JP2003136009A - Rotary coater and its coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid coater and its coating method for forming a film having uniformity on a substrate such as a semiconductor wafer, liquid- crystal substrate, or a photomask substrate. SOLUTION: The coater includes a holding means (30, 31, 38) for holding a semiconductor wafer 32, a means for dropping liquid on the wafer, and a rotating means (11, 12, 15) for rotating the wafer. The holding means is connected to the rotating means, and capable of providing a closed space. In the space, there are provided a fixing part (33) for fixing substantially horizontally the wafer, and a peripheral part (36) including the space demarcated by a slantingly extending surface (35) from the fixed part to the outside. The peripheral part includes a space positioned in the below of the fixed part.

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 and a coating method used for processing a substrate (for example, a semiconductor wafer, a liquid crystal substrate, or a photomask substrate), and more particularly to a sealed space around the substrate, The present invention relates to a coating apparatus and method for coating a liquid such as a resin thereon to form a uniform film on a substrate.

[0002]

2. Description of the Related Art Conventionally, semiconductor wafers, liquid crystal substrates,
Alternatively, a step of applying a liquid is performed to process a substrate such as a photomask substrate. For example, when manufacturing a semiconductor integrated circuit, a liquid such as photoresist, SOG, or polyimide resin is applied onto a semiconductor wafer in a photolithography or flattening process step. What is required in such liquid application is to form a film having a uniform thickness by the application, or to form a flat film on a semiconductor wafer including a step. In order to meet such demands, various spin coating devices (spin coaters) have been improved.

For example, in the invention disclosed in Japanese Patent Laid-Open No. 6-160404, as shown in FIG. 1, a semiconductor wafer 5 is placed on a chuck 7 attached to a motor 9, and the periphery of the wafer is covered by a cup and a lid. Adopt a structure that seals. This suppresses the turbulence of the air flow, makes the resist coating uniform, and eliminates coating unevenness. In addition to the above publications,
The following is disclosed as a technique for forming a sealed structure around a semiconductor wafer.

Japanese Patent Laid-Open No. 5-136041 discloses that the chamber 9a is hermetically sealed to reduce fluctuations in atmospheric pressure.
This discloses a technique for reducing the fluctuation of the film thickness on the semiconductor wafer (see FIG. 1).

Japanese Unexamined Patent Publication No. 5-208163 discloses a technique of forming a uniform resist film by supplying a resist from a spray nozzle 18 onto a semiconductor wafer 14 using a closed control chamber 10 (FIG. 1). reference).

Japanese Unexamined Patent Publication No. 2001-23879 discloses a technique for preventing the mist from adhering during photoresist coating by using a closed processing container 2 composed of a lower container 3 and an upper container 4 (FIG. 1). reference).

[0007]

However, when a liquid is applied onto a semiconductor wafer by using the above-mentioned conventional spin coating apparatus, polyimide is particularly formed on a semiconductor wafer on which unevenness or a stepped shape such as a V groove is formed. When a resin is applied to form a film, the film thickness distribution on the semiconductor wafer may not always reach the desired accuracy. In particular, as the diameter of the semiconductor wafer becomes larger, it becomes more difficult to make the film thickness uniform. Further, the spin coating apparatus of the above conventional example uses a hermetically sealed or hermetically sealed chamber or the like to hermetically seal the periphery of the semiconductor wafer and adjust the atmospheric pressure and air flow. However, it does not study the uniformity of the film thickness. Furthermore, when the substrate has a rectangular shape (substrate for liquid crystal or substrate for photomask), it is not always easy to apply the liquid to be dripped uniformly, and uneven coating may occur around the edges or at the edges. There is. The inventor
It has been found that the uniformity of the film thickness formed on a rectangular semiconductor wafer or a rectangular substrate is ultimately due to the shape of the closed space around the base (or substrate).

Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional example and to provide a liquid coating apparatus and a coating method thereof capable of forming a uniform film on a substrate.

Further, an object of the present invention is to provide a liquid coating apparatus capable of forming a flat film on a substrate having a step formed on its surface, and a coating method therefor. Further, the present invention provides a liquid coating apparatus excellent in step coverage capable of forming a film on a substrate having a step formed on its surface so as to follow the shape of the step, and a coating method thereof.

