JP2005243845A - Substrate treatment method and substrate treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To protect wiring by selectively covering the exposed surface of the wiring with a wiring protective film improved in a barrier property to the wiring. <P>SOLUTION: At the time of protecting the wiring formed on the surface of a substrate by selectively forming the protective film on the exposed surface of the wiring, pre-treatment is performed on the base surface to be plated of the substrate, and the protective film is selectively formed on the pre-treated base surface to be plated of the substrate by performing electroless plating. Then the electroless-plated substrate is cleaned and dried and plasma treatment is performed on the surface of the dried substrate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus, and in particular, exposure of wiring formed by embedding a metal (wiring material) such as copper or silver in a fine concave portion for wiring formed on the surface of a substrate such as a semiconductor wafer. The present invention relates to a substrate processing method and a substrate processing apparatus used for selectively forming a wiring protective film on a surface and protecting the wiring.

  As a wiring formation process of a semiconductor device, a process (so-called damascene process) in which metal (wiring material) is embedded in wiring grooves and contact holes is being used. This is because, after embedding a metal such as copper or silver in a wiring groove or contact hole previously formed in an interlayer insulating film, the excess metal is removed by chemical mechanical polishing (CMP) and planarized. Process technology.

  For this type of wiring, for example, copper wiring using copper as a wiring material, in order to improve reliability, to prevent thermal diffusion of wiring (copper) to the interlayer insulating film and to improve electromigration resistance In order to prevent the wiring (copper) from being oxidized in an oxidizing atmosphere when a barrier film is formed on the bottom and side surfaces of the wiring, and then an insulating film (oxide film) is laminated to make a semiconductor device having a multilayer wiring structure. A method of forming an antioxidant film on the entire surface of the substrate is employed. Conventionally, a metal such as tantalum, titanium, or tungsten or a nitride thereof has been generally employed as this type of barrier film, and a silicon nitride or the like has generally been employed as an antioxidant film.

However, in this case, the barrier film and the antioxidant film are different from each other, so that the wiring metal thermal diffusion prevention, thermal migration resistance, and electromigration resistance may not be sufficiently obtained.
For this reason, as an alternative to this, recently, the exposed surface of the wiring is selectively covered with a wiring protective film (cover material) made of Co alloy, Ni alloy, etc., and thermal diffusion, electromigration and oxidation of the wiring are performed. Prevention is under consideration. The wiring protective film made of Co alloy, Ni alloy or the like is obtained by electroless plating, for example.

Here, for example, as shown in FIG. 1, a wiring groove 4 is formed inside an insulating film 2 made of SiO ₂ or the like deposited on the surface of a substrate W such as a semiconductor wafer, and a barrier layer 6 made of TaN or the like on the surface. After forming, for example, copper plating is performed to form a copper film on the surface of the substrate W and embedded in the wiring groove 4, and then CMP (chemical mechanical polishing) is performed on the surface of the substrate W. By flattening, a wiring 8 made of a copper film is formed inside the insulating film 2, and the surface of the wiring (copper film) 8 is made of, for example, a Co—WP alloy film obtained by electroless plating. Consider a case where the wiring protective film (lid material) 9 is selectively formed to protect the wiring 8.

The process of selectively forming such a wiring protective film (covering material) 9 made of a Co—WP alloy film on the surface of the wiring 8 by general electroless plating will be described first. The substrate W such as a semiconductor wafer is immersed in dilute sulfuric acid at room temperature for about 1 minute to remove CMP residues such as copper remaining on the surface of the insulating film 2. Then, after cleaning the surface of the substrate W with a cleaning solution such as pure water, the substrate W is immersed in, for example, a PdCl ₂ / HCl mixed solution at room temperature for about 1 minute, whereby Pd as a catalyst is formed on the surface of the wiring 8. The exposed surface of the wiring 8 is activated by adhering. Next, after cleaning (rinsing) the surface of the substrate W with pure water or the like, for example, the substrate W is immersed in a Co—WP plating solution having a liquid temperature of 80 ° C. for about 120 seconds to activate the wiring. The surface of 8 is subjected to selective electroless plating, and then the surface of the substrate W is cleaned with a cleaning liquid such as pure water. Thus, the wiring protection film 9 made of a Co—WP alloy film is selectively formed on the exposed surface of the wiring 8 to protect the wiring 8.

  However, the wiring protective film 9 which is selectively formed on the exposed surface of the wiring 8 by electroless plating or the like and protects the wiring 8 is generally made of an alloy film such as a Co alloy or a Ni alloy. For example, a complete barrier property such as a silicon nitride film may not be expected against thermal diffusion of the wiring 8.

Moreover, the exposed surface of the insulating film 2 after the CMP treatment may remain with a residue made of metal, organic matter, etc., and during the catalyst treatment or plating treatment, a reaction occurs with this residue as a nucleus, There is a possibility that the insulating property of the insulating film 2 may be hindered.
Furthermore, since the plating solution is generally alkaline, the insulating film 2 may be altered during the processing, which may deteriorate the adhesion with the insulating film to be laminated.

  The present invention has been made in view of the above circumstances, and enables the wiring to be protected by selectively covering the exposed surface of the wiring with a wiring protective film having an improved barrier property against the wiring. It is an object of the present invention to provide a substrate processing method and a substrate processing apparatus capable of ensuring insulation and film quality.

  In the invention according to claim 1, when the protective film is selectively formed on the exposed surface of the wiring formed on the surface of the substrate to protect the wiring, pretreatment is performed on the surface of the substrate to be plated, Electroless plating is performed on the pretreated surface to be plated to selectively form the wiring protective film, the substrate after the electroless plating is cleaned and dried, and the substrate surface after the drying is applied. A substrate processing method is characterized by performing plasma processing.

In this way, plasma treatment was performed on the protective film on the substrate surface after drying, and a part of the surface side region of the protective film was modified to selectively form the exposed surface of the wiring by electroless plating. The barrier property against the diffusion of the wiring metal of the protective film can be improved. In addition, when forming an insulating film (interlayer insulating film) such as SiO ₂ or SiOC on the surface of the substrate whose wiring is protected by this protective film to form a multilayer wiring, it is formed on the protective film. In addition to improving adhesion to the insulating film, it is possible to physically remove residues such as plating grains and metal components remaining on the surface of the insulating film, thereby improving leakage resistance between wirings. Further, when the insulating film is altered by the plating process, it can be modified.

  Note that plasma processing is usually performed in a reduced pressure atmosphere, which complicates the apparatus, but by performing it in a normal pressure atmosphere, the apparatus can be simplified and the processing time can be shortened. Is possible.

  According to the second aspect of the present invention, when the protective film is selectively formed on the exposed surface of the wiring formed on the surface of the substrate, the surface of the substrate to be plated is subjected to a plasma treatment before the pretreatment, An electroless plating process is performed on the surface of the substrate to be plated to selectively form the protective film, the substrate after the electroless plating process is cleaned and dried, and the substrate surface after the drying is applied A substrate processing method is characterized by performing plasma processing.

In this way, by performing plasma treatment on the surface of the substrate in advance, it is possible to remove metal components on the insulating film after CMP treatment, organic component residues, and metal natural oxide films on the wiring portion. After forming the protective film, plasma treatment is performed again to modify a part of the surface side region of the protective film, whereby the barrier property of the protective film against the diffusion of the wiring metal can be improved. In addition, when an insulating film (interlayer insulating film) such as SiO ₂ or SiOC is formed on the surface of the substrate where the wiring is protected by the protective film, a protective film and an insulating film formed thereon are formed. In addition, it is possible to improve the inter-wiring leakage resistance by physically removing the residue such as plating grains and metal components remaining on the surface of the insulating film. Further, when the insulating film is altered by the plating process, the portion can be modified.

A third aspect of the present invention is the substrate processing method according to the first or second aspect, wherein the pretreatment includes a cleaning process for cleaning the substrate surface.
In general, the results of electroless plating greatly depend on the state of the substrate. Depending on the conditions of the previous process, the surface of the substrate varies greatly, such as an oxide film formed on the wiring film, a metal component remaining on the interlayer insulating film, or a strong anticorrosive agent adsorbed. For this reason, it is possible to perform reproducible plating by performing an appropriate cleaning process as the pre-plating process to clean the entire substrate surface.

