Substrate processing method and substrate processing apparatus

Abstract

[Problem] To provide a technique for reducing leakage current in high-dielectric films. [Solution] A substrate processing method comprising the following (A) to (C): (A) Preparing a substrate having a high-dielectric film with a higher dielectric constant than that of a SiO2 film. (B) Supplying a metal solution containing a second metal element to the aforementioned substrate, wherein the second metal element has a higher cathode or a lower valence than the first metal element contained in the aforementioned high-dielectric film. (C) Forming a doped layer on the surface of the aforementioned high-dielectric film, wherein the first metal element is replaced by the second metal element.

Description

[Technical Field]

[0001] This disclosure relates to a substrate processing method and a substrate processing apparatus. [Previous Technology]

[0002] The capacitor with a semiconductor layer described in Patent Document 1 is formed by distributing a dielectric film between an upper electrode and a lower electrode. The dielectric film comprises a film in which hafnium oxide and titanium oxide are alternately deposited at the atomic level. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2009-59889 [Summary of the Invention]

[0004] [The problem that this invention aims to solve]

[0005] One aspect of this disclosure is to provide a technique for reducing leakage current in high-dielectric films. [Means for solving the problem]

[0006] The substrate processing method disclosed herein includes the following steps (A) to (C): (A) Preparing a substrate having a high-dielectric film with a higher dielectric constant than that of a SiO2 film. (B) Supplying a metal solution containing a second metal element to the aforementioned substrate, wherein the second metal element has a higher cathode or a lower valence than the first metal element contained in the aforementioned high-dielectric film. (C) Forming a doped layer on the surface of the aforementioned high-dielectric film, wherein the first metal element is replaced by the aforementioned second metal element. [Effects of the Invention]

[0007] According to one of the states disclosed herein, leakage current of high dielectric films can be reduced.

Implementation Method

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In addition, in each drawing, the same or corresponding components are sometimes given the same symbols and the description is omitted.

[0010] First, before describing the substrate processing method of this embodiment, referring to FIG1, we will describe the substrate 10 obtained by using the substrate processing method. The substrate 10 is a semiconductor element, for example, including a capacitor. The substrate 10 includes, for example: a semiconductor substrate 11; a first electrode 12; a high-dielectric film 13; a doped layer 14; and a second electrode 15.

[0011] The semiconductor substrate 11 is, for example, a silicon wafer. The silicon wafer may also contain p-type dopants such as phosphorus or n-type dopants such as boron. The semiconductor substrate 11 may also be a compound semiconductor wafer. The compound semiconductor wafer is not particularly limited and may be, for example, a GaAs wafer, a SiC wafer, a GaN wafer, or an InP wafer.

[0012] The first electrode 12 and the second electrode 15 are conductive films, such as TiN films. The TiN film is formed by ALD (Atomic Layer Deposition) or CVD (Chemical Vapor Deposition) methods. When the semiconductor substrate 11 contains dopants, the first electrode 12 may also be part of the semiconductor substrate 11.

[0013] The high-dielectric film 13 has a higher dielectric constant than the SiO2 film. The high-dielectric film 13 may, for example, contain a zirconium oxide film or a hafnium oxide film. The high-dielectric film 13 is formed by ALD or CVD methods. While the high-dielectric film 13 is a single-layer structure in this embodiment, it may also be a multi-layer structure. The multi-layer high-dielectric film 13 may be, for example, a ZrO2 film / Al2O3 film / ZrO2 film, a ZrO2 film / Al2O3 film, or a HfO2 film / Al2O3 film. Preferably, the uppermost layer of the multi-layer high-dielectric film 13 containing a zirconium oxide film or a hafnium oxide film forms the doped layer 14.

[0014] The substrate processing method of this embodiment, as described below, includes forming a doped layer 14 on the surface of the high-dielectric film 13 before forming the second electrode 15 on the surface of the high-dielectric film 13. The doped layer 14 is a so-called monolayer. As detailed below, by forming the doped layer 14, the Schottky barrier can be modulated, and the increase in the thickness of the high-dielectric film 13 can be suppressed while reducing leakage current.

