WO2011055671A1 - Film forming method and method for forming capacitor - Google Patents

Film forming method and method for forming capacitor Download PDF

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Publication number
WO2011055671A1
WO2011055671A1 PCT/JP2010/069125 JP2010069125W WO2011055671A1 WO 2011055671 A1 WO2011055671 A1 WO 2011055671A1 JP 2010069125 W JP2010069125 W JP 2010069125W WO 2011055671 A1 WO2011055671 A1 WO 2011055671A1
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film
gas
stress
forming
substrate
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PCT/JP2010/069125
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French (fr)
Japanese (ja)
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村上 誠志
麻由子 石川
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東京エレクトロン株式会社
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    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/22Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
    • C23C16/30Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
    • C23C16/34Nitrides
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/56After-treatment
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L28/00Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
    • H01L28/40Capacitors
    • H01L28/60Electrodes
    • H01L28/82Electrodes with an enlarged surface, e.g. formed by texturisation
    • H01L28/90Electrodes with an enlarged surface, e.g. formed by texturisation having vertical extensions

Abstract

Disclosed is a film forming method which comprises: a step wherein a starting material gas containing titanium and a nitrogen-containing gas are supplied onto a substrate to be processed in a process chamber and a titanium nitride film is formed on the substrate to be processed by a heat treatment; and a step wherein the titanium nitride film is subjected to a plasma treatment by which the stress of the film is reduced.

Description

Method of forming a film forming method and a capacitor

The present invention relates to a method of forming a film forming method and a capacitor forming a thin film on the surface of a semiconductor wafer.

In general, in order to form a semiconductor integrated circuit such as an IC is a semiconductor wafer and the surface of the glass substrate, the film forming process, an etching process, thermal diffusion treatment, desired transistor elements by repeating many times oxidation treatment , resistance element, has a capacitor or the like so that high density integrated form. Recently, in particular, with the high integration of a semiconductor device, in more proceeds tendency miniaturization of the element itself. For example, the area occupied by each cell In the memory device such as DRAM becomes smaller and smaller with miniaturization trend, in order to ensure a sufficient capacitance value of the insulating layer between the capacitor electrodes be occupied area is reduced the thickness or thinner, or it may be increased relative permittivity of the dielectric, the insulating and the thickness thinning of the insulating layer is deteriorated and also, various well to the material with high dielectric at present, there is a technical problem.

Therefore, a structure that can be occupied area or volume occupied is to increase the capacitance of the capacitor be less tubular capacitor, or the structure of molded capacitor cylindrical shape has been proposed (e.g. Patent Document 1) .

As the electrode used in the capacitor, conventionally, in general although polysilicon film is used, in the recent years, even miniaturized specific resistance is relatively low and such excellent step coverage becoming a titanium nitride film (TiN film) is used for reasons. For example, a cylinder-shaped capacitor in a DRAM memory cell includes a bottom electrode main surface is connected to the contact plug extending from one of the source and drain regions formed to sandwich the gate electrode was shaped cylinder silicon substrate (semiconductor wafer) , high dielectric constant and film, and an upper electrode formed on the surface of the high dielectric constant film, titanium nitride as these lower and upper electrodes of HfO 2 or the like formed on the surface of the cylindrical lower electrode (TiN) film is used. Cylindrical capacitor having such a structure is arrayed in a matrix on the main surface of the Si substrate.

The titanium nitride film, the need to perform sufficient film with even finer tubular body shaped in the lower electrode is deposited by thermal CVD (Chemical Vapor Deposition) method is a high step coverage deposition method. The deposition of TiN by thermal CVD method, for example, the NH 3 is used as a raw material gas as a nitriding gas with TiCl 4, a TiN film is formed on the substrate by supplying them onto a heated substrate. Further, a step of supplying a material gas and nitriding gas, the step of supplying only gas nitriding, has also been deposited by SFD (Sequential Flow Deposition) process to be carried out alternately across the purge.

JP 2002-222871 JP JP-T 2001-507514 JP JP 2004-263207 JP

Incidentally, in general, in the TiN film formation, but the specific resistance of as the film raising the deposition temperature decreases, stress opposite to the membrane when the specific resistance decreases increases. That is, stress resistivity and film membrane has a relationship contradictory, high quality film resistivity stress is increased. In particular, although specific resistance by low-temperature film-forming by SFD very low film is obtained, the stress of the film becomes particularly high.

When stress thus film is increased, or the focus deviates during photolithography entire wafer is warped, or cause cracks and breaks in the tubular or cylindrical capacitor, also due to such warpage wafer It occurs inconvenience that clamping or electrostatic adsorption itself may become insufficient. Further, also known is a structure to which is linked with supports cylindrical capacitor adjacent to the strength retention bar, the support bar is damaged by the stress of the TiN film, there is a problem that.

Such problems may be caused as well in forming by the thermal CVD another film such as tungsten (W) film.

Accordingly, an object of the present invention is to provide a film forming method capable of forming a film with less stress on the surface of the object.
Another object of the present invention is to provide a method of forming a capacitor using the above film forming method.

According to a first aspect of the present invention, and forming a titanium nitride film on a substrate to be processed by heat treatment by supplying the substrate to be processed in the processing chamber and a raw material gas and a nitrogen-containing gas containing titanium, film forming method and a performing a process of reducing the stress of the film by the plasma relative to the titanium nitride film is provided.

According to a second aspect of the present invention, a first step of forming a titanium nitride film on a substrate to be processed by heat treatment by supplying the substrate to be processed in the processing chamber and a raw material gas and a nitrogen-containing gas containing titanium If, at the same time as nitriding said titanium nitride layer by stopping the supply of the raw material gas by supplying the nitrogen-containing gas, alternating with second step of generating a plasma to reduce the stress of the membrane into the processing chamber to provide a film forming method of repeating.

According to a third aspect of the present invention, and forming a tungsten film on a substrate to be processed by heat treatment by supplying the substrate to be processed in the raw material gas and a reducing gas and a process vessel containing tungsten, the tungsten film forming method and a performing a process of reducing the stress of the film by the plasma relative to the membrane is provided.

According to a fourth aspect of the present invention, there is provided a method of forming a capacitor for forming a capacitor on the surface of the substrate, forming a plurality of recesses the surface of the insulating layer provided on the surface of the substrate nitride possible and, on the surface of the insulating layer including the surface of the plurality of the recesses, on a substrate to be processed by heat treatment by supplying the raw material gas and a nitrogen-containing gas containing titanium on a substrate to be processed in the processing chamber forming a first thin film made of a titanium nitride film by using a film forming method having the applying process of reducing the stress of that and the film by the plasma relative to the titanium nitride film to form a titanium film, said and removing said first thin film of the surface of the insulating layer so as to leave said first thin film on the surface of the plurality of the concave portion, wherein the first thin film tubular by removing the insulating layer this left as projections If, forming a high dielectric constant film on the entire surface including the surface of the remaining cylindrical projections on the surface of the high dielectric constant film, container processing and the raw material gas and a nitrogen-containing gas containing titanium forming a titanium nitride film on a substrate to be processed by the heat treatment is supplied to the substrate to be processed within a film formation method with applying the process of reducing the stress of the film by the plasma relative to the titanium nitride film and forming a second thin film made of a titanium nitride film with electrically the high dielectric constant film and the second thin film remaining between the plurality of cylindrical projections are removed by etching method of forming a capacitor having and forming a plurality of capacitors divided into is provided.

