Substrate processing method and substrate processing apparatus

Abstract

The invention relates to a substrate processing method and a substrate processing apparatus. This substrate processing method is provided with: a step (step S11) in which a substrate having an amorphous silicon layer on the surface of which a metamorphic layer derived from dry etching is formed is held in a horizontal state; a step (step S12) in which the modified layer is modified by irradiating the modified layer with ultraviolet light; and a step (step S13) in which a chemical solution is supplied to the amorphous silicon layer having the modified layer on the surface thereof, and wet etching is performed on the amorphous silicon layer. This makes it possible to efficiently perform wet etching of the amorphous silicon layer.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 202080022833.1 (PCT application number PCT / JP2020 / 000321), whose application date is January 8, 2020 and whose invention name is “Substrate processing method and substrate processing device”. Technical Field

[0002] The present invention relates to a substrate processing method and a substrate processing device. Background Art

[0003] In recent years, as patterns on semiconductor substrates (hereinafter referred to as "substrates") have become increasingly finer, pattern formation using multi-patterning has become increasingly common. In multi-patterning, the top and side surfaces of an intermediate pattern, such as amorphous silicon, formed on a substrate are covered with a coating film such as silicon oxide (SiOx). This coating film on the top surface of the intermediate pattern is removed by anisotropic etching using plasma etching. Furthermore, the intermediate pattern is removed using dry etching, leaving the coating film covering the side surfaces of the intermediate pattern (the so-called sidewalls) as a pattern finer than the intermediate pattern. Subsequently, dry etching is performed using these sidewalls as a mask to form a fine pattern.

[0004] On the other hand, Japanese Patent Application Laid-Open No. 2018-19089 (Document 1) discloses a technology for wet-etching a polycrystalline silicon film on a substrate by supplying a chemical solution containing TMAH (tetramethylammonium hydroxide) to the polycrystalline silicon film.

[0005] However, in the aforementioned multi-patterning process, when the intermediate pattern is removed by dry etching, polymeric residues may remain between the sidewalls, potentially causing pattern formation defects in subsequent film formation and etching steps. Therefore, research is underway to remove the intermediate pattern of amorphous silicon by wet etching, while supplying a chemical solution onto the substrate.

[0006] However, when removing the intermediate pattern of amorphous silicon by wet etching, it is known that the etching rate is much lower than the etching rate in conventional wet etching of amorphous silicon.

[0007] Therefore, after in-depth research, the inventors of the present application obtained the following discovery: during the plasma etching process, which is the pre-process of removing the intermediate pattern of amorphous silicon (i.e., the amorphous silicon layer), oxygen, carbon, etc. are incident on the upper surface of the intermediate pattern exposed from the coating film such as silicon oxide, and the above-mentioned etching rate decreases due to the deterioration of the upper surface caused by this incidence. Summary of the Invention

[0008] Problems to be solved by the invention

[0009] The present invention relates to a substrate processing method, and aims to efficiently perform wet etching of an amorphous silicon layer.

[0010] A preferred embodiment of the present invention provides a substrate processing method comprising the following steps: a) holding a substrate having an amorphous silicon layer with a degraded layer formed on its surface due to dry etching in a horizontal position; b) modifying the degraded layer by irradiating the degraded layer with ultraviolet light to form a modified layer; and c) supplying a chemical solution to the amorphous silicon layer having the modified layer on its surface to wet etch the amorphous silicon layer. This allows for efficient wet etching of the amorphous silicon layer.

[0011] Preferably, in the dry etching, the coating film formed on the surface of the amorphous silicon layer is etched using plasma generated using a fluorocarbon-based gas and an oxygen gas.

[0012] The amorphous silicon layer is preferably an intermediate pattern formed during multiple patterning of the substrate. During the dry etching, the coating film covering the upper surface and side surfaces of the intermediate pattern is anisotropically etched, thereby exposing the upper surface of the intermediate pattern from the coating film and forming sidewalls of the coating film covering the side surfaces of the intermediate pattern. During the wet etching, the intermediate pattern is removed, while the sidewalls remain.

[0013] The wavelength of the ultraviolet rays is preferably 250 nm or less.

[0014] It is preferred that the cumulative irradiation dose of the ultraviolet rays in the step b) is 1000 mJ / cm 2 above.

[0015] The irradiation with ultraviolet rays in the step b) is preferably performed in a low-oxygen atmosphere.

[0016] Preferably, in step b), the ultraviolet irradiation area on the substrate is scanned, and the cumulative ultraviolet irradiation amount for the thicker area of the altered layer in the amorphous silicon layer is greater than the cumulative ultraviolet irradiation amount for the thinner area of the altered layer.

[0017] Preferably, in step c), the discharge position of the chemical solution on the substrate is scanned. The discharge time of the chemical solution in the thick modified layer region of the amorphous silicon layer is longer than that in the thin modified layer region.

[0018] Preferably, the substrate processing method further comprises, between the step b) and the step c), a step of supplying another chemical solution to the amorphous silicon layer to remove a natural oxide film on the surface of the amorphous silicon layer.

[0019] The present invention also relates to a substrate processing apparatus. A preferred embodiment of the present invention comprises: a substrate holding unit that holds a substrate having an amorphous silicon layer with a degraded layer formed on its surface due to dry etching in a horizontal position; an ultraviolet irradiation unit that modifies the degraded layer by irradiating ultraviolet light onto the degraded layer to form a modified layer; and a chemical liquid supply unit that supplies a chemical liquid to the amorphous silicon layer having the modified layer on its surface to wet etch the amorphous silicon layer. This enables efficient wet etching of the amorphous silicon layer.

[0020] In the dry etching, the coating film formed on the surface of the amorphous silicon layer is preferably etched using plasma generated using a fluorocarbon-based gas and an oxygen gas.

[0021] The amorphous silicon layer is preferably an intermediate pattern formed during multiple patterning of the substrate. During the dry etching, the coating film covering the upper surface and side surfaces of the intermediate pattern is anisotropically etched, thereby exposing the upper surface of the intermediate pattern from the coating film and forming sidewalls of the coating film covering the side surfaces of the intermediate pattern. During the wet etching, the intermediate pattern is removed, while the sidewalls remain.

[0022] The wavelength of the ultraviolet rays is preferably 250 nm or less.

[0023] Preferably, the cumulative irradiation dose of the ultraviolet rays to the amorphous silicon layer is 1000 mJ / cm 2 above.

[0024] It is preferable that the ultraviolet irradiation on the amorphous silicon layer is performed in a low-oxygen atmosphere.

[0025] The substrate processing apparatus preferably further includes an irradiation control unit for controlling the ultraviolet irradiation unit. The ultraviolet irradiation unit includes an ultraviolet lamp for irradiating the substrate with ultraviolet rays, and an irradiation area scanning mechanism for scanning an irradiation area of the substrate with the ultraviolet rays. The irradiation control unit controls at least one of the ultraviolet lamp and the irradiation area scanning mechanism so that the cumulative irradiation amount of the ultraviolet rays in the thick degenerate layer region of the amorphous silicon layer is greater than the cumulative irradiation amount of the ultraviolet rays in the thin degenerate layer region.

[0026] The substrate processing apparatus preferably further includes a supply control unit for controlling the chemical liquid supply unit. The chemical liquid supply unit includes a chemical liquid discharge unit for discharging the chemical liquid toward the substrate, and a discharge position scanning mechanism for scanning a discharge position of the chemical liquid on the substrate. The supply control unit controls the discharge position scanning mechanism so that the chemical liquid discharge time for a region of the amorphous silicon layer where the modified layer is thick is longer than the chemical liquid discharge time for a region where the modified layer is thin.