[0015] Next, referring to FIG2, the substrate processing method of this embodiment will be described. The substrate processing method includes steps S101 to S108 shown in FIG2. Alternatively, the substrate processing method may not include all steps S101 to S108 shown in FIG2, or may include steps not shown.

[0016] Step S101 includes: preparing the substrate 10. Preparing the substrate 10 includes, for example, transferring the substrate 10 into the substrate processing apparatus 20 (see FIG. 11). On the surface of the substrate 10, the second electrode 15 is not formed and the high-dielectric film 13 is exposed. The high-dielectric film 13 shown in FIG. 3(A) is a zirconium oxide film. The high-dielectric film 13 includes oxygen voids 13a formed during the formation of the high-dielectric film 13.

[0017] Step S102 includes: repairing oxygen voids 13a in the high-dielectric film 13 with an oxidizing agent before forming the doped layer 14. The oxidizing agent is an oxidizing solution. Examples of oxidizing solutions include ozone water, SC1 (an aqueous solution containing ammonium hydroxide and hydrogen peroxide), hydrogen peroxide water, or SPM (an aqueous solution containing sulfuric acid and hydrogen peroxide). As shown in Figure 3(B), the oxidizing agent reduces oxygen voids 13a and decreases the path of leakage current. Therefore, leakage current can be reduced.

[0018] Step S102 described above includes, for example, dispensing an oxidizing solution from a nozzle positioned above the substrate 10 onto the surface of the high-dielectric film 13 while the high-dielectric film 13 is facing upwards and the substrate 10 is held horizontally, forming a liquid film of the oxidizing solution. At this time, the substrate 10 can also be rotated. Furthermore, the nozzle can also be scanned along the radial direction of the substrate 10. The nozzle can also be a two-fluid nozzle, and can also supply the substrate 10 with a spray of the oxidizing solution. The oxidizing solution is collected in the cup 26 (see Figure 11).

[0019] In addition, step S102 may also include immersing the substrate 10 in an oxidizing solution stored inside a processing tank. When the substrate 10 is immersed in an oxidizing solution, multiple substrates 10 can be processed in batches.

[0020] Step S103 includes: supplying a metal solution containing a second metal element to the substrate 10. This second metal element has a higher cathode or a lower valence than the first metal element contained in the high-dielectric film 13. As shown in FIG3(C), when the high-dielectric film 13 is zirconium oxide, the first metal element is zirconium (Zr). Furthermore, when the high-dielectric film 13 is hafnium oxide, the first metal element is hafnium (Hf). Both Zr and Hf have a valence of 4.

[0021] The metal solution, as described above, contains a second metal element that has a higher degree of cathode charge or a lower valence number compared to the first metal element. The second metal element may also have a higher degree of cathode charge and a lower valence number compared to the first metal element. As will be described later, by replacing the first metal element contained in the high-dielectric film 13 with the second metal element contained in the metal solution, a dipole moment can be formed on the surface of the high-dielectric film 13.

[0022] The second metallic element comprises one or more selected from, for example, Co, Ni, Mo, W, V, Cr, and Nb. From the viewpoint of substitutability with the first metallic element, it is preferable that the second metallic element has a smaller difference in ionic radius from the first metallic element. Therefore, the second metallic element preferably comprises one or more selected from Co, Ni, and Nb. Co, Ni, and Nb have smaller differences in ionic radius from Zr and Hf. The second metallic element shown in Figure 3(C) is Co.

[0023] The metal solution is, for example, an aqueous solution of an inorganic acid salt containing a second metal element. The inorganic acid salt is not particularly limited, and may be, for example, a sulfate, nitrate, or nitrate salt.

[0024] To improve the wettability relative to the high-dielectric membrane 13, the metal solution may also contain an organic solvent with excellent hydration properties. IPA or acetone, for example, are used as the organic solvent. By improving the wettability of the metal solution, the rate at which the first metal element contained in the high-dielectric membrane 13 is replaced by the second metal element contained in the metal solution can be improved.

