JP2945886B2 - Manufacturing method of wiring structure for semiconductor integrated circuit device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an Al wiring structure preferably applied to a semiconductor circuit device.

[0002]

2. Description of the Related Art Conventionally, in electronic devices and integrated circuits using semiconductors, aluminum (A) is mainly used for electrodes and wiring.
l) Or Al-Si or the like has been used. Where A
1 is inexpensive, has high electrical conductivity, and a dense oxide film is formed on the surface, so that the inside is chemically protected and stabilized, and the adhesion to Si is good. Has the advantage of

[0003] By the way, as the degree of integration of integrated circuits such as LSIs has increased, and fine wiring and multi-layer wiring have become particularly necessary in recent years. Severe demands are being made. Along with miniaturization due to an increase in the degree of integration, the surface of LSIs and the like has become increasingly uneven due to oxidation, diffusion, thin film deposition, etching, and the like. For example, an electrode or a wiring metal must be deposited on a stepped surface without disconnection or deposited in a via hole having a small diameter and a large diameter. 4Mbit or
In a 16 Mbit DRAM (dynamic RAM) or the like, the aspect ratio (via hole depth / via hole diameter) of a via hole on which a metal such as Al must be deposited is 1.0 or more, and the via hole diameter itself is 1 μm or less. Therefore,
A technique that can deposit Al even in a via hole having a large aspect ratio is required.

In addition, it is necessary to fill the via holes and deposit Al for wiring on the insulating film.
Moreover, this deposited film must be of very good quality.

[0005] The formation of such a deposited film cannot meet the above-mentioned requirements by a conventional sputtering method.

[0006] In the sputtering method, the film thickness at the step portion and the side wall of the insulating film becomes extremely thin.
This will significantly reduce the reliability of I.

[0007] Even with the bias sputtering method, there are problems with charged particle damage and limitations on the deposition rate.

[0008] Apart from this, various types of CVD (Chemic
al Vapor Deposition) method has been proposed.
Since CVD and optical CVD have a reaction in the gas phase, the surface covering property for unevenness on the substrate surface is relatively good. However, carbon atoms contained in the source gas molecules are taken into the film, and in particular, in plasma CVD, there is damage by charged particles (so-called plasma damage) as in the case of the sputtering method.

Therefore, since a film grows mainly by a surface reaction on the surface of the substrate, if a thermal CVD method is used, which has good surface covering properties for irregularities such as steps on the surface, deposition in via holes is likely to occur, and the steps in the vias are likely to occur. Can be expected to be avoided.

For this reason, various thermal CVD methods have been studied as a method of forming an Al film. For example, a method is known in which organic aluminum is dispersed in a carrier gas, transported to a heated substrate, and a film is formed by thermally decomposing gas molecules on the substrate. The method is used. For example, Jo
In the example shown in the urnal of Electrochemical Society Vol. 131, p. 2175 (1984), triisobutylaluminum (iC ₄ H ₉ ) ₃ Al (TIBA) was used as the organoaluminum gas, the deposition temperature was 260 ° C., and the reaction tube pressure was 0.5 torr. To form a film,
A film of 3.4 μΩcm is formed.

However, in this method, the surface flatness of Al is poor, and the Al in the via hole is improper because it does not become dense (see FIG. 10A).
In FIG. 10A, 90 is a single crystal Si substrate, 91 is an insulating film made of SiO ₂ , and 92 is a deposited film of Al.

JP-A-63-33569 describes a method of forming a film by heating organic aluminum in the vicinity of a substrate. In this method, Al can be selectively deposited by CVD only on the metal or semiconductor surface from which the natural oxide film on the surface has been removed. In this case TIBA
It is necessary to remove natural oxide film on the surface of the substrate before introducing. It is described that Al is deposited on an oxide film as a sputtering method after filling a via hole.
However, also in this method, since the surface smoothness of Al in the via hole, which is a major premise, is not sufficient, the resistivity is increased due to the interface between the Al film formed by the CVD method and the Al film formed by the sputtering method (see FIG. )). 92 in FIG.
Reference numeral -1 denotes a selectively deposited film of Al by a CVD method, 92-2 denotes an Al deposited film by a sputtering method, and 92-3 denotes a cause of deterioration of characteristics such as impurities at an interface. In this method, the CVD device is selectively deposited in via holes and then transferred to the sputtering device to form Al on the oxide film, so that the wafer is exposed to the air during the deposition. A high resistance layer is formed at the interface of the deposited film, which causes an increase in contact resistance. It is considered possible to reduce the formation of the high-resistance layer at the interface by connecting the CVD device and the sputtering device in a vacuum space, but the device becomes complicated,
The maintenance and maintenance are very troublesome, which is extremely inconvenient as a practical device.

There is also a disadvantage that the throughput is not improved because essentially two devices are used. In addition, it is necessary to heat the gas, and there is a restriction that the heating must be performed near the substrate, and it is difficult to determine how close the substrate must be heated.
There is also a problem that the place where the heater is placed is limited.

Further, the second edition of the Electrochemical Society Japan Chapter 2 Symposium (July 7, 1989)
The page proposes a device that uses TIBA and raises the gas temperature of TIBA higher than the substrate temperature according to the double-wall CVD method. This method is considered to be merely a modification of the above-mentioned Japanese Patent Application Laid-Open No. 63-33569. With this method, Al can be selectively grown only on a metal or a semiconductor, but it is difficult to accurately control the difference between the gas temperature and the substrate surface temperature. There is a disadvantage that it does not. That is, if these are to be controlled, the apparatus is complicated, and a single-wafer processing type in which deposition can be performed on only one wafer in one deposition process has to be performed. In addition, a film that cannot be said to be of high quality can be obtained only at a deposition rate of at most 500 Å / min, but the throughput required for mass production cannot be realized. In addition, even if the film is formed by this method, it is not sufficient to satisfy the above-mentioned requirements, for example, if it is not thickened to a certain degree, it will not be a uniform continuous film, the flatness of the film is poor, and the selectivity of Al selective growth cannot be maintained for a very long time. .

In the case where trimethylaluminum (TMA) is used as another organic metal, Al deposition by using plasma or light has been attempted. However, since plasma or light is used, the apparatus becomes complicated. In addition, since the apparatus is a single-wafer apparatus, there is still room for improvement to sufficiently improve the throughput.

As described above, the conventional method does not always cause the selective growth of Al, and even if it is possible, there is a problem in the flatness and purity of the Al film. Deposited in the via hole,
There is a problem in continuity between Al and Al on the insulating film. Also, the film forming method is not an advantageous method as a semiconductor integrated circuit manufacturing technique which requires low-cost manufacturing that is complicated and difficult to control.

As described above, a method for forming an Al wiring which is continuous in the via hole and on the insulating film and has excellent denseness and flatness at a low cost and reliably is not realized.

[0018]

SUMMARY OF THE INVENTION As described above, in the technical field of a semiconductor device in which higher integration is desired in recent years, in order to provide a highly integrated and higher performance semiconductor device at a low cost. Had a lot of room for improvement.

The present invention has been made in view of the above-mentioned technical problems, and firstly, in the same reaction space, the denseness and flatness of Al in a via hole are enhanced, and further, the Al is formed on a pure insulating film. Another object of the present invention is to provide a method of manufacturing an aluminum wiring structure sufficiently excellent in three-dimensional wiring by depositing high-quality Al continuously from a via hole.

A further object of the present invention is to provide a semiconductor integrated circuit device having an aluminum wiring structure excellent in denseness and flatness.

[0021]

In order to achieve the above object, a method of manufacturing a wiring structure for a semiconductor integrated circuit device according to the present invention is directed to a method of manufacturing a substrate having an insulating film provided with an opening by CV.
Disposing in a D apparatus, maintaining the temperature of the substrate in the range of not less than the decomposition temperature of the alkyl aluminum hydride and not more than 450 ° C., and supplying alkyl aluminum hydride gas and hydrogen gas onto the substrate to convert aluminum. Forming the hole in the hole, modifying the surface of the insulating film having aluminum formed in the hole, and modifying the substrate to a temperature not lower than the decomposition temperature of alkyl aluminum hydride and not higher than 450 ° C. Maintaining the temperature, supplying a gas of alkyl aluminum hydride and hydrogen gas onto the substrate to form an aluminum film on the surface-modified insulating film and on the aluminum in the opening. It is characterized by having.

Preferably, the aluminum film contains silicon.

Further, according to the method of manufacturing a wiring structure for a semiconductor integrated circuit device according to the present invention, an insulating film is provided on a base, and a conductor is filled in an opening provided in the insulating film. Is flattened, and a method for manufacturing a wiring structure for a semiconductor integrated circuit device having a wiring structure in which a surface of the base under the opening and a conductive film provided on the insulating film are electrically connected. Disposing a substrate having an insulating film provided with the opening in a CVD apparatus, maintaining the temperature of the substrate in a range not lower than the decomposition temperature of alkyl aluminum hydride and not higher than 450 ° C., and using a gas of alkyl aluminum hydride. Supplying single crystal aluminum in the opening by supplying hydrogen gas and hydrogen gas onto the substrate; and modifying the surface of the insulating film having the single crystal aluminum formed in the opening. And characterized by having a step of forming the conductive film on the surface modified the insulating film and on the single-crystal aluminum in said opening.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, when manufacturing a wiring structure for a semiconductor integrated circuit device, a substrate having an insulating film provided with an opening is disposed in a CVD apparatus. Above the decomposition temperature and 4
The temperature of the substrate is maintained within the range of 50 ° C. or less, and a gas of alkyl aluminum hydride and hydrogen gas are supplied onto the substrate to form aluminum in the opening. Next, the surface of the insulating film in which aluminum is formed in the opening is surface-modified. Then, the temperature of the substrate is maintained within the range of not less than the decomposition temperature of the alkyl aluminum hydride and not more than 450 ° C., and the gas of the alkyl aluminum hydride and the hydrogen gas are supplied onto the substrate, and the surface of the surface-modified insulating film is And forming an aluminum film on the aluminum in the opening. The aluminum film continuously formed on the aluminum in the opening and on the insulating film realizes an excellent wiring structure of the semiconductor integrated circuit device. In particular, the aluminum filled in the opening can be formed as single crystal aluminum, and the aluminum film can contain silicon.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a method of forming a deposited film using an organic metal will be outlined.

The decomposition reaction of the organic metal and the deposition reaction of the thin film greatly vary depending on the conditions of the kind of the metal atom, the kind of the alkyl bonded to the metal atom, the means for causing the decomposition reaction, the atmosphere gas and the like.

For example, in the case of MR ₃ (M: Group III metal, R: alkyl group), trimethylgallium

[0028]

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Is a radical cleavage in which the Ga—CH ₃ bond is cleaved by thermal decomposition.

[0030]

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In thermal decomposition, β

[0032]

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And C ₂ H ₄ . Also, triethyl aluminum with the same ethyl group

[0034]

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Is a radical decomposition in which Al—C ₂ H ₅ bonds are broken in thermal decomposition. But iC ₄ H ₉ bound isotributyl aluminum

[0036]

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Escapes from β.

Trimethylaluminum (TMA) comprising CH ₃ groups and Al has a dimer structure at room temperature.

[0039]

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Thermal decomposition is a radical decomposition in which Al—CH ₃ groups are cleaved. At a low temperature of 150 ° C. or less, it reacts with the atmosphere H ₂ to produce CH ₄ , and finally produces Al I do. However, at a high temperature of about 300 ° C. or more, even if H ₂ is present in the atmosphere, the CH ₃ group extracts H from the TMA molecule, and eventually A
An l-C compound results.

In the case of TMA, in a limited region where power is applied in a light or H ₂ atmosphere high-frequency (approximately 13.56 MHz) plasma, C ₂ H _{6 is} coupled by coupling of CH ₃ between two Al. Occurs.

