter.

すなわち上記の目的は、以下の本発明の構成により解決される。
(1) 半導体ウエハー上にめっき法あるいは気相堆積法により形成された銅膜を常温、常圧より高温、高圧の二酸化炭素または不活性元素の気体ないし流体中で処理する銅膜のアニール方法。
(2) 前記高温、高圧は、200〜400℃、2〜30MPaである上記(1)の銅膜のアニール方法。
(3) 前記二酸化炭素または不活性元素の気体ないし流体中に、さらに0.01質量%以上の水素を含有する上記(1)または(2)の銅膜のアニール方法。
(4) 前記銅膜中の平均結晶粒径を増大させる上記(1)〜(3)のいずれかの銅膜のアニール方法。
(5) 前記銅膜の表面もしくは膜中の不純物を除去あるいは減少させる上記(1)〜(4)のいずれかの銅膜のアニール方法。
(6) 上記(1)〜(5)のいずれかの方法により処理されたアニールされた銅配線。
(7) 上記(6)のアニールされた銅配線を有するデバイス。
That is, the above object is solved by the following configuration of the present invention.
(1) A copper film annealing method in which a copper film formed by plating or vapor deposition on a semiconductor wafer is treated in carbon dioxide or an inert element gas or fluid at normal temperature, higher than normal pressure, or high pressure.
(2) The method for annealing a copper film according to (1), wherein the high temperature and high pressure are 200 to 400 ° C. and 2 to 30 MPa.
(3) The method for annealing a copper film according to (1) or (2) above, wherein 0.01% by mass or more of hydrogen is further contained in the gas or fluid of carbon dioxide or an inert element.
(4) The method for annealing a copper film according to any one of (1) to (3), wherein the average crystal grain size in the copper film is increased.
(5) The method for annealing a copper film according to any one of (1) to (4), wherein impurities on the surface of the copper film or in the film are removed or reduced.
(6) An annealed copper wiring treated by any one of the methods (1) to (5).
(7) A device having the annealed copper wiring of (6) above.

本発明によれば、銅配線の電気抵抗低減および安定化実現し、銅配線の信頼性を向上させることが可能な銅膜のアニール方法、アニールされた銅配線およびこの銅配線を有するデバイスを提供することができる。   According to the present invention, a copper film annealing method, an annealed copper wiring, and a device having the copper wiring capable of reducing and stabilizing the electrical resistance of the copper wiring and improving the reliability of the copper wiring are provided. can do.

アニールを行う前のサンプルの結晶構造を示すFIB−SIM図面代用写真である。It is a FIB-SIM drawing substitute photograph which shows the crystal structure of the sample before performing annealing. CO2 雰囲気下でのアニールを行ったサンプルの結晶構造を示すFIB−SIM図面代用写真である。CO is a FIB-SIM drawing-substitute photograph showing a crystal structure of a sample annealed under 2 atmosphere. CO2 +H2 雰囲気下でのアニールを行ったサンプルの結晶構造を示すFIB−SIM図面代用写真である。CO 2 + H is a FIB-SIM drawing-substitute photograph showing a crystal structure of a sample annealed under 2 atmosphere. 常圧N2 雰囲気でのアニールを行ったサンプルの結晶構造を示すFIB−SIM図面代用写真である。Is a FIB-SIM drawing-substitute photograph showing a crystal structure of a sample annealed at atmospheric pressure N 2 atmosphere.

本発明の銅膜のアニール方法は、半導体ウエハー上にめっき法あるいは気相堆積法により形成された銅膜を常温、常圧より高温、高圧の二酸化炭素または不活性の気体ないし流体中で処理するものである。   In the copper film annealing method of the present invention, a copper film formed on a semiconductor wafer by plating or vapor deposition is processed at room temperature, higher than normal pressure, high pressure carbon dioxide, or an inert gas or fluid. Is.