  According to a fourth aspect of the present invention, the substrate surface is cleaned by adding a chelating agent to an inorganic acid having a pH of 2 or less, an organic acid having a chelating ability of pH 5 or less, and an inorganic acid having a pH of 5 or less. The substrate surface is brought into contact with a chemical solution composed of an alkaline solution capable of removing the anticorrosive agent of the wiring, the anticorrosive agent of the wiring, or an alkaline solution of amino acids, and then the cleaned substrate surface is rinsed with a rinse solution. The substrate processing method according to claim 1, wherein:

  Examples of the inorganic acid having a pH of 2 or less include hydrofluoric acid, sulfuric acid, and hydrochloric acid. Examples of the organic acid having a chelating ability having a pH of 5 or less include formic acid, acetic acid, succinic acid, tartaric acid, citric acid, maleic acid, and salicylic acid. Examples of the chelating agent added to an inorganic acid having a pH of 5 or less include halides, carboxylic acids, dicarboxylic acids, oxycarboxylic acids, and water-soluble salts thereof. By performing a cleaning process using these, the CMP residue made of copper, etc. remaining on the insulating film and the oxide on the surface of the substrate to be plated are removed, thereby improving the selectivity of plating and adhesion to the substrate. Can do. Further, the anticorrosive agent generally used in the CMP process is usually an inhibitor of the deposition of the plating film, but an alkaline solution having the ability to remove the anticorrosive agent attached to the wiring, for example, tetramethylammonium hydroxide (TMAH) is used. By using it, such an anticorrosive can be effectively removed. The same effect as that of the acids can be realized with an alkaline solution of amino acids such as glycine, cysteine, and methionine.

The invention according to claim 5 is characterized in that the pretreatment includes an activation treatment for activating the substrate surface to be plated by applying a catalyst to the substrate surface to be plated on the cleaned substrate. The substrate processing method according to claim 1.
By applying a catalyst to the wiring portion of the surface to be plated and activating it, electroless plating with improved selectivity can be performed with good reproducibility.

In the invention according to claim 6, the activation treatment of the surface of the substrate to be plated is applied to a chemical solution containing Pd, Ag, Ni, Co, Pt or Au, or a chemical solution containing alkylamine borane or NaBH ₄ The substrate processing method according to claim 6, wherein the substrate surface after the activation treatment is rinsed with a rinse solution.

  Although there are various substances as the catalyst metal, it is preferable to use Pd (palladium) from the viewpoint of reaction rate and ease of control. As a method of applying the catalyst, there are a case where the entire substrate is immersed in the catalyst solution and a case where the catalyst solution is sprayed toward the substrate surface by spraying or the like, depending on the composition of the plating film, the required film thickness, etc. You can choose. In general, when forming a thin film, the spray method is superior in terms of reproducibility. As in the case of the cleaning process, if the catalyst solution remains on the substrate surface, there is a possibility that the wiring material or the like may be corroded or the plating process may be adversely affected. It is desirable to shorten as much as possible.

A seventh aspect of the present invention is the substrate processing method according to any one of the first to sixth aspects, wherein the plasma processing is performed in an atmospheric pressure atmosphere.
As described above, by performing the plasma treatment under a normal pressure atmosphere, it is easy to switch between the wet treatment and the dry treatment (plasma treatment), and it is easy to perform the continuous treatment. In addition, by using remote plasma processing that extrudes the plasma generated in the parallel plate out of the system by the flow of gas, processing can be performed without applying a bias voltage to the substrate, so that damage to the substrate is reduced under normal pressure reduction. Compared to plasma processing of This remote plasma treatment can be performed by using, for example, model AP-T manufactured by Sekisui Chemical Co., Ltd.

According to an eighth aspect of the present invention, the plasma treatment is performed using O ₂ , Ar, He, H ₂ , N ₂ , NH ₃ , SO ₂ , SO ₃ , CF ₄ , C ₂ F ₆ , CF ₃ , CFCF ₂ , The substrate processing method according to claim 1, wherein the substrate processing method is performed in an atmosphere including at least one of the CCIFs ₃ .
By using various gas species in this way, the purpose of processing can be changed, and the result can be prevented from changing depending on the surface of the substrate.

For example, O ₂ gas is used to oxidize the substrate surface to make it hydrophilic, and if physical etching is desired, an inert gas Ar or N ₂ is used, and if the metal surface is reduced, H ₂ / A mixed gas of N ₂ or NH ₃ / N ₂ is used. When a fluorocarbon gas such as CF ₄ is reacted on an oxygen-containing compound, the hydrophilization is promoted, and a water-repellent surface can be obtained by adding fluorine to the surface. Further, it is widely known that the surface of a mixed gas plasma of NH ₃ / N ₂ can be nitrided.

The invention according to claim 9 is characterized in that a film thickness of 1/100 or more and 1/2 or less of a film formed on the substrate surface is modified by the plasma treatment. The substrate processing method according to any one of the above.
Thereby, a protective film can be made into a 2 layer structure, and both adhesiveness with a wiring metal and adhesiveness with an insulating film can be improved. Further, the barrier property against the diffusion of the wiring metal can be improved by modifying the protective film.

The invention described in claim 10 is characterized in that the plasma processing has a plurality of processing steps for changing any of gas type, flow rate, and voltage in the processing. The substrate processing method according to any one of the above.
As a result, a plurality of process conditions can be changed to change the processing target and the reforming conditions.

The invention according to claim 11 is the substrate processing method according to claim 1, wherein the protective film formed by electroless plating is a Co or Ni alloy film containing P or B.
The Co or Ni alloy film preferably contains a refractory metal such as W, Mo, or Re. Thus, by introducing a refractory metal such as W, Mo, or Re into the alloy, A stable plating film can be obtained.

  The invention according to claim 12 is a substrate processing apparatus for selectively forming a wiring protective film on an exposed surface of a wiring formed on a surface of a substrate, the preprocessing chamber for performing a preprocessing on the substrate surface, An electroless plating chamber for selectively forming the wiring protective film by performing electroless plating on the surface of the substrate to be plated of the pretreated substrate; and a post-processing chamber for cleaning and drying the substrate after the electroless plating; A substrate processing apparatus comprising a plasma processing chamber for performing plasma processing on the substrate surface after drying.

  As a result, the entire process becomes compact compared to the case where each processing step is performed by a separate device (processing unit), and a large installation space is not required, and the initial cost and running cost of the device can be reduced, and the processing is short. In time, a substrate with a modified surface can be formed.

According to a thirteenth aspect of the present invention, the pretreatment chamber treats the substrate surface with a chemical solution, removes the chemical solution from the substrate surface, imparts a catalyst to the substrate surface, and applies the catalyst. 13. The substrate processing apparatus according to claim 12, further comprising at least one of a second pretreatment unit that removes the used chemical from the substrate surface.
Although the surface state of the substrate put into the processing apparatus depends on the previous process, the surface cleaning and initialization by the appropriate chemical treatment in the first pretreatment unit and the activity by applying the catalyst in the second pretreatment unit By performing at least one of the crystallization treatments, a plating treatment independent of the previous step can be performed.

In the invention described in claim 14, the electroless plating chamber includes a plating tank, a plating solution circulation system, and a plating solution storage tank, and the plating solution circulation system has flow rates that can be individually set during plating standby and plating treatment. The plating solution can be circulated between the plating tank and the plating solution storage tank, the circulation flow rate of the plating solution during plating standby is 2 to 20 L / min, and the circulation flow rate of the plating solution during plating treatment is 0 to 0. The substrate processing apparatus according to claim 12, wherein the substrate processing apparatus is 10 L / min.
This ensures a large circulating flow rate of the plating solution during plating standby, keeps the temperature of the plating bath in the electroless plating unit constant, and reduces the circulating flow rate of the plating solution during plating to make it more uniform. A wiring protective film (plating film) having a sufficient thickness can be formed.

A fifteenth aspect of the invention is the substrate processing apparatus according to any one of the twelfth to fourteenth aspects, wherein the drying chamber is made of a spin dryer.
Thereby, since a board | substrate can be dried rapidly, productivity as an apparatus can be improved. For example, when a dry air unit is provided, the substrate can be thoroughly dried, and problems such as oxidation of the wiring portion due to adsorbed moisture and generation of water marks due to mistback can be avoided.

According to a sixteenth aspect of the present invention, the plasma processing chamber includes a plasma processing chamber for performing plasma processing, and a transfer unit for blocking an atmosphere in the plasma processing unit and the apparatus. The substrate processing apparatus according to any one of 1 to 15.
The invention according to claim 17 is characterized in that the plasma processing unit has a heater for controlling temperature, and the transfer unit has a cool plate for cooling the substrate. This is a substrate processing apparatus. Thereby, the reactivity of the substrate surface at the time of plasma processing can be controlled, and by cooling with a cool plate, it is possible to suppress reaction with the atmosphere when the substrate is released into the atmosphere.

