Substrate processing apparatus and substrate processing method

Abstract

The present invention provides a substrate processing apparatus and a substrate processing method that can suppress product defects by protecting the exposed areas after etching with an oxide film. [Solution] The substrate processing apparatus 1 of the embodiment includes a rotating body 10 that holds and rotates a substrate W, a first processing liquid supply unit 40 that performs etching by supplying a first processing liquid for etching to the surface of the substrate W to be processed which is rotated by the rotating body 10, and a second processing liquid supply unit 50 that performs oxide film formation by supplying a second processing liquid for oxidation to the surface of the substrate W to be processed which is rotated by the rotating body 10, in succession to the etching by supplying the first processing liquid.

Description

Technical Field

[0001] The present invention relates to a substrate processing apparatus and a substrate processing method. Background Art

[0002] As a wet etching apparatus that etches a film stacked on a substrate such as a semiconductor wafer with a processing liquid, there is a batch-type substrate processing apparatus that collectively immerses a plurality of substrates in the processing liquid. Such a batch-type substrate processing apparatus can process a plurality of substrates collectively, and thus has high productivity.

[0003] However, in a batch-type substrate processing apparatus, since a plurality of substrates are immersed in a processing liquid under common conditions, it is difficult to finely adjust the etching depth and the like for each substrate according to differences in film thickness and the like formed on each substrate. Accordingly, a single-wafer-type substrate processing apparatus that processes substrates one by one is used, in which a processing liquid for etching is supplied near the rotation center of the substrate while rotating the substrate, and the processing liquid is spread over the surface of the substrate.

[0004] As the processing liquid for etching, acid-based liquids such as hydrofluoric acid, phosphoric acid, and sulfuric acid are used. For example, when etching a silicon nitride (SiN) film as a target film in a substrate in which a natural oxide film (SiO₂) is formed on polysilicon (Poly-Si) of a silicon wafer due to contact with the atmosphere, and further has a portion where a silicon nitride film is stacked, there is a substrate processing apparatus that uses phosphoric acid as the processing liquid.

[0005] As described above, in a substrate processing apparatus that performs etching with a processing liquid containing phosphoric acid, it is necessary to secure an etching selectivity between an oxide film and a nitride film, that is, to suppress etching of the underlying oxide film while etching the nitride film. To address this, there is a method of mixing a predetermined amount of colloidal silica into the processing liquid. According to this method, the overall etching rate is reduced, so that the oxide film becomes difficult to be etched. Prior Art Documents Patent Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2012-74601 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, even with methods that reduce the overall etching rate, the oxide film is still etched to some extent. In particular, in areas where the oxide film beneath the nitride film is thin, the oxide film may be completely removed, exposing the polysilicon beneath the oxide film. Furthermore, in areas where no oxide film has formed beneath the nitride film in the first place, the etching of the nitride film will expose the polysilicon.

[0008] After etching, a rinsing process is performed using warm pure water or an APM treatment solution (a mixture of ammonia water and hydrogen peroxide water), which is an alkaline solution, to remove the treatment solution containing phosphoric acid. However, if the polysilicon is exposed during this cleaning process, the exposed polysilicon will be etched by the heat from the warm pure water and the APM treatment solution. In other words, materials other than the target film to be etched will also be etched, leading to product defects.

[0009] Embodiments of the present invention have been proposed to solve the above-mentioned problems, and their objective is to provide a substrate processing apparatus and a substrate processing method that can suppress product defects by protecting the exposed portion after etching with an oxide film. [Means for solving the problem]

[0010] The substrate processing apparatus according to an embodiment of the present invention includes a rotating body for holding and rotating a substrate, a first processing liquid supply unit for performing etching by supplying a first processing liquid for etching to the surface of the substrate to be processed which is rotated by the rotating body, and a second processing liquid supply unit for performing oxide film formation by supplying a second processing liquid for oxidation to the surface of the substrate to be processed which is rotated by the rotating body after the etching process by supplying the first processing liquid.

[0011] The substrate processing method according to an embodiment of the present invention involves holding and rotating a substrate with a rotating body, supplying a first processing solution for etching to the surface of the substrate to be processed which is rotating with the rotating body, and supplying a second processing solution for oxidation to the surface of the substrate to be processed which is rotating with the rotating body. [Effects of the Invention]

[0012] Embodiments of the present invention provide a substrate processing apparatus and a substrate processing method that can suppress product defects by protecting the exposed portion after etching with an oxide film. [Brief explanation of the drawing]

