JP2023007137A - Film forming method and film forming device - Google Patents

Abstract

To provide a technique for precisely forming, in a desired region, an organic film that inhibits the formation of a target film.SOLUTION: A film formation method includes the steps (A) to (D): (A) preparing a substrate having, on its surface, a first region where a first film is exposed and a second region where a second film made of a material different from that of the first film is exposed; (B) supplying an organic compound to the surface of the substrate to form an organic film on both the first region and the second region; (C) selectively removing the organic film from the first region of the first region and the second region; and (D) selectively forming a first target film in the first region of the first region and the second region using the organic film remaining in the second region.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a film forming method and a film forming apparatus.

The film forming method described in Patent Document 1 includes the following (1) to (5). (1) A substrate is provided having a first substrate region and a second substrate region having at least two types of surfaces formed of a material different from that of the first substrate region. (2) selectively forming an intermediate film on the surface of the second substrate region; (3) selectively adsorbing the first self-assembled monolayer on the surface of the intermediate film; (4) selectively forming a target film on the surface of the first substrate region; (5) After forming the target film, the first self-assembled monolayer and the intermediate film are removed by etching.

The film forming method described in Patent Document 2 includes the following (1) to (2). (1) A passivation layer is selectively formed on the first surface of the first surface and the second surface, which are made of different materials, from a vapor phase reactant. The first surface is formed of metal and the second surface is formed of dielectric. (2) selectively depositing a layer of interest on a second surface from a vapor phase reactant using a passivation layer formed on the first surface; The material of the layer of interest may also deposit on the surface of the passivation layer, but may be removed by lift-off by etching the surface of the passivation layer.

Japanese Patent No. 2020-2452 JP 2018-137435 A

One aspect of the present disclosure provides a technique for forming an organic film that inhibits formation of a target film in a desired region with high accuracy.

A film formation method of one embodiment of the present disclosure includes the following (A) to (D). (A) Prepare a substrate having, on its surface, a first region where a first film is exposed and a second region where a second film made of a material different from the first film is exposed. (B) supplying an organic compound to the surface of the substrate to form an organic film on both the first region and the second region; (C) selectively removing the organic film from the first region of the first region and the second region; (D) Using the organic film remaining in the second region, a first target film is selectively formed in the first region out of the first region and the second region.

According to one aspect of the present disclosure, an organic film that inhibits formation of a target film can be accurately formed in a desired region.

FIG. 1 is a flow chart showing a film forming method according to one embodiment. FIG. 2 is a diagram showing an example of step S1 in FIG. FIG. 3 is a diagram showing an example of step S3 in FIG. FIG. 4 is a diagram showing an example of step S4 in FIG. FIG. 5 is a diagram showing an example of step S5 in FIG. FIG. 6 is a diagram showing an example of step S6 in FIG. FIG. 7 is a diagram showing an example of step S7 in FIG. FIG. 8 is a plan view showing a film forming apparatus according to one embodiment. 9 is a cross-sectional view showing an example of the first processing section of FIG. 8. FIG. 10 is a diagram showing concentration distributions of various atoms in Experimental Example 1. FIG. 11 is a diagram showing concentration distributions of various atoms in Experimental Example 2. FIG. 12 is a diagram showing concentration distributions of various atoms in Experimental Example 3. FIG. 13 is a diagram showing concentration distributions of various atoms in Experimental Example 4. FIG.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In addition, in each drawing, the same reference numerals are given to the same or corresponding configurations, and explanations thereof may be omitted.

[Deposition method]
First, a film forming method according to the present embodiment will be described with reference to FIGS. 1 to 7. FIG. The film forming method includes steps S1 to S7 shown in FIG. 1, for example. Note that the film forming method may include at least steps S1 and S3 to S5, and may not include steps S2 and S6 to S7, for example. The film forming method may include steps other than steps S1 to S7 shown in FIG.

Step S1 of FIG. 1 involves preparing a substrate 1, as shown in FIG. The substrate 1 has, on its surface, a first region A1 where the first film 11 is exposed and a second region A2 where the second film 12 is exposed. The second film 12 is made of a material different from that of the first film 11 . A first film 11 and a second film 12 are formed on a base substrate 10 . The underlying substrate 10 is a silicon wafer or a compound semiconductor wafer. Compound semiconductor wafers are, for example, GaAs wafers, SiC wafers, GaN wafers or InP wafers.

