Etching apparatus and etching method

Abstract

The present invention provides an etching apparatus and an etching method capable of improving the etching amount uniformity of an in-plane silicon oxide film of a substrate. The etching apparatus of the present invention etches a silicon oxide film using a processing gas containing hydrogen fluoride and ammonia, and has a chamber, a gas supply section, a water vapor supply section, and a control section. The chamber is configured to be able to accommodate a substrate having a surface provided with the silicon oxide film. The gas supply section is configured to be able to supply the processing gas or a precursor gas of the processing gas to the chamber. The water vapor supply section is configured to be able to supply water vapor to the chamber. During etching processing, the control section controls the gas supply section and the water vapor supply section in a manner to supply the processing gas or the precursor gas and the water vapor to the chamber.

Description

Technical Field

[0001] This invention relates to an etching apparatus and an etching method for etching silicon oxide films. Background Technology

[0002] Apparatus and methods for etching silicon oxide films formed on the surface of silicon substrates are known. For example, Patent Document 1 discloses an oxide film removal apparatus comprising a vacuum chamber, a first gas supply section for supplying a mixture of ammonia and nitrogen, and a second gas supply section for supplying nitrogen trifluoride gas. In this oxide film removal apparatus, an etchant containing fluorine and hydrogen (e.g., NF-2-fluoride) is used. x H y Remove the silicon oxide film.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-17661.

[0006] The problem the invention aims to solve

[0007] However, as described in Patent Document 1, when etching silicon oxide films using etchants containing fluorine and hydrogen, the distribution of the amount of etching within the substrate surface is sometimes uneven. Summary of the Invention

[0008] In view of the above, the object of the present invention is to provide an etching apparatus and etching method that can improve the uniformity of etching amount of silicon oxide film in the substrate surface.

[0009] Solution for solving the problem

[0010] To achieve the above objectives, one aspect of the present invention relates to an etching apparatus that uses a process gas comprising hydrogen fluoride and ammonia to etch a silicon oxide film.

[0011] The etching apparatus has a chamber, a gas supply section, a steam supply section, and a control section.

[0012] The chamber is configured to accommodate a substrate with the silicon oxide film on its surface.

[0013] The gas supply unit is configured to supply the processing gas or the precursor gas of the processing gas to the chamber.

[0014] The steam supply unit is configured to supply steam to the chamber.

[0015] During the etching process, the control unit controls the gas supply unit and the water vapor supply unit to supply the processing gas or the precursor gas and the water vapor to the chamber.

[0016] The control unit can control the water vapor supply unit to supply water vapor to the chamber at a partial pressure of 0.1 Pa or higher and 100 Pa or lower.

[0017] The gas supply unit may have a first gas supply line and a second gas supply line.

[0018] The first gas supply line is capable of supplying a first precursor gas to the chamber, the first precursor gas having at least one of a hydrogen-containing gas or a hydrogen radical.

[0019] The second gas supply line is capable of supplying a second precursor gas to the chamber, the second precursor gas having at least one of a fluorine-containing gas or a fluorine radical.

[0020] The hydrogen fluoride can be generated by reacting the first precursor gas with the second precursor gas in the chamber.

[0021] In this case, the first gas supply line may also have a free radical generation section, which generates hydrogen free radicals from hydrogen-containing gas.

[0022] The chamber may have:

[0023] A processing chamber capable of housing the substrate;

[0024] A gas supply chamber, which is connected to the gas supply unit; and

[0025] A spray plate, disposed between the gas supply chamber and the treatment chamber, includes multiple through holes.

[0026] In this case, the steam supply unit can be connected to the gas supply chamber.

[0027] Other aspects of the invention relate to an etching method that uses a process gas containing hydrogen fluoride and ammonia to etch a silicon oxide film.

[0028] The processing gas or the precursor gas of the processing gas is supplied to a chamber containing a substrate having the silicon oxide film on its surface.

[0029] Water vapor is supplied to the chamber.

[0030] In the chamber supplied with the water vapor, the silicon oxide film is etched using the processing gas.

[0031] Water vapor can also be supplied to the chamber at a partial pressure of 0.1 Pa or higher and 100 Pa or lower.

[0032] Invention Effects

[0033] According to the present invention, the etching uniformity of the silicon oxide film within the substrate surface can be improved. Attached Figure Description

[0034] Figure 1 This is a schematic cross-sectional view illustrating the etching apparatus according to the first embodiment of the present invention.