[0013] [Figure 1] This diagram shows the overall configuration of the substrate processing apparatus according to the embodiment. [Figure 2] This is an explanatory diagram showing the oxide film formation process of the substrate processing apparatus according to the embodiment. [Figure 3] Figure 1 is a partial cross-sectional side view showing the etching apparatus of the substrate processing apparatus. [Figure 4] Figure 3 is a plan view showing the operation of the holding part of the etching apparatus. [Figure 5] Figure 3 is a plan view showing the processing solution holding section of the etching apparatus. [Figure 6] Figure 3 is an explanatory diagram showing the supply operation of the second processing solution in the etching apparatus. [Figure 7] This is a flowchart showing the processing procedure of the substrate processing apparatus according to the embodiment. [Figure 8] This figure shows a modified example of the substrate processing apparatus of the embodiment. [Modes for carrying out the invention]

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [overview] As shown in Figure 1, the substrate processing apparatus 1 of this embodiment is a single-wafer processing apparatus that comprises a plurality of chambers 1a housing various processing devices, and processes substrates W that have been transported in multiple quantities in a cassette (FOUP) 1b in the previous process, one by one in each chamber 1a. Unprocessed substrates W are taken out one by one from the cassette 1b by a transport robot 1c, temporarily placed on a buffer unit 1d, and then transported to each chamber 1a and processed by the various devices described below.

[0015] The substrate processing apparatus 1 includes an etching apparatus 110, a cleaning apparatus 120, a transport apparatus 200, a drying apparatus 300, and a control device 400. The etching apparatus 110 is a device that removes a portion of the target film by supplying an etching solution to the surface of a rotating substrate W to be processed, leaving the necessary film. The cleaning apparatus 120 cleans the processed surface of the substrate W that has been etched by the etching apparatus 110 by supplying a cleaning solution. As will be described later, the etching apparatus 110 also performs a cleaning process by supplying a cleaning solution, but this is a different cleaning process from the cleaning performed by the cleaning apparatus 120, which is performed in a different chamber (second chamber) 1a from the chamber (first chamber) 1a of the etching apparatus 110.

[0016] The transfer device 200 transfers the substrate W between the buffer unit 1d and each chamber 1a, and between respective chambers 1a. For example, the transfer device 200 transfers a substrate W processed by the etching device 110 to the cleaning device 120, and transfers the substrate W cleaned by the cleaning device 120 to the drying device 300. The transfer device 200 also includes a robot hand 210 that grips the substrate W, and a transfer robot 220 that moves the robot hand 210. The drying device 300 performs a drying process by heating the cleaned substrate W while rotating it. The control device 400 controls each of the aforementioned devices.

[0017] Note that the substrate W processed according to the present embodiment is, for example, a semiconductor wafer. Hereinafter, the surface of the substrate W on which a pattern or the like is formed is referred to as a surface to be processed. As shown in FIG. 2(A), the surface to be processed has a portion where polysilicon 101, a silicon oxide film 102, and a silicon nitride film 103 are stacked in this order on a silicon wafer 100. Hereinafter, the silicon oxide film 102 is simply referred to as the oxide film 102, and the silicon nitride film 103 is simply referred to as the nitride film 103.

[0018] The target film to be etched is the nitride film 103. The oxide film 102 is a film naturally formed by contact with the atmosphere, and functions as a protective film for protecting the polysilicon 101, but there are also locations where the oxide film 102 is not formed. Etching is performed on a part of the nitride film 103, and it is desirable to suppress etching of the oxide film 102 as much as possible, so that the retained oxide film 102 protects the polysilicon 101 during cleaning. However, as described above, the oxide film 102 is easily removed during etching (see FIG. 2(B)). Note that the layer to be protected is not limited to the polysilicon 101, and may be epitaxial silicon or the like; in the case of the silicon wafer 100, all types of silicon are targeted.

[0019] A treatment liquid for etching processing (first treatment liquid) is an aqueous solution containing phosphoric acid (H3PO4) (hereinafter referred to as a phosphoric acid solution). In this embodiment, after the etching process, a treatment liquid for oxide film formation processing (second treatment liquid) is supplied to the processing target surface of the rotating substrate W to intentionally oxidize the processing target surface. This serves to compensate for the removed oxide film 102 to maintain the function as a protective film (see FIG. 2(C)), and also to form an oxide film 102 where none existed to enhance the function as a protective film. As the second treatment liquid for the oxide film formation processing, hydrogen peroxide water (H2O2) or ozone (O3) water is used.

[0020] In the cleaning apparatus 120, an alkaline cleaning solution (APM), ultrapure water (DIW), and a volatile solvent (IPA) are used as treatment liquids for cleaning (rinsing) processing. APM is a chemical solution obtained by mixing ammonia water and hydrogen peroxide water, and is used to remove residual organic matter. DIW is used to wash away APM remaining on the processing target surface of the substrate W after APM processing. IPA has lower surface tension than DIW and higher volatility, so it is used to replace DIW to reduce pattern collapse caused by surface tension. Note that the etching apparatus 110 of this embodiment uses carbonated water (CO2W) for cleaning before etching processing, and uses hot pure water (Hot DIW) for cleaning after oxide film formation.

