JP4347785B2 - Substrate rotating processing equipment - Google Patents

Description

  In the present invention, a semiconductor wafer, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, a substrate for an optical disk, etc. are held in a horizontal position and rotated about a vertical axis to rotate the substrate surface to a cleaning solution, a coating solution, a developing solution, etc. The present invention relates to a substrate rotating type processing apparatus that supplies the processing liquid and performs substrate processing such as cleaning, coating, and development.

  When a substrate such as a semiconductor wafer is held in a horizontal position by a spin chuck and rotated around the vertical axis, a processing liquid such as pure water is supplied to the substrate surface to supply the substrate surface when cleaning the substrate. The cleaned cleaning solution is diffused to the periphery of the substrate by centrifugal force, and the used cleaning solution is scattered from the periphery of the substrate to the periphery. A cup is placed around the substrate held by the spin chuck so as to surround the side and bottom of the substrate, and used cleaning liquid that has scattered from the substrate to the periphery collides with the inner wall surface of the cup and is captured. Then, it flows down on the inner wall surface of the cup, is collected at the bottom of the cup, and is discharged and collected through a drain pipe from a drain port provided at the lower part of the cup (see, for example, Patent Document 1). ).

Conventionally, cups for recovering the processing liquid scattered from the substrate to the surrounding area have been conventionally made of fluororesins such as polytetrafluoroethylene (PTFE), plastic materials such as polyvinyl chloride (PVC) and polypropylene (PP), or stainless steel. Although it is made of a metal material such as steel, most cups are now made of resin. The main function of this cup is to prevent the processing liquid splashed from the substrate to the surroundings from scattering to the outside of the substrate processing section, but at the same time, the processing liquid is collected and quickly collected at the bottom of the cup. It is to flow to the drainage port. By the way, in general, the plastic material forming the cup is hydrophobic, but when the cup is used for a long time, the inner wall surface of the cup becomes hydrophilic. This is because the surface condition changes due to deterioration of the inner wall surface of the cup due to contact with the processing liquid, composition change, deposition of processing liquid components and impurities attached, etc. is there.
Japanese Patent Application Laid-Open No. 10-323633 (page 3, FIG. 1)

  FIG. 4 is a schematic diagram showing a schematic configuration of the substrate rotation processing apparatus. In the figure, 1 is a spin chuck for holding the substrate W in a horizontal position, 2 is a rotation support shaft for supporting the spin chuck 1 holding the substrate W and rotating it around a vertical axis, and 3. , A cup for collecting the processing liquid, and 4 is a drainage part for discharging and collecting the processing liquid. When the cup 3 is formed of a hydrophobic material, the inner wall surface of the cup 3 repels the processing liquid when a hydrophilic processing liquid collides with the cleaning liquid such as pure water. For this reason, as shown in FIG. 4A, the processing liquid splashed from the surface of the substrate W to the periphery and collided with the inner wall surface of the cup 3 bounces off the inner wall surface, and a part of the processing liquid reappears on the surface of the substrate W. Adhere to. At this time, if the processing liquid contains impurities such as a used cleaning liquid, the impurities in the processing liquid become particles and contaminate the substrate W, and the processing liquid adheres to a part of the inner wall surface of the cup. If it is dry, it causes a problem that it becomes particles and adheres to the surface of the substrate W together with the treatment liquid bounced off the inner wall surface, thereby contaminating the substrate W. On the other hand, when the inner wall surface of the cup 3 is hydrophilic, as shown in FIG. 4 (b), the hydrophilic processing liquid that has scattered from the surface of the substrate W to the periphery and collided with the inner wall surface of the cup 3. Spreads in the form of a thin film on the inner wall surface, flows down to the bottom of the cup 3 and is discharged through the drainage part 4. However, since the processing liquid slowly flows on the inner wall surface of the cup 3, it takes longer time for the processing liquid to stay on the inner wall surface of the cup 3. As a result, the processing liquid adheres to the inner wall surface of the cup and is dried. However, there is a problem that impurities and processing solution components are likely to be deposited on the inner wall surface of the cup 3, which causes substrate contamination.

  The present invention has been made in view of the circumstances as described above, and prevents the processing liquid splashed from the surface of the rotating substrate from splashing on the inner wall surface of the cup, and the processing liquid on the inner wall surface of the cup. It is possible to remove the cause of substrate contamination caused by the cup by staying for a long time and preventing the treatment liquid from adhering to the inner wall surface of the cup and drying to deposit impurities and treatment liquid components on the inner wall surface of the cup. An object of the present invention is to provide a substrate rotating type processing apparatus.