Further, the object of the present invention is to improve productivity,
A liquid coating apparatus for substrate treatment and a coating method therefor, which are relatively low in cost.

Further, an object of the present invention is to provide a liquid coating apparatus provided with a closed chuck having an optimum shape for forming a uniform film on a substrate and a coating method therefor.

[0012]

A liquid coating apparatus according to the present invention comprises a holding means for holding a substrate, a means for dropping a liquid on the substrate, and a rotating means for rotating the substrate. It is defined by a fixing part that is coupled to the rotating means and can provide a closed space, and that fixes the base body in the space substantially horizontally, and an inclined surface that extends from the fixing part to incline outward. An outer peripheral portion including a space, and the outer peripheral portion includes a space located below the fixed portion.

Preferably, the holding means has a liquid storage part communicating with the inclined surface of the outer peripheral part through a through hole, and the liquid storage part includes a space below the outer peripheral space part. Suitably, the liquid storage parts are arranged substantially evenly in the circumferential direction of the outer peripheral part. For example, it is desirable to arrange four at 90 degree intervals.

Preferably, the holding means is connected to the rotating means and has a container means having an opening on one side and a sealing means for sealing the opened one side, thereby providing a sealed space inside. . The sealed space does not necessarily need to be airtight or in a vacuum state, as long as the periphery of the substrate is shielded from the external space.

Preferably, the sealing means comprises an inlet for introducing an inert gas, eg nitrogen gas, into the container means. Further, a filter can be connected to the introduction hole to remove particles such as dust.

[0016] Preferably, the spin coater is provided with an attaching / detaching mechanism for attaching / detaching the sealing means to / from the container means. The attachment / detachment mechanism includes a mechanism for moving the sealing means upward from the container means, and a mechanism for rotatably supporting the sealing means.

Preferably, the dripping means is movable and drips the liquid onto the substrate in the container means when the sealing means is removed from the container means.

[0018] Preferably, the holding means includes a hermetically-sealed chuck coupled to the rotating shaft of the rotating means, and the hermetically-sealed chuck has the fixed portion and the outer peripheral portion. That is, since the hermetically-sealed chuck integrally holds the substrate and connects it to the rotating means, it is not necessary to separately form the substrate holding and the rotating shaft coupling and to connect the both, and the number of steps and cost are reduced. Can be reduced. On the other hand, such an integrated structure allows the sealed space to be more effectively held in a sealed state.

Preferably, the hermetically sealed chuck has a rear flange coupled to the back surface thereof, and the recess formed on the back surface of the chuck and the rear flange form a liquid storage section. Further, a hole for vacuum suctioning the back surface of the base body is formed in the fixing portion of the closed chuck. The base may be, for example, a circular semiconductor wafer, or a liquid crystal substrate or a photomask substrate as a substrate having a rectangular shape.

The method of applying a liquid on a substrate according to the present invention includes the following steps. The step of mounting the substrate on the substrate mounting surface of the hermetically sealed chuck having a space formed on the outer periphery and below the substrate mounting surface, the step of dropping the liquid on the stopped substrate, and the sealing member for the opening surface of the hermetically sealed chuck. And the step of applying a liquid onto the substrate by rotating the substrate in a closed space inside the closed chuck.

Preferably, the liquid applying method includes the steps of positioning a nozzle for dropping the liquid on the opening surface of the closed chuck, and retracting the nozzle from the opening surface after the completion of the dropping of the liquid. An inert gas may be injected into the closed space.

Preferably, the substrate is a semiconductor wafer and the liquid is a polyimide resin. Further, a step is formed on the surface of the semiconductor wafer, and a flattened polyimide film is formed on the surface of the substrate by applying a polyimide resin. The step is a V-shaped groove running in a lattice pattern on the surface. Further, the substrate may be a liquid crystal substrate having a rectangular shape or a photomask substrate.

