Substrate cleaning apparatus and substrate cleaning method

Abstract

The present invention can prevent particles removed from a substrate from reattaching to the substrate. A substrate cleaning apparatus of the present invention includes a substrate holding section that holds a substrate, a gas nozzle that sprays a cleaning gas toward the substrate on the substrate holding section, and a nozzle cover that is provided in a manner of surrounding the gas nozzle. The cleaning gas is sprayed from the gas nozzle into a pressure reduction chamber of the nozzle cover, and a gas cluster that removes particles on the substrate is generated in the pressure reduction chamber. A curtain of gas is sprayed from the gas curtain gas toward the nozzle cover by a holding section support of the substrate holding section, and a curtain of gas is formed between the nozzle cover and the holding section support.

Description

TECHNICAL FIELD

[0001] The present application relates to a substrate cleaning apparatus and a substrate cleaning method. BACKGROUND

[0002] In a semiconductor manufacturing apparatus, the adhesion of particles to a substrate during a manufacturing process is one of the factors that greatly affect the yield of products. For this reason, a substrate is cleaned before or after being processed, but it is desired to develop a cleaning technique that can reliably remove particles in a simple manner while suppressing damage to the substrate. Various cleaning techniques that apply a physical shear force above the adhesion force between particles and a substrate to peel off the particles from the surface of the substrate have been researched and developed, and as one of them, a technique using a physical shear force of a gas cluster can be cited.

[0003] A gas cluster is a block (cluster) in which a plurality of atoms or molecules are gathered by spraying a gas at high pressure into a vacuum formed by a pressure reduction chamber or the like and cooling the gas to a condensation temperature by adiabatic expansion. In substrate cleaning, the gas cluster is irradiated directly or appropriately accelerated to a substrate to remove particles.

[0004] In addition, a technique for effectively removing particles adhering to the inside of a pattern on a substrate has been developed in the related art (see Patent Document 1).

[0005] In such a case, as long as the particles removed from the substrate are prevented from being lifted and adhering to the substrate again, the substrate can be cleaned more effectively.

[0006] RELATED ART DOCUMENTS

[0007] PATENT DOCUMENTS

[0008] Patent Document 1: Japanese Patent Application Publication No. 2013-175681 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] The present application was completed in view of the above, and provides a substrate cleaning apparatus and a substrate cleaning method that can prevent particles removed from a substrate from adhering to the substrate again.

[0011] TECHNICAL SOLUTION TO THE PROBLEM

[0012] The substrate cleaning apparatus of the present application includes a substrate holding section that holds a substrate; a nozzle cover that has a reduced pressure chamber that forms a reduced pressure atmosphere between the substrate and the nozzle cover; and a gas nozzle that injects a cleaning gas having a pressure higher than that of the reduced pressure chamber to generate a gas cluster that cleans the substrate in the reduced pressure chamber. The nozzle cover includes a nozzle cover main body that has the reduced pressure chamber and a peripheral portion that is located at a lower end periphery of the nozzle cover main body, and a gas curtain forming section that forms a gas curtain by injecting a gas for the gas curtain against the peripheral portion is provided on the substrate holding section side.

[0013] Effects of the Invention

[0014] According to the present application, it is possible to prevent particles removed from a substrate from re-attaching to the substrate. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a side view showing a substrate cleaning apparatus of the present embodiment.

[0016] Figure 2 is a side view showing Figure 1 the gas nozzle and the nozzle cover of the substrate cleaning apparatus shown in

[0017] Figure 3 is a side view showing the operation of the substrate cleaning apparatus.

[0018] Figure 4 (a) to (d) of FIG. 8 are side views showing the case where particles are removed using a gas cluster.

[0019] Figure 5 (a) to (d) of FIG. 8 are side views showing the case where particles are removed using a gas cluster.

[0020] Figure 6 is a plan view showing the surface of a wafer.

[0021] Figure 7 is a view showing the entire vacuum processing apparatus in which the substrate cleaning apparatus is assembled.