[0027] Preferably, the substrate processing apparatus further includes another chemical solution supply unit configured to supply another chemical solution to the amorphous silicon layer between the irradiation of the amorphous silicon layer with ultraviolet rays and the supply of the chemical solution to remove a natural oxide film on the surface of the amorphous silicon layer.

[0028] More specifically, the present invention relates to the following items.

[0029] <1> A substrate processing method comprising the following steps:

[0030] a) holding a substrate having an amorphous silicon layer on the surface of which a degenerate layer due to dry etching is formed in a horizontal state;

[0031] b) a step of modifying the deteriorated layer by irradiating the deteriorated layer with ultraviolet rays to form a modified layer; and

[0032] c) a step of supplying a chemical solution to the amorphous silicon layer having the modified layer on the surface thereof to wet-etch the amorphous silicon layer.

[0033] <2> ,according to <1> The substrate processing method, wherein:

[0034] In the dry etching, the coating film formed on the surface of the amorphous silicon layer is etched using plasma generated using a fluorocarbon-based gas and an oxygen gas.

[0035] <3> ,according to <2> The substrate processing method, wherein:

[0036] The amorphous silicon layer is an intermediate pattern formed in the middle of multiple patterning of the substrate.

[0037] In the dry etching, the coating film covering the upper surface and side surfaces of the intermediate pattern is anisotropically etched, thereby exposing the upper surface of the intermediate pattern from the coating film and forming side walls of the coating film covering the side surfaces of the intermediate pattern.

[0038] In the wet etching, the intermediate pattern is removed while the sidewall remains.

[0039] <4> ,according to <1> to <3> The substrate processing method according to any one of the preceding claims, wherein:

[0040] The wavelength of the ultraviolet rays is 250 nm or less.

[0041] <5> ,according to <1> to <4> The substrate processing method according to any one of the preceding claims, wherein:

[0042] The cumulative irradiation dose of the ultraviolet rays in the step b) is 1000 mJ / cm 2 above.

[0043] <6> ,according to <1> to <5> The substrate processing method according to any one of the preceding claims, wherein:

[0044] The ultraviolet ray irradiation in the step b) is performed in a low-oxygen atmosphere.

[0045] <7> ,according to <1> to <6> The substrate processing method according to any one of the preceding claims, wherein:

[0046] In the step b), the ultraviolet irradiation area on the substrate is scanned.

[0047] In the amorphous silicon layer, a cumulative irradiation amount of the ultraviolet rays to a region where the altered layer is thick is greater than a cumulative irradiation amount of the ultraviolet rays to a region where the altered layer is thin.

[0048] <8> ,according to <1> to <7> The substrate processing method according to any one of the preceding claims, wherein:

[0049] In the step c), the discharge position of the chemical solution on the substrate is scanned.

[0050] In the amorphous silicon layer, a discharge time of the chemical solution from a region where the modified layer is thick is longer than a discharge time of the chemical solution from a region where the modified layer is thin.

[0051] <9> ,according to <1> to <8> The substrate processing method according to any one of the preceding claims, wherein:

[0052] Between the steps b) and c), a step of supplying another chemical solution to the amorphous silicon layer to remove a natural oxide film on the surface of the amorphous silicon layer is further included.

[0053] <10> , a substrate processing device, comprising:

[0054] a substrate holding portion that holds a substrate having an amorphous silicon layer on the surface of which a degenerated layer resulting from dry etching is formed in a horizontal state;

[0055] an ultraviolet irradiation unit for modifying the altered layer by irradiating ultraviolet rays to the altered layer to generate a modified layer; and

[0056] A chemical solution supply unit supplies a chemical solution to the amorphous silicon layer having the modified layer on a surface thereof, so as to wet-etch the amorphous silicon layer.

[0057] <11> ,according to <10> The substrate processing device, wherein:

[0058] In the dry etching, the coating film formed on the surface of the amorphous silicon layer is etched using plasma generated using a fluorocarbon-based gas and an oxygen gas.

[0059] <12> ,according to <11> The substrate processing device, wherein:

[0060] The amorphous silicon layer is an intermediate pattern formed in the middle of multiple patterning of the substrate.

[0061] In the dry etching, the coating film covering the upper surface and side surfaces of the intermediate pattern is anisotropically etched, thereby exposing the upper surface of the intermediate pattern from the coating film and forming side walls of the coating film covering the side surfaces of the intermediate pattern.

[0062] In the wet etching, the intermediate pattern is removed while the sidewall remains.

[0063] <13> ,according to <10> to <12> The substrate processing apparatus according to any one of the preceding claims, wherein:

[0064] The wavelength of the ultraviolet rays is 250 nm or less.

[0065] <14> ,according to <10> to <13> The substrate processing apparatus according to any one of the preceding claims, wherein:

[0066] The cumulative irradiation dose of the ultraviolet light to the amorphous silicon layer is 1000 mJ / cm 2 above.

[0067] <15> ,according to <10> to <14> The substrate processing apparatus according to any one of the preceding claims, wherein:

[0068] The ultraviolet irradiation on the amorphous silicon layer is performed in a low-oxygen atmosphere.

[0069] <16> ,according to <10> to <15> The substrate processing apparatus according to any one of the preceding claims further comprises an irradiation control unit for controlling the ultraviolet irradiation unit.

[0070] The ultraviolet irradiation unit includes:

[0071] an ultraviolet lamp that irradiates the ultraviolet rays toward the substrate; and

[0072] an irradiation area scanning mechanism for scanning the irradiation area of the ultraviolet light on the substrate,

[0073] The irradiation control unit controls at least one of the ultraviolet lamp and the irradiation area scanning mechanism so that the cumulative irradiation amount of the ultraviolet rays in the thick metamorphic layer area of the amorphous silicon layer is greater than the cumulative irradiation amount of the ultraviolet rays in the thin metamorphic layer area.

[0074] <17> ,according to <10> to <16> The substrate processing apparatus according to any one of the preceding claims further comprises a supply control unit for controlling the chemical solution supply unit.

[0075] The liquid medicine supply unit includes:

[0076] a chemical liquid discharge portion that discharges the chemical liquid toward the substrate; and

[0077] a discharge position scanning mechanism for scanning the discharge position of the chemical solution on the substrate,

[0078] The supply control unit controls the discharge position scanning mechanism so that the discharge time of the chemical solution for the thick modified layer region of the amorphous silicon layer is longer than the discharge time of the chemical solution for the thin modified layer region.

[0079] <18> ,according to <10> to <17> The substrate processing device described in any one of the above further includes another chemical liquid supply unit, which supplies another chemical liquid to the amorphous silicon layer between the irradiation of the ultraviolet light to the amorphous silicon layer and the supply of the chemical liquid to remove the natural oxide film on the surface of the amorphous silicon layer.

[0080] The above-mentioned object and other objects, features, aspects and advantages will become more apparent from the following detailed description of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Figure 1 It is a side view of the substrate processing apparatus according to the first embodiment.

[0082] Figure 2 It is a block diagram showing a processing liquid supply unit.

[0083] Figure 3 is a cross-sectional view showing a portion near the upper surface of the substrate.

[0084] Figure 4 is a cross-sectional view showing a portion near the upper surface of the substrate.

[0085] Figure 5 is a cross-sectional view showing a portion near the upper surface of the substrate.

[0086] Figure 6 A diagram showing an example of a substrate processing flow.

[0087] Figure 7 is a graph showing the etching rate of an amorphous silicon layer.

[0088] Figure 8 A diagram showing a portion of a substrate processing flow.

[0089] Figure 9 It is a block diagram showing a processing liquid supply unit.

