Patent ID: 12227841

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one of ordinary skill in the art that the present disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, systems, and components have not been described in detail so as not to unnecessarily obscure aspects of the various embodiments.

Hereinafter, a non-limiting exemplary embodiment of the present disclosure will be described with reference to the accompanying drawings. Throughout the accompanying drawings, the same or corresponding members or parts will be denoted by the same or corresponding reference numerals, and the redundant description thereof will be omitted.

[Ruthenium Film Forming Method]

An example of a method for forming a ruthenium (Ru) film according to one embodiment will be described.FIGS.1A to1Fare sectional process views showing an example of a ruthenium film forming method according to one embodiment.

The ruthenium film forming method shown inFIGS.1A to1Fincludes a step of causing chlorine to be adsorbed to an upper portion of a recess at a higher density than to a lower portion of the recess by supplying a chlorine-containing gas to a substrate including an insulating film and having the recess, and a step of forming a ruthenium film in the recess by supplying a Ru-containing precursor to the recess to which the chlorine is adsorbed. The details will be described below.

First, as shown inFIG.1A, a substrate100having an insulating film102formed on a metal layer101is prepared. The substrate100is, for example, a semiconductor wafer such as a silicon wafer or the like. The metal layer101is, for example, a wiring material such as a tungsten film or the like. The insulating film102is, for example, a laminated film of a silicon nitride film102aand a silicon oxide film102b. The silicon nitride film102ais, for example, an etching stopper layer. The silicon oxide film102bis, for example, an interlayer insulating film. The insulating film102may be a single layer film such as a silicon nitride film or a silicon oxide film. A recess103such as a trench or a hole is formed in the insulating film102. The metal layer101is exposed on a bottom surface103cof the recess103. When a natural oxide film or the like is formed on the exposed surface of the metal layer101, a cleaning step of removing the natural oxide film or the like may be performed. The cleaning step is, for example, a step of removing the oxide film formed on the bottom surface103cof the recess103(the exposed surface of the metal layer101) by supplying a chlorine-containing gas to the bottom surface103cof the recess103. For example, a tungsten oxide film may be removed by alternately supplying a chlorine (Cl2) gas and plasma using an argon (Ar) gas. When the processing temperature is high (e.g., 200 degrees C. or higher), the tungsten oxide film may be removed by supplying only the Cl2gas without using the plasma of the Ar gas. In addition, the tungsten oxide film may be physically removed by performing sputtering with the plasma of the Ar gas.

Subsequently, as shown inFIG.1B, a chlorine-containing gas is supplied to the substrate100so that chlorine104is adsorbed to the upper portion of the recess103at a higher density than to the lower portion of the recess103. For example, the chlorine104is adsorbed to an upper surface103aand the upper portion of a side surface103bof the recess103. The chlorine104is not adsorbed to the lower portion of the side surface103band the bottom surface103cof the recess103. The method of causing the chlorine104to be adsorbed to the upper portion of the recess103at a higher density than to the lower portion of the recess103is not particularly limited, and may be, for example, a method of supplying a chlorine-containing gas into a depressurized processing container by activating the chlorine-containing gas with plasma. Furthermore, the method may be, for example, a method of adjusting a process condition such as a pressure, a temperature, a gas flow rate, and the like in a processing container without activating a chlorine-containing gas with plasma. The chlorine-containing gas is, for example, a Cl2gas.

Subsequently, as shown inFIG.1C, a ruthenium film105is formed in the recess103by supplying a Ru-containing precursor to the recess103to which the chlorine104is adsorbed. At this time, the chlorine104serves as an adsorption inhibition layer that inhibits adsorption of the Ru-containing precursor. Therefore, the ruthenium film105is hard to be formed on the surface of the recess103to which the chlorine104is adsorbed. For that reason, at the initial stage of film formation, the ruthenium film105is thickly formed on the lower portion of the side surface103band the bottom surface103cof the recess103to which the chlorine104is not adsorbed. On the other hand, the ruthenium film105is scarcely formed on the upper surface103aand the upper portion of the side surface103bof the recess103to which the chlorine104is adsorbed, or is formed more thinly on the upper surface103aand the upper portion of the side surface103bof the recess103than on the lower portion of the side surface103band the bottom surface103cof the recess103. As a result, the ruthenium film105is formed in a V shape in the recess103. The Ru-containing precursor is, for example, triruthenium dodecacarbonyl (Ru3(CO)12), η4-2,3-dimethylbutadiene ruthenium tricarbonyl (Ru(DMBD)(CO)3), (2,4-dimethylpentadienyl)(ethylcyclopentadienyl) ruthenium (Ru(DMPD)(EtCp)), bis(2,4-dimethylpentadienyl) ruthenium (Ru(DMPD)2), 4-dimethylpentadienyl (methylcyclopentadienyl) ruthenium (Ru(DMPD)(MeCp), bis (cyclopentadienyl) ruthenium (Ru(C5H5)2), cis-dicarbonyl bis (5-methylhexane-2,4-dionate) ruthenium (II), or the like.

