JP4771845B2 - Substrate processing method and storage medium - Google Patents

Description

  The present invention relates to a substrate processing method and a storage medium, and more particularly to a substrate processing method in a substrate processing system including an etching apparatus having an electrostatic chuck that electrostatically attracts a substrate.

  A substrate processing system that forms a wiring groove or a via hole with a desired pattern using plasma on the surface of a wafer as a substrate is a coater that applies a positive resist to the surface of a wafer, and a resist that is cured by heating or the like. An exposure machine that exposes a portion of the wafer, a developer that forms a resist film by removing the resist exposed from the wafer surface with a developer, and an etching process such as RIE (Reactive Ion Etching) on the wafer surface. An apparatus and a cleaning apparatus for removing the resist film. In recent years, in a substrate processing system, a coater and a developer are often integrated from the viewpoint of space saving.

  The etching apparatus also includes a storage chamber that stores the wafer and generates plasma, and an electrostatic chuck that is disposed in the storage chamber and electrostatically attracts the wafer while the wafer is being etched. (For example, refer to Patent Document 1).

  The exposure apparatus irradiates the resist on the wafer surface with ultraviolet light having a pattern reversed with respect to the desired mask pattern. Recently, with the miniaturization of the desired mask pattern, ultraviolet light having a short wavelength, for example, wavelength of 193 nm is used. Is used in the exposure machine. When the wavelength is short, the depth of focus is also reduced, and the flatness and tilt of the allowable wafer are also reduced. In particular, since a plurality of pin-shaped protrusions support the back surface of the wafer in the exposure machine, scratches, foreign matter, etc. on the back surface of the wafer greatly affect the flatness and tilt of the wafer.

By the way, in order to realize a complicated wiring structure and electrode structure for a semiconductor device on a wafer, the wafer is repeatedly subjected to an etching process by a substrate processing system. Adsorbed. Since the surface of the electrostatic chuck is covered with yttria (Y ₂ O ₃ ), the back surface of the wafer made of adsorbed silicon (Si) may be damaged. In addition, foreign matter existing on the surface of the electrostatic chuck may be transferred and adhered to the back surface of the wafer.
JP 2005-347620 A

  However, foreign matter adhering to the back surface of the wafer can be removed by wet cleaning using a cleaning liquid or the like, but a method for effectively removing scratches on the back surface of the wafer is not known. As described above, the flatness of the wafer that is allowed due to scratches on the back surface of the wafer may not be maintained. Also, yttria or the like may be peeled off (dusted) and become particles due to scratches on the backside of the wafer and rubbing on the surface of the electrostatic chuck. Therefore, it is necessary to prevent the back surface of the wafer from being damaged when the wafer is attracted to the electrostatic chuck.

  An object of the present invention is to provide a substrate processing method and a storage medium that can prevent the back surface of a substrate from being damaged as a result of disturbing the flatness of the substrate and causing generation of particles.

In order to achieve the above object, a substrate processing method according to claim 1 includes at least an etching apparatus that performs plasma etching on a substrate, and the etching apparatus includes an electrostatic chuck that electrostatically attracts the substrate, the electrostatic chuck is a substrate processing method in the substrate processing system in contact with the back surface of the substrate, a coating step of applying a photocurable resin on the back surface of the substrate, the hardenable resin coated on the back surface of the substrate a curing step that form a protective layer is cured by exposure, a reversing step of reversing the front and back surfaces of the substrate, and the resist film forming step of forming a resist film having a predetermined mask pattern on the surface of the substrate, the substrate to the etching step of the surface of performing the plasma etching treatment, a cleaning step of removing the protective film, characterized by having a .

In order to achieve the above object, the substrate processing method according to claim 2 includes at least an etching apparatus that performs a plasma etching process on the substrate, and the etching apparatus includes an electrostatic chuck that electrostatically attracts the substrate, The electrostatic chuck is a substrate processing method in a substrate processing system that comes into contact with the back surface of a substrate, wherein a resist film forming step of forming a resist film having a predetermined mask pattern on the surface of the substrate and the front and back surfaces of the substrate are reversed. A first inversion step, an application step of applying a photocurable resin to the back surface of the substrate, a curing step of forming a protective film by curing the curable resin applied to the back surface of the substrate by exposure, A second inversion step for inverting the front and back surfaces of the substrate; an etching step for performing the plasma etching process on the surface of the substrate; It characterized by having a a cleaning step of removing the protective film.

The substrate processing method according to claim 3 is the substrate processing method according to claim 1 or 2, wherein the light used for the exposure is ultraviolet light .

The substrate processing method according to claim 4 is the substrate processing method according to any one of claims 1 to 3 , wherein the electrostatic chuck is any one of Y ₂ O ₃ , Al ₂ O _{3, and} SiO _2. It is formed .

In order to achieve the above object, a storage medium according to claim 5 includes at least an etching apparatus for performing a plasma etching process on a substrate, and the etching apparatus includes an electrostatic chuck for electrostatically attracting the substrate. The electric chuck is a computer-readable storage medium storing a program for causing a computer to execute a substrate processing method in a substrate processing system in contact with the back surface of the substrate, and the substrate processing method includes a photocurable resin on the back surface of the substrate. A coating step for coating the substrate, a curing step for curing the curable resin applied to the back surface of the substrate by exposure to form a protective film, a reversing step for inverting the front and back surfaces of the substrate, and a surface of the substrate A resist film forming step for forming a resist film having a predetermined mask pattern; and the plasma etch on the surface of the substrate. And having an etching step of subjecting the packaging process, a cleaning step of removing the protective film.

In order to achieve the above object, a storage medium according to claim 6 includes at least an etching apparatus that performs plasma etching on a substrate, and the etching apparatus includes an electrostatic chuck that electrostatically attracts the substrate. The electric chuck is a computer-readable storage medium that stores a program for causing a computer to execute a substrate processing method in a substrate processing system in contact with the back surface of the substrate, and the substrate processing method has a predetermined mask pattern on the surface of the substrate. A resist film forming step for forming the resist film, a first inversion step for inverting the front and back surfaces of the substrate, a coating step for applying a photocurable resin to the back surface of the substrate, and a back surface of the substrate. Curing step of curing the cured resin by exposure to form a protective film, and reversing the front and back surfaces of the substrate A second reversing step, and having an etching step of performing the plasma etching treatment on the surface of the substrate, a cleaning step of removing the protective film.

