JP2005191144A - Method and apparatus for substrate treatment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate treatment method and apparatus which can make treatments easily and can form a thin oxide film evenly on a clean substrate surface. <P>SOLUTION: In wash-treatment sections 5a-5d, high-density ozone water is supplied onto the surface of a substrate W being held and rotated by a spin chuck 21 from a nozzle 50 for oxidation treatment. Then, hydrogen fluoride water is supplied onto the surface of the substrate W which has been supplied with the high-density ozone water from a nozzle 70 for etching. It is preferred that the high-density ozone water and the hydrogen fluoride water are supplied to the substrate W several times, say, twice or three times, etc. Thereafter, low-density ozone water is supplied onto the surface of the substrate W from the nozzle 50 for oxidation treatment. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus for performing various processes on a substrate.

  2. Description of the Related Art Conventionally, a substrate processing apparatus has been used to perform various processes on a substrate such as a semiconductor wafer, a glass substrate for a photomask, a glass substrate for a liquid crystal display device, and a glass substrate for an optical disk. For example, in a semiconductor device manufacturing process, a substrate processing apparatus is used in which a series of processes are unitized and a plurality of processing units are integrated in order to increase production efficiency.

  In recent years, a high dielectric constant gate insulating film (hereinafter abbreviated as a Hi-k film) may be formed on a substrate in a substrate processing process by a substrate processing apparatus. This Hi-k film is used to suppress gate leakage current in the transistor.

  In general, the Hi-k film is formed on the substrate surface by, for example, chemical vapor deposition (CVD). At the time of forming such a Hi-k film, a thin Hi-k film at the atomic layer level can be obtained by using an atomic layer deposition (ALD) technique.

  When forming such a thin Hi-k film, an oxide film needs to be formed in advance on the substrate surface.

If an oxide film is not formed on the substrate surface, even if an attempt is made to start the formation of the Hi-k film, the film formation does not proceed until a predetermined time elapses, making it difficult to control the thickness of the Hi-k film. Become. On the other hand, when an oxide film is formed on the substrate surface in advance, the film formation proceeds immediately, so that the thickness of the Hi-k film can be easily controlled.
JP 2000-100777 A

  By the way, it is preferable that the oxide film formed on the substrate surface in advance when forming the Hi-k film is as thin as possible. This is because, when a thick oxide film is formed as a base of a high dielectric constant Hi-k film, that is, when the equivalent oxide thickness (EOT) is excessively large, the substrate from the Hi-k film is removed. This is because current leakage cannot be sufficiently suppressed.

  Here, it is generally known to use low concentration ozone water of 1 ppm or less in order to obtain a uniform ultrathin oxide film at low cost.

  In the case of forming an oxide film on the substrate surface, for example, after etching the substrate surface using an aqueous solution containing hydrogen fluoride, ozone water is supplied to the substrate to form an oxide film (see, for example, Patent Document 1). ). However, when such an oxide film is formed, if the substrate surface is contaminated with an organic substance or the like, the growth rate of the oxide film varies, and an extremely thin oxide film cannot be obtained with good reproducibility.

  Therefore, in order to completely remove such contaminants such as organic substances, in addition to the etching step, a cleaning process for removing contamination on the substrate surface and a cleaning liquid used for the cleaning step are required. As a result, complicated substrate processing and complicated structure of the substrate processing apparatus have been problems.

  An object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of simple processing and capable of forming a thin and uniform oxide film on a clean substrate surface.

  A substrate processing method according to a first aspect of the present invention is a substrate processing method for performing a predetermined process on a substrate, the step of supplying ozone water having a first ozone concentration to the substrate, and the first ozone concentration. A step of supplying hydrogen fluoride water to the substrate after the supply of ozone water; and a step of supplying ozone water having a second ozone concentration lower than the first ozone concentration to the substrate after the supply of hydrogen fluoride water. It is equipped with.

  In the substrate processing method according to the first invention, by supplying ozone water having the first ozone concentration to the substrate, an oxide film is formed on the substrate surface, and impurities such as organic substances existing on the substrate surface are formed. Is oxidized.

  Etching is performed by supplying hydrogen fluoride water to the substrate. Thereby, impurities such as organic substances oxidized by ozone water having the first ozone concentration are removed together with the oxide film by lift-off.

  As described above, by supplying ozone water having the first ozone concentration and hydrogen fluoride water to the substrate, impurities such as organic substances existing on the substrate surface in advance are removed without requiring a cleaning process or the like. A clean substrate surface can be obtained by simple processing.

  Then, ozone water having a second ozone concentration lower than the first ozone concentration is supplied to the clean substrate surface from which impurities are removed. Thereby, a thin oxide film of ozone water having an ozone concentration lower than the first ozone concentration is uniformly formed on the substrate surface.

  In addition, since the ozone water having the second ozone concentration is less oxidizable than the ozone water having the first ozone concentration and the rate of formation of the oxide film is slower, the oxidation formed by the ozone water having the first ozone concentration. It is possible to form a thin oxide film on the substrate with good controllability over the film.

  The supply of ozone water having the first ozone concentration to the substrate and the supply of hydrogen fluoride water to the substrate may be repeated. In this case, since ozone water and hydrogen fluoride water having the first ozone concentration are repeatedly supplied to the substrate, the formation of an oxide film by the ozone water having the first ozone concentration, organic substances present on the substrate surface, etc. Oxidation of these impurities and etching of impurities such as an oxide film and oxidized organic matter with hydrogen fluoride water are repeated, and the cleanliness of the substrate is further improved.

