JP2019220514A - Substrate processing method and substrate processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately etch a processed region on one main surface of a substrate while protecting a peripheral portion with an oxidizing liquid. SOLUTION: In a substrate processing apparatus, an oxidizing liquid 82 that oxidizes an upper surface 91 of a substrate 9 is discharged from a nozzle toward a rotating substrate 9 to supply the oxidizing liquid 82 to a peripheral edge portion 93 of the upper surface 91. The step of supplying the etching solution 81 to the processing region 95 located inside the peripheral edge portion 93 on the upper surface 91 by discharging the etching solution 81 for etching the upper surface 91 from the nozzle toward the rotating substrate 9. Will be done. As a result, the treated region 95 can be appropriately etched on the upper surface 91 while protecting the peripheral portion 93 with the oxidizing liquid 82. [Selection diagram] Fig. 4

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus.

  2. Description of the Related Art Conventionally, in a manufacturing process of a semiconductor substrate (hereinafter, simply referred to as “substrate”), various processes are performed on a surface of the substrate. For example, in Patent Literature 1, pure water, which is an etching inhibitor, is supplied near the periphery of the lower surface of the substrate while supplying a chemical solution for etching near the periphery of the upper surface of the rotating substrate. Part of the pure water goes over the edge of the substrate to the upper surface of the substrate due to surface tension and collides with the chemical solution. As a result, the chemical solution is diluted at the portion where the pure water collides with the chemical solution, and the etching rate can be reduced at the portion.

JP-A-2006-139743

  By the way, in the method of Patent Document 1, since the etching rate is merely reduced by diluting the chemical solution with pure water at the peripheral portion of the upper surface, the peripheral portion may be etched more than expected. When the peripheral portion is etched, a problem may occur in the transfer of the substrate and the like in a subsequent process. Therefore, there is a need for a new method capable of appropriately etching the processing region located inside the peripheral portion while protecting the peripheral portion.

  The present invention has been made in view of the above problems, and has as its object to appropriately etch a processing region while protecting a peripheral portion.

  The invention according to claim 1 is a substrate processing method, comprising: a) rotating a disk-shaped substrate in a horizontal state while oxidizing an oxidizing solution for oxidizing one main surface of the substrate toward the substrate; Supplying the oxidizing solution to the peripheral portion of the one main surface by discharging from a nozzle; and b) etching the first main surface while rotating the substrate in a horizontal state, Supplying the etching liquid to a processing region located inside the peripheral portion on the one main surface by discharging the liquid from a nozzle toward the substrate.

  The invention according to claim 2 is the substrate processing method according to claim 1, wherein, in the step a), the nozzle is located on the other main surface side of the substrate toward the other main surface. The oxidizing liquid is discharged, and the oxidizing liquid is supplied to the peripheral portion of the one main surface via the outer peripheral end surface of the rotating substrate.

  According to a third aspect of the present invention, in the substrate processing method according to the second aspect, in the step a), the nozzle is positioned from the nozzle located on the other main surface side toward a central portion of the other main surface. Thus, the oxidizing liquid is discharged.

  The invention according to claim 4 is the substrate processing method according to claim 2 or 3, wherein the steps a) and b) are performed simultaneously, and in the step b), the one main surface of the substrate is provided. The etching liquid is discharged from the nozzle located on the side toward the processing region.

  The invention according to claim 5 is the substrate processing method according to claim 4, wherein the etching liquid discharged to the one main surface and the oxidizing liquid discharged to the other main surface are formed. Both are heated.

  The invention according to claim 6 is the substrate processing method according to claim 4 or 5, wherein a radius of the substrate is 150 mm, and a rotation speed of the substrate in the steps a) and b) is 50 to 50. It is 300 rpm.

  The invention according to claim 7 is the substrate processing method according to any one of claims 1 to 6, wherein a plurality of first material films formed of a first material and the first material are A stacked film including a plurality of second material films formed of different second materials is provided in the processing region on the one main surface of the substrate, and before the step b), in a thickness direction. Is formed in the laminated film, and in the step b), the plurality of second material films included in the laminated film are selectively etched through the hole.

  The invention according to claim 8 is the substrate processing method according to any one of claims 1 to 7, wherein the etching solution has alkalinity.

  The invention according to claim 9 is a substrate processing apparatus, comprising: a substrate holding unit that holds a disk-shaped substrate in a horizontal state; and a substrate rotation unit that rotates the substrate holding unit about a central axis that faces in a vertical direction. A mechanism and an oxidizing solution supply unit that supplies the oxidizing solution to a peripheral portion of the one main surface by discharging an oxidizing solution for oxidizing one main surface of the substrate from a nozzle toward the rotating substrate. Supplying an etching solution for etching the one main surface from a nozzle toward the rotating substrate to a processing region located inside the peripheral portion on the one main surface. And an etching liquid supply unit.

  According to the present invention, the processing region can be appropriately etched on one main surface of the substrate while protecting the peripheral portion with the oxidizing liquid.