  According to the present invention, plasma treatment is performed on the protective film on the surface of the substrate after drying, and a part of the surface side region of the protective film is modified so that the exposed surface of the wiring is selectively deposited by electroless plating. The barrier property of the protective film formed on the wiring can be improved. In addition, the insulating film portion can be modified, and the adhesion and leakage resistance between wirings can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 2 is a plan layout view of the substrate processing apparatus according to the embodiment of the present invention. As shown in the figure, in this substrate processing apparatus, a substrate cassette 10 containing a substrate W (see FIG. 4, the same applies hereinafter) in which wiring 8 made of copper or the like is formed in a wiring groove 4 formed on the surface is mounted. A loading / unloading unit 12 is provided. A first pretreatment unit (pretreatment chamber) 18 that cleans the surface of the substrate W at the position along one long side of the rectangular housing 16 provided with the exhaust system, that is, the surface of the substrate W, is provided. Similarly, electroless plating is performed on the surface (surface to be processed) of the second pretreatment unit (pretreatment chamber) 20 and the substrate W to be activated by applying a catalyst to the exposed surface of the wiring 8 after cleaning. A plating chamber 22 is arranged in series.

  Further, the selectivity of the wiring protective film (alloy film) 9 (see FIG. 4, the same applies hereinafter) formed on the surface of the wiring 8 by electroless plating at a position along the other long side of the housing 16 is improved. A cleaning chamber 26 for cleaning the substrate W for cleaning, a post-processing chamber 28 for cleaning and drying the plated substrate W, and a plasma processing chamber 30 for performing plasma processing on the wiring protection film 9 on the dried substrate surface. They are arranged in series. Further, a transport robot 34 that can run along the rails 32 in parallel with the long side of the housing 16 and transfers substrates between the chambers and the substrate cassette 10 mounted in the load / unload unit 12 is provided. , Are arranged at positions sandwiched between the linearly arranged chambers.

Next, a series of substrate processing by this substrate processing apparatus will be described with further reference to FIGS. In this example, as shown in FIG. 4A, a wiring groove 4 is formed inside an insulating film 2 such as an oxide film made of SiO ₂ or SiOC deposited on the surface of a substrate W such as a semiconductor wafer. After the barrier layer 5 made of TaN or the like and the Cu seed layer 6 are formed on the surface by PVD, copper plating is performed, and a copper film 7 is formed on the surface of the substrate W to be embedded in the wiring groove 4. Next, as shown in FIG. 4B, the surface of the substrate W is flattened by CMP (chemical mechanical polishing), thereby forming the wiring 8 made of the copper film 7 inside the insulating film 2. Keep it. Then, on the surface of the wiring (copper film) 8, a wiring protective film (cover material) 9 made of, for example, electroless plating and made of a Co—WP alloy film is selectively formed to protect the wiring 8. The case will be described.

First, as shown in FIG. 4B, a substrate cassette in which wiring 8 is formed on the surface and dried, is stored in the load / unload unit 12 with the surface of the substrate W facing upward (face up). From 10, one substrate W is taken out by the transfer robot 34 and transferred to the first pretreatment unit (pretreatment chamber) 18. In the first pretreatment unit 18, the substrate W is held face down, and the surface is subjected to a cleaning treatment (chemical solution washing) as a pretreatment for plating. That is, for example, at a liquid temperature of 25 ° C., a chemical solution such as diluted oxalic acid (COOH) ₂ is sprayed toward the surface of the substrate W, and the CMP residue such as copper remaining on the surface of the insulating film 2 and the wiring film The oxides and the like are removed, and then the cleaning liquid remaining on the surface of the substrate W is rinsed (cleaned) with a rinse liquid such as pure water.

  As the chemical solution used here, inorganic acids such as hydrofluoric acid, sulfuric acid and hydrochloric acid having a pH of 2 or less, and organic compounds having a chelating ability of pH 5 or less such as formic acid, acetic acid, succinic acid, tartaric acid, citric acid, maleic acid and salicylic acid are used. Examples thereof include acids, inorganic acids having a pH of 5 or less, to which chelating agents such as halides, carboxylic acids, dicarboxylic acids, oxycarboxylic acids and water-soluble salts thereof are added. By performing a cleaning process using these chemicals, the CMP residue made of copper or the like remaining on the insulating film and the oxide on the surface of the plating base are removed, and the selectivity of plating and the adhesion to the base are improved. be able to. Moreover, the anticorrosive agent generally used in the CMP process is usually an inhibitor of the deposition of the plating film, but an alkaline chemical solution having the ability to remove the anticorrosive agent adhering to the wiring, for example, tetramethylammonium hydroxide (TMAH) By using it, such an anticorrosive can be effectively removed. The same effect as that of the acids can be realized with an alkaline solution of amino acids such as glycine, cysteine, and methionine.

  Also, by rinsing (cleaning) the surface of the substrate W with a rinsing liquid after cleaning, the chemical used for cleaning remains on the surface of the substrate W, which may hinder the next activation process. As the rinsing liquid that can be prevented, ultrapure water is generally used. However, depending on the material configuration of the surface of the substrate to be plated, even if ultrapure water is used, the wiring material corrodes due to local battery action or the like. Sometimes. In such a case, the rinsing liquid does not contain impurities such as hydrogen gas-dissolved water obtained by dissolving hydrogen gas in ultrapure water, or electrolytic cathode water obtained by diaphragm-type electrolysis of ultrapure water. It is desirable to use water with high reducing power. Further, since the chemical used for the cleaning process may have some corrosiveness to the wiring material or the like, it is preferable that the time between the cleaning process and the rinsing process is as short as possible.

  In this example, the cleaning process (pre-plating process) of the surface of the wiring 8 is performed using a chemical solution, but the cleaning process of the surface of the wiring 8 is performed on the substrate by plasma processing. You may make it carry out. By such a physical process, a uniform process can be performed on a substrate in which the wiring 8 and the insulating film 2 are mixed.

Next, the substrate W after the cleaning process and the rinsing process is transported to the second pretreatment unit (pretreatment chamber) 20 by the transport robot 34, where the substrate W is held face down to activate the surface. (Catalyst application) treatment is performed. That is, for example, at a liquid temperature of 25 ° C., a mixed solution such as PdCl ₂ / HCl is sprayed toward the surface of the substrate W, whereby Pd as a catalyst is applied to the surface of the wiring 8 by displacement plating. Pd nuclei as catalyst nuclei (seed) are formed on the surface of the wiring 8 to activate the exposed surface of the surface wiring of the wiring 8. Further, using Cu as a catalyst, the plating reaction can be started and brought into contact with a chemical solution containing alkylamine borane or NaBH ₄ to be activated. Thereafter, the catalyst solution remaining on the surface of the substrate W is rinsed (washed) with a rinse solution such as pure water.

  Thus, by providing a catalyst on the surface of the substrate W, the selectivity of electroless plating can be enhanced. Here, as the catalyst metal, Ag, Ni, Co, Pt, Au, or the like is used in addition to Pd in this example. However, it is preferable to use Pd from the viewpoint of reaction rate and ease of control. . As a method of applying the catalyst, there are a case where the entire substrate is immersed in the catalyst solution and a case where the catalyst solution is sprayed toward the substrate surface by spraying or the like, depending on the composition of the plating film, the required film thickness, etc. You can choose. In general, when forming a thin film, the spray method is superior in terms of reproducibility.

  Further, in order to improve selectivity, it is necessary to remove the residual Pd on the insulating film 2 and the wiring 8, and pure water rinsing is generally used. As in the case of the cleaning process, if the catalyst solution remains on the substrate surface, there is a possibility that the wiring material or the like may be corroded or the plating process may be adversely affected. It is desirable to shorten as much as possible. As the rinsing liquid, it is possible to use pure water, hydrogen gas-dissolved water, or electrolytic cathode water as in the case of the cleaning treatment, but in order to familiarize the substrate prior to the next plating step. It is also possible to use an aqueous solution of components constituting the electroless plating solution.

  This example shows an example in which the activation treatment by Pd displacement plating on the surface of the wiring 8 is performed using a chemical solution (catalyst solution). However, this activation treatment is performed by light irradiation, CVD method. Or you may make it carry out by PVD method.