According to the substrate processing method described in claims 1 and 2 and the storage medium described in claims 5 and 6 , the electrostatic chuck contacts a protective film formed by curing the curable resin on the back surface of the substrate. Therefore, when the substrate is attracted to the electrostatic chuck, it is possible to prevent the back surface of the substrate from being scratched which disturbs the flatness of the substrate and causes generation of particles.

According to claim 1 the substrate processing method and claim 5, wherein the storage medium, wherein it is possible to perform formation of forming the resist film of the coercive Mamorumaku separately with, the stable protective film and the resist film, respectively Can be formed. In addition, when the surface of the substrate is exposed to form a resist film, the back surface of the substrate is supported by pin-shaped protrusions, but since a protective film is interposed between the back surface and the protrusions of the substrate, It can support stably and can perform exposure stably.

According to the storage medium of a substrate processing method and claim 6 according to claim 2, it is possible to perform the formation of the formation of the resist film of the coercive Mamorumaku separately with, the stable protective film and the resist film, respectively Can be formed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, a substrate processing system that executes a substrate processing method according to a first embodiment of the present invention will be described.

  FIG. 1 is a diagram showing a schematic configuration of a substrate processing system that executes a substrate processing method according to the present embodiment.

  In FIG. 1, a substrate processing system 10 includes a coater / developer 11, an etching device 13, a cleaning device 14, and guide rails arranged in parallel with the coater / developer 11, the etching device 13, and the cleaning device 14. 15, an AGV (Automatic Guided Vehicle) 16, and an exposure machine 12 arranged adjacent to the coater / developer 11.

  The coater / developer 11 applies a resist, which is a positive curable resin, to the surface of a semiconductor device wafer (hereinafter simply referred to as “wafer”) (substrate) W, and applies ultraviolet light to the back surface of the wafer W. The function of a coater for applying a photocurable resin that is cured by irradiation, and a resist that has been subjected to exposure processing of a pattern reversed with respect to a predetermined mask pattern by an exposure machine 12 among resists cured by heating or the like after application. It has the function of a developer that forms a resist film or the like having a predetermined mask pattern by removing using an alkaline cleaning solution.

  The exposure machine 12 includes a mounting table (not shown) having pin-shaped protrusions on the surface for supporting the wafer W, and an ultraviolet irradiation lamp (not shown) arranged facing the mounting table. The resist applied to the surface is exposed by irradiating with ultraviolet rays to expose the resist. Here, since the resist is irradiated with ultraviolet rays only on the portion corresponding to the pattern inverted with respect to the predetermined mask pattern, the resist of the inverted pattern is altered and becomes alkali-soluble. Further, when exposure processing is performed on the resist in the exposure machine 12, the wafer W is supported by the pin-shaped protrusions of the mounting table.

  The etching apparatus 13 includes a transport system for transporting the wafer W and a plurality of process modules 17 (to be described later) for performing RIE processing on the surface of the wafer W.

  The cleaning device 14 removes the resist film formed on the front surface of the wafer W and the resin protective film formed on the back surface with a cleaning liquid.

  The AGV 16 is a transport robot that can move along the guide rail 15. The AGV 16 mounts a wafer cassette CR, which is a container in which a plurality of wafers W are accommodated, on each apparatus, for example, the wafer cassette CR to the coater / developer 11. Carry in and out. The AGV 16 conveys the wafer cassette CR in the order of the coater / developer 11, the etching device 13 and the cleaning device 14.

  FIG. 2 is a front view showing a schematic configuration of the coater / developer in FIG.

  In FIG. 2, a coater / developer 11 includes a cassette station 18 that transfers a wafer cassette CR to and from the AGV 16, and a processing station that applies a resist or a photocurable resin to the wafer W and develops a resist film or the like. 19 and an interface unit 20 for transferring the wafer W between the exposure machine 12. The cassette station 18, the processing station 19, and the interface unit 20 are integrally connected. The cassette station 18 not only delivers the wafer cassette CR to and from the AGV 16, but also carries the wafer W in and out of the wafer cassette CR.

  The processing station 19 includes various single-wafer processing units that perform predetermined processing one by one on the wafer W, which are arranged in multiple stages. Various processing units arranged in multiple stages constitute a unit set. The processing station 19 includes a plurality of unit sets, a wafer transfer mechanism (not shown) that is disposed so as to be surrounded by each unit set, and delivers the wafer W to each unit set, and a wafer that reverses the delivered wafer W upside down. And a reversing unit (not shown). Of the plurality of unit sets, the unit sets 21a and 21b are overlapped on the coating unit 22c, the two coating units (coaters) 22a and 22c, the wafer reversing unit 22b disposed between the coating units 22a and 22c, respectively. A curing unit 82a, and two developing units (developers) 82b and 82c stacked on the curing unit 82a. Another unit set (not shown) includes an oven unit having a mounting table on which the wafer W is mounted.

  Each of the coating units 22a and 22c applies a resist to the front surface of the wafer W, and applies a photocurable resin to the back surface of the wafer W. The developing units 82b and 82c remove the resist that has been subjected to the exposure process from the surface of the wafer and changed to alkali-soluble by using an alkaline developer. Thus, the developing units 82b and 82c form a resist film or the like having a predetermined mask pattern. The curing unit 82a performs an exposure process by irradiating the photocurable resin applied to the back surface of the wafer W with ultraviolet rays to cure the photocurable resin. The oven unit cures the resist applied to the surface of the wafer W by heating.

  FIG. 3 is a cross-sectional view showing a schematic configuration of the coating unit in FIG.

  In FIG. 3, the coating unit 22 a is disposed so as to surround the chamber 23 as a housing-like storage chamber for storing the wafer W, the spin chuck 24 disposed at the center of the chamber 23, and the spin chuck 24. An annular cup 25 and a resist discharge mechanism 26 are provided.