The first film 11 is, for example, a dielectric film. A conductive film or the like may be formed between the dielectric film and the underlying substrate 10 . The dielectric film is, for example, an interlayer insulating film. The interlayer insulating film is preferably a low dielectric constant (Low-k) film. The dielectric film is not particularly limited, but is, for example, a SiO film, SiN film, SiOC film, SiON film, or SiOCN film. Here, the SiO film means a film containing silicon (Si) and oxygen (O). The atomic ratio of Si and O in the SiO film is not limited to 1:1. The same applies to the SiN film, SiOC film, SiON film, and SiOCN film.

The second film 12 is made of a material different from that of the first film 11, as described above. The second film 12 is, for example, a metal film. The metal film is not particularly limited, but is, for example, a Cu film, a Co film, a Ru film, or a W film. Although the first film 11 is a dielectric film and the second film 12 is a metal film in this embodiment, the technology of the present disclosure is not limited to this. For example, the first film 11 may be a metal film and the second film 12 may be a dielectric film.

The first area A1 and the second area A2 are provided on one side of the substrate 1 in the thickness direction (for example, on the surface side). The number of first regions A1 and the number of second regions A2 are not particularly limited. Moreover, although the first area A1 and the second area A2 are adjacent to each other in FIG. 2, they may be separated from each other.

The substrate 1 may have a third region (not shown) on its surface. The third region is, for example, a region where the barrier film is exposed. A barrier film is formed between a metal film and a dielectric film to suppress metal diffusion from the metal film to the dielectric film. Although the barrier film is not particularly limited, it is, for example, a TaN film or a TiN film. Here, the TaN film means a film containing tantalum (Ta) and nitrogen (N). The atomic ratio of Ta and N in the TaN film is not limited to 1:1. The same is true for the TiN film.

The substrate 1 may further have a fourth region (not shown) on its surface. The fourth region is, for example, a region where the liner film is exposed. A liner film is formed over the barrier film to assist in the formation of the metal film. A metal film is formed over the liner film. Although the liner film is not particularly limited, it is, for example, a Co film or a Ru film.

Step S2 in FIG. 1 includes cleaning the surface of the substrate 1. FIG. For example, step S2 includes supplying a reducing gas such as H ₂ gas to the surface of substrate 1 to remove a native oxide film formed on the surface of substrate 1 . A natural oxide film is formed, for example, on the surface of a metal film. The reducing gas may be plasmatized. Also, the reducing gas may be used by being mixed with a rare gas such as Ar gas.

Step S2 may include supplying oxygen gas to the surface of the substrate 1 and irradiating the surface of the substrate 1 with ultraviolet rays. Ozone is generated by irradiation with ultraviolet light. Ozone ashing the organic matter adhering to the surface of the substrate 1 . In addition, ozone moderately oxidizes the surface of the metal film. If the natural oxide film is removed in advance, the density of oxygen atoms becomes the desired density by irradiation with ultraviolet rays. As a result, in step S3 described later, a dense organic film 13 can be formed on the surface of the metal film.

Step S3 in FIG. 1 supplies an organic compound to the surface of the substrate 1 to form an organic film 13 on both the first area A1 and the second area A2, as shown in FIG. A method for forming the organic film 13 is a physical vapor deposition (PVD) method, a chemical vapor deposition (CVD) method, or an atomic layer deposition (ALD) method. When the molecular weight of the organic compound is large, it is preferable to use physical vapor deposition.

The organic compound includes, for example, a linear chain and functional groups that chemisorb to both the first film 11 and the second film 12 at the ends of the linear chain. The linear chain of the organic compound is, for example, a hydrocarbon group or a substituent in which at least some hydrogen atoms of the hydrocarbon group are replaced with fluorine atoms. Functional groups are, for example, allyl groups or vinyl groups. The organic compound may contain side chains branched from straight chains, but preferably does not contain side chains.

A functional group present at the ends of the straight chains binds to the surface of the substrate 1 , and many straight chains are arranged on the surface of the substrate 1 . The organic film 13 has a structure similar to a so-called self-assembled monolayer (SAM). However, the organic film 13 may have a structure in which a plurality of monomolecules are stacked. The organic film 13 may have a structure in which a material (an etchant described below or a cleaning agent described below) used in step S<b>4 described later reaches the interface between the organic film 13 and the first film 11 .

