TWI540613B - Coating film formation method,coating film formation device,substrate processing device,and storage medium - Google Patents

Description

Coating film forming method, coating film forming device, substrate processing device, and memory medium

The present invention relates to a technical field of forming a coating film by spin coating.

In the photoresist step of the semiconductor manufacturing step, a treatment liquid is applied to the surface of a semiconductor wafer (hereinafter referred to as a wafer) to form a coating film. The application of the resist liquid is usually performed by spin coating (a method of rotating the wafer to spread the coating liquid onto the entire surface of the wafer), but the film layer is bulged at the peripheral portion of the wafer. At this time, the swelling of the coating film tends to become more pronounced as the viscosity of the resist liquid increases or the target film thickness becomes thicker. The main reason for this is, for example, a decrease in fluidity due to high viscosity.

On the other hand, in order to improve the use efficiency of the wafer, there is a demand for the formation region of the semiconductor device on the wafer to be utilized as much as possible to the peripheral portion. However, when the degree of bulging of the coating film is large, the ridge portion may become different. Can't be used. In addition, partial exposure may be performed before pattern exposure of the peripheral portion of the wafer, and the coating film may be removed by development processing in the subsequent stage without using the peripheral portion as an effective region. At this time, if the coating film is embossed, the exposure does not sufficiently proceed to the bottom of the coating film at the time of peripheral exposure, and as a result, a problem that a good treatment cannot be formed may occur.

Furthermore, we will apply a polyammine solution as a semi-conductive method on a wafer by spin coating. The protective film of the body device or the like, but the viscosity of the polyimide liquid is large, and when it is required to apply a thick film of, for example, a tens of μm grade, we have to review the method of lowering the bulging of the coating film.

Patent Document 1 describes a technique in which a solvent is supplied to a peripheral portion of a wafer to lower the viscosity, and then the wafer is rotated to flatten the peripheral portion. However, when a solvent is supplied to the peripheral portion of the wafer to planarize it, if the rotation speed of the wafer is slow, the peripheral portion may not be sufficiently flattened. On the other hand, if it is rotated at a high speed, bubbles may be mixed in the coating film at the peripheral portion. Although the bubble can be removed by continuously rotating at a high speed, there is a problem that the film thickness of the wafer is thinned at this time.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent No. 2-194873

In view of the above problems, the present invention provides a technique capable of obtaining a coating film having high flatness when a coating film is formed by spin coating on a substrate. Further, a substrate processing method and a substrate processing apparatus which are excellent in peripheral exposure of a substrate by this technique are also provided.

The coating film forming method of the present invention comprises the step of holding a circular substrate horizontally on the substrate holding portion; then, the coating liquid supplied to the central portion of the substrate is diffused by the centrifugal force formed by the rotation of the substrate and coating is formed on the substrate. a step of forming a film; the embossed portion of the coating film formed on the peripheral portion of the substrate in the coating film forming step, and supplying the solvent from the solvent nozzle while the substrate is rotated, and bringing the supply portion of the solvent toward the center of the substrate along the ridge portion a step of moving the portion to thereby lower the viscosity of the raised portion; and subsequently rotating the substrate to remove the raised portion to planarize it.

The coating film forming apparatus of the present invention includes: a substrate holding portion that holds a circular substrate horizontally; a rotating mechanism that rotates the substrate holding portion about a vertical axis; and a coating liquid nozzle that discharges a coating liquid to form a coating film on the substrate; a solvent nozzle that supplies a solvent for lowering the viscosity of the coating film to the substrate; and a control unit that performs a step of supplying a coating liquid to the central portion of the substrate while rotating the substrate, and diffusing the coating liquid by the centrifugal force to the substrate a step of forming a coating film thereon; and in the bulging portion of the coating film formed on the peripheral portion of the substrate in the above step, while the substrate is rotated, the solvent is supplied from the solvent nozzle and the supply portion of the solvent is applied to the substrate along the ridge portion. a step of moving the central portion; and a step of subsequently rotating the substrate to remove the raised portion.

A substrate processing apparatus according to the present invention is a substrate processing apparatus that forms a photosensitive film layer on a circular substrate and develops a substrate after pattern exposure, and includes the above-described coating film forming apparatus; The coating film for removing the peripheral portion of the substrate by the developer is used, and the peripheral film exposure module for exposure is applied to the entire periphery of the coating film on the periphery of the substrate.

The memory medium of the present invention is a memory medium storing a computer program for applying a processing liquid to a substrate that maintains a level to form a coating film forming device for coating a film, the computer program combining the steps to perform the above A method of forming a coating film.