このように、二酸化炭素、アルゴンなどの不活性元素のガス・流体、特に二酸化炭素ガス・流体雰囲気中で加熱加圧してアニール処理することで、銅膜中の結晶粒径が増大し、粒界中の不純物が減少する。このため、電子散乱効果が減少し、配線の比抵抗(=抵抗率)ρが減少する。また、配線膜表面や膜中の不純物、特に銅の結晶粒界の不純物が減少し、配線の信頼性が増大するとともに、比抵抗も減少する。   In this way, annealing and heating in a gas / fluid of inert elements such as carbon dioxide and argon, especially carbon dioxide gas / fluid atmosphere, the crystal grain size in the copper film increases, and the grain boundary Impurities in it are reduced. For this reason, the electron scattering effect is reduced, and the specific resistance (= resistivity) ρ of the wiring is reduced. Further, impurities on the surface of the wiring film and in the film, particularly impurities at the crystal grain boundaries of copper are reduced, and the reliability of the wiring is increased and the specific resistance is also reduced.

本発明の銅膜は、半導体ウエハー上にめっき法あるいは気相堆積法により形成される。めっき法は、この種の配線膜形成に用いられている一般的なめっき方法であれば特に限定されるものではなく、電解めっきでも無電解めっきでもよい。また、気相体積法も銅配線膜形成が可能なものであれば特に限定されるものではなく、スパッタリング法等のPVD(PHYSICAL VAPOR DEPOSITION)法、有機金属材料を用いたCVD(CHEMICAL VAPOR DEPOSITION:化学気相成長)法、その他の気相体積法を用いることができる。これらの中でも、特に膜の密着性等の観点からめっき法が好ましい。具体的な銅配線の形成方法は、多くの半導体関連の文献に記載されているのでそれらを参照されたい。   The copper film of the present invention is formed on a semiconductor wafer by plating or vapor deposition. The plating method is not particularly limited as long as it is a general plating method used for this type of wiring film formation, and may be electrolytic plating or electroless plating. The vapor volume method is not particularly limited as long as the copper wiring film can be formed. PVD (PHYSICAL VAPOR DEPOSITION) method such as sputtering method, CVD (CHEMICAL VAPOR DEPOSITION): Chemical vapor deposition) and other vapor volume methods can be used. Among these, the plating method is particularly preferable from the viewpoint of film adhesion and the like. Specific methods for forming copper wiring are described in many semiconductor-related documents, so please refer to them.

アニールの雰囲気は、二酸化炭素、アルゴンなどの不活性元素のガス・流体である。ここで不活性元素とは、周期表第18族の元素であり、具体的にはヘリウムHe、ネオンNe、アルゴンAr、クリプトンKr、キセノンXe、ラドンRnである。これらの中でも、ヘリウムHe、ネオンNe、アルゴンArが好ましい。また、アニール雰囲気は特に二酸化炭素が好ましい。これらの二酸化炭素あるいは元素は、気体でも液体でも、それらの中間的な状態でもよい。また、いわゆる超臨界状態となっていると特に好ましい結果が得られ、亜臨界状態が次いでよい。   The annealing atmosphere is a gas / fluid of an inert element such as carbon dioxide or argon. Here, the inert element is an element belonging to Group 18 of the periodic table, and specifically helium He, neon Ne, argon Ar, krypton Kr, xenon Xe, and radon Rn. Among these, helium He, neon Ne, and argon Ar are preferable. The annealing atmosphere is particularly preferably carbon dioxide. These carbon dioxide or elements may be gas, liquid, or an intermediate state thereof. In addition, a particularly preferable result is obtained when a so-called supercritical state is obtained, and a subcritical state is next preferred.