It is a schematic plan view illustrating the processing system as one example of an apparatus for carrying out the method of the present invention. Is a block diagram showing a first processing apparatus for forming a TiN film mounted to the processing system of Figure 1. Is a block diagram showing a second processing unit for performing processing to reduce the film stress by onboard plasma processing system of FIG. Is a flow chart showing the steps of the film forming method of the present invention performed in the processing system of FIG 1. Is a diagram showing an example of a timing chart when forming a film of TiN film by SFD method. It is an X-ray diffraction profile having a diffraction peak position of the TiN (200) of the TiN film remains deposited (as depo). It is a schematic view showing the state of the crystal lattice of the TiN film as-deposited (as depo). It is an X-ray diffraction profile having a diffraction peak position of the TiN (200) of the TiN film subjected to plasma treatment after film formation. It is a schematic view showing the state of the crystal lattice of the TiN film subjected to plasma treatment after film formation. Is a schematic diagram showing a state of crystals of TiN film remains deposited (as depo). It is a schematic diagram showing a state of crystals of TiN film subjected to plasma treatment after film formation. It is a diagram showing the stress in the wafer radial TiN film and a TiN film subjected to plasma treatment after deposition of the remains was deposited (the as depo) by SFD. For TiN film formed in various conditions, and those remain deposited (the as depo), for having been subjected to the subsequent plasma treatment is a diagram showing the relationship between the specific resistance of the temperature and film. For TiN film formed in various conditions, and those remain deposited (the as depo), for having been subjected to the subsequent plasma treatment is a diagram showing the stress of the relationship between the temperature and the membrane. For TiN film formed in various conditions, and those remain deposited (the as depo), for having been subjected to the subsequent plasma treatment is a diagram illustrating the specific resistance and the film stress of the relationship between the film. After forming the TiN film by the SFD, in the case of varying the treatment time was subjected to plasma treatment is a diagram showing the relationship between the processing time and resistivity, Is a diagram showing the Cl concentration in the depth direction after leaving film formation (the as depo) a 30sec plasma treatment. Is a diagram showing the O concentration in the depth direction after leaving film formation (the as depo) a 30sec plasma treatment. A TiN film in the present invention method and the conventional method is a diagram showing various process conditions and measurement results of when the film formation. A TiN film in the present invention method and the conventional method is a diagram showing various process conditions and measurement results of when the film formation. A TiN film in the present invention method and the conventional method is a diagram showing various process conditions and measurement results of when the film formation. The processing apparatus as another example of an apparatus for carrying out the method of the present invention is a cross-sectional view illustrating. Is a diagram showing various process conditions and measurement results of when the present invention method was performed. It is a diagram illustrating an example of a timing chart of the film forming method for performing stress-reducing treatment by cycles plasma during the deposition of the TiN film by SFD method in the apparatus of FIG. 21. While film formation (the as depo), illustrates and thereafter compared to that plasma treatment was performed, the specific resistance of the TiN film definitive to that performed SFD + cycle plasma four conditions. While film formation (the as depo), is a graph showing by comparison to that performed subsequent plasma treatment, the stress of the TiN film definitive to that performed SFD + cycle plasma four conditions. An example of a method of forming a capacitor including a method TiN film formed by using the present invention as an electrode is a flowchart showing. It is a process sectional view showing the steps of an example of a method method for forming a capacitor with the electrodes a TiN film formed by using the present invention. It is a plan view of (E) in FIG. 26. An example of a device equipped with a capacitor having a TiN film formed by using the method of the present invention as an electrode is a cross-sectional view illustrating.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention.

<Example of apparatus for carrying out the method of the present invention>
First, an example of a device for carrying out the method of the present invention schematically. Figure 1 is a schematic plan view illustrating the processing system as one example of an apparatus for carrying out the method of the present invention. As shown in this FIG. 1, the processing system 10 includes, as main components, and a first and second processing devices 12, 14, and a common transfer chamber 16 of substantially hexagonal shape. The processing system 10, other, has first and second load lock chamber 18A has a load lock function, and 18B, and a second transfer chamber 20 which forms an elongated shape. Specifically, the first and second processing devices 12 and 14 respectively are connected to the two sides of the substantially hexagonal shape of the common transfer chamber 16, the two sides of the opposite, first and second load lock respectively room 18A, 18B are connected.

Common between transfer chamber 16 and the first and second processing devices 12, 14, and the common transfer chamber 16 and the first and second load lock chamber 18A, between the 18B, respectively gate valve G is interposed They are, are a cluster tool of. Between these gate valves G and the first and second processing devices 12, 14 and the common transfer chamber 16, and the first and second load lock chambers 18A, 18B and communicating and possibly blocking between the common transfer chamber 16 It has become. The first and second load lock chamber 18A, also between the 18B and the second transfer chamber 20, as described later, similarly gate valve G is interposed. First preliminary second load lock chamber 18A, 18B is adapted to with the loading and unloading of the semiconductor wafer W as an object to be processed can be selectively realized its interior and atmospheric pressure and a vacuum atmosphere Further, the common transfer chamber 16 is maintained in a vacuum atmosphere.

The common transfer chamber 16, first and second load lock chambers 18A, 18B, and the access can be located in the first and second two each processing unit 12, 14, bending and stretching and pivotable articulated arm transport mechanism 22 of the structure is provided. The transfer mechanism 22 has two picks A1, A2, which can be bent and stretched independently in opposite directions, thereby making it possible to handle two wafers at a time.

The second transfer chamber 20 is formed by a box body oblong, on one side of the long sides thereof opposed, one or more to introduce a semiconductor wafer as an object to be processed, in the illustrated example 3 One of the carry-in port is provided, each inlet port, closing the door 24 is provided which is adapted to be opened and closed. Then, in correspondence to these entrance, inlet port 26 is adapted to respectively provided, can be placed one by one substrate container 28 to the inlet port 26. The substrate container 28, so that the plurality of sheets, can be accommodated in a state of being stacked in multiple stages at equal pitches, for example, 25 wafers W. The entrance transfer chamber 20 is formed downflow of clean air is set to atmospheric pressure of approximately atmospheric pressure.

The entrance transfer chamber 20, second transfer mechanism 30 for conveying along the wafer W in the longitudinal direction is provided. The second transfer mechanism 30 is slidably supported on the entrance transfer chamber 20 of the guide rails provided so as to extend along the length (not shown). The second transfer mechanism 30, bending and stretching and pivotally made the two arms 30A, has a 30B. At one end of the entrance transfer chamber 20, the orienter 32 for performing alignment of the wafer is provided, outs positioning cutting of the wafer W, for example, the position of the center of the position-direction and the wafer W in the notch or orientation flat and it is capable of detecting the amount of deviation.

On the other side of the opposite long sides of the entrance transfer chamber 20, first and second two load lock chambers 18A, 18B are connected via a gate valve G. The first and second load lock chamber 18A, the inside 18B, table 32 of smaller diameter than the wafer diameter to temporarily mounting a wafer W is installed respectively, atmospheric pressure therein so that the wafer W can be loading and unloading by using the second transfer mechanism 30 in a state in which the to.

The processing system 10 for controlling the overall operation of the processing system, and a system controller 34 comprising a computer. The system control unit 34 controls the loading of the semiconductor the wafer W, unloading operation, specific operations of the first and second processing devices 12, 14. Also, this system control unit 34, storage unit 36 ​​is connected with a storage medium for storing a program readable on a computer necessary for these operations and operations. Storage medium may be a fixed thing such as a hard disk, flexible disk, CD-ROM, DVD, or may be a portable, such as a flash memory.

Next, first processing unit 12 also to Figure 2 described with reference to. The first processing unit 12 is a device for forming a titanium nitride (TiN) film as a thin film by thermal CVD or SFD. As shown in FIG. 2, the first processing unit 12 has, for example, has been treated container 40 shaped as a cylindrical box body of an aluminum alloy or the like. This processing container 40, the bottom is provided with the mounting table 44 which is erected by struts 42 from, for example, the diameter on the upper surface of the mounting table 44 is adapted to place the semiconductor wafer W 300 mm.

The mounting table 44, the lift pins and lowering the bottom surface of the wafer W supported to when loading and unloading the wafer W (not shown) is provided. The addition in the mounting table 44, a resistance heater 46 is provided over substantially the entire surface as a heating means for heating the wafer W. Further, at one side of the process container 40, transfer port 49 is provided, this transfer port 49 is connected the common transfer chamber 16 through gate valves G, as the wafer W can be loading and unloading going on.