FIG. 2 is a diagram illustrating a configuration of a substrate processing apparatus. FIG. 3 is a diagram illustrating the vicinity of a peripheral portion of a substrate. It is a figure showing the flow which processes a substrate. It is a figure for explaining processing of a substrate. It is a figure for explaining processing of a substrate. It is a figure showing other examples of a substrate. It is a figure for explaining processing of a substrate. It is a figure for explaining processing of a substrate. It is a figure showing other examples of a substrate processing device.

  FIG. 1 is a diagram showing a configuration of a substrate processing apparatus 1 according to one embodiment of the present invention. The substrate processing apparatus 1 is a single-wafer processing apparatus that processes a disk-shaped substrate 9 one by one. The substrate processing apparatus 1 includes a substrate holding unit 21, a substrate rotating mechanism 22, a cup 23, an etching liquid supply unit 3, and an oxidizing liquid supply unit 4.

  The substrate holding part 21 has a disk-shaped base part 211 centered on a central axis J1 pointing in the vertical direction. A plurality of chuck pins 212 are provided on the upper surface of the base portion 211. The plurality of chuck pins 212 are arranged at regular intervals in the circumferential direction on the circumference around the center axis J1. When the substrate holding unit 21 holds the substrate 9, the plurality of chuck pins 212 are pressed against the outer peripheral edge of the substrate 9. Thereby, the substrate 9 is held in a horizontal state above the base portion 211. The center of the substrate 9 held by the substrate holding unit 21 is located on the center axis J1. The upper surface of the base portion 211 is parallel to a main surface 92 (hereinafter, referred to as a “lower surface 92”) that faces downward of the substrate 9, and both oppose each other with a gap.

  One end of a shaft portion 221 centered on the central axis J1 is fixed to the center of the lower surface of the base portion 211. When the substrate rotation mechanism 22 having a motor rotates the other end of the shaft portion 221, the substrate holding portion 21 rotates about the central axis J1 together with the substrate 9. The cup 23 has a substantially cylindrical shape surrounding the periphery of the base portion 211. In the processing of the substrate 9 described later, various processing liquids scattered from the outer peripheral edge of the rotating substrate 9 are received by the inner peripheral surface of the cup 23 and collected. In the substrate processing apparatus 1, the upper portion of the cup 23 can be moved up and down by a cup lifting mechanism (not shown). When loading and unloading the substrate 9 to and from the substrate processing apparatus 1, the upper portion of the cup 23 is lowered to prevent the cup 23 from interfering with an external transport mechanism.

  The oxidizing solution supply unit 4 includes a lower nozzle 41 and an oxidizing solution supply source 42. The lower nozzle 41 extends in the up-down direction. A hollow portion extending in the vertical direction is provided on the central axis J1 in the base portion 211 and the shaft portion 221, and the lower nozzle 41 is disposed in the hollow portion. The upper end surface of the lower nozzle 41 is arranged near the upper surface of the base portion 211. The lower nozzle 41 is located on the lower surface 92 side of the substrate 9 held by the substrate holding unit 21. The upper end surface of the lower nozzle 41 directly faces the lower surface 92 of the substrate 9. An oxidizing liquid supply source 42 is connected to the lower end of the lower nozzle 41 via a valve, and the oxidizing liquid supply source 42 supplies the oxidizing liquid to the lower nozzle 41. The oxidizing liquid is discharged upward from a discharge port provided at the center of the upper end surface of the lower nozzle 41. That is, the oxidizing liquid is discharged from the lower nozzle 41 toward the center of the lower surface 92 of the substrate 9. Details of the oxidizing solution will be described later.

  A chemical liquid supply source 43 and a rinse liquid supply source 44 are further connected to the lower nozzle 41 via a valve. By supplying the chemical from the chemical supply source 43 to the lower nozzle 41, the chemical is discharged from the lower nozzle 41 toward the center of the lower surface 92 of the substrate 9. When the rinsing liquid is supplied from the rinsing liquid supply source 44 to the lower nozzle 41, the rinsing liquid is discharged from the lower nozzle 41 toward the center of the lower surface 92. In the substrate processing apparatus 1, the lower nozzle 41 and the chemical liquid supply source 43 constitute a lower surface chemical liquid supply unit, and the lower nozzle 41 and the rinse liquid supply source 44 constitute a lower surface rinse liquid supply unit. The lower nozzle 41 is shared by the oxidizing liquid supply unit 4, the lower chemical liquid supply unit, and the lower rinse liquid supply unit. One or both of the lower surface chemical liquid supply unit and the lower surface rinse liquid supply unit may have a separate nozzle from the lower nozzle 41.

  The etching liquid supply unit 3 includes an upper nozzle 31 and an etching liquid supply source 32. The upper nozzle 31 extends vertically. The upper nozzle 31 is located on the main surface 91 (hereinafter, referred to as “upper surface 91”) facing the substrate 9. Specifically, the upper nozzle 31 is arranged above a central portion of the upper surface 91. The lower end surface of the upper nozzle 31 directly faces the upper surface 91. An etchant supply source 32 is connected to the upper end of the upper nozzle 31 via a valve, and the etchant is supplied from the etchant supply source 32 to the upper nozzle 31. The etching liquid is discharged downward from a discharge port provided at the center of the lower end surface of the upper nozzle 31. That is, the etching liquid is discharged from the upper nozzle 31 toward the center of the upper surface 91 of the substrate 9. Details of the etching solution will be described later.

