WO2008065925A1

WO2008065925A1 - SEMICONDUCTOR DEVICE Cu WIRING AND METHOD FOR MANUFACTURING THE SAME

Info

Publication number: WO2008065925A1
Application number: PCT/JP2007/072417
Authority: WO
Inventors: Hirotaka Ito; Takashi Onishi; Mikako Takeda; Masao Mizuno
Original assignee: Kabushiki Kaisha Kobe Seiko Sho
Priority date: 2006-11-28
Filing date: 2007-11-19
Publication date: 2008-06-05

Abstract

A semiconductor device Cu wiring is embedded in a wiring groove or an interlayer connecting path formed on an insulating film on a semiconductor substrate. The Cu wiring is composed of a barrier layer, which is formed on the side of the wiring groove or the interlayer connecting path and is made of TaN, and a wiring main body section made of Cu containing one or more kinds of elements selected from among a group of Pt, In, Ti, Nb, B, Fe, V, Zr, Hf, Ga, Tl, Ru, Re and Os by 0.05-3.0 atm% in total. The semiconductor device Cu wiring has excellent adhesion between the wiring main body section and the barrier layer.

Description

Specification

Cu wiring of semiconductor device and manufacturing method thereof

Technical field

The present invention relates to a semiconductor device, and more specifically, for example, Cu wiring in a semiconductor device such as a Si semiconductor device represented by ULSI (Ultra Large Scale Integrated Circuit). And a method of forming the Cu wiring.

Background art

[0002] In recent years, design standards (design rules) have become stricter in order to meet the demands for higher integration of LSIs (Large Scale Integrated Circuits) and high-speed signal propagation. Wiring pitch, wiring width, distance between wiring, wiring Reduction of interlayer connection paths (vias) that connect each other!

[0003] Further, in order to cope with higher integration of semiconductor devices, it has been studied to use a multilayer structure for wiring, and the ratio of the depth of the wiring groove to the width of the wiring groove (trench) (the depth of the wiring groove). / Width) and the ratio of the depth to the width of the interlayer connection path connecting the upper layer wiring and the lower layer wiring (depth / width of the layer connection path) is increasing.

[0004] Furthermore, with the miniaturization and high integration of wiring circuits, the resistance of the wiring itself is increasing, causing a delay in signal transmission. Therefore, Cu-based wiring materials (hereinafter referred to as Cu-based wiring materials) can be used as wiring materials that can reduce electrical resistance compared to conventional A1-based wiring materials (hereinafter also referred to as A1-based wiring materials). There is an attempt to form a Cu wiring.

A damascene wiring technique is known as a method for forming a multilayered Cu wiring. In this technology, wiring grooves and interlayer connection paths are formed in an insulating film provided on a semiconductor substrate, and these openings are covered with a Cu-based wiring material such as pure Cu or Cu alloy, and then heated. This is a method of forming Cu wiring by flowing Cu-based wiring material under pressure and embedding Cu-based wiring material in wiring grooves and interlayer connection paths. Excess Cu-based wiring material that is not embedded in wiring trenches or interlayer connection paths is removed by chemical mechanical polishing (CMP). [0006] By the way, if the main part of the Cu wiring is brought into direct contact with the insulating film, Cu diffuses into the insulating film and degrades the insulating properties of the insulating film. Therefore, in order to prevent diffusion of Cu into the insulating film, it is necessary to provide a barrier layer between the wiring body and the insulating film. However, in order to embed a Cu-based wiring material formed so as to cover the opening of the wiring groove or interlayer connection path in the wiring groove or interlayer connection path, it is generally heated to a high temperature of about 500 to 700 ° C. The NORIA layer is required to exhibit barrier properties at such high temperatures. For this reason, a metal nitride film such as a TaN film or a TiN film is used as the barrier layer. In particular, TaN films are widely used because they exhibit barrier properties even at higher temperatures than TiN films.

[0007] When the body of the Cu wiring is formed directly on the surface of a ceramic barrier layer such as a rust metal nitride film, the interface between the NORA layer and the Cu wiring becomes the main diffusion path for Cu atoms. Cu may diffuse and voids may form cracks at the interface between the NOR layer and the Cu wiring, or the Cu wiring itself may be disconnected or the wiring may be deformed. These problems are called electomigration (EM) and stress migration (SM). Elect mouth migration refers to a phenomenon in which atoms that make up a wiring material move due to the effects of electron flow and electric field when current is flowing.Stress migration refers to heat transfer even when no current flows. This refers to a phenomenon in which voids are broken at grain boundaries due to activity or tensile stress.

[0008] Moreover, the adhesion between the barrier layer and Cu is poor. Cu wiring force When peeling from the S barrier layer and voids occur at the interface between the barrier layer and the Cu wiring, the reliability of the Cu wiring decreases. Therefore, it is necessary to improve the adhesion between the barrier layer and the Cu wiring.

[0009] The poor adhesion between the noria layer and Cu is described in Patent Document 1, for example. This Patent Document 1 describes that if the adhesion between the noria layer and the Cu wiring is poor, peeling is likely to occur between the noria layer and the Cu wiring. It is noted that the heat stress during the operation of the device causes problems such as disconnection in the wiring, which significantly reduces the reliability of the semiconductor device. Therefore, in Patent Document 1, in order to improve the reliability of a semiconductor device, a conductive layer mainly composed of a refractory metal and Cu is provided between a Cu wiring and an insulating film without providing a noor layer. As the conductive layer, a metal film composed of an intermetallic compound of Ti and Cu is exemplified. In addition, Patent Document 1 describes a gap between a conductive layer and an insulating film. It is described that a noria layer may be provided. However, when the present inventors examined the adhesion of the Cu wiring described in Patent Document 1, it was found that the adhesion between the NOR layer and the wiring was not sufficient and there was room for improvement. It was.

[0010] Further, as described above, in recent years, the width of wiring grooves and interlayer connection paths has become smaller and the depth / width ratio of wiring grooves and interlayer connection paths has become larger and larger! / It is becoming more difficult to reliably embed Cu-based wiring materials in wiring grooves and interlayer connection paths.

Patent Document 1: Japanese Patent Laid-Open No. 10-223635

Disclosure of the invention

The present invention has been made in view of such a situation, and an object of the present invention is to provide a Cu wiring having good adhesion to a barrier layer made of TaN formed on a wiring groove or an interlayer connection path surface. It is to provide a method capable of manufacturing this Cu wiring. Furthermore, another object of the present invention is to provide good adhesion with the noria layer even when the wiring groove formed in the insulating film on the semiconductor substrate or the width of the interlayer connection path is narrow and deep. Another object is to provide a Cu wiring embedded in every corner of the interlayer connection path and a method for manufacturing this Cu wiring.

[0012] The present inventors have intensively studied in order to improve the adhesion between the barrier layer made of TaN and the Cu wiring. As a result, (l) the force to contain a specific amount of a specific element in the wiring body of the Cu wiring, (2) the wiring body of the Cu wiring is pure Cu, and the wiring body and barrier layer made of this pure Cu. If an intermediate layer containing a specific amount of a specific element is interposed in between, the adhesion between the wiring main body and the NORA layer can be improved, and (3) the width of the wiring groove and interlayer connection path is narrow. If the Cu-based wiring material is formed so as to cover the wiring grooves and interlayer connection paths, heat treatment or further pressurization as necessary may result in the wiring grooves and interlayer connection paths. The present invention was completed by finding that it can be embedded in every corner.