According to the liquid coating apparatus and the coating method thereof of the present invention, since the holding means for holding the substrate is connected to the rotating means, it can be rotated together with the substrate and the turbulence of the air flow in the closed space can be suppressed. it can. Further, the outer peripheral portion of the holding means includes a space defined by the inclined surface extending from the fixed portion at a position lower than the fixed portion, so that the liquid applied on the substrate flows down from the substrate due to centrifugal force.
Alternatively, when the liquid is blown, these liquids can be guided to the space below through the inclined surface, so that the turbulence of the air flow in the closed space can be suppressed to the minimum.

Further, since the liquid storage portion is connected to the inclined surface of the outer peripheral portion, a proper amount of liquid is stored in the liquid storage portion by centrifugal force. That is, when the space of the liquid storage portion is filled with the liquid through the inclined surface, the through hole that connects the inclined surface and the liquid storage portion is substantially shielded by the liquid. Therefore, the liquid spilled from the substrate can be appropriately held even in the closed space, whereby the air flow can be disturbed or the mist can be prevented from adhering to the substrate. Furthermore, depending on the liquid used, the stored liquid can be reused.

As described above, according to the present invention, by optimizing the shape of the holding means of the liquid coating apparatus, the film thickness formed on the substrate can be made more uniform, and the substrate including steps is formed. However, a flatter film can be formed.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an assembly diagram showing a main configuration of a spin coating apparatus for processing a semiconductor wafer according to an embodiment of the present invention. The spin coater 1 has an A inside the motor cover 10.
The C servo motor 11 is provided, and the drive shaft 12 from the AC servo motor 11 is connected to one end of the spin shaft 15 by the key 14 in the coupling 13. The other end of the spin shaft 15 is connected to the closed chuck 30,
Rotational drive from the AC servo motor 11 is transmitted to the sealed chuck 30.

An adsorption hole 16 is formed that extends in the axial direction from the surface of the other end of the spin shaft 15 to the vicinity of the center thereof in the axial direction. The suction hole 16 further includes a hole that extends substantially horizontally from the center portion and communicates with the outer peripheral surface of the spin shaft 15.

The spin shaft 15 is rotatably supported in the housing 17 by a pair of bearings 18. The pair of bearings 18 are separated by a collar spacer 19, and the outer surface of each bearing 18 is fixed by a C-shaped retaining ring 20 for the shaft. Further, the spin shaft 15 is sealed in the motor flange 21 by a pair of motor seals 22. A through hole that extends in the horizontal direction is formed in the motor flange 21, and the motor flange 21 is positioned so that the through hole communicates with the suction hole 16 of the spin shaft 15 between the pair of motor seals 22. . The through hole of the motor flange 21 is connected to an external vacuum suction device (not shown),
The semiconductor wafer is sealed by the motor seal 22 during vacuum suction.

The upper surface of the motor flange 21 is a retainer 2
It is fixed by 3, and a photo sensor 24 is provided on the upper part thereof. The photo sensor 24 detects the number of rotations of the shaft by the photo sensor cam 25 fixed on the spin shaft 15, and outputs this to the control unit that controls each unit of the spin coating device.

The other end of the spin shaft 15 is received in a hole of a bearing portion 31 provided in the lower portion of the hermetically sealed chuck 30 and fixed by a lock ring 26. Support 2
7 fixes the housing 17 to the motor cover 10, and the cup cap 28 protects the lower part of the closed chuck 30.

The closed chuck 30 has a substantially thin cylindrical shape and provides a closed space therein. The sealed chuck 30 is defined by a vacuum suction portion 33 for mounting and fixing the semiconductor wafer 32, and an inclined surface 35 extending outward through a surface 34 that is one step lower than the surface of the vacuum suction portion 33. It has an outer peripheral portion 36 including a space. The space of the outer peripheral portion 36 is located outside and lower than the mounting surface of the semiconductor wafer 32, and has a substantially U-shaped cross section.

A suction hole 37 is formed substantially at the center of the wafer mounting surface of the vacuum suction portion 33, and the suction hole 37 is formed in the bearing portion 31.
Communicate with the hole. The suction hole 37 communicates with the suction hole 16 of the spin shaft 15 received by the bearing portion 31, thereby making it possible to suck the back surface of the semiconductor wafer 33 placed on the vacuum suction portion 33.

