JP2008141051A - Method and apparatus for manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for manufacturing a semiconductor device in which burying capability of an Al film is improved. <P>SOLUTION: A control section coats the surface of a silicon substrate S having a via hole VH with a metal film BM1 (Ti film) and a metal nitride film BM2 (TiN film), and uses a CVD method to form an Al-CVD film P1 in the inside of the via hole VH coated with the metal nitride film BM2. Prior to burying the Al-CVD film P1, the control section sputters a part of the metal nitride film BM2 positioned on the bottom of the via hole VH to form a re-adhesive nitride film BMr on the side wall of the bottom of the via hole VH. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor device manufacturing method and a semiconductor device manufacturing apparatus.

  In the multilayer wiring technology of a semiconductor device, in order to form a plug connecting conductors, a filling technology is used in which a hole provided in an interlayer insulating film is filled with a metal material. Aluminum (Al) embedding technology is indispensable for realizing a plug having low electrical resistivity and high reliability.

As an Al embedding technique, a reflow sputtering method which is one of PVD (Physical Vapor Deposition) methods is known. In the reflow sputtering method, Al is sputtered onto a substrate having holes, and then the Al deposited thereon is fluidized by raising the temperature of the substrate. This flowing Al is responsible for improving the embedding property.

  However, when the design rule is reduced with the progress of high speed and high integration of the semiconductor device, the aspect ratio of the hole is increased and it becomes difficult to completely fill the inside of the hole by the PVD method. For example, in the case of a design rule in which the inner diameter of the hole is 0.18 μm or less, or the aspect ratio is 3 or more, in the PVD method, a void (hereinafter simply referred to as a void) is generated inside the plug. End up.

Therefore, in the Al embedding technique, conventionally, a CVD (Chemical Vapor Deposition) method has been proposed in order to improve the embedding property. In Patent Document 1, a nucleation liner film such as a Ti film, a TiN film, or a Ti / TiN film is formed on the inner wall of a hole, and an Al-CVD film and an Al-PVD film are formed on the nucleation liner film. Laminate. The nucleation liner film provides a surface on which an Al-CVD film can be grown. Thereby, the hole filling property and the reliability of the semiconductor device are improved.
JP 2002-280387A

In the Al-CVD film, a precursor (for example, MPA (Methylpyrrolidine Alane)) adheres to the surface of the base, and grows by electron transfer, that is, surface reaction with the surface.
On the other hand, the TiN film has poor adhesion to the Al-CVD film (or precursor) and cannot be expected to exchange electrons with the precursor. Therefore, when the outermost surface of the substrate is covered with a TiN film, the Al-CVD film is difficult to grow on the outermost surface of the substrate, and even if it grows, it grows very unevenly and the inside of the hole To form voids.

In addition, a high resistance Ti—Al alloy is formed between the Ti film and the Al—CVD film (or precursor). Therefore, when the inner wall of the hole is a Ti film, the Al-CVD film grows in a region where the precursor adhesion probability is high, that is, a region close to the hole opening, and the hole opening is filled before filling the hole. It will be blocked. The Ti film has Ti-
Since the Al alloy is formed, the wiring resistance is increased even when the design rule is wide.

As a result, while Patent Document 1 uses the CVD method, the base film suitable for the CVD method has not been sufficiently studied, and it has been difficult to improve the embedding characteristics.
The present invention has been made to solve the above problems, and provides a method for manufacturing a semiconductor device and an apparatus for manufacturing a semiconductor device, in which the embeddability of an Al film is improved.

  The inventors have found that the Al-CVD film embedding performance greatly depends on the method of forming the metal nitride film, while examining the Al-CVD film embedding performance. That is, before forming the Al-CVD film, a part of the metal nitride film is sputtered, and a part of the sputtered metal nitride film is reattached on the metal nitride film. The present inventors have found that this reattached metal nitride film functions as the nucleus of the Al-CVD film and grows the Al-CVD film.

  In order to achieve the above object, according to the first aspect of the present invention, a step of coating a metal film on the surface of a substrate having a recess, a step of coating a metal nitride film on the surface of the metal film, and the metal nitriding And embedding a first aluminum film in the concave portion covered with the film using a CVD method, wherein the bottom of the concave portion is embedded before the first aluminum film is embedded. The gist of the present invention is to sputter part of the metal nitride film located on the bottom and reattach part of the metal nitride film located on the bottom to the side wall of the bottom.

  According to this configuration, the first aluminum film grows from the bottom side wall. Therefore, the bottom up of the first aluminum film can be achieved, and the embedding property of the first aluminum film can be improved.

  According to a second aspect of the present invention, in the method of manufacturing a semiconductor device according to the first aspect, when the metal nitride film is coated, a part of the metal nitride film located at the bottom of the recess is sputtered. Then, a gist is to reattach a part of the metal nitride film located at the bottom to the side wall of the bottom.

  According to this configuration, when coating the metal nitride film, a part of the metal nitride film can be sputtered to reattach a part of the metal nitride film. Therefore, the coating of the metal nitride film and the reattachment of the metal nitride film can be performed simultaneously. As a result, the number of processing steps can be reduced and the throughput can be improved as compared with the case where the coating of the metal nitride film and the reattachment of the metal nitride film are performed separately.

  According to a third aspect of the present invention, in the method of manufacturing a semiconductor device according to the first or second aspect, the metal nitride film located at the bottom of the recess is sputtered to be part of the metal nitride film. The gist is to make the metal nitride film substantially flat.

  According to this configuration, excessive sputtering of the metal nitride film located at the bottom can be avoided, and the amount of reattachment of the metal nitride film can be stabilized. As a result, the concave portion can be embedded under higher reproducibility.

The invention according to claim 4 is the manufacturing method of the semiconductor device according to any one of claims 1 to 3, wherein the first aluminum film is annealed.
According to this configuration, the adhesion between the first aluminum film and the metal nitride film can be improved. Therefore, the state of the first aluminum film can be stabilized, and the embedding property of the first aluminum film can be improved more reliably.

  The invention according to claim 5 is the method for manufacturing a semiconductor device according to any one of claims 1 to 4, wherein the second aluminum film is further formed on the first aluminum film by using a PVD method. The gist is to laminate.