[0035] Figure 2 A flowchart illustrating the etching method using the aforementioned etching apparatus.

[0036] Figure 3 This is a graph showing the distribution of etching amount within the substrate surface during the etching process described in the embodiments of the above-described implementation.

[0037] Figure 4 This is a graph showing the distribution of etching amount within the substrate surface during the etching process described in the comparative example of the above embodiments.

[0038] Figure 5 This is a schematic cross-sectional view illustrating the etching apparatus according to the second embodiment of the present invention.

[0039] Figure 6 This is a schematic cross-sectional view illustrating the etching apparatus according to the third embodiment of the present invention.

[0040] Figure 7 This is a schematic cross-sectional view illustrating the etching apparatus according to the fourth embodiment of the present invention.

[0041] Figure 8 This is a schematic cross-sectional view illustrating the etching apparatus according to the fifth embodiment of the present invention.

[0042] Figure 9 This is a schematic cross-sectional view illustrating the etching apparatus according to the sixth embodiment of the present invention. Detailed Implementation

[0043] [Content of this invention]

[0044] This invention relates to an etching apparatus and etching method for etching silicon oxide films using a process gas containing hydrogen fluoride (HF) and ammonia (NH3).

[0045] The aforementioned processing gas is supplied to a chamber containing a substrate with a silicon oxide film on its surface. In the processing gas, HF reacts with NH3, resulting in the following reaction.

[0046] HF + NH3 → NH4F…(1)

[0047] Ammonium fluoride (NH4F) is thus generated. The generated NH4F reacts with the silicon oxide film on the surface of the substrate. This reaction is represented by the following formula (2).

[0048] SiO2+6NH4F→(NH4)2SiF6+2H2O+4NH3…(2)

[0049] In this way, by reacting NH4F with SiO2 in the silicon oxide film, a reaction product ((NH4)2SiF6) consisting of an ammonia complex that readily decomposes at 100–200 °C is generated on the substrate surface. The silicon oxide film is then etched.

[0050] In the reaction of formula (2), H2O and NH3 are generated together with the above reaction products. Since the H2O is generated on the surface of the substrate, the amount of H2O may become less at the periphery of the substrate than at the center.

[0051] According to the inventors' understanding, the reaction in equation (2) can be considered to be mainly due to the ionization of fluorine (F) from NH4F. - The fluorine etching occurs due to collisions with SiO2, with H2O participating in the ionization of the fluorine. Therefore, it can be considered that the uneven distribution of H2O on the substrate surface leads to uneven etching within the substrate surface.

[0052] Therefore, the present invention is characterized in that, in the above-described etching process, water vapor (H2O gas) is supplied to the chamber in addition to the aforementioned processing gas. As will be described in detail later, uneven distribution of H2O on the substrate surface is suppressed, and the uniformity of the etching amount within the substrate surface is improved.

[0053] Furthermore, on the surface of the substrate, a portion of the supplied or generated H2O can be liquid. Therefore, when referring to gaseous H2O, it is labeled as "water vapor," and when referring to both gaseous and liquid H2O, it is labeled as "H2O."

[0054] The following is a reference to the appendix. Figure 1 The embodiments of the present invention will be described below. The X-axis, Y-axis, and Z-axis shown in the figures represent mutually orthogonal directions.

[0055] <First Implementation Method>

[0056] [Structure of the etching apparatus]

[0057] Figure 1 This is a schematic cross-sectional view illustrating the etching apparatus 100 according to the first embodiment of the present invention.

[0058] like Figure 1 As shown, the etching apparatus 100 includes a chamber 10, a gas supply unit 20, a steam supply unit 30, and a control unit 40. The etching apparatus 100 is a dry etching apparatus that uses a process gas containing HF and NH3 to etch a silicon oxide film, such as a remote plasma etching apparatus capable of generating free radicals outside the chamber 10.

[0059] The chamber 10 is configured to accommodate a substrate W with a silicon oxide film on its surface. In this embodiment, the chamber 10 has a chamber body 11 and a substrate support 12.

[0060] The chamber body 11 is configured, for example, as a metal vacuum chamber. The chamber body 11 includes a bottom 111, a top plate 112, and side walls 113. The chamber body 11 can be configured such that the top plate 112 is separable, or the bottom 111, top plate 112, and side walls 113 can be integrated. Furthermore, the chamber body 11 is configured to have an exhaust port 114 connected to a vacuum pump and capable of venting exhaust from this exhaust port 114. The exhaust port 114 is, for example, located at the bottom 111.