  A chemical solution supply source 33 and a rinse solution supply source 34 are further connected to the upper nozzle 31 via a valve. When the chemical liquid is supplied from the chemical liquid supply source 33 to the upper nozzle 31, the chemical liquid is discharged from the upper nozzle 31 toward the center of the upper surface 91 of the substrate 9. When the rinsing liquid is supplied from the rinsing liquid supply source 34 to the upper nozzle 31, the rinsing liquid is discharged from the upper nozzle 31 toward the center of the upper surface 91. In the substrate processing apparatus 1, the upper nozzle 31 and the chemical liquid supply source 33 constitute an upper surface chemical liquid supply unit, and the upper nozzle 31 and the rinse liquid supply source 34 constitute an upper surface rinse liquid supply unit. The upper nozzle 31 is shared by the etching liquid supply unit 3, the upper chemical liquid supply unit and the upper rinse liquid supply unit. One or both of the upper surface chemical liquid supply unit and the upper surface rinse liquid supply unit may have a nozzle separate from the upper nozzle 31. Further, the chemical liquid supply source 33 may also serve as the chemical liquid supply source 43, and the rinsing liquid supply source 34 may also serve as the rinsing liquid supply source 44.

  The substrate processing apparatus 1 further includes an organic solvent supply unit 5. The organic solvent supply unit 5 includes an auxiliary nozzle 51 and an organic solvent supply source 52. The auxiliary nozzle 51 is arranged above the substrate 9. An organic solvent supply source 52 is connected to the auxiliary nozzle 51 via a valve. When the organic solvent is supplied from the organic solvent supply source 52 to the auxiliary nozzle 51, the organic solvent is discharged from the auxiliary nozzle 51 toward the center of the upper surface 91 of the substrate 9. In the substrate processing apparatus 1, a nozzle moving mechanism that moves each of the upper nozzle 31 and the auxiliary nozzle 51 may be provided. The nozzle moving mechanism selectively arranges the upper nozzle 31 and the auxiliary nozzle 51 at a facing position facing the upper surface 91 of the substrate 9 and a standby position horizontally separated from the substrate 9. The nozzle moving mechanism may move the upper nozzle 31 and the auxiliary nozzle 51 individually.

  FIG. 2 is a view showing the vicinity of the peripheral portion 93 of the substrate 9 and shows a cross section of the substrate 9 on a plane including the central axis J1. The substrate 9 includes a substrate body 90 and a thin film 911. The thin film 911 is formed of a predetermined material (for example, amorphous silicon) on the upper surface of the substrate main body 90, and covers the entire upper surface. The upper surface 91 of the substrate 9 is the surface of the thin film 911. The lower surface 92 of the substrate 9 is the lower surface of the substrate main body 90. A thin film may be formed on the lower surface 92. The thin film 911 is also provided on a part of the outer peripheral end surface 94 (so-called bevel surface) of the substrate 9. The above-described peripheral portion 93 is an annular portion of the substrate 9 including the outer peripheral end surface 94 and the vicinity thereof. In the container storing the substrate 9, the substrate 9 is held in a state in which the peripheral portion 93 of the substrate 9 is in contact with the holding portion of the container, and a portion inside the peripheral portion 93 is not in contact with any member. .

Here, the etchant used in the substrate processing apparatus 1 is capable of etching the thin film 911, and includes TMY (trimethyl-2-hydroxyethylammonium hydroxide), TMAH (tetramethylammonium hydroxide), and ammonia. An etching solution having alkalinity such as water (NH ₄ OH) is exemplified. In this embodiment, an aqueous solution of TMY is used as an etching solution. An acidic etchant may be used. The oxidizing solution used in the substrate processing apparatus 1 is capable of oxidizing the thin film 911 (that is, forming an oxide film), and includes hydrogen peroxide solution (H ₂ O ₂ ), ammonia water, and the like. A mixed solution of hydrogen peroxide solution, ozone water and the like are exemplified. In this embodiment, a hydrogen peroxide solution is used as the oxidizing solution.

  FIG. 3 is a diagram showing a flow in which the substrate processing apparatus 1 processes the substrate 9. In the substrate processing apparatus 1 of FIG. 1, the substrate 9 to be processed is loaded in advance by an external transport mechanism and held by the substrate holding unit 21. In the processing of the substrate 9, first, the rotation of the substrate 9 is started by the substrate rotation mechanism 22 (Step S11). The substrate 9 rotates together with the substrate holding unit 21 in a horizontal state. In addition, a chemical solution is supplied to the center of the upper surface 91 of the substrate 9 by the upper chemical solution supply unit via the upper nozzle 31 arranged at the opposing position, and the central portion of the lower surface 92 via the lower nozzle 41 by the lower chemical solution supply unit. Is supplied with a chemical solution (step S12).

  On the upper surface 91 and the lower surface 92, the chemical liquid spreads toward the outer peripheral edge of the substrate 9 by the rotation of the substrate 9, and the chemical liquid is supplied to the entire upper surface 91 and lower surface 92. The chemical liquid scattered from the outer peripheral edge of the substrate 9 is received and collected by the inner peripheral surface of the cup 23 (the same applies when a rinsing liquid, an oxidizing liquid, and an etching liquid described later are supplied). The chemical is, for example, DHF (dilute hydrofluoric acid), and the supply of the chemical removes the natural oxide film on the upper surface 91 and the lower surface 92. In the substrate processing apparatus 1, other types of chemicals may be used.