According to this configuration, the aluminum film is formed by the first aluminum film by the CVD method excellent in embeddability and the second aluminum film by the PVD method excellent in processing capability. Therefore, the throughput can be improved as compared with the case where all the first aluminum films are formed using the CVD method.

  The invention according to claim 6 is the method of manufacturing a semiconductor device according to any one of claims 1 to 5, wherein the metal film is made of any one of titanium, tantalum, nickel, and cobalt. In addition, the gist of the metal nitride film is any one of titanium nitride, tantalum nitride, nickel nitride, and cobalt nitride.

  In a seventh aspect of the present invention, the first aluminum film is formed on the substrate using a CVD method and a first film forming unit that covers the surface of the substrate with a metal film and a metal nitride film on the metal film. A second film forming unit; a transport unit that transports the substrate to the first film forming unit; and the second film forming unit; the transport unit and the first film forming unit are driven; and a recess is formed on the surface. The substrate was transported to the first film forming unit, the metal film and the metal nitride film were coated on the substrate, the transport unit and the second film forming unit were driven, and the metal nitride film was provided A control unit that transports the substrate to a second film forming unit to form the first aluminum film inside the recess covered with the metal nitride film, and the control unit includes the first film forming unit. A portion of the metal nitride film located at the bottom of the concave portion is sputtered to locate the bottom. It is reattached a portion of the metal nitride layer on the sidewalls of the bottom portion, and the gist.

  According to this configuration, the first aluminum film grows from the bottom sidewall due to the reattached metal nitride film. Therefore, the bottom up of the first aluminum film can be achieved, and the embedding property of the first aluminum film can be improved.

  According to an eighth aspect of the present invention, in the semiconductor device manufacturing apparatus according to the seventh aspect, the first film forming unit is formed by a reactive sputtering method using a target made of a constituent element of the metal film. The chamber is a chamber that coats the metal nitride film on the substrate and applies a bias voltage to the substrate to sputter a part of the metal nitride film located at the bottom of the recess, and the control unit includes the target When the metal nitride film is coated by sputtering, a bias voltage is applied to the substrate to sputter part of the metal nitride film located at the bottom of the recess.

  According to this configuration, when the metal nitride film is coated, the control unit can sputter part of the metal nitride film to reattach the sputtered particles to the bottom sidewall. Therefore, the coating of the metal nitride film and the reattachment of the metal nitride film can be performed simultaneously. As a result, the processing steps can be reduced and the throughput can be improved as compared with the case where the coating of the metal nitride film and the reattachment of the metal nitride film are performed separately.

  The invention according to claim 9 is the semiconductor device manufacturing apparatus according to claim 7 or 8, wherein the first film forming unit is a reactive sputtering method using a target made of a constituent element of the metal film. Forming a metal nitride film and applying a bias voltage to the substrate to sputter a part of the metal nitride film located at the bottom of the recess, and the control unit When the metal nitride film is coated by sputtering, a bias voltage is applied to the substrate to sputter a part of the metal nitride film located at the bottom of the recess, and the metal nitride film located at the bottom is substantially The gist is to make it flat.

  According to this configuration, the control unit can avoid excessive sputtering of the metal nitride film located at the bottom, and can stabilize the reattachment amount of the metal nitride film. As a result, the concave portion can be embedded under higher reproducibility.

  According to a tenth aspect of the present invention, in the semiconductor device manufacturing apparatus according to any one of the seventh to ninth aspects, the apparatus includes an annealing unit that raises the temperature of the substrate to a predetermined temperature. Transporting the substrate to the annealing unit, the control unit driving the transport unit to transport the substrate on which the first aluminum film is formed to the annealing unit, and driving the annealing unit. The gist is to raise the temperature of the substrate to the predetermined temperature and to anneal the first aluminum film.

  According to this configuration, the control unit anneals the first aluminum film to improve the adhesion between the first aluminum film and the metal nitride film. Therefore, the state of the first aluminum film can be stabilized, and the embedding property of the first aluminum film can be improved more reliably.

  According to an eleventh aspect of the present invention, there is provided the semiconductor device manufacturing apparatus according to any one of the seventh to tenth aspects, wherein the substrate is coated with a second aluminum film using a PVD method. A transfer unit that transfers the substrate to the third film forming unit, and the control unit drives the transfer unit to transfer the substrate on which the first aluminum film is formed to the third film forming unit. The gist is to transport the film to the film forming unit and drive the third film forming unit to further stack the second aluminum film on the first aluminum film.

  According to this configuration, the control unit stacks the second aluminum film by the PVD method having excellent processing capability on the first aluminum film by the CVD method having excellent embedding property. Accordingly, the throughput can be improved as compared with the case where all the aluminum films are formed using the CVD method.

  The invention according to claim 12 is the semiconductor device manufacturing apparatus according to any one of claims 7 to 11, wherein the first film forming portion is any one of titanium, tantalum, nickel, and cobalt. The gist is to mount a target consisting of three.

  As described above, according to the present invention, it is possible to provide a method for manufacturing a semiconductor device and an apparatus for manufacturing a semiconductor device with improved Al film embedding.

  Hereinafter, an embodiment embodying the present invention will be described. First, a semiconductor device manufacturing apparatus will be described. FIG. 1 is a plan view schematically showing a film forming apparatus 1 as a manufacturing apparatus. 2 and 3 are schematic cross-sectional views showing the barrier metal chamber 4 and the Al-CVD chamber 5 mounted on the film forming apparatus 1, respectively.

  In FIG. 1, a film forming apparatus 1 includes a load lock chamber (hereinafter simply referred to as an LL chamber) 2 and a core chamber 3 that constitutes a transfer unit. The film forming apparatus 1 includes a barrier metal chamber 4 as a first film forming unit, an Al-CVD chamber 5 as a second film forming unit, an annealing chamber 6 as an annealing unit, and a third film forming unit. And an Al-PVD chamber 7.