[0061] The top plate 112 is configured to face the bottom plate 111 in the Z-axis direction. In this embodiment, a gas pressure head 13, described later, is mounted on the top plate 112. The top plate 112 may, for example, have an opening in the Z-axis direction that connects to the first gas supply line 21, described later.

[0062] The substrate support 12 is configured, for example, as a stage capable of arranging the substrate W. The substrate support 12 includes a support surface 121 for arranging the substrate W. The support surface 121 is arranged, for example, facing the top plate 112 in the Z-axis direction.

[0063] In this embodiment, the interior of chamber 10 is divided by a gas pressure head 13 having a spray plate 131. That is, chamber 10 further includes: a processing chamber 14 capable of housing the substrate W; a gas supply chamber 15 connected to the gas supply unit 20 described later; and a spray plate 131 disposed between the processing chamber 14 and the gas supply chamber 15. In this embodiment, the gas supply chamber 15 and the support surface 121 are arranged facing each other in the Z-axis direction.

[0064] In this embodiment, the spray plate 131 is configured as part of the gas pressure head 13. The gas pressure head 13 includes the spray plate 131 and the pressure head body 132.

[0065] The spray plate 131 has a plurality of through holes 133. The through holes 133 function as gas outlet holes for spraying gas from the gas supply chamber 15 to the processing chamber 14. The spray plate 131 is arranged, for example, with the plurality of through holes 133 facing the support surface 121 in the Z-axis direction.

[0066] The pressure head body 132 is disposed between the spray plate 131 and the top plate 112. A gas supply chamber 15 is formed within the internal space of the gas pressure head 13 formed between the pressure head body 132 and the spray plate 131. The pressure head body 132 includes, for example: an opening 134 connected to the first gas supply line 21 (described later) and opening in the Z-axis direction; a plate-facing surface 135 facing the spray plate 131; and an annular conical surface 136 disposed around the opening 134, connecting the plate-facing surface 135 to the opening 134.

[0067] The gas supply unit 20 is configured to supply the aforementioned processing gas or a precursor gas of the processing gas to the chamber 10.

[0068] As mentioned above, the processing gas is a reactive gas containing HF and NH3.

[0069] The precursor gas is a gas that contains the precursors of the processing gas.

[0070] The gas supply unit 20 can supply HF gas and NH3 gas to the chamber 10. Alternatively, the gas supply unit 20 can supply precursor gas to the chamber 10. In the latter case, the process gas is generated, for example, by reacting the precursor gas supplied via the gas supply unit 20 within the chamber 10.

[0071] In addition, the processing gas and precursor gas can be not only ordinary gases, but can also contain atoms in a free radical state.

[0072] In this embodiment, the gas supply unit 20 has a first gas supply line 21 and a second gas supply line 22.

[0073] The first gas supply line 21 is configured to supply chamber 10 with a first precursor gas containing at least one of a hydrogen-containing gas or hydrogen free radicals. "Hydrogen-containing gas" means a gas containing hydrogen (H2) or hydrides that are not in a free radical state; "hydrogen free radical" means hydrogen (H2) in a free radical state. * The first precursor gas, for example, contains H2. * And NH3 gas.

[0074] The first gas supply line 21 includes, for example, a free radical generation unit 211 that generates hydrogen free radicals from a hydrogen-containing gas; a first supply port 212 that opens into the chamber 10; and a first conduit 213 that connects the free radical generation unit 211 and the first supply port 212.

[0075] The radical generation unit 211 is configured as a remote plasma source. Specifically, the radical generation unit 211 can be a microwave plasma source, a high-frequency plasma source, a capacitively coupled plasma source, an inductively coupled plasma source, etc. In this embodiment, the radical generation unit 211 is configured as a microwave plasma source, for example, including a discharge tube and a microwave source. A hydrogen-containing gas (not shown) is introduced into the discharge tube. The discharge tube is connected to the first conduit 213. The microwave source, for example, irradiates the discharge tube with excited microwaves. The "hydrogen-containing gas" introduced into the radical generation unit 211 is, for example, a mixture of NH3 gas and nitrogen (N2) as a carrier gas.

