JP4592643B2 - Substrate processing equipment - Google Patents

Description

  The present invention relates to a substrate processing apparatus for processing a substrate by supplying a processing liquid to the substrate.

  Conventionally, in a manufacturing process of a semiconductor substrate (hereinafter simply referred to as “substrate”), various processes are performed by supplying a processing liquid to the substrate. For example, in the substrate cleaning process, particles attached to the surface of the substrate are removed by spraying a cleaning liquid such as pure water onto the substrate.

  By the way, in such a cleaning process, it is known that the entire surface of the substrate is charged by contact between the substrate having an insulating film formed on the surface and pure water having a high specific resistance. For example, the substrate is negatively charged when an oxide film is formed on the substrate surface, and positively charged when a resist film is formed on the substrate surface. Here, if the charge amount of the substrate becomes large, there is a risk of damage of the wiring due to reattachment of particles or discharge during or after cleaning. Thus, various techniques for suppressing the charging of the substrate have been proposed for the substrate processing apparatus.

  For example, in Patent Document 1, in a cleaning apparatus that supplies a cleaning liquid to a rotating substrate and performs cleaning, cleaning is performed while ionized nitrogen gas is purged into a processing space on the substrate, thereby suppressing charging of the substrate surface. Techniques to do this are disclosed. Further, in Patent Document 2, in a cleaning apparatus that immerses and cleans a substrate in a processing tank in which a cleaning liquid is stored, a liquid that is sprayed onto the substrate when the cleaning liquid is replaced is obtained from pure water by dissolving carbon dioxide gas in pure water. Also disclosed is a technique for suppressing the charging of the substrate surface by using carbon dioxide-dissolved water with reduced specific resistance.

  In Patent Document 3, pure water is ejected from a nozzle at a high speed to generate fine droplets of pure water charged by fluid friction with the nozzle, and the droplets are brought into contact with the charged substance. A static eliminator that removes static electricity is disclosed, and a charged semiconductor substrate after cleaning is cited as an application target of the static eliminator.

On the other hand, Non-Patent Document 1 describes an experiment relating to a mechanism for generating a charged mist generated when a jet of pure water ejected from a nozzle collides with a silicon wafer. In the apparatus used for the experiment, the charge amount of the charged fog is changed by controlling the charge amount of the jet by arranging the induction electrode in the pure water ejection path.
JP 2002-184660 A JP 2005-183791 A Japanese Patent Laid-Open No. 10-149893 Kazuaki Asano, Hirofumi Shimokawa, “Charged fog due to collision between water jet and silicon wafer”, Proceedings of the Electrostatic Society of Japan '00 (2000.3), Electrostatic Society, March 2000, p. 25-26

  By the way, in the cleaning process in the ionized gas atmosphere as in Patent Document 1, it is difficult to continuously and efficiently supply the ionized gas to the substrate surface, and there is a limit to the suppression of charging of the substrate. On the other hand, in the apparatuses of Patent Document 2 and Patent Document 3, charging of the substrate during the cleaning process cannot be suppressed.

  The present invention has been made in view of the above problems, and efficiently induces a charge having a polarity opposite to the substrate potential after processing to the processing liquid discharged from the discharge unit, and supplies the processing liquid to the substrate to thereby provide a substrate. It is an object to efficiently suppress charging of the substrate during the processing.

  The invention according to claim 1 is a substrate processing apparatus for processing a substrate by supplying a processing liquid to the substrate, wherein the discharging unit discharges the processing liquid toward the main surface of the substrate, and the discharging unit A treatment liquid supply section for guiding a treatment liquid; and disposed between the discharge section and the main surface of the substrate in the vicinity of the discharge port of the discharge section while being electrically insulated from the discharge section, An induction electrode that induces electric charge in the treatment liquid in the vicinity of the discharge port by applying a potential difference between the conductive liquid contact part of the treatment liquid supply unit and the induction electrode of the discharge part. An inclined surface that surrounds the periphery of the discharge port and is inclined with respect to the central axis of the discharge port, and in an arbitrary cross section of the inclined surface by a surface including the central axis, the direction related to a direction perpendicular to the central axis The distance between the central axis and the inclined surface is At between the discharge portion and the main surface of the substrate closer to the discharge port is longer.

  The invention according to claim 2 is the substrate processing apparatus according to claim 1, wherein the inclined surface of the induction electrode is an annular shape surrounding the central axis of the discharge port, and the central axis is the center. It is a rotating surface.

  A third aspect of the present invention is the substrate processing apparatus according to the second aspect, wherein the inclined surface of the induction electrode is a part of a spherical surface centered on the center of the discharge port.