[0022] Figure 8 is a view showing a modification example of the gas flow path, and is a view corresponding to Figure 2

[0023] Figure 9 is a view showing a modification example of the substrate holding section. DETAILED DESCRIPTION

[0024] [Embodiment]

[0025] First, the entire vacuum processing apparatus in which the substrate cleaning apparatus of the present embodiment is assembled will be described with reference to Figure 7 Figure 7 ​​This is a top view showing the overall structure of the vacuum processing apparatus 101 as a multi-chamber system. In the vacuum processing apparatus 101, for example, three feed outlets 112 are arranged laterally for holding a sealed transport container, FOUP 111, containing 25 semiconductor wafers (hereinafter referred to as "wafers") W as substrates. Furthermore, an atmospheric transport chamber 113 is arranged in a queue along these feed outlets 112, and a gate GT, which can be opened and closed together with the cover of the FOUP 111, is installed on the front wall of the atmospheric transport chamber 113.

[0026] On the opposite side of the inlet / outlet 112 in the atmospheric delivery chamber 113, two loading lock chambers 114 and 115 are airtightly connected. These loading lock chambers 114 and 115 are each equipped with a vacuum pump (not shown) and a leakage valve, configured to switch between atmospheric pressure and vacuum atmospheres. Furthermore, in Figure 7 A gate valve (separation valve) G is provided. Furthermore, a first substrate transport mechanism 116, consisting of a multi-jointed arm for transporting wafers W, is provided within the atmospheric transport chamber 113. Furthermore, viewing the back side from the front side of the atmospheric transport chamber 113, a wafer inspection section 117, serving as a substrate inspection section, is provided on the right side wall of the atmospheric transport chamber 113, and an alignment chamber 118 for adjusting the orientation and eccentricity of the wafers W is provided on the left side wall. The aforementioned first substrate transport mechanism 116 serves to transfer wafers W between the FOUP 111, loading and locking chambers 114 and 115, the wafer inspection section 117, and the alignment chamber 118. Therefore, the first substrate transport mechanism 116 is configured, for example, along the arrangement direction of the FOUP 111 (… Figure 7 (In the X direction) It can be moved, raised and lowered, rotated around the vertical axis, and moved forward and backward.

[0027] When viewed from the atmospheric transport chamber 113, a vacuum transport chamber 102 is hermetically connected to the inner side of the loading and locking chambers 114 and 115. Furthermore, the substrate cleaning apparatus 100 of this embodiment and five vacuum processing modules 121-125 are hermetically connected to the vacuum transport chamber 102. These vacuum processing modules 121-125 are vacuum processing modules that perform CVD (Chemical Vapor Deposition) and sputtering processes on wafers W, for example, those with recesses for forming circuit patterns, i.e., grooves and through-holes for embedding copper wiring, to form films containing copper wiring.

[0028] Further, the vacuum transfer chamber 102 includes a second substrate transfer mechanism 126 for transferring the wafer W under a vacuum atmosphere, and the second substrate transfer mechanism 126 performs the handover of the wafer W to and from the load lock chambers 114, 115, the substrate cleaning apparatus 100, and the vacuum processing modules 121 to 125. The second substrate transfer mechanism 126 includes a multi-joint arm 126a configured to be rotatable about a vertical axis and retractable, and the multi-joint arm 126a is configured to be movable in a longitudinal direction (Y direction) of the substrate cleaning apparatus 100 by a base 126b. Figure 7

[0029] Next, the wafer inspection section 117 will be described. The wafer inspection section 117 is used to acquire particle information including particle sizes of particles adhering to the wafer W. The particle information is, for example, information for ascertaining the positions and sizes of the particles on the wafer W. As the wafer inspection section 117, a device capable of evaluating the particle sizes of the particles on the wafer surface can be used, such as an optical type or an electron beam type surface defect inspection device capable of using regular reflection light or scattered light. Further, a scanning probe microscope such as a scanning electron microscope (SEM), a scanning tunneling microscope (STM), or an atomic force microscope (AFM) can be used.

[0030] Next, the substrate cleaning apparatus 100 according to the present embodiment will be described. The substrate cleaning apparatus 100 is used to house the wafer W inside and perform a removal process of adhering matter.