In the present invention, when the substrate is spin-coated, a solvent is supplied to the raised portion of the coating film formed on the peripheral portion of the substrate, and the supply portion of the solvent is moved to the central portion of the substrate. When the substrate is rotated, the more the solvent is supplied toward the periphery, the more the solvent is supplied, and the viscosity is lowered, so that the fluidity of the ridge portion is increased. Therefore, by the cleavage treatment by the rotation of the substrate, it is possible to obtain a coating film having high flatness even at the peripheral portion, and it is difficult to take in air bubbles at the bulging portion when the coating film is flattened. If bubbles are taken in the coating film, it is necessary to rotate at a high speed for a long time in order to remove the bubbles. If the average film thickness of the coating film is inevitably thinner than the predetermined thickness, it is possible to prevent the coating film from being coated according to the present invention. The average film thickness is reduced.

1‧‧‧ cup module

3‧‧‧Solvent nozzle

4‧‧‧ peripheral exposure module

5‧‧‧Nozzle unit

6‧‧‧ gas discharge nozzle

7‧‧‧Solvent nozzle unit

9‧‧‧Control Department

10‧‧‧ Coating unit

12‧‧‧Opening and closing department

13‧‧‧Transportation agencies

21‧‧‧Rotary chuck

22‧‧‧Rotary axis

23‧‧‧Rotating mechanism

24‧‧‧ cups

25‧‧‧Draining line

26‧‧‧Exhaust line

27‧‧‧Transfer arm

30‧‧‧Exporting

31‧‧‧ Arms

33‧‧‧Mobile

34‧‧‧Solvent supply mechanism

35‧‧‧Guidance track

36‧‧‧Standby station

37‧‧‧Supply tube

38‧‧‧resist solution

39‧‧‧Uplifting

41‧‧‧Rotating table

42‧‧‧Exposure Department

51‧‧‧Diluent nozzle

52‧‧‧resist nozzle

53‧‧‧Diluent supply mechanism

54‧‧‧resist liquid supply mechanism

55‧‧‧ Arms

56‧‧‧Standby station

57‧‧‧Supply tube

58‧‧‧Supply tube

59‧‧‧Mobile

60‧‧‧Guidance track

61‧‧‧ gas supply

W‧‧‧ wafer

P‧‧‧ position

C‧‧‧匣 box

B1~B6‧‧‧1st to 6th block

S1‧‧‧Transporting block

S2‧‧‧ processing block

S3‧‧‧ interface block

S4‧‧‧ exposure station

U1~U10‧‧‧ shed unit

R3‧‧‧Handling area

A3‧‧‧ main arm

BCT‧‧‧Anti-reflection film formation treatment

COT‧‧‧resist film formation treatment

DEV‧‧‧Development

Fig. 1 is a plan view of a substrate processing apparatus including a coating film forming apparatus according to an embodiment of the present invention.

Fig. 2 is a perspective view of a substrate processing apparatus including a coating film forming apparatus according to an embodiment of the present invention.

Fig. 3 is a structural view showing a coating film forming apparatus according to an embodiment of the present invention.

Fig. 4 is a perspective view showing a part of a coating film forming apparatus according to an embodiment of the present invention.

Fig. 5 is an explanatory view showing a step of forming a coating film.

FIG. 6 is an explanatory view showing a state of a peripheral portion of the wafer after the formation of the coating film.

FIG. 7 is an explanatory view showing a step of flattening a peripheral portion of a substrate of the coating film forming apparatus according to the embodiment of the present invention.

FIG. 8 is an explanatory view showing a transition of a discharge position of a solvent in a flattening step of a peripheral portion of a substrate of a coating film forming apparatus according to an embodiment of the present invention.

FIG. 9 is an explanatory view showing a step of flattening a peripheral portion of a substrate of the coating film forming apparatus according to the embodiment of the present invention.

FIG. 10 is an explanatory view showing a step of flattening a peripheral portion of a substrate of a coating film forming apparatus according to an embodiment of the present invention.

FIG. 11 is an explanatory view showing a step of flattening a peripheral portion of a substrate of a coating film forming apparatus according to an embodiment of the present invention.

Fig. 12 is an explanatory view showing a peripheral exposure process of the substrate.

FIG. 13 is an explanatory view showing a transition of a discharge position of a solvent in a step of flattening a peripheral portion of a substrate of a coating film forming apparatus according to another embodiment.

FIG. 14 is an explanatory view showing another example of the step of flattening the peripheral portion of the substrate of the coating film forming apparatus.

Fig. 15 is a characteristic view showing a coating film forming apparatus of the embodiment.

Fig. 16 is a schematic view showing a state of a peripheral portion of a substrate which has been subjected to the treatment using the substrate processing apparatus of the embodiment.

A substrate processing apparatus including a coating film forming apparatus according to an embodiment of the present invention will be described with reference to Figs. 1 and 2 . This device is constructed by linearly connecting the transfer block S1, the processing block S2, and the interface block S3. The interface block S3 is further connected to the exposure station S4.