  Then, the substrate W that has been provided with the catalyst and rinsed is transported to the electroless plating chamber 22 by the transport robot 34, where the substrate W is held face down, and the surface is subjected to electroless plating. That is, for example, the substrate W is immersed in a Co—WP plating solution having a liquid temperature of 80 ° C. for about 120 seconds, for example, and the surface of the activated wiring 8 is selectively electroless plated (electroless Co). -W-P lid plating) is performed to selectively form a wiring protective film (lid material) 9 as shown in FIG. The composition of this plating solution is, for example, as follows.

・ CoSO ₄ · 7H ₂ O: 14 g / L
_{· Na 3 C 6 H 5 O} 7 · 2H 2 O: 70g / L
・ H ₃ BO ₃ : 40 g / L
・ Na ₂ WO ₄ · 2H ₂ O: 12 g / L
_{· NaH 2 PO 2 · H 2} O: 21g / L
・ PH: 9.2

  Here, it is preferable to use a plating solution having a pH of 7 to 10, an alkali metal element, and no ammonium ion. In general, in electroless plating, the plating solution is heated to control the reaction. However, if ammonium ions are included in the heated plating solution, ammonia tends to volatilize, so the plating solution composition must be maintained stably. It becomes difficult. For this reason, it becomes difficult to maintain reproducibility such as the plating rate and the plating film composition over a long period of time. Such an adverse effect can be prevented by using, for example, an alkali metal salt as a constituent of the plating solution instead of an ammonium salt so that ammonium ions are not contained in the plating solution.

And after raising the board | substrate W from a plating solution, the stop liquid which consists of neutral liquid with pH 6-7.5 is made to contact the surface of the board | substrate W, and an electroless-plating process is stopped. Thereby, immediately after pulling up the substrate W from the plating solution, the plating reaction can be stopped quickly, and the occurrence of uneven plating in the plating film can be prevented. This processing time is preferably 1 to 5 seconds, for example. Examples of the stop liquid include pure water, hydrogen gas-dissolved water, or electrolytic cathode water.
Thereafter, the plating solution remaining on the surface of the substrate is rinsed (washed) with a rinse solution such as pure water. Thus, the wiring protection film 9 made of a Co—WP alloy film is selectively formed on the surface of the wiring 8 to protect the wiring 8.

  Next, the substrate W after the electroless plating treatment is transported to the cleaning chamber 26 by the transport robot 34, where the selectivity of the wiring protective film (plating film) 9 formed on the surface of the substrate W is improved. A substrate cleaning process is performed to increase the yield. That is, a chemical solution containing one or more of a surfactant, an organic alkali, and a chelating agent is applied to the surface of the substrate W while applying a physical force such as roll scrub cleaning or pencil cleaning to the surface of the substrate W. In this way, plating residues such as metal fine particles on the insulating film 2 are completely removed, and the plating selectivity is improved. By using these chemical solutions, the selectivity of electroless plating can be improved more efficiently. The surfactant is preferably nonionic, the organic alkali is preferably quaternary ammonium or amines, and the chelating agent is preferably ethylenediamine.

  When the chemical solution is used in this way, the chemical solution remaining on the surface of the substrate W is rinsed (washed) with a rinse solution such as pure water. Examples of the rinse liquid include pure water, hydrogen gas-dissolved water, and electrolytic cathode water. Similar to the above, the wiring material may corrode due to the local battery action etc. depending on the material composition of the surface, but in such a case, rinsing with ultrapure water with reducing properties, Evil can be avoided.

In addition to the above-described cleaning by physical force such as roll scrub cleaning or pencil cleaning, the insulating film may be combined in any combination by cleaning with a complexing agent and further by uniform etching back with an etching solution. The residue above may be completely removed.
Then, the substrate W after the cleaning process is transferred to the post-processing chamber 28 by the transfer robot 34, where a rinsing process is performed if necessary, and then the substrate W is rotated at a high speed and spin-dried.

  When performing the drying process (spin drying) for making the substrate W dry, it is preferable to control the humidity of the atmosphere around the substrate using dry air or a dry inert gas. When the substrate is dried in a normal atmosphere, the moisture on the substrate is scattered in the atmosphere and the humidity is increased, and a large amount of moisture is adsorbed on the substrate surface even though it has been dried. There is a possibility of causing a new problem such as oxidation of the wiring portion by the adsorbed moisture. In addition, problems such as the generation of water marks due to mistback in a spin dryer are also assumed. For this reason, such an adverse effect can be avoided by controlling the atmospheric humidity during drying using dry air or dry nitrogen.

The substrate W after the spin drying is transferred to the plasma processing chamber 30 by the transfer robot 34, and here, the wiring protection film 9 of the substrate W is subjected to plasma processing. For example, nitrogen (N.) radicalized by glow discharge is infiltrated into the inside of the wiring protective film 9 from the surface of the wiring protective film 9 by using N ₂ or NH ₃ , and as shown in FIG. As described above, the modified film 9 a is formed on the surface of the wiring protective film 9.

In this plasma treatment, for example, the substrate W is placed in a furnace (processing chamber) containing N ₂ whose pressure is reduced to 1 to 10 Torr, for example, an NH ₃ atmosphere or an N ₂ atmosphere, and the substrate W is a cathode and a furnace body. Can be performed by applying a voltage of about 500 V between the two electrodes and causing N · radicalized by glow discharge to collide with the cathode substrate at high speed.

  In addition, plasma processing is normally performed in a reduced pressure atmosphere. Therefore, vacuum equipment is required, which complicates the apparatus, but vacuum equipment is not required by performing plasma processing in a normal pressure atmosphere. None, thereby a more simplified device has been developed. For example, when AP-T (model) manufactured by Sekisui Chemical Co., Ltd. is used, the substrate can be processed with a remote plasma method, since it is not necessary to apply a bias voltage to the substrate and damage to the substrate is reduced.

  In this way, plasma treatment is performed on the wiring protective film 9 selectively formed on the exposed surface of the wiring 8 by electroless plating, and a modified film 9 a is formed in a part of the surface side region of the wiring protective film 9. Thereby, the barrier property with respect to the wiring 8 of the wiring protective film 9 can be improved. That is, for example, when the exposed surface of the wiring 8 made of copper is selectively covered with the wiring protective film 9 made of an alloy film such as Ni alloy or Co alloy (Co-WP in this example), the wiring 8 is protected. The alloy film generally has a heat transfer property, and a complete barrier property such as a silicon nitride film may not be desired for the thermal diffusion of the wiring 8, but a part of the surface side region of the wiring protective film 9 By forming the modified film 9a, a complete barrier property like a silicon nitride film can be secured.

In addition, as shown in FIG. 5, the plasma treatment is performed to form the modified film 9 a on the surface of the wiring protective film 9, so that the wiring W is protected by the wiring protective film 9 on the surface of the substrate W. In addition, when an insulating film (protective film) 40 such as SiO ₂ or SiOC is formed to form a multilayer wiring, the adhesion between the wiring protective film 9 and the insulating film 40 formed thereon can be improved. it can. Even when an insulating film (interlayer insulating film) such as SiO ₂ , low-k material, SiOC or SiOF is directly laminated on the surface of the substrate W where the wiring 8 is protected by the wiring protective film 9, the wiring The adhesion between the protective film 9 and these insulating films can be improved.
Furthermore, along with this plasma treatment, dust such as plating grains and metal grains remaining on the surface of the insulating film 2 can be physically removed to improve leakage resistance.

The film thickness t of the modified film 9a is preferably about 1/100 or more and 1/2 or less (t = 1/100 to 1 / 2T) of the film thickness T of the wiring protective film 9. As a result, the barrier property of the wiring protective film 9 with respect to the wiring 8 can be enhanced, and the adhesion with the insulating film 40 formed on the wiring protective film 9 can be enhanced.
Then, the substrate W after the plasma processing is returned to the substrate cassette 10 mounted on the load / unload unit 12 by the transfer robot 34.

  In the above example, copper (Cu) is used as a wiring material, and a wiring protective film 9 made of a Co—WP alloy film is selectively formed on the surface of the wiring 8 made of copper. However, Cu wiring, Ag or Ag alloy may be used as the wiring material, and Co-P, Co-Mo-P, Co-B, Co-WB, Co may be used as the wiring protective film 9. -Mo-B, Ni-P, Ni-WP, Ni-B, Ni-WB, Ni-Mo-P or Ni-Mo-B alloy films may be used.

Next, details of various chambers provided in the substrate processing apparatus shown in FIG. 2 will be described below.
The pre-treatment chamber having the first pre-treatment unit 18 and the second pre-treatment unit 20 employs a two-liquid separation system having the same configuration and preventing mixing of different liquids only in the treatment liquid (chemical solution) used. Therefore, the peripheral portion of the lower surface, which is the processing surface (front surface) of the substrate W transported face down, is sealed, and the substrate W is fixed by pressing the back surface side.