処理条件としては、処理温度は160℃以上、さらには200℃以上が好ましく、特に200〜400℃が好ましい。温度が低すぎるとアニール効果が薄れ、高すぎると半導体構造にダメージを与える恐れがある。処理時の圧力は、1.5MPa以上が好ましく、さらには2〜30MPaが好ましい、特に超臨界状態となる7.4MPa以上であることが好ましい。処理時間としては10min 以上、特に20min 以上、さらには30min 以上が好ましい。上限は特に限定されるものではないが、120min 以下、特に60min 以下が好ましい。また、30min 以下でも効果が得られる。   As processing conditions, the processing temperature is preferably 160 ° C. or higher, more preferably 200 ° C. or higher, and particularly preferably 200 to 400 ° C. If the temperature is too low, the annealing effect is reduced, and if it is too high, the semiconductor structure may be damaged. The pressure during the treatment is preferably 1.5 MPa or more, more preferably 2 to 30 MPa, and particularly preferably 7.4 MPa or more which is in a supercritical state. The treatment time is preferably 10 min or more, particularly 20 min or more, and more preferably 30 min or more. The upper limit is not particularly limited, but is preferably 120 min or less, particularly preferably 60 min or less. The effect can be obtained even at 30 min or less.

本発明のアニール処理は、上記のようにガス雰囲気中でも効果があるが、特に二酸化炭素を超臨界状態(31.1℃、7.4Mpa以上)にして行うことにより、より高い効果が得られる。また、いわゆる亜臨界状態であっても超臨界に準じた効果が得られる。   Although the annealing treatment of the present invention is effective even in a gas atmosphere as described above, a higher effect can be obtained particularly by performing carbon dioxide in a supercritical state (31.1 ° C., 7.4 MPa or more). Even in a so-called subcritical state, an effect equivalent to supercriticality can be obtained.

本発明のアニール方法では、上記二酸化炭素、不活性元素雰囲気下で優れた効果が得られるが、さらに水素を添加するとより効果的である。水素の添加量としては、前記に酸化炭素に対する割合で、好ましくは0.01質量%以上、より好ましくは0.04質量%以上、特に0.1質量%以上添加するとよい。水素を添加することで、さらに粒子の結晶化、巨大化を促進する。   In the annealing method of the present invention, an excellent effect can be obtained under the atmosphere of carbon dioxide and an inert element, but it is more effective when hydrogen is further added. The amount of hydrogen to be added is preferably 0.01% by mass or more, more preferably 0.04% by mass or more, and particularly preferably 0.1% by mass or more, in the above-described ratio relative to carbon oxide. Adding hydrogen further promotes crystallization and enlarging of particles.

本発明のアニール処理を行うことにより、従来の窒素雰囲気下での熱アニールと比較して格段に優れた効果を得ることができる。先ず、銅膜中の結晶粒径が増大ないし拡大し、粒界散乱に由来する電子散乱効果が減少して比抵抗が格段に減少する。具体的には、平均結晶粒径が好ましくは1μm 以上、さらには2μm 以上、特に、2.5μm 以上になる。この平均結晶粒径は、80%以上の結晶粒の平均粒径を平均化したものであることが望ましい。また、シート抵抗は窒素雰囲気下での熱アニールに比べ、好ましくは2%以上、さらには5%以上、特に7%以上減少する。   By carrying out the annealing treatment of the present invention, a markedly superior effect can be obtained as compared with the conventional thermal annealing in a nitrogen atmosphere. First, the crystal grain size in the copper film increases or expands, the electron scattering effect resulting from grain boundary scattering decreases, and the specific resistance decreases dramatically. Specifically, the average crystal grain size is preferably 1 μm or more, more preferably 2 μm or more, and particularly 2.5 μm or more. This average crystal grain size is desirably an average of the average grain sizes of 80% or more of crystal grains. Further, the sheet resistance is preferably reduced by 2% or more, more preferably 5% or more, and particularly 7% or more, as compared with thermal annealing in a nitrogen atmosphere.

上記のように本発明の銅配線は、めっき法により形成することが好ましい。めっき法により形成された銅膜に対して本発明のアニールはより効果的である。このようなめっき法による配線構造の形成は、従来微細回路パターンを有する基板の銅めっきに使用されてきた酸性銅めっきやアルカリ性銅めっきにより行うことができる。   As described above, the copper wiring of the present invention is preferably formed by a plating method. The annealing of the present invention is more effective for the copper film formed by plating. Formation of the wiring structure by such a plating method can be performed by acidic copper plating or alkaline copper plating that has been conventionally used for copper plating of a substrate having a fine circuit pattern.