  The LL chamber 2 has an internal space (hereinafter simply referred to as a storage chamber 2a) that can be decompressed, and stores a plurality of silicon substrates S so that they can be unloaded and loaded. When the film formation process of the silicon substrate S is started, the LL chamber 2 depressurizes the storage chamber 2a so that the plurality of silicon substrates S can be carried out to the core chamber 3, respectively. When the film forming process for the silicon substrate S is completed, the LL chamber 2 opens the storage chamber 2 a to the atmosphere so that the silicon substrate S stored can be carried out of the film forming apparatus 1.

  The core chamber 3 has an internal space that can be depressurized (hereinafter simply referred to as a transfer chamber 3a), and a transfer robot 3b for transferring the silicon substrate S is mounted on the transfer chamber 3a. When starting the film forming process for the silicon substrate S, the transfer robot 3b carries the silicon substrate S before the film forming process from the LL chamber 2 to the core chamber 3. The transfer robot 3b sequentially transfers the loaded silicon substrates S along the counterclockwise direction in FIG. That is, the transfer robot 3b transfers the loaded silicon substrate S in the order of the barrier metal chamber 4, the Al-CVD chamber 5, the annealing chamber 6, and the Al-PVD chamber 7. When the film forming process of the silicon substrate S is completed, the transfer robot 3b carries out the silicon substrate S after the film forming process from the core chamber 3 to the LL chamber 2.

  The barrier metal chamber 4 is a chamber for coating a metal film on the silicon substrate S using a sputtering method. As the metal film, for example, a titanium (Ti) film, a tantalum (Ta) film, a nickel (Ni) film, a cobalt (Co) film, or the like can be used. The barrier metal chamber 4 is a chamber for coating a metal nitride film on the silicon substrate S by using a reactive sputtering method. As the metal nitride film, for example, a titanium nitride (TiN) film, a tantalum nitride (TaN) film, a nickel nitride (NiN) film, or a cobalt nitride (CoN) film can be used.

In FIG. 2, the barrier metal chamber 4 has a chamber body 11 having an internal space (hereinafter simply referred to as a film forming chamber 4a) that can be decompressed. An argon (Ar) mass flow controller MC1 is connected to the chamber body 11 via a supply pipe IL1, and a nitrogen (N ₂ ) mass flow controller MC2 is connected via a supply pipe IL2. Each mass flow controller MC1, MC2 adjusts Ar gas and N ₂ gas to a predetermined flow rate and supplies them to the film forming chamber 4a.

An exhaust system 12 including a turbo molecular pump, a dry pump, and the like is connected to the chamber body 11 via an exhaust pipe OL1. The exhaust system 12 evacuates Ar gas or a mixed gas of Ar gas and N ₂ gas supplied to the film forming chamber 4a, and depressurizes the film forming chamber 4a to a predetermined pressure value.

  A substrate holder 13 for placing the silicon substrate S is disposed in the chamber body 11. The substrate holder 13 places the silicon substrate S carried in from the core chamber 3, and positions and fixes the silicon substrate S at a predetermined position in the film forming chamber 4a.

A substrate electrode 14 is provided inside the substrate holder 13. The substrate electrode 14 is connected to a substrate bias power supply G1 and receives predetermined AC power from the substrate bias power supply G1. When the plasma is generated in the film forming chamber 4a, the substrate electrode 14 that receives AC power has a negative potential with respect to the plasma space, that is, functions as a cathode and draws ionic particles into the silicon substrate S. Improve the straightness of the. In addition, the substrate electrode 14 that receives AC power draws ion particles (for example, argon ions) into the surface of the silicon substrate S when plasma is generated in the film formation chamber 4a, and a metal film or metal nitride on the silicon substrate S. A part of the film is sputtered. That is, the barrier metal chamber 4 forms a metal film or a metal nitride film by a SIS (Self-Ionized Plasma Sputtering) method in which a bias voltage is applied to the silicon substrate S.

A shield 15 formed in a substantially cylindrical shape is disposed above the substrate holder 13. The shield 15 is connected to the shield power supply G2, and receives predetermined DC power from the shield power supply G2. The shield 15 that receives direct current power functions as a positive potential, that is, an anode with respect to the plasma space when plasma is generated in the film forming chamber 4a, and deflects the traveling direction of the ion particles toward the silicon substrate S.

  A target 16 formed in a disk shape is disposed immediately above the shield 15. The target 16 contains 90% or more, preferably 95% or more of the main component of the metal film, that is, Ti, Ta, Ni or Co, and the remainder contains a metal other than the metal element, such as copper or silicon. Can be used.

  A target electrode 17 is disposed on the upper side of the target 16. The target electrode 17 is connected to the target power supply G3, and receives predetermined direct current or alternating current power from the target power supply G3. When the plasma is generated in the film forming chamber 4a, the target electrode 17 that receives direct current or alternating current power functions as a negative potential with respect to the plasma space, that is, as a cathode and causes the target 16 to be sputtered. The target electrode 17 makes the target 16 face the silicon substrate S and holds the distance between the target 16 and the silicon substrate S at a predetermined distance (for example, a distance longer than the diameter of the silicon substrate S).

  A magnetic circuit 18 is disposed above the target electrode 17. The magnetic circuit 18 forms a magnetron magnetic field along the inner surface of the target 16 and stabilizes the plasma to increase its density when plasma is generated in the film forming chamber 4a.

  When the barrier metal chamber 4 coats the surface of the silicon substrate S with a metal film, the mass flow controller MC1 supplies Ar gas at a predetermined flow rate, and the exhaust system 12 reduces the film forming chamber 4a to a predetermined pressure value. . In this state, the barrier metal chamber 4 applies a predetermined electric power to each of the power supplies G1, G2, and G3, and causes the target 16 to be sputtered on the high-density Ar plasma. Then, the sputtered metal particles are drawn into the surface of the silicon substrate S along the substantially normal direction of the silicon substrate S to cover the surface of the silicon substrate S. Thereby, the barrier metal chamber 4 forms a metal film with excellent step coverage on the surface of the silicon substrate S.