  As shown in FIGS. 6 to 9, the pretreatment chambers 18 and 20 include a fixed frame 52 attached to the upper portion of the frame 50 and a moving frame 54 that moves up and down relative to the fixed frame 52. A processing head 60 having a bottomed cylindrical housing portion 56 and a substrate holder 58 that are opened downward is suspended and supported by the moving frame 54. In other words, the head rotating servo motor 62 is attached to the moving frame 54, and the housing portion 56 of the processing head 60 is connected to the lower end of the output shaft (hollow shaft) 64 that extends below the servo motor 62.

  As shown in FIG. 9, a vertical shaft 68 that rotates integrally with the output shaft 64 is inserted into the output shaft 64 via a spline 66, and a ball joint 70 is attached to the lower end of the vertical shaft 68. The substrate holder 58 of the processing head 60 is connected through the via. The substrate holder 58 is located inside the housing portion 56. The upper end of the vertical shaft 68 is connected to a fixed ring elevating cylinder 74 fixed to the moving frame 54 via a bearing 72 and a bracket. Thus, the vertical shaft 68 moves up and down independently of the output shaft 64 in accordance with the operation of the lifting cylinder 74.

  The fixed frame 52 is attached with a linear guide 76 that extends in the vertical direction and serves as a guide for raising and lowering the moving frame 54, and the moving frame 54 is moved in accordance with the operation of the head elevating cylinder (not shown). 76 is used as a guide.

  A substrate insertion window 56 a for inserting the substrate W is provided in the peripheral wall of the housing portion 56 of the processing head 60. Further, as shown in FIGS. 10 and 11, a peripheral portion is sandwiched between a main frame 80 made of PEEK and a guide frame 82 made of polyethylene, for example, at the lower portion of the housing portion 56 of the processing head 60. A seal ring 84a is disposed. This seal ring 84a is in contact with the peripheral edge of the lower surface of the substrate W to seal it.

  On the other hand, a substrate fixing ring 86 is fixed to the peripheral edge of the lower surface of the substrate holder 58, and a cylindrical pusher 90 is connected to the substrate via the elastic force of a spring 88 disposed inside the substrate fixing ring 86 of the substrate holder 58. It protrudes downward from the lower surface of the fixing ring 86. Further, a bendable cylindrical bellows plate 92 made of, for example, Teflon (registered trademark) is hermetically sealed between the upper surface of the substrate holder 58 and the upper wall portion of the housing portion 56. Yes.

  Accordingly, the substrate W is inserted into the housing portion 56 from the substrate insertion window 56a with the substrate holder 58 raised. Then, the substrate W is guided by a tapered surface 82a provided on the inner peripheral surface of the guide frame 82, positioned, and placed at a predetermined position on the upper surface of the seal ring 84a. In this state, the substrate holder 58 is lowered, and the pusher 90 of the substrate fixing ring 86 is brought into contact with the upper surface of the substrate W. Then, by further lowering the substrate holder 58, the substrate W is pressed downward by the elastic force of the spring 88, and is thereby pressed against the peripheral portion of the surface (lower surface) of the substrate W by the seal ring 84a, thereby sealing it. However, the substrate W is sandwiched and held between the housing portion 56 and the substrate holder 58.

  When the head rotating servomotor 62 is driven in a state where the substrate W is held by the substrate holder 58 as described above, the output shaft 64 and the vertical shaft 68 inserted into the output shaft 64 are connected to the spline 66. Accordingly, the housing portion 56 and the substrate holder 58 are also rotated integrally.

  A processing tank 100 having an outer tank 100a and an inner tank 100b, which is located below the processing head 60 and opens upward having an inner diameter slightly larger than the outer diameter of the processing head 60, is provided. A pair of legs 104 attached to the lid 102 are rotatably supported on the outer periphery of the processing bath 100. Further, a crank 106 is integrally connected to the leg 104, and a free end of the crank 106 is rotatably connected to a rod 110 of the lid moving cylinder 108. Accordingly, the lid 102 is configured to move between a processing position that covers the upper end opening of the processing tank 100 and a side retracted position in accordance with the operation of the lid moving cylinder 108. . The surface (upper surface) of the lid 102 is provided with a nozzle plate 112 having a plurality of injection nozzles 112a for injecting electrolytic ion water having reducing power, for example, outward (upward) as described below. Yes.

  Furthermore, as shown in FIG. 12, a plurality of injection nozzles 124a for injecting the chemical liquid supplied from the chemical liquid tank 120 in accordance with the driving of the chemical liquid pump 122 upward are provided in the inner tank 100b of the processing tank 100. The nozzle plate 124 having the nozzles 124a is arranged in a state where the spray nozzles 124a are more evenly distributed over the entire cross section of the inner tank 100b. A drain pipe 126 for discharging a chemical solution (drainage) to the outside is connected to the bottom surface of the inner tank 100b. A three-way valve 128 is provided in the middle of the drain pipe 126, and this chemical solution (drainage) is supplied to the chemical solution as needed via a return pipe 130 connected to one outlet port of the three-way valve 128. It can be returned to the tank 120 and reused. Furthermore, in this example, the nozzle plate 112 provided on the surface (upper surface) of the lid 102 is connected to a rinse liquid supply source 132 that supplies a rinse liquid such as pure water. A drain pipe 127 is also connected to the bottom surface of the outer tub 100a.

  Thereby, the processing head 60 holding the substrate is lowered to cover the upper end opening of the processing tank 100 so as to be closed by the processing head 60, and in this state, the nozzle plate disposed inside the inner tank 100 b of the processing tank 100. By spraying the chemical liquid from the spray nozzle 124a toward the substrate W, the chemical liquid is uniformly sprayed over the entire lower surface (processing surface) of the substrate W, and the chemical liquid is prevented from scattering to the outside. Can be discharged from the drain pipe 126 to the outside. Furthermore, the processing head 60 is raised, and the nozzle plate 112 disposed on the upper surface of the lid body 102 is directed toward the substrate W held by the processing head 60 in a state where the upper end opening of the processing tank 100 is closed by the lid body 102. By rinsing the rinsing liquid from the spray nozzle 112a, the chemical liquid remaining on the substrate surface is rinsed (cleaning process), and this rinsing liquid passes between the outer tank 100a and the inner tank 100b and passes through the drain pipe 127. Therefore, it is prevented from flowing into the inner tank 100b, so that the rinse liquid is not mixed with the chemical liquid.

  According to the pretreatment chambers 18 and 20, as shown in FIG. 6, with the processing head 60 raised, the substrate W is inserted and held therein, and then, as shown in FIG. The processing head 60 is lowered and positioned at a position that covers the upper end opening of the processing bath 100. Then, by rotating the processing head 60 and rotating the substrate W held by the processing head 60, the chemical liquid is sprayed toward the substrate W from the spray nozzle 124 a of the nozzle plate 124 disposed inside the processing tank 100. The chemical liquid is sprayed uniformly over the entire surface of the substrate W. Further, the processing head 60 is raised and stopped at a predetermined position, and the lid 102 that has been in the retracted position is moved to a position that covers the upper end opening of the processing bath 100 as shown in FIG. In this state, the rinsing liquid is ejected from the ejection nozzles 112 a of the nozzle plate 112 disposed on the upper surface of the lid 102 toward the substrate W held and rotated by the processing head 60. Thereby, the process by the chemical | medical solution of the board | substrate W and the rinse process by a rinse liquid can be performed, keeping two liquids not mixing.

  The electroless plating chamber 22 is shown in FIGS. The electroless plating chamber 22 includes a plating tank 200 (see FIG. 19) and a substrate head 204 that is disposed above the plating tank 200 and holds the substrate W in a detachable manner.

  As shown in detail in FIG. 13, the substrate head 204 includes a housing portion 230 and a head portion 232, and the head portion 232 mainly includes a suction head 234 and a substrate receiver 236 that surrounds the suction head 234. It is configured. The housing portion 230 houses a substrate rotation motor 238 and a substrate receiving drive cylinder 240. The upper end of the output shaft (hollow shaft) 242 of the substrate rotation motor 238 is at the rotary joint 244, and the lower end is at the lower end. The rods of the substrate receiving drive cylinder 240 are connected to the suction head 234 of the head unit 232, respectively, and are connected to the substrate receiver 236 of the head unit 232. Further, a stopper 246 that mechanically restricts the rise of the substrate receiver 236 is provided inside the housing portion 230.