  The invention according to claim 4 is the substrate processing apparatus according to claim 2, wherein the inclined surface of the induction electrode is a part of a conical surface having an apex on the central axis of the discharge port. .

  According to a fifth aspect of the present invention, in the substrate processing apparatus according to the fourth aspect, an angle formed between the generatrix of the conical surface and the central axis is 45 °.

  A sixth aspect of the present invention is the substrate processing apparatus according to any one of the first to fifth aspects, wherein the position of the outer edge of the inclined surface in the central axis direction is the central axis of the discharge port. Match the position in the direction.

  A seventh aspect of the present invention is the substrate processing apparatus according to any one of the first to sixth aspects, wherein the discharge section ejects droplets of the processing liquid toward the substrate.

  The invention according to claim 8 is the substrate processing apparatus according to claim 7, wherein the discharge unit mixes the processing liquid and a carrier gas in the discharge unit or in the vicinity of the discharge port. To produce the droplets of the treatment liquid.

A ninth aspect of the present invention is the substrate processing apparatus according to any one of the first to eighth aspects, wherein the specific resistance of the processing liquid is 1 × 10 ² Ωm or more.

  A tenth aspect of the present invention is the substrate processing apparatus according to the ninth aspect, wherein the processing liquid is pure water.

  The invention according to claim 11 is the substrate processing apparatus according to claim 9, wherein the processing liquid is carbon dioxide-dissolved water obtained by dissolving carbon dioxide in pure water.

  In the present invention, it is possible to efficiently induce charge in the processing liquid and efficiently suppress charging of the substrate. In the second and third aspects of the invention, electric charges can be induced approximately evenly in the vicinity of the discharge port. In the inventions of claims 4 and 5, the inclined surface can be easily formed.

FIG. 1 is a diagram showing a configuration of a substrate processing apparatus 1 according to a first embodiment of the present invention. The substrate processing apparatus 1 supplies particles with a cleaning liquid to a semiconductor substrate 9 (hereinafter simply referred to as “substrate 9”) having an insulating film formed on the surface thereof to perform cleaning processing. The substrate cleaning apparatus removes the foreign matter. In the present embodiment, pure water having a specific resistance of about 1.8 × 10 ⁵ Ωm is used as the cleaning liquid. In the present embodiment, the substrate 9 having an oxide film formed on the surface is cleaned.

  As shown in FIG. 1, the substrate processing apparatus 1 is disposed above the substrate holding unit 2 that holds the substrate 9 from the lower side and the main surface on the upper side of the substrate 9 (hereinafter referred to as “upper surface”). The discharge unit 3 that discharges the cleaning liquid toward the surface, the circular cleaning liquid supply unit (that is, the processing liquid supply unit) 41 that guides the cleaning liquid to the discharge unit 3, and the cleaning liquid supply unit 41 lead the carrier gas to the discharge unit 3 separately. An induction electrode 6 that is fixed to the discharge unit 3 via a gas supply unit 42 and a non-conductive support member 35 and is disposed between the discharge unit 3 and the substrate 9 in the vicinity of the discharge port 31 of the discharge unit 3; In addition, a discharge unit moving mechanism 5 that moves the discharge unit 3 relative to the substrate 9 in parallel with the upper surface of the substrate 9 together with the induction electrode 6 is provided. In FIG. 1, for convenience of illustration, a part of the induction electrode 6 and the substrate holding part 2 is drawn in a cross section (the same applies to FIG. 7).

  The substrate holding unit 2 includes a chuck 21 that holds the substantially disk-shaped substrate 9 from the lower side and the outer peripheral side, a rotating mechanism 22 that rotates the substrate 9 together with the chuck 21, and a processing cup 23 that covers the outer periphery of the chuck 21. . The rotation mechanism 22 includes a shaft 221 connected to the lower side of the chuck 21 and a motor 222 that rotates the shaft 221, and the substrate 9 rotates together with the shaft 221 and the chuck 21 by driving the motor 222. The processing cup 23 is disposed on the outer periphery of the chuck 21 to prevent the cleaning liquid supplied on the substrate 9 from scattering to the periphery, and the processing cup 23 is provided below the processing cup 23 and supplied to the substrate 9. A discharge port 232 for discharging the cleaning liquid is provided.

  The discharge unit moving mechanism 5 includes an arm 51 having the discharge unit 3 fixed at the tip, and a motor 52 that swings the arm 51. In the substrate processing apparatus 1, when the motor 52 is driven, the discharge unit 3 reciprocates in a circular arc shape that is close to a straight line parallel to the upper surface of the substrate 9 together with the arm 51.