  The invention according to claim 1 is a substrate holding means for holding the substrate in a horizontal position, a substrate rotating means for rotating the substrate held by the substrate holding means about a vertical axis, and a substrate held by the substrate holding means. A processing liquid supply means for supplying a processing liquid to the surface of the substrate, and a container shape having an upper surface opened, and is disposed so as to surround a side and a lower side of the substrate held by the substrate holding means. In a substrate rotation type processing apparatus provided with a cup for collecting scattered processing liquid, at least a portion of the inner wall surface of the cup that collides with the processing liquid scattered from the substrate to the periphery and a peripheral portion thereof are hydrophilic. It is characterized by mixing a surface and a hydrophobic surface.

  According to a second aspect of the present invention, in the substrate rotation processing apparatus according to the first aspect, the hydrophilic surface and the hydrophobic surface are mixed in stripes extending in the horizontal direction.

  The invention according to claim 3 is the substrate rotation processing apparatus according to claim 1, wherein the hydrophilic surface and the hydrophobic surface are mixed in a checkered pattern.

In the substrate rotating type processing apparatus according to the first aspect of the present invention, a hydrophilic surface and a hydrophobic surface are mixed in the portion of the inner wall surface of the cup where the processing liquid splashed from the substrate to the periphery collides with the peripheral portion. As a result of the surface treatment, the rebound of the hydrophilic treatment liquid is reduced compared to a cup whose entire surface is a hydrophobic surface, and the treatment which has collided with the hydrophobic surface and diffused on the surface Since the liquid quickly flows to the adjacent hydrophilic surface and aggregates on the hydrophilic surface, the treatment liquid is unlikely to rebound. In addition, the treatment liquid that has collided with the hydrophilic surface is unlikely to rebound from the beginning. Therefore, it is possible to prevent the processing liquid splashing from the substrate and colliding with the inner wall surface of the cup from bouncing back on the inner wall surface, and a part of the used processing liquid is reattached to the surface of the substrate. On the other hand, the treatment liquid that collides with the hydrophilic surface and spreads in the form of a thin film and flows from the hydrophobic surface to the hydrophilic surface and agglomerates flows down from the hydrophilic surface when growing into droplets of a certain size. As a result, the time to stay on the hydrophilic surface is shortened. Therefore, it is possible to prevent the treatment liquid from adhering to the inner wall surface of the cup and drying to deposit impurities and treatment liquid components on the inner wall surface of the cup.
Thus, when the substrate rotating processing apparatus of the invention according to claim 1 is used, the processing liquid splashed from the surface of the rotating substrate to the surroundings is prevented from splashing on the inner wall surface of the cup, and on the inner wall surface of the cup. Since the treatment liquid adheres and is dried and impurities and treatment liquid components are prevented from being deposited on the inner wall surface of the cup, the cause of substrate contamination caused by the cup can be removed.

  In the substrate rotating type processing apparatus according to the second aspect of the present invention, the hydrophilic surface and the hydrophobic surface are mixed in a stripe shape extending in the horizontal direction, so that the above-described operational effect according to the first aspect is reliably exhibited.

  In the substrate rotating type processing apparatus according to the third aspect of the present invention, the hydrophilic surface and the hydrophobic surface are mixed in a checkered pattern, so that the above-described operational effect according to the first aspect is reliably exhibited.

The best embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 shows an example of an embodiment of the present invention, and is a longitudinal sectional view showing a schematic configuration of a main part of a substrate rotating processing apparatus, for example, a substrate rotating cleaning apparatus (spin scrubber).

  The cleaning apparatus includes a spin chuck 10 that holds a substrate W such as a semiconductor wafer in a horizontal posture, and the substrate W held by the spin chuck 10 is connected to a rotation support shaft 12 that supports the spin chuck 10. The motor 14 is rotated in the horizontal plane around the vertical axis. Around the substrate W, there is disposed a cup 16 which is formed in a container shape so as to surround the side and bottom of the substrate W which is opened on the upper surface and held by the spin chuck 10. Inside the cup 16, a truncated cone-shaped rectifying member 18 is disposed below the substrate W held by the spin chuck 10, and a support cylinder 20 is integrally fixed to the center of the rectifying member 18. Yes. The rotation support shaft 12 is inserted into the support cylinder 20. The cup 16 and the rectifying member 18 are bent and connected integrally so that the bottom wall portion of the cup 16 wraps around the bottom surface portion of the rectifying member 18. The support cylinder 20 and the rotation support shaft 12 are not connected. Therefore, the cup 16, the rectifying member 18 and the support cylinder 20 are integrated with the spin chuck 10, the rotation support shaft 12 and the spin motor 14 in the vertical direction. It is possible to move up and down between a position at the time of cleaning the substrate and a position at the time of loading / unloading the substrate below it by a lifting mechanism (not shown).