  Here, a similar spline structure is employed between the suction head 234 and the substrate receiver 236, and the substrate receiver 236 moves up and down relatively with respect to the suction head 234 in accordance with the operation of the substrate receiver driving cylinder 240. When the output shaft 242 is rotated by driving the substrate rotating motor 238, the suction head 234 and the substrate receiver 236 are integrally rotated with the rotation of the output shaft 242.

As shown in detail in FIG. 14 to FIG. 16, a suction ring 250 that sucks and holds the substrate W with the lower surface serving as a sealing surface is attached to the suction head 234 via a pressing ring 251. A concave portion 250 a provided continuously in the circumferential direction on the lower surface of the nozzle and a vacuum line 252 extending in the suction head 234 communicate with each other through a communication hole 250 b provided in the suction ring 250. Thus, the substrate W is sucked and held by evacuating the concave portion 250a. Thus, by holding the substrate W by evacuating it with a small width (in the radial direction), By minimizing the influence (deflection, etc.) on the substrate W due to the vacuum, and immersing the adsorption ring 250 in the plating solution (processing solution), not only the surface (lower surface) but also the edge of the substrate W It becomes possible to immerse in the plating solution. The substrate W is released by supplying N ₂ to the vacuum line 252.

  On the other hand, the substrate receiver 236 is formed in a bottomed cylindrical shape that opens downward, a peripheral wall is provided with a substrate insertion window 236a for inserting the substrate W therein, and a disc protruding inward at the lower end. A claw portion 254 is provided. Further, a projection piece 256 having a taper surface 256 a serving as a guide for the substrate W on the inner peripheral surface is provided on the upper portion of the claw portion 254.

  Thereby, as shown in FIG. 14, the substrate W is inserted into the substrate receiver 236 from the substrate insertion window 236a with the substrate receiver 236 lowered. Then, the substrate W is guided by the tapered surface 256 a of the protrusion piece 256, positioned, and placed and held at a predetermined position on the upper surface of the claw portion 254. In this state, the substrate receiver 236 is raised, and the upper surface of the substrate W placed and held on the claw portion 254 of the substrate receiver 236 is brought into contact with the suction ring 250 of the suction head 234 as shown in FIG. Next, the concave portion 250 a of the suction ring 250 is evacuated through the vacuum line 252, and the substrate W is sucked and held while the peripheral portion of the upper surface of the substrate W is sealed to the lower surface of the suction ring 250. When performing the plating process, as shown in FIG. 16, the substrate receiver 236 is lowered by several mm, the substrate W is separated from the claw portion 254, and is brought into a state of being sucked and held only by the suction ring 250. Thereby, it can prevent that the peripheral part of the surface (lower surface) of the board | substrate W stops being plated by presence of the nail | claw part 254. FIG.

  FIG. 17 shows details of the plating tank 200. The plating tank 200 is connected to a plating solution supply pipe 308 (see FIG. 19) at the bottom, and a plating solution recovery groove 260 is provided in the peripheral wall portion. Two rectifying plates 262 and 264 that stabilize the flow of the plating solution flowing upward are disposed inside the plating bath 200, and further, the plating solution introduced into the plating bath 200 is provided at the bottom. A temperature measuring device 266 for measuring the liquid temperature is installed. Moreover, the pH is 6-7 in the inside of the plating tank 200 which is located slightly above the liquid surface of the plating solution held in the plating tank 200 on the outer peripheral surface of the peripheral wall of the plating tank 200 and slightly obliquely upward in the diameter direction. 5 is provided with an injection nozzle 268 for injecting a stop liquid composed of a neutral liquid, for example, pure water. Thus, after the plating is finished, the substrate W held by the head portion 232 is pulled up slightly above the liquid surface of the plating solution to temporarily stop, and in this state, pure water (stopping liquid) is directed from the spray nozzle 268 toward the substrate W. The substrate W is immediately cooled by spraying, so that the plating can be prevented from proceeding with the plating solution remaining on the substrate W.

  Further, the upper end opening of the plating tank 200 is closed to prevent unnecessary evaporation of the plating solution from the plating tank 200 when the plating process such as idling is not performed. A plating tank cover 270 is installed so as to be freely opened and closed.

  As shown in FIG. 19, the plating tank 200 extends from the plating solution storage tank 302 at the bottom, and is connected to a plating solution supply pipe 308 having a plating solution supply pump 304 and a three-way valve 306 interposed therebetween. Thus, during the plating process, the plating solution is supplied into the plating tank 200 from the bottom, and the overflowing plating solution is recovered from the plating solution recovery groove 260 to the plating solution storage tank 302, so that the plating solution is recovered. It can be circulated. A plating solution return pipe 312 that returns to the plating solution storage tank 302 is connected to one outlet port of the three-way valve 306. Thus, the plating solution can be circulated even when the plating is on standby, thereby constituting a plating solution circulation system. In this way, by constantly circulating the plating solution in the plating solution storage tank 302 via the plating solution circulation system, the rate of decrease in the concentration of the plating solution is reduced as compared with the case where the plating solution is simply stored, The number of substrates W that can be processed can be increased.

  In particular, in this example, by controlling the plating solution supply pump 304, it is possible to individually set the flow rate of the plating solution that circulates during plating standby and plating processing. That is, the circulation flow rate of the plating solution at the time of plating standby is set to 2 to 20 L / min, for example, and the circulation flow rate of the plating solution at the time of plating treatment is set to 0 to 10 L / min, for example. This ensures a large circulating flow rate of plating solution during plating standby, keeps the temperature of the plating bath in the cell constant, and lowers the circulating flow rate of plating solution during plating to achieve a more uniform film thickness. The wiring protective film (plating film) can be formed.

  A temperature measuring device 266 provided near the bottom of the plating tank 200 measures the temperature of the plating solution introduced into the plating tank 200, and based on this measurement result, the heater 316 and the flow meter 318 described below. To control.

  In other words, in this example, water heated by using a separate heater 316 and passed through the flow meter 318 is used as a heat medium, and the heat exchanger 320 is installed in the plating solution in the plating solution storage tank 302. A heating device 322 for indirectly heating the plating solution, and a stirring pump 324 for circulating and stirring the plating solution in the plating solution storage tank 302. This is because, in the case of plating, the plating solution may be used at a high temperature (about 80 ° C.), and this is to cope with this. According to this method, compared to the in-line heating method, It is possible to prevent unnecessary substances from being mixed into the delicate plating solution.

  FIG. 18 shows the details of the cleaning tank 202 attached to the side of the plating tank 200. A plurality of injection nozzles 280 for injecting a rinse liquid such as pure water upward are attached to the nozzle plate 282 at the bottom of the cleaning tank 202, and the nozzle plate 282 is arranged at the upper end of the nozzle vertical axis 284. It is connected to. Further, the nozzle vertical shaft 284 moves up and down by changing the screwing position of the nozzle position adjusting screw 287 and the nut 288 screwed to the screw 287, whereby the jet nozzle 280 and the jet nozzle 280 are moved. The distance from the substrate W arranged above can be adjusted optimally.

  Further, a cleaning liquid such as pure water is sprayed into the cleaning tank 202 at a position slightly above the diametrical direction, slightly above the spray nozzle 280 on the outer peripheral surface of the peripheral wall of the cleaning tank 202, and the head of the substrate head 204. A head cleaning nozzle 286 for spraying the cleaning liquid on at least a portion in contact with the plating solution of the part 232 is installed.

  In this cleaning tank 202, the substrate W held by the head portion 232 of the substrate head 204 is disposed at a predetermined position in the cleaning tank 202, and a cleaning liquid (rinsing liquid) such as pure water is sprayed from the spray nozzle 280. Then, the substrate W is cleaned (rinsed). At this time, a cleaning liquid such as pure water is simultaneously ejected from the head cleaning nozzle 286, and at least a portion of the head portion 232 of the substrate head 204 that is in contact with the plating solution is By washing with the cleaning solution, it is possible to prevent the deposits from accumulating in the portion immersed in the plating solution.

In the electroless plating chamber 22, the substrate W is adsorbed and held by the head portion 232 of the substrate head 204 at the position where the substrate head 204 is raised, and the plating solution in the plating tank 200 is circulated. Let me.
When the plating process is performed, the plating tank cover 270 of the plating tank 200 is opened, the substrate head 204 is lowered while rotating, and the substrate W held by the head portion 232 is immersed in the plating solution in the plating tank 200.