  After supplying ozone water having the second ozone concentration, the substrate may be stored in an atmosphere of a reducing gas or an inert gas. In this case, since the substrate is stored in an atmosphere of a reducing gas or an inert gas after supplying ozone water having the second ozone concentration to the substrate, the thin oxide film formed on the substrate is exposed to the atmosphere. Thickening is prevented.

  The first ozone concentration may be 5 ppm or more, and the second ozone concentration may be 1 ppm or less. In this case, when the first ozone concentration is 5 ppm or more, an oxide film can be easily formed on the substrate surface. Further, when the second ozone concentration is 1 ppm or less, a thin oxide film can be formed on the substrate surface with good controllability.

  The substrate processing apparatus which concerns on 2nd invention is the mixing means which produces | generates ozone water by mixing ozone and water, and the density | concentration of the ozone water produced | generated by a mixing means is 1st ozone concentration and 1st ozone. Adjusting means for adjusting to a second ozone concentration lower than the concentration, ozone water supply system for supplying ozone water of the first ozone concentration adjusted by the adjusting means to the substrate, and first ozone by the ozone water supply system A hydrogen fluoride water supply system for supplying hydrogen fluoride water to the substrate after supplying ozone water having a concentration, and the ozone water supply system is adjusted after the hydrogen fluoride water supply by the hydrogen fluoride water supply system The ozone water having the second ozone concentration adjusted by the means is supplied to the substrate.

  In the substrate processing apparatus according to the second invention, ozone and water are mixed by the mixing means to generate ozone water, and the concentration of the ozone water by the adjusting means is higher than the first ozone concentration and the first ozone concentration. It is adjusted to a low second ozone concentration. Thereby, ozone water with the first ozone concentration and the second ozone concentration can be obtained with a simple configuration.

  In addition, ozone water having a first ozone concentration is supplied to the substrate by the ozone water supply system, an oxide film is formed on the substrate surface, and impurities such as organic substances existing on the substrate surface are oxidized.

  Then, hydrogen fluoride water is supplied to the substrate by the hydrogen fluoride water supply system, and etching is performed. Thereby, impurities such as organic substances oxidized by ozone water having the first ozone concentration are removed together with the oxide film by lift-off.

  As described above, by supplying ozone water having the first ozone concentration and hydrogen fluoride water to the substrate, impurities such as organic substances existing on the substrate surface in advance are removed without requiring a cleaning process or the like. A clean substrate surface can be obtained by simple processing.

  Then, ozone water having a second ozone concentration lower than the first ozone concentration is supplied to the clean substrate surface from which impurities have been removed by the ozone water supply system. Thereby, a thin oxide film of ozone water having an ozone concentration lower than the first ozone concentration is uniformly formed on the substrate surface.

  In addition, since the ozone water having the second ozone concentration is less oxidizable than the ozone water having the first ozone concentration and the rate of formation of the oxide film is slower, the oxidation formed by the ozone water having the first ozone concentration. It is possible to form a thin oxide film on the substrate with good controllability over the film.

  The adjusting means may include a mixing ratio adjusting means for adjusting the concentration of ozone water by adjusting the mixing ratio of ozone and water supplied to the mixing means.

  In this case, the concentration of ozone water is adjusted by adjusting the mixing ratio of ozone and water supplied to the mixing means by the mixing ratio adjusting means. Thereby, ozone water having the first ozone concentration and ozone water having the second ozone concentration are easily produced.

  The adjusting unit may include a diluting unit that adjusts the concentration of ozone water by diluting the ozone water generated by the mixing unit. In this case, the concentration of ozone water generated by the mixing means is adjusted by the diluting means. Thereby, a simple configuration is realized.

  A first storage means for storing ozone water having the first ozone concentration adjusted by the adjustment means; and a second storage means for storing the second ozone water adjusted by the adjustment means. The ozone water supply system supplies ozone water having the first ozone concentration stored by the first storage means to the substrate, and the second ozone concentration stored by the second storage means Ozone water having the above may be supplied to the substrate.

  In this case, ozone water having the first ozone concentration adjusted by the adjusting means is stored by the first storing means, and the second ozone water adjusted by the adjusting means is stored by the second storing means.

  And the ozone water which has the 1st ozone concentration stored by the 1st storage means can be supplied to a board | substrate by an ozone water supply system. Furthermore, the ozone water having the second ozone concentration stored by the second storage means can be supplied to the substrate by the ozone water supply system.

  The first ozone concentration may be 5 ppm or more, and the second ozone concentration may be 1 ppm or less. In this case, when the first ozone concentration is 5 ppm or more, an oxide film can be easily formed on the substrate surface. Further, when the second ozone concentration is 1 ppm or less, a thin oxide film can be formed on the substrate surface with good controllability.

  In the substrate processing method according to the present invention, by supplying ozone water having the first ozone concentration to the substrate, an oxide film is formed on the substrate surface, and impurities such as organic substances existing on the substrate surface are oxidized. Is done.

  Etching is performed by supplying hydrogen fluoride water to the substrate. Thereby, impurities such as organic substances oxidized by ozone water having the first ozone concentration are removed together with the oxide film by lift-off.