FIG. 2 is a longitudinal sectional view showing the vicinity of the discharge unit 3. In FIG. 2, illustration of the support member 35 is omitted for the sake of illustration (the same applies to FIG. 5). As shown in FIG. 2, the discharge unit 3 is an internal mixing type two-fluid nozzle, and includes a circular cleaning liquid pipe 32 centered on the central axis 30 of the discharge unit 3 (also the central axis of the discharge port 31). Prepare inside. The cleaning liquid pipe 32 is connected to the cleaning liquid supply section 41 at the upper part of the discharge section 3, and the space inside the cleaning liquid pipe 32 becomes a cleaning liquid flow path 321 through which the cleaning liquid supplied from the cleaning liquid supply section 41 flows. A space between the outer wall 34 of the discharge unit 3 and the cleaning liquid pipe 32 is a carrier gas (for example, nitrogen (N ₂ ) gas or air) supplied from the gas supply unit 42, and in this embodiment, nitrogen gas ) Flows, and the gas flow path 33 surrounds the cleaning liquid flow path 321.

  In the discharge unit 3, the tip of the cleaning liquid pipe 32 is located inside the discharge port 31 (that is, the upper side in FIG. 2), and the cleaning liquid ejected from the cleaning liquid pipe 32 is separated from the carrier gas in the discharge part 3. By mixing, minute droplets of the cleaning liquid are generated and ejected together with the carrier gas from the discharge port 31 toward the substrate 9 (see FIG. 1). The inner diameter of the discharge port 31 is about 2 to 3 mm.

  The cleaning liquid pipe 32 (that is, the part forming the cleaning liquid flow path 321 in the discharging section 3) and the cleaning liquid supply section 41 connected to the cleaning liquid pipe 32 are both conductive carbon (preferably amorphous carbon). Or glassy carbon such as glassy carbon) or a conductive resin (for example, conductive PEEK (polyether ether ketone) or conductive PTFE (polytetrafluoroethylene)). In the present embodiment, the cleaning liquid pipe 32 and the cleaning liquid supply unit 41 are formed of glassy conductive carbon. Glassy carbon is a hard carbon material having a homogeneous and dense structure, and is excellent in electrical conductivity, chemical resistance, heat resistance, and the like.

  In the substrate processing apparatus 1, the cleaning liquid pipe 32 and the cleaning liquid supply unit 41 are one cleaning liquid supply pipe that supplies the cleaning liquid to the substrate 9, and the entire cleaning liquid supply pipe is a conductive liquid contact part that contacts the cleaning liquid. . In the substrate processing apparatus 1, a conductive wire 82 is connected to a portion near the tip of the cleaning liquid pipe 32, and as shown in FIG. 1, the cleaning liquid pipe 32 (see FIG. 2) and the cleaning liquid supply unit 41 are connected via the conductive wire 82. Is grounded.

  FIG. 3 is a plan view of the induction electrode 6. The induction electrode 6 is made of conductive carbon (preferably glassy carbon such as amorphous carbon or glassy carbon) or conductive resin (for example, conductive PEEK or conductive PTFE). 3 is electrically insulated. As shown in FIGS. 2 and 3, the induction electrode 6 has an annular shape centering on the central axis 30 of the discharge port 31, surrounds the periphery of the discharge port 31 of the discharge unit 3, and is arranged on the central axis 30 of the discharge port 31. An inclined surface 61 that is inclined with respect to the inner side (that is, the central axis 30 side) is provided.

  In the present embodiment, the inclined surface 61 is a part of a spherical surface centered on the center of the discharge port 31. Accordingly, the inclined surface 61 has an annular shape surrounding the central axis 30 of the discharge port 31, and is a rotating surface around the central axis 30 (that is, an envelope surface when an object is rotated around the central axis 30). . Further, in an arbitrary cross section of the inclined surface 61 by the surface including the central axis 30, the distance between the central axis 30 and the inclined surface 61 in the direction perpendicular to the central axis 30 is the distance between the ejection unit 3 and the upper surface of the substrate 9. In the meantime, it gets longer as it approaches the discharge port 31.

  In the substrate processing apparatus 1, the central axis of the outer edge 611 of the inclined surface 61 of the induction electrode 6 (that is, the edge having a larger distance from the central axis 30 and the edge on the discharge port 31 side in the direction of the central axis 30). The position in the 30 direction coincides with the position in the direction of the central axis 30 of the discharge port 31.