[0021] Each processing unit of this embodiment processes the processing target surface of the substrate W by supplying the treatment liquid to the processing target surface while rotating the substrate W together with the rotating body 10. The etching apparatus 110 will be mainly described below.

[0022] [Etching Apparatus] As shown in FIGS. 3 to 5, the etching apparatus 110 includes a rotating body 10, a rotating mechanism 20, a holding unit 30, a first treatment liquid supply unit 40, a second treatment liquid supply unit 50, and a control unit 60. Note that in FIG. 3, the illustration of chamber 1a (first chamber), which accommodates the rotating body 10, the rotating mechanism 20, and the holding unit 30 and in which the etching processing and the oxide film formation processing are performed, is omitted.

[0023] (Rotating body) The rotating body 10 has an opposing surface 111 that is spaced apart from the substrate W held by the holding part 30, and is rotatably mounted together with the holding part 30. The rotating body 10 has a table 11 and a base 12. The table 11 is cylindrical in shape with one end closed by the opposing surface 111. The opposing surface 111 is a circular surface with a diameter larger than that of the substrate W. A circular through hole 11a is formed in the center of the opposing surface 111 (see Figure 4). An outlet 11b, which is a through hole for discharging the processing liquid, is formed on the side surface 112 of the table 11.

[0024] The base 12 is a cylindrical member having the same diameter as the table 11 and connected to the opposite side of the opposing surface 111. The base 12 is a member having a structure that supports the table 11. The table 11 and base 12 that constitute the rotating body 10 are made of a material that is resistant to the processing liquid. For example, it is preferable to construct the rotating body 10 from a fluororesin such as PTFE or PCTFE.

[0025] The rotating body 10 is rotatably mounted on a fixed base 13 fixed to an installation surface (not shown) or a frame installed on the installation surface, by a rotating mechanism 20 described later. The fixed base 13 is provided with a protective wall 13a. The protective wall 13a is concentric with the base 12 and is a double cylindrical wall rising on the fixed base 13, covering the lower edge of the base 12 by sandwiching it without contact. As a result, a labyrinth structure, which is a curved path, is formed between the protective wall 13a and the base 12, making it difficult for the processing liquid flowing down along the outer wall of the base 12 to flow into the interior of the base 12.

[0026] Furthermore, a cup 14 is provided around the rotating body 10 inside the chamber 1a to receive various processing liquids scattered from the rotating substrate W from around the substrate W.

[0027] (Rotation mechanism) The rotating mechanism 20 is a mechanism for rotating the rotating body 10. The rotating mechanism 20 has a fixed shaft 21 and a drive source 22. The fixed shaft 21 is a cylindrical member arranged coaxially with the rotating body 10. The lower end of the fixed shaft 21 is fixed to the fixed base 13 together with the drive source 22, which will be described later.

[0028] The drive source 22 is a hollow motor having a hollow rotor and a stator that rotates it. The drive source 22 is fixed to the fixed base 13 together with the fixed shaft 21. The drive source 22 rotates the table 11 together with the base 12 by energizing the coils of the stator, which causes the rotor to rotate.

[0029] (holding part) The holding portion 30 holds the substrate W parallel to and spaced apart from the opposing surface 111. As shown in Figure 4, the holding portion 30 includes a rotating member 31, a holding pin 32, and a drive mechanism 33. The rotating member 31 is a plurality of cylindrical members arranged at equal intervals along the periphery of the substrate W. The rotating member 31 is provided so as to be rotatable about an axis parallel to the fixed shaft 21. The top surface of the rotating member 31 is exposed from the opposing surface 111.

[0030] The retaining pin 32 is erected at an eccentric position from the center of rotation of the top surface of the rotating member 31. The retaining pin 32 is cylindrical and has a constriction into which the edge of the substrate W fits. As the rotating member 31 rotates, the retaining pin 32 moves between a retaining position (see Figure 4(A)) in which it holds the substrate W by contacting the edge of the substrate W, and a release position (see Figure 4(B)) in which it releases the substrate W by moving away from the edge of the substrate W.

[0031] The drive mechanism 33 moves the retaining pin 32 between a retaining position and a released position by rotating the rotating member 31. The drive mechanism 33 includes a drive shaft 331, a small gear 332, and a large gear 333.

[0032] The drive shaft 331 is a cylindrical member provided on the opposite side of the top surface of the rotating member 31, coaxially with the axis of rotation of the rotating member 31. The small gear 332 is a sector gear provided at the end of the drive shaft 331 opposite to the rotating member 31. The large gear 333 is a gear with intermittently formed gear grooves corresponding to the small gear 332. The large gear 333 is rotatably mounted within the base 12 by bearings (not shown). The large gear 333 has six protrusions formed at predetermined intervals in the circumferential direction, corresponding to the intervals of the small gear 332, and gear grooves that mesh with the small gear 332 are formed on the outer circumferential surface of the tip of each protrusion.