  The spin chuck 24 is made of PEEK resin, is connected to a spin motor (not shown), and rotates with the wafer W mounted thereon. The wafer W placed on the spin chuck 24 rotates in a horizontal plane. Further, the spin chuck 24 is moved up and down by an air cylinder (not shown) or the like. The wafer W is chucked on the spin chuck 24 by a mechanical chuck or a vacuum chuck (both not shown).

  The cup 25 is an annular container, and has an opening 29 whose upper part opens over the entire circumference. When the wafer W vacuum-sucked on the mounting table 27 is lowered, the opening 29 accommodates the peripheral edge of the wafer W. The cup 25 has an excess liquid discharge pipe 30 at the bottom.

  The resist discharge mechanism 26 connects a nozzle 31 disposed so as to face the wafer W vacuum-sucked on the upper surface of the mounting table 27 and a resist supply device (not shown) that supplies the nozzle 31 and the resist to each other. It has a supply pipe 32, a nozzle holder 33 to which the nozzle 31 is detachably attached, and a nozzle scan arm 34 having the nozzle holder 33 at the tip. The nozzle scan arm 34 is attached to the upper end of a vertical support member 36 that can be moved horizontally by a guide rail 35 laid on the bottom of the chamber 23, and can move freely in the depth direction in the figure integrally with the vertical support member 36. To do.

  Further, on the side wall of the chamber 23, a wafer W loading / unloading port 37 is provided at a position corresponding to the height of the wafer W lifted upward by the spin chuck 24.

  In the coating unit 22, the nozzle 31 discharges the resist toward the surface of the wafer W that rotates in a horizontal plane. When the discharged resist reaches the surface of the wafer W, it spreads uniformly on the surface of the wafer W by centrifugal force. Thereby, a resist is uniformly applied to the surface of the wafer W (spin coating process). At this time, the surplus resist is captured by the cup 25 and discharged to the outside by the surplus liquid discharge pipe 30.

  In addition, the coating unit 22 c has a photocurable resin discharge mechanism that discharges a photocurable resin instead of the resist discharge mechanism 26. Here, before the wafer W is carried into the chamber 23 of the coating unit 22c, the front and back are reversed by the wafer reversing unit 22b. Therefore, in the coating unit 22c, the back surface of the wafer W and the photocurable resin discharge mechanism face each other. Examples of the photocurable resin used in the coating unit 22c include a resin having a carboxyl group and containing a cellulose derivative having an acid value of 30 to 220 KOHmg / g. In addition, a thermosetting resin, for example, a resin containing polyimide may be applied to the back surface of the wafer W in the coating unit 22c instead of the photocurable resin.

  The wafer reversing unit 22b has a mechanical chuck that holds the periphery of the wafer W. Therefore, in the wafer reversing unit 22b, the surface of the wafer W does not come into contact with the mechanical chuck, and the semiconductor device formed on the surface can be prevented from being damaged.

  In the coater / developer 11, the wafer W carried out of the wafer cassette CR is reversed by the wafer reversing unit 22b, and the photocurable resin is first coated on the back surface of the wafer W by the coating unit 22c. When the wafer W is unloaded from the coating unit 22c, the wafer W is loaded into the curing unit 82a. The curing unit 82a performs exposure processing by irradiating the photocurable resin applied to the back surface of the wafer W with ultraviolet rays, so that the photocurable resin is exposed. Is cured. Thereby, the photocurable resin applied to the back surface becomes a resin protective film. Thereafter, the wafer W is turned upside down by the wafer turning unit 22b. A resist is applied to the surface of the wafer W whose front and back are turned upside down in the coating unit 22a. Then, when the wafer W is unloaded from the coating unit 22a, the wafer W is loaded into the oven unit. The unit cures the resist applied on the surface of the wafer W by heating. Thereafter, the wafer W is carried into the exposure machine 12 by the interface unit 20 and placed on the mounting table. At this time, an ultraviolet ray is irradiated only to a portion corresponding to a pattern inverted with respect to a predetermined mask pattern from the ultraviolet irradiation lamp toward the surface of the wafer W, and an exposure process is performed. As a result, the resist having a reversed pattern on the surface of the wafer W is altered and becomes alkali-soluble.

  The wafer W, on which the resist has been subjected to the exposure process of the inverted pattern, is carried into the coater / developer 11 by the interface unit 20, and is inverted from the surface to be alkali-soluble by an alkaline developer in the developing units 82b and 82c. The resist having the pattern is removed. As a result, a resist film or the like having a predetermined mask pattern is formed on the surface of the wafer W.

  FIG. 4 is a cross-sectional view showing a schematic configuration of a process module of the etching apparatus in FIG.

  In FIG. 4, the process module 17 has a chamber 38 for storing a wafer W, and a cylindrical susceptor 39 as a mounting table for mounting the wafer is disposed in the chamber 38.

  In the process module 17, a side exhaust path 40 that functions as a flow path for discharging the gas above the susceptor 39 out of the chamber 38 is formed by the inner wall of the chamber 38 and the side surface of the susceptor 39. A baffle plate 41 is disposed in the middle of the side exhaust passage 40.

  The baffle plate 41 is a plate-like member having a large number of holes, and functions as a partition plate that partitions the chamber 38 into an upper part and a lower part. A susceptor 39 or the like on which the wafer W is placed is disposed on the upper portion 42 of the chamber 38 partitioned by the baffle plate 41, and plasma is generated. Hereinafter, the upper part 42 of the chamber 38 is referred to as a “reaction chamber”. In addition, a rough exhaust pipe 44 and a main exhaust pipe 45 for discharging the gas in the chamber 38 are opened in a lower portion 43 (hereinafter referred to as “exhaust chamber (manifold)”) of the chamber 38. A DP (Dry Pump) (not shown) is connected to the roughing exhaust pipe 44, and a TMP (Turbo Molecular Pump) (not shown) is connected to the main exhaust pipe 45. Further, the baffle plate 41 captures or reflects ions and radicals generated in a processing space S (described later) of the reaction chamber 42 to prevent leakage to these manifolds 43.