The ceiling portion of the processing chamber 40, a shower head 50 as a gas introducing means is provided. Showerhead 50 has a plurality of gas injection holes 48A, 48B on the lower surface, inside the shower head 50, separately compartmented diffusion chamber 52A, and 52B are formed, the gas discharge holes 48A are diffused communicating with the chamber 52A, the gas discharge hole 48B is in communication with the diffusion chamber 52B. The diffusion chamber 52A, is to 52B, so as to supply the gas separately through respective gas supply pipes 51A and 51B. Here using TiCl 4 gas as the source gas, is used NH 3 gas as the nitrogen-containing gas, TiCl 4 gas is introduced into the diffusion chamber 52A through one of the gas supply pipe 51A, the NH 3 gas and the other gas through the supply pipe 51B is introduced into the diffusion chamber 52B, respectively so as to be discharged gas discharge hole 48A, the 48B into the processing container 40.

Further, the both diffusion chamber 52A, is to 52B, N 2 gas as an additive gas also are supplied. Each gas is not shown is supplied while its flow rate is controlled by the flow controller such as a mass flow controller, also the start of the supply by opening and closing valve, so that also controls stopping. Then, these gases, so as to form a TiN film by thermal CVD or SFD without using plasma.

Further, the bottom portion of the processing chamber 40, an exhaust port 54 is provided, the vacuum evacuation system 56 is connected to the exhaust port 54. The evacuation system 56 has an exhaust passage 58 connected to the exhaust port 54, the exhaust passage 58, the pressure regulating valve 60 and a vacuum pump 62 are sequentially interposed, the processing container 40 It has to be evacuated atmosphere while the pressure adjustment. Incidentally, each unit of the first processing unit 12 is operated controlled by a command from the system control unit 34 described above.

Reference is now made also to FIG 3 for the second processing unit 14. Figure 3 is a block diagram showing a second processing unit. The second processing unit 14 is a device for subjected to plasma treatment on the TiN film formed by the first processing unit 12 previously reducing the film stress. As shown in FIG. 3, the second processing unit 14 has, for example, a has been processing container 70 formed into a cylindrical shape by an aluminum alloy or the like, the processing chamber 70 is grounded.

At the bottom of the processing container 70, and exhaust port 72 is provided for discharging the atmosphere in the vessel, an evacuation system 74 to the exhaust port 72 is connected. The evacuation system 74 has an exhaust passage 76 connected to the exhaust port 72, the exhaust passage 76, is valve opening in order to perform pressure adjustment toward the downstream side from the upstream side adjustably made pressure control valve 78 and a vacuum pump 80 are sequentially interposed. Thus, so that can be uniformly evacuated the processing container 70 from the bottom periphery.

This processing container 70, a disk-shaped mounting table 82 for example in diameter through strut 81 made of a conductive material for mounting a semiconductor wafer W of 300mm is provided. Specifically, the mounting table 82 is made of a conductive material such as aluminum alloy, also functions as a lower electrode is one of a plasma electrode. The lower electrode is grounded. As the lower electrode, the embedded conductive member in the member made of ceramic for example mesh-like AlN or the like, may be configured to ground the conductive member.

In the mounting table 82, it is embedded for example a resistance heater 84 as a heating means, while heating the semiconductor wafer W, and to be able to maintain the desired temperature it. Further, the mounting table 82, thereby lifting push up the semiconductor wafer W during the loading and unloading of the clamp ring and the semiconductor wafer W peripheral portion (not shown) fixed on the table 82 mounting it to press the semiconductor wafer W shown lifter pins are provided that do not.

The ceiling portion of the processing chamber 70, a shower head 86 as a gas introducing means for functioning as an upper electrode is the other plasma electrode is provided, the shower head 86 is provided integrally with the top plate 88 ing. Peripheral portion of the top plate 88 is mounted airtightly through an insulating material 90 with respect to the upper end of the container side wall, a shower head 86 and the processing vessel 70 are insulated. The shower head 86 is formed, for example, a conductive material such as an aluminum alloy. The lower surface of the shower head 86 a plurality of gas discharge holes 92 for discharging gas is formed. On the upper surface of the shower head 86, a gas supply pipe 93 is connected.

It is to the showerhead 86 plasma generating gas is supplied through the gas supply pipe 93. The plasma generating gas, N 2 gas, H 2 gas, NH 3 gas, can be preferably used a rare gas, it is possible to use at least one of these. As the rare gas, Ar gas is preferable. The plasma generation gas is not shown is supplied while its flow rate is controlled by the flow controller such as a mass flow controller, also the start of the supply by opening and closing valve, so that also controls stopping.

The shower head 86, as a plasma generating mechanism for generating a plasma in the processing space S between the mounting table 82 and the shower head 86, a high frequency power source 98 is connected via a feed line 94. Matching circuit 96 is provided in the middle of the feed line 94. The high frequency power source 98, for example, a frequency can be used as the 450 kHz. Here, grounded mounting table 82, but so as to apply a high frequency power to the shower head 86 is not limited to this, the high frequency power added to table 82 mounting contrary to the above, the ground showerhead 86 it may be.

Also, the sidewall of the processing chamber 70, provided transfer port 100 for loading and unloading the semiconductor wafer W is, this transfer port 100, the gate valve G was made to be opened and closed airtightly during loading and unloading of the semiconductor wafer W It is provided. Incidentally, each component of the second processing unit 14 is operated controlled by a command from the system control unit 34 described above.

<Example of deposition method of processing system 10>
Next, the film forming method of the present invention will be described with reference to FIG. 4, which is performed using the formed processing system 10 as described above. Figure 4 is a flow chart showing the steps of the film forming method according to the present embodiment. First, from the substrate container 28 placed on the inlet port 26 of the second transfer chamber 20, the unprocessed semiconductor wafer W incorporation into the interior by using the second transfer mechanism 30 conveys the semiconductor wafer W into the orienter 32 the alignment is performed. Wafer W after alignment again, first and second load lock chamber 18A by the second transfer mechanism 30, is loaded into one of the load lock chamber of the 18B.

Wafer W of the load lock chamber, after the pressure adjustment of the load lock chamber by the transfer mechanism 22 of the common transfer chamber 16, are incorporated into the common transfer chamber 16 that is maintained in advance in a vacuum atmosphere. Then, the wafer W is first carried into the first processing unit 12 the film forming process is performed (step 1), the wafer W after the film forming process is then carried into the second processing unit 14 process for reducing the stress of the film by plasma treatment Te is performed (step 2). Then, the wafer W already treated each processing is completed will be accommodated into the substrate container 28 for accommodating a wafer W reverse path following the processed of the aforementioned pathways.

Next, a description will be given of the first processing unit processes the first deposition step performed in a 12 shown in FIG. Here, it is necessary to use a step coverage is good film forming method in consideration of the fact that forming the tubular or cylindrical, such as a capacitor electrode of the DRAM, the raw material gas and a nitride without using plasma for the forming a TiN film by heat using a gas. Incidentally, the height of the lower electrode in tubular or cylindrical capacitor of DRAM is about 2 ~ 3 [mu] m, the aspect ratio is about 20-30. As a specific treatment method, a simple thermal CVD method for forming a TiN film on the raw material gas and a nitriding gas simultaneously flowed heated substrate, only the steps and the nitride gas supplying source gas and nitriding gas it can be used or the film formation by applying a step of alternately supplying, or raw material gas and a nitriding gas flowing alternately and SFD method is a thermal CVD method for forming a film suitably. Among them, relatively low temperatures, smaller and more impurities less resistivity high quality film SFD methods that can be deposited are preferred.

Will be described in detail the formation of the TiN film by SFD method.
In film formation by this SFD method, basically intermittently repeated flowing and NH 3 gas is TiCl 4 gas and the nitriding gas as a source gas, as described above, optionally the N 2 gas to these gases Add appropriate. Figure 5 is a diagram showing an example of a timing chart when forming a film of TiN film by SFD method. As shown in FIG. 5, a step S1 for forming the TiCl 4 gas and the thin film NH 3 gas flowing predetermined time as a nitriding gas as raw material gases, thin flowing NH 3 stops supplying the TiCl 4 step S2 for nitriding the film, alternately and repeatedly across the step S3 is a purge step, depositing a TiN film having a predetermined thickness. One step S1 and the step S2 is 1 cycle, sets the number of cycles by the thickness of the target. Note that step 3 is not essential the purge step.