[0076] In this embodiment, the first supply port 212 opens in the gas supply chamber 15. The first supply port 212 opens, for example, at a position opposite to the spray plate 131 in the Z-axis direction, and is connected to the opening 134 of the pressure head body 132.

[0077] The second gas supply line 22 is configured to supply chamber 10 with a second precursor gas containing at least one of a fluorine-containing gas or fluorine radicals. "Fluorine-containing gas" means a gas containing fluorine gas (F2) that is not in a free radical state or a fluoride; "fluorine radical" means fluorine gas in a free radical state (F2). * The second precursor gas is, for example, nitrogen trifluoride (NF3) gas.

[0078] The second gas supply line 22 includes, for example, a second supply port 221 at the opening of the chamber 10 and a second pipe 222 connected to the second supply port 221.

[0079] In this embodiment, the second supply port 221 opens in the gas supply chamber 15. The second supply port 221 opens, for example, in the conical surface 136 of the pressure head body 132. The second gas supply line 22 may include a plurality of second supply ports 221, which may also be arranged on the conical surface 136 in a manner surrounding the first supply port 212.

[0080] In this embodiment, the first gas supply line 21 and the second gas supply line 22 are connected to the gas supply chamber 15. Thereby, the first precursor gas and the second precursor gas react within the gas supply chamber 15 to generate the processing gas used for the etching process, and the processing gas diffuses within the gas supply chamber 15. Therefore, the processing gas is uniformly supplied to the substrate W via the spray plate 131.

[0081] The water vapor supply unit 30 is configured to supply water vapor to the chamber 10. The water vapor functions as an etching promoting gas. By supplying water vapor to the chamber 10 through the water vapor supply unit 30, water vapor is supplied to the entire surface of the substrate W, and the uneven distribution of H2O within the surface of the substrate W is suppressed. Therefore, the uniformity of the etching amount within the surface of the substrate W is improved.

[0082] The steam supply unit 30 includes, for example, a third supply port 31 at the opening of the chamber 10 and a third pipe 32 connected to the third supply port 31.

[0083] In this embodiment, the third supply port 31 opens into the gas supply chamber 15. Figure 1 In the example shown, the third supply port 31 opens, for example, on the conical surface 136 of the pressure head body 132. The steam supply section 30 may include multiple third supply ports 31, which may also be arranged on the conical surface 136 in a manner surrounding the first supply port 212. Figure 1 In the example shown, the third supply port 31 is located downstream of the second supply port 221.

[0084] In the third pipe 32, for example, a vaporizer is connected to generate water vapor from liquid water.

[0085] In this embodiment, the water vapor supply unit 30 is connected to the gas supply chamber 15, and water vapor diffuses within the gas supply chamber 15. Thus, water vapor is uniformly supplied to the substrate W via the spray plate 131. Therefore, uneven distribution of H2O within the surface of the substrate W is further effectively suppressed, and the uniformity of the etching amount within the surface of the substrate W is further improved.

[0086] During the etching process, the control unit 40 controls the gas supply unit 20 and the water vapor supply unit 30 to supply processing gas or precursor gas and water vapor to the chamber 10.

[0087] The control unit 40 is implemented using computer hardware components such as CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory) and necessary software. The control unit 40 can at least control the gas supply unit 20 and the steam supply unit 30, or it can be configured to control the etching apparatus 100 as a whole.

[0088] [Etching Method]

[0089] Figure 2 This is a flowchart illustrating the etching method of this embodiment.

[0090] The etching method using the etching apparatus 100 with the above-described structure will now be described.

[0091] First, such as Figure 1As shown, a substrate W with a silicon oxide film on its surface is disposed in the chamber 10. The substrate W is, for example, a silicon substrate. The silicon oxide film can be a natural oxide film or a film formed by oxidation treatment or the like. The chamber 10 is depressurized to a specified pressure.

[0092] Then, as Figure 2 As shown, the gas supply unit 20 supplies a processing gas containing HF and NH3 or a precursor gas of the processing gas to the chamber 10 on which the substrate W is disposed (step S1). That is, the control unit 40 controls the gas supply unit 20 in such a way as to supply the processing gas or the precursor gas.

[0093] In step S1, for example, the control unit 40 controls the first gas supply line 21 to supply the chamber 10 with a first precursor gas containing at least one of a hydrogen-containing gas or a hydrogen free radical.