[0031] As shown in FIG. 1, the substrate cleaning apparatus 100 includes a cleaning processing chamber 31, a substrate holding section 11 disposed inside the cleaning processing chamber 31 to rotatably hold a wafer W disposed in a horizontal direction, a gas nozzle 50 to spray a cleaning gas to the wafer W on the substrate holding section 11, and a nozzle cover 20 disposed so as to surround the gas nozzle 50, having a reduced pressure chamber 20A to form a reduced pressure atmosphere between the wafer W. Figures 1 to 3

[0032] The cleaning processing chamber 31 is formed to be a positive pressure with respect to the outside, and a clean gas supply section 40 to supply a clean gas is provided at an upper portion inside the cleaning processing chamber 31, and the clean gas supply section 40 is connected to a gas supply source 42 via a gas supply passage 41.

[0033] Further, an exhaust mechanism 44 such as an exhaust fan is connected to a lower portion inside the cleaning processing chamber 31 via an exhaust passage 43. Further, an opening 34 for feeding in or out the wafer W is formed in a side wall of the cleaning processing chamber 31, and the opening 34 is closably sealed by a door 35.

[0034] ​​Further, the substrate holding portion 11 has a holding portion main body 11A that holds the wafer W arranged in the horizontal direction, and a holding portion support member 12 that is provided to the outer periphery of the holding portion main body 11A, surrounds the outer periphery of the wafer W from the side, and the holding portion main body 11A and the holding portion support member 12 are integrally rotatable by a drive shaft 13 driven by a drive motor 14.

[0035] Further, the gas nozzle 50 jets carbon dioxide (CO2) gas and helium (He) gas toward the wafer W as described later, and a nozzle cover 20 is provided in a manner of surrounding the gas nozzle 50.

[0036] Specifically, as shown in Figures 1 to 3 the nozzle cover 20 has an overturned cup shape, includes a nozzle cover main body 21 that has a decompression chamber 20A inside, and a peripheral edge portion 22 that extends to the lower end periphery of the nozzle cover main body 21, and the gas nozzle 50 is attached to the nozzle cover main body 21 of the cup shape in a manner of penetrating the center thereof.

[0037] The nozzle cover main body 21 and the peripheral edge portion 22 of the nozzle cover 20 are integrally formed, and the entire body is made of ceramic.

[0038] Further, the nozzle cover 20 including the nozzle cover main body 21 and the peripheral edge portion 22 is provided in a manner of covering the entire area of the wafer W.

[0039] In particular, as described later, the nozzle cover 20 is movable with respect to the wafer W by the moving arm 17, and during this time, the decompression chamber 20A of the nozzle cover 20 moves from the center of the wafer W to the periphery of the wafer W. In this case, the nozzle cover 20 is always able to cover the entire area of the wafer W during the time when the decompression chamber 20A moves from the center of the wafer W to the periphery of the wafer W. Thus, the particles that are discharged from the wafer W and are cleaned off are prevented from flying to the outside of the nozzle cover 20.

[0040] Further, the end portion 12A of the holding portion support member 12 on the nozzle cover 20 side in the substrate holding portion 11 has a jet hole that jets the gas curtain gas such as N2 gas or air supplied from the gas flow path 15 described later toward the nozzle cover 20 side. For example, by using a porous material for the holding portion support member 12 of the substrate holding portion 11, the end portion 12A of the holding portion support member 12 on the nozzle cover 20 side is provided with a plurality of holes, and the holes function as the jet hole that jets the gas curtain gas toward the nozzle cover 20 side. Thus, the holes of the end portion 12A of the holding portion support member 12 on the nozzle cover 20 side function as a gas curtain forming portion that forms a gas curtain between the holding portion support member 12 and the nozzle cover 20.

[0041] Further, the gas curtain gas including N2 gas or air is supplied to the holding portion support member 12 by the gas flow path 15 connected to the gas curtain gas supply source 16. The gas flow path 15 is provided in a manner of penetrating the holding portion support member 12, and the gas curtain gas is supplied to the holding portion support member 12 from the gas flow path 15. Figure 2As shown, the drive shaft 13 can be directly configured to the retaining support 12, or as... Figure 8 As shown, it is configured as a drive shaft 13 formed by a hollow space and a substrate holding part 11.