The transfer block S1 has a function of loading or unloading the cassette C including a plurality of circular substrates (that is, the wafer W) of the same batch, and includes a mounting table of the cassette C, the opening and closing unit 12, and The opening and closing unit 12 conveys the transport mechanism 13 for the wafer W from the cassette C.

The processing block S2 is formed by sequentially stacking the first to sixth unit blocks B1 to B6 for liquid processing of the wafer W from bottom to top, and each of the unit blocks B1 to B6 has substantially the same structure. The letters attached to the respective unit blocks B1 to B6 in Fig. 2 represent the treatment type, BCT represents the anti-reflection film formation process, COT represents the resist film formation process, and DEV represents the development process.

The unit block B3 includes a main arm A3 that moves from the transfer block S1 to the linear conveyance region R3 of the interface block S3, a coating unit 10 that is a coating film forming device, and a wafer W that is heated and cooled. The shed unit U1 to U5 of the thermal module used; and the shed unit U6 including the peripheral exposure module 4. The peripheral exposure module 4 is a member for exposing a peripheral portion of the wafer W after the resist coating.

On the side of the transfer block S1 of the transport area R3, a shed unit U7 composed of a plurality of modules stacked on each other is provided. The transfer of the wafer W between the transport mechanism 13 and the main arm A3 is performed through the module of the shed unit U7 and the transfer arm 27.

The interface block S3 is a member that transfers the wafer W between the processing block S2 and the exposure station S4, and has a plurality of modules U8, U9, and U10 stacked on each other.

In the substrate processing apparatus, the wafer W transported by the cassette C is transported to the processing block S2 by the transport mechanism 13, and the (BCT) layer B1 (B2) → resist film formation (COT) layer is formed in accordance with the anti-reflection film. The sequential conveyance of B3 (B4) is carried out to the exposure station S4 via the interface block S3 to perform exposure processing. The exposed wafer W is transported to the developing (DEV) layer B5 (B6) via the interface block S3 for development processing, and then returned to the cassette C of the transfer block S1 via the shed unit U7 and the transport mechanism 13.

The coating unit 10, as shown in FIG. 1, for example, has a cup-shaped module 1 arranged side by side in a row; A nozzle unit 5 that is shared by the plurality of cup-shaped modules 1 and that moves freely in the side-by-side direction of the cup-shaped module 1; and a solvent nozzle unit 7 that is provided in each of the cup-shaped modules.

As shown in FIGS. 3 and 4, the cup-shaped module 1 has a substrate holding portion for holding the center portion of the back surface of the wafer W and holding it horizontally, that is, the rotary chuck 21, and the rotary chuck 21 is transmitted through the rotary shaft 22 and The rotating mechanism 23 is connected. A cup-shaped body (in detail, a cup-shaped assembly) 24 having an opening on the upper side is provided around the rotary chuck 21 so as to surround the wafer W on the rotary chuck 21 . The cup 24 blocks the solvent or the like ejected from the wafer W, and is discharged from the lower drain line 25 while being exhausted from the lower exhaust line 26 so that the liquid mist does not scatter in the process gas atmosphere. .

As shown in FIG. 4, the nozzle unit 5 uses a moving mechanism including an arm portion 55, a moving body 59, a lifting mechanism (not shown), and a guide rail 60, and a discharge position and a cup above the center portion of the wafer W. The standby station 56 other than 24 moves between.

A diluent nozzle 51 and a resist nozzle 52 as a coating liquid nozzle are provided at a tip end portion of the nozzle unit 5. The diluent nozzle 51 and the resist nozzle 52 are connected to the diluent supply mechanism 53 and the resist liquid supply mechanism 54 via the supply pipes 57 and 58, respectively. The diluent supply mechanism 53 and the resist liquid supply mechanism 54 include a device such as a pump, a valve, and a filter, and discharge a predetermined amount of diluent and resist from the tips of the diluent nozzle 51 and the resist nozzle 52, respectively. liquid. In the embodiment of the present invention, for example, a resist liquid having a high viscosity of more than 100 cP is used as the resist liquid for forming a coating film, and a coating having a film thickness of about 80 μm is formed by a resist coating step to be described later. membrane.

Next, the solvent nozzle 3 included in the solvent nozzle unit 7 will be described. The solvent nozzle 3 supplies a solvent to a peripheral portion of the wafer W after the coating film is formed, for example, propylene glycol monomethyl ether (PGME) and propylene glycol monomethyl ether acetate (PGMEA). 7:3 mixture. Here, the terms "diluent" and "solvent" are used, and the diluent nozzle 51 of the nozzle unit 5 is an organic solvent (i.e., a diluent) for pre-wetting the wafer W before the resist is applied. member. Further, the solvent nozzle 3 is a member that ejects an organic solvent (that is, a diluent) after the resist W is applied to the wafer W. In the present specification, in order to make the description easier to understand, the organic solvent discharged from the diluent nozzle 51 is inexpensive. In the phrase "diluent", the term "solvent" is used for the organic solvent discharged from the solvent nozzle 3.