[0094] In the first gas supply line 21, for example as a raw material gas, a mixture of NH3 gas and N2 gas is introduced into the free radical generation unit 211. In the free radical generation unit 211, a portion of the NH3 gas and N2 gas become free radicals to generate H2. * and N * As a result, the first precursor gas, for example, contains NH3 gas, H2O, etc. * N2 gas and N * .

[0095] Furthermore, for example, the control unit 40 controls the second gas supply line 22 to supply a second precursor gas containing fluorine or fluorine radicals to the chamber 10. The second precursor gas is, for example, NF3 gas.

[0096] In this embodiment, the first precursor gas and the second precursor gas are mixed in the gas supply chamber 15 of the chamber 10, and the following reaction (3) occurs.

[0097] H * +NF3→HF+NF2…(3)

[0098] Thus, a processing gas is generated in the gas supply chamber 15, the processing gas containing HF and NH3 that has not become a free radical in the first gas supply line 21. The HF generated in the above reaction is in a highly reactive state.

[0099] On the other hand, such as Figure 2 As shown, the steam supply unit 30 supplies steam to the chamber (step S2). That is, the control unit 40 controls the steam supply unit 30 to supply steam. In this embodiment, steam is supplied to the gas supply chamber 15 and then to the processing chamber 14 via the spray plate 131. Preferred conditions in step S2 will be described later.

[0100] Next, as Figure 2 As shown, in the chamber 10 supplied with water vapor, a process gas containing HF and NH3 is used to etch the silicon oxide film (step S3). In this step, during the etching process, the control unit 40 controls the gas supply unit 20 and the water vapor supply unit 30 to supply the process gas or precursor gas and water vapor to the chamber 10.

[0101] In the gas supply chamber 15, ammonium fluoride (NH4F) is generated by reacting HF and NH3 contained in the treatment gas according to the above formula (1). Formula (1) is shown again.

[0102] HF + NH3 → NH4F…(1)

[0103] The generated NH4F is supplied to the treatment chamber 14, for example, via spray plate 131.

[0104] NH4F supplied to processing chamber 14 reacts with the silicon oxide film on the surface of substrate W. The reaction of NH4F with SiO2 in the silicon oxide film results in the reaction described in equation (2) above, generating a reaction product ((NH4)2SiF6) composed of an ammonia complex on the surface of substrate W. Equation (2) is shown again.

[0105] SiO2+6NH4F→(NH4)2SiF6+2H2O+4NH3…(2)

[0106] In this embodiment, "etching silicon oxide film" means generating the above-mentioned reaction products. These reaction products are then removed by thermal decomposition of the substrate W at a specified temperature (e.g., 100–200°C). The removal of the reaction products can be performed either within the same chamber 10 or in different chambers.

[0107] In step S3, from the viewpoint of efficiently generating reaction products, the substrate W can also be maintained at a temperature above -5°C and below 50°C.

[0108] The H2O generated by equation (2) is produced on the surface of substrate W along with the reaction products, and therefore does not form on the outer side of substrate W. In other words, the amount of H2O from this reaction is less at the periphery of substrate W than at the center. As described above, it can be considered that H2O participates in the etching of the silicon oxide film by NH4F. If the H2O distribution on the surface of substrate W is uneven, uneven formation of the reaction products may occur, resulting in uneven etching within the surface of substrate W.

[0109] Therefore, in this embodiment, the etching process described above is performed in the chamber 10, where water vapor is supplied via the water vapor supply unit 30. As a result, during the etching process, the water vapor diffuses within the chamber 10 and is uniformly supplied to the entire surface of the substrate W. Consequently, the reaction of the above formula (2) is uniformly promoted within the surface of the substrate W. As a result, uneven formation of reaction products within the surface of the substrate W is suppressed, and the uniformity of the etching amount is improved.

[0110] In step S2, the control unit 40 controls the water vapor supply unit 30 to supply water vapor to the chamber 10 at a partial pressure of 0.1 Pa or more and 100 Pa or less. As a result, sufficient water vapor is supplied to the chamber 10 to diffuse throughout the entire surface of the substrate W, more effectively addressing the uneven distribution of H2O within the surface of the substrate W. Therefore, the uniformity of the etching amount within the surface of the substrate W is further improved.

[0111] In addition, during the etching process in step S3, the pressure inside the chamber 10 can be, for example, 10 Pa or more and 1000 Pa or less, and further, 10 Pa or more and 500 Pa or less.