  In the substrate processing apparatus 1 shown in FIG. 1, the induction electrode 6 is electrically connected to a power supply 81 outside the substrate processing apparatus 1, so that the cleaning liquid pipe 32 (see FIG. 2) that is a conductive liquid contact portion and the induction are used. A potential difference is applied to the electrode 6. As a result, a charge is induced in the cleaning liquid in the vicinity of the discharge port 31 of the discharge unit 3, and a droplet of the cleaning liquid having the charge is ejected from the discharge unit 3.

  Next, cleaning of the substrate 9 by the substrate processing apparatus 1 will be described. FIG. 4 is a diagram showing a flow of cleaning the substrate 9. In the substrate processing apparatus 1 shown in FIG. 1, first, after the substrate 9 is held by the chuck 21 of the substrate holding unit 2, the motor 222 of the rotation mechanism 22 is driven to start the rotation of the substrate 9 (step S11, S12).

  Subsequently, a potential difference is applied between the induction electrode 6 and the cleaning liquid tube 32 of the discharge unit 3, whereby charges are induced in a portion near the discharge port 31 of the discharge unit 3 (that is, the tip of the cleaning liquid tube 32). (Step S13). In the present embodiment, a positive charge is induced in the vicinity of the discharge port 31 of the discharge unit 3 by applying a potential of about −1000 V to the induction electrode 6.

  Next, the discharge unit moving mechanism 5 is driven to start the movement (ie, swing) of the discharge unit 3 and the induction electrode 6 (step S14). In the substrate processing apparatus 1, a positive charge is induced in the cleaning liquid in the vicinity of the discharge port 31 by supplying the cleaning liquid and nitrogen gas to the discharge unit 3 in a state where the charge is induced in the vicinity of the discharge port 31. At the same time, minute droplets of the cleaning liquid are generated, and the droplets of the cleaning liquid in which positive charges are induced are ejected (that is, discharged) toward the upper surface of the substrate 9 to clean the substrate 9 (step S15).

  The discharge unit 3 and the induction electrode 6 discharge the cleaning liquid toward the upper surface of the substrate 9 above the rotating substrate 9 and between the center and the peripheral portion of the substrate 9 in parallel with the upper surface of the substrate 9. By repeating reciprocating movement at a constant speed in an arc shape close to a straight line, droplets of the cleaning liquid are ejected onto the entire upper surface of the substrate 9 and foreign matters such as particles adhering to the upper surface are removed. In the substrate processing apparatus 1, while the droplets of the cleaning liquid are ejected to the substrate 9, the induction of the charge to the cleaning liquid in the vicinity of the discharge port 31 by the induction electrode 6 is continuously performed in parallel.

  When the ejection unit 3 is moved a predetermined number of times and the entire top surface is cleaned while the ejection of the cleaning liquid droplets onto the substrate 9 is continued, the ejection of the cleaning liquid from the ejection unit 3 and the ejection unit 3 is stopped, and application of a potential difference between the induction electrode 6 and the cleaning liquid pipe 32 (that is, induction of electric charge in the vicinity of the discharge port 31) is also stopped (step S16). Thereafter, the rotation of the substrate 9 is continued and dried, and then the rotation of the substrate 9 is stopped (step S17). The substrate 9 is unloaded from the substrate processing apparatus 1 and the cleaning process for the substrate 9 is completed (step S17). S18).

  In the substrate processing apparatus 1, fine droplets of the cleaning liquid collide with the upper surface of the substrate 9 at a high speed, so that the fine pattern formed on the upper surface is not damaged, and the minute matter such as organic matter adhering to the upper surface is damaged. Particles can be efficiently removed.

  By the way, when a cleaning process is performed on a substrate having an oxide film formed on the upper surface without performing charge induction on the cleaning liquid, the upper surface of the substrate is negatively charged. Note that the substrate is hardly charged in the state before cleaning, and it is considered that the above-described charging is caused by the cleaning process. In the substrate processing apparatus 1, by applying a potential difference between the induction electrode 6 and the cleaning liquid tube 32, a charge having a polarity opposite to the substrate potential after cleaning when the potential difference is not applied (that is, positive) The droplets of the cleaning liquid in which the charge is induced are generated, and the substrate 9 is cleaned by the droplets of the cleaning liquid, thereby suppressing charging of the substrate 9 during and after cleaning (that is, charging of the substrate 9 by the cleaning process). can do.

  In the substrate processing apparatus 1, by providing the induction electrode 6 in the vicinity of the discharge port 31 of the discharge unit 3, it is possible to easily realize charge induction for the cleaning liquid droplets while simplifying the structure of the substrate processing apparatus 1. .