  As described above, by supplying ozone water having the first ozone concentration and hydrogen fluoride water to the substrate, impurities such as organic substances existing on the substrate surface in advance are removed without requiring a cleaning process or the like. A clean substrate surface can be obtained by simple processing.

  Then, ozone water having a second ozone concentration lower than the first ozone concentration is supplied to the clean substrate surface from which impurities are removed. Thereby, a thin oxide film of ozone water having an ozone concentration lower than the first ozone concentration is uniformly formed on the substrate surface.

  In addition, since the ozone water having the second ozone concentration is less oxidizable than the ozone water having the first ozone concentration and the rate of formation of the oxide film is slower, the oxidation formed by the ozone water having the first ozone concentration. It is possible to form a thin oxide film on the substrate with good controllability over the film.

  Hereinafter, a substrate processing method and a substrate processing apparatus according to an embodiment of the present invention will be described with reference to FIGS.

  In the following description, a substrate refers to a semiconductor wafer, a glass substrate for a liquid crystal display device, a glass substrate for a PDP (plasma display panel), a glass substrate for a photomask, a substrate for an optical disk, and the like.

  FIG. 1 is a plan view of a substrate processing apparatus according to an embodiment of the present invention. As shown in FIG. 1, the substrate processing apparatus 100 has processing areas A and B, and a transfer area C between the processing areas A and B.

  In the processing area A, a control unit 4, fluid box units 2a and 2b, and cleaning processing units 5a and 5b are arranged.

  1 are pipes, joints, valves, flow meters, regulators, pumps, temperatures for supplying chemical solutions to the cleaning processing units 5a, 5b and draining liquid from the cleaning processing units 5a, 5b, respectively. Houses fluid-related equipment such as regulators and treatment liquid storage tanks. Specific configuration examples of the fluid box portions 2a and 2b and the cleaning processing portions 5a and 5b will be described later.

  In the cleaning processing units 5a and 5b, a cleaning process using a chemical solution (hereinafter referred to as a chemical process) is performed. In the present embodiment, the chemicals used in the cleaning processing units 5a and 5b are ozone water and hydrogen fluoride water.

  In the processing region B, fluid box portions 2c and 2d and cleaning processing portions 5c and 5d are arranged. Each of the fluid box portions 2c and 2d and the cleaning processing portions 5c and 5d has the same configuration as the fluid box portions 2a and 2b and the cleaning processing portions 5a and 5b, and the cleaning processing portions 5c and 5d are the cleaning processing portion 5a. , 5b.

  Hereinafter, the cleaning processing units 5a, 5b, 5c, and 5d are collectively referred to as processing units. In the transfer area C, a substrate transfer robot CR is provided.

  An indexer ID for carrying in and out the substrate W is arranged on one end side of the processing areas A and B, and the indexer robot IR is provided inside the indexer ID. The carrier 1 that stores the substrate W is placed on the indexer ID. In the present embodiment, a FOUP (Front Opening Unified Pod) that accommodates the substrate W in a sealed state is used as the carrier 1. However, the present invention is not limited to this, and a SMIF (Standard Mechanical Inter Face) pod is used. OC (Open Cassette) or the like may be used. Details of the carrier 1 will be described later.

  The indexer robot IR with the indexer ID moves in the direction of the arrow U, takes out the substrate W from the carrier 1 and passes it to the substrate transport robot CR, and conversely receives the substrate W subjected to a series of processing from the substrate transport robot CR. Return to carrier 1.

  The substrate transfer robot CR transfers the substrate W delivered from the indexer robot IR to the designated processing unit, or transfers the substrate W received from the processing unit to another processing unit or the indexer robot IR.

  In the present embodiment, after the chemical liquid processing is performed on the substrate W in any of the cleaning processing units 5a to 5d, the substrate W is unloaded from the cleaning processing units 5a to 5d by the substrate transport robot CR, and the indexer robot IR is moved. Via the carrier 1.

  The control unit 4 includes a computer including a CPU (Central Processing Unit) and the like. The operation of each processing unit in the processing areas A and B, the operation of the substrate transfer robot CR in the transfer area C, and the operation of the indexer robot IR of the indexer ID. To control. Details of the control unit 4 will be described later.

  FIG. 2 is a diagram for explaining the configuration of the cleaning processing units 5a to 5d of the substrate processing apparatus 100 according to the embodiment of the present invention.

  2 removes impurities such as organic substances adhering to the surface of the substrate W using the chemical solution supplied from the fluid box portions 2a to 2d (hereinafter referred to as contamination removal processing). A thin oxide film is formed on the surface of the clean substrate W (hereinafter referred to as an ultrathin oxide film formation process).

  Here, in the decontamination treatment, ozone water having a high ozone concentration (hereinafter referred to as high concentration ozone water) and hydrogen fluoride water are used. In addition, during the ultra-thin oxide film formation process, ozone water having a lower ozone concentration than the high-concentration ozone water (hereinafter referred to as low-concentration ozone water) is used. Details of the ozone concentration of high-concentration ozone water and low-concentration ozone water will be described later.

  As shown in FIG. 2, the cleaning processing units 5 a to 5 d include a spin chuck 21 for holding the substrate W horizontally and rotating the substrate W around a vertical rotation axis passing through the center of the substrate W. The spin chuck 21 is fixed to the upper end of the rotation shaft 25 rotated by the chuck rotation drive mechanism 36.