  A cleaning liquid supply nozzle 22 that supplies a cleaning liquid such as pure water to the surface of the substrate W is disposed above the substrate W held by the spin chuck 10. The cleaning liquid supply nozzle 22 can be retracted to the outside of the cup 16 from the illustrated position. Although not shown, a rotary cleaning brush for scrub cleaning while scanning the surface of the substrate W is installed above the substrate W held by the spin chuck 10. It is supported movably.

  The cup 16 is formed in the shape of a circular truncated cone and has an upper wall portion 24 whose inner wall surface is expanded downward. The cup 16 is connected to the lower edge of the upper cup portion 24 and is formed in a cylindrical shape. A lower cup portion 26 having a bottom wall portion bent so as to wrap around, and an annular portion 28 connected to the upper end edge of the upper cup portion 24 and projecting horizontally inward from the upper end edge; They are integrated into a container shape. The upper cup portion 24 is disposed at a height including a horizontal plane on which the substrate W held by the spin chuck 10 is positioned during substrate cleaning, and the cleaning liquid scattered from the surface of the substrate W to the surroundings is contained in the upper cup portion 24. Collide with the wall. A drainage port 30 is formed in the bottom wall portion of the lower cup portion 26, and a drain pipe 32 is connected to the drainage port 30. Further, an exhaust pipe 34 opened at a position facing the lower surface of the rectifying member 18 is provided on the bottom wall portion of the lower cup portion 26 so that the exhaust in the cup 16 is exhausted through the exhaust pipe 34. It has become.

  The cup 16 configured as described above is formed of a fluororesin such as PTFE, or a plastic material such as polyvinyl chloride or polypropylene. Then, at least the upper cup portion 24 of the cup 16, that is, the inner wall surface of the upper cup portion 24, which is a portion where the cleaning liquid scattered from the surface of the substrate W collides, is hydrophilic as shown in FIG. 2. The surface treatment is performed so that the surface 36 and the hydrophobic surface 38 are mixed in stripes extending in the horizontal direction. As a method of partially hydrophilizing the inner wall surface of the upper cup portion 24 formed of a hydrophobic plastic material, for example, the inner wall surface is physically roughened using an extremely fine file. Or plasma treatment, that is, use a nozzle with a plasma generating part at the tip, scan the inner wall surface with the nozzle tip to roughen the inner wall surface, use chemicals, and use chemical resistant tape etc. There are methods such as applying a chemical to the inner wall surface after partially masking the surface to roughen the surface, or depositing a hydrophilic material in a thin film on the inner wall surface of the cup. It may be something like this.

  FIG. 3 shows another embodiment in which a hydrophilic surface and a hydrophobic surface are mixed on the inner wall surface of the upper cup portion. As shown in a development view in FIG. 3, the inner wall surface of the upper cup portion 40 is made hydrophilic. Surface treatment may be performed so that the hydrophobic surface 42 and the hydrophobic surface 44 are mixed in a checkered pattern. Further, other forms such as a scale pattern combining triangles or a honeycomb pattern combining hexagons may be used. Note that the hydrophilic surface 36 and the hydrophobic surface 38 may be mixed in a part of the inner wall surface of the upper cup portion 24 instead of the entire inner wall surface of the upper cup portion 24. In addition, a part or the whole of the inner wall surface of the lower cup portion 26 other than the upper cup portion 24 may be surface-treated so that a hydrophilic surface and a hydrophobic surface are mixed.