  The roughing exhaust pipe 44, the main exhaust pipe 45, DP, TMP and the like constitute an exhaust device, and the rough exhaust pipe 44 and the main exhaust pipe 45 exhaust the gas in the reaction chamber 42 to the outside of the chamber 38 through the manifold 43. To do. Specifically, the roughing exhaust pipe 44 reduces the pressure in the chamber 38 from atmospheric pressure to a low vacuum state, and the main exhaust pipe 45 cooperates with the roughing exhaust pipe 44 in the chamber 38 from the atmospheric pressure to a low vacuum state. The pressure is reduced to a high vacuum state (for example, 133 Pa (1 Torr or less)) which is a lower pressure.

  A lower high frequency power supply 46 is connected to the susceptor 39 via a matching unit 47, and the lower high frequency power supply 46 supplies predetermined high frequency power to the susceptor 39. Thereby, the susceptor 39 functions as a lower electrode. In addition, the matching unit 47 reduces the reflection of the high frequency power from the susceptor 39 to maximize the supply efficiency of the high frequency power to the susceptor 39.

An insulating member having an electrode plate 48 inside, for example, a disc-shaped electrostatic chuck 49 made of yttria, alumina (Al ₂ O ₃ ) or silica (SiO ₂ ) is disposed on the susceptor 39. . When the susceptor 39 places the wafer W, the wafer W is placed on the electrostatic chuck 49. A DC power supply 50 is electrically connected to the electrode plate 48. When a negative DC voltage is applied to the electrode plate 48, a positive potential is generated on the back surface of the wafer W, and a negative potential is generated on the front surface of the wafer. Then, a potential difference is generated between the electrode plate 48 and the back surface of the wafer W, and the wafer W is attracted and held on the upper surface of the electrostatic chuck 49 by Coulomb force or Johnson-Rahbek force resulting from the potential difference.

  An annular focus ring 51 is disposed above the susceptor 39 so as to surround the periphery of the wafer W attracted and held by the electrostatic chuck 49. The focus ring 51 is exposed to the processing space S and converges the plasma toward the surface of the wafer W in the processing space S, thereby improving the efficiency of the RIE processing.

  Further, for example, an annular refrigerant chamber 52 extending in the circumferential direction is provided inside the susceptor 39. A refrigerant having a predetermined temperature, for example, cooling water or galden, is circulated and supplied from the chiller unit (not shown) to the refrigerant chamber 52 via a refrigerant pipe 53 and is adsorbed and held by the electrostatic chuck 49 according to the temperature of the refrigerant. The processing temperature of the wafer W is controlled.

  A plurality of heat transfer gas supply holes 54 are opened in a portion of the electrostatic chuck 49 where the wafer W is adsorbed and held (hereinafter referred to as “adsorption surface”). The plurality of heat transfer gas supply holes 54 are connected to a heat transfer gas supply unit (not shown) via a heat transfer gas supply line 55, and the heat transfer gas supply unit transfers helium gas as the heat transfer gas. The gas is supplied to the gap between the suction surface and the back surface of the wafer W through the hot gas supply hole 54. The helium gas supplied to the gap between the suction surface and the back surface of the wafer W transfers the heat of the wafer W to the susceptor 39 via the electrostatic chuck 49.

  In addition, a plurality of pusher pins 56 as lift pins that can protrude from the electrostatic chuck 49 are disposed on the attracting surface of the susceptor 39. These pusher pins 56 are connected to a motor (not shown) and a ball screw (not shown), and freely protrude from the suction surface due to the rotational motion of the motor converted into a linear motion by the ball screw. The pusher pin 56 is accommodated in the susceptor 39 when the wafer W is sucked and held on the suction surface in order to perform the RIE process on the surface of the wafer W. When the wafer W subjected to the RIE process is unloaded from the chamber 38, the pusher pin 56 protrudes from the electrostatic chuck 49 and lifts the wafer W away from the susceptor 39.

  A gas introduction shower head 57 is disposed on the ceiling of the chamber 38 (reaction chamber 42) so as to face the susceptor 39. An upper high frequency power source 59 is connected to the gas introduction shower head 57 via a matching unit 58, and the upper high frequency power source 59 supplies predetermined high frequency power to the gas introduction shower head 57. Functions as an electrode. The function of the matching unit 58 is the same as the function of the matching unit 47 described above.

  The gas introduction shower head 57 includes a ceiling electrode plate 61 having a large number of gas holes 60 and an electrode support 62 that detachably supports the ceiling electrode plate 61. In addition, a buffer chamber 63 is provided inside the electrode support 62, and a processing gas introduction pipe 64 is connected to the buffer chamber 63. The gas introduction shower head 57 supplies the processing gas supplied from the processing gas introduction pipe 64 to the buffer chamber 63 into the chamber 38 (reaction chamber 42) via the gas hole 60.

  In addition, a loading / unloading port 65 for the wafer W is provided on the side wall of the chamber 38 at a position corresponding to the height of the wafer W lifted upward from the susceptor 39 by the pusher pin 56. A vacuum gate valve 66 for opening and closing 65 is attached.

  In the chamber 38 of the process module 17, as described above, high frequency power is supplied to the susceptor 39 and the gas introduction shower head 57 and high frequency power is applied to the processing space S between the susceptor 39 and the gas introduction shower head 57. As a result, the processing gas supplied from the gas introduction shower head 57 in the processing space S is made into high-density plasma to generate ions and radicals, and the surface of the wafer W is subjected to RIE processing by the ions and the like.

  FIG. 5 is a plan view showing a schematic configuration of the cleaning apparatus in FIG.

  In FIG. 5, the cleaning apparatus 14 includes a cleaning processing unit 67 that performs cleaning processing on a wafer W that has been subjected to RIE processing, and a loading / unloading unit 68 that loads and unloads the wafer W into and from the cleaning processing unit 67.

  The carry-in / out unit 68 includes a cassette mounting table 69 on which the wafer cassette CR delivered from the AGV 16 is placed, and a transfer arm type wafer transfer device that transfers the wafer W between the wafer cassette CR and the cleaning processing unit 67. And a wafer transfer unit 71 having 70. A partition wall 72 is erected between the cassette mounting table 69 and the wafer transfer unit 71, and a port 73 is formed in the partition wall 72 at a position corresponding to each wafer cassette CR mounted on the cassette mounting table 69. A port opening / closing mechanism 74 that opens and closes the port 73 by a shutter or the like is provided on the wafer transfer unit 71 side of the port 73.