  The substrate W is rotated while being held horizontally by the spin chuck 21 when the contamination removal process and the ultrathin oxide film formation process are performed.

  A first rotation motor 60 is provided outside the spin chuck 21. A first rotation shaft 61 is connected to the first rotation motor 60. A first arm 62 is connected to the first rotation shaft 61 so as to extend in the horizontal direction, and an oxidation treatment nozzle 50 is provided at the tip of the first arm 62.

  The first rotation shaft 60 is rotated by the first rotation motor 60 and the first arm 62 is rotated, so that the oxidation processing nozzle 50 moves above the substrate W held by the spin chuck 21.

  An oxidation treatment supply pipe 63 is provided so as to pass through the inside of the first rotation motor 60, the first rotation shaft 61 and the first arm 62. The oxidation treatment supply pipe 63 is connected to the fluid box portions 2a to 2d.

  High-concentration ozone water or low-concentration ozone water is supplied from the fluid box portions 2a to 2d through the oxidation treatment supply pipe 63 to the oxidation treatment nozzles 50 of the cleaning treatment portions 5a to 5d. Thereby, high-concentration ozone water or low-concentration ozone water can be supplied to the surface of the substrate W.

  A second rotation motor 71 is provided outside the spin chuck 21. A second rotation shaft 72 is connected to the second rotation motor 71. A second arm 73 is connected to the second rotating shaft 72 so as to extend in the horizontal direction, and an etching nozzle 70 is provided at the tip of the second arm 73.

  The second rotation shaft 71 is rotated by the second rotation motor 71 and the second arm 73 is rotated, so that the etching nozzle 70 moves above the substrate W held by the spin chuck 21.

  An etching supply pipe 74 is provided so as to pass through the inside of the second rotation motor 71, the second rotation shaft 72, and the second arm 73. The etching supply pipe 74 is connected to the fluid box portions 2a to 2d.

  Hydrogen fluoride water is supplied from the fluid box portions 2 a to 2 d to the etching nozzles 70 of the cleaning processing portions 5 a to 5 d through the etching supply pipe 74. Thereby, hydrogen fluoride water can be supplied to the surface of the substrate W.

  When supplying high-concentration ozone water or low-concentration ozone water to the surface of the substrate W, the oxidation treatment nozzle 50 is positioned above the substrate W, and when supplying hydrogen fluoride water to the surface of the substrate W The oxidation treatment nozzle 50 is retracted to a predetermined position.

  When supplying high-concentration ozone water or low-concentration ozone water to the surface of the substrate W, the etching nozzle 70 is retracted to a predetermined position, and when supplying hydrogen fluoride water to the surface of the substrate W, The etching nozzle 70 is located above the substrate W.

  The spin chuck 21 is accommodated in the processing cup 23. A cylindrical partition wall 33 is provided inside the processing cup 23. Further, a drainage space 31 for draining the processing liquid (high concentration ozone water, low concentration ozone water or hydrogen fluoride water) used for processing the substrate W is formed so as to surround the periphery of the spin chuck 21. Has been. Further, a recovery liquid space 32 for recovering the processing liquid used for processing the substrate W is formed between the processing cup 23 and the partition wall 33 so as to surround the drainage space 31.

  A drainage pipe 34 is connected to the drainage space 31 to guide the processing liquid to a drainage processing apparatus (not shown), and the processing liquid is supplied to the recovery processing apparatus (not shown) in the recovery liquid space 32. A collection pipe 35 for guiding is connected.

  A guard 24 for preventing the processing liquid from the substrate W from splashing outward is provided above the processing cup 23. The guard 24 has a rotationally symmetric shape with respect to the rotation shaft 25. On the inner surface of the upper end of the guard 24, a drainage guide groove 41 having a square cross section is formed in an annular shape.

  Further, a recovery liquid guide portion 42 having an inclined surface that is inclined outward and downward is formed on the inner surface of the lower end portion of the guard 24. A partition wall storage groove 43 for receiving the partition wall 33 of the processing cup 23 is formed in the vicinity of the upper end of the recovered liquid guide portion 42.

  The guard 24 is provided with a guard raising / lowering drive mechanism (not shown) constituted by a ball screw mechanism or the like. The guard raising / lowering drive mechanism includes a guard 24, a recovery position where the recovery liquid guide 42 is opposed to the outer peripheral end surface of the substrate W held by the spin chuck 21, and the substrate W where the drainage guide groove 41 is held by the spin chuck 21. The liquid is moved up and down with respect to the drainage position facing the outer peripheral end face. When the guard 24 is in the recovery position (the guard position shown in FIG. 2), the processing liquid splashed outward from the substrate W is guided to the recovery liquid space 32 by the recovery liquid guide 42 and recovered through the recovery pipe 35. Is done. On the other hand, when the guard 24 is at the drainage position, the processing liquid splashed outward from the substrate W is guided to the drainage space 31 by the drainage guide groove 41 and drained through the drainage pipe 34. With the above configuration, the processing liquid is drained and collected.

  FIG. 3 is a view for explaining the configuration of the fluid box portions 2a to 2d of the substrate processing apparatus 100 according to the embodiment of the present invention.