That is, the Cu wiring of the semiconductor device according to the present invention that has solved the above problems is a Cu wiring buried in a wiring groove or an interlayer connection formed in an insulating film on a semiconductor substrate. The Cu wiring includes a barrier layer made of TaN formed on the wiring groove side or the interlayer connection path side, Pt, In, Ti, Nb, B, Fe, V, Zr, Hf, Ga, Tl, Ru, It is composed of a wiring main body part made of Cu containing 0.05 to 3.0 atomic% in total of one or more elements selected from the group consisting of Re and Os! [0014] In addition, the above-described problems are (1) a noble layer made of TaN formed on the wiring groove side or the interlayer connection path side, (2) a wiring main body portion made of pure Cu, and (3) the barrier layer. It is formed between and in contact with the wiring main body, and is selected from the group consisting of Pt, In, Ti, Nb, B, Fe, V, Zr, Hf, Ga, Tl, Ru, Re and Os 1 This problem can be solved even with Cu wiring composed of an intermediate layer made of Cu containing a total of O. 05-3. The thickness of the intermediate layer is, for example, 10 to 50 nm.

[0015] The wiring groove or the interlayer connection path may have a width of 0.15 μm or less and a depth ratio (depth / width) of 1 or more.

[0016] Cu wiring of a semiconductor device according to the present invention includes a step of forming a TaN layer on the surface of a wiring groove or an interlayer connection formed in an insulating film on a semiconductor substrate, and a sputtering method on the surface of the TaN layer. A total of one or more elements selected from the group consisting of Pt, In, Ti, Nb, B, Fe, V, Zr, Hf, Ga, Tl, Ru, Re, and Os. It can be manufactured through a process of forming a Cu layer containing 1%. The wiring groove or the interlayer connection path has a width of 0.115 111 or less and a depth ratio (depth / width) of 1 or more, and a Cu layer is inserted in these. If it is difficult to push in, heat it up or pressurize it as needed.

[0017] Further, the Cu wiring of the semiconductor device according to the present invention includes a step of forming a TaN layer on the surface of a wiring groove or an interlayer connection formed in an insulating film on a semiconductor substrate, and sputtering on the surface of the TaN layer. The total amount of one or more elements selected from the group consisting of Pt, In, Ti, Nb, B, Fe, V, Zr, Hf, Ga, Tl, Ru, Re, and Os by the law is 0.05-3. It can also be manufactured through a process of forming a Cu layer containing 0 atomic% and a process of forming a pure Cu layer on the surface of the Cu layer. The wiring groove or the interlayer connection path has a width of not more than 0. Ι δ πι and a ratio of depth to the width (depth / width) of 1 or more, and a pure Cu layer is included in these. If it is difficult to push in, heat it up or pressurize it as needed.

[0018] According to the present invention, the force for appropriately adjusting the component composition of the wiring body portion of the Cu wiring, and, when the wiring body portion of the Cu wiring is pure Cu, between the barrier layer made of pure Cu and TaN, Improve the adhesion between the wiring body and the barrier layer by interposing an intermediate layer with an appropriately adjusted composition! it can. As a result, no voids are generated between the wiring body and the barrier layer, and the reliability of the Cu wiring can be improved. However, according to the present invention, even when the width of the wiring groove or the interlayer connection path is narrow, the Cu-based wiring material is formed so as to cover the wiring groove or the interlayer connection path, and then heated or necessary. By further applying pressure accordingly, Cu-based wiring material can be embedded in wiring grooves and interlayer connection paths that do not impair the adhesion between the NOR layer and the wiring body.

Brief Description of Drawings

[0019] [Fig. 1] Fig. 1 shows the content of adhesion improving elements and the K of the adhesion Cu layer obtained by the MELT method.

It is a graph which shows appl relation. Fig. 1 (b) is a graph enlarging the range of 0 to 0.2 atomic% of Fig. 1 (a).

[Fig. 2] Fig. 2 is a graph showing the relationship between the Fe content and the K of the adhesive Cu layer obtained by the MELT method.

appl

It is rough.

[FIG. 3] FIG. 3 is a graph showing the relationship between the temperature of atmospheric annealing or high-pressure annealing and the K of the adhesive Cu layer obtained by the MELT method.

appl

[Fig. 4] Fig. 4 shows the content of adhesion improving elements and the K content of the adhesion Cu layer obtained by the MELT method.

appl

[Figure 5] Figure 5 shows the relationship between the thickness of the adhesive Cu layer and the K of the adhesive Cu layer obtained by the MELT method.

appl

[Figure 6] Figure 6 shows the relationship between the thickness of the adhesive Cu layer and the K of the adhesive Cu layer obtained by the MELT method.

appl

[FIG. 7] FIG. 7 is a graph showing the relationship between the temperature of atmospheric annealing or high-pressure annealing and the K of the adhesive Cu layer obtained by the MELT method.

appl

[Fig. 8] Fig. 8 shows the content of the adhesion improving element and the K of the adhesion Cu layer obtained by the MELT method.

It is a graph which shows appl relation. (B) in FIG. 8 is a graph obtained by enlarging the range of 0 to 0.2 atomic% in (a) of FIG.

[Fig. 9] Fig. 9 shows the content of the adhesion improving element and the K of the adhesion Cu layer obtained by the MELT method.

appl The best mode for carrying out the invention

[0020] To improve the adhesion between the wiring body of the Cu wiring and the barrier layer made of TaN, It is important to appropriately adjust the component composition of the layer in direct contact with the substrate.

That is, when the layer directly in contact with the NOR layer is the wiring body part, the wiring body part is one or more elements selected from the group consisting of Pt, In, Ti, Nb, B, and Fe, or these In addition to the above elements, a wiring made of Cu containing 0.05 to 3.0 atomic% in total of one or more elements selected from the group consisting of V, Zr, Hf, Ga, Tl, Ru, Re and Os And it is sufficient. On the other hand, when the wiring body is pure Cu, one type selected from the group force consisting of Pt, In, Ti, Nb, B, and Fe so as to be in contact with the barrier between the wiring body and the barrier layer. In addition to these elements, or in addition to these elements, one or more elements selected from the group consisting of V, Zr, Hf, Ga, Tl, Ru, Re, and Os are combined. An intermediate layer made of Cu may be provided.

[0022] Pt, In, Ti, Nb, B, Fe, V, Zr, Hf, Ga, Tl, Ru, Re, and Os all consist of TaN as a result of various experiments conducted by the inventors. It is an element that has been found to have an effect of improving the adhesion between the barrier layer and Cu (hereinafter, sometimes referred to as an adhesion improving element). The reasons why these adhesion improving elements enhance the adhesion between the barrier layer and Cu are considered as follows.

[0023] Pt, B, Ru, Re, and Os are precipitated at the interface between the barrier layer and Cu (the wiring body containing the adhesion improving element or the intermediate layer containing the adhesion improving element) and remain at the interface. It is considered that it has the action of relaxing the residual stress. Residual stress is most highly applied to the interface between the noria layer and Cu, so it is considered that the adhesion to the Cu barrier layer is improved by relaxing this residual stress.

[0024] In, Ga, and T1 diffuse at the interface between the NOR layer and Cu to form an alloy layer of Ta, In, Ga, or T1 at the interface, and this alloy layer adheres to the barrier layer and Cu. It is thought that it works to improve. In particular, In has a melting point of about 156 ° C, Ga has a melting point of 29.76 ° C, and T1 has a melting point of 294 ° C, which is low, less than about 50 ° C. It is done.