この銅めっき浴の組成や、そのめっき条件も、従来から基板上の微細回路パターン(溝や孔)を埋め込むために用いられてきたものをそのまま利用することができ、例えば硫酸等のアニオン濃度が低いレベリング性の優れた組成を有するものが利用できる。   The composition of this copper plating bath and its plating conditions can be used as they are for embedding fine circuit patterns (grooves and holes) on the substrate as they are. Those having an excellent composition with low leveling properties can be used.

銅めっきとして好ましく用いられる酸性銅めっき浴について、以下にその組成および条件を例示する。
[電解めっき]
浴組成:硫酸銅150〜250g/L、硫酸10〜250g/L、塩素30〜90mg/L、有機添加剤1〜20mL/L
[めっき条件]
電流密度0.3〜5A/dm2 、めっき時間30秒〜5分、温度20〜30℃
About the acidic copper plating bath preferably used as copper plating, the composition and conditions are illustrated below.
[Electrolytic plating]
Bath composition: copper sulfate 150-250 g / L, sulfuric acid 10-250 g / L, chlorine 30-90 mg / L, organic additive 1-20 mL / L
[Plating conditions]
Current density 0.3-5A / dm 2 , plating time 30 seconds-5 minutes, temperature 20-30 ° C

上記の銅めっきにより微細回路パターンが埋め込まれた基板は、アニールされた後、CMPにより不要な銅めっき部分を除去し、基板上に銅による微細回路配線が形成される。なお、ここでは代表的な酸性銅めっきである硫酸銅めっき浴について示したが、ピロりん酸銅めっき浴等のアルカリ性銅めっき浴を用いてもよい。上記のような銅配線は、特に半導体集積回路用銅配線として優れている。   The substrate on which the fine circuit pattern is embedded by the copper plating is annealed, and then an unnecessary copper plating portion is removed by CMP to form a fine circuit wiring made of copper on the substrate. In addition, although it showed about the copper sulfate plating bath which is typical acid copper plating here, you may use alkaline copper plating baths, such as a pyrophosphate copper plating bath. The copper wiring as described above is particularly excellent as a copper wiring for a semiconductor integrated circuit.

SiO2 層200nmの酸化膜つきSi基板上に、TaNバリア層5nm/Taバリア層10nm/Cuシード層50nmをスパッタリング法にて堆積した後、電解めっきを用いてCu膜を500nm成膜した。その後、CO2 およびCO2 +H2 の超臨界流体によるアニールを行った。この時のアニール条件は、15MPa 、300℃、30min であった。また、比較サンプルとして常圧N2 雰囲気下でのアニールも行った。この時のアニール条件は、常圧、300℃、30min であった。アニール前後のシート抵抗変化を四探針法により測定した。また、FIB−SIM〔集束イオンビーム(FIB)/走査イオン顕微鏡(SIM)〕により、アニール前のサンプル、CO2 のみのアニールを行ったサンプル、CO2 +H2 のアニールを行ったサンプル、N2 雰囲気下でアニールを行ったサンプルの粒径の観察を行った。結果をそれぞれ図1〜4に示す。 A TaN barrier layer 5 nm / Ta barrier layer 10 nm / Cu seed layer 50 nm was deposited on a Si substrate with an SiO 2 layer 200 nm oxide film by a sputtering method, and then a Cu film was formed to 500 nm by electrolytic plating. Thereafter, annealing was performed with a supercritical fluid of CO 2 and CO 2 + H 2 . The annealing conditions at this time were 15 MPa, 300 ° C., and 30 min. In addition, annealing was performed under a normal pressure N 2 atmosphere as a comparative sample. The annealing conditions at this time were normal pressure, 300 ° C., and 30 min. The change in sheet resistance before and after annealing was measured by the four probe method. Further, the sample by FIB-SIM [focused ion beam (FIB) / scanning ion microscope (SIM)], was carried out before annealing of the sample, the sample was annealed for only CO 2, the annealing of the CO 2 + H 2, N 2 The particle size of the sample annealed in the atmosphere was observed. The results are shown in FIGS.