[0090] Figure 10 It is a side view of the substrate processing apparatus according to the second embodiment. DETAILED DESCRIPTION

[0091] Figure 1 1 is a side view showing the structure of a substrate processing apparatus 1 according to the first embodiment of the present invention. The substrate processing apparatus 1 is a single-sheet type apparatus that processes semiconductor substrates 9 (hereinafter referred to as "substrates 9") one by one. The substrate processing apparatus 1 supplies a processing liquid to the substrate 9 and processes it. Figure 1 , a part of the structure of the substrate processing apparatus 1 is shown in cross section.

[0092] The substrate processing apparatus 1 includes a substrate holding portion 31, a substrate rotating mechanism 33, a cup-shaped portion 4, a processing liquid supply portion 5, a control portion 6, an ultraviolet irradiation portion 7, and a housing 11. The substrate holding portion 31, the substrate rotating mechanism 33, the cup-shaped portion 4, the ultraviolet irradiation portion 7, etc. are accommodated in the internal space of the housing 11. Figure 1 In the embodiment, the housing 11 is shown in cross section (in Figure 10 The same also applies to the case 11. An airflow forming unit 12 is provided on the top cover of the housing 11. The airflow forming unit 12 supplies gas to the internal space and forms an airflow flowing downward (so-called downflow). As the airflow forming unit 12, for example, an FFU (fan filter unit) is used.

[0093] The control unit 6 is arranged outside the housing 11 and controls the substrate holding unit 31, the substrate rotating mechanism 33, the processing liquid supply unit 5 and the ultraviolet irradiation unit 7. The control unit 6 includes, for example, a conventional computer having a processor, a memory, an input / output unit and a bus. The bus is a signal circuit that connects the processor, the memory and the input / output unit. The memory stores programs and various information. The processor uses the memory and the like to perform various processes (for example, numerical calculations) according to the programs stored in the memory. The input / output unit includes a keyboard and a mouse for receiving input from the operator, a display for displaying output from the processor, and a sending unit for sending output from the processor.

[0094] The control unit 6 includes a storage unit 61, an irradiation control unit 62, and a supply control unit 63. The storage unit 61 is primarily implemented by a memory and stores various information such as the processing recipe for the substrate 9. The irradiation control unit 62 is primarily implemented by a processor and controls the ultraviolet irradiation unit 7 and other units according to the processing recipe stored in the storage unit 61. The supply control unit 63 is primarily implemented by a processor and controls the processing liquid supply unit 5 and other units according to the processing recipe stored in the storage unit 61.

[0095] The substrate holder 31 faces the lower main surface (i.e., the lower surface) of the horizontal substrate 9 and holds the substrate 9 from below. The substrate holder 31 is, for example, a mechanical chuck that mechanically supports the substrate 9. The substrate holder 31 is rotatable about a central axis J1 extending in the vertical direction.

[0096] The substrate holding portion 31 includes a holding portion body and a plurality of chuck pins. The holding portion body is a roughly disk-shaped component opposite to the lower surface of the substrate 9. A plurality of chuck pins are arranged at approximately equal angular intervals along the circumferential direction (hereinafter also referred to as "circumferential direction") centered on the central axis J1 at the peripheral portion of the holding portion body. Each chuck pin protrudes upward from the upper surface of the holding portion body and supports the substrate 9 in a manner that contacts the peripheral area and side surfaces of the lower surface of the substrate 9. It should be noted that the substrate holding portion 31 can also be a vacuum suction cup, etc., which adsorbs the central portion of the lower surface of the substrate 9 and holds it.

[0097] The substrate rotating mechanism 33 is disposed below the substrate holding portion 31. The substrate rotating mechanism 33 rotates the substrate 9 together with the substrate holding portion 31 about the central axis J1. The substrate rotating mechanism 33 includes, for example, an electric rotary motor whose rotation axis is connected to the holding portion body of the substrate holding portion 31. The substrate rotating mechanism 33 may also have other structures, such as a hollow motor.

[0098] The processing liquid supply unit 5 supplies multiple processing liquids individually to the substrate 9. These multiple processing liquids include, for example, chemical solutions and rinse solutions (described later). The processing liquid supply unit 5 includes a nozzle 51, an arm 511, and a nozzle rotation mechanism 512. The nozzle 51 supplies the processing liquids from above the substrate 9 to the upper main surface of the substrate 9 (hereinafter referred to as "upper surface 91"). The nozzle 51 is formed of a highly chemical-resistant resin such as Teflon (registered trademark).

[0099] The arm 511 is a rod-shaped member extending in a generally horizontal direction and supports the nozzle 51. The nozzle rotation mechanism 512 is arranged outside the cup-shaped portion 4 in a radial direction (hereinafter referred to as the "radial direction") centered on the central axis J1. The nozzle rotation mechanism 512 includes, for example, an electric rotary motor having a rotation axis extending in the vertical direction. This rotation axis is connected to one end of the arm 511. The nozzle rotation mechanism 512 moves the nozzle 51 in the horizontal direction by rotating the arm 511 about the rotation axis extending in the vertical direction, thereby retracting the nozzle 51 from a retracted position above the substrate 9 to the radially outer side of the cup-shaped portion 4.

[0100] The cup-shaped portion 4 is an annular component centered on the central axis J1. The cup-shaped portion 4 is arranged around the substrate 9 and the substrate holding portion 31 in the entire circumference, covering the sides and bottom of the substrate 9 and the substrate holding portion 31. The cup-shaped portion 4 is a liquid receiving container that receives liquids such as processing liquids that fly from the rotating substrate 9 to the surroundings. The inner surface of the cup-shaped portion 4 is formed of, for example, a waterproof material. Regardless of whether the substrate 9 is rotating or stationary, the cup-shaped portion 4 is stationary in the circumferential direction. A drain port (omitted in the figure) is provided at the bottom of the cup-shaped portion 4 for discharging the processing liquid etc. received by the cup-shaped portion 4 to the outside of the housing 11. The cup-shaped portion 4 can be moved up and down by a lifting mechanism (omitted in the figure). Figure 1 The position around the substrate 9 shown is moved between a processing position and a retreat position located below the processing position.

[0101] The cup 4 can also be Figure 1 The single-layer structure shown is different from the stacked structure of multiple cups stacked in the radial direction. When the cup-shaped portion 4 has a stacked structure, the multiple cups can be independently moved in the vertical direction and switched according to the type of processing liquid scattered from the substrate 9 to receive the processing liquid.

[0102] Figure 2 1 is a block diagram showing the processing liquid supply unit 5 of the substrate processing apparatus 1. Figure 2 , the components other than the treatment liquid supply unit 5 are also shown. The treatment liquid supply unit 5 includes a chemical liquid supply unit 52 and a rinse liquid supply unit 53. The chemical liquid supply unit 52 includes a nozzle 51, an arm 511 (see Figure 1 ), nozzle rotating mechanism 512 (see Figure 1), a chemical supply source 521, and a chemical piping 522. The nozzle 51 is connected to the chemical supply source 521 via the chemical piping 522. The nozzle 51 is a chemical discharge unit that discharges the chemical sent from the chemical supply source 521 toward the upper surface 91 of the substrate 9. The chemical is an etchant used for wet etching of the substrate 9. This etchant is, for example, an alkaline etchant such as an aqueous ammonium hydroxide (NH4OH) solution.

[0103] The rinsing liquid supply unit 53 includes the aforementioned nozzle 51, an arm 511, a nozzle rotating mechanism 512, a rinsing liquid supply source 531, and a rinsing liquid pipe 532. The nozzle 51 is connected to the rinsing liquid supply source 531 via the rinsing liquid pipe 532. The nozzle 51 is a rinsing liquid discharge unit that discharges the rinsing liquid sent from the rinsing liquid supply source 531 toward the upper surface 91 of the substrate 9. For example, an aqueous treatment liquid such as DIW (deionized water), carbonated water, ozone water, or hydrogen water is used as the rinsing liquid.