The point is that the simplest alkyl group, CH ₃
Group, even organometallic consisting C ₂ H ₅ group or iC ₄ H ₉ group and Al or Ga, the reaction form the type of the type and the metal atom of the alkyl group, differs by the excitation decomposition means, a metal atom from an organic metal In order to deposit on the desired substrate, the decomposition reaction must be very tightly controlled. For example, triisobutylaluminum

[0043]

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In the case of depositing Al, the conventional low pressure CVD method mainly based on a thermal reaction causes irregularities on the order of μm on the surface, resulting in poor surface morphology. In addition, hillock generation due to heat treatment, Si diffusion at the interface between Al and Si
Since the Si surface was roughened and the migration resistance was poor, it was difficult to use it for a commercial-level VLSI process.

As described in detail above, the general property that the chemical properties of an organic metal greatly changes depending on the type and combination of organic substituents attached to the metal element, and therefore, in the CVD method using an organic metal, the deposited film cannot be formed. The setting of conditions becomes complicated.

Furthermore, if this is applied to a highly integrated circuit such as a DRAM of 4 Mbit or more, a deposited film (wiring) which cannot be used at all even if the film type condition setting is slightly changed.

In this case, it is needless to say that an extremely high quality deposited film can be formed. However, the conditions for forming the film are not so limited as to complicate the apparatus, but are in a relatively versatile range. It must be a method of forming a deposited film.

Therefore, the present inventors prepared many organic metals with the aim of finding a condition exceeding a level applicable to highly integrated circuits, and prepared a reaction gas, a carrier gas, a substrate temperature, and a reaction state of a gas. Numerous experiments with various changes were conducted and examined.

As a result, attention was paid to using alkylaluminum hydride as a raw material gas as a parameter capable of providing film forming conditions with high versatility. As a result of further study, it was found that suitable film forming conditions applicable to highly integrated circuits are as follows.

Alkyl aluminum hydride as source gas, H ₂ as reaction gas, electron donating surface as substrate
A substrate having (A) and a non-electron donating surface (B), wherein the temperature of the electron donating surface (A) as a substrate temperature is not lower than the decomposition temperature of alkyl aluminum hydride and not higher than 450 ° C. According to such a film forming raw material, first, Al having excellent surface flatness and denseness can be deposited in the via hole.

In the present invention, dimethyl aluminum hydride (D) is used as the alkyl aluminum hydride.
(MAH) is a substance known as an alkyl metal.However, what kind of reaction film forms an Al thin film cannot be predicted without forming a deposited film under all conditions. Met. For example, in the case where Al is deposited by photo-CVD of DMAH, the surface morphology is inferior, the resistance value is several μΩ to 10 μΩ · cm, which is larger than the bulk value (2.7 μΩ · cm), and the film quality is inferior.

On the other hand, in the present invention, a CVD method is used to selectively deposit a high-quality Al or Al-Si film as a conductive deposition film on a substrate.

That is, dimethyl aluminum hydride (DMAH) which is an organic metal is used as a source gas containing at least one atom serving as a constituent element of the deposited film.

[0054]

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Or monomethyl aluminum hydride (MMAH ₂ )

[0056]

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Then, using H ₂ as a reaction gas, an Al film is formed on the substrate by vapor phase growth using a mixed gas of these gases. Alternatively, dimethyl aluminum hydride
(DMAH) or monomethyl aluminum hydride (MMA
A gas containing H ₂ ) and Si as a source gas is used, and H ₂ is used as a reaction gas. An Al—Si film is formed on the substrate by vapor-phase growth using a mixed gas of these gases.

The substrate applicable to the present invention has a first substrate surface material for forming a surface on which Al is deposited and a second substrate surface material for forming a surface on which Al is not deposited. It is. As the first substrate surface material, a material having an electron donating property is used.

The electron donating property will be described in detail below.

The electron-donating material is a material in which free electrons are present in the substrate or whether free electrons are intentionally generated. For example, the electron-donating material exchanges electrons with raw material gas molecules attached on the surface of the substrate. A material having a surface where a chemical reaction is promoted. For example, metals and semiconductors generally correspond to this. Also included are those in which a thin oxide film exists on a metal or semiconductor surface. This is because a chemical reaction occurs between the substrate and the attached raw material molecules by electron transfer.

More specifically, semiconductors such as single crystal silicon, polycrystalline silicon, and amorphous silicon, and a combination of Ga, In, and Al as Group III elements and P, As, and N as Group V elements. Binary, ternary, or quaternary III-V compound semiconductors, or metals, alloys, silicides, etc., such as tungsten, molybdenum, tantalum, tungsten silicide, titanium silicide, aluminum, aluminum silicon, titanium aluminum, titanium It contains nitride, copper, aluminum silicon copper, aluminum palladium, titanium, molybdenum silicide, tantalum silicide, and the like.

On the other hand, as a material forming a surface on which Al or Al-Si is not selectively deposited, that is, as a non-electron donating material, silicon oxide by thermal oxidation, CVD, etc., BSG, PSG, BPSG, etc. Glass or oxide film, thermal nitride film,
It is a silicon nitride film by plasma CVD, low pressure CVD, ECR-CVD or the like.

On the substrate having such a structure, Al is deposited only by a simple thermal reaction in the reaction system between the source gas and H ₂ . For example the thermal reaction is essentially in the reaction system between DMAH and H _2, in the range of the substrate temperature 160 ° C. to 450 ° C.

[0064]

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According to the above reaction, it has been found that when a gas containing Al or Si is added only to the surface having the electron donating material, Al—Si is deposited.

When depositing pure Al, DMAH and H ₂ are used, and when depositing Al-Si, DMAH, Si ₂ H ₆ and H ₂ are used.

Even when MMAH is used instead of DMAH, Al or Al-Si is deposited on the surface having the electron donating material.

Since MMAH ₂ has a vapor pressure as low as 0.01 to 0.1 Torr at room temperature, it is relatively difficult to transport a large amount of raw material, and the deposition rate is several hundred Å / min, which is the upper limit in the present invention which satisfies the aforementioned requirements. It is most desirable to use DMAH, preferably having a vapor pressure of 1 Torr at room temperature.

[0069] Figure 1 (a) ~ (e) is, DMAH and H ₂ or DMAH
And is a schematic diagram showing how selective growth if using Si ₂ H ₆ and H _2.

FIG. 1 (a) is a diagram schematically showing a cross section of a substrate before an Al or Al-Si deposited film is formed. 90 is a substrate made of an electron donating material, for example, a Si wafer. Reference numeral 91 denotes a thin film made of a non-electron donating material, for example, a thermally oxidized SiO ₂ film or a CVDBSG film.

The mixed substrate containing DMAH, Si ₂ H ₆ as the raw material gas and H ₂ as the reaction gas is at or above the decomposition temperature of DMAH and
When supplied on the substrate 1 heated within a temperature range of 450 ° C. or less, Al-Si is deposited on the substrate 90, and a continuous film of Al-Si is formed as shown in FIG. 1 (b). .

When the deposition of Al—Si is continued, the Al—Si film passes through the state shown in FIG. 1C, and as shown in FIG.
Grow up to the top level. When further grown, as shown in FIG. 1 (e), the Al-Si film can grow up to 5000 ° with almost no lateral growth. This is the most characteristic feature of the deposited film using DMAH and H ₂ or DMAH and H ₂ and Si ₂ H _6, or a Ikagani capable of forming a high quality film under good selectivity is I can understand.

As a result of analysis by Auger electron spectroscopy or photoelectron spectroscopy, no impurities such as carbon and oxygen are mixed in this film.

The resistivity of the deposited film thus formed is 2.7 to 3.0 μΩ · cm at room temperature at a film thickness of 400 °, which is almost equal to the resistivity of the Al bulk, and is a continuous and flat film.
Even if the film thickness is 1 μm, the resistivity is still approximately 2.7 to 3.0 μΩ · cm at room temperature, and a sufficiently dense film can be formed even with a thick film. The reflectance in the visible light wavelength region is also approximately 80%, and a thin film having excellent surface flatness can be deposited.

In the multilayer wiring process in the VLSI,
As shown in FIG. 1D, a technique for selectively embedding a via hole with high-quality Al or Al-Si is essential. Further FIG.
After the selective deposition as shown in (d), in the same reaction vessel, as shown in FIG.
Non-electron donating materials on l-Si, eg thermal oxidation
If Al or Al-Si can be deposited on the SiO ₂ film or the CVD BSG film, a highly reliable multilayer wiring process that does not cause disconnection of wiring at a stepped portion can be realized.

As described in detail above, in the selective growth of an alkyl aluminum hydride on an electron-donating surface at a decomposition temperature of 450 ° C. or less using alkyl aluminum hydride and H ₂ , the selectivity of the Al film is extremely excellent. In addition, the formation of the Al film on the thin film 91 requires some contrivance. In view of this, by modifying the surface of the non-electron donating surface, an Al film is formed on the non-electron donating surface that could not be deposited due to its selectivity before the surface modification. It becomes possible.

Of course, if such a method is used, the following points in combination with the sputtering method, ie, CVD
After the process, when transferring the wafer to another sputtering device,
Since the wafer is inevitably exposed to the atmosphere, a high-resistance layer containing oxygen or the like is formed at the interface between the selectively grown Al film and the non-selectively formed Al film, causing an increase in contact resistance and low-resistance wiring. Needless to say, it is possible to improve the point that it is difficult to achieve the above.

Further, according to the present invention, Al or Al-Si as shown in FIG. 1F can be deposited by one CVD apparatus.

The operation of the present invention is as follows. First, using DMAH and H ₂ or DMAH and Si ₂ H ₆ and H ₂ , FIG.
As shown in (a) to (e), deposition is performed to fill the via hole. After that, the non-electron donating surface is effectively modified into a surface with an electron donating material, and the electron donating material is Al or
Al or Al-Si is uniformly deposited on the Al-Si surface and on the non-electron-donating material which has effectively become an electron-donating material by surface modification. Surface modification refers to a state where free electrons are present even on a non-electron donating surface and can contribute to the surface reaction. For example, on SiO ₂ , there is a method of irradiating light having energy larger than the forbidden band width of SiO ₂ to form free electrons on the non-electron donating surface. In addition, there is a method in which electrons are charged by electron beam irradiation accelerated appropriately, or free electrons are generated. In addition, it is also possible to cut off, for example, Si—O bonds existing on the surface by ion irradiation or plasma treatment and generate electrons by unbonded bonds.

Further, an electron donating metal such as Ti
There is a method of forming an ultra-thin film or nucleus of Si or Si, and effectively modifying the surface to an electron-donating surface.

Of course, Al or A
An ultra-thin film or nucleus of l-Si may be formed to effectively modify the electron donating surface. For example while supplying DMAH and H _2, when a plasma is generated H ₂ and DMAH in the plasma is excited or decomposed, nucleus or extremely thin film is deposited to a non-electron donative surface. In this case, H ₂ and DMAH
Are excited or decomposed by the plasma to become non-electron-donating molecules, and the source molecules (excited or decomposed DMAH molecular species, and excited or ionized H ₂ molecules or H atoms) themselves without the electrons contributing to the reaction on the substrate surface It is thought that the reaction proceeds. The non-electron donating surface is surface modified,
When the deposition of Al starts, Al is continuously deposited.

In some of the above methods, a nucleus or an ultrathin film other than Al or Al—Si is not preferable for surface modification because it is difficult to maintain the crystallinity of the selectively deposited Al film. .

The method of generating an electron beam or an ion beam has a drawback that the apparatus configuration becomes complicated. In addition, when irradiated with electron beams or ions, the quality of the Al film deposited non-selectively after the surface modification is not inferior to that of the Al film deposited selectively, but the charged particles may damage the wafer during the surface modification. There is a danger of getting lost. The Al wiring process in LSI is generally performed, for example, after the formation of the MOSFET, which causes charged particle damage to the gate oxide film of the MOSFET due to electron beam irradiation and ion irradiation, resulting in characteristic deterioration such as threshold fluctuation of the MOSFET. .

In the case of performing surface modification using plasma, it is necessary to use a method that does not cause damage to charged particles.