The upper surface of the closed chuck 30 is open, and this opening surface can be closed by the seal member 38. The seal member 38 has a disc shape corresponding to the opening surface, and a packing 39 and a packing retainer 4 are provided on the outer peripheral end thereof.
0 is attached. The packing 39 has a ring shape,
The upper surface is fixed by the packing retainer 40, and the lower surface is brought into contact with the opening surface of the closed chuck 30. In this way, the seal member 38 provides a space for hermetically sealing the inside of the closed chuck 30. A rear flange 41 is attached to the back surface of the hermetically sealed chuck 30, and a liquid storage unit described later is formed here.

Next, the above-mentioned closed type chuck and each part attached thereto will be described in detail. 2 is a top view of the closed type chuck, FIG. 3 is a sectional view taken along line XX of FIG. 2, FIG. 4 is a bottom view of the closed type chuck, and FIG. 5 is an enlarged view of the outer peripheral portion of FIG.

The closed chuck 30 is molded from Delrin resin. The maximum outer diameter of the sealed chuck 30 is 200 m
m, the inner diameter of the opening surface is 150 mm, and the outer diameter of the vacuum suction portion 33 is 90 mm. In this embodiment, it is designed for a semiconductor wafer having a diameter of 5 inches. The outer diameter of the surface 34 that is one step lower than the vacuum suction portion 33 is 120 mm.
It is about 3 mm lower than 3. The outer diameter of the position where the inclined surface 35 inclined further downward from the lower surface 34 contacts the bottom surface is 160 mm. The distance between the vacuum suction unit 33 and the opening surface is 15 mm, and the distance from the bottom surface to the opening surface is 30 mm. Thus, the outer peripheral portion 36 having a space outside the vacuum suction portion 15 and at a position lower than the vacuum suction portion 15 is formed inside the closed chuck 30. Outer part 36
The inner wall of the outermost part of the is formed with a radius of curvature of 6 mm.

A through hole 42 is formed in the inclined surface 35 of the outer peripheral portion 36. The through holes 42 are arranged at intervals of 90 degrees in the circumferential direction. A concave portion or a depression 43 is formed on the back side of the inclined surface 35 by utilizing the inclination. Further, a plurality of screw holes 44 are formed on the back surface in the circumferential direction.

FIG. 6 is a plan view of the rear flange. The rear flange 41 has a disc shape with an opening formed in the central portion, and is molded with Delrin (registered trademark) resin. The outer diameter is 200 mm, and the central opening is 110 m.
m and the thickness is 6 mm. Multiple screw holes 4 in the circumferential direction
5 are formed, and these are in positions corresponding to the screw holes 44 of the closed chuck. Further, the rear flange 41 is formed with four recesses 43a at 90-degree intervals in the circumferential direction. By screwing the rear flange 41 to the back surface of the hermetically sealed chuck 30, the above-mentioned recess 43 is united with the recess 43a of the rear flange 41 to form a sealed space therein. This space functions as a liquid storage unit 43 that stores the liquid dropped on the semiconductor wafer.

FIG. 7 is a sectional view of the seal member. The seal member 38 has a disc shape and is made of Delrin resin. The outer diameter is 146 mm, and the closed chuck 3
It is slightly smaller than the opening diameter of 0. Seal member 38
A shaft attachment portion having an annular protrusion is formed at the center of the, and an attachment / detachment mechanism described later is attached to this portion.

FIG. 8 is a sectional view of the packing, and FIG. 9 is a sectional view of the packing retainer. The packing 39 is made of silicone rubber and has a disk shape with an outer diameter of 164 mm and an inner diameter of 125 mm. The packing retainer 40 is made of Delrin resin and has an outer diameter of 168 mm. The outer peripheral bottom surface has a protrusion 46 for positioning and holding the packing 39. Packing 3
Since 9 has an outer diameter slightly larger than that of the seal member 38, when it is attached to the hermetically-sealed chuck 30 with the upper portion thereof fixed by the packing-holding protrusion 46, the packing 39 is just attached to the hermetically-sealed chuck 30. It abuts the opening surface and seals the both.