[0025] Ti, Nb, Fe, V, Zr, and Hf are all elements selected in consideration of the chemical equilibrium calculation power and reactivity with the barrier layer. Compounds and chemical bonds are formed between them, and the adhesion of Cu to the barrier layer is thought to improve. For example, Ti is considered to form TiN when in contact with a barrier layer made of TaN, and this TiN is considered to improve the adhesion of Cu to the barrier layer. Fe consists of TaN By contacting with the noria layer, it is considered that Fe ₂ Ta or FeTa ₂ is formed on the low temperature side and the adhesion of these compound forces SCu to the barrier layer is improved. Nb comes into contact with a TaN barrier layer to form NbN, and this NbN is thought to improve the adhesion of Cu to the barrier layer. V comes into contact with a barrier layer made of TaN to form VN, and this VN is considered to improve the adhesion of Cu to the barrier layer. Zr comes into contact with a barrier layer made of TaN to form ZrN, which is thought to improve the adhesion of Cu to the barrier layer. It is considered that Hf forms HfN by coming into contact with a TaN barrier layer, and this HfN improves the adhesion of Cu to the barrier layer.

[0026] When the Cu layer containing the above-mentioned adhesion improving element is provided as a wiring main body portion, the adhesion improving element is used in order to increase the adhesion to the barrier layer and not to increase the electrical resistivity of the wiring itself. Among these, it is particularly preferable to contain B or Pt. Further, in order to improve the adhesion to the barrier layer and to improve the embedding property in the wiring groove or the interlayer connection path, it is particularly preferable to contain In among the above-mentioned adhesion improving elements.

[0027] On the other hand, when a Cu layer containing the above-mentioned adhesion improving element is provided as an intermediate layer, in order to mainly improve the adhesion with the barrier layer, among the above-mentioned adhesion improving elements, particularly Nb and Ti , Fe is preferably contained.

In the present invention, the Cu layer containing the above-mentioned adhesion improving element may be referred to as an adhesive Cu layer regardless of the case where it is provided as a wiring body portion or an intermediate layer.

[0029] The amount of the adhesion improving element contained in the wiring main body or the intermediate layer may be 0.05 to 3.0 atomic% in total. If the adhesion improving element is less than 0.05 atomic%, the adhesion between the NOR layer and the wiring main body cannot be sufficiently improved. The content of the adhesion improving element is 0.05 atomic% or more, preferably 0.5 atomic% or more, more preferably 1 atomic% or more, and even more preferably 1.5 atomic% or more. However, even if an adhesion improving element is contained excessively, the effect is saturated, and the excessive element increases the electrical resistivity of the Cu wiring. Therefore, the content of the adhesion improving element is 3.0 atomic% or less, preferably 2.5 atomic% or less, more preferably 2.0 atomic% or less.

[0030] The thickness of the intermediate layer is not particularly limited, but is preferably 10 nm or more in order to improve the adhesion between the barrier layer and the wiring body. More preferably 15 nm or more, still more preferably 20 nm or more Above. However, even if the intermediate layer is made too thick, the effect of improving the adhesion between the barrier layer and the wiring body is saturated, so the upper limit of the intermediate layer thickness should be about 50 nm. More preferably, it is 45 nm or less, More preferably, it is 40 nm or less.

[0031] The thickness of the intermediate layer refers to the cross section of the Cu wiring cut so that the shape of the wiring groove or interlayer connection path formed in the insulating film is exposed, and the inner wall (side wall or side wall of the wiring groove or interlayer connection path). It means the smallest thickness when the thickness of the intermediate layer formed along the bottom surface is measured. For example, an intermediate layer is easily formed on the bottom surface of a wiring groove or an interlayer connection path, but an intermediate layer is not easily formed on the side wall of the wiring groove or the interlayer connection path. Therefore, the thickness of the intermediate layer formed on the side wall of the wiring groove or the interlayer connection path tends to be small.

[0032] The type of insulating film in which the wiring trench or interlayer connection path is formed is not particularly limited. For example, silicon oxide is silicon nitride, BSG (Boro-Silicate Glass), PSG (Phospho-Silicat e01 & 33) 8-30

, £ 03 10?) Etc. can be used.

Next, a method for manufacturing the Cu wiring of the present invention will be described. If the layer that is in direct contact with the NOR layer is the wiring body, a TaN layer is formed on the surface of the wiring groove or interlayer connection formed in the insulating film on the semiconductor substrate, and then the surface of this TaN layer is sputtered. 1 or more elements selected from the group consisting of Pt, In, Ti, Nb, B, Fe, V, Zr, Hf, Ga, Tl, Ru, Re, and Os (adhesion improving element) in total 05 ～ 3.0 Adhesive Cu layer (ie, the wiring body) should be formed! /.

[0034] The method for forming the TaN layer is not particularly limited, and may be formed by sputtering (for example, DC magnetron sputtering) or CVD!

[0035] In order to form an adhesive Cu layer on the surface of the TaN layer, a sputtering method may be employed. If the sputtering method is adopted, an adhesive Cu layer containing an adhesion improving element can be easily formed on the surface of a wiring groove with an TaN layer or an interlayer connection path.

[0036] The sputtering method may be, for example, a (DC) magnetron sputtering method or a long throw sputtering method. In particular, the long throw sputtering method can be preferably employed from the viewpoint of embedding properties as described later. The long throw sputtering method is a sputtering method in which the distance between the wafer and the target is long. Sputtering with a thickness of at least mm is called long throw sputtering.

[0037] To form an adhesion Cu layer containing an adhesion improving element by sputtering, a Cu target containing an adhesion improving element is used as a sputtering target, or adhesion to the surface of a pure Cu target. Sputtering may be performed in an inert gas atmosphere using a chip-on target to which a Cu piece containing an improving element or a metal piece made of an adhesion improving element is attached.

[0038] As the inert gas, for example, helium, neon, argon, krypton, xenon, or radon can be used. Argon or xenon is preferably used, and especially argon is relatively inexpensive and can be suitably used. Other sputtering conditions (for example, ultimate vacuum, sputtering gas pressure, discharge power density, substrate temperature, interelectrode distance, etc.) are not particularly limited, and may be adjusted within a normal range.

[0039] The thickness of the adhesive Cu layer formed by sputtering may be changed according to the depth of the wiring groove or interlayer connection path. The adhesive Cu layer having a thickness at least equal to the depth of the wiring groove or interlayer connection path. May be formed. The upper limit of the thickness of the adhesive Cu layer is, for example, 2. If the thickness is too large, the strength of the adhesive Cu layer will increase, so that it will be difficult to embed the adhesive Cu layer in the wiring trench or interlayer connection path even after heating and pressurizing as described later.

[0040] On the other hand, when the wiring body is pure Cu, a TaN layer is formed on the surface of the wiring trench or interlayer connection path formed in the insulating film on the semiconductor substrate, and then sputtered on the surface of this TaN layer. One or more elements selected from the group consisting of Pt, In, Ti, Nb, B, Fe, V, Zr, Hf, Ga, Tl, Ru, Re, and Os in a total of 0.05 to 3. An adhesive Cu layer containing 0 atomic% (that is, an intermediate layer) may be formed, and then a pure Cu layer (that is, a wiring body portion) may be formed on the surface of the adhesive Cu layer.