[0104] As described above, the nozzle 51, arm 511, and nozzle rotation mechanism 512 are shared by the chemical liquid supply unit 52 and the rinse liquid supply unit 53. Separate discharge ports for the chemical liquid and the rinse liquid are provided at the lower end of the nozzle 51, for example. Different types of processing liquids are supplied to the upper surface 91 of the substrate 9 via separate pipes and discharge ports. Alternatively, the chemical liquid discharge nozzle and the rinse liquid discharge nozzle may be provided separately and independently of each other.

[0105] The ultraviolet irradiation unit 7 includes an ultraviolet lamp 71 and a lamp lifting mechanism 72. The ultraviolet lamp 71 is a roughly disk-shaped lamp arranged above the substrate 9. The lamp lifting mechanism 72 is arranged radially outside the cup-shaped portion 4. The lamp lifting mechanism 72 includes, for example, an electric linear motor or a ball screw and an electric rotary motor. The lamp lifting mechanism 72 is connected to the ultraviolet lamp 71 to move the ultraviolet lamp 71 in the vertical direction. The ultraviolet lamp 71 can be moved in the vertical direction. Figure 1 The ultraviolet lamp 71 moves between a retracted position (shown by a solid line) and an irradiation position (shown by a two-dot chain line) located below the retracted position. As the ultraviolet lamp 71 moves from the retracted position to the irradiation position, the nozzle 51 is retracted from above the substrate 9 to the retracted position by the nozzle rotation mechanism 512. From this irradiation position, the ultraviolet lamp 71 irradiates the entire upper surface 91 of the substrate 9 with ultraviolet rays.

[0106] An excimer lamp or a low-pressure mercury lamp can be used as the ultraviolet lamp 71. The wavelength of the ultraviolet light emitted from the ultraviolet lamp 71 is preferably 250 nm or less, more preferably 172 nm or less. The lower limit of the wavelength of the ultraviolet light is not particularly limited, and is, for example, 120 nm or more.

[0107] Figure 3 This is a cross-sectional view showing an enlarged portion of the upper surface 91 of the substrate 9. Figure 3 In the illustrated substrate 9, an insulating film 94 is formed on the upper surface of a silicon substrate main body 93, a titanium nitride (TiN) film 95 is formed on the upper surface of the insulating film 94, and a silicon nitride film 96 is formed on the upper surface of the titanium nitride film 95. The insulating film 94, the titanium nitride film 95, and the silicon nitride film 96 are respectively provided on the upper surface of the silicon substrate main body 93 with substantially uniform thickness. Figure 3 On the entire upper surface of the silicon substrate body 93.

[0108] An amorphous silicon layer 97 is formed on the upper surface of the silicon nitride film 96. The amorphous silicon layer 97 is a fine pattern that is a collection of a plurality of pattern elements 971. The amorphous silicon layer 97 is an intermediate pattern formed in the middle of the multi-patterning of the substrate 9. Figure 3 Four pattern elements 971 are shown. Figure 3 The width of the pattern elements 971 in the horizontal direction is, for example, 30 nm to 100 nm. The height of the pattern elements 971 in the vertical direction is, for example, 20 nm to 100 nm. The upper surface of the silicon nitride film 96 is exposed between adjacent pattern elements 971.

[0109] The side surfaces of each pattern element 971 of the amorphous silicon layer 97 are covered by sidewalls 981. The sidewalls 981 are thin films formed of silicon oxide, silicon nitride, silicon oxynitride, or the like. Figure 3 The width of sidewall 981 in the horizontal direction is smaller than the width of pattern element 971, for example, 10 nm to 20 nm. The vertical height of sidewall 981 is approximately the same as the height of pattern element 971, and the upper and lower ends of sidewall 981 are located at approximately the same vertical positions as the upper and lower ends of pattern element 971. The upper surface of pattern element 971 is not covered by the thin film formed of the aforementioned silicon oxide, silicon nitride, or silicon oxynitride, and is exposed from the two sidewalls 981 covering the side surfaces of pattern element 971.

[0110] Figure 3 The substrate 9 shown is formed in another apparatus different from the substrate processing apparatus 1. Specifically, first, an insulating film 94, a titanium nitride film 95, a silicon nitride film 96, and an amorphous silicon layer 97 (i.e., an intermediate pattern) are sequentially formed on a silicon substrate main body 93. Figure 4As shown, a coating film 98 is formed to cover the topmost amorphous silicon layer 97. Coating film 98 is, for example, a silicon oxide film, a silicon nitride film, or a silicon oxynitride film. Coating film 98 entirely covers the top and side surfaces of each pattern element 971 of amorphous silicon layer 97, as well as the top surface of silicon nitride film 96 exposed between pattern elements 971. Coating film 98 is formed, for example, by CVD (Chemical Vapor Deposition), PVD (Physical Vapor Deposition), or ALD (Atomic Layer Deposition).

[0111] Next, for Figure 4 The coating film 98 shown is dry-etched. This dry etching is, for example, plasma etching performed by using a plasma generated by a fluorocarbon gas (CxFy) and an oxygen gas. This dry etching is essentially anisotropic etching that etches only in the up and down directions. By performing this anisotropic etching on the coating film 98, the upper surface of each pattern element 971 of the amorphous silicon layer 97 is exposed from the coating film 98, and the upper surface of the silicon nitride film 96 between the adjacent pattern elements 971 is also exposed from the coating film 98. In addition, the side surfaces of each pattern element 971 of the amorphous silicon layer 97 are maintained in a state of being covered by the coating film 98. Thus, Figure 3 The sidewalls 981 covering the side surfaces of the pattern elements 971 are formed on the above-mentioned coating film 98 (see Figure 4 ) The remaining parts during dry etching.

[0112] In the substrate 9, during the dry etching, oxygen (O), carbon (C), fluorine (F), etc. are incident on the upper surface of each pattern element 971 exposed from the coating film 98 (that is, the surface of the amorphous silicon layer 97 opposite to the silicon substrate main body 93), and as shown in FIG. Figure 5 As shown in FIG. 1 , a modified layer 972 is formed on the upper surface of each pattern element 971. Figure 5 In the figure, the altered layer 972 is marked with parallel oblique lines that are different from those in the pattern element 971 other than the altered layer 972. It is believed that in this altered layer 972, which originates from the dry etching in the previous step, oxygen and carbon that entered the amorphous silicon layer 97 bond with the silicon of the amorphous silicon layer 97 to form "Si-O bonds" and "Si-C bonds." Furthermore, these Si-O bonds and Si-C bonds are believed to be the main factors that hinder the wet etching of the amorphous silicon layer 97 in the substrate processing apparatus 1 (described later). It should be noted that there is a possibility that only one of the Si-O bonds and the Si-C bonds is formed in the altered layer 972.

[0113] Next, refer to Figure 6The processing of the substrate 9 in the substrate processing apparatus 1 is described. In the substrate processing apparatus 1, first, there is Figure 3 The substrate 9 with the amorphous silicon layer 97 and the sidewall 981 is moved into Figure 1 The substrate processing apparatus 1 shown in FIG. 1 is held in a horizontal state by the substrate holding portion 31 (step S11). Figure 5 As shown, a degraded layer 972 resulting from dry etching is formed on the surface of the amorphous silicon layer 97 .

[0114] Next, the ultraviolet irradiation unit 7 is controlled by the irradiation control unit 62 so that the ultraviolet lamp 71 is arranged at Figure 1 Ultraviolet light is emitted from the ultraviolet lamp 71 toward the entire upper surface 91 of the substrate 9, at the irradiation position indicated by the two-dot chain line. Thus, ultraviolet light is irradiated onto the altered layer 972 of the amorphous silicon layer 97. Ultraviolet light from the ultraviolet lamp 71 is irradiated onto the altered layer 972 for a predetermined time. As a result, the Si-O bonds and Si-C bonds in the altered layer 972 are severed. As a result, the altered layer 972 is modified to form a modified layer (step S12).