Subsequently, as shown inFIGS.1D and1E, the ruthenium film105is embedded in the recess103by continuously supplying the Ru-containing precursor to the recess103. At this time, since the ruthenium film105is formed in a V shape in the recess103at the initial stage of film formation, bottom-up film formation is performed in which film formation gradually progresses upward from the bottom surface103cof the recess103. As a result, as shown inFIG.1F, the ruthenium film105in which generation of voids, seams, and the like is suppressed can be formed in the recess103. That is to say, the ruthenium film105having good embedding characteristics can be formed in the recess103.

Another example of the ruthenium film forming method according to one embodiment will be described.FIGS.2A to2Iare sectional process views showing another example of the ruthenium film forming method according to one embodiment.

The ruthenium film forming method shown inFIGS.2A to2Iis a method of forming a ruthenium film in a recess by alternately repeating the step of causing the chlorine to be adsorbed and the step of forming the ruthenium film, which are adopted in the ruthenium film forming method shown inFIGS.1A to1F. The details will be described below.

First, as shown inFIG.2A, a substrate200having an insulating film202formed on a metal layer201is prepared. The substrate200is, for example, a semiconductor wafer such as a silicon wafer or the like. The metal layer201is, for example, a wiring material such as a tungsten film. The insulating film202is, for example, a laminated film of a silicon nitride film202aand a silicon oxide film202b. The silicon nitride film202ais, for example, an etching stopper layer. The silicon oxide film202bis, for example, an interlayer insulating film. The insulating film202may be, for example, a single layer film such as a silicon nitride film or a silicon oxide film. A recess203such as a trench or a hole is formed in the insulating film202. The metal layer201is exposed at a bottom surface203cof the recess203. When a natural oxide film or the like is formed on the exposed surface of the metal layer201, a cleaning step of removing the natural oxide film or the like may be performed. The cleaning step is, for example, a step of supplying a chlorine-containing gas to the bottom surface203cof the recess203to remove the oxide film formed on the bottom surface203cof the recess203(the exposed surface of the metal layer201). For example, a tungsten oxide film may be removed by alternately supplying a Cl2gas and plasma of an Ar gas. When the processing temperature is high (e.g., 200 degrees C. or higher), the tungsten oxide film may be removed by supplying only the Cl2gas without using the plasma of the Ar gas. In addition, the tungsten oxide film may be physically removed by performing sputtering with the plasma of the Ar gas.

Subsequently, as shown inFIG.2B, a chlorine-containing gas is supplied to the substrate200so that chlorine204is adsorbed to the upper portion of the recess203at a higher density than to the lower portion of the recess203. For example, the chlorine204is adsorbed to an upper surface203aand the upper portion of a side surface203bof the recess203, and the chlorine204is not adsorbed to the lower portion of the side surface203band the bottom surface203cof the recess203. The method of causing the chlorine204to be adsorbed to the upper portion of the recess103at a higher density than to the lower portion of the recess203is not particularly limited, and may be, for example, a method of supplying a chlorine-containing gas into a depressurized processing container by activating the chlorine-containing gas with plasma. Furthermore, the method may be, for example, a method of adjusting a process condition such as a pressure, a temperature, a gas flow rate, and the like in a processing container without activating a chlorine-containing gas with plasma. The chlorine-containing gas is, for example, a Cl2gas.

Subsequently, as shown inFIG.2C, a ruthenium film205is formed in the recess203by supplying a Ru-containing precursor to the recess203to which the chlorine204is adsorbed. At this time, the chlorine204serves as an adsorption inhibition layer that inhibits adsorption of the Ru-containing precursor. Therefore, it is hard for the ruthenium film205to be formed on the surface of the recess203to which the chlorine104is adsorbed. For that reason, at the initial stage of film formation, the ruthenium film205is thickly formed on the lower portion of the side surface203band the bottom surface203cof the recess203to which the chlorine204is not adsorbed. On the other hand, the ruthenium film205is scarcely formed on the upper surface203aand the upper portion of the side surface203bof the recess203to which the chlorine204is adsorbed, or is formed more thinly on the upper surface203aand the upper portion of the side surface203bof the recess203than on the lower portion of the side surface203band the bottom surface203cof the recess203. As a result, the ruthenium film205is formed in a V shape in the recess203. The Ru-containing precursor may be, for example, the same as the Ru-containing precursor used in the ruthenium film forming method shown inFIGS.1A to1Fdescribed above.

Subsequently, as shown inFIG.2D, a chlorine-containing gas is supplied to the substrate200so that chlorine204is adsorbed to the upper portion of the recess203at a higher density than to the lower portion of the recess203. For example, the chlorine204is adsorbed to the upper surface203aand the upper portion of the side surface203bof the recess203, and the chlorine204is not adsorbed to the lower portion of the side surface203band the bottom surface203cof the recess203. The method of causing the chlorine204to be adsorbed to the upper portion of the recess103at a higher density than to the lower portion of the recess203is not particularly limited, and may be, for example, a method of supplying a chlorine-containing gas into a depressurized processing container by activating the chlorine-containing gas with plasma. Furthermore, the method may be, for example, a method of adjusting a process condition such as a pressure, a temperature, a gas flow rate, and the like in a processing container without activating a chlorine-containing gas with plasma. The chlorine-containing gas is, for example, a Cl2gas.