  The wafer transfer device 70 is movable in the horizontal direction and the vertical direction, and is rotatable in a horizontal plane. The wafer transfer device 70 transfers the wafer W from the carry-in / out unit 68 to the cleaning processing unit 67 and from the cleaning processing unit 67 to the carry-in / out unit 68.

  The cleaning processing unit 67 temporarily mounts the wafer W when the wafer W is transferred between the main wafer transfer device 75 which is a transfer arm type transfer means and the main wafer transfer device 75 and the wafer transfer unit 71. A wafer transfer unit 76 to be placed, a substrate cleaning unit 77, 78, 79, 80, and a cleaning liquid storage unit 81 for storing a predetermined cleaning liquid to be sent to the substrate cleaning unit 77, 78, 79, 80 are provided. The main wafer transfer device 75 is movable in the horizontal direction and the vertical direction, and is rotatable in a horizontal plane. The main wafer transfer device 75 can access all of the wafer transfer device 70 and the substrate cleaning units 77, 78, 79, and 80.

  Each of the substrate cleaning units 77, 78, 79, and 80 accommodates the wafer W, and sprays a cleaning liquid such as an alkaline aqueous solution, hydrogen peroxide solution, or sulfated water toward the accommodated wafer W. The cleaning liquid dissolves and removes the resist film formed on the surface of the wafer W, and dissolves and removes the resin protective film formed on the back surface of the wafer W.

  Next, the substrate processing method according to the present embodiment will be described.

  FIG. 6 is a flowchart of the substrate processing method according to the present embodiment.

  In FIG. 6, the AGV 16 first transfers the wafer cassette CR to the coater / developer 11, and the coater / developer 11 takes out the wafer W from the wafer cassette CR by the cassette station 18 and reverses the front and back of the wafer W by the wafer reversing unit. Then, the wafer W is carried into the chamber 23 of the coating unit 22c by the wafer transfer mechanism, and the photocurable resin is coated on the back surface of the wafer W by the coating unit 22c (step S61) (coating step).

  Next, the coater / developer 11 carries the wafer W into the curing unit 82a, and the curing unit 82a performs an exposure process on the photocurable resin applied to the back surface of the wafer W to cure the photocurable resin (step). S62) (curing step). Thereby, a resin protective film is formed on the back surface of the wafer W (step S63) (back surface protective film forming step).

  Next, the coater / developer 11 reverses the front and back with the wafer reversing unit, carries the wafer W into the chamber 23 of the coating unit 22, and applies the resist to the surface of the wafer W with the coating unit 22a (step S64) (coating). Step).

  Next, the coater / developer 11 carries the wafer W coated with the resist into the oven unit, and the oven unit cures the resist coated on the surface of the wafer W by heating (step S65) (curing step).

  Next, the coater / developer 11 carries the wafer W into the exposure device 12 by the interface unit 20, and the exposure device 12 corresponds to a pattern that is reversed with respect to a predetermined mask pattern toward the surface of the wafer W by the ultraviolet irradiation lamp. The resist is subjected to exposure processing by irradiating only the portion to be irradiated with ultraviolet rays (step S66). As a result, the resist having a reversed pattern on the surface of the wafer W is altered and becomes alkali-soluble.

  Next, the coater / developer 11 carries the wafer W whose resist has been subjected to exposure processing by the interface unit 20 into the coater / developer 11 and has an inverted pattern that has been altered from the surface to alkali-soluble by the developing units 82b and 82c. Remove the resist. Thereby, a resist film having a predetermined mask pattern is formed on the surface of the wafer W (step S67).

  Next, the coater / developer 11 stores the wafer W on which the resist film is formed in the wafer cassette CR by the cassette station 18, and further transfers the wafer cassette CR to the AGV 16. The AGV 16 moves from the coater / developer 11 to the etching apparatus 13 and delivers the wafer cassette CR to the transfer system of the etching apparatus 13. The etching apparatus 13 takes out the wafer W from the wafer cassette CR by the transfer system, loads it into the chamber 38 of the process module 17, and sucks and holds the wafer W on the electrostatic chuck 49 of the susceptor 39. Further, the etching apparatus 13 performs RIE processing on the surface of the wafer W by the process module 17 (step S68) (etching step).

  Next, the etching apparatus 13 stores the wafer W that has been subjected to the RIE process by the transfer system in the wafer cassette CR, and further transfers the wafer cassette CR to the AGV 16. The AGV 16 moves from the etching apparatus 13 to the cleaning apparatus 14 and delivers the wafer cassette CR to the carry-in / out section 68 of the cleaning apparatus 14. The cleaning device 14 carries the wafer W from the wafer cassette CR into the cleaning processing unit 67 by the wafer transfer unit 71, and carries the wafer W into the substrate cleaning unit 77 or the like by the main wafer transfer device 75, and the substrate cleaning unit 77 or the like. The resist film formed on the surface of the wafer W is dissolved and removed, and the resin protective film formed on the back surface of the wafer W is dissolved and removed (step S69) (cleaning step, protective film removing step). End the process.

  According to the process of FIG. 6, before the RIE process is performed on the front surface of the wafer W, the photocurable resin applied on the back surface of the wafer W is subjected to an exposure process by ultraviolet irradiation to form a resin protective film. Since the resin protective film is removed from the back surface of the wafer W after the RIE process is performed on the surface of the wafer W, the electrostatic chuck 49 comes into contact with the resin protective film formed on the back surface of the wafer W. Therefore, it is possible to prevent the back surface of the wafer W from being scratched when the wafer W is attracted to the electrostatic chuck 49, and the adhesion between the wafer W and the electrostatic chuck 49 is improved. Temperature controllability can be improved.

  Further, according to the process of FIG. 6, after a resin protective film is formed on the back surface of the wafer W and before the RIE process is performed on the surface of the wafer W, a resist having a predetermined mask pattern is formed on the surface of the wafer W. Since the film is formed, the resin protective film and the resist film can be formed separately, so that the resin protective film and the resist film can be formed stably. Further, when the resist film is formed by exposing the front surface of the wafer W, the back surface of the wafer W is supported by the pin-shaped protrusions of the mounting table in the exposure machine 12. Therefore, the wafer W can be stably supported and exposure can be performed stably. Further, when the wafer W is placed on the placing table of the oven unit, the placing table and the resin protective film on the back surface of the wafer W come into contact with each other. Therefore, even in the oven unit, it is possible to prevent the back surface of the wafer W from being scratched and to improve the adhesion between the wafer W and the mounting table.