Step S4 of FIG. 1 includes selectively removing the organic film 13 from the first area A1 of the first area A1 and the second area A2, as shown in FIG. By selectively removing the organic film 13 from the first region A1 by utilizing the difference in the materials of the first film 11 and the second film 12, the organic film 13 is precisely formed into a desired region (second region A2). can be formed well. It is possible to prevent the organic film 13 from protruding from the second region A2 into the first region A1, and eliminate the step of removing the portion of the organic film 13 protruding into the first region A1.

For example, step S4 selectively removes the organic film 13 from the first region A1 by selectively etching the first film 11 of the first film 11 and the second film 12 through the organic film 13. Including. That is, the organic film 13 is removed by lift-off. When the first film 11 is a dielectric film and the second film 12 is a metal film, the first film 11 is selectively etched with an etchant containing a halogen element. The etchant includes _NH4F , for example. The etchant can be liquid or gas. That is, the etching may be either wet etching or dry etching.

Alternatively, in step S4, among the bond between the first film 11 and the organic film 13 and the bond between the second film 12 and the organic film 13, the bond between the first film 11 and the organic film 13 is selectively cut, It includes selectively removing the organic film 13 from the first region A1. When the first film 11 is a metal film and the second film 12 is a dielectric film, the bonding of the first film 11 and the organic film 13 is performed using a cleaning agent containing alcohol and a solvent that dissolves the organic film 13 . is selectively cut. A solvent that dissolves the organic film 13 is, for example, a fluorine-based solvent. Alcohols include, for example, IPA (isopropyl alcohol) or ethanol. By adding alcohol to the solvent that dissolves the organic film 13, the bond between the first film 11 and the organic film 13 can be selectively cut.

When selectively cutting the bond between the first film 11 and the organic film 13 with a detergent, the organic compound that is the material of the organic film 13 preferably has an allyl group at the end of a linear chain. The allyl group chemisorbs to both the metal film and the dielectric film, but more strongly chemisorbs to the dielectric film than to the metal film. The bond between the metal film and the organic film 13 can be made weaker than the bond between the dielectric film and the organic film 13, and can be easily cut in step S4. The cleaning agent may be liquid or gaseous.

In step S4, by selecting which one of the above etchant and the above cleaning agent to use, it is possible to select whether to remove the organic film 13 on the metal film or to remove the organic film 13 on the dielectric film. It is also possible to

In step S5 of FIG. 1, as shown in FIG. 5, the organic film 13 remaining in the second region A2 is used to selectively apply a first target to the first region A1 of the first region A1 and the second region A2. Forming membrane 14 is included. The organic film 13 inhibits deposition of the first target film 14 in the second area A2 and selectively deposits the first target film 14 in the first area A1.

The first target film 14 is, for example, a dielectric film. A new dielectric film can be laminated on the dielectric film prepared in step S1. Note that the first film 11 may be a metal film as described above, in which case the first target film 14 is a metal film. A new metal film can be laminated on the metal film prepared in step S1.

The first target film 14 is, for example, an aluminum oxide film (AlO film), a silicon oxide film (SiO film), a silicon nitride film (SiN film), a zirconium oxide film (ZrO film), a hafnium oxide film (HfO film), or the like. be. Here, the AlO film means a film containing aluminum (Al) and oxygen (O). The atomic ratio of Al and O in the AlO film is not limited to 1:1. The same is true for the SiO film, SiN film, ZrO film, and HfO film.

The method of forming the first target film 14 is, for example, a physical vapor deposition (PVD) method, a chemical vapor deposition (CVD) method, or an atomic layer deposition (ALD) method. When a metal oxide is used as the material of the first target film 14, for example, physical vapor deposition is used. Physical vapor deposition methods include, for example, electron beam evaporation. Further, when an organometallic compound is used as the material of the first target film 14, for example, the CVD method or the ALD method is used. Although an example of the method of forming the first target film 14 has been shown by citing an example of the material of the first target film 14, the method is not limited to this and may be formed by any method.

When forming the first target film 14 by the ALD method, an organometallic compound gas and an oxidizing gas or a nitriding gas are alternately supplied to the surface of the substrate 1 . For example, when an AlO film is formed by the ALD method, an organoaluminum compound gas such as TMA (trimethylaluminum) gas and an oxidizing gas such as water vapor (H ₂ O gas) are alternately supplied to the surface of the substrate 1 . be. The organic film 13 is hydrophobic and inhibits the chemisorption of water vapor, thereby inhibiting the deposition of the AlO film.