[0041] The method for forming the adhesive Cu layer as an intermediate layer on the surface of the TaN layer may be the same as the method for forming the adhesive Cu layer as the wiring body.

[0042] When an adhesive Cu layer is formed as an intermediate layer between the noria layer and the wiring main body, the thickness of the adhesive Cu layer may be about 10 to 50 nm.

[0043] The method of forming a pure Cu layer is not particularly limited! /, But, for example, an electrolytic plating method, a chemical vapor deposition method (CVD method), an (arc) ion plating method, a sputtering method, etc. can be adopted. wear. In particular, if the electrolytic plating method is used, it is possible to fill a pure Cu layer while gradually burying it from the bottom of the wiring groove or interlayer connection path. As the sputtering method, for example, a (DC) magnetron sputtering method or a long throw sputtering method may be used. In particular, the long throw sputtering method can be preferably employed from the viewpoint of embedding. For example, the purity of pure Cu may be 99 atomic% or more (particularly 99.9-99.99 atomic%).

[0044] If the thickness of the pure Cu layer is changed according to the depth of the wiring groove or interlayer connection path, the thickness of the pure Cu layer is at least equal to the depth of the wiring groove or interlayer connection path. Do it! / The upper limit of the thickness of the pure Cu layer is, for example, 2. If the thickness becomes too large, the strength of the pure Cu layer will increase, so when forming a pure Cu layer by sputtering, the pure Cu layer will be connected to wiring trenches and interlayer connections even when heated and pressurized as described later. It becomes difficult to embed in the road.

[0045] For example, when the width of a wiring groove or interlayer connection path is 0.15 μm or less and the ratio of depth to this width (depth / width) is 1 or more, Cu containing an adhesion improving element When a wiring layer or pure Cu layer is formed by sputtering as a wiring body, the wiring body or wiring layer is not completely embedded in the wiring groove or interlayer connection path because the wiring groove or interlayer connection path is narrow and deep. The main body part may be bridged so as to cover the wiring groove and the opening of the interlayer connection path, and a gap may be formed inside the wiring groove and the interlayer connection path.

Therefore, when the wiring main body is formed by the sputtering method, it is preferable to press the wiring main body into the wiring groove or the interlayer connection path by applying pressure while heating. Specifically, it is preferable to pressurize to 150 MPa or more (preferably 160 MPa or more) while heating to 500 ° C or more (preferably 550 ° C or more). The upper limit of heating temperature is about 700 ° C. Equipment that heats above 700 ° C is practically difficult, and if the temperature is too high, the electrical resistivity of the Cu wiring tends to increase. In addition, the semiconductor substrate itself may be deformed. A preferred upper limit is 650 ° C, and a more preferred upper limit is 600 ° C. In addition, although the atmosphere at the time of heating is not specifically limited, For example, what is necessary is just the above-mentioned inert gas atmosphere. The pressure is preferably as high as possible, but if it exceeds 200 MPa, the pressure is too high to be practical, so the upper limit is about 200 MPa. Preferably it is 180 MPa or less.

[0047] Even if the width of the wiring groove or interlayer connection path is 0.15 μm or less and the ratio of the depth to this width (depth / width) force or more, the wiring main body is subjected to the long throw sputtering method. Formed with By doing so, the wiring main body can be almost surely embedded in the wiring groove or the interlayer connection path. Accordingly, when the wiring main body is formed by the long throw sputtering method, it is not necessary to heat and pressurize, but it may be heated, pressed or heated and pressed as necessary. In addition, when the wiring main body is pure Cu, the wiring groove or the interlayer connection path where the pure Cu layer may be formed by the electrolytic plating method has a width of 0.15 m or less, and the depth relative to this width. Even if the ratio (depth / width) is 1 or more, a pure Cu layer can be almost surely embedded in the wiring trench and the interlayer connection path. Therefore, even when a pure Cu layer is formed by an electrolytic plating method, it is not necessary to apply heat and pressure, but it may be heated, pressurized, or heated and pressed as necessary.

[0048] The temperature at the time of heating should be above room temperature, for example, 50 ° C or higher (particularly 200 ° C or higher). For example, IMPa or more (especially lOMPa or more) is sufficient if the pressure is higher than normal pressure.

[0049] However, when heating is performed without applying pressure, the adhesion deteriorates. When heated, the tensile stress applied to Cu is increased compared to before heating, and this tensile stress acts to promote Cu delamination from the noria layer against adhesion. On the other hand, when heating and pressurization are performed together, for example, an amorphous layer in which Cu and Ta are mixed is formed at the interface between the barrier layer that also has TaN force and Cu, and the thickness of this amorphous layer is reduced. By increasing, the adhesion of Cu to the barrier layer is improved. Therefore, even when the wiring main body is formed by the long throw sputtering method, it is preferable to apply heat and pressure.

[0050] The heating temperature at the time of heating and pressurization may be, for example, 50 ° C or more (particularly 200 ° C or more) as long as it exceeds room temperature. The pressure at the time of heating and pressing is, for example, 50 MPa or more (particularly, 100 MPa or more).

[0051] The film thickness of the adhesive Cu layer, pure Cu layer, and barrier layer made of TaN can be adjusted by controlling the formation conditions of each layer. That is, if a dummy thin film is formed in advance by appropriately controlling the formation conditions of each layer, and the film thickness of this thin film is measured with a stylus type film thickness meter, the film thickness can be controlled by controlling the formation conditions of each layer. Can be adjusted.

Example

[0052] Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples are not intended to limit the present invention, and are appropriately modified within a range that can meet the gist of the preceding and following description. Fruit It is also possible to apply them, and they are included in the technical scope of the present invention.

[0053] [Experiment 1]

A TaN layer is formed on the surface of a φ4 inch silicon wafer by DC magnetron sputtering to a thickness of 50 nm, and then contains a pure Cu layer (No. 1 in Table 1 below) or the elements shown in Table 1 below. Adhesive Cu layer (the remainder is Cu and inevitable impurities) was deposited by DC magnetron sputtering to a thickness of 200 nm to obtain a laminate.

[0054] As a sputtering apparatus, an HSM-552 type sputtering apparatus manufactured by Shimadzu Corporation was used, and sputtering was performed using a pure Cu target or a chip-on target. As a chip-on target, 3 to 6 erosion positions of 5 mm square metal chips (Cu chips containing a desired element or metal chips made of a desired element) on the surface of a pure Cu target (φ 100 mm) as a base The adhesive Cu layer composition is adjusted by changing the type of the metal tip using the one pasted, and the composition contained in the adhesive Cu layer is controlled by changing the number of metal tips and the location of the metal tip. did.

[0055] Sputtering conditions for forming the TaN layer, the ultimate pressure of 133 X 10- ⁶ Pa or less (

1 X 10- ⁶ Torr or less), a mixed gas (N gas 2 0 vol ^_0/0 Ar gas containing the atmospheric gas during sputtering Ar and N), the sputtering gas pressure 667 X 10- ³ Pa (5 X 10- ³ Torr), the discharge path Wa density ^{2. 0W / cm 2 (DC)} , at room temperature and the substrate temperature (Ts = 20 ° C), and the distance between electrodes 55 mm, and.

[0056] Sputtering conditions when forming a pure Cu layer or an adhesive Cu layer are based on the ultimate vacuum.