  Then, after the substrate W is immersed in the plating solution for a predetermined time, the substrate head 204 is raised, the substrate W is pulled up from the plating solution in the plating tank 200, and if necessary, the substrate W is applied to the substrate W as described above. The substrate W is immediately cooled by spraying pure water (stop liquid) from the spray nozzle 268 toward the substrate, and the substrate head 204 is further lifted to lift the substrate W to a position above the plating tank 200 to rotate the substrate head 204. Stop.

  Next, the substrate head 204 is moved to a position directly above the cleaning tank 202 while the substrate W is sucked and held by the head portion 232 of the substrate head 204. Then, while rotating the substrate head 204, the substrate head 204 is lowered to a predetermined position in the cleaning tank 202, and a cleaning liquid (rinsing liquid) such as pure water is sprayed from the spray nozzle 280 to clean (rinse) the substrate W. A cleaning liquid such as pure water is ejected from the cleaning nozzle 286, and at least a portion of the head portion 232 of the substrate head 204 that comes into contact with the plating solution is cleaned with the cleaning liquid.

  After the cleaning of the substrate W is completed, the rotation of the substrate head 204 is stopped, the substrate head 204 is raised, the substrate W is pulled up to a position above the cleaning tank 202, and the substrate head 204 is further transferred to the transfer robot 34. The substrate W is transferred to the transfer robot 34 and transferred to the next process.

  FIG. 20 shows the cleaning chamber 26 and the post-processing chamber 28 in FIG. The cleaning chamber 26 is equipped with a roll brush and the post-processing chamber 28 is equipped with a spin dry.

  FIG. 21 shows the cleaning chamber 26. The cleaning chamber 26 is a chamber in which particles and unnecessary materials on the substrate W are forcibly removed with a roll-shaped brush. The cleaning chamber 26 includes a plurality of rollers 410 that hold the substrate W while sandwiching the outer periphery of the substrate W, and a roller 410. A chemical solution nozzle 412 for supplying a treatment liquid (two lines) to the surface of the held substrate W and a pure water nozzle (not shown) for supplying pure water (one line) to the back surface of the substrate W are provided. Yes.

  As a result, the substrate W is held by the roller 410, the roller drive motor is driven to rotate the roller 410 to rotate the substrate W, and at the same time, a predetermined process is performed on the front and back surfaces of the substrate W from the chemical solution nozzle 412 and the pure water nozzle. The liquid is supplied, and the substrate W is sandwiched and washed from above and below by an upper and lower roll sponge (roll brush) (not shown). The cleaning effect can be increased by rotating the roll sponge alone.

  Further, the cleaning chamber 26 is provided with a sponge (PFR) 419 that rotates while contacting the edge (outer peripheral portion) of the substrate W, and the sponge 419 is applied to the edge of the substrate W to perform scrub cleaning. ing.

  FIG. 22 shows the post-processing chamber 28. The post-processing chamber 28 is a chamber in which chemical cleaning and pure water cleaning are first performed, and then the substrate W after cleaning is completely dried by rotating the spindle, and a clamp mechanism 420 that grips an edge portion of the substrate W is provided. A substrate stage 422 provided, and a substrate attaching / detaching lifting plate 424 for opening and closing the clamp mechanism 420 are provided. The substrate stage 422 is connected to the upper end of a spindle 428 that rotates at a high speed as the spindle rotation motor 426 is driven.

Further, a mega jet nozzle 430 that is located on the upper surface side of the substrate W gripped by the clamp mechanism 420 and that supplies pure water with enhanced cleaning effect by transmitting ultrasonic waves when passing through a special nozzle by an ultrasonic oscillator; A rotatable pencil-type cleaning sponge 432 is attached and arranged on the free end side of the swivel arm 434. Accordingly, the cleaning sponge 432 is supplied to the surface of the substrate W while supplying the pure water from the mega jet nozzle 430 toward the cleaning sponge 432 while rotating the swivel arm 434 while holding the substrate W by the clamp mechanism 420 and rotating it. By rubbing, the surface of the substrate W is cleaned. A cleaning nozzle (not shown) for supplying pure water is also provided on the back surface side of the substrate W, and the back surface of the substrate W is simultaneously cleaned with pure water sprayed from the cleaning nozzle.
The substrate W thus cleaned is spin-dried by rotating the spindle 428 at a high speed.

  Further, a cleaning cup 436 is provided that surrounds the periphery of the substrate W gripped by the clamp mechanism 420 and prevents the processing liquid from being scattered. The cleaning cup 436 moves up and down in accordance with the operation of the cleaning cup lifting and lowering cylinder 438. It has become.

  The post-processing chamber 28 may also be equipped with a cavitation function using cavitation. In addition, although not shown, a post-processing chamber equipped with a dry air unit for supplying dry air therein and supplying dry air into the post-processing chamber when the substrate is spin-dried is used. Is preferred. As a result, the substrate is thoroughly dried, and problems such as oxidation of the wiring portion due to adsorbed moisture and generation of water marks due to mistback can be avoided.

  FIG. 23 shows the plasma processing chamber 30 in FIG. The plasma processing chamber 30 includes a plasma processing unit 500 that carries a substrate W and carries out plasma processing, and a transfer unit 502 that blocks the atmosphere in the plasma processing unit 500 and the substrate processing apparatus. A gate valve 504 is disposed between the processing unit 500 and the transfer unit 502.

Inside the plasma processing unit 500, a substrate holder 506 that holds the substrate W and is grounded to be a lower electrode, and an electrode that is located above the substrate holder 506 and is connected to an RF (high frequency) power source 508 to be an upper electrode. Plates 510 are stored in parallel. The plasma processing unit 500 includes a vacuum line 514 having a vacuum pump 512 therein, and is connected to a vacuum exhaust system 516 that decompresses the inside of the plasma processing unit 500 and decompresses the substrate W. Furthermore, a gas supply path 518 a for introducing a plasma gas such as NH ₃ or N ₂ gas into the plasma processing unit 500 is provided inside the connecting portion 518 connecting the electrode plate 510 to the lower end. The plasma processing unit 500 is provided with a heater 520 for controlling the internal temperature.
On the other hand, inside the transfer unit 502, a cool plate 522 for housing and cooling the substrate is accommodated.

  Although not shown, the plasma processing chamber 30 is provided with a substrate transfer device such as a transfer robot that transfers the substrate W between the plasma processing unit 500 and the transfer unit 502.

In the plasma processing chamber 30, as described above, the substrate W that has been post-processed and dried is carried into the transfer unit 502. Then, the gate valve 504 is opened, the substrate W is carried into the plasma processing unit 500, and the gate valve 504 is closed. Next, the inside of the plasma processing unit 500 is depressurized to, for example, 1 to 10 Torr via the vacuum exhaust system 516, and at the same time, a plasma gas is introduced into the plasma processing unit 500 from the gas supply path 518a. The inside is made an atmosphere containing N ₂ , for example, an NH ₃ atmosphere or an N ₂ atmosphere. In this state, the electrode plate 510 is connected to the RF power source 508, thereby causing a glow discharge between both electrodes, that is, between the electrode plate 510 and the substrate W held by the substrate holder 506, and this glow discharge causes radical discharge. Nitrogen (N.) converted into nitrogen is infiltrated into the wiring protective film 9 from the surface of the wiring protective film 9, and the wiring protective film 9 is subjected to plasma treatment. At this time, the temperature in the plasma processing unit 500 is controlled via the heater 520.

  After the plasma processing is completed, the electrode plate 510 is disconnected from the RF power source 508, the inside of the plasma processing unit 500 is returned to the atmosphere, the gate valve 504 is opened, and the substrate after plasma processing is carried into the transfer unit 502. Then, the substrate is placed on the cool plate 522 in the transfer unit 502 to cool the substrate, and the cooled substrate is unloaded from the transfer unit 502.

  In addition, when hydrogen gas-dissolved water or electrolytic cathode water is used as the rinsing liquid in each of the above-described rinsing processes, an apparatus for dissolving hydrogen gas in ultrapure water or ultrapure water is electrolyzed in each unit. Devices can be attached, and hydrogen gas-dissolved water or electrolytic cathode water can be supplied from these devices to the substrate.

  FIG. 24 shows an example of a plasma processing chamber. This plasma processing chamber is configured to perform plasma processing at normal pressure, and includes a plasma processing unit 600 that carries a substrate W into the substrate and performs plasma processing. Inside the plasma processing unit 600, a substrate holder 602 that holds the substrate W and is grounded to be a lower electrode, and is connected to an RF (high frequency) power source 604 that is located above the substrate holder 602 and serves as an upper electrode. Electrode plates 606 and 607 are stored in parallel.