[0112] In step S2, the control unit 40 can also control the water vapor supply unit 30 to start supplying water vapor at the same time as the gas supply unit 20 supplies gas. As a result, water vapor diffuses into the entire surface of the substrate W at the same time as the etching process begins, thus more reliably suppressing the unevenness of the etching amount in the surface of the substrate W.

[0113] [Example]

[0114] The effects of this embodiment will now be specifically explained using examples and comparative examples.

[0115] As an example, using a Figure 1 The etching apparatus shown is for a steam supply section, which etches a silicon substrate with silicon oxide on its surface. The silicon substrate is assumed to be a circular substrate with a radius of approximately 150 mm.

[0116] A mixture of NH3 and N2 gases is introduced into the first gas supply pipeline as the raw material gas. The microwave frequency in the free radical generation section is set to 2.45 GHz, and the discharge power is set to 1800 kW.

[0117] Introduce NF3 into the second gas supply line.

[0118] Steam is introduced into the steam supply unit.

[0119] The pressure inside the etching chamber was adjusted to approximately 500 Pa. The partial pressure of NH3 gas was adjusted to approximately 56 Pa, the partial pressure of N2 gas to approximately 430 Pa, the partial pressure of NF3 gas to approximately 12 Pa, and the partial pressure of water vapor to approximately 2 Pa.

[0120] The substrate temperature during the etching process is set to approximately 20°C.

[0121] As a comparative example, an etching apparatus without a water vapor supply section was used to etch a silicon substrate with silicon oxide on its surface without supplying water vapor into the chamber.

[0122] The same gas as in the embodiment is introduced into the first gas supply line and the second gas supply line. The discharge conditions of the free radical generation section and the substrate temperature in the etching process are also set to be the same.

[0123] The pressure inside the etching chamber was adjusted to approximately 500 Pa. The partial pressure of NH3 gas was adjusted to approximately 56 Pa, the partial pressure of N2 gas to approximately 432 Pa, and the partial pressure of NF3 gas to approximately 12 Pa.

[0124] Figure 3 and Figure 4 The graphs showing the distribution of etching amount within the substrate surface during the etching processes of the embodiments and comparative examples are shown, with the horizontal axis representing the position (mm) within the substrate and the vertical axis representing the etching amount (nm). Figure 3 This indicates the result of the embodiment. Figure 4 This indicates the result of the comparison example.

[0125] like Figure 4 As shown, in the etching process of the comparative example without water vapor supply, the amount of etching at the periphery of the substrate varies greatly.

[0126] In contrast, such as Figure 3 As shown, in the etching process of the embodiment where water vapor was supplied, the change in the amount of etching at the periphery of the substrate was suppressed compared with the results of the comparative example.

[0127] These results show that when using processing gases containing HF and NH3 to etch silicon oxide films, supplying water vapor into the chamber improves the uniformity of etching within the substrate surface.

[0128] <Second Implementation>

[0129] Figure 5 This is a schematic cross-sectional view illustrating the etching apparatus 100A according to the second embodiment of the present invention.

[0130] As shown in the figure, the etching apparatus 100A has the same chamber 10, gas supply unit 20 and control unit 40 as the first embodiment, but has a water vapor supply unit 30A that is different from the first embodiment.

[0131] In the following embodiments, the same markings are used for structures that are the same as those in the first embodiment described above, and the descriptions are omitted. The main difference is described.

[0132] The steam supply unit 30A includes, for example, a third supply port 31A at the opening of the chamber 10 and a third pipe 32A connected to the third supply port 31A.

[0133] The third supply port 31A opens, for example, on the plate-facing surface 135 of the pressure head body 132. Figure 5 In the example shown, the steam supply section 30A includes a plurality of third supply ports 31A that open on the plate facing surface 135, or it may include a single third supply port 31A.

[0134] As a result, water vapor diffuses within the gas supply chamber 15 and is uniformly supplied to the entire surface of the substrate W via the spray plate 131. This significantly improves the uniformity of the etching amount within the surface of the substrate W.

[0135] <Third Implementation Method>

[0136] Figure 6 This is a schematic cross-sectional view illustrating the etching apparatus 100B according to the third embodiment of the present invention.

[0137] As shown in the figure, the etching apparatus 100B has the same chamber 10, gas supply unit 20 and control unit 40 as the first embodiment, but has a water vapor supply unit 30B that is different from the first embodiment.