The solvent nozzle 3 is connected to the solvent supply mechanism 34 via the supply pipe 37, and a predetermined amount of solvent can be discharged from the tip end of the solvent nozzle 3 by means of a pump, a filter, a valve or the like. The solvent nozzle 3 is disposed at an obliquely downward angle, and when the solvent is supplied to the peripheral portion of the wafer W, the discharge port 30 discharges the solvent in a direction radially outward of the wafer W.

The solvent nozzle 3 is supported by the arm portion 31, which is provided by the support portion, and the arm portion 31 is provided so as to be lifted and lowered by the moving body 33 by a lifting mechanism not shown. The movable body 33 is moved so as to be guided by the member such as the ball screw mechanism on the guide rail 35, so that the solvent nozzle 3 can move between the standby station 36 and the upper region of the peripheral portion of the wafer W. The moving body 33 can be adjusted in its horizontal position, for example, at intervals of 2 mm. Therefore, the moving body 33 is a supply position changing mechanism that adjusts the horizontal position of the solvent nozzle 3 and the position at which the solvent is discharged on the surface of the wafer W by, for example, 2 mm intervals.

The substrate processing apparatus includes a control unit 9 composed of, for example, a computer. The control unit 9 has a program storage unit that stores a program for controlling the overall operation of the substrate processing device. Regarding the program, when focusing on the coating unit 10, the transfer of the wafer W between the main arm A3 and the rotary chuck 21, the rotation of the rotary chuck 21, the movement of the resist liquid or the solvent nozzle, or The order is supplied in a sequential manner and the program is stored. The program is stored and installed in the control unit 9 by a memory medium such as a floppy disk, a compact disk, a hard disk, an MO (magnetic disk), a memory card, or the like.

Next, the operation of the above-described embodiment will be described. Since the flow of the entire wafer W in the substrate processing apparatus has been described, the operation of the coating unit 10 corresponding to the coating film forming apparatus of the present invention will be described.

The wafer W is transferred from the main arm A3 (A4) of the resist film formation (COT) layer B3 (B4) to the spin chuck 21, and the wafer W is held horizontal by the spin chuck 21. Next, the nozzle unit 5 is moved to the upper portion of the wafer W while the wafer W is stopped, or the rotating mechanism 23 rotates the wafer W at a low speed, and the wafer W is fed from the diluent nozzle 51. The solvent is supplied to the center. Crystal The entire surface of the circle W is in a state of being wetted by the diluent (pre-wet), and the resist liquid is more likely to diffuse. Next, as shown in FIG. 5, the resist liquid 38 is discharged from the resist nozzle 52 to the wafer W. The resist liquid 38 is diffused on the surface of the wafer W by the centrifugal force generated by the rotation of the wafer W to form a coating film. At this time, in the resist liquid diffused to the entire surface of the wafer W, because of the surface tension between it and the periphery of the wafer W, as shown in FIG. 6, a film thickness ridge portion is formed at the peripheral portion of the coating film. 39.

The planarization step of the peripheral portion of the wafer W after the coating film (resist film) is formed on the wafer W by spin coating as described above will be described with reference to FIGS. 7 to 11 . When the coating film has sufficient fluidity, a solvent is supplied to the peripheral portion thereof. The nozzle unit 5 is retracted from the center of the wafer W to the standby station 56, and the solvent nozzle 3 is moved from the standby station 36 to the position P above the wafer W shown by the broken line in Fig. 7 . At this time, the discharge port 30 of the solvent nozzle 3 discharges the solvent from the solvent nozzle 3 at the position P toward the radially outer side of the wafer W, and the solvent discharge position is 1 mm outside the periphery of the wafer W. s position. The "discharge position of the solvent" indicates the position of the solvent discharged from the solvent nozzle 3 on the surface of the wafer W or on the extension line of the surface.

Then, the solvent nozzle 3 is moved toward the center portion of the wafer W at a speed of 1 mm/sec as shown in FIG. 7, and the solvent discharge position is located at a distance of, for example, 2 mm from the periphery of the wafer W. (the solid line position of Fig. 7) is stopped. Thereafter, the solvent nozzle 3 was stopped at this position for 5 seconds and the solvent was continuously supplied.

Fig. 8 is a view showing a moving pattern of the solvent nozzle 3 as a moving pattern of a solvent, the solvent nozzle 3, and then discharging the solvent, and approaching the center portion of the wafer W, for example, moving in a stepwise manner every 2 mm, at a distance Each of the peripheral edges of the wafer W of 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm was stopped for 5 seconds, and then moved to the original position of P while the solvent was continuously discharged (see FIG. 7). When the solvent nozzle 3 moves along the moving pattern, the wafer W is rotated at, for example, 100 rpm.