FIG. 2 is a schematic view showing an example of a deposited film forming apparatus to which the present invention can be applied.

Here, reference numeral 1 denotes a substrate for forming an Al-Si film. The substrate 1 is placed on a substrate holder 3 provided inside a reaction tube 2 for forming a space for forming a deposited film which is substantially closed with respect to FIG. Quartz is preferred as a material constituting the reaction tube 2, but it may be made of metal. In this case, it is desirable to cool the reaction tube. The base holder 3 is made of metal, and is provided with a heater 4 so as to heat the mounted base. The temperature of the substrate can be controlled by controlling the heat generation temperature of the heater 4.

The gas supply system is configured as follows.

Reference numeral 5 denotes a gas mixer, which mixes the first raw material gas, the second raw material gas, and the reaction gas and supplies them to the reaction tube 2. Reference numeral 6 denotes a source gas vaporizer provided for vaporizing an organic metal as a first source gas.

Since the organic metal used in the present invention is liquid at room temperature, the carrier gas is converted into saturated vapor through the organic metal liquid in the vaporizer 6 and is introduced into the mixer 5.

The exhaust system is configured as follows.

Reference numeral 7 denotes a gate valve which is opened when exhausting a large amount of gas such as exhausting the inside of the reaction tube 2 before forming a deposited film. Reference numeral 8 denotes a slow leak valve, which is used when a small volume of gas is exhausted, for example, when adjusting the pressure inside the reaction tube 2 when forming a deposited film. Reference numeral 9 denotes an exhaust unit, which includes an exhaust pump such as a turbo molecular pump.

The transport system for the substrate 1 is configured as follows.

Reference numeral 10 denotes a substrate transfer chamber capable of accommodating the substrates before and after the formation of the deposited film. 12 is an exhaust unit for exhausting the transfer chamber,
It is composed of an exhaust pump such as a turbo molecular pump.

The valve 13 is opened only when the substrate 1 is transferred between the reaction chamber and the transfer space.

As shown in FIG. 2, in a gas generating chamber 6 for generating a first raw material gas, H ₂ or Ar (or another carrier gas) as a carrier gas is supplied to a liquid DMAH kept at room temperature. Bubbling with an inert gas)
Gaseous DMAH is produced and transported to mixer 5. H ₂ as a reaction gas is transported to the mixer 5 from another route. The flow rate of each gas is adjusted so that its partial pressure becomes a desired value.

As the first source gas, MMAH ₂ may be used, but DMAH which is sufficient for the vapor pressure to become 1 Torr at room temperature is most preferable. It may also be used by mixing DMAH and MMAH _2.

Further, as the second source gas for forming the Al—Si film, the gas containing Si may be Si ₂ H ₆ , SiH ₄ , Si
₃ H ₈ , Si (CH ₃ ) ₄ , SiCl ₄ , SiH ₂ Cl ₂ , and SiH ₃ Cl can be used. In particular, Si that is easily decomposed at low temperatures of 200 to 300 ° C
₂ H ₆ is most preferred. A gas such as Si ₂ H ₆ diluted with H ₂ or Ar is transported to the mixer 5 from a separate system from the DMAH and supplied to the reaction tube 2.

When a gas is used for the surface reforming, a gas containing Si or a gas containing Ti such as TiCl ₄ is transported to the mixer 5 from a separate system from the piping for the gas containing DMAH or Si, and transferred to the reaction vessel 2. There is a way to supply.

When depositing Al, DMAH and H ₂ , Al-Si
When a mixed gas containing DMAH, Si ₂ H ₆ and H ₂ is supplied onto the substrate 1 heated to a temperature range not lower than the decomposition temperature of DMAH and not higher than 450 ° C., the substrate 90 Al-S
i is precipitated, and as shown in FIG.
A continuous film of i is formed.

When the deposition of Al or Al-Si is continued under the above conditions, the Al or Al-Si film passes through the state shown in FIG. 1C, and as shown in FIG. Grow to the level. The selectively deposited film is a single crystal.

Here, the supply of DMAH and Si ₂ H ₆ is stopped, and A
Stop the deposition of 1 or Al-Si. Here, after performing the `` surface modification step '' in which the above-mentioned gas is introduced and a surface reaction is caused on the heated non-electron donating surface, DMAH is again formed.
By supplying Si ₂ H ₆ , Al or Al—Si is deposited in a shape as shown in FIG.

As described above, the substrate temperature is desirably not lower than the decomposition temperature of the raw material gas containing Al and not higher than 450 ° C. As described above, specifically, the substrate temperature is desirably 200 to 450 ° C. Is performed, the pressure in the reaction vessel is 10 ^{-3 to} 760 torr, and the partial pressure of DMAH is 1.5 × 10 of the pressure in the reaction vessel.
^{When -5 to} 1.3 × 10 ^-3 times, the deposition rate is 100 l / min to 800 l
/ Min, which is a sufficiently high deposition rate for Al-Si deposition technology for VLSI.

More preferably, the substrate temperature is from 270 ° C. to 350 ° C.
The Al-Si film deposited under these conditions has a strong orientation, and hillocks and spikes are generated on the Al-Si film on Si single crystal or Si polycrystal substrate even after heat treatment at 450 ° C for 1 hour. And a good quality Al-Si film. Further, such an Al-Si film is excellent in electromigration resistance.

In this case, the surface modification step is, in other words,
If TiCl_Four , Si_TwoH₆, SiH_Four, SiCl_Four, SiHCl_Three, SiH_TwoCl_Two Etc.
To provide a non-electron donating surface with an electron donating
It is also to form an ultra-thin film or nucleus of Ti, Si, etc.
TiCl above_Four, Si_TwoH₆, SiH_Four, SiCl _Four, SiHCl_Three, SiH_TwoCl_Two To Al
Alternatively, at the same substrate temperature as when Al-Si was deposited,^-Four~ 1tor
When supplied at a partial pressure of r, the non-electron donating surface
Becomes an electron-donating surface and can be deposited as shown in Fig. 1 (e).
It is. Electron donating metal electrode on non-electron donating surface
A thin film may be formed.

In the apparatus shown in FIG. 1, Al--Si can be deposited on only one substrate in one deposition.
Although a deposition rate of approximately 800 l / min can be obtained, there may be points to be improved if a large number of sheets are to be deposited in a short time.

As a deposition film forming apparatus for improving this point, there is a low pressure CVD apparatus capable of simultaneously loading a large number of wafers and depositing Al-Si. Al according to the invention
-Si deposition uses surface reactions on a heated electron-donating substrate surface and a surface-modified non-electron-donating surface,
By only substrate of adding the Si source gas DMAH and such as H ₂ and Si ₂ H ₆ as long as the hot wall type low pressure CVD method to be heated, including 0.5 to 2.0% of pure Al or Si A
l-Si can be deposited.

The pressure in the reaction tube is 0.05 to 760 Torr, preferably
0.1 to 0.8 Torr, the substrate temperature is 160 to 450 ° C., preferably 200 to 400 ° C., and the partial pressure of DMAH is 1 × 10 ^{−5 of the} pressure in the reaction tube.
× 1.3 × 10 ^-3 times, the partial pressure of Si ₂ H ₆ is 1 × 10
The range is ^-7 to 1 × 10 ^-4 times, and Al or Al-Si is deposited. TiCl ₂ , Si ₂ H ₆ , SiH ₄ , SiC
When l ₄ , SiHCl ₃ , and SiCl ₂ H ₂ are used, a large number of wafers can be simultaneously deposited using a low-pressure CVD apparatus.

FIG. 3 is a schematic view showing a deposited film forming apparatus to which the present invention can be applied.

Reference numeral 57 denotes a base for forming an Al or Al-Si film. 50 is an outer reaction tube made of quartz which forms a space for forming a deposited film substantially closed with respect to the surroundings, 51
Is a quartz inner reaction tube installed to separate the gas flow in the outer reaction tube 50, 54 is a metal flange for opening and closing the opening of the outer reaction tube 50, and the base 57 is an inner It is installed in a substrate holder 56 provided inside the reaction tube 51. Note that the base holder 56 is desirably made of quartz.

In this apparatus, the temperature of the substrate can be controlled by the heater 59. The pressure inside the reaction tube 50 can be controlled by an exhaust system connected via a gas exhaust port 53.

The source gas has a first gas system, a second gas system, a third gas system and a mixer (all not shown), as in the apparatus shown in FIG. The gas is introduced into the reaction tube 50 from the source gas introduction line 52. The raw material gas reacts on the surface of the substrate 57 when passing through the inside of the inner reaction tube 51 as shown by an arrow 58 in FIG. 3, and deposits Al-Si on the surface of the substrate. The gas after the reaction passes through a gap formed by the inner reaction tube 51 and the outer reaction tube 50, and is exhausted from the gas exhaust port 53.

When the base is taken in and out, the metal flange 54 is lowered together with the base holder 56 and the base 57 by an elevator (not shown), and is moved to a predetermined position to mount and remove the base.

By using such an apparatus to form a deposited film under the above-described conditions, a high-quality Al-Si film can be simultaneously formed on all wafers in the apparatus.

In the surface modification step, there is also a method using charged particles such as plasma using the deposited film forming apparatus shown in FIG.

FIG. 4 is a schematic view showing an example of a deposited film forming apparatus to which the present invention can be applied. 2 in that an electrode 16 is provided as plasma generating means.

The electrode 16 is used when generating plasma for performing surface modification. A high frequency power of about 13.6 MHz is applied to the electrode 16 from the power supply 14 to generate plasma.

[0117] When using a plasma can be used Ar or H ₂ plasma, hydrogen ions, is more of an existing H ₂ plasma reactive particles such as hydrogen radicals preferred.
Reaction tube pressure is 0.1 to 5 Torr, plasma power is 0.1 to 1 W / c
it is possible to surface modification in m ^3. Desirably, it is 0.2-0.5 W / cm ³ .

The above TiCl ₄ , Si ₂ H ₆ , SiH ₄ , SiCl ₄ , SiHCl ₃ ,
When SiH ₂ Cl ₂ is supplied at the same substrate temperature as that of Al or Al-Si deposition at a partial pressure of 10 ^{-4 to 1} Torr, the non-electron donating surface effectively becomes an electron donating surface, and FIG. The deposition as shown in e) is possible.

As a very thin film of a metal having an electron donating property, carbon is mixed into the non-electron donating surface by using DMAH + H ₂ , but a method of instantaneously increasing the substrate temperature to 450 ° C. or more is also available. It is possible.

FIG. 5 shows that the substrate temperature was set to 450 only during the surface modification step.
Instantaneous heating such that a temperature rise of, for example, 100 ° C./min or more is obtained from 100 ° C. to 550 ° C., DMAH and H ₂ are supplied, and Al-C
FIG. 2 is a schematic view of an apparatus capable of forming an extremely thin film or a nucleus. Portions having the same functions as those in FIG. 4 are denoted by the same reference numerals. Reference numeral 21 denotes a light transmission window, which is made of quartz glass. 22 is an instant heating lamp. Xe lamp, Hg-Xe lamp and W lamp are used. Although a laser or the like may be used, a lamp is preferable for uniform instantaneous heating.

The transfer of the substrate is performed in a direction perpendicular to the plane of the drawing (the transfer chamber is not shown).

In the surface modification step, using plasma
There is also a method in which a DMAH molecule or an H ₂ molecule is excitedly decomposed into electron donating molecules to form a nucleus or an extremely thin layer of Al or Al—Si on the surface of a non-electron donating substrate. FIG. 6 is a schematic diagram showing an example of a deposited film forming apparatus to which the present invention can be applied.