  In the induction electrode 6, the distance between the central axis 30 and the inclined surface 61 is increased as the distance from the discharge port 31 becomes closer in an arbitrary cross section including the central axis 30 of the inclined surface 61 surrounding the discharge port 31. . With the induction electrode 6 having such a shape, for example, compared to a case where an annular plate-like induction electrode surrounding the discharge port 31 is provided, the induction electrode 6 at a position close to the discharge port 31 is provided. Since the area can be increased, charges can be efficiently induced in the cleaning liquid. As a result, it is possible to efficiently suppress charging of the substrate 9.

  Further, the inclined surface 61 of the induction electrode 6 is an annular surface surrounding the central axis 30 of the discharge port 31 and is a rotating surface centered on the central shaft 30, so that the discharge port 31 is not hindered from discharging the cleaning liquid. Electric charges can be induced approximately uniformly in the vicinity. Furthermore, since the inclined surface 61 is a part of a spherical surface centered on the center of the discharge port 31, the distance from the discharge port 31 can be made uniform over the entire inclined surface 61. By increasing the area of the surface as close as possible to the discharge port 31, it is possible to induce charges in the cleaning liquid more efficiently.

  In the induction electrode 6, the position of the outer edge 611 of the inclined surface 61 in the direction of the central axis 30 coincides with the position of the discharge port 31 in the direction of the central axis 30. Since it can be induced, electric charges can be induced in the cleaning liquid more efficiently.

  In the substrate processing apparatus 1, by using a two-fluid nozzle as the ejection unit 3, it is possible to easily generate droplets of the cleaning liquid, and it is possible to reduce the size of the mechanism related to the generation and ejection of the droplets. Further, there is a case where the substrate 9 is provided with copper wiring or the like that may be deteriorated by contact with an acidic solution (for example, carbon dioxide-dissolved water) by using neutral pure water as the cleaning liquid. However, the cleaning process for the substrate 9 can be performed while suppressing the charging of the substrate 9 without deteriorating these wirings.

  Next, a substrate processing apparatus according to a second embodiment of the present invention will be described. FIG. 5 is a longitudinal sectional view showing the vicinity of the discharge unit 3 of the substrate processing apparatus according to the second embodiment. As shown in FIG. 5, the substrate processing apparatus according to the second embodiment includes an induction electrode 6a having a shape different from that of the induction electrode 6 of the substrate processing apparatus 1 shown in FIG. Other configurations are the same as those in FIGS. 1 and 2, and are denoted by the same reference numerals in the following description.

  FIG. 6 is a plan view showing the induction electrode 6a. As shown in FIGS. 5 and 6, the induction electrode 6 a has an annular shape centering on the central axis 30 of the discharge port 31 of the discharge unit 3, surrounds the periphery of the discharge port 31, and is arranged on the central axis 30 of the discharge port 31. An inclined surface 61a that is inclined with respect to the inner side (that is, the central axis 30 side) is provided.

  In the present embodiment, the inclined surface 61a is a part of a conical surface having an apex on the central axis 30 of the discharge port 31 on the substrate 9 (see FIG. 1) side of the discharge port 31, and the generatrix of the conical surface And the central axis 30 is 45 °. Further, the position of the outer edge 611 of the inclined surface 61a in the direction of the central axis 30 coincides with the position of the discharge port 31 in the direction of the central axis 30.

  The flow of cleaning the substrate 9 by the substrate processing apparatus according to the second embodiment is the same as that of the first embodiment (see FIG. 4), and a potential difference is applied between the induction electrode 6a and the cleaning liquid tube 32. In this way, charge is induced in the cleaning liquid, and the substrate 9 is cleaned with the liquid droplets of the cleaning liquid, whereby charging of the substrate 9 during and after cleaning can be suppressed.

  In the substrate processing apparatus according to the second embodiment, in an arbitrary cross section of the inclined surface 61a of the induction electrode 6a by the surface including the central axis 30, the central axis 30 and the inclined surface 61a with respect to the direction perpendicular to the central axis 30. The distance between the discharge portion 3 and the upper surface of the substrate 9 becomes longer as it approaches the discharge port 31. Accordingly, for example, the area of the induction electrode 6 at a position close to the discharge port 31 can be increased as compared with a case where an annular plate-shaped induction electrode surrounding the periphery of the discharge port 31 is provided. Charge can be induced efficiently. Further, the inclined surface 61a of the induction electrode 6a is an annular surface surrounding the central axis 30 of the discharge port 31 and is a rotating surface centered on the central axis 30, so that the discharge port 31 is not hindered from discharging the cleaning liquid. Electric charges can be induced approximately uniformly in the vicinity.