When the metal nitride film is coated on the surface of the silicon substrate S, the barrier metal chamber 4 supplies Ar gas and N ₂ gas at a predetermined flow rate by the mass flow controllers MC1 and MC2, respectively, and the film forming chamber 4a by the exhaust system 12. Is reduced to a predetermined pressure value. In this state, the barrier metal chamber 4 applies a predetermined power to each of the power supplies G1, G2, and G3, and causes the target 16 to be sputtered by high-density Ar / N ₂ plasma. Then, the sputtered metal particles are drawn into the surface of the silicon substrate S along the substantially normal direction of the silicon substrate S, and reacted with N ₂ plasma to form a metal nitride film. Thereby, the barrier metal chamber 4 forms a metal nitride film having excellent step coverage on the surface of the silicon substrate S.

  In FIG. 1, an Al-CVD chamber 5 is a chamber for forming a first aluminum film (hereinafter simply referred to as an Al-CVD film) on a silicon substrate S using a CVD method.

  In FIG. 3, the Al-CVD chamber 5 has a chamber body 21 having an internal space (hereinafter simply referred to as a film forming chamber 5a) that can be decompressed. The chamber main body 21 is connected to a transport system 22 for transporting an Al-CVD film source material (hereinafter simply referred to as an Al film source) to the film forming chamber 5a via a supply pipe IL3.

As the Al film raw material, for example, DMAH (Dimethyl Aluminum Hydride), TMAA (Trimethylamine Alane), MPA (Methylpyrrolidine Alane)) can be used. For the transport system 22, for example, a bubbling system that regulates the flow rate of the Al film material by the flow rate of the carrier gas can be used. Transportation system 2
2 includes a vapor flow control system that controls the flow rate of the Al film material in a gaseous state by a mass flow controller, and a liquid phase transport system that directly transports the Al film material in a liquid state (LDS: liquid delivery system) can be used.

  An exhaust system 23 including a dry pump is connected to the chamber body 21 via an exhaust pipe OL2. The exhaust system 23 exhausts the Al film raw material and the carrier gas supplied to the film forming chamber 5a to reduce the film forming chamber 5a to a predetermined pressure value.

  The chamber body 21 is provided with a substrate holder 24 for placing the silicon substrate S thereon. The substrate holder 24 places the silicon substrate S carried in from the core chamber 3, and positions and fixes the silicon substrate S at a predetermined position in the film forming chamber 5a. The substrate holder 24 is provided with a heater 26 connected to the heater power supply 25. When the silicon substrate S is placed, the heater 26 raises the temperature of the silicon substrate S to a predetermined temperature.

  A shower plate 27 formed in a disk shape is disposed immediately above the substrate holder 24. The shower plate 27 has a plurality of nozzles 28 communicating with the supply pipe IL3 on the side surface facing the silicon substrate S. Each nozzle 28 supplies the Al film raw material supplied from the transport system 22 toward the film formation chamber 5a, that is, the surface of the silicon substrate S.

  In the Al-CVD chamber 5, when an Al-CVD film is formed on the surface of the silicon substrate S, the temperature of the silicon substrate S is raised to a predetermined temperature by the substrate holder 24, and an Al film material is formed by the transport system 22. 5a is supplied. The Al film raw material supplied to the film forming chamber 5a adheres to the surface of the silicon substrate S and grows by electron transfer, that is, surface reaction with the surface.

  Here, when the metal nitride film with the metal film as the base constitutes the surface of the silicon substrate S, the Al film raw material has poor adhesion with the metal nitride film, and also exchanges electrons with the metal nitride film. Therefore, it is difficult to initiate a surface reaction on the metal nitride film.

  The inventors have found that the Al-CVD film embedding performance greatly depends on the method of forming the metal nitride film, while examining the Al-CVD film embedding performance. That is, before forming the Al-CVD film, a part of the metal nitride film is sputtered, and a part of the sputtered metal nitride film is reattached on the metal nitride film. The inventors have found that the reattached metal nitride film functions as a nucleus of the Al-CVD film and grows the Al-CVD film. Hereinafter, in the metal nitride film, the reattached metal nitride film is referred to as a “reattachment film”.

  In FIG. 1, the annealing chamber 6 has an internal space (hereinafter simply referred to as annealing chamber 6a) for heat-treating the silicon substrate S at a high temperature. When the silicon substrate S is transferred from the core chamber 3, the annealing chamber 6 accommodates the silicon substrate S in the annealing chamber 6 a and heat-treats the silicon substrate S in an inert gas (for example, Ar) atmosphere.

  In FIG. 1, an Al-PVD chamber 7 has an internal space (hereinafter simply referred to as a film forming chamber 7a) for forming an aluminum film on a silicon substrate S by using a sputtering method. When the silicon substrate S is transferred from the core chamber 3, the Al-PVD chamber 7 stores the silicon substrate S in the film formation chamber 7 a, sputters an Al target for forming an aluminum film, and Then, an aluminum film is formed. The aluminum film formed by the Al-PVD chamber 7 is referred to as a second aluminum film (hereinafter simply referred to as an Al-PVD film).

Next, the electrical configuration of the film forming apparatus 1 will be described. FIG. 4 is an electric block circuit diagram showing an electrical configuration of the film forming apparatus 1.
In FIG. 4, the control unit 31 causes the film forming apparatus 1 to execute various processing operations (for example, a transfer process of the silicon substrate S and a film forming process of the silicon substrate S). The control unit 31 includes a CPU for executing various arithmetic processes, a RAM for storing various data, a ROM for storing various control programs, a hard disk, and the like. For example, the control unit 31 reads a film forming process program stored in the hard disk and causes the film forming process to be executed according to the film forming process program.

  An input / output unit 32 is connected to the control unit 31. The input / output unit 32 includes various operation switches such as a start switch and a stop switch, and various display devices such as a liquid crystal display. The input / output unit 32 inputs data used for various processing operations to the control unit 31 and outputs data related to the processing status of the film forming apparatus 1. The input / output unit 32 stores data on film formation parameters (for example, gas flow rate, internal space pressure value, silicon substrate S temperature, film formation time, output values of the power supplies G1, G2, and G3). The data is input to the control unit 31 as data Id. That is, the input / output unit 32 controls the film formation parameters for forming the metal film, the metal nitride film, the Al-CVD film, and the Al-PVD film, and the parameters for executing the annealing process as the film formation condition data Id. Input to the unit 31. The control unit 31 receives the film forming condition data Id input from the input / output unit 32, and causes each film forming process to be executed under the film forming condition corresponding to the film forming condition data Id.

