JP2003145014A - Rotary coating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary coating apparatus in which a gas flowing along the surface of a semiconductor wafer is stabilized. SOLUTION: The rotary coating apparatus 10 is provided with a chamber 12, a supporting table 16 arranged rotatably in the chamber and for supporting the semiconductor wafer W, a liquid chemical dropping apparatus 20 for dropping a liquid chemical to be applied on the wafer supported by the supporting table 16 and a rotary driven gas flow producing apparatus 40 in which an inside opening part 50 is arranged oppositely to the outer circumferential edge of the wafer supported by the supporting table and which has a flow passage extending to an outside opening part 52 from the inside opening part. In the structure, when the gas flow producing apparatus is rotary driven, the gas on the wafer is sucked by the inside opening of the gas flow producing apparatus and the gas on the substrate to be treated flows in a stable state like a laminar flow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spin coating apparatus for dropping a chemical liquid on a substrate to be processed such as a semiconductor wafer while rotating the substrate and applying the chemical liquid to the entire surface of the substrate.

[0002]

2. Description of the Related Art A spin coater is used in a semiconductor manufacturing process such as a cleaning process, a resist coating process, and in recent years an insulating film forming process. As shown schematically in FIG. 5, a conventional general spin coating apparatus includes a chamber 1, a rotatable support base 2 that is disposed in the chamber 1 and supports a semiconductor wafer W that is a substrate to be processed, and a support. It has a drive device 3 for rotationally driving the table 2 and a chemical droplet dropping device 4 for dropping a chemical solution on the surface of the semiconductor wafer W supported on the support table 2. In addition, in resist coating and insulating film formation, a laminar flow (laminar flow) is formed along the surface of the semiconductor wafer W so that the film formed on the semiconductor wafer W has a uniform and constant thickness. Clean air or a suitable gas (hereinafter collectively referred to as “gas”) is introduced from above the support base 2.

Further, the turbulence of the air flow generated when the semiconductor wafer W is rotated is prevented, and the chemical solution scattered by the rotation of the semiconductor wafer W is prevented from adhering to the inner wall surface of the chamber 1 and other constituent members. A fixed, substantially cylindrical member 5 is provided around the circumference of 2. Then, the gas flowing along the semiconductor wafer W causes the support base 2 and the substantially cylindrical member 5 to move.
It is configured so that it can be pulled downward from between.

[0004]

However, in the conventional spin coating apparatus having the above-mentioned structure, the semiconductor wafer W (support base 2) is selected depending on the type of the chemical solution and the coating thickness.
Since the rotational speed of is changed, the pressure distribution in the space inside the substantially cylindrical member 5 is not constant, and turbulent flow may occur.
Such turbulent flow hinders application of the chemical solution on the semiconductor wafer W with a constant thickness. Further, there is a possibility that a part of the gas circulates inside the substantially cylindrical member 5 and winds up the chemical liquid or its solidified substance adhering to the inner wall surface of the substantially cylindrical member 5 to contaminate the surface of the semiconductor wafer W.

Therefore, an object of the present invention is to provide a spin coater capable of stabilizing the flow of gas along the surface of a semiconductor wafer.

[0006]

In order to achieve the above object, a spin coating apparatus according to the present invention includes a chamber and a support that is rotatably disposed in the chamber and supports a substrate to be processed such as a semiconductor wafer. Table, a drive device for rotating the support table, a chemical droplet dropping device for dropping a chemical solution to be coated on the substrate to be processed supported by the support table, and a substrate to be processed whose inside opening is supported by the support table Is arranged opposite to the outer peripheral edge of
An airflow generating device that has a flow path extending from the inner opening toward the outer opening and is driven to rotate.

In this structure, the air flow generator is driven to rotate, so that the gas can be taken in from the inner opening by the action of the centrifugal force and flow out from the outer opening through the flow path. Therefore, the gas on the substrate to be processed is sucked into the inner opening of the airflow generation device, and the gas flows on the substrate to be processed in a stable state such as a laminar flow.