  When the discharge of the chemical is continued for a predetermined time, the discharge of the chemical is stopped. Subsequently, the rinsing liquid is supplied to the center of the upper surface 91 via the upper nozzle 31 by the upper surface rinsing liquid supply unit, and the rinsing liquid is supplied to the center of the lower surface 92 via the lower nozzle 41 by the lower surface rinsing liquid supply unit. It is supplied (step S13). On the upper surface 91 and the lower surface 92, the rinsing liquid spreads toward the outer peripheral edge of the substrate 9 by the rotation of the substrate 9, and the rinsing liquid is supplied to the entire upper surface 91 and the lower surface 92. The rinsing liquid is, for example, pure water, and the supply of the rinsing liquid removes the chemical liquid attached to the upper surface 91 and the lower surface 92. In the substrate processing apparatus 1, a rinsing liquid other than pure water may be used. The discharge of the rinsing liquid is continued for a predetermined time and then stopped.

  Subsequently, the oxidizing liquid supply source 42 supplies the oxidizing liquid to the lower nozzle 41, whereby the oxidizing liquid is continuously discharged from the lower nozzle 41 toward the center of the lower surface 92 (Step S14). The etching liquid supply source 32 supplies the etching liquid to the upper nozzle 31, whereby the etching liquid is continuously discharged from the upper nozzle 31 toward the center of the upper surface 91 (Step S15). In this processing example, the discharge of the oxidizing liquid from the lower nozzle 41 and the discharge of the etching liquid from the upper nozzle 31 are started almost simultaneously.

  At this time, on the lower surface 92, the oxidizing liquid spreads toward the outer peripheral edge of the substrate 9 due to the rotation of the substrate 9, and the oxidizing liquid is supplied to the entire lower surface 92. The substrate main body 90 is formed of a non-oxide (for example, silicon), and a uniform oxide film is formed on the entire lower surface 92 by an oxidation reaction with an oxidizing solution. At the outer periphery, a part of the oxidizing solution is scattered. Another part of the oxidizing solution adheres to the outer peripheral end surface 94 due to surface tension and reaches the peripheral portion 93 of the upper surface 91. In other words, the oxidizing liquid discharged from the lower nozzle 41 toward the lower surface 92 is supplied to the peripheral portion 93 of the upper surface 91 via the outer peripheral end surface 94.

  On the upper surface 91, the etching liquid spreads toward the outer peripheral edge of the substrate 9 due to the rotation of the substrate 9. As described above, the oxidizing liquid exists on the peripheral portion 93 of the upper surface 91. Therefore, as shown in FIG. 4, the etching solution 81 and the oxidizing solution 82 are mixed at the peripheral portion 93 of the upper surface 91. FIG. 4 schematically shows the etching liquid 81 and the oxidizing liquid 82 in the vicinity of the peripheral portion 93, and a reference numeral 83 is attached to a portion where the etching liquid 81 and the oxidizing liquid 82 are mixed. At the peripheral portion 93 of the upper surface 91, the etching of the substrate 9 (here, the etching of the thin film 911) is suppressed by mixing the oxidizing liquid 82 with the etching liquid 81. Although the reason why the etching of the substrate 9 is suppressed by mixing the etching solution 81 and the oxidizing solution 82 is not clear, the upper surface 91 is microscopically oxidized by the oxidizing solution 82 (a microscopic oxide film is formed). This is considered to be due to protection from the etching solution 81. When hydrogen peroxide solution is used as the oxidizing solution 82, the concentration of hydrogen peroxide in the oxidizing solution 82 is, for example, 8% by weight or more, preferably 15% by weight, in order to more reliably suppress the etching at the peripheral portion 93. % Or more.

  On the other hand, the thin film 911 is etched by the etching liquid 81 in a region 95 (hereinafter, referred to as a “processing region 95”) inside the peripheral portion 93 on the upper surface 91. FIG. 5 shows the substrate 9 in which the thin film 911 is etched in the processing region 95, and the illustration of the etching solution 81 and the oxidizing solution 82 is omitted. In the substrate processing apparatus 1, the oxidizing liquid 82 discharged from the lower nozzle 41 toward the lower surface 92 while appropriately etching the processing region 95 with the etching liquid discharged from the upper nozzle 31 toward the processing region 95 on the upper surface 91. Thereby, the peripheral portion 93 of the upper surface 91 can be protected (the etching rate is sufficiently reduced or the etching is prevented). Actually, the outer peripheral end surface 94 (bevel surface) of the substrate 9 is also protected by the oxidizing liquid 82.