  An LL chamber driving circuit 33 for driving and controlling the LL chamber 2 is connected to the control unit 31. The LL chamber drive circuit 33 detects the state of the LL chamber 2 and inputs the detection result to the control unit 31. For example, the LL chamber drive circuit 33 detects the pressure value of the storage chamber 2 a and inputs a detection signal related to the pressure value to the control unit 31. The control unit 31 uses the detection signal input from the LL chamber drive circuit 33 and outputs a drive control signal corresponding to the LL chamber drive circuit 33 to the LL chamber drive circuit 33. The LL chamber drive circuit 33 responds to the drive control signal from the control unit 31 and allows the silicon substrate S to be loaded or unloaded by reducing the pressure in the storage chamber 2a or opening it to the atmosphere.

  A core chamber drive circuit 34 for driving and controlling the core chamber 3 is connected to the control unit 31. The core chamber drive circuit 34 detects the state of the core chamber 3 and inputs the detection result to the control unit 31. The core chamber drive circuit 34 detects the arm position of the transfer robot 3b, for example, and inputs a detection signal related to the arm position to the control unit 31. The control unit 31 uses the detection signal input from the core chamber drive circuit 34 and outputs a drive control signal corresponding to the core chamber drive circuit 34 to the core chamber drive circuit 34. The core chamber drive circuit 34 responds to the drive control signal from the control unit 31, and converts the silicon substrate S into the LL chamber 2, the core chamber 3, the barrier metal chamber 4, the Al-CVD chamber 5, the annealing chamber 6, and the Al-PVD chamber. Transport in the order of 7.

A barrier metal chamber drive circuit 35 for driving and controlling the barrier metal chamber 4 is connected to the control unit 31. The barrier metal chamber drive circuit 35 detects the state of the barrier metal chamber 4 and inputs the detection result to the control unit 31. The barrier metal chamber drive circuit 35 detects, for example, the pressure value of the film forming chamber 4a, the actual flow rate of each gas type, the output value of each power source G1, G2, G3, and the like, and sends detection signals regarding these parameters to the control unit 31. input. The control unit 31 uses the detection signal input from the barrier metal chamber drive circuit 35 and outputs a drive control signal corresponding to the film formation condition data Id to the barrier metal chamber drive circuit 35. The barrier metal chamber drive circuit 35 drives each mass flow controller MC1, MC2, exhaust system 12, each power supply G1, G2, G3, etc. in response to a drive control signal from the control unit 31, and corresponds to the film formation condition data Id. The film forming process of the metal film and the metal nitride film is executed under the film forming conditions.

  An Al-CVD chamber driving circuit 36 for driving and controlling the Al-CVD chamber 5 is connected to the control unit 31. The Al-CVD chamber drive circuit 36 detects the state of the Al-CVD chamber 5 and inputs the detection result to the control unit 31. The Al-CVD chamber drive circuit 36 detects, for example, the pressure value of the film forming chamber 5a, the actual flow rate of the Al film material, the actual temperature of the silicon substrate S, and the like, and inputs detection signals related to these parameters to the control unit 31. The control unit 31 uses the detection signal input from the Al-CVD chamber drive circuit 36 and outputs a drive control signal corresponding to the film formation condition data Id to the Al-CVD chamber drive circuit 36. The Al-CVD chamber drive circuit 36 drives the transport system 22, the exhaust system 23, the heater power supply 25, etc. in response to the drive control signal from the control unit 31, under the film formation conditions corresponding to the film formation condition data Id. Then, the film forming process of the Al-CVD film is executed.

  An annealing chamber drive circuit 37 for driving and controlling the annealing chamber 6 is connected to the control unit 31. The annealing chamber drive circuit 37 detects the state of the annealing chamber 6 and inputs the detection result to the control unit 31. The annealing chamber drive circuit 37 detects, for example, the pressure value of the annealing chamber 6a, the actual temperature of the silicon substrate S, and the like, and inputs detection signals regarding these parameters to the control unit 31. The control unit 31 uses the detection signal input from the annealing chamber driving circuit 37 and outputs a driving control signal corresponding to the film forming condition data Id to the annealing chamber driving circuit 37. In response to the drive control signal from the control unit 31, the annealing chamber drive circuit 37 executes the annealing process for the silicon substrate S under the film formation conditions corresponding to the film formation condition data Id.

  An Al-PVD chamber driving circuit 38 for driving and controlling the Al-PVD chamber 7 is connected to the control unit 31. The Al-PVD chamber drive circuit 38 detects the state of the Al-PVD chamber 7 and inputs the detection result to the control unit 31. The Al-PVD chamber drive circuit 38 detects, for example, the pressure value of the film forming chamber 7 a and the power value applied to the Al target, and inputs detection signals related to these parameters to the control unit 31. The control unit 31 uses the detection signal input from the Al-PVD chamber drive circuit 38 and outputs a drive control signal corresponding to the film formation condition data Id to the Al-PVD chamber drive circuit 38. In response to the drive control signal from the control unit 31, the Al-PVD chamber drive circuit 38 executes the Al-PVD film formation process under the film formation conditions corresponding to the film formation condition data Id.

Next, a method for manufacturing a semiconductor device using the film forming apparatus 1 will be described. 5 to 9 are process diagrams showing the manufacturing process of the semiconductor device.
First, a plurality of silicon substrates S having a diameter of 200 [mm] are set in the LL chamber 2. As shown in FIG. 5, the silicon substrate S includes a metal wiring ML and an interlayer insulating film DL stacked on the metal wiring ML. Various metal materials such as Al wiring and copper wiring can be used for the metal wiring ML. Various insulating materials such as an insulating film material having a low dielectric constant and a silicon oxide film can be used for the interlayer insulating film DL.

  On the surface of the interlayer insulating film DL (upper surface in FIG. 5), a hole (via hole VH (Via hole)) as a recess penetrating to the metal wiring ML is formed. The inner diameter Rvh of the via hole VH is 145 [nm], and the depth Dvh of the via hole VH is 600 [nm]. That is, the surface of the silicon substrate S has a via hole VH having an aspect ratio of 4.13.