4 is different from FIG. 4 in that ground electrodes 16 'and 16 "are provided in addition to the excitation electrode 16 as a plasma generation electrode.
A high frequency power of Hz is applied to generate plasma. Since the excitation electrode 16 is sandwiched between the ground electrodes 16 'and 16 ", the lines of electric force from the excitation electrode 16 terminate at the ground electrodes 16 and 16', so that the plasma does not contact the substrate 1. The electron donating surface After selectively depositing Al or Al-Si on the electron donating surface on a substrate having a non-electron donating surface and DM
Plasma is generated while AH and H ₂ or DMAH, H ₂ and Si ₂ H ₆ are supplied. In plasma, DMAH is excited and decomposed into electron donating molecules, and forms Al or Al-Si nuclei or ultrathin films on non-electron donating surfaces. After the formation of the Al nucleus, the plasma is stopped and the deposition is continued.

Since the partial pressure of DMAH at the time of depositing Al is at most about 5 × 10 ^{−3 with} respect to the reaction gas H ₂ , the properties of the plasma are very similar to those of the H ₂ plasma. If the plasma power is large, DMAH is excited and decomposed more than necessary, and carbon is mixed into Al or Al-Si formed in the surface modification step. If the plasma power is too small, DMAH is not excited and decomposed, so that a nucleus or an ultrathin film of Al or Al-Si is not formed. When Ar is used as the carrier gas, Al or A formed in the surface modification step is used.
Since carbon is mixed into the nucleus of l-Si or the ultra-thin film, it is preferable to use H ₂ as the carrier gas. During the surface modification, the reaction tube pressure is 0.1 to 5 torr, the applied plasma power is 0.02 to 0.4 W / cm ^-3 in the apparatus shown in FIG. 6, and the surface modification time is 10 sec or more.

When the applied plasma power was about 0.02 W / cm ^-3 or less, no Al or Al-Si nucleus or an extremely thin film was formed, and no surface modification was possible. The plasma power for surface modification is desirably 0.02 to 0.06 w / cm- ³ . After modifying the non-electron donating surface, Al is non-selectively deposited on the electron donating surface and the non-electron donating surface. At this time, no carbon was detected at the interface between the selectively deposited Al or Al-Si and the non-selectively deposited Al or Al-Si interface.

After the surface modification step, the deposition may be continued without stopping the plasma. The quality of the Al or Al-Si film deposited with the plasma applied was almost the same as the film deposited without the application of the plasma. However, since the surface flatness is slightly inferior, it is desirable to apply the plasma only during the surface modification. In addition, the plasma power density applied during surface modification is
It is smaller than the plasma power used for D and reactive ion etching, and hardly deposits on the reaction tube surface.

In the apparatus shown in FIG. 6, 13.56 MHz is used for plasma generation.
Although a high-frequency power supply of the type described above was used, a discharge of a direct current or a commercial frequency or a microwave (for example, 2.45 GHz) may be used.

However, DC discharge has a disadvantage that an electrode must be provided in the reaction chamber. In the case of using a microwave, a waveguide is required, so that the device configuration becomes more complicated than in the case of 13.56 MHz in which only an external electrode is required.

Further, microwave plasma has the disadvantage that the electron temperature or electron density increases, the decomposition of alkyl aluminum hydride is easily promoted, and the range of optimal surface modification conditions is narrowed.

The film obtained by the Al or Al-Si film forming method according to the present invention is dense, has an extremely low content of impurities such as carbon, has a resistivity comparable to that of bulk, and has a high surface flatness. Have. Reduction of hillocks during heat treatment Improvement of electromigration resistance Reduction of alloy pits in contact area Improvement of wiring patterning property by improvement of surface smoothness Improvement of resistance in via hole and contact resistance Lower temperature of heat treatment during wiring process It has a great effect.

According to the method shown in the present invention, an electron-donating material and a non-electron-donating material are mixed and a deposited film is first selectively formed in a concave portion even on a substrate having irregularities of the order of μm or submicron. Thereafter, a uniform Al film can be formed on the entire surface of the substrate in the same film forming apparatus.

In the process of forming the multilayer wiring of the VLSI, the reduction in the thickness of the metal thin film in the uneven portion lowers the reliability of the wiring forming process.
According to the i-film deposition method, a highly reliable Al, Al-Si film can be formed without a decrease in film pressure or the like in the uneven portion.

In the conventional sputtering method, it is difficult to form a uniform film on the uneven portion. Therefore, it is necessary to provide a step of inclining the cross-section of the opening of the insulating film by a method such as reflow by high-temperature heat treatment. Was. However, providing an inclination to the opening requires an unnecessary area, and is a step that is compatible with the miniaturization technology.

According to the present invention, Al, Al-Si is buried in a via hole having a vertical cross section, and the Al film formed thereafter is excellent in flatness. As ideal as.

(Example 1) The procedure for forming an Al film is as follows.

Using the apparatus shown in FIG. 2, the inside of the reaction tube 2 is evacuated to approximately 1 × 10 ⁻⁸ Torr by the exhaust equipment 9. However, even if the degree of vacuum in the reaction tube 2 is lower than 1 × 10 ⁻⁸ Torr, Al is deposited.

After cleaning the Si wafer, the transfer chamber 10 is released to the atmospheric pressure, and the Si wafer is loaded into the transfer chamber. Transfer chamber is approximately 1 × 10
After evacuating to ⁻⁶ Torr, the gate valve 13 is opened and the wafer is mounted on the wafer holder 3.

After mounting the wafer on the wafer holder 3,
The gate valve 13 is closed, and the degree of vacuum in the reaction chamber 2 is approximately 1 × 10
Exhaust to ^-8 Torr.

In this embodiment, DMAH is supplied from the first gas line. Carrier gas DMAH line with H _2. The second gas line is used for H _2.

H ₂ is supplied from the second gas line, and the opening of the slow leak valve 8 is adjusted to set the pressure in the reaction tube 2 to a predetermined value. Typical pressure in this embodiment is approximately 1.5 Torr
And Thereafter, the heater 4 is energized to heat the wafer. After the wafer temperature reaches the specified temperature, DMH
AH is introduced into the reaction tube. The total pressure is about 1.5 Torr,
The DMAH partial pressure is approximately 1.5 × 10 ⁻⁴ Torr. DMAH to reaction tube 2
, Al is deposited.

After a predetermined deposition time has elapsed, the supply of DMAH is temporarily stopped. The Al film deposited in this process is 1A
1 film. The predetermined deposition time is a time until the thickness of the Al film on Si becomes equal to the thickness of SiO ₂ .

With the substrate temperature kept constant, TiCl ₄ is introduced into the reaction vessel 2 from the third gas line. The time to introduce TiCl ₄ is about 10 minutes. The step of introducing TiCl ₄ is the surface modification step. Stop the supply of TiCl ₄ and, again, DMAH
Supply. Al already deposited by DMAH supply
1 and on the SiO ₂ film. After a predetermined deposition time has elapsed, the supply of DMAH is stopped. The Al film deposited in this process is referred to as a second Al film.

[0143] In the temperature range of 160 ° C. -450 ° C. in the sample, in the first 1Al film deposition process, on the SiO ₂ Al is not deposited, the Al of the same thickness as SiO ₂ only the portion Si is exposed In the second Al film deposition step, the first Al film and the Si
Al is deposited on O ₂ at substantially the same deposition rate. Next, heating of the heater 4 is stopped, and the wafer is cooled. After the supply of H ₂ gas is stopped and the inside of the reaction vessel is evacuated, the wafer is transferred to a transfer chamber, and only the transfer chamber is set to atmospheric pressure, and then the wafer is taken out. The above is the outline of the Al film forming procedure.

Next, the preparation of a sample in this embodiment will be described.

[0145]

[Outside 1]

The film thickness is 7000 ° ± 500 ° and the refractive index is 1.
46. A photoresist is applied to the entire surface of the Si substrate,
A desired pattern is printed by an exposure machine. The pattern is
Various pores of 0.25 μm × 0.25 μm to 100 μm × 100 μm are formed. After developing the photoresist, the underlying SiO ₂ was etched by reactive ion etching (RIE) using the photoresist as a mask, thereby partially exposing the substrate Si. In this way, 0.25 μm × 0.25 μm to 100 μm ×
Samples with 100 μm SiO ₂ pores of various sizes
The samples were prepared, the substrate temperature was set in 13 ways, and Al was deposited on 10 samples at each substrate temperature according to the above-described procedure.

The first Al film deposition step, the surface modification step, the second
The conditions of the Al film deposition step are as follows.

At the time of the first Al film deposition step, the total pressure is 1.5 Torr DMAH partial pressure 1.5 × 10 ^-4 Torr At the time of the surface modification step, the TiCl ₄ partial pressure is 0.1 Torr At the time of the second Al film deposition step, the total pressure is 1.5 Torr DMAH partial pressure 1.5 × 10 ^-4 Torr.

Al deposited by changing the substrate temperature to 13 levels
The films were evaluated using various evaluation methods. The result is shown in FIG.
Shown in

In the above sample, in the temperature range of 160 ° C. to 450 ° C., in the first Al deposition step, Al was deposited only on the exposed portion of Si.
And selectively deposited in the same thickness as the O _2. This film was a single crystal. Further, in the second Al deposition step, Al was deposited at the same deposition rate on both the SiO ₂ surface and the Al film deposited in the first deposition step.

The Al film selected on Si and Si after the surface modification step
The Al film deposited on O ₂ did not differ in film quality such as resistivity, reflectance, and hillock generation density after the heat treatment step.

Further, no increase in resistance occurred at the interface between the first Al film and the second Al film.

The partial pressure of TiCl _{4 in the} surface modification step was set to 0.05 to 0.5.
Even when the pressure was changed to Torr, there was no difference between the deposition rate and the film quality of the Al film.

(Example 2) In the same procedure as in Example 1, at the time of the surface modification step, instead of TiCl ₄ , Si ₂ H ₆ was applied at a partial pressure of 0.1-0.1.
Introduced at 50 Torr, an Al film was deposited.

In the first Al deposition step, only the exposed Si
An Al film having the same thickness as SiO ₂ is selectively deposited, the substrate temperature during the surface modification step is 200 ° C. to 450 ° C., and the partial pressure of Si ₂ H _{6 is} 0.1 to 50.
At Torr, a second Al deposition step is performed on SiO ₂ and the first
Al was deposited at the same deposition rate on both Al films.

The film quality of the deposited Al film was as good as in Example 1.

(Example 3) In the same procedure as in Example 1, at the time of the surface modification step, instead of TiCl ₄ , instead of SiCl ₄ or SiHC,
l ₃ or SiH ₂ Cl ₂ is introduced at a partial pressure of 0.1 to 50 Torr, and Al
The film was deposited.

In the first Al deposition step, only SiO ₂
When the Al film having the same thickness as the above is selectively deposited and the substrate temperature during the surface modification step is 200 ° C. to 450 ° C., the partial pressure of SiCl ₄ , or SiHCl ₃ or SiH ₂ Cl ₂ is 0.1 to 50 Torr, A of 2
In the 1 deposition step, Al was deposited on both the SiO ₂ and the first Al film at the same deposition rate.

The quality of the deposited Al film was as good as in Example 1.

[0160] (Example 4) Example 1, Example 2, Example 3, instead of H ₂ carrier gas DMAH line Ar
Using the same procedure as in Example 1, Example 2, and Example 3.
Al was deposited on the Si substrate on which the SiO ₂ thin film was patterned. The method of manufacturing the base is the same as that of the first embodiment. The same results as in Examples 1, 2 and 3 were obtained for all the deposited Al films.

(Example 5) A substrate (samples 5-1 to 5-1) having the following structure was formed by using the low pressure CVD apparatus shown in FIG.
5-179), an Al film was formed.

Preparation of Sample 5-1 A thermally oxidized SiO ₂ film as a non-electron-donating second substrate surface material was formed on single-crystal silicon as an electron-donating first substrate surface material. Then, patterning was performed by a photolithography process as shown in Example 1 to partially expose the single crystal silicon surface.

At this time, the thickness of the thermally oxidized SiO ₂ film was 7000 °, and the size of the exposed portion of single crystal silicon, that is, the opening was 3 μm × 3 μm.
m. Thus, sample 5-1 was prepared (hereinafter, such a sample was referred to as “thermally oxidized SiO ₂ (hereinafter, T-SiO _2)).
Abbreviation) / single-crystal silicon ”).