As the air flow generating device, it is conceivable that the device is composed of an inner ring-shaped body fixed to a support and an outer ring-shaped body mounted outside the inner ring-shaped body at a predetermined interval. In this configuration, the inner opening is
It is defined between the inner peripheral portion of the inner annular body and the inner peripheral portion of the outer annular body. The outer opening is defined between the outer peripheral portion of the inner annular body and the outer peripheral portion of the outer annular body. The annular space between the inner annular body and the outer annular body serves as the flow path.

In such an air flow generating device having a double annular body, it is preferable that a part of the inner peripheral wall of the outer annular body is opposed to the outer peripheral edge of the substrate to be processed supported by the support base. This is because it is possible to avoid the contamination of the inner wall surface of the chamber and other components of the spin coating apparatus with the chemical liquid by receiving the chemical liquid scattered from the rotating substrate to be processed.

When the inner ring-shaped member and the outer ring-shaped member are connected by a plurality of ribs which are provided between the inner ring-shaped member and the outer ring-shaped member and are arranged at equal intervals in the circumferential direction, the ribs are directed outward by the rotation of the airflow generator. It is effective to function as a blade that forms an air flow.

Further, vanes may be attached to the outer wall surface of the inner annular body, the inner wall surface of the outer annular body, or both the outer wall surface and the inner wall surface to form an outward airflow by the rotation of the airflow generator.

In addition to the above-mentioned structure, the air flow generating device has a plurality of conduits each having an opening at both ends and having a flow path inside, and the opening at one end becomes the inside opening. It can be considered that they are arranged radially.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the spin coating apparatus according to the present invention. The spin coating apparatus 10 in this embodiment forms a SiO ₂ film on the surface of a semiconductor wafer W, which is a substrate to be processed, and uses Si, O 2 as a chemical solution.
And C _X H _Y is set to be used after dissolved in isopropyl alcohol.

The spin coating apparatus 10 shown in FIG. 1 includes a chamber 12 having a substantially rectangular parallelepiped shape. A base plate 14 is arranged inside the chamber 12, and a support 16 for horizontally supporting the semiconductor wafer W is provided on the base plate 14. The support 16 is preferably of a suction type so that the semiconductor wafer W can be fixed. Further, the support base 16 is rotatably attached to the base plate 14, and is rotationally driven by a drive motor 18 arranged on the lower surface side of the base plate 14.

Further, the spin coating apparatus 10 is provided with a chemical droplet dropping device 20 for dropping or dropping the chemical liquid on the semiconductor wafer W supported by the support 16. The chemical liquid drop device 20 is provided inside the chamber 12 and a chemical liquid tank 22 for storing a chemical liquid that is arranged outside the chamber 12, and the pipe 2
4 has a tubular arm 26 that communicates with the chemical liquid tank 22. The arm 26 is attached to the base plate 14 so that it can swing horizontally. A drive motor 28 for swinging the arm 26 is provided on the lower surface side of the base plate 14. Furthermore,
On the lower surface of the free end of the arm 26, a nozzle 30 for dropping the drug droplet is provided downward.

In such a structure, when the arm 26 is swung, the nozzle 30 for dropping the drug droplets can be arranged immediately above the central portion on the semiconductor wafer W supported by the support 16. The semiconductor wafer W is integrated with the support 16.
When the inside of the chemical liquid tank 22 is pressurized with nitrogen gas or the like by rotating the chemical liquid, the chemical liquid in the chemical liquid tank 22 is discharged from the pipe 24 and the tubular arm 26.
Then, it is dropped or flowed down from the nozzle 30. This chemical spreads from the center of the rotating semiconductor wafer W to the outer peripheral portion and forms a thin film on the entire surface of the semiconductor wafer W.