[0033] The large gear 333 is biased in the rotational direction (counterclockwise) indicated by arrow α in Figure 4(A) by a biasing member such as a spring (not shown). As a result, the small gear 332 is biased in the clockwise direction indicated by arrow β1, so that the rotating member 31 is linked to the rotation of the small gear 332, and the retaining pin 32 moves toward the center of the rotating body 10 and is maintained in a retaining position that contacts the substrate W. During substrate processing, the rotating member 31, drive shaft 331, retaining pin 32, small gear 332, and large gear 333 rotate together with the rotating body 10 while maintaining this retaining position.

[0034] Furthermore, the rotation of the large gear 333 is prevented by a stopper mechanism (not shown). With the rotation of the large gear 333 prevented, when the rotating body 10 is rotated in the direction of arrow γ, as shown in Figure 4(B), the small gear 332, which is meshed with the large gear 333 whose rotation is prevented, rotates in the counterclockwise direction indicated by arrow β2. As a result, the rotating member 31 rotates, causing the retaining pin 32 to move away from the edge of the substrate W and into the release position.

[0035] (First processing liquid supply unit) As shown in Figure 3, the first processing liquid supply unit 40 performs etching by supplying a first processing liquid for etching to the surface of the substrate W to be processed, that is, the surface of the substrate W opposite to the opposing surface 111 held by the holding unit 30. The first processing liquid supply unit 40 includes a processing liquid supply mechanism 41, a processing liquid holding unit 42, a lifting mechanism 43, and a heating unit 44.

[0036] The processing liquid supply mechanism 41 has supply units 411, 412, and 413 that supply three types of processing liquids. Supply unit 411 supplies carbonated water as the processing liquid. Supply unit 412 supplies phosphoric acid solution as the processing liquid. This phosphoric acid solution is the first processing liquid for etching. Supply unit 413 supplies warm pure water. Supply units 411, 412, and 413 each have a processing liquid tank 41a for storing their respective processing liquids. Carbonated water and warm pure water are cleaning liquids for the rinsing process. For this reason, a part of the first processing liquid supply unit 40 in this embodiment is configured as a cleaning liquid supply unit.

[0037] Individual supply pipes 41b are connected in parallel to the processing liquid supply pipe 41c from each processing liquid tank 41a. The tip of the processing liquid supply pipe 41c faces the substrate W held by the holding part 30. As a result, the processing liquid from each processing liquid tank 41a is supplied to the surface of the substrate W via the individual supply pipes 41b and the processing liquid supply pipe 41c.

[0038] Each individual supply pipe 41b is equipped with a flow control valve 41d and a flow meter 41e. By adjusting each flow control valve 41d, the amount of processed liquid flowing from the corresponding processed liquid tank 41a to the processed liquid supply pipe 41c is adjusted. The amount of processed liquid flowing through each individual supply pipe 41b is detected by the corresponding flow meter 41e. The equipment and method for generating the processed liquid stored in each processed liquid tank 41a are not limited to any specific type.

[0039] The processing liquid holding section 42 is positioned close to the substrate W and holds the processing liquid between itself and the substrate W. The processing liquid holding section 42 is circular in diameter larger than the substrate W, and has a basin shape formed by a wall rising on the periphery opposite to the rotating body 10. The processing liquid holding section 42 has a double structure to achieve both heat resistance and liquid resistance. That is, the base is formed of a heat-resistant material, and its periphery is covered with a material resistant to the processing liquid. For example, it is preferable that the processing liquid holding section 42 is constructed by using quartz as the base and forming a cover of a fluorine-based resin such as PTFE or PCTFE around it. The outer bottom surface of the processing liquid holding section 42 faces the substrate W.

[0040] The tip of the processing liquid supply pipe 41c is inserted through the processing liquid holding section 42, forming a discharge port 42a that is exposed to the substrate W side. As shown in Figure 5, the discharge port 42a is offset from the axis of rotation of the rotating body 10. This is to contribute to the uniformity of the processing liquid temperature by sequentially changing the portion of the substrate W facing the discharge port 42a as the substrate W rotates.

[0041] The lifting mechanism 43 is a mechanism that moves the processing liquid holding section 42 in a direction toward or toward the substrate W. Various mechanisms that move the processing liquid holding section 42 in a direction parallel to the axis of the rotating body 10 can be applied as the lifting mechanism 43, for example, a cylinder or a ball screw mechanism, but details are omitted.