[0025] Step S103 described above includes, for example, dispensing a metal solution from a nozzle positioned above the substrate 10 onto the surface of the high-dielectric film 13 while the high-dielectric film 13 is facing upwards and the substrate 10 is held horizontally, forming a liquid film of the metal solution. At this time, the substrate 10 can also be rotated. Furthermore, the nozzle can also be scanned along the radial direction of the substrate 10. The nozzle can also be two fluid nozzles, and can also supply a spray of the metal solution to the substrate 10. The metal solution is collected in the cup 26 (see FIG. 11).

[0026] In addition, step S103 may also include immersing the substrate 10 in a metal solution stored inside a processing tank. When the substrate 10 is immersed in the metal solution, multiple substrates 10 can be processed in batches.

[0027] Step S104 includes forming a doped layer 14 on the surface of the high-dielectric film 13, in which the first metal element is replaced by a second metal element. As shown in FIG3(D), the first metal element contained in the high-dielectric film 13 is replaced by a second metal element contained in the metal solution. As a result, the doped layer 14 is formed from the surface of the high-dielectric film 13 at a predetermined depth. The doped layer 14 is a monolayer, and its thickness is, for example, 1 to 5 times the atomic radius of the second metal element. The doping that forms a monolayer is generally referred to as MLD (Monolayer Doping).

[0028] The second metal element, as described above, has a higher degree of cathode charge or a lower valence number compared to the first metal element. Therefore, as shown in FIG4, a dipole moment can be formed on the surface of the high-dielectric film 13. As a result, as shown by arrow A1 in FIG5, the Schottky barrier can be modulated, and the flow of electrons as shown by arrow A2 in FIG5 can be blocked. Therefore, the increase in the thickness of the high-dielectric film 13 can be suppressed while the leakage current is reduced.

[0029] The areal density of the second metal element in the surface of the high-dielectric film 13 is above 1×10¹⁰ atoms / cm² and below 1×10¹⁵ atoms / cm². The areal density of the second metal element is measured by SIMS (secondary ion mass analysis), ICP-MS (inductively coupled plasma mass analysis), or TXRF (total internal reflection fluorescence X-ray diffraction).

[0030] If the areal density of the second metal element on the surface of the high-dielectric film 13 is within the desired range, post-washing such as rinsing is not required after step S104. However, if there is an excess of the second metal element, post-washing is performed.

[0031] However, step S104, as described above, includes replacing the first metal element contained in the high-dielectric film 13 with a second metal element, which has a higher degree of cathode charge or a lower valence number compared to the first metal element. As a result, in order to achieve charge balance, as shown in FIG3(D), new oxygen vacancies 13a are sometimes generated.

[0032] Step S105 includes: after forming the doped layer 14, repairing the oxygen voids 13a in the high-dielectric film 13 with an oxidizing agent. The oxidizing agent is an oxidizing solution used in the same manner as in step S102, and the solution is supplied to the substrate 10. As shown in FIG3(E), the oxidizing agent reduces the oxygen voids 13a and decreases the path of leakage current.

[0033] In addition, the oxidizing solution can also be supplied to the substrate 10 simultaneously with the metal solution. That is, the formation of the doped layer 14 (step S104) and the repair of oxygen voids 13a (step S102 or S105) can be carried out simultaneously.

[0034] In this embodiment, the repair of oxygen voids 13a is a wet process, but it can also be a dry process. For example, step S105 may also include: after forming the doped layer 14, heating the substrate 10 in an atmosphere containing oxygen, thereby repairing the oxygen voids 13a in the high-dielectric film 13. The heating temperature of the substrate 10 is, for example, 80°C to 500°C, preferably 100°C to 350°C. As long as oxygen is present, most of the atmosphere can also be an inert gas such as nitrogen. The atmosphere can also be an atmospheric atmosphere.