133 X 10- ⁶ Pa or less (1 X 10- ⁶ Torr or less), the ambient gas during sputtering Ar gas, scan Pattagasu pressure of ^{267 X 10- 3 Pa (2 X} 10- 3 Torr), the discharge power density 3 2 W / cm ² (DC), substrate temperature was room temperature (Ts = 20 ° C), and distance between electrodes was 55 mm. In the example shown in No. 8 shown in Table 1 below, a pure Cu target was used as the sputtering target, and the atmosphere gas during sputtering was a mixed gas of Ar and N (Ar gas containing 3% by volume of N gas). An adhesive Cu layer was formed.

[0057] Adhesiveness deposited by sputtering The amount of adhesion-enhancing element contained in the Cu layer was quantified by ICP emission spectroscopy using an ICP emission spectrometer “ICP-8000” manufactured by Shimadzu Corporation . [0058] With respect to the obtained laminate, the adhesion of the pure Cu layer or the adhesion Cu layer to the TaN layer was evaluated by measuring the adhesion force by MELT method. The MELT method is the application of an epoxy resin to the surface of a pure Cu layer or adhesive Cu layer, and cooling it to apply the pure Cu layer or adhesive Cu layer to the TaN layer using the stress applied to the epoxy resin. This is a method for measuring the force (adhesion) when peeling from the interface. The adhesion force is the force Gc (j / m ² ) required to separate the pure Cu layer or adhesion Cu layer at the interface with the TaN layer, and is expressed by the following formula (1). ).

[0059] [Equation 1]

[0060] [Equation 2]

In the above formula (1), U is the adhesion force (J) of the pure Cu layer or adhesive Cu layer to the TaN layer, and A is the adhesion area (m ² ). In the above equation (2), σ is the residual stress of the epoxy resin layer, h is the Epoch

0

The thickness of the xy-resin layer, V is the Poisson's ratio of the epoxy resin layer, and E is the yang ratio of the epoxy resin layer. In the above equation (2), h, V, and E are known values determined by the type of epoxy resin. The residual stress σ (Pa) of the epoxy resin layer and the thickness h of the epoxy resin layer h

K (Pa -m ¹ ") obtained from (m) by the following equation (3) can also be used as an index of adhesion.

appl

it can. The larger the K value, the better the adhesion.

[0062] [Equation 3]

K _appl = o ₀ fh / 2 (3) [0063] Specifically, the adhesion was measured by the following procedure. An epoxy resin is applied to the surface of a pure Cu layer or adhesive Cu layer deposited on the surface of a silicon wafer to a thickness of 100 m, and this is baked at 170 ° C for 1 hour, and then a peripheral slicer (dicing solution). 1) was cut into 12mm x 12mm square. The edge of the four corners of the cut specimen (coupon) was polished with emery paper and finished with # 1000. For the obtained specimen, the adhesion of the pure Cu layer or adhesion Cu layer to the TaN layer was measured using a thin film adhesion tester (FMS Laminar Series II) manufactured by FMS. The adhesion force is determined by cooling the obtained specimen in the chamber, measuring the temperature at which the pure Cu layer or adhesive Cu layer peels from the TaN layer, and obtaining σ from this temperature, Κ value was calculated from Table 1 below shows the K values of pure Cu or adhesive Cu layers determined by the MELT method.

[0064] From Table 1 below, it can be considered as follows. No. 1 is a series of pure Cu layers stacked on a TaN layer, and consists of Pt, In, Ti, Nb, B, and Fe, as in Nos. 2 to 7, rather than No. 1 An adhesive Cu layer containing one or more elements selected from the group in a range of 0.05 to 30 atomic percent is superior in adhesion. On the other hand, No. 8 is an example in which an adhesive Cu layer containing N is laminated on the TaN layer, and No. 9 is an example in which an adhesive Cu layer containing Sb is laminated on the TaN layer. , Adhesion No improvement in adhesion of the Cu layer was observed.

[0065] [Table 1]

Composition of Cu alloy thin film

• ^ a pl

No. content

Alloy elements (MPa-m ^1/2 )

(Atom%)

1 .1 1 0.16

2 Pt 2.12 0.22

3 In 1.07 0.23

4 Ti 1.79 0.41

5 Nb 2.35 0.45

6 B 0.79 0.26

7 Fe 1.88 0.28

8 N 0.50 0.16

9 Sb 1.93 0.08

[0066] [Experiment 2]

Except that in Example 1 above, an adhesive Cu layer with the Pt, In, Ti, Nb, B or Fe content adjusted on the surface of the TaN layer was formed (the remainder being Cu and inevitable impurities). A laminate was obtained under the same conditions as in 1.

[0067] With respect to the obtained laminate, the adhesion of the Cu layer to the TaN layer was measured under the same conditions as in Experimental Example 1. Figure 1 shows the relationship between the content of adhesion improving elements and the adhesion Cu layer determined by the MELT method. In Figure 1, the mouth is Pt, · is In, ○ is Ti, ♦ is Nb, appl O is B, and country is Fe. Fig. 1 (b) is a graph enlarging the range of 0 to 0.2 atomic% in Fig. 1 (a).

As shown in FIG. 1 (a), the adhesion to the TaN layer increases as the content of the adhesion improving element increases. In particular, when Nb or Ti is included as an element for improving adhesion, the adhesion can be improved by about twice or more compared to the case where other elements are included. You can. However, the adhesion improving effect tends to saturate even if the adhesion improving element exceeds 3 atomic%.

[0069] As is apparent from (b) of Fig. 1, it can be seen that the adhesion improving effect is rapidly exerted by adding 0.05 atomic% of the adhesion improving element.

[0070] [Experiment 3]

In Experimental Example 1 above, after forming an adhesive Cu layer with the Fe content adjusted on the surface of the TaN layer (the remainder being Cu and inevitable impurities), heating at normal pressure (hereinafter referred to as normal pressure annealing treatment) The laminate was obtained by applying pressure (hereinafter also referred to as high-pressure annealing) while heating. Normal pressure annealing is performed in an Ar atmosphere at normal pressure (0. IMPa), heated to 500 ° C at a heating rate of 5 ° C / min, held at 500 ° C for 15 minutes, and then cooled to room temperature. Cooled at a rate of 5 ° C / min. High pressure Aniru process, a vacuum of 133 X 10- ⁶ Pa or less (1 X 10- ⁶ Torr or less), pressure Caro to 150 MPa, and heated at 500 ° C until a Atsushi Nobori rate 15 ° C / min from room temperature, 500 ° After holding at C for 15 minutes, it cooled to room temperature at a cooling rate of 10 ° C / min.

[0071] With respect to the obtained laminate, the adhesion of the Cu layer to the TaN layer was measured under the same conditions as in Experimental Example 1. Relation between Fe content and adhesion obtained by MELT K of Cu layer

Figure 2 shows the appl staff. In Fig. 2, · indicates atmospheric pressure annealing, and ▲ indicates high pressure annealing. Fig. 2 also shows the results for both cases (untreated; ◯) without normal pressure annealing or high pressure annealing.

[0072] As is apparent from FIG. 2, even if the adhesive Cu layer is still formed on the TaN layer (untreated), after forming the adhesive Cu layer, normal pressure annealing or high pressure annealing treatment is performed. Even so, as the Fe content increases, the adhesion to the TaN layer increases the adhesion of the Cu layer. However, in any case, even if Fe is contained in an amount exceeding 3 atomic%, the adhesion improving effect tends to be saturated.