Subsequently, as shown inFIG.2E, a ruthenium film205is formed in the recess203by supplying a Ru-containing precursor to the recess203to which the chlorine204is adsorbed. At this time, the chlorine204serves as an adsorption inhibition layer that inhibits adsorption of the Ru-containing precursor. Therefore, it is hard for the ruthenium film205to be formed on the surface of the recess203to which the chlorine104is adsorbed. For that reason, a ruthenium film205is thickly formed on the surface of the ruthenium film205formed on the lower portion of the side surface203band the bottom surface203cof the recess203to which the chlorine204is not adsorbed. On the other hand, the ruthenium film205is scarcely formed on the upper surface203aand the upper portion of the side surface203bof the recess203to which the chlorine204is adsorbed, or is formed more thinly on the upper surface203aand the upper portion of the side surface203bof the recess203than on the surface of the ruthenium film205formed on the lower portion of the side surface203band the bottom surface203cof the recess203. As a result, the ruthenium film205is formed in a V shape in the recess203. The Ru-containing precursor may be, for example, the same as the Ru-containing precursor used in the ruthenium film forming method shown inFIGS.1A to1Fdescribed above.

Subsequently, as shown inFIGS.2F to2I, the adsorption of the chlorine204and the formation of the ruthenium film205are alternately repeated to embed the ruthenium film205in the recess203. At this time, since the ruthenium film205is embedded in the recess203by alternately repeating the adsorption of the chlorine and the formation of the ruthenium film205, the bottom-up film formation in which film formation gradually progresses upward from the bottom surface203cof the recess203is promoted. As a result, even when the recess203has a high aspect ratio (ratio of the depth to the opening width of the recess203), it is possible to form the ruthenium film205in which generation of voids, seams and the like is suppressed. That is, the ruthenium film205having good embedding characteristics can be formed in the recess203having a high aspect ratio.

[Substrate Processing System]

An example of a substrate processing system that realizes the ruthenium film forming method according to one embodiment will be described.FIG.3is a schematic diagram showing a configuration example of the substrate processing system.

A substrate processing system1includes processing chambers11to14, a vacuum transfer chamber20, load lock chambers31and32, an atmospheric transfer chamber40, load ports51to53, gate valves61to68, and a control device70.

The processing chamber11includes a stage11aon which a semiconductor wafer (hereinafter referred to as “wafer W”) is mounted, and is connected to the vacuum transfer chamber20via the gate valve61. Similarly, the processing chamber12includes a stage12aon which the wafer W is mounted, and is connected to the vacuum transfer chamber20via the gate valve62. The processing chamber13includes a stage13aon which the wafer W is mounted, and is connected to the vacuum transfer chamber20via the gate valve63. The processing chamber14includes a stage14aon which the wafer W is mounted, and is connected to the vacuum transfer chamber20via the gate valve64. The interiors of the processing chambers11to14are depressurized to a predetermined vacuum atmosphere, and the wafer W is subjected to desired processes (an etching process, a film-forming process, a cleaning process, an ashing process, and the like) inside the processing chambers11to14. Operations of the respective components for performing processes in the processing chambers11to14are controlled by the control device70.

The interior of the vacuum transfer chamber20is depressurized to a predetermined vacuum atmosphere. A transfer mechanism21is provided in the vacuum transfer chamber20. The transfer mechanism21transfers the wafer W to and from the processing chambers11to14and the load lock chambers31and32. Operation of the transfer mechanism21is controlled by the control device70.

The load lock chamber31includes a stage31aon which the wafer W is mounted. The load lock chamber31is connected to the vacuum transfer chamber20via the gate valve65and is connected to the atmosphere transfer chamber40via the gate valve67. Similarly, the load lock chamber32includes a stage32aon which the wafer W is mounted. The load lock chamber32is connected to the vacuum transfer chamber20via the gate valve66and is connected to the atmosphere transfer chamber40via the gate valve68. The interiors of the load lock chambers31and32may be switched between atmospheric atmosphere and a vacuum atmosphere. The control device70controls the switching between the vacuum atmosphere and atmospheric atmosphere in the load lock chambers31and32.

The interior of the atmosphere transfer chamber40is kept in atmospheric atmosphere. For example, a down-flow of a clean air is formed inside the atmosphere transfer chamber40. A transfer mechanism41is provided in the atmosphere transfer chamber40. The transfer mechanism41transfers the wafer W to and from the load lock chambers31and32and carriers C in the load ports51to53. Operation of the transfer mechanism41is controlled by the control device70.

The load ports51to53are provided on a long side wall surface of the atmosphere transfer chamber40. A carrier C containing wafers W or an empty carrier C is attached to the load ports51to53. The carrier C is, for example, a front opening unified pod (FOUP).

The gate valves61to68are configured to be openable and closable. The opening and closing of the gate valves61to68are controlled by the control device70.