  In the preferred substrate processing apparatus 1, the etching liquid supply source 32 has a heater, and the etching liquid 81 heated to a predetermined temperature (for example, 85 ° C.) is discharged onto the upper surface 91. Thus, in the processing region 95, the thin film 911 is etched at a relatively high etching rate. More preferably, oxidizing solution supply source 42 has a heater, and oxidizing solution 82 heated to a predetermined temperature (for example, 70 ° C.) is discharged to lower surface 92. Accordingly, the high temperature state of the etching liquid 81 is easily maintained, and the etching rate of the processing region 95 can be further increased. The high-temperature oxidizing liquid 82 is generated, for example, by mixing high-temperature pure water and normal-temperature hydrogen peroxide. Similarly, the high-temperature etching solution 81 may be generated by mixing high-temperature pure water with room-temperature TMY or the like.

  Conditions for allowing the oxidizing liquid 82 discharged from the lower nozzle 41 toward the lower surface 92 to reach the peripheral portion 93 of the upper surface 91 are appropriately determined according to the radius of the substrate 9, the type of the oxidizing liquid 82, and the like. In one example, when the radius of the substrate 9 is 150 mm and the oxidizing liquid 82 is discharged from the lower nozzle 41 at a flow rate of 1 to 2 L / min, the rotation speed of the substrate 9 is set to, for example, 50 to 300 rpm. You. Thus, the oxidizing liquid 82 can appropriately reach the peripheral portion 93 of the upper surface 91. In the substrate processing apparatus 1, as the rotation speed of the substrate 9 decreases, the width of the region of the upper surface 91 where the oxidizing liquid 82 reaches from the outer peripheral end surface 94 (the radial width inward from the outer peripheral end surface 94; The average value of “the width in the region”) increases, and the variation in the width in the circumferential direction also increases. Therefore, from the viewpoint of reducing the variation in the width while securing a certain width (for example, 1 to 3 mm) in the mixed region, the rotation speed of the substrate 9 is preferably set to 100 to 200 rpm. More preferably, the rotation speed of the substrate 9 is 150 to 200 rpm.

  When the discharge of the oxidizing liquid 82 and the etching liquid 81 is continued for a predetermined time, the discharge of both is stopped. Subsequently, the rinsing liquid is supplied to the center of the upper surface 91 via the upper nozzle 31 by the upper surface rinsing liquid supply unit, and the rinsing liquid is supplied to the center of the lower surface 92 via the lower nozzle 41 by the lower surface rinsing liquid supply unit. It is supplied (step S16). On the upper surface 91 and the lower surface 92, the rinsing liquid spreads toward the outer peripheral edge of the substrate 9 by the rotation of the substrate 9, and the rinsing liquid is supplied to the entire upper surface 91 and the lower surface 92. By supplying the rinsing liquid, the etching liquid 81 adhering to the upper surface 91 and the oxidizing liquid 82 adhering to the lower surface 92 are removed. The discharge of the rinsing liquid is continued for a predetermined time and then stopped.

  Subsequently, the organic solvent is supplied to the center of the upper surface 91 by the organic solvent supply unit 5 via the auxiliary nozzle 51 disposed at the opposing position (Step S17). On the upper surface 91, the rotation of the substrate 9 causes the organic solvent to spread toward the outer peripheral edge of the substrate 9, and the entire upper surface 91 is supplied with the organic solvent. The organic solvent is, for example, IPA (isopropyl alcohol), and the rinsing liquid on the upper surface 91 is replaced with the organic solvent. In the substrate processing apparatus 1, an organic solvent other than IPA may be used. The discharge of the organic solvent is continued for a predetermined time, and then stopped.

  When the supply of the organic solvent is completed, the substrate rotation mechanism 22 sets the rotation speed of the substrate 9 higher than that at the time of supplying the processing liquid (that is, the chemical liquid, the rinsing liquid, the oxidizing liquid, the etching liquid, and the organic solvent). 9 (spin drying) is started (step S18). When the drying process is completed, the rotation of the substrate 9 is stopped (Step S19). The substrate 9 is carried out of the substrate processing apparatus 1 by an external transport mechanism. Thus, the processing of the substrate 9 in the substrate processing apparatus 1 is completed.

  In the above processing example, for the sake of simplicity, the case where the thin film 911 is removed in the processing region 95 on the upper surface 91 of the substrate 9 and the thin film 911 is left in the peripheral portion 93 has been described. May be used in various processes for.

  FIG. 6 is a diagram illustrating another example of the substrate. In the substrate 9a of FIG. 6, a laminated film 912 is formed on the upper surface of the substrate main body 90 inside the peripheral portion 93. That is, the stacked film 912 is provided in the processing region 95 on the upper surface 91. The stacked film 912 includes a plurality of first material films 913 formed of a first material, and a plurality of second material films 914 formed of a second material different from the first material. The first material films 913 and the second material films 914 are provided alternately in the thickness direction (stacking direction). For example, the first material film 913 is an insulating film such as a silicon oxide film. The first material film 913 may be a material having a sufficiently low etching rate with an etchant (a material that is hardly etched), and may be a silicon nitride film, TEOS (tetraethoxysilane), or the like. The second material film 914 is a polysilicon film. The second material film 914 may be a film made of another material having a relatively high etching rate by an etchant.