  In the fluid box portions 2a to 2d, a high-concentration ozone water storage tank R1, a low-concentration ozone water storage tank R2, and a hydrogen fluoride water storage tank R3 are provided, an ozone concentration adjustment mechanism 200a, a pure water supply pipe 210, and ozone gas. A supply pipe 211, an ozone water supply pipe 220, a hydrogen fluoride water supply pipe 400, and a plurality of valves Va and Vb are provided.

  The pure water supply pipe 210 and the ozone gas supply pipe 211 are connected to the ozone concentration adjusting mechanism 200a. Pure water is supplied to the pure water supply pipe 210 through a pure water supply facility of a factory (not shown). The ozone gas supply pipe 211 is supplied with ozone gas through an ozone gas supply facility in a factory (not shown).

  Thereby, in the ozone concentration adjustment mechanism 200a, mixing of pure water and ozone gas is performed. During mixing of pure water and ozone gas, the ozone concentration adjusting mechanism 200a can easily produce high-concentration ozone water or low-concentration ozone water by adjusting the mixing ratio of pure water and ozone gas.

  Here, the ozone concentration adjusting mechanism 200a is constituted by, for example, a mixing valve or an inline mixer. Further, the ozone concentration of the high-concentration ozone water produced by the ozone concentration adjustment mechanism 200a is adjusted to 5 ppm or more, and the ozone concentration of the low-concentration ozone water produced by the ozone concentration adjustment mechanism 200a is adjusted to 1 ppm or less.

  An ozone water supply pipe 220 is connected to the ozone concentration adjusting mechanism 200a. The ozone water supply pipe 220 has a branch pipe 221, and a valve Vb is provided in the vicinity of the tip of the ozone water supply pipe 220 and in the vicinity of the tip of the branch pipe 221.

  The high concentration ozone water produced by the ozone concentration adjusting mechanism 200a is supplied to the high concentration ozone water storage tank R1 through the ozone water supply pipe 220. Thereby, a predetermined amount of high concentration ozone water is stored in the high concentration ozone water storage tank R1. A valve Va is provided at the lower end of the high-concentration ozone water storage tank R1.

  The low-concentration ozone water produced by the ozone concentration adjusting mechanism 200a is supplied to the low-concentration ozone water storage tank R2 through the ozone water supply pipe 220 and the branch pipe 221. Thereby, a predetermined amount of low concentration ozone water is stored in the low concentration ozone water storage tank R2. A valve Va is provided at the lower end of the low-concentration ozone water storage tank R2.

  Production of high-concentration ozone water or low-concentration ozone water by the ozone concentration adjusting mechanism 200a, supply of high-concentration ozone water to the high-concentration ozone water storage tank R1, and low-concentration ozone water storage tank R2 Is supplied by the controller 4 controlling the operations of the ozone concentration adjusting mechanism 200a and the plurality of valves Vb.

  The hydrogen fluoride water supply pipe 400 supplies hydrogen fluoride water to the hydrogen fluoride water storage tank R3 through a hydrogen fluoride water supply facility of a factory (not shown). Thereby, a predetermined amount of hydrogen fluoride water is stored in the hydrogen fluoride water storage tank R3. A valve Va is provided at the lower end of the hydrogen fluoride water storage tank R3. Further, a valve Vb is provided near the tip of the hydrogen fluoride water supply pipe 400. The supply of hydrogen fluoride water to the hydrogen fluoride water storage tank R3 is performed by the control unit 4 controlling the operation of the valve Vb provided in the hydrogen fluoride water supply pipe 400.

  Opening and closing of each of the plurality of valves Va is controlled by the control unit 4. As a result, the high-concentration ozone water stored in the high-concentration ozone water storage tank R1 or the low-concentration ozone water stored in the low-concentration ozone water storage tank R2 is oxidized by the cleaning treatment units 5a to 5d through the oxidation treatment supply pipe 63. The hydrogen fluoride water supplied to the processing nozzle 50 and stored in the hydrogen fluoride water storage tank R3 is supplied to the etching nozzles 70 of the cleaning processing units 5a to 5d through the oxidation processing supply pipe 63.

  In the ozone concentration adjusting mechanism 200a of FIG. 3, the ozone concentration is adjusted by adjusting the mixing ratio of the supplied ozone gas and pure water. Thereby, high concentration ozone water and low concentration ozone water are easily produced.

  In the present embodiment, the high-concentration ozone water storage tank R1 and the low-concentration ozone water storage tank R2 are connected to a common supply pipe 63 for oxidation treatment, and the high-concentration ozone water and the low-concentration ozone water stored in each of them. Are supplied from the common oxidation treatment nozzle 50 to the substrate W, but a supply system corresponding to each of the high-concentration ozone water storage tank R1 and the low-concentration ozone water storage tank R2 may be provided.

  In this case, for example, a supply pipe for supplying the high-concentration ozone water and the low-concentration ozone water to the cleaning treatment units 5a to 5d is provided in each of the high-concentration ozone water storage tank R1 and the low-concentration ozone water storage tank R2. In the cleaning processing units 5a to 5d, two sets of rotating motors, rotating shafts, arms, and nozzles are provided corresponding to the two supply pipes.

  In the present embodiment, the fluid box portions 2a to 2d of the substrate processing apparatus 100 may have the following configuration in addition to the configuration of FIG.

  FIG. 4 is a view for explaining another configuration of the fluid box portions 2a to 2d of the substrate processing apparatus 100 according to the embodiment of the present invention.