[0115] As described above, in step S12, the wavelength of the ultraviolet light irradiated onto the amorphous silicon layer 97 is preferably 250 nm or less. The energy of ultraviolet light with a wavelength of 250 nm or less is 478 kJ / mol or greater, which is greater than the Si-O bond energy of 443 kJ / mol and the Si-C bond energy of 337 kJ / mol. Therefore, by irradiating the altered layer 972 with ultraviolet light having a wavelength of 250 nm or less, the Si-O and Si-C bonds in the altered layer 972 can be appropriately severed.

[0116] In step S12, it is preferable that the cumulative irradiation amount of ultraviolet rays irradiated from the ultraviolet lamp 71 to the altered layer 972 of the amorphous silicon layer 97 is 1000 mJ / cm 2 The upper limit of the cumulative irradiation dose is not particularly limited, but is, for example, 3000 mJ / cm 2 The cumulative irradiation amount is calculated by dividing the illuminance of ultraviolet rays on the upper surface of the amorphous silicon layer 97 (mW / cm 2 ) is calculated by multiplying the ultraviolet irradiation time (sec (seconds)).

[0117] Preferably, the ultraviolet irradiation to the amorphous silicon layer 97 in step S12 is carried out in a low-oxygen atmosphere. More preferably, the ultraviolet irradiation is carried out in an atmosphere with an oxygen concentration of less than 1% by volume. The low-oxygen atmosphere can be achieved by a variety of methods. For example, the low-oxygen atmosphere can also be achieved by supplying an inert gas such as nitrogen (N2) gas from the air flow forming portion 12 to the internal space of the housing 11 and making the internal space of the housing 11 an inert gas atmosphere. The supply of inert gas to the housing 11 can also be carried out using a gas supply mechanism other than the air flow forming portion 12. In addition, the ultraviolet irradiation can also be carried out in a low-oxygen atmosphere by supplying an inert gas only to the space between the ultraviolet lamp 71 and the substrate 9 from the side of the space.

[0118] When the ultraviolet irradiation of the amorphous silicon layer 97 is completed, the ultraviolet lamp 71 is moved from the above-mentioned irradiation position to the retreat position by the lamp lifting mechanism 72. In addition, the nozzle 51 is moved from the retreat position to above the substrate 9 by the nozzle rotating mechanism 512. Then, by rotating the substrate 9 by the substrate rotating mechanism 33 and controlling the chemical supply unit 52 by the supply control unit 63, a chemical solution is supplied from the nozzle 51 to the rotating substrate 9. Specifically, a columnar chemical solution is discharged from the nozzle 51 toward the center of the upper surface 91 of the substrate 9. The chemical solution supplied to the substrate 9 spreads radially outward from the center of the substrate 9 under the action of centrifugal force and is applied to the entire upper surface 91 of the substrate 9.

[0119] The chemical solution is an etchant such as an aqueous ammonium hydroxide solution, and the chemical solution is supplied to the amorphous silicon layer 97 having the modified layer on its surface, thereby wet etching the amorphous silicon layer 97 (step S13). On the substrate 9, each pattern element 971 of the amorphous silicon layer 97 is selectively etched away, while the sidewalls 981 covering the side surfaces of the pattern elements 971 are not etched and remain on the silicon nitride film 96.

[0120] In the substrate processing apparatus 1, during the wet etching of the amorphous silicon layer 97, the nozzle rotating mechanism 512 may be driven by the supply control unit 63 to reciprocate the nozzle 51 substantially in the radial direction above the substrate 9. This can improve the uniformity of the etching liquid applied to the entire surface of the substrate 9.

[0121] Figure 7 This graph shows the etching rate of the amorphous silicon layer 97 during the wet etching process. This etching rate is obtained when a 65°C aqueous ammonium hydroxide solution prepared by mixing ammonium hydroxide and DIW at a ratio of 1:15 is used as the etching solution. Example 1 in the graph shows the etching rate of the amorphous silicon layer 97 having the modified layer formed on its surface. In Example 1, the cumulative dose of ultraviolet light applied to the modified layer 972 in step S12 is 1000 mJ / cm 2Comparative Example 1 shows the etching rate of the amorphous silicon layer 97 having the altered layer 972 formed on the surface (i.e., the amorphous silicon layer before ultraviolet irradiation). Comparative Example 2 shows the etching rate of the amorphous silicon layer 97 without the altered layer 972 and the modified layer formed on the surface (i.e., the amorphous silicon layer not subjected to plasma etching).

[0122] like Figure 7 As shown, the etching rate in Comparative Example 1 is significantly lower, approximately 3% of the etching rate in Comparative Example 2, due to the wet etching being hindered by the altered layer 972. Therefore, in the state of Comparative Example 1, wet etching of the amorphous silicon layer 97 does not substantially proceed. On the other hand, the etching rate in Example 1 recovers to approximately 43% of the etching rate in Comparative Example 2 due to the modification of the altered layer 972 by ultraviolet irradiation. Therefore, wet etching of the amorphous silicon layer 97 can be performed appropriately. It should be noted that the etching rate in Example 1 is more than 10 times that of Comparative Example 1.

[0123] In the substrate processing apparatus 1 , the supply of the chemical solution (ie, etching solution) from the nozzle 51 is continued for a predetermined time, so that all the pattern elements 971 of the amorphous silicon layer 97 are removed from between the sidewalls 981 , and the wet etching of the substrate 9 is completed.

[0124] At the end of the wet etching process, the supply control unit 63 controls the rinsing liquid supply unit 53 to supply rinsing liquid from the nozzle 51 to the upper surface 91 of the rotating substrate 9, thereby rinsing the substrate 9 (step S14). The supply of rinsing liquid is then stopped, and the substrate 9 is dried (step S15). During the drying process, the rotation speed of the substrate 9 increases, and the residual processing liquid on the substrate 9 is scattered radially outward from the edge of the substrate 9 by centrifugal force, thereby being removed from the substrate 9. In steps S13 to S15, the processing liquids such as the chemical solution and rinsing liquid scattered radially outward from the substrate 9 are received by the cup 4 and discharged to the outside of the housing 11. After the drying process, the substrate 9 is removed from the substrate processing apparatus 1 and transported to another apparatus for subsequent processing. In this other apparatus, for example, dry etching of the silicon nitride film 96 is performed using the sidewall 981 as a mask. In the substrate processing apparatus 1, steps S11 to S15 are sequentially performed on multiple substrates 9.

[0125] As described above, the above-mentioned substrate processing method includes the following steps: a step of maintaining the substrate 9 having an amorphous silicon layer 97 having a metamorphic layer 972 formed on the surface thereof due to dry etching in a horizontal state (step S11); a step of modifying the metamorphic layer 972 by irradiating ultraviolet rays to the metamorphic layer 972 to generate a modified layer (step S12); and a step of supplying a chemical solution to the amorphous silicon layer 97 having the modified layer on the surface thereof and performing wet etching on the amorphous silicon layer 97 (step S13).

[0126] This increases the etching rate of the amorphous silicon layer 97 that has been reduced by the altered layer 972. As a result, the amorphous silicon layer 97 can be wet-etched efficiently.

[0127] In the dry etching described above, it is preferable to etch the coating film 98 formed on the surface of the amorphous silicon layer 97 using plasma generated using a fluorocarbon-based gas and an oxygen gas. In the substrate processing method described above, the Si—O bonds and Si—C bonds in the altered layer 972 can be cut by irradiating the amorphous silicon layer 97 with ultraviolet light, thereby increasing the etching rate of the amorphous silicon layer 97, which has been reduced due to the Si—O bonds and Si—C bonds.