[0042] Furthermore, a pressure-reducing unit 24 is provided adjacent to the gas nozzle 50 in the nozzle cover body 21 of the nozzle cover 20 to generate a pressure-reducing atmosphere within the pressure-reducing chamber 20A of the nozzle cover 20. This pressure-reducing unit 24 is connected to the pressure-reducing pump 27 via a connecting line 28. In this case, the connecting line 28 extends through the wall of the cleaning chamber 31 and reaches the pressure-reducing pump 27 located outside the cleaning chamber 31.

[0043] Furthermore, the gas nozzle 50 is held by the nozzle cover body 21 of the nozzle cover 20, and the gas nozzle 50 and the nozzle cover 20 together can move horizontally within the cleaning chamber 31 using a movable arm 17 disposed within the cleaning chamber 31. In this embodiment, using the movable arm 17, the gas nozzle 50 and the nozzle cover 20 can move on the wafer W held by the substrate holding portion 11 from the center of the wafer W to the periphery, or from the periphery of the wafer W to the center.

[0044] In addition, the diameter of the outlet 50a side of the gas nozzle 50 is enlarged, the outer diameter L1 of the front end of the outlet 50a is, for example, 10 mm, and the outer diameter L2 of the end of the pressure reducing chamber 20A of the nozzle cover 20 on the wafer W side is, for example, 50 to 60 mm.

[0045] like Figures 1 to 3 As shown, the substrate holding portion 11 holding the wafer W has a holding portion body 11A and a holding portion support member 12 disposed on the outer periphery of the holding portion body 11A and surrounding the outer periphery of the wafer W from the side. The holding portion body 11A is made of SUS, aluminum, or ceramic and has a high coefficient of friction on its surface. Therefore, by simply placing the wafer W on the holding portion body 11A, the wafer W can be stably held on the holding portion body 11A without the need for an adsorption mechanism.

[0046] Furthermore, the retaining support member 12 is made of a porous material such as ceramic, and its upper surface is preferably on the same surface as the upper surface of the retaining body 11A. In this case, the porous material such as ceramic is exposed only in the portion of the retaining support member 12 opposite to the peripheral portion 22 of the nozzle cover 20, while the other portions of the retaining body 11A are coated or non-porous materials are attached to them. Gas for the air curtain is supplied from the portion opposite to the peripheral portion 22. Alternatively, the retaining support member 12 can be made of SUS material or aluminum material other than ceramic, and it can be obtained by machining these ceramic, SUS, or aluminum materials.

[0047] In addition, such asFigure 1 As shown, the gas nozzle 50 is connected to one end side of a connection line 50A extending through the wall surface of the cleaning treatment chamber 31. The connection line 50A has a flexible configuration inside the cleaning treatment chamber 31, and is able to follow the movement of the gas nozzle 50. Further, the connection line 50A is connected to a supply passage 52 of carbon dioxide (CO2) gas and a supply passage 53 of helium (He) gas outside the cleaning treatment chamber 31 via a pressure regulating valve 51 constituting a pressure regulating section. The supply passage 52 has an on-off valve VI, a carbon dioxide gas flow rate regulating section 52a, and a supply source 52b of carbon dioxide gas, and the supply passage 53 has an on-off valve V2, a helium gas flow rate regulating section 53a, and a supply source 53b of helium gas.

[0048] The carbon dioxide gas is a gas for cleaning (cleaning gas), and a gas cluster is formed using this gas. Further, the helium gas is a gas for pushing (pushing gas). Helium gas is difficult to form a cluster, and when helium gas is mixed in the carbon dioxide gas, it has the effect of increasing the speed of the cluster generated by the carbon dioxide gas. Further, a pressure detecting section 54 that detects the pressure inside the connection line 50A is provided in the connection line 50A, and based on the detected value of this pressure detecting section 54, the opening degree of the pressure regulating valve 51 is regulated using a control section 55 described later, and the gas pressure inside the pressure reducing chamber 20A is controlled.

[0049] In addition, the control section 55 can control the carbon dioxide gas flow rate regulating section 52a and the helium gas flow rate regulating section 53a to regulate the gas flow rate based on the detected value of the pressure detecting section 54 described above. Furthermore, a pressure increasing mechanism such as a gas booster or the like can be used to increase the supply pressure between the on-off valves VI, V2 of each gas and the pressure regulating valve 51, and the pressure regulating valve 51 can be used to regulate the pressure.