[0042] A gap D1 is provided between the processing liquid holding unit 42, which is waiting above, and the opposing surface 111, allowing the substrate W supported by the robot hand 210 to be fed in, while also not obstructing the ejection of the second processing liquid by the second processing liquid supply unit 50, which will be described later. The lifting mechanism 43 lowers the processing liquid holding unit 42 to a position where a gap D2 is formed between it and the surface of the substrate W. This gap D2 is, for example, 4 mm or less, but the processing liquid holding unit 42 and the substrate W are kept in non-contact so that the processing liquid can flow.

[0043] The heating unit 44 heats the processing liquid supplied onto the surface of the substrate W to be processed by the first processing liquid supply unit 40. The heating unit 44 has a heater 441 provided on the side of the processing liquid holding unit 42 opposite to the side facing the substrate W. As a result, the heating unit 44 moves up and down relative to the substrate W together with the processing liquid holding unit 42 by the lifting mechanism 43. The heater 441 is in the shape of a circular sheet. The heater 441 is composed of, for example, three heater pieces, the amount of heat generated can be controlled individually. That is, two annular heater pieces are arranged concentrically around the outside of a circular heater piece. With such a heater 441, the temperature of the processing liquid can be changed for each concentric section by individually controlling the amount of heat generated by the three concentrically arranged heater pieces. The diameter of the heating unit 44 is preferably equal to or larger than the diameter of the substrate W in order to suppress the temperature drop on the outer circumference side of the substrate W.

[0044] The heater 441 has a through-hole 441a through which the processing liquid supply pipe 41c is inserted. The position of the through-hole 441a is adjacent to and continuous with the discharge port 42a of the processing liquid holding section 42, and is offset from the axis of the rotating body 10. The processing liquid is heated to a preset temperature by a heating device (not shown) in the first processing liquid supply section 40, supplied to the substrate W, and heated by the heating section 44. This allows the processing liquid supplied to the substrate W to spread across the entire surface of the substrate W while maintaining the preset temperature. In particular, by making the heater 441 on the outer periphery side hotter, the effect of raising the temperature of the outer periphery of the substrate W, which tends to cool down easily, can be obtained.

[0045] (Second processing liquid supply unit) The second processing liquid supply unit 50 performs an oxide film formation treatment by supplying a second processing liquid for oxidation treatment to the surface of the substrate W to be treated. This supply of the second processing liquid is performed in succession to the etching treatment described above. The second processing liquid supply unit 50 has a supply nozzle 51 and a mass flow controller (hereinafter referred to as MFC) 52. The supply nozzle 51 supplies hydrogen peroxide water, which is the second processing liquid, as the second processing liquid. As described above, ozonated water can also be used as the second processing liquid. As shown in Figures 6(A) and (B), the supply nozzle 51 is installed near the outer edge of the rotating body 10 in the chamber 1a, in a position that does not interfere with the vertically moving processing liquid holding unit 42. The supply nozzles 51 are provided in pairs, with one tip pointing toward the center of the substrate W and the other tip pointing toward the outer circumference of the substrate W.

[0046] MFC52 is an adjustment unit that individually adjusts the amount of the second processing liquid supplied per unit time in the piping connected between the second processing liquid supply device and the supply nozzle 51. MFC52 has a mass flow meter for measuring the fluid flow rate and a solenoid valve for controlling the flow rate.

[0047] (Control Unit) The control unit 60 controls each part of the substrate processing apparatus 1. The control unit 60 has a processor that executes programs to realize various functions of the substrate processing apparatus 1, a memory that stores various information such as programs and operating conditions, and drive circuits that drive each element. In other words, the control unit 60 controls the rotating mechanism 20, the processing liquid supply mechanism 41, the lifting mechanism 43, the heating unit 44, the MFC 52, and so on.

[0048] In this embodiment, the control unit 60 rotates the substrate W together with the rotating body 10 using the rotating mechanism 20, and supplies the first processing liquid to the surface of the substrate W using the processing liquid supply mechanism 41 to perform etching. As shown in Figure 6(B), immediately following the etching process, the control unit 60 ejects the second processing liquid from the supply nozzle 51 toward the center and outer circumference of the rotating substrate W to perform oxide film formation. The amount of the second processing liquid supplied can be controlled by the control unit 60 by controlling the MFC 52. In other words, the control unit 60 discharges the first processing liquid from the discharge port 42a and brings the heating unit 44 closer to the substrate W to heat the first processing liquid and perform etching. Immediately following the etching process, the heating unit 44 is moved away, and the second processing liquid is discharged from the supply nozzle 51 toward the center of the substrate W.

[0049] [Operation] The operation of the substrate processing apparatus 1 of this embodiment will be explained with reference to the flowchart in Figure 7, in addition to Figures 1 to 6 above. Note that a substrate processing method that processes the substrate W according to the following procedure is also one aspect of this embodiment.