Step S6 in FIG. 1 includes removing the organic film 13 remaining in the second area A2, as shown in FIG. A method for removing the organic film 13 is not particularly limited, but for example, a method of decomposing the organic film 13 with plasma gas, a method of ashing the organic film 13 with ozone, or a method of dissolving the organic film 13 with an organic solvent. methods are used. Note that step S6 can be performed simultaneously with step S5. For example, the material of the first target film 14 may be used to etch the organic film 13 .

Although not shown, steps S3 to S6 may be repeated multiple times. By repeating steps S3 to S6 a plurality of times, the film thickness of the first target film 14 can be increased.

Step S7 of FIG. 1 includes forming a second target film 15 of a material different from that of the first target film 14 in the second area A2 from which the organic film 13 has been removed, as shown in FIG. The method of forming the second target film 15 is, for example, a physical vapor deposition (PVD) method, a chemical vapor deposition (CVD) method, or an atomic layer deposition (ALD) method.

The second target film 15 is, for example, a metal film. A new metal film can be laminated on the metal film prepared in step S1. The second film 12 may be a dielectric film as described above, in which case the second target film 15 is a dielectric film. A new dielectric film can be laminated on the dielectric film prepared in step S1.

[Deposition equipment]
Next, a film forming apparatus 100 for carrying out the above film forming method will be described with reference to FIG. As shown in FIG. 8, the film forming apparatus 100 includes a first processing section 200A, a second processing section 200B, a third processing section 200C, a transport section 400, and a control section 500. 200 A of 1st process parts implement FIG.1 S3. The second processing unit 200B performs step S4 in FIG. 200 C of 3rd process parts implement FIG.1 S5. Although not shown, the film forming apparatus 100 may include a fourth processing section 200D that performs step S6 in FIG. 1, or a fifth processing section that performs step S7 in FIG. The first processing section 200A, the second processing section 200B, and the third processing section 200C have the same structure. Therefore, it is also possible to perform all steps S3 to S5 in FIG. 1 only by the first processing unit 200A. The transport section 400 transports the substrate 1 to the first processing section 200A, the second processing section 200B, and the third processing section 200C. The control unit 500 controls the first processing unit 200A, the second processing unit 200B, the third processing unit 200C, and the transport unit 400. FIG.

The transport section 400 has a first transport chamber 401 and a first transport mechanism 402 . The internal atmosphere of the first transfer chamber 401 is an air atmosphere. A first transport mechanism 402 is provided inside the first transport chamber 401 . The first transport mechanism 402 includes an arm 403 that holds the substrate 1 and travels along rails 404 . The rail 404 extends in the direction in which the carriers C are arranged.

Further, the transport section 400 has a second transport chamber 411 and a second transport mechanism 412 . The internal atmosphere of the second transfer chamber 411 is a vacuum atmosphere. A second transport mechanism 412 is provided inside the second transport chamber 411 . The second transport mechanism 412 includes an arm 413 that holds the substrate 1, and the arm 413 is arranged movably in the vertical and horizontal directions and rotatable around the vertical axis. The first processing section 200A, the second processing section 200B, and the third processing section 200C are connected to the second transfer chamber 411 through different gate valves G. As shown in FIG.

Furthermore, the transport section 400 has a load lock chamber 421 between the first transport chamber 401 and the second transport chamber 411 . The internal atmosphere of the load lock chamber 421 is switched between a vacuum atmosphere and an atmospheric atmosphere by a pressure regulating mechanism (not shown). Thereby, the inside of the second transfer chamber 411 can always be maintained in a vacuum atmosphere. In addition, the flow of gas from the first transfer chamber 401 to the second transfer chamber 411 can be suppressed. Gate valves G are provided between the first transfer chamber 401 and the load lock chamber 421 and between the second transfer chamber 411 and the load lock chamber 421 .

The control unit 500 is, for example, a computer, and has a CPU (Central Processing Unit) 501 and a storage medium 502 such as a memory. The storage medium 502 stores programs for controlling various processes executed in the film forming apparatus 100 . The control unit 500 controls the operation of the film forming apparatus 100 by causing the CPU 501 to execute programs stored in the storage medium 502 . The control unit 500 controls the first processing unit 200A, the second processing unit 200B, the third processing unit 200C, and the transfer unit 400 to carry out the film forming method described above.