[0138] like Figure 6 As shown, the steam supply unit 30B includes a third supply port 31B opening into the first pipe 213 and a third pipe 32B connected to the third supply port 31B. In this embodiment, steam is supplied to the chamber 10 via the third pipe 32B and a portion of the first pipe 213 of the first gas supply line 21.

[0139] As a result, water vapor is supplied from upstream of the gas supply chamber 15, allowing it to diffuse more evenly within the gas supply chamber 15. Consequently, water vapor is supplied more evenly to the entire surface of the substrate W via the spray plate 131, further improving the uniformity of the etching amount within the surface of the substrate W.

[0140] <Fourth Implementation>

[0141] Figure 7 This is a schematic cross-sectional view illustrating the etching apparatus 100C according to the fourth embodiment of the present invention.

[0142] As shown in the figure, the etching apparatus 100C has the same chamber 10, gas supply unit 20 and control unit 40 as the first embodiment, but has a water vapor supply unit 30C that is different from the first embodiment.

[0143] like Figure 7As shown, the steam supply unit 30C includes a third supply port 31C opening into the second pipe 222 and a third pipe 32C connected to the third supply port 31C. That is, in this embodiment, steam is supplied to the chamber 10 via the third pipe 32C and a portion of the second pipe 222 of the second gas supply line 22. Figure 7 In the example shown, the steam supply unit 30C includes a single third supply port 31C, but it may also include multiple third supply ports 31C connected to multiple second pipes 222.

[0144] As a result, water vapor is supplied from upstream of the gas supply chamber 15, allowing it to diffuse more evenly within the gas supply chamber 15. Consequently, water vapor is supplied more evenly to the entire surface of the substrate W via the spray plate 131, further improving the uniformity of the etching amount within the surface of the substrate W.

[0145] <Fifth Implementation>

[0146] Figure 8 This is a schematic cross-sectional view illustrating the etching apparatus 100D according to the fifth embodiment of the present invention.

[0147] As shown in the figure, the etching apparatus 100D has the same chamber 10, gas supply unit 20 and control unit 40 as the first embodiment, but has a water vapor supply unit 30D that is different from the first embodiment.

[0148] like Figure 8 As shown, the steam supply unit 30D includes, for example, a third supply port 31D at the opening of the processing chamber 14 of the chamber 10 and a third pipe 32D connected to the third supply port 31D.

[0149] like Figure 8 As shown, the third supply port 31D opens, for example, in the side wall 113 of the chamber 10. Figure 8 In the example shown, the steam supply unit 30D includes a single third supply port 31D, but it may also include multiple third supply ports 31D.

[0150] Thus, water vapor is supplied to the processing chamber 14 of the chamber 10 and can diffuse within the processing chamber 14. Therefore, the water vapor can diffuse throughout the entire surface of the substrate W, improving the uniformity of the etching amount within the surface of the substrate W.

[0151] <Sixth Implementation Method>

[0152] Figure 9 This is a schematic cross-sectional view illustrating the etching apparatus 100E according to the sixth embodiment of the present invention.

[0153] As shown in the figure, the etching apparatus 100E has the same chamber 10, gas supply unit 20 and control unit 40 as the first embodiment, but has a water vapor supply unit 30E that is different from the first embodiment.

[0154] like Figure 9 As shown, the steam supply unit 30E includes, for example, a third supply port 31E at the opening of the processing chamber 14 of the chamber 10 and a third pipe 32E connected to the third supply port 31E.

[0155] like Figure 9 As shown, the third supply port 31E opens into the support surface 121 of the substrate support portion 12. Figure 9 In this configuration, the steam supply section 30E includes a plurality of third supply ports 31E. The plurality of third supply ports D are arranged, for example, along the periphery of the support surface 121.

[0156] Therefore, water vapor can be supplied more directly to the periphery of the substrate W, where the amount of H2O generated along with the reaction product ((NH4)2SiF6) is small. This results in a more reliable improvement in the uniformity of etching within the substrate W.

[0157] <Other Implementation Methods>

[0158] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0159] The chamber 10 is not limited to the structure described above.

[0160] For example, the gas supply chamber 15 may not be configured to face the support surface 121 in the Z-axis direction, but rather to be configured along the side of the support surface 121, i.e., the side wall 113 of the chamber 10. In this case, the spray plate 131 may also be configured with a plurality of through holes 133 extending along the X-axis or Y-axis direction.