Preparation of Samples 5-2 to 5-179 Sample 5-2 is an oxide film formed by normal pressure CVD (hereinafter referred to as an oxide film).
Abbreviated as SiO ₂₎ / monocrystalline silicon samples 5-3 abbreviated as oxide film (hereinafter BSG boron doped was deposited by atmospheric pressure CVD) / monocrystalline silicon, Sample 5-4 a phosphorus-doped was formed by normal pressure CVD Oxide film (hereinafter abbreviated as PSG) / single-crystal silicon, sample 5-5 is phosphorus- and boron-doped oxide film (hereinafter abbreviated as BSPG) / single-crystal silicon, sample 5-
6 is a nitride film (P-SiN
Abbreviated) / single-crystal silicon, sample 5-7 is a thermal nitride film (abbreviated as T-SiN) / single-crystal silicon, sample 5-8
Is a nitride film (hereinafter abbreviated as LP-SiN) / single-crystal silicon formed by low-pressure DCVD, and Sample 5-9 is a nitride film (hereinafter abbreviated as ECR-SiN) / single-crystal silicon formed by an ECR apparatus. Further, samples 5-11 to 5-17 shown in Tables 1, 2 and 3 were obtained by combining the first substrate surface material having an electron donating property and the second substrate surface material having a non-electron donating property.
9 was created. In Table 1, Table 2 and Table 3, as the first substrate surface material, single crystal silicon (single crystal Si), polycrystal silicon (polycrystal Si), amorphous silicon (amorphous Si), tungsten (W), Molybdenum (Mo), tantalum (Ta), tungsten silicide (WSi), titanium silicide (TiSi), aluminum (Al), aluminum silicon (Al-Si), titanium aluminum (Al-Ti), titanium nitride (Ti-N ), Copper (Cu),
Aluminum silicon copper (Al-Si-Cu), aluminum palladium (Al-Pd), titanium (Ti), molybdenum silicide (Mo-Si), and tantalum silicide (Ta-Si) were used. These samples were put into a low pressure CVD apparatus, and an Al film was formed in the same batch.

Reaction tube pressure 0.3 Torr DMAH partial pressure 3 × 10 ^-5 Torr Substrate temperature 300 ° C. Surface modification step, TiCl ₄ partial pressure 0.4 Torr Reaction tube pressure during the first Al film formation step Al was deposited under the condition of a 0.3 Torr DMAH partial pressure of 3 × 10 ⁻⁵ Torr and a substrate temperature of 300 ° C.

Under the above conditions, in the first Al film deposition step, no Al was deposited on the non-electron donating surface, and only the exposed portion of the electron donating surface had the same thickness of A as the non-electron donating film.
1 was deposited, and in the second Al film deposition step after the surface modification step, Al was deposited on the first Al film and on the non-electron donating surface at almost the same deposition rate.

The film quality of the deposited Al film was the same as that of the substrate temperature of 300 ° C. shown in Example 1, and was very good.

[0168]

[Table 1]

[0169]

[Table 2]

[0170]

[Table 3]

(Example 6) In the same procedure as in Example 5, at the time of the surface modification step, instead of TiCl ₄ , Si ₂ H ₆ was applied at a partial pressure of 0.1 to 0.1%.
Introduced at 50 Torr, an Al film was deposited.

When the substrate temperature during the surface modification step is 200 to 400
In a second Al deposition step, at a temperature of 0 ° C. and a partial pressure of Si ₂ H _{6 of} 0.1 to 50 Torr, Al was deposited at the same deposition rate on both the first Al film and on the non-electron donating material. The film quality of the deposited Al film was good as in the case of Example 1.

(Embodiment 7) In the same procedure as in Embodiment 5, at the time of the surface modification step, instead of TiCl ₄ , instead of SiCl ₄ or SiHC,
l ₃ or SiH ₂ Cl ₂ is introduced at a partial pressure of 0.1 to 50 Torr, and Al
The film was deposited.

In the first Al deposition step, an Al film having the same thickness as the non-electron donating material was selectively deposited only on the exposed portion of the electron donating material, and the substrate temperature during the surface modification step was 200 ° C. ~ 45
0 ° C, partial pressure of SiCl ₄ , or SiHCl ₃ or SiH ₂ Cl ₂
At 0.1 to 50 Torr, Al was deposited at the same deposition rate both on the non-electron donating material and on the first Al film in the second Al deposition step.

The film quality of the deposited Al film was very good as in the case of Example 1.

(Embodiment 8) In the same procedure as in Embodiment 1, the first
DMAH in the Al deposition process and the second Al deposition process
Al deposition was performed using MMAH ₂ instead of Al.

The deposition conditions and the surface modification step are as follows.

[0178] During the 1Al film forming step, when the total pressure 1.5 Torr DMAH partial pressure of 5 × 10 ^-4 Torr surface modification step, when TiCl ₄ partial pressure 0.1Torr first 2Al film forming step, total pressure 1.5 Torr DMAH partial pressure 5 × 10 ^-4 Torr.

In the above sample, in a temperature range of 160 ° C. to 400 ° C., Al was deposited only on exposed portions of Si in the first Al deposition step.
It was selectively deposited with the same thickness as O _2, and in the second Al deposition step, Al was deposited at the same deposition rate on both the SiO ₂ surface and the Al film deposited in the first deposition step.

In the surface modification step, instead of TiCl ₄ , Si
₂ H ₆ , or SiCl ₄ or SiHCl ₃ or SiH ₂ Cl ₂
Was supplied at a partial pressure of 0.1 to 50 Torr, and the same result was obtained.

Example 9 Al deposition was performed using the apparatus shown in FIG. The apparatus shown in FIG. 4 is obtained by adding a plasma generating electrode 16 and a plasma generating power supply 14 to the apparatus shown in FIG. When high-frequency power is applied to the plasma generating electrode 16 from the power supply 14, a plasma 15 is generated in the reaction tube 2.

In the same procedure as in Example 1, only in the surface modification step, the surface was modified under the conditions of a total H ₂ pressure of 1.0 Torr and a plasma power of 0.3 W / cm ^3, and Al deposition was performed. The substrate used was a Si substrate formed by patterning a SiO ₂ thin film manufactured by the same procedure as that shown in Example 1.

In the temperature range of 160 ° C. to 450 ° C., the first
In the Al deposition step, Al is selectively deposited only on the exposed portion of Si with the same thickness as SiO _2, and in the second Al deposition step, both the Al film deposited on the SiO ₂ surface and the Al film deposited in the first deposition step At the same deposition rate.

The Al film selected on Si and Si after the surface modification step
The Al film deposited on O ₂ did not differ in film quality such as resistivity, reflectance, and hillock generation density after the heat treatment step.

In addition, no increase in resistance occurred at the interface between the first Al film and the second Al film.

Even if the H ₂ pressure in the surface modification step was changed to 0.1 to ₂ Torr and the plasma power was changed to 0.2 to 1 W / cm ³ , there was no difference in the deposition rate and the Al film quality.

Example 10 Al deposition was performed using the apparatus shown in FIG. In the apparatus shown in FIG.
, And the lamp 22 can be heated to a higher temperature. Xe lamp is used as the lamp. 21 is a light transmission window, which is made of quartz.

In FIG. 5, the transfer chamber is mounted in a direction perpendicular to the paper surface (not shown). The deposition procedure is as follows.

The substrate was placed on the wafer holder 3 and H ₂ gas was added for 1.
It is introduced into the reaction vessel 2 at a pressure of 5 Torr, and then the heater 4 is energized and heated. After reaching a predetermined temperature, DMAH is introduced into the reaction vessel 2 to form a first Al film.

After a predetermined deposition time, the supply of only DMAH is stopped. The lamp 22 heats the wafer rapidly. After the substrate surface temperature reaches 500 ° C., DMAH is again introduced into the reaction vessel for 0.1 to 5 minutes. The supply of DMAH is stopped again, the lamp 22 is turned off, and the substrate temperature is lowered to a predetermined temperature.

The above is the surface modification step, and thereafter,
DMAH is introduced to deposit a second Al film. After the end of the predetermined deposition time, the supply of DMAH is stopped, the power supply to the heater is stopped, and cooling is performed.

At the time of the first Al film formation step, the total pressure is 1.5 Torr, the DMAH partial pressure is 1.5 × 10 ⁻⁴ Torr. At the time of the surface modification step, the substrate temperature is 500 ° C., the total pressure is 1.5 Torr, the DMAH partial pressure is 1.5 × 10 ⁻⁵ Torr. During the process, an Al film was deposited under the conditions of a total pressure of 1.5 Torr and a partial pressure of DMAH of 1.5 × 10 ⁻⁴ Torr.

The substrate used was the Si wafer used in Example 1 on which the SiO ₂ thin film was patterned.

In a temperature range of 160-450 ° C., in the first Al film deposition step, Al is not deposited on SiO ₂ , but Al having the same film pressure as that of SiO ₂ is deposited only on portions where Si is exposed. In the 2Al film deposition step, Al was deposited on the first Al film and SiO ₂ at substantially the same deposition rate.

The first Al film and the second Al film were analyzed by SIMS analysis and the like.
Although the presence of C was confirmed only at the interface, the presence of C did not increase the resistance at the interface between the first Al film and the second Al film. Further, the film quality of the deposited Al film was almost the same as in FIG.

(Embodiment 11) In the same procedure as in Embodiment 1, DM
At the same time as transferring AH to the reaction tube from the third gas line
Al-Si deposition was performed by adding Si ₂ H ₆ .

A first Al-Si film deposition step, a surface modification step,
Each condition of the second Al-Si film deposition step is as follows.

At the time of the first Al-Si film forming step, the total pressure is 1.5 Torr, the DMAH partial pressure is 1.5 × 10 ⁻⁴ Torr, the Si ₂ H ₆ partial pressure is 2 × 10 ⁻⁶ Torr, and the TiCl ₄ partial pressure is 0.1 Torr. During the 2Al-Si film forming step, the total pressure is 1.5 Torr, the DMAH partial pressure is 1.5 × 10 ^-4 Torr, and the Si ₂ H ₆ partial pressure is 2 × 10 ^-6 Torr.

In the temperature range of 160 ° C. to 450 ° C., the first
In the Al deposition step, Al-Si is selectively deposited only on the exposed portions of Si with the same thickness as SiO _2, and in the second Al-Si deposition step,
Al-Si was deposited at O ₂ surface and the same deposition rate both on the first Al-Si film deposited in the deposition step.

The Al-Si film selected on Si and the Al-Si film deposited on SiO ₂ after the surface modification step did not differ in film quality such as resistivity, reflectance, and hillock generation density after the heat treatment step. .

Further, no increase in resistance occurred at the interface between the first Al-Si film and the second Al-Si film.

The partial pressure of TiCl _{4 in the} surface modification step was set to 0.05 to 0.5.
Even when the pressure was changed to Torr, there was no difference in the deposition rate and the film quality of the Al-Si film.

Example 12 In the same procedure as in Example 11, instead of TiCl ₄ , Si ₂ H ₆ or SiCl ₄ or SiHCl ₃ or SiH ₂ Cl ₂ was introduced at a total pressure of 0.1 to 50 Torr in the surface modification step. An Al-Si film was deposited.

A first Al-Si film deposition step, a surface modification step,
Each condition of the second Al-Si film deposition step is as follows.

At the time of the first Al-Si film formation step, the total pressure is 1.5 Torr, the DMAH partial pressure is 1.5 × 10 ⁻⁴ Torr, the partial pressure of Si ₂ H _{6 is} 2 × 10 ⁻⁶ Torr, and the surface modification step is Si ₂ H ₆ or SiCl _4. Or SiHCl ₃ or SiH ₂ Cl ₂
During the second Al-Si film forming step, the total pressure is 1.5 Torr, the DMAH partial pressure is 1.5 × 10 ⁻⁴ Torr, and the Si ₂ H ₆ partial pressure is 2 × 10 ⁻⁶ Torr.