Next, the operation of the film forming apparatus 100 will be described. First, the first transport mechanism 402 takes out the substrate 1 from the carrier C, transports the taken out substrate 1 to the load lock chamber 421 , and exits from the load lock chamber 421 . Next, the internal atmosphere of the load lock chamber 421 is switched from the air atmosphere to the vacuum atmosphere. After that, the second transport mechanism 412 takes out the substrate 1 from the load lock chamber 421 and transports the taken out substrate 1 to the first processing section 200A.

Next, the first processing unit 200A performs step S3. After that, the second transport mechanism 412 takes out the substrate 1 from the first processing section 200A and transports the taken out substrate 1 to the second processing section 200B. During this time, the atmosphere around the substrate 1 can be maintained in a vacuum atmosphere, and the deterioration of the blocking performance of the organic film 13 can be suppressed.

Next, the second processing section 200B carries out step S4. After that, the second transport mechanism 412 takes out the substrate 1 from the second processing section 200B and transports the taken out substrate 1 to the third processing section 200C. During this time, the atmosphere around the substrate 1 can be maintained in a vacuum atmosphere, and the deterioration of the blocking performance of the organic film 13 can be suppressed.

Next, the third processing unit 200C performs step S5. Subsequently, the control unit 500 checks whether steps S3 to S5 have been performed a set number of times. If the number of times of execution has not reached the set number of times, steps S3 to S5 are executed again.

Next, the second transport mechanism 412 takes out the substrate 1 from the third processing section 200</b>C, transports the taken out substrate 1 to the load lock chamber 421 , and exits from the load lock chamber 421 . Subsequently, the internal atmosphere of the load lock chamber 421 is switched from the vacuum atmosphere to the air atmosphere. After that, the first transport mechanism 402 takes out the substrate 1 from the load lock chamber 421 and stores the taken out substrate 1 in the carrier C. As shown in FIG. Then, the processing of the substrate 1 ends.

Next, the first processing section 200A will be described with reference to FIG. Note that the second processing unit 200B and the third processing unit 200C are configured in the same manner as the first processing unit 200A, so illustration and description thereof will be omitted. A fourth processing unit and a fifth processing unit (not shown) may be configured in the same manner as the first processing unit 200A.

The first processing section 200A includes a substantially cylindrical airtight processing container 210 . An exhaust chamber 211 is provided in the central portion of the bottom wall of the processing container 210 . The exhaust chamber 211 has, for example, a substantially cylindrical shape protruding downward. An exhaust pipe 212 is connected to the exhaust chamber 211 , for example, on the side surface of the exhaust chamber 211 .

An exhaust source 272 is connected to the exhaust pipe 212 via a pressure controller 271 . The pressure controller 271 comprises a pressure regulating valve such as a butterfly valve. The exhaust pipe 212 is configured such that the inside of the processing container 210 can be decompressed by the exhaust source 272 . The pressure controller 271 and the exhaust source 272 constitute a gas exhaust mechanism 270 that exhausts the gas inside the processing container 210 .

A transfer port 215 is provided on the side surface of the processing container 210 . The transfer port 215 is opened and closed by a gate valve G. Substrates 1 are carried in and out between the processing container 210 and the second transfer chamber 411 (see FIG. 8) through a transfer port 215 .

A stage 220 that is a holding portion for holding the substrate 1 is provided in the processing container 210 . The stage 220 horizontally holds the substrate 1 with the surface of the substrate 1 on which the first film and the second film are formed facing upward. The stage 220 has a substantially circular shape in plan view and is supported by a support member 221 . The surface of the stage 220 is formed with a substantially circular recess 222 for placing the substrate 1 having a diameter of 300 mm, for example. The recess 222 has an inner diameter slightly larger than the diameter of the substrate 1 . The depth of the concave portion 222 is substantially the same as the thickness of the substrate 1, for example. The stage 220 is made of a ceramic material such as aluminum nitride (AlN). Also, the stage 220 may be made of a metal material such as nickel (Ni). A guide ring for guiding the substrate 1 may be provided on the periphery of the surface of the stage 220 instead of the concave portion 222 .