FIG. 10 is a view showing an attachment / detachment mechanism for attaching / detaching the seal member to / from the closed chuck. The attachment / detachment mechanism 50 according to the present embodiment is a linear type movable in the vertical direction.
Cylinder 60, stay 62 connected to linear cylinder 60 via bracket 61, bearing case 70 connected to stay 62, and bearing case 7
0, a motor seal housing 80 coupled to the shaft, and a shaft 9 rotatably mounted in the bearing case 70.
It has 0 and.

As shown in FIG. 11, the shaft 90 has a flange formed at one end 91, which is fixed to the shaft mounting portion 51 at the center of the seal member 38 by a screw. Inside the shaft 90, a space 92 having a large inner diameter and a space 93 having a small inner diameter communicating with the space 92 are formed. In the present embodiment, since a structure capable of supplying nitrogen gas as an inert gas into the closed chuck 30 is adopted, a gas introduction hole 52 having an inner diameter of about 2 mm is formed in the shaft mounting portion 51 of the seal member 38. . However, when the supply of the inert gas is unnecessary, the seal member having the gas introduction hole is not necessarily used. By attaching the shaft 90 to the seal member 38, the gas introduction hole 52 communicates with the spaces 92 and 93 in the shaft 90. Although the space 93 is closed on the other end side of the shaft 90, the hole 94 is formed in the radial direction, that is, in the direction perpendicular to the axial direction.
(2.5 mm diameter) is formed, and the space 93 can communicate with the outside through the hole 94.

When nitrogen gas is supplied to the closed chuck 30, it is preferable to remove particles such as dust. Therefore, the filter 9 is provided in the space 92 of the shaft 90.
5 are arranged. One side of filter 95 and space 93
A spring 96 is interposed between and, so that the other surface of the filter 95 is pressed against the shaft mounting portion 51.

The bearing case 70 has a cylindrical shape,
A bearing 72 is provided inside by a C-shaped retaining ring 71.
On the other hand, while the lower part of the bearing retainer 7
3 is attached and the shaft 90 is rotatably supported.

As shown in FIG. 12, the motor seal housing 80 is connected to an annular flange 81, a cylindrical space 82 having a large inner diameter, a space 83 having a small inner diameter communicating with the space 82, and a space 83. And a hole 84 that functions as a nitrogen gas introduction port. Motor housing 80
Is attached to the bearing case 70 by the flange 81, and the spacer 86 is attached by the nut 85 in the space 82.
The shaft 90 is fixed on the bearing 73 via.
The other end of the shaft 90, that is, a portion having a small outer diameter is inserted into the space 83 via an annular retainer 87. In the space 83 of the motor seal housing 80, a recess 89 for mounting the annular motor seal 88 is formed. The motor seal 88 is disposed in the recess 89 and seals the other end of the shaft 90 in the space 83. The hole 94 in the shaft 90 is approximately level with the hole 84 in the motor seal housing,
The nitrogen gas injected from the hole 84 is supplied to the hole 94 of the shaft 90 in the closed space surrounded by the motor seal 88.
Can be introduced into. Therefore, the nitrogen gas introduced from the hole 84 can be supplied into the hole 94 while the shaft 90 is stopped or rotating. The nitrogen gas introduced into the hole 94 is supplied into the closed chuck 30 through the internal spaces 93, 92, the filter 95, and the gas introduction hole 52.

A retainer 63 is fixed to the upper portion of the motor seal flange 80, and the motor seal housing 80
The space 83 is closed.

When the sealing member 38 is opened / closed or detached from the closed chuck 30, the linear cylinder 60 moves in the vertical direction in response to a command from the control unit (not shown) of the spin coater. By preliminarily storing the lowest point and the highest point of the seal member 38 in a memory or the like, the stroke of the linear cylinder 60 in the vertical direction can be automatically controlled.

When the seal member 38 is at the lowest position,
The packing 39 is pressed against the opening surface of the sealed chuck 30, and the elasticity of the packing 39 provides a suitable sealing. When the closed chuck 30 is rotated by the AC servomotor 11, the seal member 38 is also rotated together,
A shaft 90 attached to the seal member 38 is rotatably supported by a bearing 72.