The control device70controls the substrate processing system1as a whole by performing the operations of the processing chambers11to14, the operations of the transfer mechanisms21and41, the opening and closing of the gate valves61to68, and the switching of the vacuum atmosphere and atmospheric atmosphere in the load lock chambers31and32.

Next, an example of operation of the substrate processing system will be described. For example, the control device70opens the gate valve67and controls the transfer mechanism41to transfer, for example, the wafer W accommodated in the carrier C of the load port51to the stage31aof the load lock chamber31. The control device70closes the gate valve67and keeps the interior of the load lock chamber31in a vacuum atmosphere.

The control device70opens the gate valves61and65and controls the transfer mechanism21to transfer the wafer W in the load lock chamber31to the stage11aof the processing chamber11. The control device70closes the gate valves61and65and operates the processing chamber11. As a result, the wafer W is subjected to a predetermined process (e.g., the aforementioned process of the step of causing chlorine to be adsorbed) in the processing chamber11.

Subsequently, the control device70opens the gate valves61and63and controls the transfer mechanism21to transfer the wafer W processed in the processing chamber11to the stage13aof the processing chamber13. The control device70closes the gate valves61and63and operates the processing chamber13. As a result, the wafer W is subjected to a predetermined process (e.g., the aforementioned process of the step of forming a ruthenium film) in the processing chamber13.

The control device70may transfer the wafer W processed in the processing chamber11to the stage14aof the processing chamber14capable of performing the same process as in the processing chamber13. In one embodiment, the wafer W in the processing chamber11is transferred to the processing chamber13or the processing chamber14depending on the operating states of the processing chamber13and the processing chamber14. As a result, the control device70may use the processing chamber13and the processing chamber14to perform a predetermined process (e.g., the aforementioned process of the step of forming a ruthenium film) on a plurality of wafers W in parallel. This makes it possible to enhance the productivity.

The control device70controls the transfer mechanism21to transfer the wafer W processed in the processing chamber13or the processing chamber14to the stage31aof the load lock chamber31or the stage32aof the load lock chamber32. The control device70keeps the interior of the load lock chamber31or the load lock chamber32in atmospheric atmosphere. The control device70opens the gate valve67or the gate valve68and controls the transfer mechanism41to transfer the wafer W in the load lock chamber32to, for example, the carrier C in the load port53and store the wafer W in the carrier C.

As described above, according to the substrate processing system1shown inFIG.3, while the wafer W is processed by each processing chamber, the wafer W can be subjected to a predetermined process without exposing the wafer W to the atmosphere, i.e., without breaking the vacuum.

[Processing Apparatus]

A configuration example of a processing apparatus400that realizes the processing chamber used for the process of the step of causing the chlorine to be adsorbed in the ruthenium film forming method according to one embodiment will be described.FIG.4is a schematic diagram showing an example of the processing apparatus400that executes the process of the step of causing the chlorine to be adsorbed.

The processing apparatus400shown inFIG.4is, for example, an apparatus that performs a step of causing chlorine to be adsorbed. In the processing apparatus400, for example, a chlorine-containing gas is supplied to perform a process of causing chlorine to be adsorbed to the wafer W. Hereinafter, the processing apparatus400used in the processing chamber11will be described by way of example.

The processing apparatus400includes a processing container410, a stage420, a shower head430, an exhauster440, a gas supply mechanism450, and a control device460.

The processing container410is made of metal such as aluminum or the like and has a substantially cylindrical shape.

A loading and unloading port411for loading and unloading the wafer W is formed on a sidewall of the processing container410. The loading and unloading port411is opened or closed by a gate valve412. An annular exhaust duct413having a rectangular cross section is provided on a main body of the processing container410. A slit413ais formed in the exhaust duct413along the inner circumferential surface thereof. An exhaust port413bis formed on the outer wall of the exhaust duct413. A ceiling wall414is provided on the upper surface of the exhaust duct413so as to close the upper opening of the processing container410. A gap between the exhaust duct413and the ceiling wall414is hermetically sealed by a seal ring415.

The stage420is a member that horizontally supports the wafer W in the processing container410, and is illustrated as the stage11ainFIG.3. The stage420is formed in a disk shape having a size corresponding to the wafer W and is supported by a support423. The stage420is made of ceramic material such as aluminum nitride (AlN) or the like, or a metallic material such as aluminum, nickel alloy, or the like. A heater421for heating the wafer W and an electrode429are embedded in the stage420. The heater421is supplied with an electric power from a heater power source (not shown) to generate heat. The output of the heater421is controlled by a temperature signal of a thermocouple (not shown) provided near the upper surface of the stage420, whereby the wafer W is controlled to a predetermined temperature.

A first high frequency power source444is connected to the electrode429via a matcher443. The matcher443matches a load impedance with an internal impedance of the first high frequency power source444. The first high frequency power source444applies an electric power of a predetermined frequency to the stage420via the electrode429. For example, the first high frequency power source444applies high frequency power of 13.56 MHz to the stage420via the electrode429. The high frequency power is not limited to 13.56 MHz. For example, high frequency power of 450 KHz, 2 MHz, 27 MHz, 60 MHz, 100 MHz, or the like may be appropriately used. In this way, the stage420also functions as a lower electrode.