CO2 +H2 アニール後のシート抵抗は、常圧窒素雰囲気中で300℃のアニールを行った場合に比較して、約3%低減された。FIB−SIMによる粒構造を比較すると、図4に示すように、常圧N2 アニールの場合には、粒径にばらつきが見られ、形状がランダムである。これに対し。図2の超臨界アニール(CO2 )の場合は、ばらつきが少なく、揃った形状の粒構造が観察された。また、図3の水素を添加した方が、さらに揃った形状の粒構造で粒径が大きい傾向が見られた。これらの結果から、CO2 、またはCO2 +H2 アニールによって、図1の常圧とは異なる粒構造が得られ、粒径の増大と均一化が図れることがわかる。また、特にCO2 +H2 でのアニールが効果的であることがわかる。 The sheet resistance after the CO 2 + H 2 annealing was reduced by about 3% as compared with the case where the annealing at 300 ° C. was performed in a normal pressure nitrogen atmosphere. Comparing the grain structure by FIB-SIM, as shown in FIG. 4, in the case of normal pressure N 2 annealing, the grain size varies and the shape is random. On the other hand. In the case of supercritical annealing (CO 2 ) in FIG. 2, there was little variation and a uniform grain structure was observed. Moreover, the direction which added the hydrogen of FIG. 3 had the tendency for a particle size to be large with the grain structure of the more uniform shape. These results, CO 2, or by CO 2 + H 2 anneal, normal pressure different particle structures can be obtained from the in FIG. 1, it can be seen that attained is increased and uniform particle size. It can also be seen that annealing with CO 2 + H 2 is particularly effective.

本発明は、IC,LSI 等の半導体装置の製造における銅配線膜形成工程において、銅配線の電気抵抗低減および安定化図る上で極めて有用である。また、半導体のみならず、微細配線構造を有するデバイス、構造体等、種々の銅配線を有する構造に有効である。   INDUSTRIAL APPLICABILITY The present invention is extremely useful for reducing and stabilizing the electrical resistance of copper wiring in a copper wiring film forming process in the manufacture of semiconductor devices such as ICs and LSIs. Further, it is effective not only for semiconductors but also for structures having various copper wirings such as devices and structures having a fine wiring structure.

Claims (7)

半導体ウエハー上にめっき法あるいは気相堆積法により形成された銅膜を常温、常圧より高温、高圧の二酸化炭素または不活性元素の気体ないし流体中で処理する銅膜のアニール方法。 A copper film annealing method in which a copper film formed by plating or vapor deposition on a semiconductor wafer is treated in a carbon dioxide or inert element gas or fluid at normal temperature, higher than normal pressure, or high pressure. 前記高温、高圧は、200〜400℃、2〜30MPaである請求項1の銅膜のアニール方法。 The method for annealing a copper film according to claim 1, wherein the high temperature and high pressure are 200 to 400 ° C. and 2 to 30 MPa. 前記二酸化炭素または不活性元素の気体ないし流体中に、さらに0.01質量%以上の水素を含有する請求項1または2の銅膜のアニール方法。 The method for annealing a copper film according to claim 1 or 2, further comprising 0.01 mass% or more of hydrogen in the gas or fluid of carbon dioxide or an inert element. 前記銅膜中の平均結晶粒径を増大させる請求項1〜3のいずれかの銅膜のアニール方法。 The method for annealing a copper film according to claim 1, wherein an average crystal grain size in the copper film is increased. 前記銅膜の表面もしくは膜中の不純物を除去あるいは減少させる請求項1〜4のいずれかの銅膜のアニール方法。 The method for annealing a copper film according to claim 1, wherein impurities on the surface of the copper film or in the film are removed or reduced. 請求項1〜5のいずれかの方法により処理されたアニールされた銅配線。 An annealed copper wiring treated by the method of any of claims 1-5. 請求項6のアニールされた銅配線を有するデバイス。 7. A device having the annealed copper wiring of claim 6.
JP2009196372A 2008-08-29 2009-08-27 Copper film annealing method, annealed copper film, and device having copper wiring Pending JP2010080949A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2009196372A JP2010080949A (en) 2008-08-29 2009-08-27 Copper film annealing method, annealed copper film, and device having copper wiring