In the case where Si ₂ H ₆ is used in the surface modification step, the first
In the Al-Si deposition step, an Al-Si film having the same thickness as that of SiO ₂ is selectively deposited only on the exposed portion of the Si, the substrate temperature during the surface modification step is 200 ° C. to 450 ° C., and the Si ₂ H ₆ 0.1 to 50 Torr partial pressure and Al
When the partial pressure was higher than the partial pressure at the time of depositing Si, Al-Si was deposited at the same deposition rate on both the SiO ₂ and the first Al-Si film in the second Al-Si deposition step.

The film quality of the deposited Al—Si film was as good as in Example 1.

In the case of SiCl ₄ , SiHCl ₃ , and SiH ₂ Cl ₂ , in the first Al—Si deposition step, an Al—Si film having the same thickness as SiO ₂ is selectively deposited only on the exposed Si portion. When the substrate temperature during the surface modification step is 200 ° C. to 450 ° C. and the partial pressure of SiCl ₄ or SiHCl ₃ or SiH ₂ Cl ₂ is 0.1 to 50 Torr, the second Al—
In the Si deposition step, Al-Si was deposited on both the SiO ₂ and the first Al-Si film at the same deposition rate.

The film quality of the deposited Al—Si film was as good as in Example 1.

(Example 13) An Al-Si film was deposited by changing the partial pressure of Si ₂ H ₆ during the deposition of the Al-Si film in the same procedure as in Examples 11 and 12.

The first Al—Si film deposition step, the surface modification step,
Each condition of the second Al-Si film deposition step is as follows.

At the time of the first Al-Si film forming step, total pressure 1.5 Torr DMAH partial pressure 1.5 × 10 ⁻⁴ Torr Si ₂ H ₆ partial pressure 1.5 × 10 ⁻⁷ -1 × 10 ⁻⁴ Torr Base temperature 300 ° C. Surface modification During the process, Si ₂ H ₆ or SiCl ₄ or SiHCl ₃ or SiH ₂ Cl ₂
Partial pressure of 0.1 to 50 Torr or TiCl ₄ partial pressure of 0.05 to 0.5 Torr Base temperature 300 ° C. During the second Al-Si film forming step, total pressure 1.5 Torr DMAH partial pressure 1.5 × 10 ^-4 Torr Si ₂ H ₆ partial pressure 0.05 to 0.5 Torr The substrate temperature is 300 ° C. It should be noted that the first Al-Si deposition and the second Al-Si
Si ₂ H ₆ during deposition was made equal.

In the case where TiCl ₄ or Si ₂ H ₆ or SiCl ₄ or SiHCl ₃ or SiH ₂ Cl ₂ was used in the surface modification step, the SiO ₂ was deposited only on the exposed Si portion in the first Al-Si deposition step. An Al-Si film having the same thickness as that of
In the Al-Si deposition step, Al-Si was deposited at the same deposition rate on both the SiO ₂ and the first Al-Si film.

At this time, the Si content (Wt%) in the formed Al-Si film changed from 0.005% to 5% almost in proportion to the partial pressure of Si ₂ H ₆ transported simultaneously with DMAH.

(Example 14) In Examples 11 and 12, the carrier gas for transporting DMAH was changed from H ₂ to Ar during the first Al-Si deposition step and the second Al-Si deposition step. Al-Si was deposited in exactly the same procedure.

At the time of the first Al-Si deposition and at the time of the second Al-Si
At the time of Si deposition, H ₂ was supplied from the second gas line.

In this example, an Al—Si deposited film similar to that of Examples 11 and 12 was obtained.

(Embodiment 15) In Embodiment 13, the first A
l-Si deposition step, when the second Al-Si deposition step, a carrier gas for transporting the DMAH is changed from H ₂ to Ar, was deposited Al-Si in exactly the same procedure.

During the deposition of the first Al—Si and the second Al—
At the time of Si deposition, H ₂ was supplied from the second gas line.

In this example, an Al—Si deposited film similar to that of Example 13 was formed.

(Example 16) In the same procedure as in Examples 5, 6, and 7, in the first Al-Si film deposition step and the second Al-Si deposition step, Si ₂ H ₆ was removed. In addition, Al-Si deposition was performed.

The deposition conditions are as follows.

During the first Al film forming step, the reaction tube pressure was 0.3 Torr, the DMAH partial pressure was 3 × 10 ⁻⁵ Torr, the substrate temperature was 300 ° C., the Si ₂ H ₆ partial pressure was 1 × 10 ⁻⁶ Torr, and the TiCl ₄ partial pressure was during the surface modification step. 0.05 to 5 Torr, or Si ₂ H ₆ partial pressure 0.1 to 50 Torr, or SiCl ₄ partial pressure 0.1 to 50 Torr, or SiHCl ₃ partial pressure 0.1 to 50 Torr, or SiH ₂ Cl ₂ partial pressure 0.1 to 50 Torr At the time of the second Al film forming step, Reaction tube pressure 0.3 Torr DMAH partial pressure 3 × 10 ⁻⁵ Torr Si ₂ H ₆ partial pressure 1 × 10 ⁻⁶ Torr Substrate temperature: 300 ° C. Al was deposited.

Under the above conditions, in the first Al-Si film deposition step, no Al-Si is deposited on the non-electron donating surface, and only the exposed portion of the electron donating surface has the same thickness as the non-electron donating film. Al-Si is deposited and the second Al-Si after the surface modification step
In the film deposition step, Al-Si was deposited on the first Al-Si film and on the non-electron donating surface at almost the same deposition rate.

The film quality of the deposited Al-Si film was the same as that of the substrate temperature of 300 ° C. shown in Example 1, and was very good.

(Embodiment 17) The first procedure is the same as that of the first embodiment.
With MMAH ₂ in place of DMAH in Al-Si deposition step and the second Al-Si deposition step of, simultaneously with further MMAH ₂
Si ₂ H ₆ was supplied to the reaction tube to perform Al-Si deposition.

The deposition conditions and the surface modification step are as follows.

In the first Al-Si film forming step, the total pressure is 1.5 Torr, the DMAH partial pressure is 1 × 10 ⁻⁴ Torr, the Si ₂ H ₆ partial pressure is 1 × 10 ⁻⁵ Torr, and the TiCl ₄ partial pressure is 0.1 Torr. During the 2Al-Si film forming step, the total pressure is 1.5 Torr, the DMAH partial pressure is 5 × 10 ⁻⁴ Torr, and the Si ₂ H ₆ partial pressure is 1 × 10 ⁻⁵ Torr.

In the above sample, in the temperature range of 160 ° C. to 400 ° C., in the first Al—Si deposition step, Al—Si was selectively deposited only on the exposed Si portion with the same thickness as SiO ₂ , Al-
In the Si deposition step, Al-Si was deposited at the same deposition rate on both the SiO ₂ surface and the Al-Si film deposited in the first deposition step.

In the surface modification step, instead of TiCl ₄ , Si ₂ H ₆ ,
Or 0.1% of SiCl ₄ or SiHCl ₃ or SiH ₂ Cl ₂
The same result was obtained even when supplied at a partial pressure of ~ 50 Torr.

Example 18 Al-Si deposition was performed using SiH ₄ in place of Si ₂ H ₆ added when transporting DMAH in the same procedure as in Examples 11 and 12.

Deposition was performed with a partial pressure of SiH ₄ of 1 × 10 ⁻⁵ Torr against a partial pressure of DMAH of 1.5 × 10 ⁻⁴ Torr.

The deposition of Al—Si was performed according to Example 11 and Example 11.
Same as 12.

(Embodiment 19) In the same procedure as in Embodiment 9, DMAH
Was performed Al-Si deposited by simultaneously transporting Si ₂ H ₆ when the transport.

First Al-Si Deposition Step and Second Al
−Reactor pressure 1.5 Torr, DMAH partial pressure 1.5 × 10 in Si deposition process
^The deposition was performed at ^-5 Torr and a partial pressure of Si ₂ H _{6 of} 2 × 10 ^-6 Torr.

In the temperature range of 160 ° C. to 450 ° C., the first
In the Al-Si deposition step, Al-Si is selectively deposited only on the exposed portion of Si with the same thickness as SiO _2, and in the second Al-Si deposition step,
Al-Si was deposited at the same deposition rate on both the SiO ₂ surface and the Al-Si film deposited in the first deposition step.

The Al-Si film selected on Si and the Al-Si film deposited on SiO ₂ after the surface modification step did not differ in film quality such as resistivity, reflectance, and hillock generation density after the heat treatment step. .

In addition, no increase in resistance occurred at the interface between the first Al-Si film and the second Al-Si film.

Even if the H ₂ pressure in the surface modification step was changed to 0.1 to ₂ Torr and the plasma power was changed to 0.2 to 1 W / cm ³ , there was no difference in the deposition rate and the Al-Si film quality.

(Example 20) In the same procedure as in Example 10, in the first Al-Si deposition step and the second Al-Si deposition step, Si ₂ H ₆ was transported together with DMAH to deposit Al-Si. Was done.

The deposition conditions are as follows.

In the first Al film forming step, the total pressure is 1.5 Torr DMAH partial pressure 1.5 × 10 ^-4 Torr Si ₂ H ₆ partial pressure 1.0 × 10 ^-6 Torr In the surface modification step, the substrate temperature is 500 ° C. and the total pressure is 1.5 Torr DMAH Partial pressure 1.5 × 10 ^-5 Torr During the second Al-Si film formation step, Al-Si is deposited under the condition of total pressure 1.5 Torr DMAH partial pressure 1.5 × 10 ^-4 Torr Si ₂ H ₆ partial pressure 1 × 10 ^-6 Torr did.

The substrate used was the Si wafer patterned in the SiO ₂ thin film used in Example 1. In the temperature range of 160-450 ° C., in the first 1Al-Si film deposition step, on the SiO ₂ A
1-Si is not deposited, Al-Si having the same thickness as SiO ₂ is deposited only on the portion where Si is exposed, and in the _second Al-Si film deposition step, almost the same on the first Al-Si film and SiO ₂ Al-Si was deposited at the deposition rate.

The first Al film and the second Al film were analyzed by SIMS analysis and the like.
The presence of C was confirmed only at the film interface, but there was no increase in resistance at the interface between the first Al-Si film and the second Al-Si film due to the presence of C. The film quality of the deposited Al-Si film was almost the same as that of FIG.

Example 21 Al was deposited on a SiO ₂ patterned Si substrate in the same manner as in Example 1 by using the CVD apparatus shown in FIG. The deposition procedure was the same as in Example 1
Place the substrate in wafer holder, heating the substrate at the desired H ₂ pressure. Next, after reaching a desired substrate temperature, DMAH is supplied, and Al is selectively deposited only on the exposed Si surface, which is an electron-donating surface. The Al deposited in this process is replaced with the first Al
And After a lapse of a predetermined time, plasma is generated while keeping the total pressure and the DMAH partial pressure constant. After a lapse of a predetermined time, the plasma is stopped, and Al is further deposited. At this time, on the selectively deposited Al and on the non-electron donating surface
Al is non-selectively deposited on SiO ₂ . The Al film deposited non-selectively is referred to as second Al. After a predetermined time, DM
Stop the supply of AH and end the deposition. The deposition time of the first Al film is a time until the thickness of the selectively deposited Al film becomes equal to the thickness of SiO ₂ .

In the present embodiment, the first gas line
Supply. Carrier gas DMAH line with H _2.
The second gas line is used for H _2.

The conditions of the first Al film deposition step, the surface modification step, and the second Al film deposition step are as follows.