[0050] In addition, in the vacuum processing device 101, as shown in Figure 1 and Figure 3 a control section 55 constituted by, for example, a computer for controlling the operation of the entire device is provided. The control section 55 includes a CPU, a program, and a storage section. The above-mentioned program is programmed with a step group so as to perform the operation of the device corresponding to the vacuum processing performed by the vacuum processing modules 121 to 125 in addition to performing the cleaning processing described later. The program is stored in a storage medium such as a hard disk, an optical disk, a magneto-optical disk, a memory card, a floppy disk, or the like, and is installed in the control section 55 from the storage medium.

[0051] Furthermore, the storage unit of the control unit 55 stores particle information acquired by the wafer inspection unit 117. This particle information refers to information that associates the position of the wafer W with the size of the particles. The particle size is, for example, a value allocated according to the particle diameter range set by the wafer inspection unit 117, such as a value defined as 20nm or more and less than 40nm, or 40nm or more and less than 60nm.

[0052] The function of this embodiment, configured as described below, will be explained.

[0053] When FOUP111 is loaded Figure 7 When the wafer is fed into the inlet / outlet 112, the wafer W is removed from the FOUP 111 by the first substrate transport mechanism 116. The wafer W has recesses (grooves and vias) formed for embedding copper wiring as pattern recesses. Next, the wafer W is transported to the alignment chamber 118 via an atmospheric transport chamber 113 under normal pressure for alignment. Afterwards, the wafer W is transported by the first substrate transport mechanism 116 to the wafer inspection unit 117, where particle information is acquired. The acquired particle information is sent to the control unit 55.

[0054] The wafer W, inspected by the wafer inspection unit 117, is fed by the first substrate transport mechanism 116 into the loading and locking chambers 114 and 115, which are set to atmospheric pressure. After the atmosphere in the loading and locking chambers 114 and 115 is switched to a vacuum atmosphere, it is transported by the second substrate transport mechanism 126 to the substrate cleaning device 100 for particle removal.

[0055] like Figures 1 to 3 As shown, in the substrate cleaning apparatus 100, firstly, from the end of the holding support 12 of the substrate holding portion 11 on the nozzle cover 20 side, a curtain gas such as N2 gas or air supplied via the gas flow path 15 (see reference) is sprayed onto the nozzle cover 20. Figure 1 The air curtain gas injected into the nozzle cover 20 forms an air curtain 12B between the retaining support 12 and the peripheral portion 22 of the nozzle cover 20, sealing the inside and outside of the pressure reducing chamber 20A of the nozzle cover 20.

[0056] During this period, the pressure reducing pump 27 operates, and the pressure reducing unit 24 reduces the pressure inside the pressure reducing chamber 20A of the nozzle cover 20. The pressure inside the pressure reducing chamber 20A is reduced compared to the outside of the nozzle cover 20.

[0057] Subsequently, carbon dioxide gas is supplied from the gas nozzle 50 to the pressure reduction chamber 20A of the nozzle cover 20 as a cleaning gas, and helium gas is supplied to the pressure reduction chamber 20A of the nozzle cover 20 as a pushing gas.

[0058] In this case, by ejecting carbon dioxide gas as a cleaning gas from the outlet 50a of the gas nozzle 50 into the reduced-pressure chamber 20A, a gas cluster can be generated in the reduced-pressure chamber 20A, and the gas cluster can be used to remove the particles 1 present on the wafer W (refer to Figure 6 ).

[0059] In the present embodiment, the amount of gas ejected as the gas curtain from the end portion of the nozzle cover 20 side of the holding portion support 12 is greater than the amount of exhaust M2 discharged from the reduced-pressure chamber 20A via the reduced-pressure generating portion 24, and is, for example, an amount of ejection of M1 = 10 to 30 L / min, and an amount of exhaust of M2 = M1 x 1 to 2 times.