7, 9, and 10 are state diagrams showing the solvent nozzle 3 and the swelled portion 39 in a part of the moving pattern shown in Fig. 8. With the movement of the solvent nozzle 3, solvent supply, from the wafer W The peripheral side is sequentially infiltrated into the raised portion 39 of the coating film. In addition, in FIG. 7, FIG. 9, and FIG. 10, the solvent supply part of the surface of the wafer W is attached with an access point.

After the supply of the solvent to the peripheral portion of the wafer W was completed, the wafer W was rotated at a rotation speed of 100 rpm for 5 seconds. Thereafter, the rotational speed of the wafer W is raised to 300 rpm for about 5 seconds, and the back surface cleaning step of the wafer W can be performed, for example, while rotating at 300 rpm for 5 seconds.

Next, the rotational speed of the wafer W is raised to, for example, 2000 rpm, and maintained for 1 second. The ridge portion 39 of the resist film whose viscosity is lowered and the fluidity is increased due to the supply of the solvent, as shown in Fig. 11, is elongated and ejected in the outer peripheral direction by the high-speed rotation of 2000 rpm.

When the viscosity of the coating film at the peripheral portion of the wafer W is uneven due to the drying of the resist film on the wafer W, for example, if the wafer W is rotated at a high speed of 1000 rpm or more, the wafer is wafer. The diffusion pattern of the resist film at the peripheral portion of W becomes uneven, because the turbulent flow occurring at the peripheral portion of the wafer W makes it easy to take in the resist film, and further in the resist film. Create bubbles. The solvent supplied to the wafer W as described above is gradually diffused to a portion outside the supplied portion due to the centrifugal force generated by the rotation of the wafer W. Therefore, when the supply position of the solvent is supplied from the peripheral edge portion of the wafer W toward the center portion as described above, the portion having a thick outer film thickness receives more solvent than the inner portion. Supply. The resist film on the wafer W has a larger amount of solvent to be supplied to the outer region of the peripheral portion of the wafer W, and the viscosity is lowered. Therefore, the fluidity becomes better at the peripheral portion. Therefore, when the above-described treatment is performed, the wafer W is rotated at a high speed of, for example, 2000 rpm after the supply of the solvent, and even if the peripheral portion is turbulent, the portion of the resist film having a non-uniform viscosity at the peripheral portion is less. The film is diffused with high uniformity, which prevents airflow from entering the resist film, thereby reducing the occurrence of bubbles.

Further, when the supply position of the solvent is moved from the inner region of the wafer W to the outer region, the solvent supply region gradually becomes the outer region and is reduced. Therefore, in the region near the inner side of the peripheral portion of the wafer W, it is roughly the case that only the supply of the solvent is initially supplied to the solvent supply. Therefore, in the region near the inner side of the peripheral portion of the wafer W, drying is rapidly performed after the solvent is supplied. Therefore, after the supply of the solvent is completed, the wafer W is rotated at 2000 rpm to remove the raised portion 39 of the peripheral portion, and the fluidity of the region near the inner side of the peripheral portion of the wafer W is lowered, and the peripheral portion of the wafer W is lowered. It cannot spread with high uniformity.

According to the above-described embodiment, when the wafer W is spin-coated, a solvent is supplied to the raised portion 39 of the coating film formed on the peripheral portion of the wafer W, and the supply portion of the solvent is moved toward the center portion of the wafer W. . When the wafer W is rotated, the more the solvent is supplied to the periphery of the coating film, the lower the viscosity, and the fluidity of the ridge portion is increased. Therefore, the coating process by the rotation of the wafer W can obtain a coating film having high flatness even at the peripheral portion, and at the same time, it is not easy to take in air bubbles when the coating film is flattened. If the bubbles enter the coating film, it is necessary to perform high-speed rotation for a long time in order to remove the bubbles. If the average film thickness of the coating film is inevitably thinner than the predetermined thickness, the average film of the coating film can be prevented according to the present invention. The thickness is reduced.

The coating film forming apparatus described above is particularly effective when a coating liquid having a viscosity of 100 cP or more is used. Further, when the target film thickness of the coating film is 1 μm or more, the ridge of the film layer is remarkable, and the present invention is particularly effective at this time. Further, the rotation speed of the wafer W when the ridge portion 39 is removed is preferably 1000 rpm or more.