When the seal member is at the highest position, that is, when one surface of the hermetically sealed chuck 30 is open,
The semiconductor wafer 32 is placed on the vacuum suction unit 33 and then vacuum suctioned. Further, a nozzle (not shown) can be moved to substantially the center of the sealed chuck 30, and a liquid to be applied on the semiconductor wafer, for example, a photoresist liquid, SOG, polyimide, etc., is dropped from the nozzle.

Next, a preferable liquid coating method of this embodiment will be described. Here, an example will be described in which a polyimide resin is applied on a semiconductor substrate having a V-shaped groove formed on the surface and flattening treatment is performed.

A semiconductor wafer having a V-shaped groove formed on the surface of a semiconductor substrate is prepared. The V-shaped groove has surfaces inclined in the silicon substrate at an angle of about 45 degrees, and the intersecting angle of these surfaces is about 90 degrees. The depth of the groove is 100-200
Micron, which is formed in a grid pattern on a semiconductor wafer. The groove may include a silicon substrate containing a thin film such as a silicon oxide film or a nitride film. The V-shaped groove functions as an optical waveguide when it is finally packaged.

Next, the linear cylinder 60 is driven to attach the seal member 38 to the hermetic chuck 30 by the attaching / detaching mechanism 50.
To the top point. The semiconductor wafer is placed on the vacuum suction unit 33, and the suction holes 16,
The back surface of the semiconductor wafer is adsorbed via 37. Next, the nozzle is moved to near the center of the closed chuck 30, and the polyimide resin is dropped from there. At this time, the semiconductor wafer 32 is still stopped, the dropped polyimide resin advances to the outer periphery of the wafer with a certain amount of surface tension, and the dropping is finished when the polyimide resin is slightly spilled from there. The polyimide resin spilled from the semiconductor wafer 32 passes through the lower surface 34, the inclined surface 35, the through hole 42, and the rear flange 4.
It slightly collects in the liquid storage portion formed by 1 and the depression 43.

Next, the nozzle is retracted to the home position, the linear cylinder 60 is driven again, and the seal member 38 is lowered. When the seal member 38 reaches the lowest point,
The packing 39 is elastically pressed against the open end of the closed chuck 30. At this point, the internal space of the sealed chuck 30 is shielded from the outside.

The closed chuck 30 is filled with nitrogen gas, and the AC chuck 11 is driven to rotate the closed chuck 30. The timing of introducing the nitrogen gas may be before or during the rotation of the sealed chuck 30. Further, although nitrogen gas is used in the present embodiment, argon gas or the like may be used as the inert gas other than this. The coating conditions of the polyimide resin will be described later, but for example, it is rotated at 500 rpm for 40 seconds, and then 150 times.
Perform high speed rotation for 1 second at 0 rpm. Closed type chuck 30
The sealing member 38 rotates together with the semiconductor wafer 32. At this time, since the internal space is in a sealed state filled with nitrogen gas, air from the outside does not flow in and the air flow inside is not disturbed. Further, the liquid slightly stored in the liquid storage unit 43 due to the rotation of the closed chuck 30 is pushed toward the vertical wall side of the through hole 42 by the centrifugal force,
The through hole 42 is substantially closed. Therefore, the outer peripheral portion 36 in the closed chuck 30 and the liquid storage portion (the depression 43) are shielded. On the other hand, the polyimide resin dropped on the semiconductor wafer 32 and held at a certain thickness by the surface tension is pressed to the outer periphery by the centrifugal force simultaneously with the rotation, falls from the wafer edge, and flows down the surface 34 and the inclined surface 35. But,
Since the through hole 42 is substantially closed as described above, most of the through hole 42 does not pass through the through hole 42 and remains in the outer peripheral portion 36. In this way, fluctuations in the air flow or atmospheric pressure in the internal space can be suppressed as much as possible.