Furthermore, the electrode429is connected to an adsorption power source449via an ON/OFF switch448arranged outside the processing container410, and also functions as an electrode for attracting the wafer W toward the stage420.

Furthermore, the shower head430is connected to a second high frequency power source446via a matcher445. The matcher445matches a load impedance with an internal impedance of the second high frequency power source446. The second high frequency power source446applies an electric power of a predetermined frequency to the shower head430. For example, the second high frequency power supply446applies high frequency power of 13.56 MHz to the shower head430. The high frequency power is not limited to 13.56 MHz. For example, high frequency power of 450 KHz, 2 MHz, 27 MHz, 60 MHz, 100 MHz, or the like may be appropriately used. In this way, the shower head430also functions as an upper electrode.

In the stage420, a cover member422made of ceramics such as alumina or the like is provided so as to cover the outer peripheral region of the upper surface and the side surface of the stage420. An adjustment mechanism447that adjusts a gap G between the upper electrode and the lower electrode is provided on the bottom surface of the stage420. The adjustment mechanism447includes the support423and an elevating mechanism424. The support423supports the stage420at the center of the bottom surface of the stage420. In addition, the support423extends through a hole formed in the bottom wall of the processing container410and extends to below the processing container410. The lower end of the support423is connected to the elevating mechanism424. The stage420is moved up and down by the elevating mechanism424via the support423. The adjustment mechanism447may move the elevating mechanism424up and down between a processing position indicated by a solid line inFIG.4and a delivery position located below the processing position as indicated by a two-dot chain line so that the wafer W can be transferred. This makes it possible to load and unload the wafer W.

A flange425is attached to the support423below the processing container410. A bellows426that separates the atmosphere in the processing container410from the ambient air and expands and contracts as the stage420moves up and down is provided between the bottom surface of the processing container410and the flange425.

In the vicinity of the bottom surface of the processing container410, three lift pins427(only two of which are shown) are provided so as to protrude upward from a lift plate427a. The lift pins427are raised and lowered via the lift plate427aby a lift mechanism428provided below the processing container410.

The lift pins427are inserted into through-holes420aprovided in the stage420located at the delivery position and can protrude or retract with respect to the upper surface of the stage420. By raising and lowering the lift pins427, the wafer W is delivered between the transfer mechanism (not shown) and the stage420.

The shower head430supplies a process gas into the processing container410in a shower shape. The shower head430is made of metal and is provided so as to face the stage420. The shower head430has a diameter substantially equal to that of the stage420. The shower head430includes a main body431fixed to the ceiling wall414of the processing container410, and a shower plate432connected to the underside of the main body431. A gas diffusion space433is formed between the main body431and the shower plate432, and a gas introduction hole436loading to the gas diffusion space433is provided so as to pass through the ceiling wall414of the processing container410and the center of the main body431. An annular protrusion434that protrudes downward is formed at the peripheral edge portion of the shower plate432. Gas discharge holes435are formed on the inner flat surface of the annular protrusion434. When the stage420is in the processing position, a processing space438is formed between the stage420and the shower plate432, and the upper surface of the cover member422comes close to the annular protrusion434to form an annular gap439.

The exhauster440evacuates the interior of the processing container410. The exhauster440includes an exhaust pipe441connected to the exhaust port413b, and an exhaust mechanism442connected to the exhaust pipe441and provided with a vacuum pump, a pressure control valve, and the like. At the time of processing, the gas in the processing container410is moved to the exhaust duct413through the slit413aand is exhausted from the exhaust duct413through the exhaust pipe441by the exhaust mechanism442.

The gas supply mechanism450is connected to the gas introduction hole436of the shower head430via a gas supply line437. The gas supply mechanism450is connected to gas supply sources of various gases used in the process of the step of causing the chlorine to be adsorbed, through gas supply lines, respectively. For example, the gas supply mechanism450is connected to gas supply sources for supplying various gases such as a Cl2gas, an H2gas, a rare gas, and the like, via gas supply lines, respectively.

Each gas supply line is appropriately branched according to the process of the step of causing the chlorine to be adsorbed. An opening and closing valve and a flow rate controller are provided on each gas supply line. The gas supply mechanism450is capable of controlling the flow rates of various gases by controlling the opening and closing valve and the flow rate controller provided in each gas supply line. The gas supply mechanism450supplies each of various gases including a Cl2gas into the processing container410via the gas supply line437and the shower head430during the process of the step of causing the chlorine to be adsorbed.