[0073] Adhesiveness It can be seen that if the atmospheric annealing process is performed after the Cu layer is formed, the adhesive force is lower than that in the case of no treatment. On the other hand, it can be seen that if the high-pressure annealing treatment is performed after forming the adhesive Cu layer, the adhesion strength is improved as compared with the case of no treatment. When the normal pressure annealing treatment is performed, the adhesion strength is lower than that when the treatment is not performed. This is considered to be governed by both the lowering and the improvement of the adhesion by pressurization. In other words, in the normal pressure annealing treatment, the adhesion lowering effect due to heating acts strongly, so that the adhesion strength is considered to be lower than that in the case of no treatment.

[0074] [Experiment 4]

In Example 1 above, after forming an adhesive Cu layer containing 1.88 atomic% Fe on the surface of the TaN layer (the remainder being Cu and inevitable impurities), is heating at normal pressure as in Example 3 above? (Normal pressure annealing treatment) and pressurizing (high pressure annealing treatment) while heating to obtain a laminate.

[0075] The atmospheric annealing treatment was carried out in an Ar atmosphere at normal pressure (0. IMPa) while being heated for 15 minutes. High pressure Aniru process, a vacuum of 133 X 10- ⁶ Pa or less (1 X 10- ⁶ Torr or less), pressurized to 150 MPa, was carried out for 15 minutes in a heated state. In normal pressure annealing and high pressure annealing, the heating temperature is 200 ° C, 500 ° C, 700 ° C, the heating rate during heating is 5 ° C / min, and the cooling rate after heating is 5 ° C / min. Minutes.

[0076] With respect to the obtained laminate, the adhesion of the Cu layer to the TaN layer was measured under the same conditions as in Experimental Example 1. Figure 3 shows the relationship between the temperature of atmospheric annealing or high-pressure annealing and the K of the adhesion Cu layer determined by the ME LT method. In Fig. 3,

appl

Neal processing and ▲ indicate the results of high-pressure annealing. In addition, Fig. 3 also shows the results of the normal pressure treatment and the high pressure annealing treatment! /, And the case (untreated; ○).

As is apparent from FIG. 3, when pressure is applied, the annealing treatment at a high temperature can enhance the adhesion of the Cu layer to the TaN layer. On the other hand, it can be seen that when heated at normal pressure, the adhesion to the TaN layer decreases slightly as the temperature increases.

[0078] [Experiment 5]

In Example 1 above, after forming an adhesive Cu layer with the Pt, In, Ti, Nb, B, or Fe content adjusted to 50 nm on the surface of the TaN layer (the remainder being Cu and inevitable impurities), pure Cu The layer was formed by DC magnetron sputtering to a thickness of 200 nm to obtain a laminate.

[0079] The obtained laminate was bonded to TaN layer under the same conditions as in Experimental Example 1 Cu The adhesion of the layers was measured. Figure 4 shows the relationship between the content of adhesion improving elements and the adhesion Cu layer determined by the MELT method. In Fig. 4, the mouth is Pt, · is In, ○ is Ti, ♦ is Nb, ◊ appl

Shows the result of B, and the country shows the result of Fe.

[0080] As is apparent from FIG. 4, even when a pure Cu layer is formed on the surface of the adhesive Cu layer, the adhesive Cu layer adheres to the TaN layer as the amount of the adhesion improving element contained in the adhesive Cu layer increases. The adhesion strength of becomes higher. However, even if the adhesion improving element is contained in an amount exceeding 3 atomic%, the adhesion improving effect tends to be saturated.

[0081] [Experiment 6]

In Example 1 above, an adhesive Cu layer containing 1.79 atomic percent of Ti (the remainder is Cu and inevitable impurities) is formed on the surface of the TaN layer by 10 to 50 nm, and then the pure Cu layer is formed by DC magnetron sputtering. The film was formed to a thickness of 200 nm to obtain a laminate A. Also, instead of depositing a pure Cu layer by DC magnetron sputtering, a laminate B was obtained by depositing a film to a thickness of 200 nm by electrolytic plating. The electrolytic plating became fi at a current density of 17 mA / cm ² .

[0082] With respect to the obtained laminate A and laminate B, the adhesion to the TaN layer was measured under the same conditions as in Experimental Example 1 above. Figure 5 shows the relationship between the adhesion Cu layer thickness and the K of the adhesion Cu layer determined by the MELT method. In Fig. 5, ○ indicates pure Cu layer and DC magnetrons appl

The results of an example formed by the knocking method (laminate A), and the example of the pure Cu layer formed by the electrolytic plating method (laminate B) are shown.

[0083] As is apparent from FIG. 5, whether the pure Cu layer is formed on the adhesive Cu layer by the DC magnetron sputtering method or the electrolytic plating method, the adhesive Cu layer to the TaN layer is formed. It can be seen that the adhesive strength of the material hardly changes.

[0084] [Experiment 7]

In Example 1 above, an adhesive Cu layer containing 2.35 atomic percent of Nb (the remainder is Cu and inevitable impurities) is formed on the surface of the TaN layer to 10 to 50 nm, and then the pure Cu layer is formed by DC magnetron sputtering. Then, a film was formed to a thickness of 200 nm, and then a layered product was obtained by applying pressure (high pressure annealing treatment) while heating with normal pressure (normal pressure annealing treatment) and heating. The normal pressure annealing and the high pressure annealing were performed under the conditions shown in Experimental Example 3 above. [0085] With respect to the obtained laminate, the adhesion of the Cu layer to the TaN layer was measured under the same conditions as in Experimental Example 1. Figure 6 shows the relationship between the thickness of the adhesive Cu layer and the K of the adhesive Cu layer determined by the MELT method. In Fig. 6, · is normal pressure annealing, ▲ is high pressure annealing appl

The results of the processing are shown respectively. Figure 6 also shows the results of the normal pressure annealing and the high pressure annealing! /, And the case (untreated; ○).

[0086] As is apparent from FIG. 6, it can be seen that increasing the thickness of the adhesive Cu layer increases the adhesive force of the adhesive Cu layer to the TaN layer. In addition, it can be seen that if the atmospheric pressure annealing is performed after forming the adhesive Cu layer, the adhesive strength is lower than that in the case of no treatment. On the other hand, it can be seen that if the high pressure annealing treatment is performed after forming the adhesive Cu layer, the adhesion strength is improved as compared with the case of no treatment.

[0087] [Experiment 8]

In Example 1 above, after forming an adhesive Cu layer containing 1.88 atomic% Fe (the remainder is Cu and inevitable impurities) to 50 nm on the surface of the TaN layer, the thickness of the pure Cu layer is increased by the DC magnetron sputtering method. A film was formed to 200 nm, and then heated at normal pressure (normal pressure annealing treatment) or pressurized (high pressure annealing treatment) while heating to obtain a laminate. Normal pressure annealing and high pressure annealing were performed under the conditions shown in Experimental Example 3 above.

[0088] With respect to the obtained laminate, the adhesion of the Cu layer to the TaN layer was measured under the same conditions as in Experimental Example 1. Figure 7 shows the relationship between the temperature of atmospheric annealing or high-pressure annealing and the K of the adhesion Cu layer determined by the ME LT method. In Fig. 7, · is the atmospheric pressure key.

appl

Neal processing and ▲ indicate the results of high-pressure annealing. In addition, Fig. 7 also shows the results of the normal pressure treatment and the high pressure annealing treatment! /, And the case (untreated; ○) results!