  In the induction electrode 6a, the inclined surface 61a is formed as a part of a conical surface, so that the inclined surface 61a can be easily formed by cutting or the like. Further, since the angle formed by the generatrices of the inclined surface 61a and the central axis 30 is 45 °, the inclined surface 61a is evenly placed on the discharge port 31 on both the discharge port 31 side and the substrate 9 side of the inclined surface 61a. Since it can be made to adjoin, an electric charge can be induced | guided | derived to a washing | cleaning liquid more efficiently.

Next, a substrate processing apparatus according to a third embodiment of the present invention will be described. FIG. 7 is a diagram showing a substrate processing apparatus 1a according to the third embodiment. In the substrate processing apparatus 1a, carbon dioxide-dissolved water obtained by dissolving carbon dioxide (CO ₂ ) in pure water is used as the cleaning liquid. As shown in FIG. 7, the substrate processing apparatus 1 a further includes a gas-liquid mixer 43 that generates carbon dioxide-dissolved water in addition to the configuration of the substrate processing apparatus 1 shown in FIG. 1. Other configurations are the same as those in FIG. 1 and FIG.

  As shown in FIG. 7, in the substrate processing apparatus 1 a, a gas-liquid mixer 43 is connected to a cleaning liquid supply unit 41 that guides the cleaning liquid to the discharge unit 3, and pure water supply (not shown) is supplied to the gas-liquid mixer 43. A pure water supply pipe 44 and a carbon dioxide gas supply pipe 45 are connected to the source and the carbon dioxide gas supply source, respectively.

  Inside the gas-liquid mixer 43, a gas permeable and liquid impermeable gas dissolving membrane formed by a hollow fiber separation membrane or the like is provided. In the gas-liquid mixer 43, pure water and carbon dioxide are individually supplied to two supply chambers separated by a gas dissolution film, and the pressure of carbon dioxide is made higher than the pressure of pure water. Carbon dioxide gas permeates through the gas-dissolving membrane and dissolves in pure water to generate carbon dioxide-dissolved water. Note that unnecessary gas dissolved in pure water is degassed by a vacuum pump (not shown).

In the gas-liquid mixer 43, the supply pressure or the like of carbon dioxide or pure water is controlled so that the specific resistance of the carbon dioxide dissolved water becomes a predetermined value. The specific resistance of the carbon dioxide-dissolved water is preferably 1 × 10 ² Ωm or more and 4 × 10 ³ Ωm or less (more preferably 5 × 10 ² Ωm or more and 4 × 10 ³ Ωm or less). , Approximately 1 × 10 ³ Ωm.

  In the substrate processing apparatus 1a, as in the first embodiment, the substrate 9 is cleaned with the droplets of the cleaning liquid in which the charge is induced, so that charging of the substrate 9 during and after cleaning can be suppressed. . In addition, since the inclined surface 61 is provided on the induction electrode 6, the area of the induction electrode 6 at a position close to the discharge port 31 can be increased, so that charges can be efficiently induced in the cleaning liquid.

  In the substrate processing apparatus 1a, in particular, by using carbon dioxide-dissolved water having a specific resistance lower than that of pure water (that is, having high conductivity) as the cleaning liquid, the substrate 9 generated when the cleaning liquid droplets collide with the substrate 9 is used. The charging on the upper surface of the substrate can be further suppressed.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the said embodiment, A various change is possible.

  In the substrate processing apparatus 1 according to the first embodiment, the center of the spherical surface on which the inclined surface 61 of the induction electrode 6 is a part may be shifted from the center of the discharge port 31, for example, toward the substrate 9. Even in this case, since the distance between the inclined surface 61 and the discharge port 31 is approximately uniform, charges can be more efficiently induced in the cleaning liquid.

  In the induction electrode of the substrate processing apparatus according to the above embodiment, the outer edge 611 of the inclined surface does not necessarily coincide with the discharge port 31 in the direction of the central axis 30, for example, the discharge port 31 and the substrate 9. It may be located between.

  8, FIG. 9, FIG. A, FIG. B and FIG. FIG. 10A is a longitudinal sectional view showing an example of an induction electrode having an inclined surface having a shape different from that of the above embodiment, and FIG. C and FIG. B is a plan view of the induction electrode. In the induction electrode 6 b shown in FIG. 8, the outer surface 62 of the inclined surface 61 that is a part of the spherical surface is also inclined with respect to the central axis 30. In the induction electrode 6 c shown in FIG. 9, the inclined surface 61 b is a rotating surface obtained by rotating an arc having a central angle of 90 ° away from the central axis 30.