[0035] Furthermore, step S105 may also include: after forming the doped layer 14, irradiating the substrate 10 with ultraviolet light in an atmosphere containing oxygen, thereby repairing the oxygen voids 13a in the high-dielectric film 13. Ozone is generated by the ultraviolet irradiation, and the ozone repairs the oxygen voids 13a. The wavelength of the ultraviolet light is not particularly limited, for example, 172nm or 365nm.

[0036] In addition, step S105 may also include a plurality of processes for repairing oxygen cavities 13a. The combination is not particularly limited.

[0037] Step S106 includes cleaning the substrate 10. For example, step S106 includes cleaning the back side (e.g., the bottom) or slope of the substrate 10 opposite to the doped layer 14 with a cleaning solution to remove the second metal element adhering to the back side or slope. Both the back side and the slope can be cleaned. The cleaning solution contains an inorganic acid. The cleaning solution is, for example, hydrofluoric acid, dilute hydrochloric acid, SC2 (an aqueous solution containing hydrochloric acid and hydrogen peroxide), SPM, or aqua regia. This can prevent the second metal element from adhering to the conveying device, etc., that transports the substrate 10.

[0038] Step S106 described above includes, for example, dispensing cleaning liquid from a nozzle disposed below the substrate 10 while the high-dielectric film 13 is facing upwards and the substrate 10 is held horizontally. The substrate 10 may also be rotated at this time. The nozzle may be a two-fluid nozzle, and may also supply a spray of cleaning liquid to the substrate 10. The cleaning liquid is collected in the cup 26 (see FIG. 11).

[0039] Step S107 includes drying the substrate 10. The drying method for the substrate 10 is, for example, rotary drying, supercritical drying, or Marangoni drying. In these drying processes, an organic solvent such as IPA is used. Compared to pure water, the organic solvent can reduce the surface tension acting on the substrate surface and can suppress pattern deflection on the substrate surface. The organic solvent is supplied to the substrate 10 in a liquid or gaseous state. Nitrogen or the like can also be supplied to the substrate 10 together with the organic solvent. In supercritical drying, the liquid film of the organic solvent formed on the surface of the substrate 10 is pre-displaced into a supercritical fluid, thereby drying the substrate 10.

[0040] Alternatively, before drying the substrate 10, a water-repellent agent can be used to water-repel the substrate 10, thereby reducing the surface tension of the organic solvent acting on the substrate surface. The water-repellent agent is not particularly limited, and may be, for example, (trimethylsilyl)dimethylamine (TMSDMA) or hexamethyldisilazane (HMDS), etc.

[0041] Step S108 includes: removing the substrate 10 from the substrate processing apparatus 20. Thereafter, a second electrode 15 is formed on the doped layer 14 of the substrate 10.

[0042] Furthermore, the substrate processing method may also include steps not shown in FIG2. For example, the substrate processing method may also include: washing the cup 26 or the processing container 21 to remove the second metal element adhering to the cup 26 or the processing container 21. The washing of the cup 26 is performed using an aqueous solution of inorganic acid. The washing of the processing container 21 is performed using gas.

[0043] Next, referring to Table 1, etc., the experimental data will be explained. Table 1 shows the processing conditions for Examples 1 to 8. In Examples 1 to 8, films were formed on a silicon wafer in the order of TiN film, ZrO2 film, and TiN film, except for the processing conditions shown in Table 1. The thickness of the ZrO2 film was 5 nm. Example 1 is a comparative example, and Examples 2 to 8 are exemplary examples.