As is apparent from FIG. 7, when pressurizing, annealing at a high temperature can enhance the adhesion of the Cu layer to the TaN layer. On the other hand, when heating at normal pressure, it can be seen that the higher the heating temperature, the lower the adhesion of the Cu layer to the TaN layer.

[0090] [Experiment 9]

An insulating film (TEOS film: SiOF film) formed on the surface of a silicon wafer has a diameter of 0 · 12 [im An evaluation element (TEG) provided with vias having a thickness of 120 nm), a depth of 0.55 m (550 nm), and a pitch of 450 nm was used. On the surface of this TEG, a TaN layer was deposited by DC magnetron sputtering so that the thickness was 50 nm under the same conditions as in Experiment 1 above, and then an adhesive Cu layer containing 1.88 atomic% Fe ( The balance was Cu and inevitable impurities) were deposited by sputtering (CS method) or mouth-throw sputtering method (LTS method) to a thickness of 500 nm.

[0091] Adhesive The sputtering conditions for forming the Cu layer are the same as those shown in Experimental Example 1 above. Long throw sputtering conditions for forming the adhesion Cu layer is reached vacuum degree 133 X 10- ⁶ Pa or less (1 X 10- ⁶ Torr or less), Ar gas ambient gas during sputtering, the sputtering gas pressure the ^{266 X 10- 3 Pa (2 X} 10- 3 Torr), the discharge power density of 25W / cm 2 (0, a substrate Baiasu -200 ¥, the substrate temperature Ts 0 ° C, the distance between electrodes was 300 mm, and .

[0092] Adhesiveness After the Cu layer was formed, the laminate was obtained by heating at normal pressure (normal pressure annealing treatment) as in Experimental Example 3 above or by applying pressure (high pressure annealing treatment) while heating. . The normal pressure annealing and the high pressure annealing were performed under the conditions shown in Experimental Example 4 above. Note that No. 11 and No. 18 in Table 2 below are examples in which normal pressure annealing and high pressure annealing are performed after forming an adhesive Cu layer.

[0093] The processed TEG is processed with a focused ion beam device (FIB device) so that the via cross-section is exposed, and the cross-section is observed with a SIM image of the FIB device. The embedded state (embedding characteristics) of the layer was investigated. The embedding characteristics were evaluated using the embedding rate calculated by the following equation (4) by analyzing the SIM image of the via cross section. 15 vias were observed, and the filling rate was calculated for each via and averaged. The embedding rate is shown in Table 2 below.

Embedding rate (%) = [(embedded in via! /, Cross-sectional area of Cu layer) / (cross-sectional area of via)] X 100 · · · (4)

As can be seen from Table 2, when the adhesive Cu layer is formed by sputtering to embed the adhesive Cu layer in the via, it is only necessary to pressurize to 150 MPa while heating to 500 ° C or higher. I understand. In addition, when the adhesive Cu layer is formed by the long throw sputtering method, the adhesive Cu layer can be completely embedded in the via by heating regardless of atmospheric pressure. [0094] [Table 2]

CS method = Sputtering method, LTS method = Long throw sputtering method

[0095] [Experiment 10]

In Experimental Example 9 above, on the surface of the TaN layer, an adhesive Cu layer containing 1.79 atomic percent of Ti (with the remainder being Cu and inevitable impurities) is formed to a thickness of 10 to 50 nm by sputtering (CS method). After that, a pure Cu layer was formed to have a thickness of 500 nm by an electrolytic plating method, a sputtering method (CS method), and a long slow sputtering method (LTS method).

[0096] Adhesiveness The sputtering conditions for forming the Cu layer are the same as those shown in Experimental Example 1 above. The electrolytic plating conditions for forming a pure Cu layer are the same as those shown in Experimental Example 6, the sputtering conditions are the same as those in Experimental Example 1, and the long throw sputtering conditions are the same as those in Experimental Example 9.

[0097] After a pure Cu layer was formed, a laminate was obtained by applying pressure (high-pressure annealing) while heating at normal pressure (normal-pressure annealing) as in Experimental Example 4 above. . The normal pressure annealing treatment was carried out in an Ar atmosphere at normal pressure (0. IMPa) while being heated for 15 minutes. High pressure Aniru process, a vacuum of 133 X 10- ⁶ Pa or less (1 X 10- ⁶ Torr or less), pressure Caro to 150 MPa, was carried out for 15 minutes in a heated state. Normal pressure annealing and high pressure annealing In the treatment, the heating temperature was 200 ° C or 500 ° C, the heating rate during heating was 5 ° C / min, and the cooling rate after heating was 5 ° C / min. No. 31-33, No. 38, and No. 44 in Table 3 below are examples in which neither a normal-pressure annealing process nor a high-pressure annealing process is performed after a pure Cu layer is formed.

[0098] Adhesion to the via portion and the embedded state of the pure Cu layer (embedding characteristics) were examined for the TEG after the treatment under the same conditions as in Experimental Example 11. The embedding rate is shown in Table 3 below.

[0099] From Table 3, the following can be considered. No. 3;! -37 are all made by thinning the adhesive Cu layer and forming the pure Cu layer by electrolytic plating, so the adhesive Cu layer and the pure Cu layer can be formed in the recess without annealing. Can be completely embedded. As is clear from Nos. 42 to 43, when a pure Cu layer is formed by sputtering, pressurizing and pressing at 150 MPa while heating to 500 ° C or higher will push the pure Cu layer into the via. be able to. As is clear from Nos. 44 to 50, when a pure Cu layer is formed by long throw sputtering, the pure Cu layer can be pushed into the via without annealing.

[0100] [Table 3]

Annealing conditions

Cu alloy thin film Cu alloy thin film Pure Cu thin film embedding rate

No.

Deposition method Film thickness (nm) Deposition method / dishness Pressure Time (%)

(.C) (MPa) (minutes)

31 CS method 10 Electrolytic plating method None 100

32 CS method 30 Electrolytic plating method None 100

33 CS method 50 Electrolytic plating method None 100

34 CS method 50 Electrolytic plating method 200 0.1 15 100

35 CS method 50 Electrolytic plating method 500 0.1 15 100

36 CS method 50 Electrolytic plating method 200 150 15 100

37 CS method 50 Electrolytic plating method 500 150 15 100

38 CS method 50 CS method None 65

39 CS method 50 CS method 500 0.1 15 68

40 CS method 50 CS method 700 0.1 15 69

41 CS method 50 CS method 200 150 15 78

42 CS method 50 CS method 500 150 15 100

43 CS method 50 CS method 700 150 15 100

44 CS method 50 LTS method None 98

45 CS method 50 LTS method 200 0.1 15 100

46 CS method 50 LTS method 500 0.1 15 100

47 CS method 50 LTS method 700 0.1 15 100

48 CS method 50 LTS method 200 150 15 100

49 CS method 50 LTS method 500 150 15 100

50 CS method 50 LTS method 700 150 15 100

CS method = Sputtering method

[0101] [Experiment 11]

In Example 1 above, except that an adhesive Cu layer (with the balance being Cu and inevitable impurities) with an adjusted content of V, Zr, Re, Ru, Hf, Ga, Os or Tl was formed on the surface of the TaN layer. A laminate was obtained under the same conditions as in Experimental Example 1 above. In addition, since Ga has a low melting point, it is not possible to produce a metal chip having a Ga elemental force. Therefore, for Ga, a Cu alloy chip containing 5 atomic% or 10 atomic% of Ga (the remainder is an inevitable impurity) is manufactured, and a 5 mm square is attached to the surface of a pure Cu target (φ 100 mm). A chip alloy target with 3 to 6 Cu alloy chips pasted near the erosion position was used.