At this time, TiCl 4 gas is introduced into the processing container 40 from the gas discharge holes 48A of the shower head 50 through the gas supply pipe 51A, NH 3 gas is gas discharge hole 48B of the shower head 50 through the gas supply pipe 51B It is introduced into the processing container 40 from. The pressure in the processing vessel 40 is maintained at a predetermined process pressure by evacuating the vacuum evacuation system 56. The wafer W placed on the stage 44 is maintained at a predetermined temperature by the resistance heater 46. Instead of the above sequence, it may be employed sequence supplying TiCl 4 gas and NH 3 gas are alternately across the purge. In this case, first, to adsorb the TiCl 4 gas on the surface of the wafer W by supplying TiCl 4 gas, TiCl 4 adsorbed by then supplying the NH 3 gas TiN was formed by nitriding, Repeat until it a desired thickness depositing a TiN film.

The process conditions when the SFD is exemplified the followings.
Process temperature: 250 ~ 1000 ℃
Process pressure: 13 ~ 1330Pa
TiCl 4 gas flow rate: 10 ~ 100sccm
NH 3 gas flow rate: 10 ~ 5000sccm
N 2 gas flow rate: 100 ~ 5000sccm
TiN is of a thickness: 1 ~ 100nm

This film deposition process, the back of the step coverage by forming a TiN film to the surface of the large recess of the aspect ratio as described above can perform good film formation. The supply mode of each gas is merely an example, and may be used known what gas supply mode. When performing the simple thermal CVD, with essentially the same conditions, NH 3 gas is TiCl 4 gas and nitriding gas as a source gas may be supplied at the same time the N 2 gas as required.

Next, a description will be given stress-reducing process by the step 2 plasma are performed in the second processing unit 14 shown in FIG. Here is subjected to plasma processing to TiN film formed by the first processing unit 12, it reduces the stress of the TiN film.

Conventionally, in forming the TiN film by thermal CVD, less impurities such as Cl, the resistivity is made to be higher deposition temperature in order to obtain a low quality film, a further lower resistivity quality Although film formation by SFD method for obtaining a relatively low temperature membranes have been proposed, the resistivity these approaches have been found to be associated stress increases the TiN film as drops. It shows the X-ray diffraction profile of the TiN film that remains deposited in FIG. As shown in FIG. 6, TiN (200) It can be seen that the peak position of is shifted to a higher angle side than the peak position of the bulk of TiN. The lattice constant of the TiN film as-deposited is 0.421Nm, less than 0.424nm is the lattice constant of the bulk of TiN was found. In other words, such an impurity such as Cl when forming a TiN film by thermal CVD escapes from a large amount of film is caused, distortion occurs in the crystal lattice as shown in FIG. 7, whereby stress on the membrane It is assumed to occur.

Therefore, to mitigate the distortion of the crystal lattice by plasma treatment after forming the TiN film reduces the film stress. It shows an X-ray diffraction profile of a TiN film after the plasma treatment in Figure 8, this as shown in the figure, and the peak position coincides with approximately the bulk of the peak position of the TiN of the TiN (200), also the lattice constant becomes a value close to 0.423nm and a lattice constant of a bulk of TiN 0.424Nm, as shown in FIG. 9, it is confirmed that the distortion of the film spreads the distorted parts of the crystal lattice is relaxed.

To explain this in crystalline level, a state that was formed, as shown in FIG. 10, which is distorted TiN crystals grown in a columnar shape, is also found unstable crystals, by plasma treatment, Fig. as shown in 11, distortion of the crystal is reduced, unstable crystals stabilized, thereby the stress of the membrane is reduced. In this case, by reducing impurities such as chlorine was present in the film by the plasma treatment, a more high-quality film. Further, by the plasma treatment, the distal end portion of the TiN crystal is etched, the surface roughness of the TiN film is reduced.

Carrying out the stress-reducing step in step 2 by plasma, into the second processing unit 14 of the processing container 70 within the gas for plasma generation is supplied at controlled flow rates through the showerhead 86, the processing container 70 within the the pressure was maintained at a predetermined pressure while evacuating by a vacuum exhaust system 74 to maintain the wafer W placed on the mounting table 82 resistance heating by the heater 84 a predetermined temperature, the shower head 86 from the high frequency power source 98 a by applying a high frequency power to generate a plasma in the processing space S between the mounting table 82 and the shower head 86.

The plasma treatment is not limited gas species as long as the gas which does not adversely affect the membrane, as described above, N 2 gas, H 2 gas, NH 3 gas, can be preferably used a rare gas, these it is possible to use at least one of. Since the effect can only rare gas is obtained, stress-reducing effect is not due to a chemical reaction is considered to be a function of the ions in the plasma. As the rare gas, Ar gas is preferable. The plasma generating gas, for example, can be suitably used one or both the Ar gas of the NH 3 gas and H 2 gas.

The process conditions of the plasma treatment is exemplified the followings.
Process temperature: 250 ~ 1000 ℃
Process pressure: 13 ~ 1330Pa
High-frequency power power: 100 to 1500 watts (W)
Plasma generating gas: Ar, H 2, NH 3
Gas flow rate: Ar gas 100 ~ 5000sccm
H 2 gas 100 ~ 5000sccm
NH 3 gas 100 ~ 5000sccm
Process Time: 1 ~ 300sec

If the process temperature is lower than 250 ° C. is made impossible sufficiently stress-reducing effect by the plasma, is higher than 1000 ° C., the characteristic elements of the base that is formed in the previous step in the wafer W is deteriorated put away. The preferred range of process temperature is 300 ~ 850 ° C.. Further, when the process time is less than 1sec it can not effect sufficiently exhibited plasma treatment, and since if longer than 300sec is saturated the effect of the plasma treatment, a decrease in throughput occurs.

The plasma treatment, as a result of the stress of the TiN film is reduced, it is possible to solve the various problems which have been caused by stress of the TiN film. For example, to reduce the warp of the semiconductor wafer itself not only it is possible to suppress the defocus at the time of photolithography, the adsorption by the clamp or an electrostatic chuck of the wafer itself can be reliably performed. Also it is possible to prevent the cylindrical or cracks and breaks of the lower electrode and the upper electrode in a cylindrical capacitor, or breakage or the like of the support bars to support these.

Indeed the results of measurement of the stress of the TiN film shown in FIG. 12. Here, at 680 ° C. 5 cycles of SFD (Condition A), 480 ° C. for 12 cycles of SFD (condition B), by performing film formation in three conditions of 400 ° C. at 20 cycles of SFD (Condition C) 12 nm and that of the TiN film while depositing the (the as depo), the stress was measured were subjected to plasma treatment to those films, showing a radial stress of the wafer in FIG. The plasma treatment conditions at this time, Ar, and H 2, NH 3 gas used as the plasma generation gas to the high-frequency electric power is 800 W, the processing time 120 sec, the same temperature as when the temperature of the film forming process. As shown in this figure, by forming a film after the plasma treatment, it can be seen that stress is reduced. In this, the stress tension in hot condition A is changed to compressive stress.

Also, the TiN film deposited under various conditions, and those remain deposited (the as depo), for having been subjected to the subsequent plasma treatment were measured stress and resistivity of the film. The results are shown in FIGS. 13-15. In the plasma treatment in the same manner as described above conditions, it was carried out in the film forming process and the same temperature. Figure 13 is a diagram showing FIG, 14 is a diagram showing a relationship between stress temperature and the membrane, Figure 15 is the specific resistance and stress of the relationship between film showing the relationship resistivity of temperature and film.

As shown in FIG. 13, if left deposition, although the ratio in the thermal CVD 460 ° C. resistance is very high value specific resistance of the membrane decreases significantly with increasing temperature, the resistivity of the film even at a low temperature in the SFD Although low, also the resistivity with increasing temperature decreases. Film stress at this time is as shown in FIG. 14, increases as the temperature increases, as shown in FIG. 15, the stress of the film, it can be seen that the resistivity increases as decreases.