Operation of the processing apparatus400configured as described above is generally controlled by the control device460. The control device460is, for example, a computer, and includes a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), an auxiliary memory device, and the like. The CPU operates based on a program stored in the ROM or the auxiliary memory device or a process condition of the process of the step of causing the chlorine to be adsorbed, and controls the operation of the apparatus as a whole. For example, the control device460controls the supply operation of various gases from the gas supply mechanism450, the elevating operation of the elevating mechanism424, the evacuating operation of the interior of the processing container410by the exhaust mechanism442, and the electric powers supplied from the first high frequency power source444and the second high frequency power source446. The computer-readable program necessary for control may be stored in a storage medium. The storage medium is, for example, a flexible disk, a compact disc (CD), a CD-ROM, a hard disk, a flash memory, a DVD, or the like. The control device460may be provided independently of the control device70(seeFIG.3), or the control device70may also serve as the control device460.

An example of the operation of the processing apparatus400will be described. At the time of startup, the interior of the processing chamber11is kept in a vacuum atmosphere by the exhauster440. In addition, the stage420is moved to the delivery position.

The control device460opens the gate valve412. At this time, the wafer W is placed on the lift pins427by the external transfer mechanism21. When the transfer mechanism21comes out of the loading and unloading port411, the control device460closes the gate valve412.

The control device460controls the elevating mechanism424to move the stage420to the processing position. At this time, as the stage420moves up, the wafer W placed on the lift pins427is mounted on the mounting surface of the stage420.

At the processing position, the control device460operates the heater421and turns on the ON/OFF switch448to attract the wafer W to the stage420. Furthermore, the control device460controls the gas supply mechanism450to supply a process gas such as a chlorine-containing gas or the like, or a carrier gas, into the processing chamber11from the shower head430. As a result, a predetermined process such as the process of the step of causing the chlorine to be adsorbed to the wafer W is performed. The gas remaining after the process passes through a flow path on the upper surface side of the cover member422and is exhausted by the exhaust mechanism442via the exhaust pipe441.

At this time, the control device460controls the first high frequency power source444and the matcher443to apply an electric power of a predetermined frequency to the stage420. Furthermore, the control device460controls the second high frequency power source446and the matcher445to apply an electric power of a predetermined frequency to the shower head430.

When the predetermined process is completed, the control device460turns off the ON/OFF switch448to release the attraction of the wafer W to the stage420, and controls the elevating mechanism424to move the stage420to the delivery position. At this time, head portions of the lift pins427protrude from the mounting surface of the stage420to lift the wafer W from the mounting surface of the stage420.

The control device460opens the gate valve412. At this time, the wafer W placed on the lift pins427is unloaded by the external transfer mechanism21. When the transfer mechanism21comes out of the loading and unloading port411, the control device460closes the gate valve412.

As described above, according to the processing apparatus400shown inFIG.4, it is possible to perform a predetermined process such as the process of the step of causing the chlorine to be adsorbed to the wafer W.

A suitable process condition of the step of causing the chlorine to be adsorbed, which is performed using the processing apparatus400, is as follows.

Chlorine-containing gas: Cl2gas (10 to 1000 sccm)Pressure in the processing container410: 1 to 100 mTorr (0.13 to 13 Pa)Wafer temperature: 60 to 300 degrees C.Electric power of the second high frequency power source446: 50 to 500 W

Next, a configuration example of a processing apparatus500that realizes the processing chamber used in the process of the step of forming the ruthenium film in the ruthenium film forming method according to one embodiment will be described.FIG.5is a schematic diagram showing an example of the processing apparatus500that performs the process of the step of forming the ruthenium film.

The processing apparatus500shown inFIG.5is a chemical vapor deposition (CVD) apparatus and is, for example, an apparatus for performing the step of forming the ruthenium film. In the processing apparatus500, for example, a ruthenium-containing precursor is supplied to perform the step of forming the ruthenium film on the wafer W. Hereinafter, the processing apparatus500used in the processing chamber13will be described by way of example.

A main body container501is a bottom-closed container having an opening on the upper side thereof. A support502supports a gas discharge mechanism503. Furthermore, the support502closes the upper opening of the main body container501so that the main body container501is hermetically sealed to form the processing chamber13(also seeFIG.3). A gas supplier504supplies a process gas such as a ruthenium-containing gas or the like, or a carrier gas, to the gas discharge mechanism503via a supply pipe502apenetrating the support502. The ruthenium-containing gas or the carrier gas supplied from the gas supplier504is supplied from the gas discharge mechanism503into the processing chamber13.

A stage505is a member on which the wafer W is mounted, and is illustrated as the stage13ainFIG.3. Inside the stage505, a heater506for heating the wafer W is provided. Furthermore, the stage505includes a support505awhich extends downward from the center of the lower surface of the stage505and which has one end penetrating the bottom portion of the main body container501and supported by an elevating mechanism via an elevating plate509. Furthermore, the stage505is fixed on a temperature control jacket508, which is a temperature control member, via a heat insulating ring507. The temperature control jacket508includes a plate portion for fixing the stage505, a shaft portion extending downward from the plate portion and configured to cover the support505a, and a hole portion extending through the shaft portion from the plate portion.

The shaft portion of the temperature control jacket508penetrates the bottom portion of the main body container501. The lower end portion of the temperature control jacket508is supported by an elevating mechanism510via the elevating plate509arranged below the main body container501. A bellows511is provided between the bottom portion of the main body container501and the elevating plate509. The airtightness inside the main body container501is maintained even when the elevating plate509moves up and down.