[0060] Here, the principle of removing particles from the surface of the wafer W using a gas cluster will be described. A gas cluster refers to a substance generated by supplying a gas from a region having a higher pressure than the reduced-pressure chamber 20A of the nozzle cover 20 to a processing atmosphere, cooling to the condensation temperature of the gas by adiabatic expansion, and thereby gathering atoms or molecules of the gas as an aggregate. For example, the processing pressure in the reduced-pressure chamber 20A of the nozzle cover 20 is set to a vacuum atmosphere of, for example, 0.1 to 100 Pa, and the gas nozzle 50 is supplied with a cleaning gas (carbon dioxide gas) at a pressure of, for example, 0.3 to 5.0 MPa. This cleaning gas is cooled to below the condensation temperature due to the sharp adiabatic expansion when supplied to the processing atmosphere of the reduced-pressure chamber 20A of the nozzle cover 20, and thus, as shown in Figs. 2 Figure 2 and Figure 3 , each molecule 2a is bonded to each other on the outlet 50a side of the gas nozzle 50 by Van der Waals forces to become a gas cluster 2 as an aggregate. The gas cluster 2 is neutral in the present example. For example, with respect to a gas cluster, 5 x 10 3 atoms (molecules) per cluster are about 8 nm, and thus, 5 x 10 3 atoms (molecules) per cluster or more is preferable.

[0061] The gas cluster 2 generated on the outlet 50a side of the gas nozzle 50 is irradiated vertically to the wafer W. Then, the gas cluster 2 enters a recess for a circuit pattern of the wafer W, and blows away the particles 1 in the recess to remove them.

[0062] Figure 4 Figs. 2 Figure 5 (a) to (d) schematically show a case where the particles 1 on the wafer W are removed by the gas cluster 2. Figure 4 Figs. 3 Figure 4 (a) to (d) are diagrams showing a case where the gas cluster 2 collides with the particles 1 on the wafer W. In this case, the gas cluster 2 is irradiated vertically to the surface of the wafer W as shown in Fig. 3 Figure 4When the gas cluster 2 in the state of offset (a state in which the center of the gas cluster 2 is misaligned with the center of the particle 1 when viewed from above) shown in (b) collides with the particle 1, as shown in (c) of FIG. 6, the impact at the time of collision of the gas cluster 2 exerts a force to move the particle 1 laterally. As a result, the particle 1 is peeled off from the wafer W surface, floats, and flies sideways or diagonally upward. Figure 4

[0063] In addition, the gas cluster 2 does not collide directly with the particle 1, but, as shown in (a) of FIG. 7, by irradiating in the vicinity of the particle 1, it is also possible to remove the particle 1. When the gas cluster 2 collides with the wafer W, the constituent molecules of the gas cluster 2 gradually decompose while diffusing laterally (refer to (b) of FIG. 7). At this time, the high kinetic energy density region moves in the lateral (horizontal) direction, and thus the particle 1 is peeled off from the wafer W and blown away (refer to (c) and (d) of FIG. 7). In this way, the particle 1 flies out of the recess and scatters into the reduced-pressure chamber 20A of the nozzle cover 20, and is removed to the outside via the reduced-pressure generating section 24 from the reduced-pressure pump 27 provided outside the cleaning treatment chamber 31. Figure 5 Figure 5 Figure 5

[0064] As described above, during the period in which the gas cluster 2 is generated by spraying the carbon dioxide gas and the helium gas from the gas nozzle 50 toward the wafer W, and the particle 1 on the wafer W is removed using the gas cluster, the wafer W is rotated by rotating the substrate holding section 11, and the gas nozzle 50 and the nozzle cover 20 are moved from the center of the wafer W to the periphery of the wafer W by the moving arm 17. Thereby, it is possible to effectively remove the particle 1 on the wafer W using the gas cluster 2 over the entire area of the wafer W.

[0065] During this period, when the gas nozzle 50 is between the center of the wafer W and the periphery of the wafer W (refer to FIGS. 8 and 9), the gas curtain gas sprayed from the nozzle cover 20 side end portion of the holding section support 12 goes to the nozzle cover, and a gas curtain 12B is formed in the gap G (for example, 0.85 mm) between the holding section support 12 and the nozzle cover 20, and the reduced-pressure chamber 20A of the nozzle cover 20 is maintained in a sealed state. Figure 1 Figure 2 Next, when the gas nozzle 50 reaches the periphery of the wafer W (refer to FIGS. 10 and 11), a part of the gas curtain gas sprayed from the nozzle cover 20 side end portion of the holding section support 12 is sprayed to the nozzle cover 20, and the remaining part also enters the reduced-pressure chamber 20A. However, the flow rate of the gas curtain gas that enters the reduced-pressure chamber 20A is small, and does not affect the reduced-pressure atmosphere of the reduced-pressure chamber 20A.