In contrast, for those subjected to plasma treatment, specific resistance with stress is reduced decreases, the ability to achieve both stress-reducing and resistivity decreases were confirmed by performing plasma treatment after the film formation process. Component elements were SFD at 480 ° C., although changes from the tensile stress in the compression stress by performing plasma treatment, if dislike the compression stress, the stress by changing the conditions of the plasma treatment it can be close to zero.

After forming a TiN film having a thickness of 12nm performed SFD 30 cycles at 680 ° C., Ar and H 2, NH 3 gas used as the plasma generating gas, a high frequency power power as 800 W, during the film forming process temperature the same 680 ° C. and, by changing the processing time to grasp the change in the specific resistance. The results are shown in Figure 16. As shown in this figure, it can be seen that the resistivity in the stage of up to about 50sec is rapidly lowered. Deposition remains in FIG 17A (as depo) and 30sec plasma processing represents Cl concentration in the depth direction after, remained deposited in FIG. 17B (as depo) 30sec plasma treatment in the depth direction of the after O shows the concentration. As shown in these, by performing plasma treatment after film formation, impurity concentration was confirmed to be reduced.

Although it is possible to reduce the stress of the TiN film by the plasma treatment as described above, the stress of the film have different levels required by the application, not only to reduce the stress of the film, the film stress control may be desirable. Stress such TiN film can be controlled by adjusting the conditions in the plasma treatment. Specifically, by changing the temperature or time of the plasma treatment, it is possible to control the stress of the relative ease film.

The above has been shown an example in which reduced by stress plasma treatment of the membrane after forming a TiN film by thermal CVD (SFD including), stress-reducing process by the plasma treatment, W by thermal CVD film is also effective in the case of forming a. Specifically, the raw material gas, for example, a WF6 gas, reducing gas, for example, using of H2 gas, but the stress in the film even when forming these the W film is supplied to the heated substrate occurs, in this case also it is possible to reduce the stress by plasma treatment.

<Evaluation 1 of the method of the present invention>
Next, the film deposition method of the present invention actually performs formation and plasma treatment of the TiN film with a result of measurement for the properties will be described in detail with reference. Figure 18 is a graph showing measurement results with various process conditions when performing the present invention method. Here, for comparison, also the measurement result of the TiN film formed by a conventional film forming method are also shown.

Here were conventional as described as the run name Methods 1 to 4 and the method of the present invention 1-4 in Figure 18. Deposition of TiN films, here is using all SFD method, number of repetitions are described as "cycles". For conventional methods to measure the properties of the TiN film itself formed by SFD method, in the present invention method is to measure the characteristic after performing plasma processing, wherein the further the present invention in the TiN film. Number conventional method and the present invention a method of the same run name correspond to each other. Process temperature during the evaluation 1, TiN film formation (set temperature) are two types of 480 ° C. and 680 ° C.. The plasma treatment time for process temperature (set temperature) is 450 ° C..

The difference between Method 1 and Method 2, compared method 1 that is ten cycles, the method 2 is a point where the number of cycles and 32 by shortening the period of one cycle, is actually formed film the thickness is set to be substantially the same thickness of about 7.5 ~ 8.2 nm. The difference between Method 3 and Method 4, one cycle of with different number of cycles to 13 and 6 in the same as each other, and 24.7 ~ 26.3nm thickness is formed accordingly 12. It is made different in the 2 ~ 12.5nm.

All process pressure in the plasma treatment is 667 Pa, all the process time is 120 sec. For TiN film formed in the manner described above, the film thickness, the resistance (Rs), stress, resistivity and (Rv) was measured to determine respective average values ​​(Ave.).

As apparent from FIG. 18, when comparing the conventional method 1 and the present invention method 1, even though the film thickness is substantially the same as 7.5nm and 7.4 nm, the resistance from 937.5Ω 278.0Ω to have significantly reduced the resistivity also 703.9μΩcm together is greatly reduced to 207.0Myuomegacm. Furthermore, the stress is greatly reduced to -0.1GPa from 1.4 GPa, it is understood that the stress becomes substantially zero Method 1 of the present invention have shown good results.

Comparing with the conventional method 2 and the present invention method 2, and as a result, the film thickness by increasing the number of cycles with a shorter period of one cycle than the case of the method 1 and substantially the same manner as the above method 1 . In this case also, the same effect as the above-mentioned method 1.

That is, when comparing with the conventional method 2 and the present invention method 2, even though the film thickness is the same as 8.2 nm, the resistance is also specific resistance with is reduced significantly to 273.9Ω from 456.5Omu 372 It has declined to 225.5μΩcm from .9μΩcm. Stress is also greatly reduced from 1.8GPa to -0.9GPa, the present invention method 2 it can be seen that show good results.

Next, comparing with the conventional method 3 and the method of the present invention 3, even though the film thickness is substantially the same as the 24.7 ~ 26.3nm, resistance is considerably reduced to 35.9Ω from 47.1Ω It has been significantly reduced to 94.5μΩcm from specific resistance 116.2μΩcm with there. Furthermore, stress has been significantly reduced to 0.8GPa from 2.1 GPa, the present invention method 3 stress becomes substantially zero is seen that have shown good results.

Then, comparing the conventional methods 4 and the method of the present invention 4, even though the film thickness is substantially the same as 12.2nm and Contact 12.5 nm, the resistance is reduced considerably to 83.2Ω from 121.4Ω and that although the specific resistance is considerably reduced from 148.0μΩcm to 103.8Myuomegacm. Moreover, the stress is greatly reduced to -0.1GPa from 1.9 GPa, it is understood that the stress becomes substantially zero invention method 4 shows good results.

Thus, the method invention, it was confirmed that it is possible to reduce the stress of the thin film formed on the surface of the object.

<Evaluation 2 of the method of the present invention>
Figure 19 is a graph showing the measurement results with various process conditions when performing the present invention method. Here, for comparison, also the measurement result of the TiN film formed by a conventional film forming method are also shown. Arrows "←" shown in Figure 19 shows that the same value as the value of its left.

Here, it was present process 5-8 to the conventional method 5-8 as described as the run name in Figure 19. Deposition of TiN films, here is used all SFD method are all as is set forth as a number of repetitions "cycles" 13. For conventional methods to measure the properties of the TiN film itself formed by SFD method, in the present invention method is to measure the characteristic after performing plasma processing, wherein the further the present invention in the TiN film. Number conventional method and the present invention a method of the same run name correspond to each other. Process temperature during the evaluation 2, TiN film formation (set temperature) is 680 ° C.. The plasma treatment time for process temperature (set temperature) is 640 ° C..

The difference between Method 5 and Method 6, and differences in the way 7 to the method 8, while the hydrogen-containing gas during the process 5,7 plasma treatment is NH 3 gas and H 2 gas, the method 6,8 in (19, flow rate of the NH 3 plasma process is being reduced to zero) point hydrogen-containing gas is H 2 gas in. The difference between the methods 5,6 and methods 7,8 also methods 5 and 6 are plasma treated in Insitu, methods 7 and 8 lies in the fact that the plasma treatment in ex-situ. Note refers to be carried out in a vacuum continuously film forming process and the plasma process to herein as Insitu, ex-situ once put into the atmosphere of the wafer after performing film forming process and, to a plasma treatment after that in again vacuo say that. Note plasma treatment preceding the present invention methods 1 to 4 are performed at Insitu.

All process pressure in the plasma treatment is 667 Pa, all the process time is 120 sec. For TiN film formed in the manner described above, the film thickness, the resistance (Rs), measured stress, resistivity and (Rv), was determined value at the center (center) of each of the semiconductor wafer W.

Comparing the present invention method 5 with the conventional method 5, even though the film thickness is substantially the same as 10.3nm and 10.4 nm, the resistance is considerably reduced to 79.3Ω from 139.7Omu, It has been significantly reduced from the specific resistance 145.0μΩcm to 81.5μΩcm. Moreover, the stress is greatly reduced to -0.4GPa from 1.8 GPa, the present invention method 5 it is seen that have shown good results.