  Moreover, according to the process of FIG. 6, since the resin protective film is formed by the spin coat process (coating process), the resin protective film can be easily formed.

  In the process of FIG. 6 described above, the resist film is formed on the front surface of the wafer W after the resin protective film is formed on the back surface of the wafer W. However, before the resin protective film is formed on the back surface of the wafer W, A resist film may be formed on the surface. Also by this, since formation of the resin protective film and formation of the resist film can be performed separately, the resin protective film and the resist film can be formed stably.

  In the process of FIG. 6, the resist film on the front surface of the wafer W and the resin protective film on the back surface of the wafer W are dissolved and removed by the cleaning liquid. However, the method for removing the resin protective film is not limited to this. An ashing process using radicals or the like may be used.

  In addition, the processing station 19 of the coater / developer 11 does not have to include a wafer reversing unit. In this case, the coating unit in addition to the resist discharge mechanism 26, the lower surface of the wafer W rotating in the horizontal plane from the lower surface of the wafer W. It is preferable to have a nozzle that sprays a photocurable resin toward the surface. Since the photocurable resin has adhesiveness, it adheres to the back surface of the wafer W and further spreads uniformly on the back surface of the wafer W by centrifugal force.

  Further, instead of forming the resin protective film on the back surface of the wafer W by the spin coating process described above, the resin protective film may be formed by attaching a resin sheet to the back surface of the wafer W.

  Next, a substrate processing system for executing the substrate processing method according to the second embodiment of the present invention will be described.

  This embodiment is basically the same in configuration and operation as the first embodiment described above, and part of the configuration of the substrate processing system and part of the process of the substrate processing method are described above. Only the embodiment is different. Therefore, the description of the same configuration and process is omitted, and only the operation different from the first embodiment will be described below.

  FIG. 7 is a diagram showing a schematic configuration of a substrate processing system for executing the substrate processing method according to the present embodiment.

  In FIG. 7, a substrate processing system 83 includes a CVD (Chemical Vapor Deposition) device 84, a coater / developer 11, an etching device 13, a cleaning device 14, an ashing device 85, a CVD device 84, a coater / developer 11, A guide rail 15 disposed in parallel to the etching device 13, the cleaning device 14, and the ashing device 85, an AGV 16, and an exposure machine 12 disposed adjacent to the coater / developer 11 are provided.

  The CVD apparatus 84 includes a transport system for transporting the wafer W and a plurality of process modules 86 to be described later that form a CF-based protective film on the back surface of the wafer W by a CVD process.

  The ashing device 85 includes a transport system that transports the wafer W and a plurality of process modules that perform an ashing process on the back surface of the wafer W. The process module in the ashing device 85 has the same configuration as the process module 17 in the etching device 13.

  The AGV 16 conveys the wafer cassette CR in the order of the CVD device 84, the coater / developer 11, the etching device 13, the cleaning device 14, and the ashing device 85.

  FIG. 8 is a cross-sectional view showing a schematic configuration of a process module of the CVD apparatus in FIG.

  In FIG. 8, the process module 86 includes a chamber 87 as a housing-like storage chamber for storing a wafer W, a wafer adsorption portion 89 disposed on a ceiling portion 88 of the chamber 87, and a bottom surface portion 90 of the chamber 87. An electrode 91 is disposed so as to face the wafer adsorption unit 89 and is spaced apart from the wafer adsorption unit 89 by a predetermined distance, and an exhaust pipe 92 that exhausts gas in the chamber 87 to the outside. .

  The wafer suction portion 89 is a cylindrical protrusion, and has a plurality of vacuum suction holes (not shown) opened on the bottom surface. The wafer W carried into the chamber 87 is vacuum-sucked by a plurality of vacuum suction holes of the wafer suction part 89 and is held on the bottom surface of the wafer suction part 89. Further, the wafer adsorbing portion 89 has a buffer film 93 made of a heat resistant resin, for example, polyimide, on the lower surface. Therefore, since the surface of the wafer W comes into contact with the bottom surface of the wafer suction portion 89 via the buffer film 93, the shape of the wiring grooves and via holes formed on the surface of the wafer W is not broken. In addition, the wafer suction unit 89 includes a heater (not shown), and maintains the temperature of the wafer W at a predetermined temperature while the protective film is formed on the back surface of the wafer W.

  The electrode 91 is made of a table-like conductive member, and has a plurality of gas ejection holes (not shown) on the surface (upper surface) facing the wafer adsorption portion 89. In addition, a high frequency power supply 94 is connected to the electrode 91 via a matching unit 95, and the high frequency power supply 94 supplies predetermined high frequency power to the electrode 91. As a result, the electrode 91 applies high-frequency power to the processing space S ′ sandwiched between the wafer suction portion 89 and the electrode 91. The matching unit 95 reduces the reflection of the high frequency power from the electrode 91 to maximize the supply efficiency of the high frequency power to the electrode 91.

  In addition, a loading / unloading port 96 for the wafer W is provided on the side wall of the chamber 87 at a position corresponding to the wafer W sucked by the wafer sucking unit 89, and a vacuum gate valve that opens and closes the loading / unloading port 96. 97 is attached.

  In the process module 86, a protective film is formed on the back surface of the wafer W by a CVD process. Specifically, when a deposition process gas, for example, a CF-based gas is supplied from the plurality of gas ejection holes in the electrode 91 to the processing space S ′ and a high-frequency power is applied to the processing space S ′, the CF-based gas is supplied. Radicals and ions are generated from the gas, and the radicals and the like adhere to and deposit on the back surface of the wafer W adsorbed on the wafer adsorbing portion 89 to form a CF-based protective film. At this time, surplus radicals and the like are discharged to the outside through the exhaust pipe 92.

  The thickness of the protective film formed by the process module 86 may be 10 μm or less, and preferably about 1 μm. The type of protective film to be formed is not limited to the CF-based protective film, and may be a protective film made of amorphous carbon.