After the application and rotation of the polyimide resin are completed, the semiconductor wafer may be further rotated at a low speed to dry the polyimide resin, if necessary. For example, it is desirable to perform a drying rotation at 300 rpm for about 120 seconds. When the rotation of the closed chuck 30 is stopped, the polyimide resin pushed by the vertical wall of the through hole 42 is returned to the original state by the centrifugal force, and the polyimide resin accumulated in the outer peripheral portion 36 passes through the through hole 42. Liquid storage unit 4
It is automatically recovered to 3. 5-on the semiconductor wafer 32
A 10 micron thick polyimide resin is coated, and the surface including the V-shaped groove is coated with a substantially flat film,
The film thickness distribution over the entire wafer can be made uniform and thinned.

As a result of applying the polyimide resin under the various conditions shown below using the above-mentioned closed chuck, the present inventor can apply a flat film on a semiconductor wafer under all of these conditions. I found that there is. This judgment was performed by baking a semiconductor wafer coated with a polyimide resin at 60 degrees for 5 minutes, then measuring a plurality of points on the surface of the semiconductor wafer with a step gauge, and checking the degree of variations thereof. The drying rotation was 300 rpm / 120 seconds in all cases. Condition 1: 500 rpm / 40 seconds + 1500 rpm / 1s
Condition with drying rotation 2: 500 rpm / 20 seconds + 1000 rpm / 30
s No drying rotation condition 3: 500 rpm / 80 seconds No rotation drying

Although the preferred embodiments of the present invention have been described above in detail, the present invention is not limited to the specific embodiments, but is within the scope of the gist of the present invention described in the claims. In, various modifications and changes are possible.

In this embodiment, a semiconductor wafer is used as a substrate, but other than this, it can be applied to a liquid crystal substrate or a photomask substrate. In particular, when the liquid was applied onto a substrate having a rectangular shape such as a liquid crystal substrate or a photomask substrate, it was possible to apply a liquid with no fringes and no unevenness and uniformity. .

Further, in this embodiment, the polyimide resin is used as the liquid to be dropped, but other resins or liquids may be used. It is possible to use the liquid applied to the substrate to be treated.

Further, in the present embodiment, the application of the liquid in the flattening process of the semiconductor wafer is taken as an example, but the process other than this, for example, the application of the photoresist in the photolithography process may be applied. Further, in this embodiment, Delrin resin is used as the material of the hermetically sealed chuck and the seal member, but other than this, for example, other Teflon (registered trademark) resin or metal such as aluminum may be used.

Further, in the present embodiment, 5 having a V-shaped groove is used.
Although the semiconductor wafer having an inch diameter is used, it is needless to say that the present invention can be applied to not only this but also a semiconductor wafer having various steps or uneven shapes on the surface due to a multilayer wiring structure and a semiconductor wafer having a diameter larger than 5 inches. .

As is apparent from the above detailed description, according to the present invention, since the holding means for holding the base is connected to the rotating means, it can rotate together with the base to prevent the air flow in the closed space. Disturbance can be suppressed. further,
By optimizing the shape of the holding means of the liquid coating device, the film thickness formed on the substrate can be made more uniform, and a film with excellent step coverage can be formed on a semiconductor wafer including steps. can do.

[Brief description of drawings]

FIG. 1 is an assembly diagram showing a main part of a spin coating device according to an embodiment of the present invention.

FIG. 2 is a top view of the sealed chuck shown in FIG.

FIG. 3 is a cross-sectional view taken along the line AA of the sealed chuck shown in FIG.

FIG. 4 is a rear view of the sealed chuck shown in FIG.

5 is an enlarged view of an outer peripheral portion of the closed-type chuck shown in FIG.

FIG. 6 is a plan view of the rear flange shown in FIG.

7 is a cross-sectional view of the seal member shown in FIG.

8 is a cross-sectional view of the packing shown in FIG.

9 is a cross-sectional view of the packing retainer shown in FIG.

FIG. 10 is an assembly diagram showing a configuration of a seal member attaching / detaching mechanism of the spin coating apparatus according to the present embodiment.

11 is a cross-sectional view of the shaft shown in FIG.

12 is a cross-sectional view of the motor housing shown in FIG.