First Al film deposition step; Total pressure: 0.1, 1.2, 5 Torr DMAH partial pressure: 1 × 10 ^-3 times the total pressure Surface modification step; Total pressure, DMAH partial pressure: First Al film deposition Same as process Plasma power density (W / cm ^-3 ): 0.01, 0.015, 0.02, 0.0
3, 0.04, 0.06, 0.07, 0.08, 0.10, 0.20, 0.40 Plasma application time: 1 minute Second Al film deposition process; Total pressure, DMAH partial pressure: Same as the first Al film deposition process Total pressure (3 types ) And the plasma applied power (11 types) in the surface modification step, the substrate temperature was set to 13 levels from 150 ° C. to 470 ° C., and the Al film was deposited. The selectively deposited first Al film was a single crystal. The film quality of the deposited Al film was the same as in FIG. Table 4 shows the measurement results of carbon at the interface between the first Al film and the second Al film. At a substrate temperature of 150 ° C., no film was deposited on the substrate. Further, when the plasma application power density during the surface modification step is 0.01 and 0.015 W / cm ^-3, on the SiO ₂ surface irrespective of the substrate temperature A
No film was deposited. When the applied power density of the plasma in the surface modification step was 0.08 W / cm ^-3 or more, carbon was detected at the interface between the first Al film and the second Al film. The contact resistance at the interface between the first Al film and the second Al film is a plasma power density of 0.02.
It increased from the case of 0.00.07 W / cm ⁻³ .

[0249]

[Table 4]

(Example 22) Al was produced in the same procedure as in Example 21.
Deposition was performed. The deposition conditions other than the plasma application time during the surface modification are the same as in Example 21. Plasma application time
Al deposition was performed for 10 seconds, 30 seconds, 3 minutes, 5 minutes, and 10 minutes.

When the plasma application time was 10 seconds, 30 seconds, and 3 minutes, the film quality obtained was the same as in FIG. When the plasma application time was 5 minutes or 10 minutes, the film quality other than the surface reflectance was the same as in FIG. 7 and Table 4, but the surface reflectance was worse than the value shown in FIG. At 350 ° C., it was approximately 65-75%.

(Embodiment 23) Al was produced in the same procedure as in Embodiment 21.
Deposition was performed. A first Al film deposition step, a surface modification step,
The deposition conditions other than the DMAH partial pressure in the second Al film deposition step are the same as those in Example 21. 1 × 10 ^-5 of all pressure DMAH partial pressure, 5
× 10 ^-5 , 1 × 10 ^-5 and 5 × 10 ^-4 times.

The quality of the obtained film was the same as in FIG. 7 and Table 4. The obtained film quality did not depend on the DMAH partial pressure.

(Example 24) Al was produced in the same procedure as in Example 21.
Deposition was performed. The difference from Example 21 is that the apparatus of FIG.
The point is that Ar was used as the carrier gas for the AH line. The deposition conditions other than the carrier gas are the same as in Example 21.

The film quality of the obtained Al film was the same as in FIG. Plasma power density during surface modification step is 0.01 to 0.01
At 5 W / cm ^-3, no Al film was formed on SiO ₂ . When the plasma power density is 0.02 W / cm ^-3 or more, the second A
1 film was deposited on SiO 2, but the first Al film and the second Al film
According to SIMS analysis, carbon was detected at the film interface.

(Example 25) Al was produced in the same manner as in Example 24.
Deposition was performed. The deposition conditions other than the plasma application time during surface modification are the same as in Example 24. Plasma application time
Al deposition was performed for 10 seconds, 30 seconds, 3 minutes, 5 minutes, and 10 minutes.

When the plasma application time was 10 seconds, 30 seconds, and 3 minutes, the film quality obtained was the same as in FIG. When the plasma application time was 5 minutes or 10 minutes, the film quality other than the surface reflectance was the same as in FIG. 7 and Table 4, but the surface reflectance was worse than the value shown in FIG. Nearly 65 at 350 ° C
~ 75%. When the plasma power density was 0.02 W / cm ^-3 or more irrespective of the plasma application time, the second Al film was also deposited on SiO ₂ , but the interface between the first Al film and the second Al film was According to SIMS analysis, carbon was detected.

(Example 26) Al was produced in the same procedure as in Example 24.
Deposition was performed. A first Al film deposition step, a surface modification step,
The deposition conditions other than the DMAH partial pressure in the second Al film deposition step are the same as in Example 24. 1 × 10 ^-5 of all pressure DMAH partial pressure, 5
× 10 ⁻⁵ , 1 × 10 ⁻⁴ , 5 × 10 ⁻⁴ times.

The quality of the obtained Al film was the same as that of FIG. Plasma power density during surface modification process is 0.01, 0.01
In the case of 5 W / cm ^-3, no Al film was formed on SiO ₂ . When the plasma power density is 0.02 W / cm ^-3 or more, the second A
1 film was also deposited on SiO ₂ , but the first Al film and the second
According to SIMS analysis, carbon was detected at the interface of the 1 film.

(Example 27) Examples 21, 22, 23, 24, 25,
Various substrates shown in Example 5 (samples 5-1 to 5-179 shown in Tables 1, 2 and 3) under the same procedures and conditions as in 26.
An Al film was deposited.

In the first Al film deposition step, Al is selectively deposited only on the electron donating surface, and Al is deposited on the non-electron donating surface.
No film was deposited. In the second Al film deposition step after the surface modification step, the Al film was deposited on the first Al film and the non-electron donating surface at substantially the same deposition rate. The film quality of the deposited Al film was as good as in Examples 21, 22, 23, 24, 25 and 26.

Example 28 Al was deposited on a SiO ₂ patterned Si substrate in the same manner as in Example 1 by using the CVD apparatus shown in FIG. DM in the same deposition procedure as in Example 21
AH was transported to the reaction tube, and Si ₂ H ₆ was added from the third gas line to deposit Al—Si.

In this embodiment, the DMAH
Supply. Carrier gas DMAH line with H _2.
The second gas line is used for H _2. The third gas line
For Si ₂ H ₆

The conditions for the first Al-Si film deposition step, the surface modification step, and the second Al-Si film deposition step are as follows.

First Al—Si film deposition step; total pressure: 0.1, 1.2, 5 Torr DMAH partial pressure: 1 × 10 ⁻³ times the total pressure Si ₂ H ₆ partial pressure: 0.01 times the DMAH partial pressure Surface modification Process: Total pressure, DMAH partial pressure, Si ₂ H ₆ partial pressure: same as the first Al-Si film deposition process Plasma power density (W / cm ^-3 ): 0.01, 0.015, 0.02, 0.0
3, 0.04, 0.06, 0.07, 0.08, 0.10, 0.2, 0.4 Plasma application time: 1 minute Second Al-Si film deposition process; total pressure, DMAH partial pressure, Si ₂ H ₆ partial pressure: first Al- For the same combination of total pressure (3 types) and plasma applied power (11 types) in the surface modification process as in the Si film deposition process,
Al-Si film deposition was performed at 13 levels from 150 ° C to 470 ° C. The film quality of the deposited Al-Si film was the same as in FIG. 7, and the measurement results of carbon at the interface between the first Al film and the second Al-Si film were the same as in Table 4. At a substrate temperature of 150 ° C., no film was deposited on the substrate. Further, when the plasma applied power density during the surface modification step was 0.01 and 0.015 W / cm ^-3 , SiO ₂
No Al-Si film was deposited on the surface. When the plasma applied power density during the surface modification step is 0.08 W / cm ^-3 or more, the first
Carbon was detected at the interface between the Al-Si film and the second Al-Si film. The contact resistance at the interface between the first Al—Si film and the second Al—Si film was increased as compared with the case where the plasma power density was 0.02 to 0.07 W / cm ⁻³ .

(Example 29) In the same procedure as in Example 28, the partial pressure of Si ₂ H ₆ in the first Al-Si film deposition step and the second Al-Si film deposition step was changed to change the Al-Si Deposition was performed. The conditions of the first Al-Si film deposition step, the surface modification step, and the second Al-Si film deposition step are as follows.

First Al—Si film deposition step; Total pressure: 0.1, 1.2, 5 Torr DMAH partial pressure: 1 × 10 ⁻³ times the total pressure Si ₂ H ₆ partial pressure: 1 × 10 ^{−3 of the} DMAH partial pressure １1 times surface modification process; total pressure, DMAH partial pressure, Si ₂ H ₆ partial pressure: same as the first Al-Si film deposition process Plasma power density (W / cm ^-3 ): 0.01, 0.015, 0.02, 0.0
3, 0.04, 0.06, 0.07, 0.08, 0.10, 0.2, 0.4 Plasma application time: 1 minute Second Al-Si film deposition process; total pressure, DMAH partial pressure, Si ₂ H ₆ partial pressure: first Al- For the same combination of total pressure (3 types) and plasma applied power (11 types) in the surface modification process as in the Si film deposition process,
Al-Si films were deposited at 13 levels from 150 ° C. to 470 ° C. while changing the partial pressure of Si ₂ H ₆ . In the first Al-Si film deposition step, Al-Si is selectively deposited only on exposed portions of the Si surface,
In the second Al-Si film deposition step, the first Al-Si film and
An Al-Si film was deposited on SiO ₂ at almost the same deposition rate.
The Si content in the deposited Al-Si film varied from 0.005% to 5% almost in proportion to the added Si ₂ H ₆ partial pressure. The film quality of the deposited Al—Si film was as good as in Example 21.

(Example 30) In the same procedure as in Example 28,
-Si deposition was performed.

The deposition conditions other than the plasma application time during the surface modification are the same as in Example 28. Plasma application time is 10
Al-Si deposition was performed for seconds, 30 seconds, 3 minutes, 5 minutes, and 10 minutes.

When the plasma application time was 10 seconds, 30 seconds, and 3 minutes, the obtained film quality was the same as in FIG. 7 and Table 4. When the plasma application time was 5 minutes or 10 minutes, the film quality other than the surface reflectance was the same as in FIG. 7 and Table 4, but the surface reflectance was worse than the value shown in FIG. At 350 ° C., it was approximately 65-75%.

(Example 31) In the same procedure as in Example 28,
-Si deposition was performed.

In the first Al-Si film deposition step, the surface modification step, and the second Al-Si film deposition step, the DMAH partial pressure and the Si ₂ H
The deposition conditions other than the ₆ partial pressure are the same as in Example 21. The DMAH partial pressure was set to 1 × 10 ⁻⁵ , 1 × 10 ⁻⁴ , and 5 × 10 ⁻⁴ times the total pressure.
The Si ₂ H ₆ partial pressure is 0.01 times the DMAH partial pressure.

The film quality of the deposited Al—Si film was as good as in Example 21.

(Example 32) Al was produced in the same procedure as in Example 28.
-Si deposition was performed. The difference from Example 28 was that the apparatus of FIG. 6 used Ar as the carrier gas for the DMAH line. The deposition conditions other than the carrier gas are the same as in Example 28.

The film quality of the obtained Al—Si film was as good as in FIG. The plasma power density during the surface modification process is 0.
In the case of 01 and 0.015 W / cm ^-3, no Al-Si film was formed on SiO ₂ . When the plasma power density was 0.02 W / cm ^-3 or more, the second Al-Si film was deposited on SiO ₂ , but the interface between the first Al-Si film and the second Al-Si film was SIMS. Analysis detected carbon.

(Example 33) Al was produced in the same manner as in Example 29.
-Si deposition was performed. The deposition conditions other than the plasma application time during surface modification are the same as in Example 24. Al-Si deposition was performed with plasma application times of 10 seconds, 30 seconds, 3 minutes, 5 minutes, and 10 minutes.

When the plasma application time was 10 seconds, 30 seconds, and 3 minutes, the film quality obtained was the same as in FIG. When the plasma application time was 5 minutes or 10 minutes, the film quality other than the surface reflectance was the same as in FIG. 7 and Table 4, but the surface reflectance was worse than the value shown in FIG. Almost 65 at 350 ° C
~ 75%. When the plasma power density is 0.02 W / cm ^-3 or more regardless of the plasma application time, the second Al-Si film
Although deposited on O ₂ , the first Al—Si film and the second Al—S
Carbon was detected at the i-film interface by SIMS analysis.