  On the other hand, the laminated film 912 is not formed on the surface of the peripheral portion 93 on the upper surface of the substrate main body 90. The surface of the peripheral portion 93 of the upper surface 91 of the substrate 9 a is the surface of the substrate main body 90. The substrate main body 90 is formed of a non-oxide (for example, silicon), and the etching rate of the substrate main body 90 with an etchant is relatively high. Further, the surface of the substrate body 90 can be oxidized by the oxidizing liquid. The peripheral portion 93 of the upper surface 91 may be a film surface of a material that can be etched by an etching solution and oxidized by an oxidizing solution, such as the second material film 914. The lower surface 92 of the substrate 9a is the lower surface of the substrate main body 90. The lower surface 92 of the substrate 9a may be the surface of a thin film formed on the lower surface of the substrate main body 90.

  When the substrate processing apparatus 1 processes the substrate 9a, a plurality of holes 915 extending in the thickness direction with respect to the laminated film 912 are formed in advance by an external device, as shown in FIG. Each hole 915 penetrates the plurality of first material films 913 and the plurality of second material films 914. The formation of the holes 915 is performed by, for example, reactive ion etching.

  In the processing of the substrate 9a in the substrate processing apparatus 1, the supply of the chemical liquid to the upper surface 91 and the lower surface 92 and the supply of the rinsing liquid to the upper surface 91 and the lower surface 92 are sequentially performed while rotating the substrate 9a, as described above. (FIG. 3: steps S11 to S13). Subsequently, the discharge of the oxidizing liquid from the lower nozzle 41 to the center of the lower surface 92 and the discharge of the etchant from the upper nozzle 31 to the center of the upper surface 91 are started almost simultaneously (steps S14 and S15).

  On the lower surface 92, the oxidizing liquid spreads toward the outer peripheral edge of the substrate 9a due to the rotation of the substrate 9a, and an oxide film is formed. A part of the oxidizing solution is supplied to the peripheral portion 93 of the upper surface 91 via the outer peripheral end surface 94 (see FIG. 4). On the upper surface 91, the etching liquid spreads toward the outer peripheral edge of the substrate 9a due to the rotation of the substrate 9a. At the peripheral portion 93 of the upper surface 91, etching is suppressed by mixing the etching solution and the oxidizing solution.

  In the processing region 95 on the upper surface 91, the second material film 914 is selectively etched by the etching solution that has entered the holes 915. The first material film 913 is hardly etched by the etchant. As a result, as shown in FIG. 8, the second material film 914 recedes from the inner peripheral surface of the hole 915. In other words, a structure in which the first material film 913 protrudes inward from the inner peripheral surface of the widened hole 915 is obtained. If an oxidizing solution adheres to the surface of the second material film 914 in the hole 915, the surface of the second material film 914 is oxidized. It can be said that the processing region 95 is also a processing liquid that can be oxidized.

  The discharge of the oxidizing liquid and the etching liquid is continued for a predetermined time, and then stopped. Subsequently, the supply of the rinsing liquid to the upper surface 91 and the lower surface 92 and the supply of the organic solvent to the upper surface 91 are sequentially performed (Steps S16 and S17). After the substrate 9a is dried at high speed, the rotation of the substrate 9a is stopped (Steps S18 and S19), and the processing of the substrate 9a in the substrate processing apparatus 1 is completed.

  In the processing of the substrate 9a on which the laminated film 912 is provided, it takes a long time to selectively etch the second material film 914 through the hole 915. Therefore, if the processing is performed without supplying the oxidizing solution, the etching amount in the peripheral portion 93 of the upper surface 91 increases (for example, the etching amount becomes several tens μm with respect to the original thickness of 775 μm). This causes a problem in the transfer of the substrate 9a in the subsequent process.

  On the other hand, in the substrate processing apparatus 1, by protecting the peripheral portion 93 of the upper surface 91 with the oxidizing liquid, the peripheral portion 93 is suppressed from being etched in the selective etching of the second material film 914 which requires a long time. can do. As a result, it is possible to prevent the above-described problem from occurring. Since the thickness of the oxide film formed on the lower surface 92 of the substrate 9a and the peripheral portion 93 of the upper surface 91 is several nm, there is no problem in transporting the substrate 9a or the like, and it is necessary to remove the oxide film. Absent. In the above process, the outer peripheral end surface 94 (bevel surface) of the substrate 9a is also protected by the oxidizing solution, so that the diameter of the substrate 9a is prevented from being reduced.

  FIG. 9 is a diagram illustrating another example of the substrate processing apparatus. In the substrate processing apparatus 1a of FIG. 9, the configuration of the oxidizing solution supply unit 4a is different from that of the substrate processing apparatus 1 of FIG. Other configurations are the same as those of the substrate processing apparatus 1 of FIG. 1, and the same components are denoted by the same reference numerals.

  The oxidizing solution supply unit 4a includes an oxidizing solution nozzle 41a located on the upper surface 91 side of the substrate 9. The oxidizing liquid nozzle 41a extends in the up-down direction, and is supported to be inclined with respect to the up-down direction so that the lower end surface where the discharge port is formed is located radially outside the upper end surface. . Further, the discharge port of the oxidizing liquid nozzle 41a faces the vicinity of the peripheral portion 93 of the upper surface 91. The oxidizing liquid is discharged from the oxidizing liquid nozzle 41a toward the peripheral portion 93 of the upper surface 91. The discharge direction of the oxidizing liquid from the oxidizing liquid nozzle 41a is directed downward and radially outward.