Next, comparing with the conventional method 6 and the method of the present invention 6, even though the film thickness is substantially the same as 10.3nm and 10.4 nm, the resistance is considerably reduced to 87.0Ω from 139.7Ω together they are, are considerably reduced specific resistance from 145.0μΩcm 92.8 "to .mu..OMEGA.cm. Moreover, the stress is greatly reduced to -0.6GPa from 1.8 GPa, the present invention method 6 good it can be seen that shows the results.

Comparing with the conventional method 7 and the process of the present invention 7, even though the film thickness is substantially the same as 10.4nm and 10.6 nm, the resistance is considerably reduced to 93.0Ω from 139.7Omu, It has been significantly reduced from the specific resistance 145.0μΩcm to 98.6μΩcm. Moreover, the stress is greatly reduced to -0.7GPa from 1.8 GPa, the present invention method 7 it can be seen that show good results.

Comparing the present invention a method 8 with the conventional method 8, even though the film thickness is the same as the 10.4 nm, resistance together are considerably reduced to 80.3Ω from 139.7Omu, specific resistance 145. It has been significantly reduced to 83.1μΩcm from 0μΩcm. Moreover, the stress is greatly reduced to -0.4GPa from 1.8 GPa, the present invention method 8 it can be seen that show good results.

Thus, in the plasma processing, be different from the method of gas composition and process, it was confirmed that the reduced stress of the TiN film.

Further, in the process temperature the temperature range of 640 ° C. of the present invention a method 5-8 from 450 ° C. of the present invention methods 1 to 4 during the plasma treatment, it was confirmed that can reliably exhibit the effects of the plasma treatment.

<Evaluation 3 of the method of the present invention>
Next, using the deposition method of the present invention will be described with results of evaluation of the measurement for the properties was carried out by performing a plasma treatment on the tungsten (W) film is the same high melting point metal and Ti. Figure 20 is a graph showing measurement results with various process conditions when performing the present invention method. Here, for comparison, measurement results of the W film formed by a conventional film forming method also are shown together. Arrows "←" shown in FIG. 20 shows that the same value as the value of its left.

Here, were traditional methods 9-10 the present invention a method 9-10 as are described as the run name in Figure 20. Deposition of the W film is here WF 6 gas as the source gas, H 2 gas as the reducing gas, Ar gas was used as a diluent gas, using a thermal CVD method to obtain a predetermined thickness by passing all gases simultaneously there. For conventional methods to measure the properties of the W film itself formed by thermal CVD method, in the present invention method is to measure the characteristic after performing is characteristic plasma treatment of the present invention further to the W film . Number conventional method and the present invention a method of the same run name correspond to each other. W during film formation process temperature (set temperature) is 450 ° C., the process temperature (set temperature) at the time of plasma processing is also 450 ° C..

The difference between the methods 9 and method 10, while hydrogen-containing gas in the method 9 is NH 3 gas and H 2 gas, the point a hydrogen-containing gas in the process 10 is H 2 gas (in FIG. 20, the plasma flow rate of the NH 3 treatment is in it are) zero.

All process pressure in the plasma treatment is 667 Pa, all the process time is 120 sec. For W film formed as described above, the film thickness, the resistance (Rs), stress, measurement of specific resistance (Rv), was determined value at the center (center) of each wafer W.

Comparing the present invention a method 9 to a conventional method 9, the film thickness is the same as 46.3Nm, resistance have slightly larger to 3178.5Ω from 2847.5Omu, specific resistance from 13.2Myuomegacm 14 it is the same tendency as to .7μΩcm. However, stress is reduced to 0.7GPa from 1.2 GPa, the present invention method 9 it can be seen that show good results.

Then, comparing the present invention method 10 and the prior art method 10, the film thickness is substantially the same as 46.4nm and 46.6Nm, resistance is the same as 2675.1Ω Both specific resistance 12.4μΩcm and it is substantially the same as 12.5μΩcm. However, stress is reduced to 0.8GPa from 1.1 GPa, the invention process 10 it can be seen that show good results.

Thus, in the case of the tungsten film formed by thermal CVD also, it was confirmed that it is possible to reduce the stress of the film by performing plasma treatment.

<Another example of a device for carrying out the method of the present invention>
Next, another example of an apparatus for carrying out the method of the present invention schematically. Here will be described the processing apparatus capable of performing both stress-reducing process by the film deposition process and the plasma in one treatment vessel. Figure 21 is a sectional view showing a processing apparatus as another example of an apparatus for carrying out the method of the present invention. The processor 110 is the same as the basic configuration processing apparatus 12 is obtained by adding a plasma generating mechanism for generating a plasma in the configuration, is the same as the processing unit 12 are denoted by the same reference numerals description thereof will be omitted.

That is, the ceiling portion of the processing chamber 40 of the processing device 110, as a plasma generating mechanism for generating a processing plasma in the space S 'between the mounting table 44 and the shower head 50, a high frequency power source 120 is feed line 122 It is connected via a. Therefore, the shower head 50 to which the high-frequency power is applied through the ceiling portion of the processing chamber 40 serves as an upper electrode. Matching circuit 124 is provided in the middle of the feed line 122. The high frequency power source 120, for example, frequency can be used for 450 kHz. On the other hand, the mounting table 44 is made of a ceramic member such as AlN, the lower electrode 130 in the mounting table 44 made of a mesh-like conductive member for example are embedded. And an insulating material 131 is provided hermetically between the upper end portion of the ceiling portion and the processing vessel 40 sidewall of the processing chamber 40, a shower head 50 serving as the upper electrode and the process vessel 40 are insulated. As the plasma generation gas, it is possible to use NH 3 gas, as another plasma generating gas, H 2 gas, Ar gas may permit supplied through the gas supply pipe 51B. Also, here grounded lower electrode 130, but so as to apply a high frequency power to the shower head 50 is not limited to this, a high frequency power was added to the lower electrode 130 contrary to the above, the ground showerhead 50 it may be. Also within the mounting table 44, a resistance heater 46 is embedded as the heating means, so that the table 44 can be controlled to a desired temperature.

<Example of deposition method of processing apparatus 110>
It will now be described a film forming method of the present invention which is performed using the processing device 110.
Here, it is possible to perform the steps 1 and 2 in the flow chart of FIG. 4 in the processing chamber 40.

First, supplying a source gas (e.g., TiCl 4 gas) and nitriding gas (e.g. NH 3 gas) are simultaneously passed simple thermal CVD method to form a TiN film on a substrate which is heated or the raw material gas and a nitriding gas, the SFD method is a thermal CVD method for forming a film by supplying step and whether gas nitriding only by passing alternately supplying a film is formed, or the raw material gas and a nitriding gas into alternating recesses of the wafer W a TiN film is formed on. Condition at this time is the same as the conditions during deposition of the first processing unit 12 described above.

Then, the supply while mounting the wafer W on the mounting table 44, after gas is stopped purging the inside of the processing chamber 40 for film formation, the plasma generating gas through the showerhead 50 into the processing container 40 the inside of the processing vessel 40 is set to a predetermined pressure while, applying high-frequency power from the high frequency power supply 120 to the shower head 50. Thereby, plasma is generated in the processing space S 'between the mounting table 44 and the shower head 50, the plasma processing is applied to the wafer W. At this time, if the temperature during the plasma treatment is different from the temperature when the film formation process, to change the set temperature of the mounting table 44.

The plasma generating gas, as in the second processing unit 14 described above, N 2 gas, H 2 gas, NH 3 gas, can be preferably used a rare gas, using at least one of these be able to. The use of NH 3 gas, N 2 gas as a plasma generating gas, only enough gas for film formation, there is no need to add gas supply system for plasma generation. As in the second film forming apparatus 14, when using one or both the Ar gas of the NH 3 gas and H 2 gas, it is necessary to add the supply system of the Ar gas and H 2 gas.

Conditions during the plasma treatment is similar to the conditions in the second processing unit 14 essentially above. Further, TiN film after the plasma treatment, as in the case of treatment with the second processing unit 14, and that stress is reduced.

In the processing apparatus 110, without conveying the the wafer W, and the film deposition process of the TiN film, is performed in batch followed the stress-reducing treatment by plasma, it is possible to increase the throughput of the process. However, if the set temperature in the film forming process and the plasma treatment are significantly different, it takes time to temperature change, it is advantageous for the processing system 10.