The control unit 31 receives the film formation condition data Id from the input / output unit 32. Further, the control unit 31 drives the LL chamber 2 and the core chamber 3 via the LL chamber driving circuit 33 and the core chamber driving circuit 34, and transports the silicon substrate S in the storage chamber 2 a to the barrier metal chamber 4.

  When the silicon substrate S is carried into the film forming chamber 4a, the control unit 31 drives the barrier metal chamber 4 via the barrier metal chamber driving circuit 35, and the metal under the film forming conditions corresponding to the film forming condition data Id. The film BM1 is coated (hereinafter simply referred to as a metal film process). As shown in FIG. 5, in this metal film process, the metal film BM1 is covered over the entire inner wall of the via hole VH. That is, the inside of the via hole VH is covered with the metal film BM1 having high adhesion with the interlayer insulating film DL.

As the film forming conditions in the metal film step, the following conditions are preferably mentioned.
-Main component of target 16: Ti
Ar flow rate: 5 to 100 [sccm]
Film forming pressure: 1 × 10 ^{−2 to} 0.5 [Pa]
-Substrate temperature: Room temperature to 350 [° C]
-Substrate bias power supply: 0 [W]
・ Deposition rate: 10-200 [nm / min]
Film thickness: 5 to 40 [nm] (more preferably 15 [nm])
When the pressure in the film forming chamber 4a is higher than 10 [Pa], the incident direction of the sputtered metal particles (Ti particles) is greatly inclined from the normal direction of the silicon substrate S, and the metal film BM1 (Ti film) The step coverage is significantly impaired. Similarly, the step coverage of the Ti film is significantly impaired even under conditions where the deposition rate is higher than 500 [nm / min].

  When the metal film BM1 is formed, the control unit 31 drives the barrier metal chamber 4 via the barrier metal chamber drive circuit 35 and covers the metal nitride film BM2 under the film formation conditions corresponding to the film formation condition data Id. (Hereinafter simply referred to as a metal nitride film process).

  As shown in FIGS. 6 and 7, in the metal nitride film process, the metal particles reach the bottom of the via hole VH by the amount of using the SIS method, and the metal nitride film BM2 covers the entire metal film BM1. To do.

  At this time, the metal particles incident on the via hole VH are affected by the shadowing effect, and form a mountain-shaped metal nitride film BM2 at the bottom of the via hole VH. Here, the mountain-shaped metal nitride film BM2 (two-dot chain line portion in FIG. 6) located at the bottom of the via hole VH is referred to as a bottom nitride film BMs. In the process of forming the metal nitride film BM2, the bottom nitride film BMs is sputtered by ion particles (for example, Ar ions) incident on the via hole VH and reattached to the bottom side wall of the via hole VH. Here, the reattachment film (the part with gradation in FIG. 6) of the sputtered bottom nitride film BMs is referred to as a reattachment nitride film BMr.

  The control unit 31 makes the metal nitride film BM2 located at the bottom of the via hole VH flat according to the film formation parameters (for example, the film formation pressure and the output value of the substrate bias power supply G1) according to the film formation condition data Id. Then, a reattached nitride film BMr is formed. That is, the control unit 31 forms the redeposited nitride film BMr as much as the bottom nitride film BMs, and normalizes the thickness of the redeposited nitride film BMr to a predetermined film thickness.

As the film forming conditions in the metal nitride film process, the following conditions are preferably mentioned.
-Main component of target 16: Ti
Ar flow rate: 5 to 100 [sccm]
・ N ₂ flow rate: 5 to 100 [sccm]
Film forming pressure: 5 × 10 ⁻² to 1 [Pa]
-Substrate temperature: Room temperature to 350 [° C]
Substrate bias power source: 200 to 600 [W] (more preferably 600 [W])
・ Deposition rate: 10-200 [nm / min]
When the pressure in the film forming chamber 4a is increased from 10 [Pa], the incident direction of the sputtered metal particles (Ti particles) is greatly inclined from the normal direction of the silicon substrate S, and the metal nitride film (TiN film) The step coverage is significantly impaired. Similarly, the step coverage of the TiN film is significantly impaired even under conditions where the deposition rate is higher than 500 [nm / min]. When the output value of the substrate bias power supply G1 is smaller than 100 [W], the bottom nitride film BMs is not sufficiently sputtered and the reattached nitride film BMr is not formed. Conversely, when the output value of the substrate bias power supply G1 exceeds 800 [W], sputtering by ion particles becomes excessive, and the metal nitride film BM2 located at the bottom of the via hole VH and the metal nitride film BM2 located at the opening of the via hole VH. The film thickness becomes insufficient.

  When the metal nitride film BM2 is formed, the control unit 31 drives the Al-CVD chamber 5 via the Al-CVD chamber drive circuit 36 and performs Al-CVD under the film formation conditions corresponding to the film formation condition data Id. A film P1 is formed (hereinafter simply referred to as an Al-CVD film process).

  As shown in FIG. 7, in this Al-CVD film process, the reattached nitride film BMr is formed only on the side wall at the bottom of the via hole VH. Therefore, the nucleus of the Al-CVD film P1 is formed at the bottom of the via hole VH, and the Al-CVD film P1 starts to grow from the bottom of the via hole VH. On the other hand, since the redeposition film is not formed above the via hole VH, the nucleus of the Al-CVD film P1 is not formed, and the metal nitride film BM2 continues to maintain the opening diameter of the via hole VH.

  Moreover, the outermost surface of the Al-CVD film P1 exhibits a mountain shape protruding upward in the process of growth. For this reason, the Al-CVD film P1 does not protrude from the side wall of the via hole VH and continues to grow toward the opening while exhibiting a shape in which voids are difficult to form.

  As a result, as shown in FIG. 7, the control unit 31 bottoms up the Al—CVD film P <b> 1 while maintaining the state where the opening of the via hole VH is opened. Then, as shown in FIG. 8, the control unit 31 grows the Al-CVD film P1 only inside the via hole VH, completely fills the inside of the via hole VH with the Al-CVD film P1, and forms the Al-CVD film P1. Finish the film formation.