[0128] As described above, amorphous silicon layer 97 is preferably an intermediate pattern formed during the multi-patterning of substrate 9. Furthermore, during the dry etching process, anisotropic etching is performed on coating film 98 covering the upper surface and side surfaces of the intermediate pattern, thereby exposing the upper surface of the intermediate pattern from coating film 98, thereby forming sidewalls 981 of coating film 98 covering the side surfaces of the intermediate pattern. Furthermore, during the wet etching process, the intermediate pattern is removed, leaving sidewalls 981. In this substrate processing method, the etching rate of amorphous silicon layer 97 can be increased by irradiating the altered layer 972 with ultraviolet light, thereby enabling efficient multi-patterning of substrate 9.

[0129] As described above, the wavelength of the ultraviolet light irradiated onto the altered layer 972 in step S12 is preferably 250 nm or less. Ultraviolet light with a wavelength of 250 nm or less has energy greater than the bond energy of the Si—O bond and the bond energy of the Si—C bond. Therefore, the altered layer 972 can be modified (i.e., the Si—O bonds and Si—C bonds in the altered layer 972 can be cut) appropriately by ultraviolet light irradiation.

[0130] As mentioned above, the cumulative irradiation dose of ultraviolet rays in step S12 is preferably 1000 mJ / cm 2 As described above, the altered layer 972 can be appropriately modified by ultraviolet irradiation.

[0131] As described above, the ultraviolet irradiation in step S12 is preferably performed in a low-oxygen atmosphere. This prevents or suppresses the absorption of ultraviolet light by oxygen during irradiation of the amorphous silicon layer 97. As a result, the altered layer 972 can be efficiently modified by ultraviolet irradiation.

[0132] The substrate processing apparatus 1 includes a substrate holder 31, an ultraviolet irradiation unit 7, and a chemical supply unit 52. The substrate holder 31 holds a substrate 9 having an amorphous silicon layer 97 with a degraded layer 972 formed on its surface due to dry etching in a horizontal position. The ultraviolet irradiation unit 7 modifies the degraded layer 972 by irradiating ultraviolet light onto the degraded layer 972, thereby generating a modified layer. The chemical supply unit 52 supplies a chemical solution to the amorphous silicon layer 97 having the modified layer on its surface, thereby wet-etching the amorphous silicon layer 97. As described above, this increases the etching rate of the amorphous silicon layer 97, which has been reduced by the degraded layer 972. Consequently, the amorphous silicon layer 97 can be efficiently wet-etched.

[0133] In the processing of the substrate 9 by the substrate processing apparatus 1, as Figure 8 As shown, a pretreatment (step S121) of the amorphous silicon layer 97 may be performed between the irradiation of the amorphous silicon layer 97 with ultraviolet rays in step S12 and the supply of a chemical solution (i.e., an etching solution) to the amorphous silicon layer 97 in step S13. In step S121, a chemical solution (e.g., hydrofluoric acid (HF)) different from the chemical solution in step S13 is supplied to the amorphous silicon layer 97, thereby removing the surface natural oxide film on the surface of the amorphous silicon layer 97 (i.e., the upper surface of the altered layer 972).

[0134] In this case, if Figure 9 As shown, the processing liquid supply unit 5 of the substrate processing apparatus 1 is provided with, in addition to the liquid supply unit 52 and the rinse liquid supply unit 53, another liquid supply unit 54 for supplying the other liquid to the substrate 9. The other liquid supply unit 54 includes a nozzle 51, an arm 511 (see Figure 1 ), nozzle rotating mechanism 512 (see Figure 1 ), other chemical liquid supply source 541 and other chemical liquid piping 542. The nozzle 51 is connected to the other chemical liquid supply source 541 via the other chemical liquid piping 542. The nozzle 51 also serves as an other chemical liquid discharge unit for discharging the other chemical liquid (for example, dilute hydrofluoric acid at room temperature with a concentration of 0.3%) sent from the other chemical liquid supply source 541 toward the upper surface 91 of the substrate 9. It should be noted that the nozzle for discharging this other chemical liquid can also be provided independently of the nozzle for discharging the etching liquid.

[0135] As described above, the substrate processing method preferably further includes a step (step S121) of supplying another chemical solution to the amorphous silicon layer 97 between steps S12 and S13 to remove the natural oxide film on the surface of the amorphous silicon layer 97. By removing the natural oxide film on the surface of the amorphous silicon layer 97 before wet etching, a decrease in the etching rate caused by the natural oxide film on the surface can be prevented or suppressed. As a result, the wet etching of the amorphous silicon layer 97 can be performed more efficiently.

[0136] Next, a substrate processing apparatus 1 a according to a second embodiment of the present invention will be described. Figure 10 1 is a side view showing the structure of the substrate processing apparatus 1a. Figure 3 The substrate 9 shown is subjected to Figure 1 The substrate processing apparatus 1 shown in the figure performs substantially the same process, wet etching the amorphous silicon layer 97 .

[0137] The substrate processing apparatus 1a includes an irradiation unit 14, a liquid processing unit 15, a control unit 6, and a housing 11. The irradiation unit 14 and the liquid processing unit 15 are arranged inside a single housing 11. The control unit 6 has a Figure 1 The control unit 6 has the same structure as shown. As described above, the control unit 6 includes the storage unit 61, the irradiation control unit 62, and the supply control unit 63.

[0138] The irradiation unit 14 includes a first substrate holding portion 31a and an ultraviolet irradiation portion 7a. Figure 1 The substrate holding portion 31 shown in FIG. 1 is substantially the same structure as that shown in FIG. 1 , and holds the substrate 9 in a horizontal state from the bottom. Figure 10 In the illustrated example, the substrate rotating mechanism 33 is not provided in the irradiation unit 14, and the first substrate holding portion 31a does not rotate.

[0139] The ultraviolet irradiation section 7a includes an ultraviolet lamp 71a and an irradiation area scanning mechanism 73. The ultraviolet lamp 71a is a roughly rod-shaped lamp extending in a roughly straight line in a direction perpendicular to the paper surface in the figure. The ultraviolet rays emitted from the ultraviolet lamp 71a are irradiated to a strip-shaped or linear irradiation area extending in a roughly straight line in a direction perpendicular to the paper surface on the substrate 9. The irradiation area is a part of the upper surface 91 of the substrate 9, and crosses the upper surface 91 of the substrate 9 in a direction perpendicular to the paper surface. The ultraviolet lamp 71a uses an excimer lamp or a low-pressure mercury lamp, etc., similar to the ultraviolet lamp 71 mentioned above. The wavelength of the ultraviolet rays emitted from the ultraviolet lamp 71a is preferably less than 250nm, and more preferably less than 172nm. The lower limit of the wavelength of the ultraviolet rays is not particularly limited, and for example, it is greater than 120nm.

[0140] The irradiation area scanning mechanism 73 moves the ultraviolet lamp 71a in the horizontal direction in the figure above the substrate 9, thereby scanning the irradiation area on the substrate 9 in the horizontal direction in the figure. The irradiation area scanning mechanism 73 includes, for example, an electric linear motor, a ball screw, and an electric rotary motor. In the substrate processing apparatus 1a, the irradiation control unit 62 of the control unit 6 controls the irradiation area scanning mechanism 73 to control the movement speed of the ultraviolet lamp 71a and the scanning speed of the ultraviolet irradiation area on the substrate 9. It should be noted that the output of the ultraviolet lamp 71a is maintained substantially constant during the movement of the ultraviolet lamp 71a.