  FIG. A and FIG. B shows the induction electrode 6d as shown in FIG. It is sectional drawing cut | disconnected in the position of AA and BB in C. In the induction electrode 6d, the inner edge 612 and the outer edge 611 of the inclined surface 61c are substantially rectangular in plan view (specifically, the corner is a chamfered shape with a circular arc shape). Among the inclined surfaces 61c, four surfaces having the respective straight sides of the rectangle as inner and outer edges are shown in FIG. As shown in FIG. 10A, the surfaces of the four corners which are cylindrical surfaces and sandwiched between the four planes are shown in FIG. As shown in B, it is a part of a spherical surface.

  FIG. A and FIG. In the induction electrode 6e shown in B, the inclined surface 61d is a part of a quadrangular pyramid surface having a vertex on the central axis 30 of the discharge port on the substrate side of the discharge port of the substrate processing apparatus. The inclined surface of the induction electrode may be a part of a polygonal pyramid surface other than a quadrangular pyramid surface having a vertex on the central axis of the discharge port, or may be a convex surface that is convex with respect to the discharge port. .

  The liquid contact portion of the discharge unit 3 to which a potential difference is applied between the induction electrode and the induction electrode is not necessarily provided in the cleaning liquid pipe 32. For example, the cleaning liquid supply unit 41 may be grounded via the conductive wire 82. Further, the application of the potential difference between the induction electrode and the liquid contact part on the discharge unit 3 side may be performed, for example, by grounding the induction electrode and connecting the liquid contact part to the power source 81. These two electrodes may be connected to the induction electrode and the liquid contact part, respectively. However, from the viewpoint of simplifying the structure of the substrate processing apparatus, it is preferable that the liquid contact portion is grounded and the induction electrode is connected to the power source 81 as in the above embodiment.

  The discharge unit 3 is not necessarily limited to the internal mixing type two-fluid nozzle. For example, the cleaning liquid and the carrier gas are individually ejected to the outside of the discharge unit, and mixed in the vicinity of the discharge port 31 to mix the cleaning liquid. It may be an externally mixed two-fluid nozzle that generates drops. Further, in the substrate processing apparatus, the droplets of the cleaning liquid generated by another apparatus may be supplied to the discharge unit 3 and the droplets may be ejected from the discharge unit 3 together with the carrier gas. May be supplied and ejected as droplets.

  In the substrate processing apparatus, the droplets of the cleaning liquid do not necessarily have to be discharged from the discharge unit 3. For example, the substrate 9 may be cleaned by discharging the cleaning liquid in a columnar flow, and ultrasonic waves may be generated. The substrate 9 may be cleaned by discharging the applied cleaning liquid. As described above, since the substrate processing apparatus can suppress charging due to cleaning of the substrate 9, it is particularly suitable for cleaning with droplets in which the charge amount of the substrate 9 is larger than cleaning with a liquid column.

  In the substrate processing apparatus according to the above-described embodiment, the polarity of the potential of the substrate and the amount of charge generated by the cleaning are determined depending on the type of substrate (for example, the type of insulating film and the type of wiring metal on the upper surface of the semiconductor substrate, and combinations thereof). Therefore, the potential difference applied between the induction electrode and the ejection unit 3 in the substrate processing apparatus is variously changed according to the type of the substrate. For example, when a resist film is formed on the substrate, the upper surface of the substrate is positively charged by cleaning, so that a positive voltage is applied to the induction electrode and a negative charge is induced in the cleaning liquid.

In the substrate processing apparatus according to the first and second embodiments, a liquid other than pure water may be used as the cleaning liquid. For example, ZEOLOR (registered trademark) of Nippon Zeon Corporation, which is a fluorine-based cleaning liquid, or 3M A liquid having a relatively high specific resistance such as Novec (registered trademark) HFE (specific resistance: 3.3 × 10 ⁷ Ωm) may be used as the cleaning liquid. Further, in the substrate processing apparatus 1a according to the third embodiment, instead of carbon dioxide-dissolved water, a rare gas such as xenon (Xe), methane gas, or the like is dissolved in pure water, or hydrochloric acid or ammonia water An aqueous solution in which a chemical solution such as hydrogen peroxide is slightly mixed with pure water may be used as a cleaning solution having a specific resistance lower than that of pure water. When a chemical solution such as hydrochloric acid or ammonia is dissolved in pure water, a mixing valve or the like is used instead of the gas-liquid mixer 43. As described above, since the substrate processing apparatus according to the above-described embodiment can suppress charging due to cleaning of the substrate 9, the specific resistance for increasing the charge amount of the substrate 9 is higher than that of the cleaning liquid having a low specific resistance. It is particularly suitable for cleaning with a cleaning solution (that is, a cleaning solution having a specific resistance of 1 × 10 ² Ωm or more).