As film formation conditions in the Al-CVD film process, the following conditions are preferable.
・ MPA flow rate: 1 to 100 [sccm]
-Film formation pressure: 5 to 1500 [Pa]
Substrate temperature: 80 to 300 [° C.] (more preferably 100 [° C.])
・ Deposition rate: 10-300 [nm / min]
Note that when the pressure in the film forming chamber 5a falls below 1 [Pa], the film forming speed of the Al-CVD film P1 is significantly impaired due to the decrease in MPA concentration. Conversely, when the pressure in the film forming chamber 5a increases from 2000 [Pa], the uniformity of MPA, that is, the film thickness uniformity of the Al-CVD film P1 is impaired. Moreover, when the substrate temperature falls below 80 [° C.], the deposition rate of the Al-CVD film P1 is significantly impaired.

When the Al-CVD film P1 is formed, the control unit 31 drives the annealing chamber 6 via the annealing chamber driving circuit 37, and the silicon substrate S, that is, Al under the film forming conditions corresponding to the film forming condition data Id. -The CVD film P1 is annealed (hereinafter simply referred to as an annealing step). As the heat treatment conditions in this annealing step, the following conditions are preferable.
Film deposition pressure: 1 × 10 ^{−5 to} 500 [Pa]
Substrate temperature: 250 to 500 [° C.] (more preferably, 460 [° C.])
・ Processing time: 0.1-10 [min]
In the annealing step, the adhesion between Al and the metal nitride film is improved. Therefore, when another film is stacked on the Al-CVD film, it is possible to avoid outflow or peeling of the Al-CVD film from the via hole VH. As a result, the via hole VH can be completely filled with the Al-CVD film even in the post-process, and a more reliable via plug can be formed.

  When the annealing step is finished, the control unit 31 drives the Al-PVD chamber 7 via the Al-PVD chamber drive circuit 38, and the Al-PVD film P2 under the film formation conditions corresponding to the film formation condition data Id. (Hereinafter, simply referred to as an Al-CVD film process). The Al-PVD film P2 is a sacrificial film for planarizing the surface of the Al-CVD film P1, and most of it is polished in the planarization process. For this reason, as the film formation conditions in the Al-PVD film process, conditions in which the film formation speed is high (for example, conditions in which electric power applied to the Al target is large) are preferable in order to shorten the processing time.

According to the said embodiment, there exist the following effects.
(1) In the above embodiment, the controller 31 covers the surface of the silicon substrate S having the via hole VH with the metal film BM1 (Ti film) and the metal nitride film BM2 (TiN film), and covers the metal nitride film BM2. An Al-CVD film P1 was formed inside the formed via hole VH using the CVD method. Then, before embedding the Al-CVD film P1, the control unit 31 sputters a part of the metal nitride film BM2 located at the bottom of the via hole VH to form a reattached nitride film BMr on the side wall of the bottom of the via hole VH. It was.

  Therefore, an Al-CVD film can be grown from the bottom of the via hole VH, and the opening of the via hole VH can be continuously opened. As a result, bottom-up of the Al-CVD film can be achieved, and the embedding property of the Al-CVD film can be improved.

  (2) In the embodiment described above, the control unit 31 sputters the bottom nitride film BMs in the process of forming the metal nitride film BM2, thereby forming the reattached nitride film BMr. Therefore, the coating of the metal nitride film BM2 and the formation of the redeposition nitride film BMr can be performed simultaneously. As a result, the number of via plug processing steps can be reduced and the throughput can be improved as compared with the case where the coating of the metal nitride film BM2 and the reattached nitride film BMr are performed separately.

  (3) In the above embodiment, the control unit 31 sputters the bottom nitride film BMs so that the metal nitride film BM2 located at the bottom of the via hole VH is substantially flat. Therefore, excessive sputtering of the metal nitride film BM2 located at the bottom can be avoided, and the reattachment amount of the reattachment nitride film BMr can be normalized. As a result, the via hole VH can be filled with the Al-CVD film P1 under higher reproducibility.

  (4) In the above embodiment, the control unit 31 anneals the Al-CVD film P1. Therefore, the adhesion between the Al-CVD film P1 and the metal nitride film BM2 can be improved, and the embedded state of the Al-CVD film P1 can be stabilized.

(5) In the said embodiment, the control part 31 laminates | stacks the Al-PVD film | membrane P2 further using the PVD method on the Al-CVD film | membrane P1. Therefore, a via plug can be formed by the Al-CVD film P1 by the CVD method having excellent embedding property and the Al-PVD film P2 by the PVD method having excellent processing ability. As a result, the throughput can be improved as compared with the case where all via plugs are formed using the CVD method.

  (6) In the above embodiment, the metal film BM1 and the metal nitride film BM2 can be formed in the same chamber, that is, the barrier metal chamber 4. Therefore, the configuration of the film forming apparatus 1 can be simplified as compared with the case where the metal film BM1 and the metal nitride film BM2 are covered by different chambers.

In addition, you may implement the said embodiment in the following aspects.
In the above embodiment, the concave portion is embodied as the via hole VH. For example, the recess may be embodied as a contact hole. Further, as shown in FIG. 10, a groove for forming a damascene wiring may be embodied as a concave portion.

  In the above embodiment, the metal nitride film BM2 is formed by the SIS method, and the reattached nitride film BMr is formed in the process of forming the metal nitride film BM2. For example, after forming the metal nitride film BM2 with the output value of the substrate bias power supply G1 being 0 [W], the metal nitride film BM2 is sputtered separately to form the reattached nitride film BMr. May be.

  In the above embodiment, the barrier metal chamber 4 is embodied as a DC magnetron type chamber. For example, the barrier metal chamber 4 may be embodied as a simple DC sputtering method, AC sputtering method, or AC magnetron chamber. That is, the barrier metal chamber 4 may be any chamber that sputters the bottom nitride film BMs to form the reattached nitride film BMr.

  In the above embodiment, the annealing part is embodied in the annealing chamber 6. For example, the annealing unit may be embodied as a heating unit (substrate stage or lamp heater) that enables annealing, and may be provided in the film forming chamber 7 a of the Al-PVD chamber 7. According to this, the configuration of the film forming apparatus 1 can be simplified as much as the annealing chamber 6 is not required.