The composition contained in the adhesive Cu layer was controlled by changing the type and number of Cu alloy chips and the position of application.

[0102] With respect to the obtained laminate, the adhesion of the Cu layer to the TaN layer was measured under the same conditions as in Experimental Example 1. Adhesion improving element content and adhesion Cu obtained by MELT method Figure 8 shows the relationship between layers. In Fig. 8, mouth is V, · is Zr, ○ is Re, ♦ is Ru, ◊ appl

Is Hf, country is Ga, △ is Os, ▲ is T1 result. FIG. 8B is a graph obtained by enlarging the range of 0 to 0.2 atomic% in FIG. 8A.

As is clear from (a) of FIG. 8, as the content of the adhesion improving element increases, the adhesion to the TaN layer increases the adhesion of the Cu layer. However, even if the adhesion improving element is contained in an amount exceeding 3 atomic%, the adhesion improving effect tends to be saturated.

[0104] As is clear from (b) of Fig. 8, it can be seen that the adhesion improving effect is rapidly exhibited by adding 0.05 atomic% of the adhesion improving element.

[0105] [Experiment 12]

In Example 1 above, after forming an adhesive Cu layer with the V, Zr, Re, Ru, Hf or Ga content adjusted to 50 nm on the surface of the TaN layer (the remainder being Cu and inevitable impurities), pure Cu The layer was formed by DC magnetron sputtering to a thickness of 200 nm to obtain a laminate.

[0106] Regarding Ga, the composition contained in the adhesive Cu layer was controlled by the procedure of Experimental Example 11 above.

[0107] With respect to the obtained laminate, the adhesion of the CuN layer to the TaN layer was measured under the same conditions as in Experimental Example 1. Figure 9 shows the relationship between the content of adhesion improving elements and the adhesion Cu layer determined by the MELT method. In Figure 9, mouth is V, · is Zr, ○ is Re, ♦ is Ru, ◊ appl

Is Hf, country is Ga, △ is Os, ▲ is T1 result.

[0108] As is apparent from FIG. 9, even when a pure Cu layer is formed on the surface of the adhesive Cu layer, the adhesive Cu layer adheres to the TaN layer as the amount of the adhesion improving element contained in the adhesive Cu layer increases. The adhesion strength of becomes higher. However, even if the adhesion improving element is contained in an amount exceeding 3 atomic%, the adhesion improving effect tends to be saturated.

[0109] Although the invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

[0110] This application is a Japanese patent application filed on November 28, 2006 (Japanese Patent Application 2006).

— 320572) and Japanese patent applications filed October 12, 2007 (Japanese Patent Application 2007)

— 267180), which is incorporated by reference in its entirety. [0111] Also, all references cited herein are incorporated as a whole.

Industrial applicability

[0112] According to the present invention, the force to appropriately adjust the component composition of the wiring body portion of the Cu wiring, and, when the wiring body portion of the Cu wiring is pure Cu, between the barrier layer made of pure Cu and TaN, Since an intermediate layer with an appropriately adjusted component composition is interposed! /, The adhesion between the wiring body and the barrier layer can be improved. As a result, no voids are generated between the wiring body and the barrier layer, and the reliability of the Cu wiring can be improved. However, according to the present invention, even when the width of the wiring groove or the interlayer connection path is narrow, the Cu-based wiring material is formed so as to cover the wiring groove or the interlayer connection path, and then heated or necessary. By further applying pressure accordingly, Cu-based wiring material can be embedded in wiring grooves and interlayer connection paths that do not impair the adhesion between the NOR layer and the wiring body.

Claims

Claims [1] A Cu spring embedded in a wiring groove or interlayer connection path formed in an insulating film on a semiconductor substrate, wherein the Cu wiring is (1) formed on the wiring groove side or interlayer connection path side And (1) one or more elements selected from the group consisting of Pt, In, Ti, Nb, B, Fe, V, Zr, Hf, Ga, Tl, Ru, Re, and Os. Consisting of 0.05 to 3.0 atomic% of Cu wiring itself and the Cu wiring of the semiconductor device. [2] A Cu spring embedded in a wiring groove or an interlayer connection formed in an insulating film on a semiconductor substrate, wherein the Cu wiring is

(1) a barrier layer made of TaN formed on the wiring trench side or interlayer connection path side;

(2) A wiring body made of pure Cu,

(3) formed between and in contact with the barrier layer and the wiring body, and Pt, In, Ti, Nb, B, Fe, V, Zr, Hf, Ga, Tl, Ru, Re and It is composed of an intermediate layer made of Cu containing 0.05 to 3.0 atomic percent of one or more elements selected from the group consisting of Os in total.

V, Cu wiring for semiconductor devices.

3. The Cu wiring according to claim 2, wherein the intermediate layer has a thickness of 10 to 50 nm.

[4] The wiring groove or the interlayer connection path according to any one of claims 1 to 3, wherein a width is 0.15 m or less and a ratio of depth to the width (depth / width) is 1 or more. Cu wiring described.

[5] forming a TaN layer on the surface of the wiring groove or interlayer connection path formed in the insulating film on the semiconductor substrate;

A total of one or more elements selected from the group consisting of Pt, In, Ti, Nb, B, Fe, V, Zr, Hf, Ga, Tl, Ru, Re, and Os are formed on the surface of this TaN layer by sputtering. 0.05-3.0 A method for manufacturing a Cu wiring of a semiconductor device, including a step of forming a Cu layer containing atomic percent.

[6] The wiring groove or the interlayer connection path has a width of 0.15 m or less, a ratio of depth to this width (depth / width) of 1 or more, and after the Cu layer is formed 6. The manufacturing method according to claim 5, wherein the Cu layer is pushed into the TaN layer-attached wiring groove or the interlayer connection path by heating.

[7] The wiring groove or the interlayer connection path has a width of 0.15 m or less, a ratio of depth to this width (depth / width) of 1 or more, and after the Cu layer is formed, 6. The manufacturing method according to claim 5, wherein the Cu layer is pushed into the wiring groove with the TaN layer or the interlayer connection path by heating and pressing.

[8] forming a TaN layer on the surface of the wiring groove or interlayer connection formed in the insulating film on the semiconductor substrate;

A total of one or more elements selected from the group consisting of Pt, In, Ti, Nb, B, Fe, V, Zr, Hf, Ga, Tl, Ru, Re, and Os are formed on the surface of this TaN layer by sputtering. 0.05-3.0. Forming a Cu layer containing 0 atomic%;

A method of manufacturing a Cu wiring of a semiconductor device including a step of forming a pure Cu layer on the surface of the Cu layer.

[9] The wiring groove or the interlayer connection path has a width of 0.15 m or less, a ratio of depth to the width (depth / width) of 1 or more, and after the pure Cu layer is formed The manufacturing method according to claim 8, wherein the pure Cu layer is pushed into the wiring groove with Cu layer or the interlayer connection path by heating.

Yes

[10] The wiring groove or the interlayer connection path has a width of 0.15 m or less, a ratio of depth to the width (depth / width) of 1 or more, and after the pure Cu layer is formed 9. The manufacturing method according to claim 8, wherein the pure Cu layer is pushed into the wiring groove with the Cu layer or the interlayer connection path by heating and pressing.