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2008221527 2008-08-29
JP2009196372A JP2010080949A (en) 2008-08-29 2009-08-27 Copper film annealing method, annealed copper film, and device having copper wiring

Publications (1)

Publication Number Publication Date
JP2010080949A true JP2010080949A (en) 2010-04-08

Family

ID=42210970

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2009196372A Pending JP2010080949A (en) 2008-08-29 2009-08-27 Copper film annealing method, annealed copper film, and device having copper wiring

Country Status (1)

Country Link
JP (1) JP2010080949A (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017213835A1 (en) 2016-06-10 2017-12-14 Applied Materials, Inc. Seam-healing method upon supra-atmospheric process in diffusion promoting ambient
CN114420787A (en) * 2021-12-22 2022-04-29 西安隆基乐叶光伏科技有限公司 Annealing method and annealing equipment for solar cell
US11361978B2 (en) 2018-07-25 2022-06-14 Applied Materials, Inc. Gas delivery module
US11462417B2 (en) 2017-08-18 2022-10-04 Applied Materials, Inc. High pressure and high temperature anneal chamber
US11527421B2 (en) 2017-11-11 2022-12-13 Micromaterials, LLC Gas delivery system for high pressure processing chamber
US11581183B2 (en) 2018-05-08 2023-02-14 Applied Materials, Inc. Methods of forming amorphous carbon hard mask layers and hard mask layers formed therefrom
US11610773B2 (en) 2017-11-17 2023-03-21 Applied Materials, Inc. Condenser system for high pressure processing system
US11694912B2 (en) 2017-08-18 2023-07-04 Applied Materials, Inc. High pressure and high temperature anneal chamber
US11705337B2 (en) 2017-05-25 2023-07-18 Applied Materials, Inc. Tungsten defluorination by high pressure treatment
US11749555B2 (en) 2018-12-07 2023-09-05 Applied Materials, Inc. Semiconductor processing system
US11881411B2 (en) 2018-03-09 2024-01-23 Applied Materials, Inc. High pressure annealing process for metal containing materials
US11901222B2 (en) 2020-02-17 2024-02-13 Applied Materials, Inc. Multi-step process for flowable gap-fill film