An opening 32 is formed in the ceiling of the chamber 12 at a position directly above the support base 16. An appropriate gas (preferably clean air) is introduced into the opening 32 so that the gas flows toward the semiconductor wafer W supported by the support 16. this is,
A laminar flow of gas (laminar flow) is to be formed as much as possible along the surface of the semiconductor wafer W during coating. That is, when the solvent is highly volatile like isopropyl alcohol, if the laminar flow is not formed, the state of volatilization of the solvent varies depending on the position on the semiconductor wafer W, and the component of the chemical solution dropped on the wafer surface is Since it may change significantly during coating and affect the film quality, a laminar flow is formed along the surface of the semiconductor wafer W to make the solvent volatilization state constant, and a stable air flow from the wafer center to the outer periphery. The uniform application of the chemical solution is aimed at.

The gas introduced into the chamber 12 is discharged from the exhaust port 34 formed in the lower portion of the chamber 12.
It is discharged to the outside by a vacuum pump (not shown) connected thereto. Further, a filter 36 such as ULPA is provided in the opening 32 of the chamber 12 so that impurities contained in the gas are removed.

Furthermore, the spin coater 10 of the illustrated embodiment
Is an airflow generator 40 arranged so as to surround the support 16.
Is equipped with. The airflow generation device 40 is arranged between the support base 16 and the swing shaft 38 of the arm 26, and supports the support base 1
An inner and outer double annular body 42 arranged coaxially with 6,
It is composed of 44.

The inner annular body 42 is fixed to the lower surface of the support base 16 or the rotation shaft 46 of the support base 16 or the like, and is gradually curved or inclined downward as it goes outward in the radial direction.
Moreover, the outer peripheral portion thereof extends substantially horizontally.

The outer annular body 44 is arranged coaxially with the inner annular body 42, and an annular space is formed therebetween. Similarly to the inner annular body 42, the outer annular body 44 is also curved or inclined downward in the radial direction. Also, the outer annular body 4
4, the inner peripheral edge 48 is located above the surface (upper surface) of the semiconductor wafer W supported by the support 16.
The opening defined by the inner peripheral edge 48 is at least larger than the semiconductor wafer W so that the semiconductor wafer W can be loaded into and unloaded from the support base 16. The outer peripheral portion of the outer annular body 44 extends in a substantially horizontal direction above the outer peripheral portion of the inner annular body 42 with a relatively narrow gap. In such a configuration, the outer annular body 44
An opening portion (inner opening portion) 50 serving as an inlet of the air flow is formed between the inner peripheral portion of the inner peripheral portion of the inner annular body 42 and the inner peripheral portion of the inner annular body 42. The opening 50 is located opposite to the outer peripheral edge of the semiconductor wafer W. Further, an opening (outer opening) 52 serving as an outlet of the airflow is formed between the outer peripheral portion of the outer annular body 44 and the outer peripheral portion of the inner annular body 42, and further, both opening portions 50, 52. A flow path is formed between them.

These annular bodies 42, 44 are connected and integrated by a plurality of ribs 54 arranged at equal intervals in the circumferential direction between the outer peripheral portions.

In FIG. 1, reference numeral 56 is arranged so as to face the opening 52 of the airflow generator 40, and the opening 5
It is an annular receiving member for receiving the gas and the chemical solution flowing out from the chamber 2 and guiding it to the lower part of the chamber 12 from the hole 58 of the base plate 14.

In the chemical solution coating process, the airflow generating device 40 having such a structure rotates integrally with the support 16 and the semiconductor wafer W by the operation of the drive motor 18. As a result, due to the action of centrifugal force, the air flow generation device 4
In the space (flow path) between the inner ring-shaped body 42 and the outer ring-shaped body 44 of 0, an airflow is generated from the opening 50 near the support base 16 to the opening 52 on the outer side. Therefore, the chamber 12
When the gas is introduced from the upper opening 32 of the nozzle and sprayed onto the rotating semiconductor wafer W, the gas is released from the opening 50.
The laminar flow is substantially formed on the surface of the semiconductor wafer W. As described above, when the gas laminar flow is formed on the semiconductor wafer W in the coating process, the solvent (isopropyl alcohol) in the chemical solution is formed.
Volatilization is constant, and the deterioration of the components in the chemical solution is prevented. Further, since the stable laminar flow flows on the surface of the semiconductor wafer W, the chemical liquid dropped on the semiconductor wafer W by the chemical dropping device 20 is smoothly diffused,
The coating film is thin and has a uniform thickness.