A grounded lower electrode 223 is embedded in the stage 220, for example. A heating mechanism 224 is embedded under the lower electrode 223 . The heating mechanism 224 heats the substrate 1 placed on the stage 220 to a set temperature by receiving power from a power supply (not shown) based on a control signal from the control unit 500 (see FIG. 8). When the entire stage 220 is made of metal, the entire stage 220 functions as a lower electrode, so the lower electrode 223 does not have to be embedded in the stage 220 . The stage 220 is provided with a plurality of (for example, three) lifting pins 231 for holding and lifting the substrate 1 placed on the stage 220 . The material of the lifting pins 231 may be, for example, ceramics such as alumina (Al ₂ O ₃ ), quartz, or the like. A lower end of the lifting pin 231 is attached to a support plate 232 . The support plate 232 is connected to an elevating mechanism 234 provided outside the processing container 210 via an elevating shaft 233 .

The lifting mechanism 234 is installed, for example, in the lower part of the exhaust chamber 211 . The bellows 235 is provided between the lifting mechanism 234 and an opening 219 for the lifting shaft 233 formed on the lower surface of the exhaust chamber 211 . The shape of the support plate 232 may be a shape that allows it to move up and down without interfering with the support member 221 of the stage 220 . The elevating pin 231 is configured to be movable between above the surface of the stage 220 and below the surface of the stage 220 by means of an elevating mechanism 234 .

A gas supply unit 240 is provided on the ceiling wall 217 of the processing container 210 via an insulating member 218 . The gas supply part 240 forms an upper electrode and faces the lower electrode 223 . A high-frequency power source 252 is connected to the gas supply unit 240 via a matching device 251 . By supplying high frequency power of 450 kHz to 100 MHz from the high frequency power supply 252 to the upper electrode (gas supply unit 240), a high frequency electric field is generated between the upper electrode (gas supply unit 240) and the lower electrode 223, and capacitively coupled plasma is generated. is generated. A plasma generator 250 that generates plasma includes a matching box 251 and a high frequency power supply 252 . The plasma generation unit 250 is not limited to capacitively coupled plasma, and may generate other plasma such as inductively coupled plasma. Note that the first processing unit 200A does not need to include the plasma generation unit 250 when the plasma processing is unnecessary.

The gas supply unit 240 has a hollow gas supply chamber 241 . A large number of holes 242 for distributing and supplying the processing gas into the processing container 210 are, for example, evenly arranged on the lower surface of the gas supply chamber 241 . A heating mechanism 243 is embedded above, for example, the gas supply chamber 241 in the gas supply unit 240 . The heating mechanism 243 is heated to a set temperature by receiving power from a power supply (not shown) based on a control signal from the controller 500 .

A gas supply mechanism 260 is connected to the gas supply chamber 241 via a gas supply path 261 . The gas supply mechanism 260 supplies the gas used in at least one of steps S3 to S5 in FIG. Although not shown, the gas supply mechanism 260 includes an individual pipe for each type of gas, an on-off valve provided in the middle of the individual pipe, and a flow controller provided in the middle of the individual pipe. When the on-off valve opens the individual pipe, gas is supplied from the supply source to the gas supply path 261 . The amount of supply is controlled by a flow controller. On the other hand, when the opening/closing valve closes the individual pipe, the supply of gas from the supply source to the gas supply path 261 is stopped.

[Experimental data]
Experimental data will be described below.

<Experimental Examples 1 and 2>
In Experimental Example 1, a substrate including a Co film having a thickness of 100 nm deposited by PVD was prepared. After that, the Co film surface was irradiated with ultraviolet rays to generate ozone, which removed the organic matter adhering to the Co film surface and made the oxygen density on the Co film surface constant.

Next, at room temperature, an organic film was formed on the surface of the Co film by PVD. An organic compound having a perfluoropolyether in the main chain and an allyl group at the end of the main chain was prepared as an organic compound for the material of the organic film. This organic compound was placed in a crucible, vaporized, and deposited on the Co film surface at room temperature.

Next, the substrate was heated at 230° C. for 30 minutes in vacuum to remove excess organic compounds physically adsorbed on the Co film surface. As a result, an organic film was formed from the organic compound chemically adsorbed on the Co film surface. Although the substrate was not heated during vapor deposition of the organic compound in Experimental Example 1, it may be heated.

Next, the substrate was immersed in an aqueous NH ₄ F solution (NH ₄ F concentration: 40% by mass) at room temperature for 1 minute.

Next, Al ₂ O ₃ was supplied onto the organic film by an electron beam evaporation method. The supply amount was an amount corresponding to a film thickness of 6 nm. Here, the film thickness was measured with an ellipsometer by supplying Al ₂ O ₃ on the SiO ₂ film instead of the organic film. The temperature of the substrate was set to room temperature when supplying Al ₂ O ₃ onto the organic film.