[0050] First, as shown in Figure 3, the processing liquid holding unit 42 of the first processing liquid supply unit 40 is in an upper standby position. At this time, a gap D1 is provided between the processing liquid holding unit 42 and the opposing surface 111, allowing the substrate W supported by the robot hand 210 (see Figure 1) of the transport device 200 to be loaded. In addition, a gap d1 is provided between the back surface of the substrate W and the opposing surface 111, allowing the robot hand 210 supporting the substrate W to be inserted. In other words, the robot hand 210 does not get in the way when loading and unloading the substrate W, or when it is inserted between the back surface of the substrate W and the rotating body 10.

[0051] Furthermore, by pre-energizing the heater 441, the side of the processing liquid holding section 42 opposite to the side facing the substrate W is heated, and the processing liquid holding section 42 is maintained at a predetermined temperature (for example, a temperature within the temperature range of 180°C to 225°C).

[0052] In this state, as shown in Figure 3, the substrate W mounted on the robot hand 210 is moved between the processing liquid holding unit 42 and the rotating body 10, and as shown in Figure 4(A), its periphery is supported by a plurality of holding pins 32, thereby holding it on the opposing surface 111 of the rotating body 10 (step S01). At this time, the substrate W is positioned so that its center coincides with the axis of rotation of the rotating body 10.

[0053] Next, the rotating body 10 rotates at a relatively high predetermined speed (for example, about 200-300 rpm). As a result, the substrate W rotates together with the holding unit 30 at the predetermined speed (step S02). Then, carbonated water is supplied to the surface of the substrate W from the discharge port 42a of the processing liquid holding unit 42 (step S03). As carbonated water is supplied to the surface of the rotating substrate W, the carbonated water moves sequentially toward the outer circumference of the substrate W, thereby cleaning the surface of the substrate W. After a predetermined processing time has elapsed, the processing liquid holding unit 42 stops supplying carbonated water (step S04).

[0054] As shown in Figure 6(A), the processing liquid holding unit 42 descends to a position where a predetermined gap D2 (for example, 4 mm or less) is formed between it and the surface of the substrate W (step S05). The rotating body 10 rotates at a relatively low predetermined speed (about 50 rpm), causing the substrate W to rotate at a low speed, while the phosphoric acid solution is supplied from the discharge port 42a of the processing liquid holding unit 42 into the gap between the processing liquid holding unit 42 and the surface of the substrate W (step S06). In this way, the phosphoric acid solution supplied between the processing liquid holding unit 42 and the surface of the substrate W is heated to a high temperature by the processing liquid holding unit 42, which is heated by the heater 441.

[0055] In this state, when the phosphoric acid solution is continuously supplied from the discharge port 42a of the processing liquid holding unit 42, the phosphoric acid solution moves sequentially toward the outer periphery of the substrate W, and as the carbonated water on the surface of the substrate W is replaced by phosphoric acid, a portion of the nitride film 103 is etched and removed, as shown in Figure 2(B). After a predetermined processing time has elapsed, the processing liquid holding unit 42 stops supplying the phosphoric acid solution (step S07).

[0056] Next, as shown in Figure 6(B), the processing liquid holding unit 42 rises to a position where a predetermined gap D1 is formed between it and the surface of the substrate W (step S08). Then, the second processing liquid supply unit 50 sprays hydrogen peroxide from the supply nozzle 51 toward the center and outer circumference of the rotating substrate W (step S09). The hydrogen peroxide sprayed toward the center of the substrate W moves sequentially toward the outer circumference of the substrate W, replacing the phosphoric acid solution on the surface of the substrate W with hydrogen peroxide and forming an oxide film 102. In other words, as shown in Figure 2(C), an oxide film 102 is formed in the areas where the oxide film 102 was removed by etching. In addition, an oxide film 102 is formed in areas where the oxide film 102 was not present. After a predetermined processing time has elapsed, the supply nozzle 51 stops supplying hydrogen peroxide (step S10).

[0057] Next, the rotating body 10 rotates at a relatively high predetermined speed (for example, about 200-300 rpm), and the processing liquid holding unit 42 supplies warm pure water to the surface of the substrate W from the discharge port 42a (step S11). As warm pure water is supplied to the surface of the rotating substrate W, the warm pure water moves sequentially toward the outer circumference of the substrate W, thereby replacing the hydrogen peroxide and phosphoric acid on the surface of the substrate W. After a predetermined cleaning time has elapsed, the processing liquid holding unit 42 stops supplying warm pure water (step S12).

[0058] The substrate W stops rotating (step S13), the robot hand 210 is inserted under the substrate W, and as shown in Figure 4(B), the holding part 30 releases the substrate W, and the substrate W is ejected by the robot hand 210 (step S14).