[0044] [Table 1] Doping Preprocessing SPM+DHF Post-processing 1 heating Second post-processing H2O2 Example 1 none none none none Example 2 have none none none Example 3 have none none have Example 4 have none have none Example 5 have none have have Example 6 have have none none Example 7 have have none have Example 8 have have none have

[0045] In Table 1, in the "Doping Process," before forming the TiN film on the surface of the ZrO2 film, the substrate was immersed in an aqueous solution containing 10 ppm Co ions by mass for 30 minutes, and then dried with compressed air. In the "Pretreatment," after the formation of the ZrO2 film and before the doping process, SPM was supplied to the surface of the ZrO2 film for 1 minute, followed by DHF (dilute hydrofluoric acid) for 1 minute. As the SPM, a sulfuric acid to hydrogen peroxide mass ratio of 6:1 (H2SO4:H2O2=6:1) was used. As the DHF, a hydrofluoric acid to water mass ratio of 1:100 (H2O2:H2O=1:100) was used. In the "First Post-Treatment," after the doping process and before the formation of the TiN film, the substrate was heated at 100°C in an atmospheric atmosphere. In the "second post-processing", after the doping treatment and before the formation of the TiN film, the substrate is immersed in hydrogen peroxide water for 10 seconds, and then dried with compressed air. The hydrogen peroxide water used contains 1.5% by mass of H2O2.

[0046] In Examples 1 to 8, 60 test pieces were fabricated under the processing conditions shown in Table 1. As shown in FIG. 6, a voltage was applied to each test piece, and the leakage current was measured. In Example 1, as shown in Table 1, no doping treatment was performed. Therefore, the test piece fabricated in Example 1 does not have the doped layer 14 shown in FIG. 6.

[0047] Figure 7 shows the measurement results of Examples 1 and 8. In Figure 7, the vertical axis represents the cumulative probability (%), and the horizontal axis represents the leakage current (A / cm2). The leakage current is expressed logarithmically. Also, in Figure 7, the horizontal line B1 represents a cumulative probability of 50%. The median value of the leakage current of the test piece prepared in Example 1 is used as the reference value of the leakage current.

[0048] As can be clearly seen from Figure 7, since Example 8 differs from Example 1 in that it incorporates doping treatment, pretreatment, a first post-treatment, and a second post-treatment, the leakage current can be reduced compared to Example 1. For example, in Example 8, the central value of the leakage current can be reduced to approximately 1 / 20 of the reference value. Furthermore, in Example 8, the deviation of the leakage current can be reduced, and the leakage current of most test pieces can be made smaller than the reference value.

[0049] In Figure 8, the measurement results of Examples 1 to 8 are shown in bar chart. In Figure 8, "less than 1 / 10 of the reference value" indicates the proportion of test pieces with leakage current less than 1 / 10 of the reference value, and "short circuit" indicates the proportion of test pieces with leakage current exceeding 10 A / cm2.

[0050] As can be clearly seen from Figure 8, since doping treatment was performed in Example 2, unlike Example 1, the proportion of test pieces with leakage current of 1 / 10 of the reference value can be increased compared to Example 1. Furthermore, since at least one of the first and second post-treatments was performed in Examples 3 to 5, unlike Example 2, the proportion of short-circuited test pieces can be reduced compared to Example 2. Moreover, since pre-treatment was performed in Example 6, unlike Example 2, the proportion of test pieces with leakage current of 1 / 10 of the reference value can be increased compared to Example 2, and the proportion of short-circuited test pieces can be reduced. Furthermore, since at least a second post-treatment was performed in Examples 7 to 8, unlike Example 6, not only pre-treatment but also at least a second post-treatment was performed, the proportion of test pieces with leakage current of 1 / 10 of the reference value can be increased compared to Example 6, and the proportion of short-circuited test pieces can be reduced.

[0051] Next, referring to FIG9, the substrate processing method of the modified example will be explained. The substrate processing method of the modified example includes steps S101 to S102, S105 to S108, and S201 to S202 shown in FIG9. Hereinafter, the differences will be mainly explained.

[0052] Step S201 includes: supplying a polar organic solvent to the substrate. The polar organic solvent may contain, for example, a carbonyl compound or an amine compound. The carbonyl compound is not particularly limited and may be, for example, acetone, formaldehyde, or cyclohexanone. The amine compound is not particularly limited and may be, for example, triethylamine or trimethylamine.