Further, in the process module of the ashing device 85, when the wafer W having the CF-based protective film formed on the back surface is loaded into the chamber 38 and supported by the pusher pin 56, oxygen (O ₂ ) is supplied from the gas introduction shower head 57. Gas is introduced into the processing space S. At this time, the pusher pins 56 support the wafer W while lifting it upward from the susceptor 39. Therefore, there is also a space below the back surface of the wafer W.

  Further, when high frequency power is supplied to the susceptor 39 and the gas introduction shower head 57 and high frequency power is applied to the processing space S between the susceptor 39 and the gas introduction shower head 57, plasma is generated from oxygen gas in the processing space S. Oxygen radicals are generated. At this time, oxygen radicals also enter the space below the back surface of the wafer W, and the oxygen radicals decompose and remove the CF-based protective film on the back surface of the wafer W (ashing process).

  In the above process module, the CF-based protective film is removed by oxygen radicals. However, fluorine radicals may be generated in the processing space S, and the CF-based protective film on the back surface of the wafer W may be decomposed and removed by the fluorine radicals. Alternatively, ozone gas may be supplied to the processing space S, and the CF-based protective film may be decomposed and removed by the ozone gas.

  Next, the substrate processing method according to the present embodiment will be described.

  FIG. 9 is a flowchart of the substrate processing method according to the present embodiment.

  In FIG. 9, first, the AGV 16 delivers the wafer cassette CR to the CVD apparatus 84, and the CVD apparatus 84 carries the wafer W from the wafer cassette CR into the chamber 87 of the process module 86 by the transfer system. A CF-based protective film is formed on the back surface (step S91) (back surface protective film forming step).

  Next, the CVD apparatus 84 stores the wafer W on which the CF-based protective film is formed in the wafer cassette CR by the transfer system, and further transfers the wafer cassette CR to the AGV 16. The AGV 16 moves from the CVD apparatus 84 to the coater / developer 11 and transfers the wafer cassette CR to the coater / developer 11. The coater / developer 11 takes out the wafer W from the wafer cassette CR by the cassette station 18, loads the wafer W into the chamber 23 of the coating unit 22 a by the wafer transfer mechanism, and coats the resist on the surface of the wafer W by the resist discharge mechanism 26. (Step S92).

  Next, the coater / developer 11 carries the wafer W coated with the resist into the oven unit, and the oven unit cures the resist coated on the surface of the wafer W by heating (step S93) (curing step).

  Next, the coater / developer 11 carries the wafer W into the exposure device 12 by the interface unit 20, and the exposure device 12 corresponds to a pattern that is reversed with respect to a predetermined mask pattern toward the surface of the wafer W by the ultraviolet irradiation lamp. The resist is subjected to exposure processing by irradiating only the portion to be irradiated with ultraviolet rays (step S94). As a result, the resist with the inverted pattern is altered and becomes alkali-soluble.

  Next, the coater / developer 11 carries the wafer W whose resist has been subjected to exposure processing by the interface unit 20 into the coater / developer 11 and has an inverted pattern that has been altered from the surface to alkali-soluble by the developing units 82b and 82c. Remove the resist. Thereby, a resist film having a predetermined mask pattern is formed on the surface of the wafer W (step S95).

  Next, the coater / developer 11 stores the wafer W on which the resist film is formed in the wafer cassette CR by the cassette station 18, and further transfers the wafer cassette CR to the AGV 16. The AGV 16 moves from the coater / developer 11 to the etching apparatus 13 and delivers the wafer cassette CR to the transfer system of the etching apparatus 13. The etching apparatus 13 takes out the wafer W from the wafer cassette CR by the transfer system, loads it into the chamber 38 of the process module 17, and sucks and holds the wafer W on the electrostatic chuck 49 of the susceptor 39. Further, the etching apparatus 13 performs RIE processing on the surface of the wafer W by the process module 17 (step S96) (etching step).

  Next, the etching apparatus 13 stores the wafer W that has been subjected to the RIE process by the transfer system in the wafer cassette CR, and further transfers the wafer cassette CR to the AGV 16. The AGV 16 moves from the etching apparatus 13 to the cleaning apparatus 14 and delivers the wafer cassette CR to the carry-in / out section 68 of the cleaning apparatus 14. The cleaning device 14 carries the wafer W from the wafer cassette CR into the cleaning processing unit 67 by the wafer transfer unit 71, and carries the wafer W into the substrate cleaning unit 77 or the like by the main wafer transfer device 75, and the substrate cleaning unit 77 or the like. The resist film formed on the surface of the wafer W is dissolved and removed (step S97) (cleaning step).

  Next, the cleaning device 14 stores the wafer W from which the resist film has been removed by the wafer transfer unit 71 in the wafer cassette CR, and further transfers the wafer cassette CR to the AGV 16. The AGV 16 moves from the cleaning device 14 to the ashing device 85 and delivers the wafer cassette CR to the transfer system of the ashing device 85. The ashing device 85 takes out the wafer W from the wafer cassette CR by the transfer system and loads it into the chamber 38 of the process module, and further disassembles and removes the CF-based protective film on the back surface of the wafer W by ashing in the process module ( Step S98) (protective film removal step), this process is terminated.

  According to the process of FIG. 9, before the RIE process is performed on the surface of the wafer W, a CF-based protective film is formed on the back surface of the wafer W, and after the RIE process is performed on the surface of the wafer W, Since the CF-based protective film is removed from the back surface, the electrostatic chuck 49 comes into contact with the CF-based protective film formed on the back surface of the wafer W. Therefore, the same effects as those of the first embodiment can be obtained.

  Further, according to the process of FIG. 9, after a CF protective film is formed on the back surface of the wafer W and before the RIE process is performed on the surface of the wafer W, a predetermined mask pattern is formed on the surface of the wafer W. Since the resist film is formed, the formation of the CF protective film and the resist film can be performed separately. Further, when the resist film is formed, the back surface of the wafer W and the mounting table of the exposure device 12 are formed. A CF-based protective film is interposed between the protrusions. Therefore, the same effects as those of the first embodiment can be obtained.

  In addition, according to the process of FIG. 9, the CF-based protective film is formed by the CVD process, which is a vapor deposition process. Therefore, a CF-based protective film having a stable film thickness can be surely formed. It is possible to reliably prevent the back surface from being scratched.

  In the process of FIG. 9 described above, after the CF-based protective film is formed on the back surface of the wafer W, a resist film is formed on the front surface of the wafer W. However, before the CF-based protective film is formed on the back surface of the wafer W, A resist film may be formed on the surface of W. Also by this, since the formation of the CF protective film and the formation of the resist film can be performed separately, the CF protective film and the resist film can be formed stably.

  In the substrate processing system 83 described above, the CVD apparatus 84 forms the CF-based protective film by the CVD process. However, the protective film is not limited to the CF-based protective film, and a protective film made of a photocurable resin may be formed. Good. Further, the method for forming the protective film is not limited to the CVD process, and any process using vapor deposition may be used. For example, PVD (Physical Vapor Deposition) process may be used.

  In each of the above-described embodiments, the substrate subjected to the RIE process is not limited to a semiconductor wafer, but various substrates used for LCD (Liquid Crystal Display), FPD (Flat Panel Display), etc., photomasks, CD substrates, printed boards, etc. It may be.

  Further, the workable resin in each of the above-described embodiments is a positive type, but may be a negative type.

  Another object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus, and the computer of the system or apparatus (or CPU, MPU, or the like). Is also achieved by reading and executing the program code stored in the storage medium.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code and the storage medium storing the program code constitute the present invention. .

  Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM, and a DVD. An optical disc such as RW or DVD + RW, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used. Alternatively, the program code may be downloaded via a network.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (Operating System) running on the computer based on the instruction of the program code. Includes a case where the functions of the above-described embodiments are realized by performing part or all of the actual processing.

  Furthermore, after the program code read from the storage medium is written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the expanded function is based on the instruction of the program code. This includes a case where a CPU or the like provided on the expansion board or the expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

It is a figure showing the schematic structure of the substrate processing system which performs the substrate processing method concerning a 1st embodiment of the present invention. It is a front view which shows schematic structure of the coater / developer in FIG. It is sectional drawing which shows schematic structure of the application | coating unit in FIG. It is sectional drawing which shows schematic structure of the process module of the etching apparatus in FIG. It is a top view which shows schematic structure of the washing | cleaning apparatus in FIG. It is a flowchart of the substrate processing method which concerns on this Embodiment. It is a figure which shows schematic structure of the substrate processing system which performs the substrate processing method which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows schematic structure of the process module of the CVD apparatus in FIG. It is a flowchart of the substrate processing method which concerns on this Embodiment.

Explanation of symbols

W Wafer 10 Substrate Processing System 11 Coater / Developer 12 Exposure Machine 13 Etching Device 14 Cleaning Device 22a, 22c Coating Unit 82a Curing Unit 49 Electrostatic Chuck 77, 78, 79, 80 Substrate Cleaning Unit 84 CVD Device 85 Ashing Device

Claims (6)

A substrate processing method in a substrate processing system comprising at least an etching apparatus for performing plasma etching on a substrate, the etching apparatus having an electrostatic chuck for electrostatically attracting the substrate, wherein the electrostatic chuck is in contact with the back surface of the substrate. There,
A coating step of applying a photocurable resin on the back surface of the substrate,
A curing step that form a protective film a photocurable resin applied on the back surface of the substrate is cured by exposure,
An inversion step of inverting the front and back surfaces of the substrate;
A resist film forming step of forming a resist film having a predetermined mask pattern on the surface of the substrate;
An etching step of performing the plasma etching process on the surface of the substrate;
The substrate processing method characterized by having a cleaning step of removing the protective film. A substrate processing method in a substrate processing system comprising at least an etching apparatus for performing plasma etching on a substrate, the etching apparatus having an electrostatic chuck for electrostatically attracting the substrate, wherein the electrostatic chuck is in contact with the back surface of the substrate. There,
A resist film forming step of forming a resist film having a predetermined mask pattern on the surface of the substrate ;
A first inversion step of inverting the front and back surfaces of the substrate;
An application step of applying a photocurable resin to the back surface of the substrate;
A curing step of curing a photocurable resin applied to the back surface of the substrate by exposure to form a protective film;
A second inversion step of inverting the front and back surfaces of the substrate;
An etching step of performing the plasma etching process on the surface of the substrate;
Washing step and, board processing how to further comprising a removing the protective film. 3. The substrate processing method according to claim 1, wherein the light used for the exposure is ultraviolet light. The electrostatic chuck is Y ₂ O ₃ , Al ₂ O ₃ Or SiO ₂ The substrate processing method according to claim 1, wherein the substrate processing method is formed of any one of the above. A substrate processing method in a substrate processing system comprising at least an etching apparatus for performing plasma etching on a substrate, the etching apparatus having an electrostatic chuck for electrostatically attracting the substrate, wherein the electrostatic chuck is in contact with the back surface of the substrate. A computer-readable storage medium for storing a program to be executed by a computer,
The substrate processing method includes:
A coating step of applying a photocurable resin on the back surface of the substrate,
A curing step that form a protective layer a curable resin applied to the back surface of the substrate is cured by exposure,
An inversion step of inverting the front and back surfaces of the substrate;
A resist film forming step of forming a resist film having a predetermined mask pattern on the surface of the substrate;
An etching step of performing the plasma etching process on the surface of the substrate;
Storage medium characterized by having, a cleaning step of removing the protective film. A substrate processing method in a substrate processing system comprising at least an etching apparatus for performing plasma etching on a substrate, the etching apparatus having an electrostatic chuck for electrostatically attracting the substrate, wherein the electrostatic chuck is in contact with the back surface of the substrate. A computer-readable storage medium for storing a program to be executed by a computer,
The substrate processing method includes:
A resist film forming step of forming a resist film having a predetermined mask pattern on the surface of the substrate;
A first inversion step of inverting the front and back surfaces of the substrate;
An application step of applying a photocurable resin to the back surface of the substrate;
A curing step of curing the curable resin applied to the back surface of the substrate by exposure to form a protective film;
A second inversion step of inverting the front and back surfaces of the substrate;
An etching step of performing the plasma etching process on the surface of the substrate;
And a cleaning step for removing the protective film.

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