(Example 34) Al was produced in the same procedure as in Example 28.
Deposition was performed. The deposition conditions other than the partial pressure of DMAH in the first Al-Si film deposition step, the surface modification step, and the second Al-Si film deposition step are the same as those in Example 28. DMAH partial pressure is 1 × of total pressure
10 ^-5 , 5 × 10 ^-5 , 1 × 10 ^-4 and 5 × 10 ^-4 times. Si ₂ H ₆
The partial pressure is 1 × 10 ⁻³ times the DMAH partial pressure.

The quality of the obtained Al film was the same as that of FIG. Plasma power density during surface modification process is 0.01, 0.01
At 5 W / cm ^-3, no Al-Si film was formed on SiO ₂ . When the plasma power density was 0.02 W / cm ^-3 or more, the second Al-Si film was deposited on SiO ₂ , but the interface between the first Al-Si film and the second Al-Si film was SIMS. Analysis detected carbon.

(Example 35) Examples 28, 29, 30, 31, 32,
Various substrates shown in Example 5 (samples 5-1 to 5-17 shown in Tables 1, 2 and 3) under the same procedures and conditions as in 33 and 34.
9) An Al-Si film was deposited.

In the first Al—Si film deposition step, deposition was selectively performed only on the electron donating surface, and no Al—Si film was deposited on the non-electron donating surface. In the second Al-Si film deposition step after the surface modification step, the Al-Si film was deposited on the first Al-Si film and the non-electron donating surface at substantially the same deposition rate. The film quality of the deposited Al-Si film was as shown in Examples 28, 29, 30,
As good as 31, 32, 33 and 34.

Example 36 Al was deposited on a SiO ₂ patterned Si substrate by using the CVD apparatus shown in FIG.

The method of manufacturing a Si substrate on which SiO ₂ is patterned is the same as that in the first embodiment.

First, the procedure for depositing Al will be described.

After cleaning the Si wafer, the transfer chamber 10 is released to the atmospheric pressure, and the Si wafer is loaded into the transfer chamber. Transfer chamber is approximately 1 × 10
After evacuating to ⁻⁶ Torr, the gate valve 13 is opened and the wafer is mounted on the wafer holder 3. After mounting the wafer on the wafer holder 3, the gate valve 13 is closed and the reaction chamber 2 is evacuated until the degree of vacuum in the reaction chamber 2 becomes approximately 1 × 10 ⁻⁸ Torr. However,
Even if the degree of vacuum in the reaction chamber cannot be exhausted to 1 × 10 ^-8 Torr, A
l deposits.

In the present embodiment, the DMAH
Supply. Carrier gas DMAH line with H _2.
The second gas line is used for H _2.

H ₂ is supplied from the second gas line to adjust the opening of the slow leak valve 8 so that the pressure in the reaction tube 2 becomes a predetermined value. The pressure in this embodiment is 0.1 to 5 torr. Thereafter, the heater 4 is energized to heat the wafer. After the wafer reaches a predetermined temperature, the plasma generating electrodes 16,
High-frequency power is applied to 16 ', 16 "to generate plasma in the reaction tube 2. The plasma generation at this time is referred to as" first plasma ". The oscillation frequency of the power supply for plasma generation is
It is about 13.56 MHz.

After plasma generation, DMAH is introduced into the reaction tube from the DMAH line. The partial pressure of DMAH is approximately 1 × 10 ^-5 of the total pressure
To 2 × 10 ^-3 times. When DMAH is introduced, Al is deposited. The Al film deposited in this process is referred to as a first Al film.

After a predetermined time has elapsed, the plasma generation power is increased while keeping the substrate temperature, the total pressure, and the DMAH partial pressure constant. The plasma generation at this time is referred to as “second plasma”. After a certain period of time (where the second plasma generation is the surface modification step and the certain period of time is the second plasma generation time), the total pressure, the DMAH partial pressure, and the substrate temperature were kept constant. As it is, the plasma power is reduced again. The reduced plasma generation state is referred to as a third plasma. The Al film deposited during the generation of the third plasma is referred to as a second Al.

After the elapse of a predetermined time, the heating of the heater 4 is stopped, and the wafer is cooled. The supply of the H ₂ gas is stopped, the inside of the reaction vessel 2 is evacuated, and the wafer is transferred to the transfer chamber. Only the transfer chamber is opened to the atmosphere and the wafer is taken out.

The substrate temperature was 150 ° C., 160 ° C., 200 ° C., 250 ° C., 270 ° C.
℃, 300 ℃, 350 ℃, 370 ℃, 400 ℃, 430 ℃, 450 ℃, 470 ℃ 13
The Al film was deposited according to the procedure described above.

At the time of the first Al deposition step, total pressure: 0.1 torr, 1.2 torr, 5 torr DMAH partial pressure: 1 × 10 ⁻³ times the total pressure First plasma generation power (W / cm ⁻³ ): 0.01, 0.015, 0.03,
0.04, 0.06, 0.07, 0.08, 0.10, 0.20, 0.40 Total pressure and DMAH partial pressure during the surface modification step: same as the first Al film deposition step Second plasma generation power (W / cm ^-3 ): 0.01 , 0.015, 0.03,
0.04, 0.06, 0.07, 0.08, 0.10, 0.20, 0.40 Second plasma generation time: 1 minute During the third Al film deposition step, total pressure and DMAH partial pressure: same as the first Al deposition step Third plasma Generated power (W / cm ^-3 ): same as in the first Al deposition step. The results of Al deposition were as follows.

In the first Al film deposition step, the state of Al deposition was different depending on the first plasma generation power. That is, the first plasma generation power density is 0.01 and 0.0
At 15 Wcm ^-3 , Al is selectively deposited only on Si as shown in FIG. 8A, and the second Al film deposited through the surface modification step is as shown in FIG. 8C. Was flat. On the other hand, when the power density is increased, Al is deposited not only on Si but also on SiO ₂ as shown in FIG.
The l film had poor flatness as shown in FIG. 8 (d). FIG. 9 shows the form of deposition, carbon content, and reflectance of the Al film when the first plasma generation power density was changed in the first Al film deposition step. Also, the first Al
Table 5 shows the deposition form and the carbon-containing reflectance of the Al film deposited in the film deposition step, the surface modification step, and the second Al film deposition step. In each case, the reflectance was inferior to that of Example 21. Similar results were obtained when Al-Si was deposited by adding Si ₂ H ₆ .

[0294]

[Table 5]

(Example 37) An Si substrate on which SiO ₂ was patterned was produced in the same procedure as in Example 1. Next, the first Al was selectively deposited only on Si in the same manner as in Example 1 using the apparatus shown in FIG. This Si substrate was set in a sputtering apparatus, and RF sputter etching was performed in an Ar atmosphere of 10 ^-2 Torr. The substrate holder was kept at 200 ° C., and high-frequency power of 100 W was applied to the high-frequency electrode to perform etching for 60 seconds. As a result, SiO ₂ surfaces with oxides having a thickness of about 100 Å of the first Al surface is also removed by the same thickness, simultaneously SiO ₂
The surface has been modified. Next, an Al film was deposited by DC sputtering using Al as a target. 10 ^-2 Torr
A second Al film was uniformly deposited on Si and SiO ₂ at a deposition rate of 1000Å / min under the conditions of an Ar atmosphere, a substrate holder temperature of 250 ° C., and a DC power of 7 kW. First Al film and second Al film
There was no high resistance layer at the interface with the film.

The selective deposition of the first Al film may be performed by any of the methods described in the above embodiments, and the non-selective deposition of the second Al film by sputter etching and sputter deposition is not limited to the above conditions. Instead, it can be performed under ordinary sputtering conditions.

[0297] A first Al-Si alloy film is selectively deposited on Si, the surface oxide and the SiO ₂ surface of the first Al-Si film are removed by sputter etching, and the Al-Si alloy is targeted. Needless to say, the second Al-Si alloy film can be uniformly deposited.

[0298]

As described above, according to the present invention,
A low-resistance, dense and flat Al or Al-Si film can be formed continuously in the opening formed in the insulating film on the substrate and on the insulating film, so that a wiring structure for a semiconductor integrated device having excellent characteristics can be formed at high speed. And can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a state of forming a wiring film by a wiring structure manufacturing method according to the present invention.

FIG. 2 is a schematic view showing an example of a deposited film forming apparatus to which the present invention can be applied.

FIG. 3 is a schematic view showing another example of a deposited film forming apparatus to which the present invention can be applied.

FIG. 4 is a schematic view showing another example of a deposited film forming apparatus to which the present invention can be applied.

FIG. 5 is a schematic view showing still another example of a deposited film forming apparatus to which the present invention can be applied.

FIG. 6 is a schematic view showing still another example of a deposited film forming apparatus to which the present invention can be applied.

FIG. 7 is a diagram showing evaluation results of an aluminum film formed by changing a substrate temperature.

FIG. 8 is a schematic diagram for explaining formation of a wiring film by a wiring structure manufacturing method according to the present invention.

FIG. 9 is a diagram showing a deposition form, a carbon content, and a reflectance of a film when the deposition is performed while changing the plasma generation power density in the first Al film deposition step.

FIG. 10 is a schematic diagram for explaining a state of film formation by a conventional deposited film formation method.

[Explanation of symbols]

 1 Substrate 2 Reaction tube 3 Substrate holder 4 Heater 5 Mixer 6 Vaporizer 7 Gate valve 8 Slow leak valve 9 Exhaust unit 10 Transfer chamber 11 Valve 12 Exhaust unit 13 Gate valve 14 Power supply for plasma generation 15 Plasma generation area 16, 16 ' , 16 ″ Metal electrode 21 Light transmission window 22 Wafer heating lamp 50 Quartz outer reaction tube 51 Quartz inner reaction tube 52 Source gas introduction line 53 Gas exhaust port 54 Metal flange 56 Substrate holder 57 Substrate 58 Gas flow 59 Heater section 90 Electron-donating substrate 91 Non-electron-donating thin film 92 Deposited film

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-248471 (JP, A) JP-A-62-123716 (JP, A) JP-A-3-35526 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) H01L 21/28-21/288 H01L 21/3205 H01L 21/3213 H01L 21/44-21/445 H01L 21/768 H01L 29/40-29/51

Claims (3)

(57) [Claims] A step of disposing a substrate having an insulating film provided with an opening in a CVD apparatus, maintaining the temperature of the substrate at a temperature not lower than the decomposition temperature of alkyl aluminum hydride and not higher than 450 ° C. Supplying aluminum hydride gas and hydrogen gas onto the substrate to form aluminum in the opening; and modifying the surface of the insulating film in which aluminum is formed in the opening, and Maintaining the temperature of the substrate in the range of not less than the decomposition temperature of alkyl aluminum hydride and 450 ° C. or less, supplying a gas of alkyl aluminum hydride and hydrogen gas onto the substrate,
A method for manufacturing a wiring structure for a semiconductor integrated circuit device, comprising a step of forming an aluminum film on the surface-modified insulating film and on aluminum in the opening. 2. The method according to claim 1, wherein the aluminum film contains silicon. 3. An insulating film is provided on a substrate, an opening provided in the insulating film is filled with a conductor, the opening is flattened, and the opening of the substrate below the opening is formed. In a method of manufacturing a wiring structure for a semiconductor integrated circuit device having a wiring structure in which a surface and a conductive film provided on the insulating film are electrically connected, a substrate having the insulating film provided with the opening is provided. Disposing in a CVD apparatus, maintaining the temperature of the substrate in a range of not less than the decomposition temperature of alkyl aluminum hydride and not more than 450 ° C., supplying a gas of alkyl aluminum hydride and hydrogen gas onto the substrate, Forming a hole in the opening, a step of modifying the surface of the insulating film in which single-crystal aluminum is formed in the opening, and a step on the surface-modified insulating film and in the opening. Simply Preparation of a semiconductor integrated circuit device wiring structure characterized by comprising a step of forming the conductive film on the crystal aluminum.