When the elevating mechanism510raises and lowers the elevating plate509, the stage505moves up and down between a processing position (seeFIG.5) where the wafer W is processed and a delivery position (not shown) where the wafer W is delivered to and from the external transfer mechanism21(seeFIG.3) via a loading and unloading port501a.

Lift pins512support the lower surface of the wafer W and lift the wafer W from the mounting surface of the stage505when the wafer W is delivered to and from the external transfer mechanism21(seeFIG.3). Each of the lift pins512includes a shaft portion and a head portion having a diameter larger than that of the shaft portion. Through-holes through which the shaft portions of the lift pins512are inserted are formed in the stage505and the plate portion of the temperature control jacket508. In addition, groove portions for accommodating the head portions of the lift pins512are formed on the mounting surface side of the stage505. A contact member513is arranged below the lift pins512.

In a state in which the stage505moved to the processing position for the wafer W (seeFIG.5), the head portions of the lift pins512are accommodated in the groove portions, and the wafer W is mounted on the mounting surface of the stage505. Furthermore, the head portions of the lift pins512are locked in the groove portions, the shaft portions of the lift pins512penetrate the stage505and the plate portion of the temperature control jacket508, and the lower ends of the shaft portions of the lift pins512protrude from the plate portion of the temperature control jacket508. On the other hand, in a state where the stage505is moved to the delivery position (not shown) for the wafer W, the lower ends of the lift pins512make contact with the contact member513, and the head portions of the lift pins512protrude from the mounting surface of the stage505. As a result, the head portions of the lift pins512support the lower surface of the wafer W and lift the wafer W from the mounting surface of the stage505.

An annular member514is arranged above the stage505. In a state in which the stage505is moved to the processing position for the wafer W (seeFIG.5), the annular member514makes contact with the outer peripheral portion of the upper surface of the wafer W, and the weight of the annular member514causes the wafer W to be pressed against the mounting surface of the stage505. On the other hand, in a state in which the stage505is moved to the delivery position (not shown) for the wafer W, the annular member514is locked by a locking part (not shown) at a position above the loading and unloading port501a. As a result, the delivery of the wafer W by the transfer mechanism21(seeFIG.3) is not hindered.

A chiller unit515circulates a coolant, for example, cooling water, through a flow path508aformed in the plate portion of the temperature control jacket508via pipes515aand515b.

A heat transfer gas supplier516supplies a heat transfer gas such as an He gas or the like to between the back surface of the wafer W mounted on the stage505and the mounting surface of the stage505via a pipe516a.

A purge gas supplier517supplies a purge gas to a pipe517a, a gap between the support505aand the hole portion of the temperature control jacket508, a flow path formed between the stage505and the heat insulating ring507to extend radially outward, and a vertical flow path formed in the outer peripheral portion of the stage505. The purge gas such as, for example, a carbon monoxide (CO) gas or the like is supplied to between the lower surface of the annular member514and the upper surface of the stage505through these flow paths. This prevents the process gas from flowing into a space between the lower surface of the annular member514and the upper surface of the stage505, thereby preventing film formation on the lower surface of the annular member514or on the upper surface of the outer peripheral portion of the stage505.

On the side wall of the main body container501, the loading and unloading port501afor loading and unloading the wafer W and a gate valve518for opening and closing the loading and unloading port501aare provided. The gate valve518is shown as the gate valve63inFIG.3.

An exhauster519including a vacuum pump and the like is connected to the lower side wall of the main body container501via an exhaust pipe501b. The interior of the main body container501is evacuated by the exhauster519, and the interior of the processing chamber13is set to and maintained in a predetermined vacuum atmosphere (e.g., 1.33 Pa).

A control device520controls the gas supplier504, the heater506, the elevating mechanism510, the chiller unit515, the heat transfer gas supplier516, the purge gas supplier517, the gate valve518, the exhauster519, and the like, thereby controlling the operation of the processing apparatus500. The control device520may be provided independently of the control device70(seeFIG.3). The control device70may also serve as the control device520.

An example of operation of the processing apparatus500will be described. At the time of startup, the interior of the processing chamber13is kept in a vacuum atmosphere by the exhauster519. The stage505is moved to the delivery position.

The control device520opens the gate valve518. At this time, the wafer W is placed on the lift pins512by the external transfer mechanism21. When the transfer mechanism21comes out of the loading and unloading port501a, the control device520closes the gate valve518.

The control device520controls the elevating mechanism510to move the stage505to the processing position. At this time, as the stage505moves up, the wafer W placed on the lift pins512is mounted on the mounting surface of the stage505. Furthermore, the annular member514makes contact with the outer peripheral portion of the upper surface of the wafer W. and the weight of the annular member514causes the wafer W to be pressed against the mounting surface of the stage505.