[0059] Subsequently, the transport device 200 carries the etched substrate W to the cleaning device 120, where it performs cleaning by sequentially supplying APM, DIW, and IPA to the rotating substrate W in the chamber 1a (step S15). Furthermore, the transport device 200 unloads the cleaned substrate W from the cleaning device 120 and carries it to the drying device 300. The drying device 300 performs drying by heating the cleaned substrate W while rotating it (step S16).

[0060] [effect] (1) The substrate processing apparatus 1 of this embodiment, as described above, includes a rotating body 10 that holds and rotates a substrate W, a first processing liquid supply unit 40 that performs etching by supplying a first processing liquid for etching to the surface of the substrate W to be processed which is rotated by the rotating body 10, and a second processing liquid supply unit 50 that performs oxide film formation by supplying a second processing liquid for oxidation to the surface of the substrate W to be processed which is rotated by the rotating body 10, in succession to the etching by supplying the first processing liquid.

[0061] In this embodiment, the substrate processing method involves holding and rotating the substrate W with a rotating body 10, supplying a first processing solution for etching to the surface of the substrate W being rotated by the rotating body 10, and supplying a second processing solution for oxide film formation to the surface of the substrate W being rotated by the rotating body 10.

[0062] Therefore, since the oxide film 102 can be formed in areas where it has been removed by etching, or in areas where the oxide film 102 was originally absent, the layer to be protected can be prevented from being exposed. As a result, the layer to be protected is protected by the oxide film 102 during subsequent processing. Consequently, the occurrence of product defects can be reduced.

[0063] (2) This embodiment has a cleaning solution supply unit that supplies a cleaning solution to the surface to be treated in conjunction with the oxide film formation treatment. Since the oxide film formation treatment is performed in conjunction with the etching treatment, even if a cleaning treatment is performed, the oxide film 102 acts as a protective film, protecting the layer to be protected. For example, when cleaning is performed with warm pure water in a common chamber 1a after the etching treatment, the oxide film 102 formed before cleaning prevents the polysilicon 101 from being worn away by the cleaning.

[0064] (3) The apparatus has a chamber 1a (first chamber) that houses the rotating body 10 and in which etching and oxide film formation treatments are performed, and a cleaning device 120 in a separate chamber 1a (second chamber) that cleans the surface to be treated which has an oxide film 102 formed by supplying a second processing liquid. Since the oxide film formation treatment is performed continuously with the etching treatment, even when cleaning is performed by the cleaning device 120, the oxide film 102 acts as a protective film, protecting the layer to be protected. For example, even when the rotating body is removed from the etching device 110 and cleaned in the cleaning device 120 in a separate chamber 1a using an APM or the like, the already formed oxide film 102 prevents the polysilicon 101 from being worn away by the cleaning.

[0065] (4) The first processing liquid supply unit 40 has a discharge port 42a for discharging the first processing liquid onto the substrate W, a heating unit 44 for heating the first processing liquid supplied onto the surface of the substrate W to be processed, and a lifting mechanism 43 for raising and lowering the heating unit 44 relative to the substrate W. The second processing liquid supply unit 50 has a supply nozzle 51 for supplying the second processing liquid toward the center of the surface to be processed. The control unit 60 that controls the first processing liquid supply unit 40 and the second processing liquid supply unit 50 heats the first processing liquid to perform etching by discharging the first processing liquid from the discharge port 42a and bringing the heating unit 44 closer to the substrate W. Following the etching process, the heating unit 44 is moved away and the supply nozzle 51 is discharged with the second processing liquid toward the center of the surface of the substrate W.

[0066] In this way, by supplying a second processing solution toward the center of the rotating substrate W immediately following the etching process using the heated first processing solution, the second processing solution can be efficiently distributed across the entire surface to be processed, enabling high-speed oxide film formation. In this embodiment, a supply nozzle 51 is also provided to supply the second processing solution to the outer periphery of the substrate W. This allows the second processing solution to be supplied to the outer periphery before it reaches the outer periphery from the center, enabling even faster oxide film formation.

[0067] (modified version) (1) A heating unit may be provided to heat the second processing liquid before supplying it to the surface to be processed. For example, the heating unit may be a heater that heats the supply tank or piping of the supply device for the second processing liquid. This makes it possible to speed up the formation rate of the oxide film 102 even if the amount of the second processing liquid supplied is the same. Alternatively, the supply unit that supplies the second processing liquid to the processing liquid supply mechanism 41 may be connected to the processing liquid supply pipe 41c via an individual supply pipe 41b, so that the second processing liquid is supplied from the discharge port 42a of the processing liquid holding unit 42. In this case as well, the heated second processing liquid can be supplied to the substrate W by the heating unit 44. If heating by the heating unit 44 is insufficient, a heating unit may be provided on the supply unit side to preheat it.