[0053] Step S201 described above includes, for example, dispensing an organic solvent from a nozzle positioned above the substrate 10 onto the surface of the high-dielectric film 13 while the high-dielectric film 13 is facing upwards and the substrate 10 is held horizontally, forming a liquid film of the organic solvent. At this time, the substrate 10 can also be rotated. Furthermore, the nozzle can also be scanned along the radial direction of the substrate 10. The nozzle can also be two fluid nozzles, and can also supply a spray of the organic solvent to the substrate 10. The organic solvent is collected in the cup 26 (see FIG. 11).

[0054] Additionally, step S201 may also include immersing the substrate 10 in an organic solvent stored inside a processing tank. When the substrate 10 is immersed in the organic solvent, multiple substrates 10 can be processed in batches. Furthermore, the organic solvent may be supplied to the substrate 10 in a gaseous state rather than a liquid state.

[0055] Step S202 includes: adsorbing an organic solvent onto the surface of the high-dielectric film 13 to form an adsorption layer containing the organic solvent. When a carbonyl compound is supplied as the organic solvent, as shown in FIG10, the carbonyl group will adsorb onto the surface of the high-dielectric film 13 to form an adsorption layer 16. The adsorption layer 16 is a monolayer, and its thickness is, for example, 1 to 5 times the thickness of one molecule of the organic solvent.

[0056] By forming the adsorption layer 16, a dipole moment is formed on the surface of the high-dielectric film 13. As a result, similar to the case where a doped layer 14 is formed in place of the adsorption layer 16, as shown by arrow A1 in FIG5, the Schottky barrier can be modulated, and the flow of electrons as shown by arrow A2 in FIG5 can be blocked. Therefore, the increase in the thickness of the high-dielectric film 13 can be suppressed while reducing leakage current.

[0057] Next, referring to Table 2, etc., the experimental data will be explained. Table 2 shows the experimental results of Examples 1 and 9. In Example 9, except that "adsorption treatment" was applied instead of "doping treatment", the same conditions as in Example 2 were used to form a TiN film, a ZrO2 film, and a TiN film on a silicon wafer in that order. In the adsorption treatment, the substrate was immersed in acetone for 30 seconds, and then the substrate was dried with compressed air. Example 1 is a comparative example, and Example 9 is an exemplary example.

[0058] [Table 2] median value of leakage current (au) Example 1 1 Example 9 0.38

[0059] As can be clearly seen from Table 2, since adsorption treatment was performed in Example 9, unlike in Example 1, the leakage current can be reduced compared to Example 1. Specifically, in Example 9, the median value of the leakage current can be reduced to about 2 / 5 of the reference value.

[0060] Next, referring to FIG11, the substrate processing apparatus 20 of this embodiment will be described. The substrate processing apparatus 20 includes, for example: a processing container 21; a gas supply mechanism 22; a chuck 23; a chuck drive mechanism 24; a liquid supply mechanism 25; a cover cup 26; and a control unit 29. The processing container 21 houses the substrate 10. The gas supply mechanism 22, including a fan filter unit, supplies gas to the interior of the processing container 21. The chuck 23 is a substrate holding part that holds the substrate 10 inside the processing container 21. The chuck drive mechanism 24 rotates the chuck 23. The liquid supply mechanism 25 supplies processing liquid to the substrate 10 held by the chuck 23. The cover cup 26 collects the processing liquid ejected from the rotating substrate 10. The control unit 29 controls the gas supply mechanism 22, the chuck drive mechanism 24, and the liquid supply mechanism 25.

[0061] The liquid supply mechanism 25 has a nozzle 251 for dispensing processing liquid. The nozzle 251 dispenses processing liquid from above onto the substrate 10 held by the chuck 23. The processing liquid is supplied to the radial center of the rotating substrate 10, and by centrifugal force, it expands throughout the radial direction of the substrate 10 to form a liquid film. The number of nozzles 251 is one or more. A plurality of nozzles 251 can dispense a plurality of types of processing liquid, or a single nozzle 251 can dispense a plurality of types of processing liquid.