[0066] Figure 3

[0067] ​​​​​​​In this case, the gas curtain gas ejected from the nozzle cover 20 side end portion of the holding portion support 12 forms a gas curtain 12B in the gap G between the nozzle cover 20 side end portion of the holding portion support 12 and the nozzle cover 20, and the inside of the pressure reducing chamber 20A of the nozzle cover 20 is maintained in a sealed state.

[0068] In the present embodiment, the holding portion support 12 is fixed to the holding portion main body 11A by a fixing screw not shown, and the height position of the holding portion support 12 can be adjusted according to the thickness of the wafer W. In the present embodiment, the height position of the holding portion support 12 is adjusted so that the upper surface of the wafer W on the holding portion main body 11A is located on the same plane as the upper surface of the holding portion support 12, and the height of the upper surface of the wafer W coincides with the upper surface of the holding portion support 12. Figure 3

[0069] Therefore, the gap G between the nozzle cover 20 side end portion of the holding portion support 12 and the nozzle cover 20, and the gap between the wafer W and the nozzle cover 20 are coincident.

[0070] As described above, according to the present embodiment, the wafer W is rotated by the substrate holding portion 11, and the gas nozzle 50 and the nozzle cover 20 are moved from the center to the periphery of the wafer W by the moving arm 17, whereby the particles 1 on the wafer W can be removed using the gas cluster 2 over the entire area of the wafer W. Further, by fixing the gas nozzle 50 and the nozzle cover 20 at the periphery of the wafer W, rotating the wafer W by the substrate holding portion 11, the particles 1 located at the periphery of the wafer W can be removed using the gas cluster 2.

[0071] Further, the carbon dioxide gas and the helium gas are supplied from the gas nozzle 50 into the pressure reducing chamber 20A of the nozzle cover 20 to generate the gas cluster 2, the particles 1 on the wafer W are removed using the gas cluster 2, and the removed particles 1 are discharged from the pressure reducing chamber 20A to the outside. Therefore, the particles 1 removed from the wafer W are not lifted to be attached again to other portions of the wafer W, and the wafer W as a whole can be kept clean.

[0072] In particular, the nozzle cover 20 is movable with respect to the wafer W by the moving arm 17, and the pressure reducing chamber 20A of the nozzle cover 20 is moved from the center of the wafer W to the periphery of the wafer W when the particles 1 on the wafer W are removed using the gas cluster 2. In this case, the entire area of the wafer W is always covered by the nozzle cover 20 during the movement of the pressure reducing chamber 20A from the center of the wafer W to the periphery of the wafer W, and the particles 1 discharged from the wafer W by cleaning are prevented from flying to the outside of the nozzle cover 20, and therefore the lifted particles 1 can be reliably prevented from being attached again to the wafer W.

[0073] ​Furthermore, in the above embodiments, an example was shown where carbon dioxide gas was used as the cleaning gas and helium gas was used as the pushing gas, but this is not a limitation; argon gas or the like could also be used as the cleaning gas and hydrogen gas or the like as the pushing gas. When using a combination of carbon dioxide gas and hydrogen gas, a high cleaning effect can be obtained with relatively inexpensive gases.

[0074] In addition, an example of spraying a curtain gas such as N2 gas or air onto the wafer W from the end 21A of the nozzle cover 20 on the wafer W side is shown, but it is not limited to this, and other gases that do not affect the generation of gas clusters may also be used.

[0075] Furthermore, in the above embodiment, an example is shown where the gas nozzle 50 and nozzle cover 20 move on the wafer W held by the substrate holding portion 11 using the moving arm 17. However, the gas nozzle 50 and nozzle cover 20 can be structures that are capable of relative movement on the wafer W. For example, such as Figure 9 As shown, a drive mechanism 60 with a drive section 60a and a drive arm 60b can also be provided, and the substrate holding section 11 is connected to the drive arm 60b. In this case, while the substrate holding section 11 is rotated by the drive motor 14, causing the wafer W held in the substrate holding section 11 to rotate, the substrate holding section 11 is moved in the horizontal direction by the drive mechanism 60, thereby cleaning the entire surface of the wafer W even without moving the gas nozzle 50 and the nozzle cover 20.