Further, depending on the rotation speed of the support base 16,
Although the centrifugal force is weak and the chemical solution may become lumpy at the outer edge portion of the semiconductor wafer W, the laminar flow on the surface of the semiconductor wafer W does not circulate in the space above the semiconductor wafer W, and is sure to occur. Since it flows into the flow path between the inner ring-shaped body 42 and the outer ring-shaped body 44, the chemical liquid can be scattered outward from the outer peripheral edge of the semiconductor wafer W to prevent the formation of lumps.

A portion of the inner wall surface of the outer annular body 44 is the wafer W.
Since it is opposed to the outer peripheral edge of the semiconductor wafer W, the splash of the chemical liquid scattered outward from the outer peripheral edge of the semiconductor wafer W is caught by the inner wall surface of the outer annular body 44 and discharged from the outer opening 52 together with the gas flow. . This protects the inner wall surface of the chamber 12 and the components of the spin coater such as the drug drop lowering device from the splash of the drug. Further, a part of the chemical liquid adhered to the inner wall surface of the outer annular body 44 is solidified into powder and granules.
Since the air flow in the flow path between the inner ring-shaped body 42 and the outer ring-shaped body 44 is flowing outward, it does not return to the semiconductor wafer W and is reliably discharged to the outside. Therefore, the problem of particle contamination of the semiconductor wafer W is significantly reduced.

The preferred embodiments of the present invention have been described above in detail, but it goes without saying that the present invention is not limited to the above-mentioned failure to carry out.

For example, in the above embodiment, the rib 54 is arranged only on the outer peripheral portion between the annular members 42 and 44.
The ribs 54 can be extended to the vicinity of the support base 16 as shown in FIG. 2, which is a plan view of the airflow generation device 40. In this case, the ribs 54 function like the blades of the impeller of the centrifugal blower, so that the outward airflow between the annular bodies 42 and 44 can be more forcedly formed. Of course, it may be curved like the blade of an impeller.

The structure shown in FIG. 2 has an annular body 42, 4
The internal space between the four is divided by ribs 54 to form a plurality of tubular flow paths. Therefore, as in the airflow generation device 140 shown in FIG. 3, a configuration in which a plurality of conduits 100 are radially arranged can also achieve the same effect as the configuration in FIG. That is, when the airflow generation device 140 is rotationally driven together with the support 16 and the semiconductor wafer W, a gas flow that flows from the inner opening 102 of each conduit 100 through the inner flow passage 104 and out the outer opening 106 is formed. To be done.

Further, as a means for forming an outward airflow, a blade 60 as shown in FIG. 4 is provided separately from the rib 54.
Is the inner wall surface of the outer annular body 44, or although not shown,
It may be provided on the outer wall surface of the inner annular body 42, or between both. In FIG. 4, the same or corresponding parts as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The configuration in which the ribs 54 are extended (FIG. 2), the configuration in which a plurality of conduits 100 are provided (FIG. 3), and the configuration in which the blades 60 are provided (FIG. 4) all positively guide the gas to the outside. Even when the support base 16 rotates at a low speed, it is extremely effective in helping to form a laminar flow on the semiconductor wafer W.

Further, in the above embodiment, the coating process for forming the SiO ₂ film which is the insulating film on the semiconductor wafer W has been described, but the spin coating apparatus according to the present invention can be used for the cleaning process and the resist coating process. . In such a case, since the components of the chemical liquid are different, the gas introduced into the chamber 12 by the gas supply means may be different from air, and the gas supply means itself may be unnecessary.