Next, another deposition method using the processing device 110.
The film forming method is performed simultaneously plasma treatment during the deposition of the SFD described above. Figure 22 is a diagram showing an example of a timing chart when simultaneously plasma treatment during the deposition of the SFD. As shown in FIG. 22, a step S11 of forming the TiCl 4 gas and the thin film NH 3 gas flowing predetermined time as a nitriding gas as raw material gas, while flowing NH 3 stops supplying the TiCl 4 RF and from the power source 120 by applying a high frequency power to generate plasma of step S12 of performing nitriding treatment and plasma treatment simultaneously, alternately and repeatedly across the step S13 the purge step, depositing a TiN film having a predetermined thickness . One in step S11 and step S12 is one cycle, and sets the number of cycles by the thickness of the target. NH 3 gas in step S12, also serves as a gas nitriding and plasma generating gas. Note that step 13 is not essential the purge step.

Instead of such a sequence, performing the steps of adsorbing the TiCl 4 gas on the surface of the wafer W by supplying TiCl 4 gas, nitriding to generate plasma while supplying NH 3 gas and plasma treatment simultaneously and a step may be employed a sequence repeated until the desired film thickness.

According to such a deposition method, immediately after the thin TiN film is formed in step S11, stress-reducing treatment by plasma is performed on the film in step S12, to repeat this, more effectively TiN film it is possible to obtain a lower specific resistance film can reduce the stress. Further, by varying the plasma processing time and the number of cycles of step 12, it is also possible to control the stress of the TiN film to a desired value. Incidentally, a method of generating a plasma cyclically in synchronism with the intermittent supply of gas such SFD, also referred to hereinafter SFD + cycle plasma.

Indeed, the characteristics of the case of forming in such SFD + cycle plasma, while deposition (the as depo), and after the above SFD as compared with the case of film formation by plasma treatment (SFD + plasma treatment) explain. Here, the temperature during the SFD deposition of the underlying and 480 ° C., the conditions of the subsequent plasma treatment, Ar as the plasma generation gas, a H 2, NH 3 gas, 800 W high frequency power power, processing time 5sec, was 480 ℃ temperature. Further, SFD + cycle plasma changes the time and number of cycles of steps 12, 3 seconds × 10 cycles (conditions 1), 3 seconds × 20 cycles (conditions 2), 3 seconds × 30 cycles (conditions 3), 10 seconds It was performed at × 30 cycles (condition 4). the as depo, SFD + plasma treatment, and the specific resistance of the formed TiN film under the conditions 1-5 SFD + cycle plasma 23 shows the stress in Figure 24. As shown in FIG, SFD + cycle plasma is present film forming method, SFD + plasma treatment becomes more lower resistance than it can be seen that the higher the effect of reducing stress. Further, by increasing the processing time of the number of cycles or steps 12, the effect of reducing the effects and stress lowering the specific resistance seen be further improved.

<Method of forming a capacitor>
A method for forming a capacitor is performed using a film forming method of the present invention will be described with reference to FIGS. 25 and 26. Figure 25 is a flow chart showing the steps of the method for forming a capacitor according to the present invention, FIG. 26 is a partially enlarged cross-sectional view of a portion of a wafer in each step of the method for forming a capacitor. Incidentally, in FIG. 26, the lower structure formed on the semiconductor wafer W before forming the capacitor are omitted.

First, as shown in (A) of FIG. 26, in the interior of the semiconductor the wafer W, the contact 142 made of, for example, Ti or the like so as to correspond to the position for forming a capacitor are formed in advance. The contacts 142 are two-way, for example, by arranging in a matrix a plurality (number) number provided vertically and horizontally. Then, the insulating layer 150 is formed on the surface of the wafer W for example of SiO 2 or the like. This middle of the thickness direction of the insulating layer 150 is laminated such support bar insulating film 152 serving as a support bar is embedded as will be described later. The support bar insulating film 152 is previously patterned, for example, in a lattice shape so as to intersect on the contact 142. The support bar insulating film 152, a different material from the insulating layer 150, for example, SiN or the like is used.

For such semiconductor the wafer W, by etching as shown in (B) of FIG. 26, by removing the insulating layer 150 and the support bar insulating film 152 in the portion corresponding to the respective contacts 142 recess 154 to form (step 11). Thus, exposing the contact 142 to the bottom of the recess 154. As described above, the recess 154 is so provided in correspondence with each contact 142 will be provided a plurality on the surface of the wafer W. The height of the recess 154 is the aspect ratio was about 2 ~ 3 [mu] m is about 20-30, and has a very elongated recess.

Then, the entire surface of the insulating layer including the surface within the recess 154, as shown in (C) of FIG. 26, forming a first thin film 156 composed of TiN film with a predetermined thickness (step 12 ). The In forming the first thin film 156 is stress reduced using the deposition method described above, and specific resistance smaller so that the quality of the TiN film is formed. Here it is electrically connected to the first thin film 156 and the contact 142 formed of TiN film.

Then, By thus first performed on the wafer W on which the thin film 156 is formed, for example, CMP to (Chemical Mechanical Polishing) abrasive, as shown in FIG. 26 (D), the surface of the insulating layer 150 ( a first thin film 156 formed on the upper surface) is removed, thereby leaving the first thin film 156 formed on the surface within the recess 154 (step 13).

Then, for example, by etching treatment using hydrofluoric acid or the like, to remove only the insulating layer 150 (step 14). Thus, as shown in FIG. 26 (E), the first film 156 left the remains as tubular projections, it will form a lower electrode 158, the periphery thereof, insulating support bars It will remain in the state in which film 152 is bonded as a support bar 160. Shows a plan view of FIG. 26 (E) in FIG. 27, the periphery of the lower electrode 158 extends the support bar 160 in four directions, connected to each other by the lower electrode 158 to each other each support bar 160 mutually adjacent in the vertical and horizontal It is adapted to support each other is.

Next, as shown in FIG. 26 (F), to form a high dielectric constant film 162 on the entire surface of the wafer W including the inner and outer surfaces of the lower electrode 158 is a cylindrical projection with a predetermined thickness (step 15). As the high dielectric constant film 162, the dielectric constant, for example, using 10 or more materials. As this material may be, for example, HfO 2, HfZrO, the ZrO 2 or the like.

Thus, if the formation of the high dielectric constant film 162, forming a second thin film 164 composed of TiN film on the entire surface of the wafer W including the inner and outer surfaces of the high dielectric constant film 162 at a predetermined thickness to (step 16). The time of the second thin film 124 is formed is reduced stress using the deposition method described above and the specific resistance is small quality TiN film is to be formed.

Next, by etching process, a second thin film 164 in the portion other than the portion corresponding to the lower electrode 158 is a cylindrical projection removes high dielectric constant film 162, shown in FIG. 26 (H) as such, it remaining portion becomes an upper electrode 166 of the second thin film 164, the lower electrode 158, a capacitor 168 composed of a high dielectric constant film 162, and the upper electrode 166. a number, are formed in a state of being separated from each other and made (step 17).

Next, a description of such capacitors an example of a device structure applied to the capacitor in a DRAM memory cell. Figure 28 is a sectional view showing such a device structure. Incidentally, in FIG. 28, the support bar is omitted. As shown in FIG. 28, for example in the region partitioned by a field oxide film 180 on a semiconductor substrate 170 made of a silicon substrate, a gate electrode 184 through the gate insulating film 182 is formed. Further, the main surface of both sides of the semiconductor substrate 170 of the gate electrode 184, the impurity regions (source-drain region) 186 are formed by ion implantation or the like using the gate electrode 184 as a mask. On the gate electrode 184 is an interlayer insulating film 188 is formed over the main the entire surface of the semiconductor the wafer W, the contact plugs 190 to connect to a predetermined position of the interlayer insulating film 188 to one of the source and drain regions 156 are formed ing.