Here, the correlation between the planarization treatment of the raised portion 39 of the foregoing resist film and the peripheral exposure of the wafer W will be described. In the processing procedure for forming the resist pattern, exposure may be performed over the entire circumference of the peripheral portion of the wafer W, for example, a width of 1.5 mm from the periphery, and the peripheral portion may be formed with a developing solution at the subsequent development processing of the step. The resist film is removed, and the wafer W is also peripherally exposed in the above-described embodiment. FIG. 12 is a schematic view of the peripheral exposure module 4. For example, ultraviolet rays are irradiated to the peripheral portion of the wafer W horizontally held by the turntable 41 by the exposure portion 42. The wafer W is rotated about the vertical axis in a state where the peripheral portion is irradiated with ultraviolet rays, and the predetermined width of the peripheral portion of the circular wafer W is exposed. If the raised portion 39 of the resist film exists in the peripheral portion of the wafer W, and the raised portion 39 is spread to the side closer to the center of the wafer W than the peripheral exposed region, the portion cannot be used as the formation region of the device. .

Further, when the peripheral exposure of the wafer W is performed, if the peripheral exposure process is performed in the case where the raised portion 39 of the resist film is present in the peripheral exposed region, the exposed portion 39 of the film thickness cannot be sufficiently exposed. Will become a residue, when transported to, for example, the exposure station S4, Parts of the residue may peel off and become debris. Further, if the peripheral exposure treatment is carried out until the residue can be sufficiently removed, the exposure processing takes a long time and affects the productivity.

According to the method of the above-described embodiment, the uniformity of the film thickness in the region where the peripheral exposure processing of the wafer W is performed is high, so that uneven processing is less likely to occur in the peripheral exposure processing, and the resist is not left. The residue of the membrane. Further, since the thickness of the film is small, the peripheral exposure processing time can be set to be short, so that the productivity can be prevented from being lowered.

Further, in the above-described embodiment, when the cross section of the resist film is observed, the top of the raised portion 39 sandwiching the resist film is discharged from the peripheral portion of the wafer W toward the center portion side of the wafer. The position is intermittently moved and stopped at five positions, but the moving pattern of the discharge position is not limited to this example. For example, if the width of the raised portion is approximately 12 mm, the discharge position may be intermittently moved from the periphery of the wafer W, for example, every 4 mm, as in the movement pattern of the solvent shown by the solid line in FIG. The stop position is three positions (positions of 4 mm, 8 mm, and 12 mm from the circumference), or, for example, intermittently moving every 6 mm to make the stop position two positions. Alternatively, as shown by a dotted line in FIG. 13, the solvent may be ejected while continuously moving from the periphery of the wafer W to a position of 12 mm. Further, the discharge port 30 of the solvent nozzle 3 may be directed downward (the state in which the axis of the discharge port 30 is orthogonal to the wafer W). Although the direction of the discharge port 30 is not excluded from the center side of the wafer W, it is preferable that the direction toward the center of the wafer W is directed downward or toward the peripheral side of the wafer W.

Further, in the present invention, as shown in FIG. 14, a gas such as nitrogen gas or dry air may be discharged to the radially outer side of the wafer W on the peripheral portion of the wafer W. For example, a gas discharge nozzle 6 that is connected to the gas supply source 61 and discharges gas from the tip end is provided, and after supplying a solvent to the peripheral portion of the wafer W and then rotating it at, for example, 2000 rpm, the peripheral portion of the wafer W is wafer W. The gas is blown to the outside in the radial direction, whereby the coating film on the peripheral portion of the wafer W is relatively easily flowed outward, and it is easier to flatten it. The gas discharge nozzle 6 may be an independent nozzle or may be provided together with the solvent nozzle 3.

The coating liquid used in the present invention is not limited to the resist liquid, and may be, for example, poly Asia. A guanamine solution which forms a polyimide film as a protective film for a semiconductor integrated circuit component. Since the polyimide liquid has a high viscosity of, for example, 500 cP, the coating film on the peripheral portion of the wafer W during the spin coating tends to be thick, and therefore the present invention is quite effective.

[Example 1]

In order to evaluate the present invention, the coating unit 10 according to the embodiment of the present invention is used to perform flattening treatment of the coating film at the peripheral portion of the wafer, and to measure the film thickness after drying. In any of the examples and the comparative examples, 15 ml of a resist having a viscosity of 6000 cP was applied to the wafer W (diameter: 300 mm), and the film was rotated at 370 rpm for 55 seconds to form an average film thickness of 80 μm. Film formation treatment. Further, a 7:3 mixture of PGME and PGMEA was used for the solvent supplied to the peripheral portion of the wafer W.

(Example 1-1)

The solvent is ejected from the solvent nozzle 3, and when the discharge position is intermittently moved from the periphery of the wafer W, the stop position of the discharge position is set to a position away from the peripheral edges 6, 8, and 10 mm, and the solvent nozzle 3 is moved in this order. During this time, the wafer W was rotated at 100 rpm.

(Example 1-2)

The discharge position of the solvent was set to a position 4, 6, 8, and 10 mm from the periphery W of the wafer W, and the same as Example 1-1.