[0141] The liquid processing unit 15 has the same structure as the substrate holding unit 31 except that the ultraviolet irradiation unit 7 is omitted and a second substrate holding unit 31b is provided with the same structure as the substrate holding unit 31. Figure 1 The structure of the substrate processing apparatus 1 shown in FIG. 1 is substantially the same as that of the substrate processing apparatus 1 shown in FIG. In the following description, components of the liquid processing unit 15 corresponding to those of the substrate processing apparatus 1 are denoted by the same reference numerals. In the substrate processing apparatus 1a, the substrate holding portion 31 for holding the substrate 9 in a horizontal state is formed by the first substrate holding portion 31a and the second substrate holding portion 31b.

[0142] In the liquid processing unit 15, when a chemical liquid (i.e., an etching solution) is discharged from the nozzle 51 toward the upper surface 91 of the substrate 9, the nozzle 51 is reciprocated in a substantially radial direction above the substrate 9 by the nozzle rotation mechanism 512. This scans the discharge position of the chemical liquid on the upper surface 91 of the substrate 9. In other words, the nozzle rotation mechanism 512 functions as a discharge position scanning mechanism that scans the discharge position of the chemical liquid on the upper surface 91 of the substrate 9. In the substrate processing apparatus 1a, the nozzle rotation mechanism 512 is controlled by the supply control unit 63 of the control unit 6 to control the movement speed of the nozzle 51 and, therefore, the scanning speed of the discharge position of the chemical liquid on the substrate 9.

[0143] The processing flow of the substrate 9 in the substrate processing apparatus 1a is similar to Figure 6 In the processing of the substrate 9 in the substrate processing apparatus 1a, first, the substrate 9 having Figure 3 The substrate 9 with the amorphous silicon layer 97 and the sidewall 981 shown is carried into the substrate processing apparatus 1a and held in a horizontal state by the first substrate holding portion 31a of the irradiation unit 14 (step S11). As described above, a degraded layer 972 (see FIG. 1 ) resulting from dry etching is formed on the surface of the amorphous silicon layer 97. Figure 5 ).

[0144] Next, the ultraviolet irradiation unit 7a of the irradiation unit 14 is controlled by the irradiation control unit 62 to irradiate the modified layer 972 of the amorphous silicon layer 97 with ultraviolet rays. Specifically, ultraviolet rays are emitted from the ultraviolet lamp 71a and irradiated onto an irradiation area extending substantially linearly on the upper surface 91 of the substrate 9. Furthermore, the ultraviolet lamp 71a is scanned from the left to the right in the figure above the substrate 9 using the irradiation area scanning mechanism 73, thereby irradiating the entire upper surface 91 of the substrate 9 with ultraviolet rays. As a result, the Si-O bonds and Si-C bonds in the modified layer 972 are severed, and the modified layer 972 is modified, thereby generating the aforementioned modified layer (step S12).

[0145] In step S12, as described above, it is preferable that the wavelength of the ultraviolet rays irradiated to the amorphous silicon layer 97 is 250 nm or less. Thus, the modified layer 972 can be modified appropriately by ultraviolet irradiation (i.e., the Si-O bonds and Si-C bonds in the modified layer 972 are cut). In step S12, as described above, it is preferable that the cumulative irradiation dose of ultraviolet rays irradiated from the ultraviolet lamp 71a to the modified layer 972 of the amorphous silicon layer 97 is 1000 mJ / cm 2 As described above, the altered layer 972 can be appropriately modified by ultraviolet irradiation.

[0146] The ultraviolet irradiation of the amorphous silicon layer 97 in step S12 is preferably performed in a low-oxygen atmosphere. This prevents or suppresses absorption of the ultraviolet light by oxygen during irradiation of the amorphous silicon layer 97, as described above. Consequently, the altered layer 972 can be efficiently modified by ultraviolet irradiation. It should be noted that in step S12, the ultraviolet lamp 71a may be moved back and forth in the left-right direction above the substrate 9, thereby performing multiple ultraviolet scans on the substrate 9.

[0147] After step S12 is completed, the substrate 9 is transported from the irradiation unit 14 to the liquid treatment unit 15 using a transport mechanism such as a robot (not shown), and is held in a horizontal state by the second substrate holding portion 31b of the liquid treatment unit 15. Next, the substrate 9 is rotated by the substrate rotating mechanism 33, and the supply control unit 63 controls the chemical solution supply unit 52 (see FIG. 1 ). Figure 2 ) is controlled to supply a chemical solution (i.e., an etching solution) from the nozzle 51 to the rotating substrate 9. As described above, the nozzle 51 is reciprocated in a substantially radial direction above the substrate 9 by the nozzle rotation mechanism 512, scanning the discharge position of the chemical solution on the upper surface 91 of the substrate 9. Furthermore, by supplying the chemical solution to the amorphous silicon layer 97 having the modified layer on its surface, the amorphous silicon layer 97 is wet-etched (step S13).

[0148] After the wet etching is completed, a rinsing liquid is supplied from the nozzle 51 to the upper surface 91 of the rotating substrate 9 to perform a rinsing process on the substrate 9 (step S14). Thereafter, the supply of the rinsing liquid is stopped and the substrate 9 is dried (step S15). In the substrate processing device 1a, the above-mentioned steps S11 to S15 are sequentially performed on a plurality of substrates 9. It should be noted that, in the substrate processing device 1a, the above-mentioned step S121 (see Figure 8 ).

[0149] In the substrate processing apparatus 1a, Figure 1The substrate processing apparatus 1 shown can similarly increase the etching rate of the amorphous silicon layer 97, which has been reduced by the altered layer 972. Specifically, the etching rate of the amorphous silicon layer 97 can be increased by severing the Si-O bonds and Si-C bonds in the altered layer 972. This allows efficient wet etching of the amorphous silicon layer 97. As a result, the aforementioned multiple patterning can be efficiently performed on the substrate 9.

[0150] As described above, in the substrate processing apparatus 1a, the ultraviolet irradiation area on the substrate 9 is scanned in step S12. At this time, the irradiation control unit 62 preferably controls the irradiation area scanning mechanism 73 so that the scanning speed of the ultraviolet irradiation area for the thicker regions of the modified layer 972 in the amorphous silicon layer 97 is slower than the scanning speed of the ultraviolet irradiation area for the thinner regions of the modified layer 972. As a result, the cumulative amount of ultraviolet irradiation for the thicker regions of the modified layer 972 in the amorphous silicon layer 97 is greater than the cumulative amount of ultraviolet irradiation for the thinner regions of the modified layer 972. As a result, the modification uniformity of the modified layer 972 across the entire amorphous silicon layer 97 can be improved. It should be noted that this improvement in modification uniformity can be confirmed by an improvement in the uniformity of the etching rate across the entire amorphous silicon layer 97.

[0151] In the substrate processing apparatus 1a, the output of the ultraviolet lamp 71a can be controlled using the irradiation control unit 62 so that the ultraviolet irradiance in thick areas of the altered layer 972 is greater than that in thin areas of the altered layer 972. In this case, the scanning speed of the ultraviolet irradiation area can be maintained constant, and the cumulative irradiation amount of ultraviolet light in thick areas of the altered layer 972 within the amorphous silicon layer 97 can be made greater than that in thin areas of the altered layer 972. As a result, the uniformity of modification of the altered layer 972 across the entire amorphous silicon layer 97 can be improved, as described above.

[0152] As described above, in the substrate processing apparatus 1a, the discharge position of the chemical solution on the substrate 9 is scanned in step S13. At this time, the nozzle rotation mechanism 512 (i.e., the discharge position scanning mechanism) is preferably controlled by the supply control unit 63 so that the scanning speed of the discharge position of the chemical solution for the thicker region of the altered layer 972 in the amorphous silicon layer 97 is slower than the scanning speed of the discharge position of the chemical solution for the thinner region of the altered layer 972. As a result, the discharge time of the chemical solution for the thicker region of the altered layer 972 in the amorphous silicon layer 97 is longer than the discharge time of the chemical solution for the thinner region of the altered layer 972. As a result, the uniformity of the wet etching (e.g., the uniformity of the wet etching rate) can be improved across the entire amorphous silicon layer 97.