  In this substrate rotation type cleaning apparatus, a hydrophilic surface 36 and a hydrophobic surface 38 are formed on the inner wall surface of the upper cup portion 24 where the cleaning liquid such as pure water scattered from the substrate W to the periphery of the cup 16 collides. Since they are mixed, the rebound of the cleaning liquid is reduced as compared with a cup in which the inner wall surface of the upper cup portion 24 remains a hydrophobic surface. Further, the cleaning liquid that collides with the hydrophobic surface 38 of the inner wall surface of the upper cup portion 24 and diffuses on the surface quickly flows to the hydrophilic surface 36 adjacent to the upper and lower sides and aggregates on the hydrophilic surface 36. The cleaning liquid is less likely to rebound. And since the washing | cleaning liquid which collided with the hydrophilic surface 36 of the inner wall surface of the upper side cup part 24 spreads in a thin film form, it does not produce a rebound from the first. For this reason, it is prevented that the cleaning liquid splashed from the substrate W and collided with the inner wall surface of the upper cup portion 24 rebounds on the inner wall surface, and a part of the used cleaning liquid is reattached to the surface of the substrate W. Therefore, there is no concern that impurities contained in the used cleaning liquid become particles and contaminate the substrate W.

  On the other hand, the cleaning liquid that collides with the hydrophilic surface 36 on the inner wall surface of the upper cup portion 24 and spreads in a thin film shape and flows from the hydrophobic surface 38 to the hydrophilic surface 36 and aggregates is a droplet of a certain size. When it grows, it flows down from the hydrophilic surface 36 and flows to the hydrophobic surface 38 adjacent to the lower side, so that the time spent on the hydrophilic surface 36 is shortened. Therefore, it is possible to prevent the cleaning liquid from adhering to the inner wall surface of the upper cup portion 24 and drying and depositing impurities in the used cleaning liquid on the inner wall surface of the upper cup portion 24. The used cleaning liquid that has flowed down from the inner wall surface of the upper cup portion 24 to the inner wall surface of the lower cup portion 26 quickly flows down on the inner wall surface of the lower cup portion 26, which is a hydrophobic surface, and is trapped in the inner bottom portion. Collected, quickly flows toward the drainage port 30 provided in the bottom wall portion of the lower cup portion 26, and is discharged from the cup 16 through the drain pipe 32 through the drainage port 30 and collected.

  In the above-described embodiment, the case where the present invention is applied to the substrate rotating cleaning apparatus has been described. However, the present invention is not limited to the substrate rotating processing apparatus, such as a developing device (spin developer), a coating device (spin coater), and the like. The same applies to. Moreover, the structure of the cup is not limited to that described in the above embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view which shows an example of embodiment of this invention, and shows schematic structure of the principal part of the board | substrate rotary cleaning apparatus which is a substrate rotary processing apparatus. It is a figure shown in the state which expand | deployed the upper cup part of the cup which is a component of the board | substrate rotation type cleaning apparatus shown in FIG. It is a figure which shows another embodiment of this invention, and shows the state which expand | deployed the upper cup part of the cup which is a component of a board | substrate rotary cleaning apparatus. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows schematic structure of a board | substrate rotation type processing apparatus, Comprising: (a) demonstrates a mode at the time of the hydrophilic process liquid which scattered from the surface of the board | substrate colliding with the hydrophobic cup inner wall surface. (B) is a figure for demonstrating a mode at the time of the hydrophilic processing liquid which scattered from the surface of the board | substrate colliding with the hydrophilic inner surface of a cup.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Spin chuck 12 Rotation support shaft 14 Spin motor 16 Cup 18 Rectification member 20 Support cylinder 22 Cleaning liquid supply nozzle 24, 40 Upper cup part 26 Lower cup part 30 Drain port 32 Drain pipe 34 Exhaust pipe 36, 42 Upper cup part inner wall surface Hydrophilic surface 38, 44 Hydrophobic surface of the inner wall surface of the upper cup part W substrate

Claims (3)

A substrate holding means for holding the substrate in a horizontal position;
Substrate rotating means for rotating the substrate held by the substrate holding means around a vertical axis;
A processing liquid supply means for supplying a processing liquid to the surface of the substrate held by the substrate holding means;
A cup having an upper surface opened, disposed so as to surround the side and lower side of the substrate held by the substrate holding means, and a cup for recovering the processing liquid scattered from the substrate to the surroundings;
In the substrate rotation processing apparatus provided with
A substrate rotating processing apparatus, wherein a hydrophilic surface and a hydrophobic surface are mixed in at least a portion of the inner wall surface of the cup where a processing liquid scattered from the substrate to the periphery collides with the peripheral portion. The substrate rotating processing apparatus according to claim 1, wherein the hydrophilic surface and the hydrophobic surface are mixed in stripes extending in the horizontal direction. The substrate rotation processing apparatus according to claim 1, wherein the hydrophilic surface and the hydrophobic surface are mixed in a checkered pattern.

Images