(Example 1-3)

The discharge position of the solvent was set to a position spaced apart from the periphery 2, 4, 6, 8, and 10 mm of the wafer W, and the same as in Example 1-1.

(Comparative Example 1)

The solvent discharge position was set to a position 4, 6, 8, and 10 mm from the periphery of the wafer W, and the solvent nozzle 3 was moved, and then the solvent was supplied.

[validation experiment]

The processes of Examples 1-1 to 1-3 and Comparative Example 1 were carried out while rotating at 100 rpm, and then rotated at 1000 rpm for 2 seconds to obtain a film thickness in the vicinity of the peripheral portion of the wafer W. Fig. 15 is a characteristic diagram showing the result, in which the horizontal axis represents the distance from the center of the wafer W, and the vertical axis represents the thickness of the coating film of the wafer W.

According to Fig. 15, in Comparative Example 1, the film thickness at a position of 143 mm from the center of the wafer W reached a maximum value of 95 μm. Further, the thickness of the coating film in the range of 138 mm from the center of the wafer W was within 80 ± 6 μm. On the other hand, in Example 1-1, the film thickness at a position of 147 mm from the center of the wafer W was 87 μm at the maximum. Further, the thickness of the coating film in the range of 145 mm from the center of the wafer W was within 80 ± 6 μm. In Example 1-2, the maximum film thickness was 81 μm, and the thickness of the coating film in the range of 147 mm from the center of the wafer W was within 80 ± 6 μm. In Example 1-3, the maximum film thickness was 80 μm, and the thickness of the coating film in the range of 146 mm from the center of the wafer W was within 80 ± 6 μm.

Further, in Comparative Example 1 and Example 1-3, after the wafer W was rotated at 100 rpm and subjected to respective treatments, the wafer W was rotated at a rotation speed of 1000 rpm and 2000 rpm, and the peripheral portion of the wafer W after the drying treatment was inspected. Whether or not bubbles occur. Table 1 shows the results of Comparative Example 1 and Examples 1-3.

As shown in Table 1, the occurrence of bubbles was not observed in Comparative Example 1 and Example 1-3 in which the rotation speed was set to 1000 rpm. On the other hand, in Comparative Example 1 and Example 1-3 in which the rotation speed was set to 2000 rpm, Comparative Example 1 generated bubbles at the peripheral portion, and Example 1-3 did not observe the occurrence of bubbles.

The film thickness of the coating film of the example was improved by 60 to 100% as compared with the comparative example. Further, the film thickness of the coating film was also expanded by about 6% in the range of 80 ± 6 μm. Further, even when the air is rotated at a high speed, air bubbles are less likely to occur, so that it is difficult to cause an unusable area on the peripheral portion of the wafer W. Further, the rotational speed of the wafer W in the step of supplying the solvent is preferably about 100 rpm. When the coating unit 10 of the embodiment of the present invention is used, the peripheral portion of the wafer W can be flattened, and bubbles can be prevented from occurring at the peripheral portion of the wafer W.

[Example 2]

In order to verify the efficacy of the substrate processing apparatus including the coating film forming apparatus of the embodiment of the present invention, the following experiment was conducted.

In the coating film forming treatment, a resist having a viscosity of 520 cP was applied, and the wafer W was rotated at 800 rpm for 25 seconds to have a film thickness of 20 μm. In Comparative Example 2, the coating film forming process was performed without supplying a solvent to the peripheral portion of the wafer W, and the wafer W rotated at a speed of one rotation at 8 seconds was subjected to a peripheral exposure process of 375 seconds. Further, after applying the same resist liquid, a solvent was supplied to the peripheral portion under the conditions of Example 1-1, and the mixture was rotated at 1000 rpm to planarize the peripheral portion. Thereafter, the wafer W rotated at a speed of one rotation at eight seconds was subjected to peripheral exposure processing for 80 seconds, 120 seconds, and 160 seconds, and was set to Examples 2-1, 2-2, and 2-3, respectively.

[validation experiment]

16 is a schematic view showing a pattern of a peripheral portion of the wafer W after the treatment of each of Comparative Example 2, Examples 2-1, 2-2, and 2-3, obliquely from the upper side, and shows a comparison from Comparative Example 2 and The position of the slit of the peripheral portion of the wafer W of each of the examples is in a state of a portion of 0°, 60°, 120°, 180°, 240°, and 300°. Further, the resist film in the region where the exposure treatment was not performed was attached with a diagonal line, and the residue of the resist film after the peripheral exposure treatment was indicated by hatching of dots.