Thereafter, scraping the substrate surface and measuring the composition of the substrate surface by X-ray Photoelectron Spectroscopy (XPS) were repeated. FIG. 10 shows the concentration distribution of various atoms in the depth direction measured by the XPS method.

As is clear from FIG. 10, the concentration of C atoms and F atoms decreased and the concentration of Co atoms increased until the cut depth reached D1. Further, after the depth reached D1, the concentration of C atoms and F atoms became almost constant, and the concentration of Co atoms became almost constant. Furthermore, the concentration of Al atoms remained low regardless of the depth of milling. The reason why the concentration of C atoms and F atoms does not become zero even when the depth is deeper than D1 is due to the background of the XPS spectrum. From the concentration distribution of various atoms in FIG. 10, it can be seen that the organic film remained on the Co film even when the substrate was immersed in the NH ₄ F aqueous solution, and the remaining organic film inhibited the deposition of Al ₂ O ₃ . .

On the other hand, in Experimental Example 2, the substrate was treated in the same manner as in Experimental Example 1, except that a substrate containing a SiO ₂ film was prepared instead of the Co film. Thereafter, grinding the substrate surface and measuring the composition of the substrate surface by the XPS method were repeated. FIG. 11 shows the concentration distribution of various atoms in the depth direction measured by the XPS method.

As is clear from FIG. 11, the concentrations of Al atoms, O atoms, C atoms, F atoms, and Si atoms were substantially constant regardless of the depth of cutting. The concentrations of Al atoms and O atoms were high, and the concentrations of C atoms, F atoms, and Si atoms were low. From the concentration distribution of various atoms in FIG. 11, it can be seen that almost no organic film remained on the SiO ₂ film after the substrate was immersed in the NH ₄ F aqueous solution, and an Al ₂ O ₃ film was deposited.

From the results of Experimental Examples 1 and 2, it can be seen that the NH ₄ F aqueous solution can selectively etch the SiO ₂ film out of the Co film and the SiO ₂ film, and can selectively remove the organic film from a specific region by lift-off. . Of the Co film and the SiO ₂ film, the organic film remains only on the Co film and inhibits the deposition of Al ₂ O ₃ . As a result, it is considered that the Al ₂ O ₃ film is selectively deposited on the SiO ₂ film between the Co film and the SiO ₂ film.

<Experimental Examples 3 and 4>
In Experimental Example 3, as in Experimental Example 1, a substrate including a Co film having a thickness of 100 nm formed by PVD was prepared. After that, the Co film surface was irradiated with ultraviolet rays to generate ozone, which removed the organic matter adhering to the Co film surface and made the oxygen density on the Co film surface constant.

Next, at room temperature, an organic film was formed on the surface of the Co film by PVD. An organic compound having a perfluoropolyether in the main chain and an allyl group at the end of the main chain was prepared as an organic compound for the material of the organic film. This organic compound was placed in a crucible, vaporized, and deposited on the Co film surface at room temperature.

Next, the substrate was heated at 230° C. for 30 minutes in vacuum to remove excess organic compounds physically adsorbed on the Co film surface. As a result, an organic film was formed from the organic compound chemically adsorbed on the Co film surface. Although the substrate was not heated during vapor deposition of the organic compound in Experimental Example 3, it may be heated.

Next, the substrate was immersed at room temperature for 1 minute in a cleaning solution containing 50% by mass of a fluorine-based solvent (manufactured by 3M, trade name HFE7200) and 50% by mass of IPA.

Next, Al ₂ O ₃ was supplied onto the organic film by an electron beam evaporation method. The supply amount was an amount corresponding to a film thickness of 6 nm. Here, the film thickness was measured with an ellipsometer by supplying Al ₂ O ₃ on the SiO ₂ film instead of the organic film. The temperature of the substrate was set to room temperature when supplying Al ₂ O ₃ onto the organic film.

Thereafter, scraping the substrate surface and measuring the composition of the substrate surface by X-ray Photoelectron Spectroscopy (XPS) were repeated. FIG. 12 shows the concentration distribution of various atoms in the depth direction measured by the XPS method.