[0153] Various modifications can be made to the above-described substrate processing method and substrate processing apparatus 1 , 1 a .

[0154] For example, the ultraviolet irradiation of the amorphous silicon layer 97 in step S12 does not necessarily have to be performed in a low-oxygen atmosphere, and may be performed in, for example, an air atmosphere.

[0155] In step S12, the cumulative dose of ultraviolet rays directed to the amorphous silicon layer 97 may be appropriately changed according to the type and thickness of the altered layer 972. For example, the cumulative dose of ultraviolet rays directed to the amorphous silicon layer 97 may be lower than 1000 mJ / cm 2 .

[0156] In step S12, the wavelength of the ultraviolet rays irradiated to the amorphous silicon layer 97 may be appropriately changed according to the type and thickness of the altered layer 972. For example, the wavelength of the ultraviolet rays irradiated to the amorphous silicon layer 97 may be longer than 250 nm.

[0157] The amorphous silicon layer 97 of the substrate 9 processed in the substrate processing apparatuses 1 and 1 a does not necessarily have to be an intermediate pattern formed during the multi-patterning of the substrate 9 , but may be an amorphous silicon layer obtained by performing a process other than multi-patterning.

[0158] The altered layer 972 modified in the substrate processing apparatuses 1 and 1 a is not limited to a layer formed by plasma etching using plasma generated using a fluorocarbon gas and an oxygen gas, but may be a layer formed by altering the surface of the amorphous silicon layer 97 by other treatments.

[0159] In the substrate processing apparatus 1, the ultraviolet irradiation to the amorphous silicon layer 97 can also be performed by Figure 10 In addition, in the substrate processing apparatus 1a, ultraviolet irradiation for the amorphous silicon layer 97 can also be performed using Figure 1 The ultraviolet irradiation unit 7 is shown. In the substrate processing apparatus 1a, the irradiation unit 14 and the liquid processing unit 15 may be housed in different housings.

[0160] The substrate processing apparatus 1 described above can be used not only for semiconductor substrates but also for processing glass substrates used in flat panel displays (FPDs) such as liquid crystal displays and organic EL (electroluminescence) displays, or for other display devices. Furthermore, the substrate processing apparatus 1 described above can also be used for processing optical disc substrates, magnetic disc substrates, magneto-optical disc substrates, photomask substrates, ceramic substrates, and solar cell substrates.

[0161] The configurations in the above-described embodiment and various modifications can be appropriately combined as long as they do not contradict each other.

[0162] The invention has been described in detail above, but the above description is for illustrative purposes only and not limiting. Therefore, many modifications and aspects are possible without departing from the scope of the invention.

[0163] Description of Reference Numerals

[0164] 1.1a Substrate processing device

[0165] 7.7a Ultraviolet irradiation part

[0166] 9 substrate

[0167] 31 substrate holding portion

[0168] 31a first substrate holding portion

[0169] 31b second substrate holding portion

[0170] 51 nozzles

[0171] 52 liquid medicine supply unit

[0172] 54 Other liquid supply department

[0173] 62 Irradiation Control Unit

[0174] 63 Supply Control Unit

[0175] 71, 71a ultraviolet lamp

[0176] 73 irradiation area scanning mechanism

[0177] 97 amorphous silicon layer

[0178] 98 coating

[0179] 512 nozzle rotation mechanism

[0180] 972 metamorphic layer

[0181] 981 sidewall

[0182] Steps S11 to S15

Claims

1. A substrate processing method comprising the following steps: a) holding a substrate having an amorphous silicon layer on the surface of which a degenerate layer due to dry etching is formed in a horizontal state; b) a step of modifying the deteriorated layer by irradiating the deteriorated layer with ultraviolet rays to form a modified layer; and c) supplying a chemical solution to the amorphous silicon layer having the modified layer on its surface to wet-etch the amorphous silicon layer, The ultraviolet ray irradiation in the step b) is performed in a low-oxygen atmosphere.

2. The substrate processing method according to claim 1, wherein: In the step b), the ultraviolet irradiation area on the substrate is scanned. In the amorphous silicon layer, a cumulative irradiation amount of the ultraviolet rays to a region where the altered layer is thick is greater than a cumulative irradiation amount of the ultraviolet rays to a region where the altered layer is thin.

3. The substrate processing method according to claim 1 or 2, wherein: In the step c), the discharge position of the chemical solution on the substrate is scanned. In the amorphous silicon layer, a discharge time of the chemical solution from a region where the modified layer is thick is longer than a discharge time of the chemical solution from a region where the modified layer is thin.

4. The substrate processing method according to claim 1 or 2, wherein: Between the steps b) and c), a step of supplying another chemical solution to the amorphous silicon layer to remove a natural oxide film on the surface of the amorphous silicon layer is further included.

5. A substrate processing apparatus comprising: a substrate holding portion that holds a substrate having an amorphous silicon layer on the surface of which a degenerated layer resulting from dry etching is formed in a horizontal state; an ultraviolet irradiation unit for irradiating the altered layer with ultraviolet rays to thereby modify the altered layer and generate a modified layer; and a chemical solution supplying unit for supplying a chemical solution to the amorphous silicon layer having the modified layer on its surface to wet-etch the amorphous silicon layer; The processing device further includes an irradiation control unit for controlling the ultraviolet irradiation unit. The ultraviolet irradiation unit includes: an ultraviolet lamp that irradiates the ultraviolet rays toward the substrate; and an irradiation area scanning mechanism for scanning the irradiation area of the ultraviolet light on the substrate, The irradiation control unit controls at least one of the ultraviolet lamp and the irradiation area scanning mechanism so that the cumulative irradiation amount of the ultraviolet rays in the thick metamorphic layer area of the amorphous silicon layer is greater than the cumulative irradiation amount of the ultraviolet rays in the thin metamorphic layer area.

6. The substrate processing device according to claim 5 further comprises another chemical liquid supply unit, which supplies another chemical liquid to the amorphous silicon layer between the irradiation of the ultraviolet light to the amorphous silicon layer and the supply of the chemical liquid to remove the natural oxide film on the surface of the amorphous silicon layer.

7. A substrate processing apparatus comprising: a substrate holding portion that holds a substrate having an amorphous silicon layer on the surface of which a degenerated layer resulting from dry etching is formed in a horizontal state; an ultraviolet irradiation unit for irradiating the altered layer with ultraviolet rays to thereby modify the altered layer and generate a modified layer; and a chemical solution supplying unit for supplying a chemical solution to the amorphous silicon layer having the modified layer on its surface to wet-etch the amorphous silicon layer; The substrate processing apparatus further includes a supply control unit for controlling the chemical solution supply unit. The liquid medicine supply unit includes: a chemical liquid discharge portion that discharges the chemical liquid toward the substrate; and a discharge position scanning mechanism for scanning the discharge position of the chemical solution on the substrate, The supply control unit controls the discharge position scanning mechanism so that the discharge time of the chemical solution for the thick modified layer region of the amorphous silicon layer is longer than the discharge time of the chemical solution for the thin modified layer region.

8. The substrate processing device according to claim 7 further comprises another chemical liquid supply unit, which supplies another chemical liquid to the amorphous silicon layer between the irradiation of the ultraviolet light to the amorphous silicon layer and the supply of the chemical liquid to remove the natural oxide film on the surface of the amorphous silicon layer.

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