  The fluid box portions 2a to 2d in FIG. 4 are different from the fluid box portions 2a to 2d in FIG. 3 in the following points. 4, a high concentration ozone water storage tank R1, a low concentration ozone water storage tank R2, and a hydrogen fluoride water storage tank R3 are provided, and an ozone mixing mechanism 200b and a pure water supply pipe 210 are provided. 310, ozone gas supply pipe 211, ozone water supply pipes 230 and 320, dilution mechanism 300, hydrogen fluoride water supply pipe 400, and a plurality of valves Va and Vb.

  The ozone mixing mechanism 200b in FIG. 4 produces high-concentration ozone water having a predetermined ozone concentration by mixing pure water and ozone gas supplied from the pure water supply pipe 210 and the ozone gas supply pipe 211.

  The ozone mixing mechanism 200b is configured by, for example, a mixing valve or an inline mixer. Further, the ozone concentration of the high-concentration ozone water produced by the ozone mixing mechanism 200b is set to 5 ppm or more.

  An ozone water supply pipe 230 is connected to the ozone mixing mechanism 200b. The ozone water supply pipe 230 has a branch pipe 231, and a valve Vb is provided near the tip of the ozone water supply pipe 230. The branch pipe 231 is connected to the dilution mechanism 300.

  When the valve Vb of the ozone water supply pipe 230 is open, the high concentration ozone water produced by the ozone mixing mechanism 200b is supplied to the high concentration ozone water storage tank R1 through the ozone water supply pipe 230. Thereby, a predetermined amount of high concentration ozone water is stored in the high concentration ozone water storage tank R1.

  Further, when the valve Vb of the ozone water supply pipe 230 is closed, the high-concentration ozone water produced by the ozone mixing mechanism 200b is supplied to the dilution mechanism 300 through the ozone water supply pipe 230 and the branch pipe 231.

  A pure water supply pipe 310 is connected to the dilution mechanism 300. Pure water is supplied to the pure water supply pipe 310 through a pure water supply facility of a factory (not shown). Thereby, pure water is supplied to the dilution mechanism 300.

  The dilution mechanism 300 dilutes the high-concentration ozone water supplied from the branch pipe 231 with pure water supplied from the pure water supply pipe 310. Thereby, low concentration ozone water is produced. The ozone concentration of the low-concentration ozone water produced by the dilution mechanism 300 is set to 1 ppm or less.

  The dilution mechanism 300 is provided with an ozone water supply pipe 320. A valve Vb is provided near the lower end of the ozone water supply pipe 320. When the valve Vb is opened, the low-concentration ozone water produced by the dilution mechanism 300 is supplied to the low-concentration ozone water storage tank R2 through the ozone water supply pipe 320. Thereby, a predetermined amount of low concentration ozone water is stored in the low concentration ozone water storage tank R2.

  The dilution mechanism 300 is constituted by, for example, a mixing valve or an inline mixer.

  According to the dilution mechanism 300 of FIG. 4, the concentration of the high-concentration ozone water produced by the ozone mixing mechanism 200b is adjusted, and low-concentration ozone water is produced. Thereby, a simple configuration is realized.

FIG. 5 is a diagram for explaining the configuration of the carrier 1 of FIG. In the substrate processing apparatus 100 of FIG. 1, the substrate W that has been subjected to the contamination removal process and the ultrathin oxide film formation process is returned to the carrier 1. The inside of the carrier 1 in FIG. 1 is filled with a reducing gas or an inert gas. In this example, N ₂ (nitrogen) gas is used as the inert gas.

  As shown in FIG. 5, the carrier 1 capable of storing a plurality of substrates W is placed on the carrier placement table CD provided in the indexer ID of the substrate processing apparatus 100. In addition, an indexer robot IR is disposed inside the substrate processing apparatus 100 adjacent to the carrier mounting table CD.

Here, an N ₂ gas supply pipe 81 for supplying N ₂ gas into the carrier 1 is provided inside the carrier mounting table CD. The N ₂ gas supply pipe 81 is connected to an N ₂ gas supply source 80 such as a factory N ₂ gas supply facility. The tip of the N ₂ gas supply pipe 81 protrudes from the upper surface side (mounting surface of the carrier 1) of the carrier mounting table CD.

On the other hand, a gas supply mechanism 1 a is provided on a part of the lower surface side of the carrier 1. The gas supply mechanism 1a may be configured by, for example, a hinge 91 and a lid 92. In this case, one end of the lid 92 rotates around the hinge 91 as a central axis, so that the N ₂ gas supply port is opened or closed on the lower surface of the carrier 1.

Here, the tip of the N ₂ gas supply pipe 81 protruding from the carrier mounting table CD is provided so as to come into contact with the gas supply mechanism 1 a when the carrier 1 is mounted. As a result, when the carrier 1 is placed on the carrier placing table CD, the lid 92 of the carrier 1 comes into contact with the tip of the N ₂ gas supply pipe 81 and rotates around the hinge 91 to supply the N ₂ gas supply port. Is established.

As a result, the inside of the carrier 1 in which the plurality of substrates W are accommodated from the N ₂ gas supply pipe 81 is filled with N ₂ gas. Thus, the substrate W that has been subjected to the contamination removal process and the ultrathin oxide film formation process is stored in an N ₂ gas atmosphere.