  In the above embodiment, the second aluminum film is formed by the Al-PVD chamber 7. For example, the second aluminum film may be formed by the Al-CVD chamber 5. According to this, the configuration of the film forming apparatus 1 can be simplified as much as the Al-PVD chamber 7 is not required.

1 is a schematic plan view showing a film forming apparatus. The schematic sectional drawing which shows a barrier metal chamber. The schematic sectional drawing which shows an Al-CVD chamber. The electric block circuit diagram which shows the electrical constitution of the film-forming apparatus. Process drawing which shows the manufacturing method of a semiconductor device. Process drawing which shows the manufacturing method of a semiconductor device. Process drawing which shows the manufacturing method of a semiconductor device. Process drawing which shows the manufacturing method of a semiconductor device. Process drawing which shows the manufacturing method of a semiconductor device. Process drawing which shows the manufacturing method of the semiconductor device in the example of a change.

Explanation of symbols

BM1 ... Metal film, BM2 ... Metal nitride film, P1 ... First aluminum film, P2 ... Second aluminum film, S ... Silicon substrate, VH ... Via hole as a recess, 1 ... Film forming apparatus as a semiconductor device manufacturing apparatus, DESCRIPTION OF SYMBOLS 3 ... Core chamber as a conveyance part, 4 ... Barrier metal chamber as a 1st film-forming part, 5 ... Al-CVD chamber as a 2nd film-forming part, 6 ... Annealing chamber as an annealing part, 7 ... 3rd composition Al-PVD chamber as a film part, 16 ... target, 31 ... control part.

Claims (12)

Coating a metal film on the surface of the substrate having a recess;
Coating the surface of the metal film with a metal nitride film;
A step of embedding a first aluminum film using a CVD method inside the recess covered with the metal nitride film;
A method of manufacturing a semiconductor device having
Before embedding the first aluminum film, a part of the metal nitride film located at the bottom of the recess is sputtered, and a part of the metal nitride film located at the bottom is reattached to the side wall of the bottom. ,
A method of manufacturing a semiconductor device. A method of manufacturing a semiconductor device according to claim 1,
When coating the metal nitride film, a part of the metal nitride film located at the bottom of the recess is sputtered, and a part of the metal nitride film located at the bottom is reattached to the side wall of the bottom. ,
A method of manufacturing a semiconductor device. A method of manufacturing a semiconductor device according to claim 1 or 2,
Sputtering a part of the metal nitride film located at the bottom of the recess to make the metal nitride film located at the bottom substantially flat,
A method of manufacturing a semiconductor device. It is a manufacturing method of the semiconductor device according to any one of claims 1 to 3,
Annealing the first aluminum film;
A method of manufacturing a semiconductor device. It is a manufacturing method of the semiconductor device according to any one of claims 1 to 4,
A second aluminum film is further laminated on the first aluminum film using a PVD method;
A method of manufacturing a semiconductor device. It is a manufacturing method of the semiconductor device according to any one of claims 1 to 5,
The metal film is made of any one of titanium, tantalum, nickel, and cobalt;
The metal nitride film is made of any one of titanium nitride, tantalum nitride, nickel nitride, and cobalt nitride;
A method of manufacturing a semiconductor device. A first film-forming part for coating a metal film on the surface of the substrate and coating the metal film with a metal nitride film;
A second film forming unit that forms a first aluminum film on the substrate using a CVD method;
A transport unit for transporting the substrate to the first film forming unit and the second film forming unit;
Driving the transport unit and the first film forming unit, transporting the substrate having a recess on the surface to the first film forming unit to cover the metal film and the metal nitride film on the substrate; The transporting unit and the second film forming unit are driven, the substrate having the metal nitride film is transported to the second film forming unit, and the first aluminum film is formed inside the recess covered with the metal nitride film. And a control unit for forming
The controller is
Driving the first film forming unit to sputter part of the metal nitride film located at the bottom of the recess, and reattaching part of the metal nitride film located at the bottom to the side wall of the bottom A semiconductor device manufacturing apparatus characterized by the above. A manufacturing apparatus of a semiconductor device according to claim 7,
The first film forming unit includes:
The metal nitride film is coated on the substrate by a reactive sputtering method using a target composed of the constituent element of the metal film, and a bias voltage is applied to the substrate to be positioned at the bottom of the recess. A chamber for sputtering a part of
The controller is
When the target is sputtered to coat the metal nitride film, a bias voltage is applied to the substrate to sputter a part of the metal nitride film located at the bottom of the recess;
An apparatus for manufacturing a semiconductor device. A semiconductor device manufacturing apparatus according to claim 7 or 8,
The first film forming unit includes:
The metal nitride film is formed by a reactive sputtering method using a target composed of the constituent element of the metal film, and a part of the metal nitride film located at the bottom of the concave portion by applying a bias voltage to the substrate A chamber for sputtering,
The controller is
When the target is sputtered to coat the metal nitride film, a bias voltage is applied to the substrate to sputter part of the metal nitride film located at the bottom of the recess, and the metal nitride located at the bottom Making the membrane substantially flat,
An apparatus for manufacturing a semiconductor device. A semiconductor device manufacturing apparatus according to any one of claims 7 to 9,
An annealing portion for raising the temperature of the substrate to a predetermined temperature,
The transport unit transports the substrate to the annealing unit;
The control unit drives the transport unit to transport the substrate on which the first aluminum film is formed to the annealing unit, and drives the annealing unit to raise the temperature of the substrate to the predetermined temperature. Annealing the first aluminum film;
An apparatus for manufacturing a semiconductor device. It is a manufacturing apparatus of the semiconductor device according to any one of claims 7 to 10,
A third film-forming part for covering the substrate with a second aluminum film using a PVD method;
The transport unit transports the substrate to the third film forming unit;
The control unit drives the transport unit to transport the substrate on which the first aluminum film is formed to the third film forming unit, and drives the third film forming unit to drive the first aluminum film. Further laminating the second aluminum film on the top,
An apparatus for manufacturing a semiconductor device. It is a manufacturing apparatus of the semiconductor device according to any one of claims 7-11,
The first film forming unit is equipped with a target made of any one of titanium, tantalum, nickel, and cobalt,
An apparatus for manufacturing a semiconductor device.

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