  In the substrate processing apparatus 1a, the discharge of the oxidizing liquid from the oxidizing liquid nozzle 41a to the peripheral portion 93 of the upper surface 91 and the discharge of the etching liquid from the upper nozzle 31 to the central portion of the upper surface 91 are started almost simultaneously. In the processing region 95 on the upper surface 91, the thin film 911 (see FIG. 2) is etched by the etchant. At the peripheral portion 93 of the upper surface 91, etching is suppressed by mixing the etching solution and the oxidizing solution. Thus, also in the substrate processing apparatus 1a, it is possible to appropriately etch the processing region 95 while protecting the peripheral portion 93 of the upper surface 91 with the oxidizing liquid. Of course, the substrate 9a in FIG. 6 may be processed in the substrate processing apparatus 1a in FIG.

  As described above, in the processing of the substrates 9 and 9a in the substrate processing apparatuses 1 and 1a, the step of supplying the oxidizing solution to the peripheral portion 93 of the upper surface 91 and the process of etching the processing region 95 located inside the peripheral portion 93 are performed. Supplying the liquid. This realizes appropriate etching of the processing region 95 while protecting the peripheral portion 93 with the oxidizing solution on the upper surfaces 91 of the substrates 9 and 9a.

  By the way, in the substrate processing apparatus 1a of FIG. 9, in the processing of the substrates 9, 9a, the processing area 95 of the upper surface 91 is caused by the splash of the oxidizing liquid discharged from the oxidizing liquid nozzle 41a toward the peripheral portion 93 of the upper surface 91. Oxidizing solution may adhere to the surface. In this case, when a part of the surface of the thin film 911 or the second material film 914 is oxidized, the surface (oxide film surface) is hardly etched by the etchant. On the other hand, in the substrate processing apparatus 1 of FIG. 1, since the oxidizing liquid is discharged from the lower nozzle 41 located on the lower surface 92 side of the substrates 9 and 9a toward the lower surface 92, the oxidizing liquid is discharged toward the substrates 9 and 9a. The oxidizing solution can be prevented from adhering to the processing region 95 on the upper surface 91 due to splashing of the oxidizing solution.

  In the substrate processing apparatuses 1 and 1a, the step of supplying the oxidizing liquid to the peripheral portion 93 of the upper surface 91 and the step of supplying the etching liquid to the processing region 95 located inside the peripheral portion 93 can be individually performed. is there. For example, in the substrate processing apparatus 1 of FIG. 1, the oxidizing liquid is discharged from the lower nozzle 41 toward the lower surface 92 while rotating the substrates 9, 9a. Simultaneously with the discharge of the oxidizing liquid, pure water is discharged from the upper nozzle 31 toward the center of the upper surface 91. Thus, an oxide film is formed on the peripheral portion 93 of the upper surface 91 by the oxidizing solution that has reached via the outer peripheral end surface 94, and the infiltration of the oxidizing solution into the processing region 95 by the pure water is suppressed. After that, the etching liquid is discharged from the upper nozzle 31 toward the center of the upper surface 91. This makes it possible to appropriately etch the processing region 95 while protecting the peripheral portion 93 on the upper surface 91 of the substrates 9 and 9a using the oxide film formed by the oxidizing solution. The same applies to the substrate processing apparatus 1a of FIG. When an oxide film is formed on the peripheral portion 93 of the upper surface 91 before supplying the etching solution to the processing region 95, it can be considered that the peripheral portion 93 is substantially protected by the oxidizing solution. .

  On the other hand, when the step of supplying the oxidizing liquid to the peripheral portion 93 of the upper surface 91 and the step of supplying the etching liquid to the processing region 95 located inside the peripheral portion 93 are performed simultaneously, the processing of the substrates 9 and 9a is performed. It is possible to perform the processing efficiently (that is, to shorten the time required for the processing). Also in this case, the infiltration of the oxidizing solution into the processing region 95 can be suppressed by the etching solution, and the processing region 95 can be appropriately etched.

  Various modifications are possible in the substrate processing and substrate processing apparatuses 1 and 1a.

  In the substrate processing apparatus 1 of FIG. 1, the oxidizing liquid is discharged from the upper nozzle 31 and the etching liquid is discharged from the lower nozzle 41 to protect the peripheral portion 93 of the lower surface 92 with the oxidizing liquid flowing from the upper surface 91 to the lower surface 92. Meanwhile, the processing region located inside the peripheral portion 93 (the processing region on the lower surface 92) may be etched. Similarly, in the substrate processing apparatus 1 a of FIG. 9, the etching liquid may be discharged from the lower nozzle 41 while discharging the oxidizing liquid from the oxidizing liquid nozzle facing the peripheral portion 93 of the lower surface 92.

  As described above, in the substrate processing apparatuses 1 and 1a, the oxidizing solution for oxidizing one main surface of the substrates 9 and 9a is discharged from the nozzle toward the substrates 9 and 9a, thereby forming the peripheral edge of the one main surface. A step of supplying an oxidizing solution to the portion 93 and a step of discharging an etching solution for etching the one main surface from the nozzle toward the substrates 9 and 9a so that the one main surface is positioned inside the peripheral portion 93; And supplying an etchant to the processing region to be processed. Thereby, the processing region can be appropriately etched on the one main surface of the substrates 9, 9a while protecting the peripheral portion 93 with the oxidizing liquid.