As is clear from FIG. 12, the concentrations of Al atoms, O atoms, C atoms, F atoms, and Si atoms were substantially constant regardless of the depth of cutting. Also, the concentrations of Al atoms and O atoms were high, and the concentrations of C atoms, F atoms, and Si atoms were low. From the concentration distribution of various atoms in FIG. 12, it can be seen that almost no organic film remained on the Co film after being immersed in the above cleaning solution, and an Al ₂ O ₃ film was deposited.

On the other hand, in Experimental Example 4, the substrate was treated in the same manner as in Experimental Example 3, except that a substrate containing a SiO ₂ film was prepared instead of the Co film. Thereafter, grinding the substrate surface and measuring the composition of the substrate surface by the XPS method were repeated. FIG. 13 shows the concentration distribution of various atoms in the depth direction measured by the XPS method.

As is clear from FIG. 13, the concentrations of C atoms and F atoms decreased and the concentrations of Si atoms and O atoms increased until the cut depth reached D2. After the cut depth reached D2, the concentrations of C atoms and F atoms became substantially constant, and the concentrations of Si atoms and O atoms became substantially constant. Furthermore, the concentration of Al atoms remained low regardless of the depth of milling. From the concentration distribution of various atoms in FIG. 13, it can be seen that the organic film remained _on the _SiO2 film even after the substrate was immersed in the above cleaning solution, and the remaining organic film inhibited the deposition of _Al2O3 . .

From the results of Experimental Examples 3 and 4, the above cleaning solution can selectively cut the bond between the Co film and the organic film, out of the bond between the Co film and the organic film and the bond between the _SiO2 film and the organic film. can be selectively removed from specific regions. Of the Co film and the SiO ₂ film, the organic film remains only on the SiO ₂ film and inhibits the deposition of Al ₂ O ₃ . As a result, it is considered that the Al ₂ O ₃ film is selectively deposited on the Co film between the Co film and the SiO ₂ film.

Although the embodiments of the film forming method and film forming apparatus according to the present disclosure have been described above, the present disclosure is not limited to the above embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These also naturally belong to the technical scope of the present disclosure.

1 substrate 11 first film 12 second film 13 organic film 14 first target film A1 first region A2 second region

Claims (14)

Preparing a substrate having on its surface a first region where a first film is exposed and a second region where a second film made of a material different from the first film is exposed;
supplying an organic compound to the surface of the substrate to form an organic film on both the first region and the second region;
selectively removing the organic film from the first region of the first region and the second region;
selectively forming a first target film in the first region out of the first region and the second region, using the organic film remaining in the second region;
A film forming method, comprising: 2. The film forming method according to claim 1, wherein said organic compound includes a straight chain, and a functional group at the end of said straight chain that chemically adsorbs to both said first film and said second film. 3. The film forming method according to claim 2, wherein the linear chain is a hydrocarbon group or a substituent obtained by substituting fluorine atoms for at least some hydrogen atoms of the hydrocarbon group. 4. The film forming method according to claim 2, wherein said functional group is an allyl group. 5. The organic film is selectively removed from the first region by selectively etching the first film out of the first film and the second film through the organic film. The film forming method according to any one of the above. 6. The film forming method according to claim 5, wherein said first film is selectively etched with an etchant containing a halogen element. The film forming method according to claim 6, wherein the etchant contains _NH4F . selected from the first region by selectively cutting the bond between the first film and the organic film among the bond between the first film and the organic film and the bond between the second film and the organic film 5. The method of forming a film according to claim 1, wherein the organic film is physically removed. 9. The film formation method according to claim 8, wherein a bond between said organic film and said first film is selectively cut with a cleaning agent containing a solvent that dissolves said organic film and alcohol. The film forming method according to claim 9, wherein the alcohol includes at least one of IPA and ethanol. The first film is a metal film and the second film is a dielectric film, or the first film is a dielectric film and the second film is a metal film. 11. The film forming method according to any one of 10. 12. The film forming method according to claim 11, wherein said metal film is a Cu film, a Co film, a Ru film, or a W film. 13. The film forming method according to claim 11, wherein said dielectric film is a SiO film, SiN film, SiOC film, SiON film, or SiOCN film. A film forming apparatus for processing a substrate having a first region where a first film is exposed and a second region where a second film formed of a material different from that of the first film is exposed,
a first processing unit that supplies an organic compound to the surface of the substrate to form an organic film on both the first region and the second region;
a second processing unit that selectively removes the organic film from the first region of the first region and the second region;
a third processing unit that selectively forms a target film in the first region out of the first region and the second region, using the organic film remaining in the second region;
A film forming apparatus.

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