[0062] Examples of processing liquids include, for instance, the oxidizing solution used in step S102 or S105, the metal solution used in steps S103 and S104, the cleaning solution used in step S106, and the organic solvent used in step S201. The liquid supply mechanism 25 is equivalent to the liquid supply unit or organic solvent supply unit described in the claims.

[0063] The liquid supply mechanism 25 has a flow path for supplying the liquid to the nozzle 251 for each type of liquid. Furthermore, the liquid supply mechanism 25 includes, in the middle of the flow path: a flow meter; a flow controller; and a switching valve. The flow meter measures the flow rate of the liquid. The flow controller controls the flow rate of the liquid. The switching valve opens and closes the flow path.

[0064] Furthermore, the liquid supply mechanism 25 includes a nozzle drive unit 252 that moves the nozzle 251. The nozzle drive unit 252 moves the nozzle 251 in a horizontal direction orthogonal to the rotation center line of the chuck 23. The nozzle drive unit 252 can also move the nozzle 251 in a vertical direction. During the process of the nozzle 251 dispensing liquid onto the substrate surface, the nozzle drive unit 252 can also move the nozzle 251 in a radial direction along the substrate surface.

[0065] The cup 26 houses the substrate 10 held by the chuck 23 and recovers the processing liquid ejected from the rotating substrate 10. A drain pipe 261 and an exhaust pipe 262 are provided at the bottom of the cup 26. The drain pipe 261 discharges the liquid stored inside the cup 26. The exhaust pipe 262 discharges the gas inside the cup 26. The cup 26 does not rotate with the chuck 23, but it can still rotate.

[0066] The control unit 29, such as a computer, includes a CPU (Central Processing Unit) 291 and a memory medium 292. The memory medium 292 stores programs that control various processes executed in the board processing apparatus 20. The control unit 29 controls the operation of the board processing apparatus 20 by causing the CPU 291 to execute the programs stored in the memory medium 292, thereby implementing the board processing method shown in FIG2 or FIG9.

[0067] While the embodiments of the substrate processing method and substrate processing apparatus disclosed herein have been described above, this disclosure is not limited to the aforementioned embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope described in the claims. These, of course, also fall within the technical scope of this disclosure. [Simplified Explanation of the Diagram]

[0008] [Fig. 1] Fig. 1 is a cross-sectional view of a substrate obtained by a substrate processing method according to an embodiment. [Fig. 2] Fig. 2 is a flowchart of a substrate processing method according to an embodiment. [Fig. 3] Fig. 3(A) is a cross-sectional view of the substrate in S101 of Fig. 2, Fig. 3(B) is a cross-sectional view of the substrate in S102 of Fig. 2, Fig. 3(C) is a cross-sectional view of the substrate in S103 of Fig. 2, Fig. 3(D) is a cross-sectional view of the substrate in S104 of Fig. 2, and Fig. 3(E) is a cross-sectional view of the substrate in S105 of Fig. 2. [Fig. 4] Fig. 4 is a cross-sectional view showing an example of a dipole moment formed on the surface of a high-dielectric film. [Fig. 5] Fig. 5 is a diagram showing an example of an increase in the Schottky barrier caused by the dipole moment. [Figure 6] Figure 6 is a diagram showing an example of a test method for the leakage current of a high-dielectric film. [Figure 7] Figure 7 is a diagram showing the evaluation results of processing conditions 1 and 8 in Table 1. [Figure 8] Figure 8 is a diagram showing the evaluation results of processing conditions 1 to 8 in Table 1. [Figure 9] Figure 9 is a flowchart showing a modified example of a substrate processing method. [Figure 10] Figure 10 is a cross-sectional view showing another example of a dipole moment formed on the surface of a high-dielectric film. [Figure 11] Figure 11 is a cross-sectional view showing an example of a substrate processing apparatus.

Claims

1. A substrate processing method, characterized in that it comprises: preparing a substrate having a high dielectric film having a higher dielectric constant than that of a SiO2 film; supplying the substrate with a metal solution containing a second metal element, wherein the second metal element has a higher cathode or a lower valence than the first metal element contained in the high dielectric film; and forming a doped layer on the surface of the high dielectric film in which the first metal element is replaced by the second metal element.