  In the substrate processing apparatus 1 of FIG. 1, the lower nozzle 41 may be arranged at a position facing the peripheral edge 93 of the lower surface 92 of the substrates 9, 9a. Also in this case, it is possible to supply the oxidizing liquid to the peripheral portion 93 of the upper surface 91 via the outer peripheral end surface 94 of the rotating substrates 9 and 9a. When the lower surface 92 of the substrates 9 and 9a is oxidized by the oxidizing liquid, from the viewpoint of making the entire lower surface 92 uniform (forming a uniform oxide film), the lower nozzle 41 is directed toward the center of the lower surface 92. It is preferable that the oxidizing liquid is discharged. When an oxide film is formed on the entire lower surface 92, the oxide film can protect the lower surface 92 in a subsequent step.

  The etching liquid does not necessarily need to be discharged toward the center of the upper surface 91, and the etching liquid is directed from the upper nozzle 31 toward the position on the upper surface 91 inside the peripheral portion 93 and outside the center. May be discharged. That is, the processing region where the etching is performed does not necessarily need to include the central portion.

  When neither of the processing liquids is discharged toward the central portion of the lower surface 92 of the substrates 9 and 9a, a substrate holding portion that suction-holds the central portion of the lower surface 92 may be provided.

  The substrate on which processing is performed in the substrate processing apparatuses 1 and 1a is not limited to a semiconductor substrate, and may be another substrate.

  The configurations in the above-described embodiment and each modified example may be appropriately combined as long as they do not conflict with each other.

DESCRIPTION OF SYMBOLS 1, 1a Substrate processing apparatus 3 Etching liquid supply part 4, 4a Oxidation liquid supply part 9, 9a Substrate 21 Substrate holding part 22 Substrate rotation mechanism 31 Upper nozzle 41 Lower nozzle 41a Oxidation liquid nozzle 81 Etching liquid 82 Oxidation liquid 91 (substrate ) Upper surface 92 Lower surface (of substrate) 93 Peripheral portion (of substrate) 94 Outer peripheral end surface (of substrate) 95 Processing area 912 Stacked film 913 First material film 914 Second material film 915 Hole J1 Central axis S11 ~ S19 Step

Claims (9)

A substrate processing method,
a) While rotating the disk-shaped substrate in a horizontal state, an oxidizing solution for oxidizing one main surface of the substrate is discharged from a nozzle toward the substrate, thereby forming a peripheral portion of the one main surface. Supplying the oxidizing solution;
b) While rotating the substrate in a horizontal state, an etching solution for etching the one main surface is discharged from a nozzle toward the substrate, so that the one main surface is positioned inside the peripheral portion on the one main surface. Supplying the etching solution to the processing region;
A substrate processing method comprising: The substrate processing method according to claim 1, wherein
In the step (a), the oxidizing solution is discharged from the nozzle located on the other main surface side of the substrate toward the other main surface, and the oxidizing solution is discharged through an outer peripheral end surface of the rotating substrate. Is supplied to the peripheral portion of the one main surface. 3. The substrate processing method according to claim 2, wherein
In the step (a), the oxidizing solution is discharged from the nozzle located on the other main surface side toward a central portion of the other main surface. The substrate processing method according to claim 2 or 3,
The steps a) and b) are performed simultaneously,
In the step (b), the etching liquid is discharged from the nozzle located on the one main surface side of the substrate toward the processing region. The substrate processing method according to claim 4, wherein
A substrate processing method, wherein both the etching liquid discharged to the one main surface and the oxidizing liquid discharged to the other main surface are heated. The substrate processing method according to claim 4, wherein:
A radius of the substrate is 150 mm,
A substrate processing method, wherein the number of rotations of the substrate in the steps a) and b) is 50 to 300 rpm. The substrate processing method according to any one of claims 1 to 6, wherein
A laminated film including a plurality of first material films formed of a first material and a plurality of second material films formed of a second material different from the first material is provided on the one main surface of the substrate. Is provided in the processing area,
Before the step b), a hole extending in the thickness direction is formed in the laminated film,
The substrate processing method, wherein in the step (b), the plurality of second material films included in the laminated film are selectively etched through the holes. The substrate processing method according to claim 1, wherein:
A substrate processing method, wherein the etching solution has alkalinity. A substrate processing apparatus,
A substrate holding unit for holding the disk-shaped substrate in a horizontal state,
A substrate rotation mechanism that rotates the substrate holding portion about a central axis that faces in the vertical direction,
An oxidizing solution that oxidizes one main surface of the substrate, by discharging the oxidizing solution from a nozzle toward the rotating substrate, to supply the oxidizing solution to a peripheral portion of the one main surface,
An etching solution for etching the one main surface, which is supplied from a nozzle toward the rotating substrate, to supply the etching solution to a processing region located inside the peripheral portion on the one main surface. A liquid supply unit,
A substrate processing apparatus comprising:

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