Incidentally, in the substrate processing apparatus 100 of FIG. 1, the other stores the substrate W after the processing by the configuration of such a carrier 1, a buffer BF, as shown by a chain line in FIG. 1 is provided, N ₂ gas is filled The processed substrate W may be stored in the buffer BF.

  Here, details of the contamination removal process and the ultrathin oxide film formation process will be described. The processing procedure of the decontamination process is as follows.

  First, in the cleaning processing units 5 a to 5 d of FIG. 2, high-concentration ozone water is supplied from the oxidation nozzle 50 to the surface of the substrate W that rotates while being held by the spin chuck 21. As a result, an oxide film is formed on the surface of the substrate W, and impurities (contaminants on the surface of the substrate W) such as organic substances existing on the surface of the substrate W are oxidized.

  Subsequently, hydrogen fluoride water is supplied from the etching nozzle 70 to the surface of the substrate W supplied with ozone water. Thereby, the surface of the substrate W is etched. As a result, impurities such as organic substances oxidized by the high-concentration ozone water are removed together with the oxide film by lift-off. Thereby, a clean substrate W surface can be obtained.

  As described above, impurities such as organic substances existing on the surface of the substrate W in advance are removed without the need for a cleaning step or the like, so that a clean substrate W surface can be obtained by a simple process.

  Such a decontamination process is preferably repeated a plurality of times, such as twice or three times. By repeatedly performing the decontamination treatment, the oxide film was formed on the surface of the substrate W with high-concentration ozone water, the oxidation of impurities such as organic substances existing on the surface of the substrate W, and the oxide film and the oxide with hydrogen fluoride water were oxidized. Etching of impurities such as organic substances is repeated, and the cleanliness of the substrate W is further improved.

  On the other hand, the ultrathin oxide film forming process is performed by supplying low-concentration ozone water from the oxidation nozzle 50 to the clean substrate W surface that has been subjected to the contamination removal process. As a result, a thin oxide film of low-concentration ozone water is uniformly formed on the surface of the substrate W.

  Here, since low-concentration ozone water is less oxidizable than high-concentration ozone water and the rate of formation of the oxide film is slower, a thin oxide film with a better controllability than the oxide film formed by high-concentration ozone water is used as the substrate W. Can be formed.

In the substrate processing apparatus 100 of FIG. 1, the substrate W that has been subjected to the contamination removal process and the ultrathin oxide film formation process is stored in the carrier 1 of FIG. 5 or the buffer BF of FIG. 1. As a result, since the substrate W on which the thin oxide film is formed is stored in the N ₂ gas atmosphere, the thin oxide film formed on the substrate W is prevented from being thickened by exposure to the atmosphere.

  As described above, the ozone concentration of the high-concentration ozone water is 5 ppm or more, and the ozone concentration of the low-concentration ozone water is 1 ppm or less. Therefore, when the ozone concentration of the high-concentration ozone water is 5 ppm or more, an oxide film can be easily formed on the surface of the substrate W. Moreover, when the ozone concentration of the low-concentration ozone water is 1 ppm or less, a thin oxide film can be formed on the surface of the substrate W with good controllability.

  In the above embodiment, the control unit 4 controls the operations of the indexer robot IR and the substrate transfer robot CR in FIG. 1 and controls the components of the cleaning processing units 5a to 5d and the fluid box units 2a to 2d. .

  In particular, in the cleaning processing units 5a to 5d, the control unit 4 controls operations of the chuck rotation drive mechanism 36, the first rotation motor 60, the second rotation motor 71, the guard lifting / lowering drive mechanism, and the like.

  In addition, in the fluid box portions 2a to 2d of FIG. 3, the control portion 4 operates at the lower end of each of the operations of the ozone concentration adjusting mechanism 200a, the oxygen water storage tank R1, the ozone water storage tank R2, and the hydrogen fluoride water storage tank R3. Control of opening / closing of the provided valve Va and opening / closing of the valve Vb provided in each of the ozone water supply pipe 220, the branch pipe 221 and the hydrogen fluoride water supply pipe 400 are controlled.

  Further, in the fluid box units 2a to 2d of FIG. 4, the control unit 4 operates the ozone mixing mechanism 200b and the dilution mechanism 300, the oxygen water storage tank R1, the ozone water storage tank R2, and the hydrogen fluoride water storage tank R3, respectively. And the opening / closing of the valve Va provided in each of the ozone water supply pipes 230 and 320 and the hydrogen fluoride water supply pipe 400 are controlled.

  As described above, in substrate processing apparatus 100 according to the present embodiment, high-concentration ozone water and low-concentration ozone water can be obtained with a simple configuration.

  Further, the high-concentration ozone water stored in the high-concentration ozone water storage tank R1 is supplied to the surface of the substrate W through the oxidation treatment supply pipe 63 and the oxidation treatment nozzle 50, whereby an oxide film is formed on the surface of the substrate W. At the same time, impurities such as organic substances existing on the surface of the substrate W are oxidized.

  Etching is performed by supplying the hydrogen fluoride water stored in the hydrogen fluoride water storage tank R <b> 3 to the surface of the substrate W through the etching supply pipe 74 and the etching nozzle 70. Thereby, impurities such as organic matter oxidized by the high-concentration ozone water are removed together with the oxide film by lift-off.

  By performing the decontamination process in this way, impurities such as organic substances existing on the surface of the substrate W in advance are removed without requiring a cleaning process or the like, so that a clean substrate W surface can be obtained by a simple process. it can. Furthermore, a more clean substrate W surface can be obtained by repeatedly performing the decontamination process a plurality of times.