At the processing position, the control device520operates the heater506and controls the gas supplier504to supply a process gas such as a ruthenium-containing gas or the like, or a carrier gas, from the gas discharge mechanism503into the processing chamber12. As a result, a predetermined process such as the process of the step of forming the ruthenium film on the wafer W is performed. The gas remaining after the process passes through a flow path on the upper surface side of the annular member514and is exhausted by the exhauster519via the exhaust pipe501b.

At this time, the control device520controls the heat transfer gas supplier516to supply a heat transfer gas between the back surface of the wafer W mounted on the stage505and the mounting surface of the stage505. Furthermore, the control device520controls the purge gas supplier517to supply a purge gas to between the lower surface of the annular member514and the upper surface of the stage505. The purge gas passes through a flow path on the lower surface side of the annular member514and is exhausted by the exhauster519via the exhaust pipe501b.

When the predetermined process is completed, the control device520controls the elevating mechanism510to move the stage505to the delivery position. At this time, as the stage505moves down, the annular member514is locked by the locking portion (not shown). Furthermore, when the lower ends of the lift pins512makes contact with the contact member513, the head portions of the lift pins512protrude from the mounting surface of the stage505and lift the wafer W from the mounting surface of the stage505.

The control device520opens the gate valve518. At this time, the wafer W placed on the lift pins512is unloaded by the external transfer mechanism21. When the transfer mechanism21comes out of the loading and unloading port501a, the control device520closes the gate valve518.

As described above, according to the processing apparatus500shown inFIG.5, it is possible to perform a predetermined process such as the process of the step of forming the ruthenium film on the wafer W.

Although the processing apparatus400having the processing chamber11and the processing apparatus500having the processing chamber13have been described above, a processing apparatus having the processing chamber12and a processing apparatus having the processing chamber14may have the same configuration as that of any one of the above-described processing apparatuses, or may have a different configuration from that of any one of the above-described processing apparatuses. The configuration of the processing apparatus is appropriately applicable from the viewpoint of the operating rate or the productivity.

Example

Next, an example conducted to verify the adsorption inhibition effect of chlorine against the Ru-containing precursor will be described.

In the example, first, two wafers were prepared in which a TiN film602and a tungsten film603are stacked in the named order on a silicon base601.

Subsequently, one of the prepared wafers was subjected to a process of a step of causing chlorine to be adsorbed in the processing chamber11, and then subjected to a process of a step of forming a ruthenium film604in the processing chamber13. Furthermore, the other of the prepared wafers was subjected to a process of a step of forming a ruthenium film604in the processing chamber13without being subjected to a process of a step of causing chlorine to be adsorbed in the processing chamber11. The process conditions of the process of the step of forming the ruthenium film604, which is performed in the processing chamber13on the one wafer and the other wafer, are the same. The process conditions of the step of causing the chlorine to be adsorbed and the step of forming the ruthenium film604are as follows.

(Step of Causing the Chlorine to be Adsorbed)

Chlorine-containing gas: Cl2gas (240 sccm)Processing pressure: 30 mTorr (4 Pa)Wafer temperature: 60 degrees C.
(Step of Forming the Ruthenium Film604)Processing pressure: 20 mTorr (2.7 Pa)Wafer temperature: 155 degrees C.

Then, the film thickness of the ruthenium film604formed on the tungsten film603was evaluated by observing the cross sections of the two wafers using a transmission electron microscope (TEM).

FIGS.6A and6Bare views for explaining an adsorption inhibition effect of chlorine and are TEM images of the cross section of the ruthenium film604formed on the tungsten film603.FIG.6Ashows the cross section of the wafer that has been subjected to the process of the step of causing the chlorine to be adsorbed in the processing chamber11and then subjected to the process of the step of forming the ruthenium film604in the processing chamber13.FIG.6Bshows the cross section of the wafer that has been subjected to the process of the step of forming the ruthenium film604in the processing chamber13without being subjected to the process of the step of causing the chlorine to be adsorbed in the processing chamber11.

As shown inFIGS.6A and6B, it can be noted that a film thickness T1of the ruthenium film604(seeFIG.6A) when the process of the step of causing the chlorine to be adsorbed was performed in the processing chamber11is equal to or less than one half of a film thickness T2of the ruthenium film604(seeFIG.6B) when the process of the step of causing the chlorine to be adsorbed was not performed in the processing chamber11. From this result, it can be said that the chlorine adsorbed to the tungsten film603has an action of inhibiting the adsorption of the Ru-containing precursor.

In the above embodiment, there has been described the case where the step of causing the chlorine to be adsorbed and the step of forming the ruthenium film are performed in different processing containers connected via the vacuum transfer chamber. However, the present disclosure is not limited thereto. For example, the step of causing the chlorine to be adsorbed and the step of forming the ruthenium film may be performed in the same processing container. However, when the processing temperature differs between the step of causing the chlorine to be adsorbed and the step of forming the ruthenium film, it is preferable from the viewpoint of productivity that the step of causing the chlorine to be adsorbed and the step of forming the ruthenium film are performed in different processing containers.

According to the present disclosure in some embodiments, it is possible to form a ruthenium film with good embedding characteristics.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosures. Indeed, the embodiments described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the disclosures. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosures.