JP4286545B2 - Substrate processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate processing method for removing a resist film from a substrate having a resist film modified by ion implantation.
[0002]
[Prior art]
For example, in the manufacturing process of a semiconductor device, ion implantation technology is used to implant predetermined ions into a semiconductor wafer or various films formed on the surface of the semiconductor wafer, thereby changing the surface characteristics. For example, a pn junction can be formed by implanting arsenic (As), phosphorus (P), boron (B), or the like into a semiconductor wafer (silicon substrate).
[0003]
  Such an ion implantation process is a resist having a predetermined circuit pattern on the surface of a semiconductor wafer or the like.filmTheAs a maskThis is often performed after the formation, and in this case, the resist that is no longer needed after the ion implantation process.filmNeed to be removed. Resist with low ion implantationfilmAs a method for removing this, wet etching with a chemical solution and plasma ashing using oxygen plasma discharge are known. In addition, a resist that has been ion-implanted at a high concentrationfilmTherefore, a method of performing wet etching after plasma ashing or the like is used as this removal method (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-37780 (paragraphs 21 to 29, FIGS. 2 to 4)
[0005]
[Problems to be solved by the invention]
  However, there is a problem that plasma ashing damages portions other than unnecessary resist films, that is, ion-implanted underlying substrates and films.
  The present invention has been made in view of such circumstances, and resistsfilmIon implantation without damaging the underlying substrate or filmTransformedResistant resistfilmProvide a substrate processing method for removingAimed at.
[0007]
[Means for Solving the Problems]
  According to the present invention,A substrate processing method for removing a resist film from a substrate having a modified resist film by implanting predetermined ions,
  AboveA substrate having a resist film is treated with a treatment gas containing ozone and water vapor,A step of denaturing a portion of the resist film where ions are not retained, to be water-soluble,
  The substrate treated with the processing gas is washed with water, and the resist film is modified to be water-soluble by the processing gas.ExcludingThe process of leaving,
  The washed substratePredeterminedTreated with chemicals that dissolve ionsAnd dissolve the ions in the remaining resist filmProcess,
  The substrate treated with the chemical solution is washed with a predetermined cleaning solution from the substrate.RemainRemoving the resist film;
  There is provided a substrate processing method characterized by comprising:
[0008]
According to such a substrate processing method, it is possible to remove the resist film that is hardly peelable by the ion implantation process without damaging the underlying layer, so that productivity and product quality are improved. .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a semiconductor wafer (silicon wafer) will be taken as a substrate, and embodiments of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is an explanatory diagram showing a schematic configuration of a wafer processing system. This wafer processing system is composed of a CVD apparatus 101, a resist coating / developing apparatus 102, an exposure apparatus 103, an ion implantation apparatus 104, and a film removal apparatus 100. Thus, the wafer W can be transferred.
[0010]
The CVD apparatus 101 is used for forming an insulating film, a stopper film, and the like on the wafer W by a chemical vapor deposition (CVD) method. Instead of the CVD apparatus 101, an SOD (Spin On Dielectric) apparatus that applies a chemical solution to the wafer W to form an insulating film or the like can also be used.
[0011]
The resist coating / developing apparatus 102 is used to form a resist film used as a mask. Although the detailed structure of the resist coating / developing apparatus 102 is not shown, the resist coating / developing apparatus 102 includes a resist coating processing unit that coats a resist solution on the wafer W to form a resist film, and an antireflection film on the wafer W. A BARC coating processing unit for forming (BARC), a development processing unit for developing a resist film exposed in a predetermined pattern in the exposure apparatus 103, a wafer W on which a resist film is formed, and a wafer subjected to exposure processing W, a wafer W that has been subjected to development processing, and a wafer W on which an antireflection film has been formed are each thermally processed.
[0012]
The exposure apparatus 103 is used for exposing a predetermined circuit pattern to the wafer W on which a resist film is formed. In the ion implantation apparatus 104, ion implantation processing of As, P, B, or the like is performed on the wafer W or an insulating film formed on the wafer W according to the processing stage of the wafer W. The film removing apparatus 100 is used to remove a resist film (mask) and the like that are not required in the manufacturing process of a semiconductor device from the wafer W. In this description, a resist film cured by ion implantation (hereinafter, “ It is used to remove the resist cured film). The resist cured film has a portion hardened by the implanted ions and a portion through which the implanted ions pass or does not reach the implanted ions.
[0013]
Next, the configuration of the film removal apparatus 100 will be described in detail. 2 is a schematic plan view of the film removing apparatus 100, FIG. 3 is a schematic front view thereof, and FIG. 4 is a schematic rear view thereof. In the film removing apparatus 100, the carrier containing the wafer W is carried in from another processing apparatus or the like, and conversely, the carrier containing the wafer W that has been processed in the film removing apparatus 100 is transferred to the processing apparatus or the like that performs the next processing. Between the carrier station 4 for carrying out, the treatment station 2 having a plurality of treatment units for performing the removal processing of the resist cured film, the water washing / drying treatment of the wafer W, and the like, and between the treatment station 2 and the carrier station 4 A transfer station 3 that transfers the wafer W and a chemical station 5 that manufactures, prepares, and stores chemicals, pure water, and gas used in the processing station 2 are provided.
[0014]
Inside the carrier C, the wafers W are accommodated at a constant interval in the vertical direction (Z direction) in a substantially horizontal posture. Such loading / unloading of the wafer W with respect to the carrier C is performed through one side surface of the carrier C, and this side surface is not shown in FIG. 2 (the state in which the lid body 10a is removed in FIGS. 3 and 4). Can be opened and closed freely.
[0015]
As shown in FIG. 2, the carrier station 4 has mounting tables 6 on which carriers C can be mounted at three locations along the Y direction in the figure, and the side of the carrier C provided with a lid is the carrier station. 4 and the transfer station 3 are placed on the mounting table 6 so as to face the boundary wall 8a side. A window portion 9a is formed at a position corresponding to the place where the carrier C is placed on the boundary wall 8a, and a shutter 10 for opening and closing the window portion 9a is provided on the transfer station 3 side of each window portion 9a. The shutter 10 has a gripping means (not shown) for gripping the lid 10a of the carrier C. As shown in FIGS. 3 and 4, the shutter 10 holds the lid 10a toward the transfer station 3 side. The lid 10a can be retracted.
[0016]
The wafer transfer device 7 provided in the transfer station 3 has a wafer transfer pick 7 a that can hold the wafer W. The wafer transfer device 7 is movable in the Y direction along a guide 11 (see FIGS. 3 and 4) provided on the floor of the transfer station 3 so as to extend in the Y direction. The wafer transfer pick 7a is slidable in the X direction, can be moved up and down in the Z direction, and is rotatable (θ rotation) in the XY plane.
[0017]
With such a structure, in a state where the shutter 10 is retracted so that the inside of the carrier C and the transfer station 3 communicate with each other via the window portion 9a, the wafer transfer pick 7a is all mounted on the mounting table 6. The wafer W can be accessed from the carrier C and can be unloaded from the carrier C. Conversely, the wafer W can be loaded to any position on the carrier C. .
[0018]
The processing station 2 has two wafer placement units (TRS) 13 a and 13 b on the transfer station 3 side. For example, the wafer placement unit (TRS) 13 b receives a wafer W from the transfer station 3. The wafer mounting unit (TRS) 13a is used for mounting the wafer W when returning the wafer W that has undergone predetermined processing in the processing station 2 to the transfer station 3. Used. As will be described later, since clean air is downflowed from the fan filter unit (FFU) 25 in the processing station 2, the wafer W that has been processed in the processing station 2 is transferred to the upper wafer mounting unit (TRS) 13a. As a result, the contamination of the wafer W is suppressed.
[0019]
On the boundary wall 8b between the transfer station 3 and the processing station 2, a window portion 9b is provided at a portion corresponding to the position of the wafer placement units (TRS) 13a and 13b. The wafer transfer pick 7a can access the wafer mounting units (TRS) 13a and 13b through the window 9b, and transfers the wafer W between the carrier C and the wafer mounting units (TRS) 13a and 13b. To do.
[0020]
On the back side of the processing station 2, film modification processing units (VOS) 15 a to 15 h for performing a modification treatment of the resist cured film with these molecules of the processing gas containing ozone and water vapor are arranged. Here, “modification of the resist cured film” means that the resist cured film changes to water-soluble in a state in which a portion where the implanted ions do not exist (an uncured portion) remains on the wafer W; In FIG. 5, when the implanted ions are removed from the portion hardened by the implanted ions and then treated with a processing gas, this portion changes to water-soluble while remaining on the wafer W. If there is a polymer residue that is not ion-implanted in the wafer W, this polymer residue is also denatured to be water-soluble by treatment with a treatment gas.
[0021]
The membrane modification processing units (VOS) 15a to 15d and the membrane modification processing units (VOS) 15e to 15h have a substantially symmetrical structure with respect to the boundary wall 22b. As a result, the main wafer transfer device 14 can have a simple structure that does not require a mechanism for moving in the X direction, and the wafer transfer arm 14a can easily access the film modification processing units (VOS) 15a to 15h. It has become.
[0022]
Here, the film modification processing unit (VOS) 15a is taken as an example, and the structure thereof will be described in detail with reference to the schematic cross-sectional view shown in FIG. The film modification processing unit (VOS) 15a has a hermetically sealed chamber 30 that accommodates the wafer W, and the chamber 30 includes a fixed lower container 41a and a lid body 41b that covers the upper surface of the lower container 41a. The lid 41b can be moved up and down by a cylinder 43 fixed to a frame 42 of a membrane modification unit (VOS) 15a.
[0023]
An O-ring 51 is disposed on the upper surface of the rising portion at the periphery of the lower container 41a. When the cylinder 43 is driven to lower the lid 41b, the peripheral edge of the back surface of the lid 41b comes into contact with the upper surface of the raised portion of the peripheral edge of the lower container 41a, and the O-ring 51 is compressed and sealed in the chamber 30. A processing space is formed.
[0024]
The lower container 41 a is provided with a stage 33 on which the wafer W is placed. Proximity pins 44 that support the wafer W are provided at a plurality of locations on the surface of the stage 33. The height of the proximity pins 44 is set to a height at which the back surface of the wafer W does not come into contact with the condensed droplets when condensation occurs on the surface of the stage 33, for example, 1 mm to 3 mm. This prevents watermarks and particles from adhering to the back surface of the wafer W, and the quality of the wafer W is kept high.
[0025]
A heater 45a is embedded in the stage 33 and a heater 45b is embedded in the lid body 41b, respectively, so that the stage 33 and the lid body 41b can be respectively held at a predetermined temperature. Thereby, the temperature of the wafer W is kept constant. In addition, it is also possible to perform the processing by providing a temperature gradient in the processing space by changing the temperature of the stage 33 and the lid 41b.
[0026]
On the back surface of the lid 41b, claw members 46 for holding the wafer W are provided, for example, at three locations (only two locations are shown in FIG. 5). The wafer transfer arm 14 a delivers the wafer W to the claw member 46. When the lid 41 b is lowered while the claw member 46 holds the wafer W, the wafer W is transferred to the proximity pins 44 provided on the stage 33 during the lowering.
[0027]
The chamber 30 has a gas inlet 34a for introducing a processing gas containing ozone and water vapor therein and a gas outlet 34b for exhausting the processing gas to the outside so that the processing gas flows in a substantially horizontal direction inside the chamber 30. The container 41a is provided. The processing gas supply device 16 is connected to the gas inlet 34a, and the exhaust device 32 is connected to the gas outlet 34b. In FIG. 5, the height positions of the gas inlet 34 a and the gas outlet 34 b are shown below the height of the wafer W placed on the proximity pin 44, but the gas inlet 34 a and the gas outlet 34b may be provided at a position higher than this.
[0028]
The processing of the wafer W with the processing gas is preferably performed while maintaining the interior of the chamber 30 at a constant positive pressure. Therefore, the sealing between the lower container 41a and the lid body 41b depends on the pressing force by the cylinder 43 so that the processing gas does not flow out from the inside of the chamber 30 between the lower container 41a and the lid body 41b. In addition, the protrusions 47 a and 47 b provided on the end surfaces of the lower container 41 a and the lid body 41 b are fastened by the lock mechanism 35.
[0029]
The protrusions 47a and 47b do not surround the entire circumference of the lower container 41a and the lid body 41b, respectively. For example, the protrusions 47a and 47b are provided at four positions at equal intervals in the vertical direction between the adjacent objects. Is formed with a gap 49 (see the right side of FIG. 5). The lock mechanism 35 holds the protrusions 47a and 47b between the rollers 59a and 59b to bring the lower container 41a and the lid 41b into close contact with each other. However, when the rollers 59a and 59b are moved to the position of the gap 49, the lid 41b can be moved up and down freely.
[0030]
On the front side of the processing station 2, the wafer W that has been processed in the film modification processing units (VOS) 15 a to 15 h is treated with pure water, so that the portion of the resist cured film that has become water-soluble is removed from the wafer W. In addition, chemical cleaning units (CNU) 12a to 12d that can remove implanted ions from the cured resist film with a chemical and further wash and dry the wafer W are disposed. In addition, a main wafer transfer device 14 for transferring the wafer W in the process station 2 is provided at a substantially central portion of the process station 2. The cleaning units (CNU) 12a and 12b and the cleaning units (CNU) 12c and 12d have a substantially symmetrical structure with respect to the boundary wall 22a.
[0031]
FIG. 6 is a cross-sectional view showing a schematic structure of the cleaning processing unit (CNU) 12a. An annular cup (CP) is arranged at the center of the cleaning unit (CNU) 12a, and a spin chuck 71 is arranged inside the cup (CP). The spin chuck 71 is rotationally driven by a drive motor 72 in a state where the wafer W is fixedly held by vacuum suction. A drain 73 is provided at the bottom of the cup (CP) to discharge chemicals, cleaning liquid, and pure water.
[0032]
The drive motor 72 is disposed in an opening 74a provided in the unit bottom plate 74 so as to be movable up and down, and is coupled to a lift drive mechanism 76 and a lift guide 77 made of, for example, an air cylinder via a cap-like flange member 75 made of, for example, aluminum. Has been. A cylindrical cooling jacket 78 made of, for example, SUS is attached to the side surface of the drive motor 72, and the flange member 75 is attached so as to cover the upper half of the cooling jacket 78.
[0033]
When supplying a chemical solution or the like to the wafer W, the lower end 75a of the flange member 75 is in close contact with the unit bottom plate 74 near the periphery of the opening 74a, thereby sealing the inside of the unit. When the wafer W is transferred between the spin chuck 71 and the wafer transfer arm 14a, the elevating drive mechanism 76 lifts the drive motor 72 and the spin chuck 71 upward so that the lower end of the flange member 75 is removed from the unit bottom plate 74. It comes to float.
[0034]
The cleaning unit (CNU) 12 a supplies a chemical solution nozzle (hereinafter referred to as “ion-dissolved chemical solution”) for dissolving and removing implanted ions from the resist cured film on the surface of the wafer W held by the spin chuck 71. 81, a pure water nozzle (not shown) for supplying pure water to the surface of the wafer W, a cleaning liquid nozzle (not shown) for supplying a predetermined cleaning liquid (for example, APM chemical liquid) to the wafer W, A gas nozzle (not shown) for injecting dry gas.
[0035]
The chemical nozzle 81 is held by the scan arm 82. The scan arm 82 is attached to the upper end of a vertical support member 85 that can move horizontally on a guide rail 84 laid in the X direction on the unit bottom plate 74, and is connected to the vertical support member 85 by an X-axis drive mechanism 96. It moves together in the X direction. Further, the scan arm 82 can be expanded and contracted in the X direction, and can be moved in the vertical direction (Z direction) by the Z-axis drive mechanism 97. Thus, the chemical nozzle 81 is movable between a predetermined position above the wafer W and a predetermined position outside the cup (CP). Other nozzles such as a pure water nozzle are also configured to be movable in the same manner as the chemical liquid nozzle 81.
[0036]
The main wafer transfer device 14 has a wafer transfer arm 14a for transferring the wafer W. The main wafer transfer device 14 is rotatable around the Z axis. Further, the wafer transfer arm 14a can move back and forth in the horizontal direction and can move up and down in the Z direction. With such a structure, the main wafer transfer device 14 can access each unit provided in the processing station 2 and transfers the wafer W between these units. A fan filter unit (FFU) 25 that blows clean air into the processing station 2 is provided above the processing station 2.
[0037]
The chemical station 5 includes a processing gas supply device 16 that adjusts a processing gas containing ozone and water vapor and supplies it to the film modification processing units (VOS) 15a to 15h, and a chemical solution used in the cleaning processing units (CNU) 12a to 12d. And a pure water supply device 18 for supplying pure water to the cleaning processing units (CNU) 12a to 12d are provided.
[0038]
The processing gas supply device 16 includes, for example, an ozone generator that ozonizes oxygen gas, a nitrogen gas that supplies nitrogen gas for diluting ozone, and nitrogen gas for purging the inside of the chamber 30 after the resist cured film is modified. A line, a water vapor generator that vaporizes pure water to generate water vapor, and a mixer that mixes an ozone / nitrogen mixed gas and water vapor to generate a processing gas. In the ozone generator, ozone / nitrogen mixed gas can be generated by ozonizing oxygen in the air. The chemical station 5 is provided with a gas supply adjusting device (not shown) for controlling the supply of the dry gas to the cleaning processing units (CNU) 12a to 12d. The supply of the dry gas to the gas supply adjusting device is performed using a supply line such as a factory pipe (not shown), for example.
[0039]
Next, the process of removing the cured resist film cured by the ion implantation process using the wafer processing system configured as described above will be described. FIG. 7 is a flowchart showing a resist mask (resist film) removal process, and FIG. 8 is an explanatory view schematically showing a schematic form change of the wafer W. In FIG. 8, the wafer W is described as “Si-sub”.
[0040]
First, the wafer W is carried into the CVD apparatus 101, where an insulating film 61 is formed on the surface of the wafer W (step 1, FIG. 8A). Next, the wafer W on which the insulating film 61 is formed is carried into the resist coating / developing apparatus 102, where a resist film 62 is formed on the insulating film 61 using a resist coating processing unit. Subsequently, the wafer W is transferred to the exposure apparatus 103, where the resist film 62 is exposed with a predetermined pattern. By returning the wafer W to the resist coating / developing apparatus 102 and developing the resist film 62 in the development processing unit, the resist film 62 is patterned (step 2, FIG. 8B).
[0041]
Next, the wafer W is transferred to the ion implantation apparatus 104, where ion implantation processing of a predetermined element is performed (step 3, FIG. 8C). For example, ions of a predetermined element are ion-implanted (dose) into the wafer W at a predetermined speed so that the ions do not remain in the insulating film 61, for example, 10.¹⁵/ Cm²When the implantation is performed as described above, the resist film 62 functions as a stopper, and ions are implanted into the wafer W below the groove portion of the resist film 62 to form a region 64 in which the characteristics of the wafer W are changed. In the resist film 62, the implanted ions 66 remain at a position deeper than a certain height, and the portion is cured. By such an ion implantation process, the resist film 62 becomes a resist cured film 63 having a portion (hereinafter referred to as “ion non-staying portion”) 63a where the implanted ions 66 are not substantially retained and a cured portion 63b.
[0042]
The wafer W that has been subjected to the ion implantation process is transferred to the film removing apparatus 100, where the resist cured film 63 is modified (step 4, FIG. 8 (d)), and washed with water (step 5, FIG. 8 (e)). ), A process of dissolving and removing the implanted ions 66 from the resist cured film 63 (step 6, FIG. 8F) is sequentially performed. Then, when the resist cured film 63 can be completely removed from the wafer W by the APM chemical solution (ammonia-hydrogen peroxide solution) after the processing in step 6, this APM chemical treatment is performed (step 7, FIG. 8 ( g)). However, if the resist cured film 63 cannot be completely removed even if the APM chemical treatment is performed after the process of step 6 (for example, when the dose of ions is large), the resist cured film 63 is modified by the processing gas. The process (step 4) to the process of dissolving and removing the implanted ions 66 (step 6) are repeated until the resist cured film 63 can be completely removed from the wafer W by the APM chemical solution process.
[0043]
Hereinafter, step 4 to step 7 will be described more specifically.
In order to perform the process of step 4 on the wafer W, the wafer W is loaded into a film modification processing unit (VOS) 15a (or any one of 15b to 15h) provided in the film removal apparatus 100. The wafer W is loaded into the film modification processing unit (VOS) 15a as follows. First, the carrier C in which the wafer W having been subjected to the ion implantation process is accommodated is placed on the placing table 6 by an operator or an automatic transfer device. Next, the window 9a is opened by retracting the cover 10a and the shutter 10 of the carrier C toward the transfer station 3, and then a single wafer W at a predetermined position of the carrier C is placed on the wafer by the wafer transfer pick 7a. Transport to unit (TRS) 13b.
[0044]
Subsequently, the wafer W placed on the wafer placement unit (TRS) 13b is carried into the film modification unit (VOS) 15a (or any one of 15b to 15h) by the wafer transfer arm 14a. The process of loading the wafer W into the film modification unit (VOS) 15a is performed as follows. That is, the lid body 41b of the chamber 30 is first retracted above the lower container 41a, and then the portion of the claw member 46 provided on the lid body 41b that holds the wafer W (the portion that protrudes in the horizontal direction). Then, the wafer transfer arm 14a holding the wafer W is advanced so that the wafer W enters a position slightly higher than that. Next, when the wafer transfer arm 14 a is lowered, the wafer W is transferred to the claw member 46.
[0045]
After retracting the wafer transfer arm 14a from the film modification unit (VOS) 15a, the lid 41b is lowered, the lid 41b is brought into close contact with the lower container 41a, and the lock mechanism 35 is operated to seal the chamber 30. State. The wafer W is transferred from the claw member 46 to the proximity pin 44 while the lid 41b is being lowered.
[0046]
In this way, the process of step 4 is performed on the wafer W carried into the film modification unit (VOS) 15a as follows. The heaters 45a and 45b are heated to maintain the stage 33 and the lid 41b at a predetermined temperature. At this time, for example, if the temperature of the lid 41b is set higher than the temperature of the stage 33, when the processing gas is supplied into the chamber 30, the density of water vapor in the chamber 30 is higher than that on the lid 41b side. Since it becomes higher on the 33 side, water vapor can be efficiently applied to the wafer W.
[0047]
When the stage 33 and the lid 41b are held at a predetermined temperature and the temperature distribution of the wafer W becomes substantially constant, only the ozone / nitrogen mixed gas is first supplied from the processing gas supply device 16 into the chamber 30. The inside of the chamber 30 is purged with an ozone / nitrogen mixed gas and adjusted to have a predetermined positive pressure.
[0048]
Thereafter, a processing gas in which water vapor is mixed with an ozone / nitrogen mixed gas is supplied from the processing gas supply device 16 into the chamber 30. Ozone and water vapor molecules attack the carbon atoms constituting the resist cured film 63 (carbon atoms of the resist material), and mainly change the ion non-staying portion 63a in the resist cured film 63 to be water-soluble. However, in the cured portion 63b, the implanted ions 66 prevent the ozone and water vapor molecules from attacking the resist material, so that they do not easily change to water solubility (FIG. 8D). For this reason, it is necessary to remove the implanted ions 66 from the hardening portion 63b once.
[0049]
In addition, when the polymer residue which is not ion-implanted exists in the wafer W, this polymer residue changes to water solubility. Further, the processing gas does not damage the insulating film 61. The processing of the wafer W with the processing gas is performed, for example, for 3 minutes to 5 minutes. The supply amount of the processing gas to the chamber 30 and the exhaust amount from the chamber 30 are adjusted so that the inside of the chamber 30 has a predetermined positive pressure.
[0050]
When a predetermined processing time has elapsed, supply of the processing gas is stopped, nitrogen gas is supplied into the chamber 30 from the processing gas supply device 16, and the inside of the chamber 30 is purged with nitrogen gas. During the purge process, the ozone / nitrogen mixed gas does not flow back from the exhaust device 32 when the chamber 30 is opened, and the ozone / nitrogen mixed gas is not discharged from the chamber 30. The nitrogen mixed gas is exhausted completely.
[0051]
When the processing in step 4 is completed, the ion non-retaining portion 63a of the resist cured film 63 has changed to water-soluble, but has not been peeled off from the wafer W, and of course, the cured portion 63b has also been peeled off from the wafer W. Not. Therefore, in order to remove the portion of the resist cured film 63 that has changed to water-soluble from the wafer W (including the portion that has changed to water-soluble by the processing gas in the cured portion 63b), the wafer W is removed. The wafer is transferred from the film modification unit (VOS) 15a to the cleaning unit (CNU) 12a (or any one of 12b to 12d), where the process of step 5 is performed on the wafer W.
[0052]
The wafer W is transferred from the film modification unit (VOS) 15a to the cleaning unit (CNU) 12a as follows. After the nitrogen gas purge inside the chamber 30 is finished first, it is confirmed that the internal pressure of the chamber 30 is the same as the external pressure. This is because if the chamber 30 is opened while the internal pressure of the chamber 30 is higher than the atmospheric pressure, the chamber 30 may be damaged. After confirming the internal pressure of the chamber 30, the locking of the lower container 41a and the lid body 41b by the lock mechanism 35 is released, and the lid body 41b is raised. When the lid 41b is raised, the wafer W is held by the claw member 46 and rises together with the lid 41b. The wafer transfer arm 14a is moved into the gap between the lower container 41a and the lid 41b, and the wafer W is transferred from the claw member 46 to the wafer transfer arm 14a.
[0053]
The wafer transfer arm 14a holding the wafer W delivers the wafer W to the spin chuck 71 provided in the cleaning processing unit (CNU) 12a. In this way, the process of step 5 is performed on the wafer W carried into the cleaning processing unit (CNU) 12a. For example, pure water is discharged from the pure water nozzle onto the surface of the wafer W held in a substantially horizontal posture to form a paddle, and after a predetermined time has elapsed, the wafer W is rotated to sprinkle the pure water from the surface of the wafer W. Further, pure water is supplied to the surface of the wafer W while rotating the wafer W. Thus, the water-soluble portion of the resist cured film 63 is removed (FIG. 8E).
[0054]
Next, while the wafer W remains in the cleaning processing unit (CNU) 12a, the process of step 6 is performed on the wafer W, that is, an ion-dissolved chemical solution is supplied to the surface of the wafer W to cure the resist cured film 63. A process of dissolving and removing the implanted ions 66 from the part 63b is performed. For example, a paddle is formed by discharging an ion-dissolved chemical solution from the chemical solution nozzle 81 on the surface of the wafer W held in a substantially horizontal posture by the spin chuck 71, and after a predetermined time has elapsed, the wafer W is rotated to rotate the surface of the wafer W. Shake off the ion-dissolved chemical solution. The ion-dissolved chemical liquid thus shaken off from the wafer W can be recovered and reused. Next, pure water is discharged from the pure water nozzle onto the surface of the wafer W while rotating the wafer W to remove the ion-dissolved chemical solution from the surface of the wafer W (FIG. 8F).
[0055]
When the hardened portion 63b after the implanted ions 66 are dissolved and removed in this manner can be completely removed from the wafer W by the subsequent APM chemical treatment (for example, the dose amount of ions is 10).¹⁵/ Cm²Even if it is above, the wafer W remains in the cleaning processing unit (CNU) 12a, and the wafer W is continuously subjected to the APM chemical processing (step S3). 7). As a result, the entire resist cured film 63 is completely removed from the wafer W (FIG. 8G). After the APM chemical treatment, the wafer W is rinsed with pure water and spin-dried. This spin drying may be performed while supplying a drying gas to the wafer W. Note that the surface of the insulating film 61 may be thinly removed by APM chemical treatment depending on the composition.
[0056]
On the other hand, when the dose amount of ions to the wafer W is large, the hardened portion 63b remaining on the wafer W after the completion of step 6 may not be completely removed by the APM chemical treatment. In such a case, the wafer W is transferred from the cleaning processing unit (CNU) 12a to the film modification processing unit (VOS) 15a (or 15b to 15h), and the modification treatment with the processing gas is performed again. Here, since a predetermined amount of implanted ions 66 have already been removed from the hardened portion 63b, ozone and water vapor molecules are likely to attack the carbon atoms of the resist material constituting the hardened portion 63b. As a result, the modification treatment of the hardened portion 63b further proceeds.
[0057]
In this way, when the wafer W on which the modification process of the curing unit 63b has further progressed is transferred to the cleaning processing unit (CNU) 12a (12b to 12d) and subjected to a water washing process, the wafer W is changed to water-soluble in the curing unit 63b. Since the portion is removed, the dissolution of the implanted ions 66 from the hardening portion 63b is promoted when the wafer W is subsequently processed with the ion dissolving chemical solution. Thus, the hardened portion 63b that has been subjected to the second treatment with the ion-dissolved chemical solution is in a state that can be easily removed by the APM chemical treatment. By repeating Step 4 to Step 6 as a series of processes as many times as necessary, the cured portion 63b is completely removed from the wafer W by the APM chemical liquid process, and then the wafer W is subjected to the APM chemical process.
[0058]
The wafer W from which the resist cured film 63 has been removed by the processing in the cleaning processing unit (CNU) 12a (or 12b to 12d) is transferred to the wafer placement unit (TRS) 13a, from which the wafer transfer device 7 It is accommodated in a predetermined position.
[0059]
In the above-described processing steps 4 to 6 in the processing process, the dose amount of ions to the wafer W is 10.¹⁵/ Cm²It is suitably performed in the above case. This is a dose of 10¹⁵/ Cm²This is because the cured portion 63b in the resist cured film 63 becomes difficult to peel, and it is extremely difficult to remove the resist cured film 63 from the wafer W only in Steps 4 and 5. In contrast, the dose amount is 10¹⁵/ Cm²If it is less than this, the cured portion 63b in the resist cured film 63 may be easily denatured to be water-soluble by a processing gas containing ozone and water vapor. In this case, the resist cured film 63 can be removed from the wafer W only in Step 4 and Step 5. Therefore, step 6 and step 7 can be omitted.
[0060]
As mentioned above, although embodiment of this invention has been described, this invention is not limited to such a form. For example, in the above description, the wafer W is processed with a processing gas containing ozone and water vapor, followed by a water washing process, and then a process of dissolving implanted ions with a chemical solution. The wafer W can also be processed according to the steps shown in the flowchart of FIG. In the process shown in FIG. 9, first, the processes of Step 1 to Step 4 shown in FIG. 7 are performed. That is, the insulating film 61 and the resist film 62 are formed on the wafer W, and then ion implantation is performed (step 3). As a result, the resist film 62 is transformed into a resist cured film 63. Next, the wafer W is processed by a processing gas containing ozone and water vapor to denature the resist cured film 63 (step 4). Next, the wafer W is processed with an ion-dissolving chemical without performing a water-washing process, and a process for dissolving implanted ions from the resist cured film 63 is performed (step 5A). Subsequently, the wafer W is subjected to a water washing process (step 6A). As a result, when the resist cured film 63 is removed from the wafer W, the processing of the wafer W is terminated.
[0061]
In the processing method shown in FIG. 9, Steps 4, 5 A, and 6 A may be repeated as a series of processing until the resist cured film 63 is completely removed from the wafer W. Further, if necessary, Steps 4, 5A, and 6A may be repeated a plurality of times as a series of processes, and finally the APM chemical solution process may be performed.
[0062]
Further, when the entire resist film 62 is hardened due to the implanted ions, it is also preferable to process the wafer W according to the steps shown in the flowchart of FIG. That is, the insulating film 61 and the resist 62 film are formed on the wafer W according to steps 1 to 3 shown in FIG. 7, and ion implantation is performed. As a result, the resist film 62 becomes a resist cured film 63. Next, the ion-dissolved ion solution is dissolved by the ion-dissolving chemical solution (step 4B), then the wafer W is subjected to a modification process using a processing gas containing ozone and water vapor (step 5B), and the wafer W is subjected to a water washing process (step 5B). Step 6B). Here, if the resist cured film 63 is substantially completely removed, APM chemical treatment is performed on the wafer W to remove particles adhering to the surface of the wafer W (step 7B). On the other hand, if the resist cured film 63 remains on the wafer W after step 6B, steps 4B to 6B are repeated as a series of processes until the resist cured film 63 is substantially completely removed from the wafer W, and thereafter APM chemical treatment in step 7A is performed.
[0063]
In the processing method shown in FIG. 10, if the resist cured film 63 is completely removed after step 6B, the processing of the wafer W may be terminated without performing the APM chemical solution processing (step 7B). . Further, when Steps 4B to 6B are performed a plurality of times as a series of processes, if the resist cured film 63 can be removed by the APM chemical solution process (Step 7B) after the end of the second and subsequent Steps 4B, Step 4B After that, step 7B may be performed.
[0064]
In the above description, an apparatus (so-called single wafer processing apparatus) that processes the wafers W one by one is shown as the film removing apparatus 100. However, the resist film modification process, the wafer W washing process, and the implantation into the resist film are performed. The dissolved ion removal process may be performed using an apparatus (so-called batch type processing apparatus) that processes a plurality of (for example, 25) wafers W at a time.
[0065]
In the above description, the case where ions are implanted into the wafer W has been described, but the target to which ions are implanted may be an insulating film, a semiconductor film, or a conductive film formed on the wafer W. Moreover, although the semiconductor wafer was illustrated as a board | substrate, the board | substrate is not limited to this, The glass substrate used for a liquid crystal display device (LCD) may be sufficient. Furthermore, the processing gas may contain another component other than ozone and water vapor, for example, a gas such as hydrogen peroxide.
[0066]
【The invention's effect】
As described above, according to the present invention, the resist film that has been hardened by the ion implantation process and is hardly peelable can be removed from the substrate without damaging the underlying layer. The remarkable effect that quality is improved is acquired.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a schematic configuration of a wafer processing system.
FIG. 2 is a schematic plan view of a film removing apparatus.
FIG. 3 is a schematic front view of the film removing apparatus.
FIG. 4 is a schematic rear view of the film removing apparatus.
FIG. 5 is a schematic cross-sectional view of a film modification unit (VOS) provided in the film removal apparatus.
FIG. 6 is a schematic sectional view of a cleaning processing unit (CNU) provided in the film removing apparatus.
FIG. 7 is a flowchart showing a resist mask removing process.
FIG. 8 is an explanatory view schematically showing a schematic form change of a wafer in a resist mask removing process.
FIG. 9 is a flowchart showing another resist mask removal step.
FIG. 10 is a flowchart showing still another removal process of the resist mask.
[Explanation of symbols]
2; Processing station
3: Transfer station
4: Carrier station
12a-12d; Cleaning unit (CNU)
15a-15h; membrane modification processing unit (VOS)
61; insulating film
62; resist film
63: Resist cured film
63a; ion non-retention part
63b; Curing part
66; Implanted ions
71; Spin chuck
100; film removing apparatus
104; ion implantation apparatus
W: Wafer (substrate)

Claims (3)

A substrate processing method for removing a resist film from a substrate having a modified resist film by implanting predetermined ions,
Said substrate having a resist film is treated with a process gas containing ozone and water vapor, and denaturing the resist portion which ions are not retained in the film to water-soluble,
A step of the process a substrate processed by water washing treatment by the gas, which divided the modified portion in the water-soluble by the treatment gas in the resist film,
Treating the washed substrate with a chemical solution that dissolves the predetermined ions, and dissolving the ions in the remaining resist film ;
Removing the resist film remaining from the substrate by cleaning the substrate treated with the chemical solution with a predetermined cleaning solution;
A substrate processing method comprising: The step of treating the substrate with the treatment gas, the step of washing the substrate treated with the treatment gas, and the step of treating the washed substrate with the chemical solution are repeated a plurality of times. The substrate processing method according to claim 1 . Ion implantation into the substrate with a resist film, wherein the predetermined ions are implanted, according to claim 1 or claim, characterized in that the ion dose is being performed such that the 10 15 ^/ cm ² or more 3. The substrate processing method according to 2.

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