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017213835A1 (en) 2016-06-10 2017-12-14 Applied Materials, Inc. Seam-healing method upon supra-atmospheric process in diffusion promoting ambient
KR20190006095A (en) * 2016-06-10 2019-01-16 어플라이드 머티어리얼스, 인코포레이티드 Seam during the super-atmospheric process in a diffusion-promoting atmosphere - healing method
JP2019517740A (en) * 2016-06-10 2019-06-24 アプライド マテリアルズ インコーポレイテッドApplied Materials,Incorporated Seam remediation in a superatmosphere process in a diffusion promoting atmosphere
EP3469626A4 (en) * 2016-06-10 2020-02-19 Applied Materials, Inc. Seam-healing method upon supra-atmospheric process in diffusion promoting ambient
US10636704B2 (en) 2016-06-10 2020-04-28 Applied Materials, Inc. Seam-healing method upon supra-atmospheric process in diffusion promoting ambient
JP2020174182A (en) * 2016-06-10 2020-10-22 アプライド マテリアルズ インコーポレイテッドApplied Materials,Incorporated Seam repair method in super atmospheric process in diffusion-promoting atmosphere
KR102182127B1 (en) * 2016-06-10 2020-11-23 어플라이드 머티어리얼스, 인코포레이티드 Seam-healing method in the hyper-atmospheric process in a diffusion-promoting atmosphere
US11705337B2 (en) 2017-05-25 2023-07-18 Applied Materials, Inc. Tungsten defluorination by high pressure treatment
US11469113B2 (en) 2017-08-18 2022-10-11 Applied Materials, Inc. High pressure and high temperature anneal chamber
US11462417B2 (en) 2017-08-18 2022-10-04 Applied Materials, Inc. High pressure and high temperature anneal chamber
US11694912B2 (en) 2017-08-18 2023-07-04 Applied Materials, Inc. High pressure and high temperature anneal chamber
US11527421B2 (en) 2017-11-11 2022-12-13 Micromaterials, LLC Gas delivery system for high pressure processing chamber
US11756803B2 (en) 2017-11-11 2023-09-12 Applied Materials, Inc. Gas delivery system for high pressure processing chamber
US11610773B2 (en) 2017-11-17 2023-03-21 Applied Materials, Inc. Condenser system for high pressure processing system
US11881411B2 (en) 2018-03-09 2024-01-23 Applied Materials, Inc. High pressure annealing process for metal containing materials
US11581183B2 (en) 2018-05-08 2023-02-14 Applied Materials, Inc. Methods of forming amorphous carbon hard mask layers and hard mask layers formed therefrom
US11361978B2 (en) 2018-07-25 2022-06-14 Applied Materials, Inc. Gas delivery module
US11749555B2 (en) 2018-12-07 2023-09-05 Applied Materials, Inc. Semiconductor processing system
US11901222B2 (en) 2020-02-17 2024-02-13 Applied Materials, Inc. Multi-step process for flowable gap-fill film
WO2023115808A1 (en) * 2021-12-22 2023-06-29 西安隆基乐叶光伏科技有限公司 Annealing method and annealing apparatus for solar cell
CN114420787A (en) * 2021-12-22 2022-04-29 西安隆基乐叶光伏科技有限公司 Annealing method and annealing equipment for solar cell

Similar Documents

Publication Publication Date Title
JP2010080949A (en) Copper film annealing method, annealed copper film, and device having copper wiring
US7741214B2 (en) Method of forming a semiconductor device featuring copper wiring layers of different widths having metal capping layers of different thicknesses formed thereon
US6607982B1 (en) High magnesium content copper magnesium alloys as diffusion barriers
US20070034517A1 (en) Interconnect structure for semiconductor devices
JP3586605B2 (en) Method for etching silicon nitride film and method for manufacturing semiconductor device
JP4783261B2 (en) Manufacturing method of semiconductor device
JP4266360B2 (en) Cu-based wiring forming method for semiconductor device
JP2006210921A (en) Method of forming metal wiring of semiconductor device
JP2000306996A (en) Fabrication of semiconductor device
JP4637989B2 (en) Method for forming semiconductor wiring film
EP1401015B1 (en) Selective dry etching of tantalum nitride
JP5463794B2 (en) Semiconductor device and manufacturing method thereof
JP2006100698A (en) Method for manufacturing semiconductor device
JP2010080525A (en) Method of manufacturing semiconductor device
US20030022482A1 (en) Method of manufacturing a semiconductor device
JP2010056393A (en) Method of extracting and cleaning metal wire film, metal wire subjected to extracting/cleaning process, and device having same
JP4716323B2 (en) Method for manufacturing Cu wiring film structure
KR100701673B1 (en) METHOD FOR FORMING Cu WIRING OF SENICONDUCTOR DEVICE
JP4660119B2 (en) Manufacturing method of semiconductor device
JP2004327715A (en) Manufacturing method of multi-layered wiring structure
JP2007081130A (en) Method of manufacturing semiconductor device
JP2018117065A (en) Method of embedding metal film
JP4757372B2 (en) Method for forming buried wiring layer
JP2001118804A (en) Semiconductor device and manufacturing method thereof
JP2005051185A (en) Heat treatment method and method for manufacturing semiconductor device