In the plasma processing unit 600, a gas supply path 608 for introducing a plasma gas such as NH ₃ or N ₂ gas is introduced between the electrode plates 606 and 607, and a purge gas is introduced into the plasma processing unit 600. A purge gas introduction path 610 and an exhaust path 612 for exhausting the inside of the plasma processing unit 600 are provided, and an exhaust pump 614 is installed in the exhaust path 612.

In this plasma processing chamber, the inside of the plasma processing unit 600 is made an atmosphere containing an inert gas, for example, an N ₂ atmosphere, and a reactive gas, for example, an NH ₃ / N ₂ mixed gas is introduced from a gas supply path 608. In this state, the electrode plate 606 is connected to the RF power source 604, whereby a glow discharge is caused between both electrodes, that is, between the electrode plate 606 and the other electrode plate 607, and radicalization is caused by this glow discharge. Nitrogen (N.) or hydrogen (H.) is moved to the surface of the substrate W by a gas flow, and enters the inside of the wiring protective film 9 from the surface of the wiring protective film 9, and plasma treatment is performed on the wiring protective film 9. Can be applied. Further, by rotating the substrate W, the uniformity in the processing surface can be improved. After the plasma processing, the inside of the plasma processing unit 600 can be purged by introducing the purge gas from the purge gas supply path 610 into the plasma processing unit 600 and exhausting it through the exhaust pump 614. it can.

It is sectional drawing which shows the state which formed the wiring protective film by the electroless plating. 1 is a plan layout view of a substrate processing apparatus according to an embodiment of the present invention. FIG. 3 is a process flow diagram in the substrate processing apparatus shown in FIG. 2. It is a figure which shows from a copper film formation in a multilayer wiring process to plasma processing to a wiring protective film in order of a process. It is sectional drawing which shows the state which formed the insulating film after performing the plasma processing to the wiring protective film in a multilayer wiring process. It is a front view at the time of the board | substrate delivery of a pre-processing chamber. It is a front view at the time of the chemical | medical solution process of a pre-processing chamber. It is a front view at the time of the rinse of a pre-processing chamber. It is sectional drawing which shows the process head at the time of the board | substrate delivery of a pre-processing chamber. It is the A section enlarged view of FIG. FIG. 11 is a view corresponding to FIG. 10 when the substrate of the pretreatment chamber is fixed. It is a systematic diagram of a pre-processing chamber. It is sectional drawing which shows the board | substrate head at the time of board | substrate delivery of an electroless-plating chamber. It is the B section enlarged view of FIG. FIG. 15 is a view corresponding to FIG. 14 illustrating the substrate head when the substrate is fixed in the electroless plating chamber. FIG. 15 is a view corresponding to FIG. 14 showing a substrate head during plating in the electroless plating chamber. It is a front view of partial cutting which shows a plating tank when the plating tank cover of an electroless plating chamber is closed. It is sectional drawing which shows the washing tank of an electroless-plating chamber. It is a systematic diagram of an electroless plating chamber. It is a perspective view which shows a washing | cleaning chamber and a post-processing chamber. It is a front view which shows a washing | cleaning chamber. It is a vertical front view which shows a post-processing chamber. It is a schematic diagram which shows a plasma processing chamber. It is a schematic diagram which shows the other example of a plasma processing chamber.

Explanation of symbols

8 Wiring 9 Wiring protective film 9a Nitride film 12 Load / unload unit 18, 20 Pretreatment chamber 22 Electroless plating chamber 26 Cleaning chamber 28 Post treatment chamber 30 Plasma treatment chamber 34 Transfer robot 40 Insulating film 56 Housing portion 58 Substrate holder 60 Processing head 86 Substrate fixing ring 100 Processing tank 102 Lid 200 Plating tank 202 Cleaning tank 204 Substrate head 230 Housing part 232 Head part 316 Heater 320 Heat exchanger 322 Heating device 324 Stirring pump 420 Clamp mechanism 422 Substrate stage 428 Spindle 432 Cleaning sponge 434 Swing arm 436 Cleaning cup 500, 600 Plasma processing unit 502 Transfer unit 504 Gate valve 506 Substrate holder 508 Power supply 510 Electrode plate 516 Vacuum exhaust system 5 8a gas supply passage 520 heater 522 cool plate

Claims (17)

In protecting the wiring by selectively forming a protective film on the exposed surface of the wiring formed on the surface of the substrate,
Perform pre-treatment on the substrate surface to be plated,
Selectively forming the protective film by performing electroless plating on the surface of the substrate to be plated that has undergone the pretreatment,
The substrate after the electroless plating is cleaned and dried,
A substrate processing method comprising performing plasma processing on the dried substrate surface. In protecting the wiring by selectively forming a protective film on the exposed surface of the wiring formed on the surface of the substrate,
Plasma treatment is performed on the substrate surface to be plated, and then pretreatment is performed.
The protective film is selectively formed by performing electroless plating treatment on the surface of the substrate to be plated that has undergone the pretreatment,
The substrate after the electroless plating treatment is cleaned and dried,
A substrate processing method comprising performing plasma processing on the dried substrate surface.   The substrate processing method according to claim 1, wherein the pretreatment includes a cleaning process for cleaning the substrate surface.   The substrate surface is cleaned by removing an inorganic acid having a pH of 2 or less, an organic acid having a chelating ability of pH 5 or less, a solution obtained by adding a chelating agent to an inorganic acid having a pH of 5 or less, and a corrosion inhibitor for wiring 4. The method according to claim 1, wherein the substrate surface is brought into contact with a chemical solution comprising an alkaline solution or an alkali solution of an amino acid, and then the cleaned substrate surface is rinsed with a rinse solution. The substrate processing method according to any one of the above.   5. The pretreatment includes an activation process of activating the surface of the substrate to be plated by applying a catalyst to the surface of the substrate to be plated on the cleaned substrate. The substrate processing method as described. For applying the catalyst to the surface of the substrate to be plated, the substrate surface to be plated is brought into contact with a chemical solution containing Pd, Ag, Ni, Co, Pt, Ru, or Au, or a chemical solution containing alkylamine borane or NaBH _4. 6. The substrate processing method according to claim 5, wherein the substrate surface after applying the catalyst is rinsed with a rinsing liquid.   The substrate processing method according to claim 1, wherein the plasma treatment is performed under an atmospheric pressure atmosphere. The plasma _{treatment, O 2, Ar, He,} H 2, N 2, NH 3, SO 2, SO 3, CF 4, C 2 F 6, CF 3, CFCF 2, comprise at least one of CCIF ₃ The substrate processing method according to claim 1, wherein the substrate processing method is performed in an atmosphere.   9. The substrate processing method according to claim 1, wherein a film thickness of 1/100 or more and 1/2 or less of a film formed on the substrate surface is modified by the plasma treatment.   The substrate processing method according to claim 1, wherein the plasma processing includes a plurality of processing steps in which any of a gas type, a flow rate, and a voltage is changed during the processing.   11. The substrate processing method according to claim 1, wherein the protective film formed by the electroless plating is a Co or Ni alloy film containing P or B. A substrate processing apparatus for selectively forming a protective film on an exposed surface of a wiring formed on a surface of a substrate,
A pretreatment chamber for pretreating the substrate surface;
An electroless plating chamber for selectively forming the protective film by performing an electroless plating process on the surface of the substrate to be plated subjected to the pretreatment;
A post-processing chamber for cleaning and drying the processed substrate;
A substrate processing apparatus having a plasma processing chamber for performing plasma processing on a substrate surface.   The pretreatment chamber treats the substrate surface with a chemical solution, removes the chemical solution from the substrate surface, applies a catalyst to the substrate surface, and removes the chemical solution used for applying the catalyst from the substrate surface. The substrate processing apparatus according to claim 12, comprising either one or both of the second pretreatment units.   The electroless plating chamber includes a plating tank, a plating solution circulation system, and a plating solution storage tank. It is possible to circulate between the plating solution storage tanks, and the circulating flow rate of the plating solution during plating standby is 2 to 20 L / min, and the circulating flow rate of the plating solution during plating treatment is 0 to 10 L / min. The substrate processing apparatus according to claim 12 or 13.   The substrate processing apparatus according to claim 12, wherein the post-processing chamber is made of a spin dryer.   16. The substrate according to claim 12, wherein the plasma processing chamber includes a plasma processing unit for performing plasma processing and a transfer unit for blocking an atmosphere in the apparatus from the plasma processing unit. Processing equipment.   17. The substrate processing apparatus according to claim 16, wherein the plasma processing unit has a heater for controlling temperature, and the transfer unit has a cool plate for cooling the substrate.

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