[0161] Alternatively, chamber 10 may not have a gas pressure head 13, and may be divided into a treatment chamber 14 and a gas supply chamber 15 by spray plates 131.

[0162] Furthermore, the chamber 10 may not be divided into a processing chamber 14 and a gas supply chamber 15; instead, the entire interior of the chamber 10 may be configured as the processing chamber 14. In this case, the gas supply unit 20 may be directly connected to the top plate, side wall, etc., of the processing chamber 14.

[0163] Furthermore, the first gas supply line 21 and the second gas supply line 22 of the gas supply section 20 are not limited to the structure described above, and can be connected to positions different from the example shown in the figure.

[0164] Alternatively, the gas supply unit 20 is not limited to a structure that supplies the precursor gas of the processing gas to the chamber 10. For example, a processing gas containing HF and NH3 may be generated outside the chamber 10 and supplied to the chamber 10.

[0165] Explanation of reference numerals in the attached figures

[0166] 100, 100A, 100B, 100C, 100D, 100E: Etching apparatus

[0167] 10: Chamber

[0168] 20: Gas Supply Department

[0169] 21: First gas supply pipeline

[0170] 22: Second gas supply pipeline

[0171] 30, 30A, 30B, 30C, 30D, 30E: Steam Supply Department

[0172] 40: Control Department

Claims

1. An etching apparatus for etching a silicon oxide film using a process gas comprising hydrogen fluoride and ammonia, and water vapor, comprising: A chamber capable of housing a substrate having the silicon oxide film on its surface; A gas supply unit capable of supplying the processing gas or the precursor gas of the processing gas to the chamber; A water vapor supply unit that supplies water vapor in a manner that allows it to diffuse throughout the entire surface of the substrate within the chamber; as well as The control unit controls the gas supply unit and the water vapor supply unit during the etching process to supply the processing gas or the precursor gas and the water vapor to the chamber. The gas supply unit has a first gas supply pipeline and a second gas supply pipeline. The first gas supply line includes a free radical generation section that generates hydrogen free radicals from a hydrogen-containing gas. The first gas supply line is capable of supplying a first precursor gas containing hydrogen free radicals to the chamber. The second gas supply line can supply the chamber with a second fluorine-containing precursor gas. The hydrogen fluoride is generated by reacting the first precursor gas and the second precursor gas in the chamber. The first gas supply line and the second gas supply line are respectively connected to the chamber. The first gas supply line has a first supply port at the opening of the chamber, the second gas supply line has a plurality of second supply ports at the opening of the chamber, and the steam supply section has a plurality of third supply ports at the opening of the chamber. The plurality of second supply ports and the plurality of third supply ports are respectively arranged to surround the first supply port.

2. The etching apparatus according to claim 1, wherein, The control unit controls the steam supply unit to supply steam to the chamber at a partial pressure of 0.1 Pa or more and 100 Pa or less.

3. The etching apparatus according to claim 1 or 2, wherein, The chamber has: A processing chamber capable of housing the substrate; A gas supply chamber, which is connected to the gas supply unit; and A spray plate, disposed between the gas supply chamber and the treatment chamber, includes multiple through holes.

4. The etching apparatus according to claim 3, wherein, The steam supply unit is connected to the gas supply chamber.

5. An etching method for etching a silicon oxide film using a process gas containing hydrogen fluoride and ammonia, and water vapor, wherein, The processing gas or a precursor gas for the processing gas is supplied to a chamber containing a substrate having the silicon oxide film on its surface. Water vapor is supplied in a manner that allows it to diffuse throughout the entire surface of the substrate within the chamber. In the chamber supplied with the water vapor, the silicon oxide film is etched using the processing gas. A first precursor gas containing hydrogen radicals is supplied to the chamber from a first supply port at the opening of the chamber via a first gas supply line connected to the chamber. A second fluorine-containing precursor gas is supplied to the chamber through a plurality of second supply ports at the chamber opening of a second gas supply line that is respectively connected to the chamber by the first gas supply line. The water vapor is supplied from a plurality of third supply ports at the opening of the chamber. The second precursor gas and the water vapor are supplied in a manner that surrounds the first supply port. The hydrogen fluoride is generated by reacting the first precursor gas with the second precursor gas in the chamber.

6. The etching method according to claim 5, wherein, Water vapor is supplied to the chamber at a partial pressure of 0.1 Pa or higher and 100 Pa or lower.

Images