[0034]

As described above, according to the present invention, the gas flows stably from the center to the outside along the substrate to be processed such as a semiconductor wafer, so that the coating on the substrate is kept constant. Can be done in different thicknesses. In addition, since the gas does not circulate above the substrate to be processed, it is possible to prevent a situation in which particles contaminate the substrate to be processed due to the circulation flow. Therefore, when the spin coater according to the present invention is used in the insulating film forming process of semiconductor manufacturing, it contributes to the improvement of the performance and yield of the semiconductor device as a product.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a spin coating apparatus according to the present invention.

FIG. 2 is a plan view showing a modified example of the airflow generation device in FIG.

FIG. 3 is a plan view similar to FIG. 2, showing another embodiment of the airflow generation device.

FIG. 4 is a schematic cross-sectional view showing a modified example of the spin coater of FIG.

FIG. 5 is a schematic sectional view showing a conventional spin coating apparatus.

[Explanation of symbols]

10 ... Spin coating device, 12 ... Chamber, 16 ... Support base,
16 ... Drive motor (drive device), 20 ... Drug drop lowering device,
32 ... Openings (gas supply means), 40, 140 ... Airflow generators, 42 ... Inner annular body, 44 ... Outer annular body, 48 ...
Inner peripheral edge, 50, 102 ... Inner opening, 52, 106 ...
Outer openings, 54 ... Ribs, 60 ... Vane, 100 ... Conduit, 104 ... Gas flow path.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toru Ikeda             14-3 Shinizumi, Narita City, Chiba Prefecture Nogedaira Industrial Park               Applied Materials Japan Co., Ltd.             Inside the company (72) Inventor Lily Pan             United States of America, California,             Fremont, Cabrillo Drive             35694 (72) Inventor Rick Robert             14-3 Shinizumi, Narita City, Chiba Prefecture Nogedaira Industrial Park               Applied Materials Japan Co., Ltd.             Inside the company F term (reference) 2H025 AA18 AB16 EA05                 4F042 AA07 AB00 BA05 EB05 EB09                       EB13 EB17 EB24 EB29                 5F045 AB32 BB14 EB20 EF13                 5F046 JA02 JA05 JA06 JA07 JA08

Claims (7)

[Claims] 1. A chamber, a support base rotatably arranged in the chamber for supporting a substrate to be processed, a drive device for rotating the support base, and a substrate to be processed supported by the support base. A liquid drop lowering device for dropping a liquid chemical to be applied, and an inner opening is arranged to face an outer peripheral edge of a substrate to be processed supported by the support table, and extends from the inner opening toward an outer opening. An air flow generating device having a flow path and being driven to rotate, a spin coating device. 2. The airflow generation device includes an inner annular body fixed to the support base, and an outer annular body attached to the outer side of the inner annular body at a predetermined interval. Is formed between the inner peripheral portion of the inner annular body and the inner peripheral portion of the outer annular body, the outer opening is an outer peripheral portion of the inner annular body and an outer peripheral portion of the outer annular body. The spin coating device according to claim 1, wherein the flow path is an annular space formed between the inner annular body and the outer annular body. 3. The spin coating apparatus according to claim 2, wherein a part of an inner peripheral wall of the outer annular body faces an outer peripheral edge of the substrate to be processed supported by the support base. 4. The inner annular body and the outer annular body,
3. A plurality of ribs, which are provided between the two and are arranged at equal intervals in the circumferential direction, are connected to each other, and the ribs function as blades that form an outward airflow by the rotation of the airflow generation device. The spin coating apparatus according to item 3. 5. A blade for forming an outward airflow by rotation of the airflow generator is attached to an outer wall surface of the inner annular body, an inner wall surface of the outer annular body, or both of the outer wall surface and the inner wall surface. The spin coating device according to claim 2 or 3. 6. The airflow generator has a plurality of conduits each having an opening at both ends and having a flow path inside, and the conduits are radially arranged so that the opening at one end becomes the inside opening. The spin coater according to claim 1, which is configured as follows. 7. The spin coating apparatus according to claim 1, further comprising a gas supply unit that causes a gas to flow down from above the support table toward the substrate to be processed supported by the support table.