Bit line 192 is connected to the contact plug 190. On the interlayer insulating film 188 including the bit line 192, interlayer insulating film 194 is formed, a contact plug 142 for connection to the other of the source and drain regions 156 are formed through the interlayer insulating film 188 and 184 there. Then, on the contact plug 142, cylindrical or cylindrical capacitor 168 described above is formed.

Such capacitor 168 includes a lower electrode 158 and upper electrode 166, both will be stress is formed at a reduced TiN film, as a result, it is possible to prevent the warpage of the wafer W itself is generated not only can prevent or cracked capacitor 168 itself, that cracked. It should be noted that the support bar is not essential in the capacitor.

<Other applications of the present invention>
In the above embodiment, although the present invention shows an example applied to the TiN film and the W film, the present invention is not limited thereto, widely Ti, W, Ta, Ni, Hf, Zr, a refractory metal film and those of the nitride film of Ru or the like, and also the compound film of the plurality of materials can be applied.

In the above embodiment has been described as an example where a TiN film is used for the electrode of the capacitor structure, not limited thereto, it can be applied to a wiring such as a contact 142,190 and the bit line 192, for example in FIG. 28, shown a further layer of contacts that are not, can be applied to the global wirings.

Further, in the above embodiment, although the ones of the capacitive coupling type using a high frequency power generated from the high frequency power source 98 as a plasma generating means is not limited to, using a microwave source, generated from this and method and that formed by introducing into the microwave antenna from the processing vessel of the plasma microwave was, may be used as inductively coupled.

Furthermore, here has been described as an example a semiconductor wafer as an object to be processed, other silicon substrate to the semiconductor wafer, GaAs, SiC, also includes a compound semiconductor substrate such as GaN. Further, not limited to a semiconductor wafer, also possible to apply the present invention to a glass substrate or a ceramic substrate, or the like used in a liquid crystal display device.

Claims (21)

  1. Forming a titanium nitride film on a substrate to be processed by heat treatment by supplying the substrate to be processed in the raw material gas and a nitrogen-containing gas and a process vessel containing titanium,
    And a performing a process of reducing the stress of the film by the plasma relative to the titanium nitride film, a film formation method.
  2. Formation of the titanium nitride film, a first step of supplying the raw material gas and the nitriding gas simultaneously on a substrate to be processed, a second step of supplying a stop to gas nitriding the supply of the raw material gas to the substrate to be processed It is performed by repeating the alternating deposition method according to claim 1.
  3. The formation of the titanium nitride film, the is performed by repeating the raw material gas supplied and the supply of the nitriding gas are alternately, film forming method according to claim 1.
  4. Purging the processing chamber between said first step and said second step, film formation method according to claim 3.
  5. The temperature during the formation of the titanium nitride film is set in the range of 250 ~ 1000 ° C., film forming method according to claim 1.
  6. The raw material gas is TiCl 4 gas, the nitrogen-containing gas is NH 3 gas, film forming method according to claim 1.
  7. Temperature during the process of reducing the stress of the film by the plasma is in the range of 250 ~ 1000 ° C., film forming method according to claim 1.
  8. Process for reducing the stress of the film by the plasma, N 2 gas as a plasma generating gas, H 2 gas, NH 3 gas, using at least one selected from the group consisting of noble gases, formed of claim 1 film forming method.
  9. Processing is performed in the same processing chamber, the film forming method according to claim 1 for reducing the stress of the membrane due to the formation of the titanium nitride film plasma.
  10. The raw material gas is TiCl 4 gas, the nitrogen-containing gas is NH 3 gas, the plasma generating gas is NH 3 gas, film forming method according to claim 9.
  11. Controlling the stress of the film by adjusting the temperature and / or time in the process of reducing the stress of the film by the plasma film forming method according to claim 1.
  12. The titanium nitride film constitutes an electrode of a capacitor, the is formed in a recess formed in a surface of the substrate, film forming method according to claim 1.
  13. Wherein the surface of the substrate body is one of the electrodes is formed of the capacitor which is formed in a cylindrical shape, the titanium nitride film as the other electrode is deposited over the dielectric film thereon the deposition method of claim 12.
  14. A first step of forming a titanium nitride film on a substrate to be processed by heat treatment by supplying the substrate to be processed in the raw material gas and a nitrogen-containing gas and a process vessel containing titanium,
    And simultaneously nitriding said titanium nitride film by supplying the nitrogen-containing gas to stop the supply of the raw material gas, are alternately repeated and a second step of generating a plasma to reduce the stress of the membrane into the processing chamber, film formation method.
  15. Purging the processing chamber between said first step and said second step, film forming method according to claim 14.
  16. Wherein the temperature of the first step and the second step is in the range of 250 ~ 1000 ° C., film forming method according to claim 14.
  17. The raw material gas is TiCl 4 gas, the nitrogen-containing gas is NH 3 gas, film forming method according to claim 14.
  18. Gas for generating the plasma is NH 3, film forming method according to claim 17.
  19. By adjusting the time and / or number of cycles of the second step, to control the stress of the film, film forming method according to claim 14.
  20. And forming a tungsten film on a substrate to be processed by heat treatment by supplying the substrate to be processed in the processing chamber and a raw material gas and a reducing gas containing tungsten,
    And a performing a process of reducing the stress of the film by the plasma relative to the tungsten film, the film forming method.
  21. A method of forming a capacitor for forming a capacitor on the surface of the substrate,
    And forming a plurality of recesses the surface of the insulating layer provided on the surface of the substrate,
    On the surface of the insulating layer including the surface of the plurality of the recesses, the material gas and the nitrogen containing gas and the treated titanium nitride film on a substrate to be processed by heat treatment by supplying the substrate to be processed in the container containing titanium and forming form to, and the first thin film made of a titanium nitride film by using a film forming method having the applying process of reducing the stress of the film by the plasma relative to the titanium nitride film,
    And removing said first thin film of the surface of the insulating layer so as to leave the first film surface in the plurality of recesses,
    And to leave said first thin film as cylindrical projections by removing the insulating layer,
    Forming a high dielectric constant film on the entire surface including the surface of the remaining tubular projections,
    On the surface of the high dielectric constant film, and forming a raw material gas and a nitrogen containing gas and a titanium nitride film on a substrate to be processed by heat treatment by supplying the substrate to be processed in the processing chamber containing titanium, the nitride and forming a second thin film made of a titanium nitride film by using a film forming method having the applying process of reducing the stress of the film by the plasma relative to the titanium film,
    And forming a plurality of capacitors electrically isolating the high dielectric constant film and the second thin film remaining between the plurality of cylindrical projections are removed by etching,
    Method of forming a capacitor having a.
PCT/JP2010/069125 2009-11-04 2010-10-28 Film forming method and method for forming capacitor WO2011055671A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014062295A (en) * 2012-09-20 2014-04-10 Hitachi Kokusai Electric Inc Semiconductor device manufacturing method, substrate treatment method, substrate treatment apparatus and program

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001507514A (en) * 1995-06-05 2001-06-05 マテリアルズ リサーチ コーポレーション Plasma enhanced annealing titanium nitride
JP2002299283A (en) * 2001-03-30 2002-10-11 Toshiba Corp Manufacturing method for semiconductor device
JP2004263207A (en) * 2003-02-20 2004-09-24 Tokyo Electron Ltd Film deposition method
JP2011006783A (en) * 2009-05-25 2011-01-13 Hitachi Kokusai Electric Inc Method of manufacturing semiconductor device and substrate processing apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001507514A (en) * 1995-06-05 2001-06-05 マテリアルズ リサーチ コーポレーション Plasma enhanced annealing titanium nitride
JP2002299283A (en) * 2001-03-30 2002-10-11 Toshiba Corp Manufacturing method for semiconductor device
JP2004263207A (en) * 2003-02-20 2004-09-24 Tokyo Electron Ltd Film deposition method
JP2011006783A (en) * 2009-05-25 2011-01-13 Hitachi Kokusai Electric Inc Method of manufacturing semiconductor device and substrate processing apparatus

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014062295A (en) * 2012-09-20 2014-04-10 Hitachi Kokusai Electric Inc Semiconductor device manufacturing method, substrate treatment method, substrate treatment apparatus and program

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