2. The substrate processing method as described in claim 1, wherein, The aforementioned second metallic element includes one or more selected from Co, Ni, Mo, W, V, Cr and Nb.

3. The substrate processing method as described in claim 1 or 2, wherein, The aforementioned metal solution is an aqueous solution containing an inorganic acid salt of the aforementioned second metal element.

4. The substrate processing method as described in claim 1 or 2, wherein, The areal density of the second metal element mentioned above on the aforementioned surface of the aforementioned high dielectric film is above 1×10¹⁰ atoms / cm² and below 1×10¹⁵ atoms / cm².

5. The substrate processing method as described in claim 1 or 2, wherein, It includes: repairing oxygen voids in the aforementioned high-dielectric film with an oxidant before forming the aforementioned doped layer.

6. The substrate processing method as described in claim 1 or 2, wherein, It includes: after forming the aforementioned doped layer, repairing oxygen voids in the aforementioned high-dielectric film with an oxidant.

7. The substrate processing method as described in claim 5, wherein, The aforementioned oxidizing agent is an oxidizing liquid.

8. The substrate processing method as described in claim 6, wherein, The aforementioned oxidizing agent is an oxidizing liquid.

9. The substrate processing method as described in claim 1 or 2, wherein, The method includes: after forming the aforementioned doped layer, heating the aforementioned substrate in an atmosphere containing oxygen, thereby repairing oxygen voids in the aforementioned high-dielectric film.

10. The substrate processing method as described in claim 1 or 2, wherein, The method includes: after forming the aforementioned doped layer, irradiating the aforementioned substrate with ultraviolet light in an atmosphere containing oxygen, thereby repairing oxygen voids in the aforementioned high-dielectric film.

11. The substrate processing method as described in claim 1 or 2, wherein, It includes: after forming the aforementioned doped layer, washing the back side of the aforementioned substrate opposite to the aforementioned doped layer or the inclined surface of the aforementioned substrate with a cleaning solution to remove the aforementioned second metal element attached to the aforementioned back side or the aforementioned inclined surface.

12. A substrate processing method, characterized by comprising: preparing a substrate having a high dielectric film having a dielectric constant higher than that of a SiO2 film; forming a doped layer in which a first metal element contained in the high dielectric film is replaced by a second metal element; supplying a metal solution containing the second metal element to the substrate; supplying a polar organic solvent to the substrate; and adsorbing the organic solvent onto the surface of the high dielectric film to form an adsorbed layer containing the organic solvent.

13. The substrate processing method as described in claim 12, wherein, The aforementioned organic solvent contains carbonyl compounds or amine compounds.

14. The substrate processing method according to any one of claims 1, 2, 12, and 13, wherein, The aforementioned high-dielectric film includes a zirconium oxide film or a hafnium oxide film.

15. The substrate processing method according to any one of claims 1, 2, 12, and 13, wherein, The aforementioned high-dielectric film is formed on the first electrode, and the second electrode is formed on the aforementioned high-dielectric film.

16. A substrate processing apparatus, characterized in that it comprises: a substrate holding section for holding a substrate having a high dielectric film having a dielectric constant higher than that of a SiO2 film; and a liquid supply section for supplying a metal solution containing a second metal element (the second metal element having a higher cathode or a lower valence than the first metal element contained in the high dielectric film) to the substrate, and forming a doped layer on the surface of the high dielectric film in which the first metal element is replaced by the second metal element.

17. A substrate processing apparatus for performing the substrate processing method of claim 12, the substrate processing apparatus being characterized by comprising: a substrate holding section for holding a substrate having a high dielectric film having a dielectric constant higher than that of a SiO2 film; and an organic solvent supply section for supplying a polar organic solvent to the substrate, thereby adsorbing the organic solvent onto the surface of the high dielectric film to form an adsorption layer containing the organic solvent.

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