[0068] (2) The configuration of the second processing liquid supply unit 50 is not limited to the supply nozzle 51 as described above. The supply nozzle 51 that supplies to the outer circumference of the non-processing surface may be omitted. Alternatively, for example, as shown in Figure 8, a swinging mechanism 54 may be provided that moves a pair of swinging arms 53, each equipped with a supply nozzle 51 at its tip, between a supply position facing the center and the outer circumference of the surface to be processed on the substrate W, and a retracted position that moves away from the supply position to allow loading and unloading of the substrate W. In this case as well, only the swinging arm 53 that supplies the second processing liquid to the center may be provided.

[0069] (3) The processing content and processing solution of the substrate processing apparatus 1 are not limited to those exemplified above. The substrate W and film to be processed are also not limited to those exemplified above.

[0070] [Other embodiments] Although embodiments and modifications of the present invention have been described above, these embodiments and modifications are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments described above can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the invention described in the claims. [Explanation of symbols]

[0071] 1. Substrate processing device 1a Chamber 1b Cassette 1c Transport robot 1d buffer unit 10. Solids of revolution 11 Tables 11a Through hole 11b Outlet 12 bass 13 Fixed base 13a Protective wall 14 cups 20 Rotation mechanism 21 Fixed axis 22 Power source 30 Holding part 31 Rotating Member 32 retaining pins 33 Drive mechanism 40 First processing liquid supply unit 41 Processing liquid supply mechanism 41a Treatment liquid tank 41b Individual conveyance pipe 41c Processing liquid supply pipe 41d Flow control valve 41e flow meter 42 Processing liquid holding section 42a Discharge port 43 Lifting mechanism 44 Heating section 50 Second processing liquid supply unit 51 Supply nozzle 53. Swivel Arm 54. Oscillating mechanism 60 Control Unit 100 silicon wafers 101 Polysilicon 102 Oxide film 103 Nitride film 110 Etching equipment 111 Opposing surfaces 112 Side view 120 Cleaning device 200 Conveyor 210 Robot Hand 220 Transport robots 300 Drying equipment 331 Drive shaft 332 Small gear 333 Large gear 400 Control Unit 411, 412, 413 Supply section 441 Heater 441a Through hole

Claims

1. A rotating body that holds and rotates the substrate, A first processing liquid supply unit performs etching by supplying a first processing liquid for etching to the surface of the substrate to be processed, which is rotated by the aforementioned rotating body, A second processing liquid supply unit performs an oxide film formation treatment by supplying a second processing liquid for oxidation treatment to the surface of the substrate to be treated, which is rotated by the rotating body, in a manner that is continuous with the etching treatment by supplying the first processing liquid. A substrate processing apparatus characterized by having

2. The substrate processing apparatus according to claim 1, characterized in that it has a cleaning liquid supply unit that supplies a cleaning liquid to the surface to be processed, in succession to the oxide film formation process.

3. The rotating body is housed in a first chamber in which the etching process and the oxide film formation process are carried out, The substrate processing apparatus according to claim 1 or 2, further comprising a cleaning device for cleaning the surface to be processed having an oxide film formed by supplying the second processing liquid, in a second chamber separate from the first chamber.

4. The substrate processing apparatus according to any one of claims 1 to 3, characterized in that the first processing solution contains phosphoric acid.

5. The surface of the substrate to be treated includes a nitride film and an oxide film. The substrate processing apparatus according to claim 4, characterized in that the etching process targets the nitride film.

6. The substrate processing apparatus according to any one of claims 1 to 5, characterized in that the second processing solution contains hydrogen peroxide solution or ozonated water.

7. The substrate processing apparatus according to any one of claims 1 to 6, characterized in that it has a heating unit for heating the second processing liquid before supplying it to the surface to be processed.

8. The first processing liquid supply unit is, A discharge port for discharging the processing liquid described above onto the substrate, A heating unit that heats the first processing liquid supplied onto the surface of the substrate to be processed, A lifting mechanism for raising and lowering the heating section relative to the substrate, It has, The second processing liquid supply unit has a supply nozzle that supplies the second processing liquid toward the center of the surface to be processed, The control unit that controls the first processing liquid supply unit and the second processing liquid supply unit, By discharging the first processing liquid from the discharge port and bringing the heating unit closer to the substrate, the first processing liquid is heated to perform the etching process. Following the etching process, the heating unit is separated, and the second processing liquid is discharged from the supply nozzle toward the center of the surface to be processed on the substrate. A substrate processing apparatus according to any one of features 1 to 7.

9. The substrate is held and rotated by a rotating body. Etching is performed by supplying a first processing solution for etching to the surface of the substrate to be processed, which is rotated by the aforementioned rotating body. Following the etching process, a second processing solution for oxide film formation is supplied to the surface of the substrate to be processed, which is rotated by the rotating body. A substrate processing method characterized by the following:

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