  Then, the low concentration ozone water stored in the low concentration ozone water storage tank R2 is supplied to the clean substrate W surface subjected to the decontamination treatment, so that the ozone concentration is lower than the ozone concentration of the high concentration ozone water. A thin oxide film made of low-concentration ozone water is uniformly formed on the surface of the substrate W.

  Low-concentration ozone water is less oxidizable than high-concentration ozone water, and the rate of formation of the oxide film is slower, so a thin oxide film is formed on the substrate W with good control over the oxide film formed by high-concentration ozone water. It is possible.

  As described above, in one embodiment of the present invention, the decontamination process includes supplying ozone water having a first ozone concentration to the substrate, and supplying hydrogen fluoride water to the substrate after supplying ozone water having the first ozone concentration. The ultrathin oxide film forming process corresponds to a step of supplying ozone water having a second ozone concentration lower than the first ozone concentration to the substrate after supplying hydrogen fluoride water. The high-concentration ozone water corresponds to ozone water having a first ozone concentration, and the low-concentration ozone water corresponds to ozone water having a second ozone concentration.

  The valve Va, the oxidation treatment nozzle 50 and the oxidation treatment supply pipe 63 correspond to an ozone water supply system, and the valve Va, the etching nozzle 70 and the etching supply pipe 74 correspond to a hydrogen fluoride water supply system. In addition, the ozone concentration adjustment mechanism 200a and the dilution mechanism 300 correspond to adjustment means, the ozone mixing mechanism 200b corresponds to mixing means, and the dilution mechanism 300 corresponds to dilution means.

  Furthermore, the high-concentration ozone water storage tank R1 corresponds to the first storage means, and the low-concentration ozone water storage tank R2 corresponds to the second storage means.

  The substrate processing method and the substrate processing apparatus according to the present invention can be used for forming an oxide film on a substrate such as a semiconductor wafer, a glass substrate for a photomask, a glass substrate for a liquid crystal display device, and a glass substrate for an optical disk. .

1 is a plan view of a substrate processing apparatus according to an embodiment of the present invention. It is a figure for demonstrating the structure of the cleaning process part of the substrate processing apparatus which concerns on one embodiment of this invention. It is a figure for demonstrating the structure of the fluid box part of the substrate processing apparatus which concerns on one embodiment of this invention. It is a figure for demonstrating the other structure of the fluid box part of the substrate processing apparatus which concerns on one embodiment of this invention. It is a figure for demonstrating the structure of the carrier of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Substrate processing apparatus 50 Oxidation processing nozzle 63 Oxidation processing supply pipe 70 Etching nozzle 74 Etching supply pipe 200a Ozone concentration adjustment mechanism 200b Ozone mixing mechanism 300 Dilution mechanism R1 High concentration ozone water storage tank R2 Low concentration ozone water storage tank Va valve

Claims (9)

A substrate processing method for performing predetermined processing on a substrate,
Supplying ozone water having a first ozone concentration to the substrate;
Supplying hydrogen fluoride water to the substrate after supplying ozone water having the first ozone concentration;
And a step of supplying ozone water having a second ozone concentration lower than the first ozone concentration to the substrate after the supply of hydrogen fluoride water. The substrate processing method according to claim 1, wherein supply of ozone water having the first ozone concentration to the substrate and supply of hydrogen fluoride water to the substrate are repeated. 3. The substrate processing method according to claim 1, further comprising a step of storing the substrate in an atmosphere of a reducing gas or an inert gas after supplying the ozone water having the second ozone concentration. The first ozone concentration is 5 ppm or more;
The substrate processing method according to claim 1, wherein the second ozone concentration is 1 ppm or less. Mixing means for generating ozone water by mixing ozone and water;
Adjusting means for adjusting the concentration of ozone water generated by the mixing means to a first ozone concentration and a second ozone concentration lower than the first ozone concentration;
An ozone water supply system that supplies the substrate with ozone water having the first ozone concentration adjusted by the adjusting means;
A hydrogen fluoride water supply system for supplying hydrogen fluoride water to the substrate after the ozone water having the first ozone concentration is supplied by the ozone water supply system;
The ozone water supply system supplies ozone water having the second ozone concentration adjusted by the adjusting means to the substrate after supplying hydrogen fluoride water by the hydrogen fluoride water supply system. Processing equipment. The adjusting means includes
6. The substrate processing apparatus according to claim 5, further comprising a mixing ratio adjusting means for adjusting a concentration of ozone water by adjusting a mixing ratio of ozone and water supplied to the mixing means. The adjusting means includes
6. The substrate processing apparatus according to claim 5, further comprising dilution means for adjusting the concentration of ozone water by diluting the ozone water generated by the mixing means. First storage means for storing ozone water having the first ozone concentration adjusted by the adjustment means;
A second storage means for storing the second ozone water adjusted by the adjustment means;
The ozone water supply system supplies the substrate with ozone water having the first ozone concentration stored by the first storage means, and has the second ozone concentration stored by the second storage means. The substrate processing apparatus according to claim 5, wherein ozone water is supplied to the substrate. The first ozone concentration is 5 ppm or more;
The substrate processing apparatus according to claim 5, wherein the second ozone concentration is 1 ppm or less.

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