[Explanation of symbols]

11 AC Servo Motor 15 Spin Shaft 30 Sealed Chuck 32 Semiconductor Wafer 33 Vacuum Adsorption Part 35 Slope 36 Peripheral Part 38 Sealing Member 39 Packing 40 Packing Presser 41 Rear Flange 42 Through Hole 43 Recess (Liquid Storage) 60 Linear Cylinder 80 Motor Seal housing 90 Shaft 95 Filter

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Claims (23)

[Claims] 1. A holding means for holding a substrate, a means for dropping a liquid on the substrate, and a rotating means for rotating the substrate, the holding means being coupled to the rotating means and sealed. It is possible to provide a space, and has a fixing part that fixes the base body substantially horizontally in the space, and an outer peripheral part that includes a space defined by an inclined surface that extends obliquely outward from the fixing part. The spin coater is characterized in that the outer peripheral portion includes a space located below the fixed portion. 2. The holding means has a liquid storage part communicating with the inclined surface of the outer peripheral part through a through hole, and the liquid storage part includes a space below the outer peripheral space part. The spin coating apparatus according to claim 1, which is characterized in that. 3. The spin coater according to claim 2, wherein the liquid storage parts are arranged substantially evenly in a circumferential direction of the outer peripheral part. 4. The holding means includes a container means that is coupled to the rotating means and has an opening on one side, and a sealing means that seals the opened one side, thereby providing a sealed space inside. 4. The method according to claim 1, wherein
The spin coater described in 1. 5. The spin coater according to claim 4, wherein the sealing means has an introduction hole for introducing an inert gas into the container means. 6. The substrate processing spin coating apparatus according to claim 4, wherein the spin coating apparatus includes an attachment / detachment mechanism for attaching / detaching the sealing means to / from the container means. 7. The attachment / detachment mechanism includes a mechanism for moving the sealing means upward from the container means, and a mechanism for rotatably supporting the sealing means. Spin coating apparatus for substrate treatment of. 8. The dropping means is movable, and when the sealing means is detached from the container means, the liquid is dropped on the substrate in the container means.
The spin coater described in 1. 9. The holding means includes a closed-type chuck that is coupled to a rotation shaft of a rotation means, and the closed-type chuck has the fixed portion and an outer peripheral portion. The spin coater described in 1. 10. The hermetically sealed chuck has a rear flange coupled to the back surface thereof, and the liquid storage section is formed by the recess formed on the back surface of the chuck and the rear flange. Item 10. The spin coater according to Item 9. 11. The spin coater according to claim 9, wherein a hole for sucking the back surface of the base is formed in the fixing portion of the hermetic chuck. 12. The spin coating apparatus according to claim 1, wherein the base is a semiconductor wafer. 13. The spin coating apparatus according to claim 1, wherein the base is a substrate having a rectangular shape. 14. The spin coater according to claim 13, wherein the base is a liquid crystal substrate. 15. The spin coater according to claim 13, wherein the base is a photomask substrate. 16. A method for applying a liquid onto a base body, wherein the base body is mounted on the base body mounting surface of a hermetically sealed chuck having a space formed outside and below the base body mounting surface and stopped. A liquid is dropped onto the substrate, the opening surface of the hermetically sealed chuck is sealed with a seal member, the substrate is rotated in a hermetically sealed space inside the hermetically sealed chuck, and the liquid is applied onto the substrate. Liquid application method. 17. The liquid applying method includes the steps of positioning a nozzle for dropping a liquid on the opening surface of the hermetically sealed chuck, and retracting the nozzle from the opening surface after the completion of dropping the liquid. The liquid application method according to claim 16. 18. The liquid coating method according to claim 16, wherein the liquid coating method includes a step of injecting an inert gas into the closed space. 19. The liquid coating method according to claim 16, wherein the base is a semiconductor wafer. 20. The liquid application according to claim 19, wherein a step is formed on the surface of the semiconductor wafer, and a planarized polyimide film is formed on the surface of the semiconductor wafer by applying a polyimide resin as the liquid. Method. 21. The liquid coating method according to claim 16, wherein the base is a substrate having a rectangular shape. 22. The spin coater according to claim 21, wherein the base is a liquid crystal substrate. 23. The spin coater according to claim 21, wherein the base is a photomask substrate.