In Comparative Example 2, although the peripheral exposure treatment was performed for 375 seconds, the exposure film was not sufficiently exposed, and the resist film remained as a residue in a wide range. On the other hand, in Example 2-1, although a very small amount of residue was observed at a portion of 300°, in Example 2-2 and Example 2-3, the resist film did not become a residue at the peripheral portion. Remained. When the peripheral portion of the wafer W is flattened by the liquid processing method according to the embodiment of the present invention, the peripheral portion of the wafer W can be reliably removed even in the short-time peripheral exposure processing of about 120 seconds. Resist.

1‧‧‧ cup module

3‧‧‧Solvent nozzle

5‧‧‧Nozzle unit

7‧‧‧Solvent nozzle unit

9‧‧‧Control Department

21‧‧‧Rotary clamp

22‧‧‧Rotary axis

23‧‧‧Rotating mechanism

24‧‧‧ cups

25‧‧‧Draining line

26‧‧‧Exhaust line

30‧‧‧Exporting

31‧‧‧ Arms

33‧‧‧Mobile

34‧‧‧Solvent supply mechanism

37‧‧‧Supply tube

51‧‧‧Diluent nozzle

52‧‧‧resist nozzle

53‧‧‧Diluent supply mechanism

54‧‧‧resist liquid supply mechanism

57‧‧‧Supply tube

58‧‧‧Supply tube

W‧‧‧ wafer

Claims (9)

A coating film forming method comprising: a substrate holding step of horizontally holding a circular substrate on a substrate holding portion; and a first step of, after the substrate holding step, a center of the substrate by a centrifugal force generated by rotation of the substrate The coating liquid supplied from the portion is diffused to form a coating film on the substrate. In the second step, the embossed portion of the coating film formed on the peripheral portion of the substrate by the first step is rotated from the solvent in the state in which the substrate is rotated. The nozzle supplies a solvent; and a third step, wherein the number of revolutions of the substrate is raised to a number of revolutions of 1000 rpm or more higher than the number of revolutions in the second step, and the raised portion is stripped for planarization; The second step is a step of moving the supply portion of the solvent from the outer side of the raised portion toward the central portion of the substrate until the inner side of the raised portion, and the viscosity of the raised portion in a state where the raised portion remains. decline. The coating film forming method according to claim 1, wherein in the second step, the discharge port of the solvent nozzle faces downward or in a direction radially outward of the substrate. The coating film forming method according to claim 1 or 2, wherein the coating liquid has a viscosity of 100 cp or more. The coating film forming method according to claim 1 or 2, wherein in the second step, the rotation speed of the substrate is 100 rpm or more and 300 rpm or less. A substrate processing method for forming a coating film of a photosensitive film layer on a circular substrate, and developing a substrate subjected to pattern exposure, comprising: applying a coating liquid for producing a photosensitive film layer, and implementing the patent application number 1 And a step of forming a coating film of two or more; and, in order to remove the coating film of the peripheral portion of the substrate by the developer, after the substrate is rotated to flatten the raised portion, the coating film on the peripheral portion of the substrate is spread over The step of exposing it all week. A memory medium storing a computer program for applying a processing liquid to a substrate to maintain a level to form a coating film forming device, wherein the memory medium is characterized in that the computer program includes a patent application The step group of the coating film forming method of the first or second aspect. A coating film forming apparatus comprising: a substrate holding portion that holds a circular substrate horizontal; a rotating mechanism that rotates the substrate holding portion about a vertical axis; and a coating liquid nozzle that discharges a coating liquid to form a coating film on the substrate; a solvent a nozzle for supplying a solvent for lowering the viscosity of the coating film to the substrate, and a control unit for controlling the substrate holding portion, the rotating mechanism, the coating liquid nozzle, and the solvent nozzle to perform the following process a coating film forming method: a first step of supplying a coating liquid to a central portion of a substrate by the coating liquid nozzle, and rotating the substrate by the rotating mechanism to diffuse the coating liquid by centrifugal force to form a coating film on the substrate; In the second step, the embossed portion of the coating film formed on the peripheral portion of the substrate in the first program is supplied with the solvent by the solvent nozzle while the substrate is rotated by the rotating mechanism, and the solvent is supplied at the same time. The portion moves from the outer side of the raised portion toward the central portion of the substrate until the inner side of the raised portion, while the ridge remains a state in which the viscosity of the raised portion is lowered; and a third procedure, which then causes the number of revolutions of the substrate to rise to a number of revolutions of 1000 rpm or more higher than the number of revolutions when the second program is executed, so that the raised portion is甩 甩 to flatten. The coating film forming apparatus according to claim 7, wherein the discharge port of the solvent nozzle faces downward or toward the radially outer side of the substrate. A substrate processing apparatus which forms a photosensitive film layer on a circular substrate and develops a substrate subjected to pattern exposure, and is characterized by comprising: a coating film forming device according to claim 7 or 8; In the peripheral exposure module, in order to remove the coating film at the peripheral portion of the substrate by the developer, the coating film on the peripheral portion of the substrate is exposed over the entire circumference.