[0076] Explanation of reference numerals in the attached figures

[0077] 1 particle

[0078] 2 Gas Clusters

[0079] 11 Substrate Holding Section

[0080] 11A Main Body

[0081] 12 Retaining Support Components

[0082] 13 drive shafts

[0083] 14 drive motors

[0084] 15 Gas Flow Path

[0085] 16. Gas supply source for air curtain

[0086] 20 gas shields

[0087] 21 Gas Shield Main Body

[0088] 22 Peripheral

[0089] 24 Decompression Generation Section

[0090] 27 Pressure Reducing Pump

[0091] 28 connecting line

[0092] 31 cleaning chamber

[0093] 40 clean gas supply section

[0094] 41 gas supply passage

[0095] 42 gas supply source

[0096] 43 exhaust passage

[0097] 44 exhaust mechanism

[0098] 50 gas nozzle

[0099] 60 drive mechanism

[0100] 100 substrate cleaning apparatus

Claims

1. A substrate cleaning apparatus, characterized by comprising: comprises: a substrate holding section that holds a substrate; a nozzle cover having a decompression chamber that forms a decompression atmosphere between the substrate and the nozzle cover; and a gas nozzle that ejects a cleaning gas at a high pressure higher than the pressure of the decompression chamber to generate a gas cluster that cleans the substrate in the decompression chamber and is relatively movable in a horizontal direction with respect to the substrate holding section, the nozzle cover includes a nozzle cover main body having the decompression chamber and a peripheral portion located at the lower end periphery of the nozzle cover main body, the nozzle cover covers the entire area of the substrate during a period in which the decompression chamber moves from the center to the periphery of the substrate while removing particles on the substrate using the gas cluster, thereby preventing the particles discharged from the substrate from flying out to the outside of the nozzle cover, a gas curtain forming section that forms a gas curtain by ejecting a gas for the gas curtain toward the peripheral portion is provided on the substrate holding section side.

2. The substrate cleaning apparatus according to claim 1, wherein: the substrate holding section has a holding section main body that holds the substrate and a holding section support member that is provided at the outer periphery of the holding section main body and surrounds the outer periphery of the substrate, the gas curtain forming section is provided at the holding section support member, and a gas flow path that communicates with the gas curtain forming section and supplies the gas curtain gas to the gas curtain forming section side is connected to the holding section support member.

3. The substrate cleaning apparatus according to claim 2, wherein: the holding section support member is composed of a porous material.

4. The substrate cleaning apparatus according to claim 2, wherein: the upper surface of the substrate on the holding section main body and the upper surface of the holding section support member are on the same plane.

5. The substrate cleaning apparatus according to any one of claims 1, 3, and 4, wherein: a decompression generating section that makes the decompression chamber inside the nozzle cover into a decompression atmosphere is provided at the nozzle cover.

6. The substrate cleaning apparatus according to any one of claims 1, 3, and 4, wherein: the substrate holding section is rotatable, and the gas nozzle and the substrate holding section are relatively movable in a horizontal direction.

7. A substrate cleaning method, comprising: using a substrate cleaning apparatus, the substrate cleaning apparatus includes a substrate holding section that holds a substrate, a nozzle cover having a decompression chamber that forms a decompression atmosphere between the substrate and the nozzle cover, and a gas nozzle that is relatively movable in a horizontal direction with respect to the substrate holding section, the nozzle cover includes a nozzle cover main body having the decompression chamber and a peripheral portion located at the lower end periphery of the nozzle cover main body, the substrate cleaning method includes: a step of forming a gas curtain by ejecting a gas for the gas curtain toward the peripheral portion from a gas curtain forming section provided at the substrate holding section; and a step of ejecting a cleaning gas at a high pressure higher than the pressure of the decompression chamber from the gas nozzle to generate a gas cluster that cleans the substrate in the decompression chamber. The nozzle cover covers the entire area of the substrate during the movement of the reduced pressure chamber from the center to the periphery of the substrate while the gas clusters are used to remove particles on the substrate on one side, thereby preventing the particles discharged from the substrate being cleaned from flying to the outside of the nozzle cover.

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