  The substrate processing apparatus according to the above embodiment may be used for various processes other than the cleaning of the substrate. For example, the substrate processing apparatus may be used for a rinsing process of the substrate after the chemical solution cleaning. In this case, a rinsing liquid such as pure water is used as a processing liquid supplied to the substrate. Further, the substrate processing apparatus may be used for processing various substrates other than the semiconductor substrate such as a glass substrate used for a printed wiring board or a flat panel display device.

It is a figure which shows the substrate processing apparatus which concerns on 1st Embodiment. It is a longitudinal cross-sectional view which shows the discharge part vicinity. It is a top view of an induction electrode. It is a figure which shows the flow of washing | cleaning of a board | substrate. It is a longitudinal cross-sectional view which shows the discharge part vicinity of the substrate processing apparatus which concerns on 2nd Embodiment. It is a top view of an induction electrode. It is a figure which shows the substrate processing apparatus which concerns on 3rd Embodiment. It is a longitudinal section showing other examples of an induction electrode. It is a longitudinal section showing other examples of an induction electrode. It is a longitudinal section showing other examples of an induction electrode. It is a longitudinal cross-sectional view of an induction electrode. It is a top view of an induction electrode. It is a longitudinal section showing other examples of an induction electrode. It is a top view of an induction electrode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a Substrate processing apparatus 3 Discharge part 6,6a-6e Induction electrode 9 Substrate 30 Center axis 31 Discharge port 32 Cleaning liquid pipe 41 Cleaning liquid supply part 61, 61a-61d Inclined surface 611 Edge

Claims (11)

A substrate processing apparatus for processing a substrate by supplying a processing liquid to the substrate,
A discharge unit that discharges the processing liquid toward the main surface of the substrate;
A processing liquid supply section for guiding the processing liquid to the discharge section;
Conductive liquid contact between the discharge part and the main surface of the substrate in the vicinity of the discharge port of the discharge part while being electrically insulated from the discharge part. An induction electrode that induces a charge in the treatment liquid in the vicinity of the discharge port by applying a potential difference between
With
The induction electrode has an inclined surface that surrounds the periphery of the discharge port of the discharge unit and is inclined with respect to the central axis of the discharge port, and in an arbitrary cross section of the inclined surface by a surface including the central axis, A distance between the central axis and the inclined surface with respect to a direction perpendicular to the central axis is longer as the distance from the ejection portion and the main surface of the substrate approaches the ejection port. Substrate processing equipment. The substrate processing apparatus according to claim 1,
The substrate processing apparatus, wherein the inclined surface of the induction electrode is an annular surface surrounding the central axis of the discharge port, and is a rotating surface centered on the central axis. The substrate processing apparatus according to claim 2,
The substrate processing apparatus, wherein the inclined surface of the induction electrode is a part of a spherical surface centered on the center of the discharge port. The substrate processing apparatus according to claim 2,
The substrate processing apparatus, wherein the inclined surface of the induction electrode is a part of a conical surface having an apex on the central axis of the discharge port. The substrate processing apparatus according to claim 4,
The substrate processing apparatus characterized in that an angle formed between a generatrix of the conical surface and the central axis is 45 °. A substrate processing apparatus according to any one of claims 1 to 5,
The position of the outer edge of the inclined surface in the central axis direction coincides with the position of the discharge port in the central axis direction. A substrate processing apparatus according to any one of claims 1 to 6,
The substrate processing apparatus, wherein the discharge unit ejects droplets of the processing liquid toward the substrate. The substrate processing apparatus according to claim 7,
The substrate processing apparatus, wherein the discharge unit generates the droplets of the processing liquid by mixing the processing liquid and a carrier gas in the discharge unit or in the vicinity of the discharge port. A substrate processing apparatus according to any one of claims 1 to 8,
The substrate processing apparatus characterized in that the specific resistance of the processing liquid is 1 × 10 ² Ωm or more. The substrate processing apparatus according to claim 9, comprising:
A substrate processing apparatus, wherein the processing liquid is pure water. The substrate processing apparatus according to claim 9, comprising:
The substrate processing apparatus, wherein the processing liquid is carbon dioxide-dissolved water obtained by dissolving carbon dioxide in pure water.

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