JP2003007595A - Developing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a conventional developing method of resist that a resist component dissolved into developing liquid is deposited when rinse liquid is dripped to produce a filmy foreign matter adhering to a wafer surface and that the foreign matter causes a pattern defect when it adheres onto the pattern. SOLUTION: In the inventive developing method, developing liquid dissolving resist is removed from a semiconductor wafer by shaking off the developing liquid without performing a rinse process following to a paddle developing process. Since the rinse process is not performed, the concentration of the developing liquid is prevented from being lowered by the rinse liquid to cause deposition/aggregation of the resist component dissolving into the developing liquid on the wafer surface. Furthermore, the generation of the filmy foreign matter can be reduced at the time of development by repeating the development process and the rinse process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and more particularly to a developing method used for a photoresist developing process on a semiconductor wafer (hereinafter simply referred to as a wafer).

[0002]

2. Description of the Related Art In recent years, design rules of semiconductor devices have been miniaturized, and in the photoresist developing process,
Defects on the surface of a semiconductor device having a size that has not been a problem in the past have also been fatally affected.

A conventional photoresist developing method will be described with reference to the drawings. FIG. 7 is a flow chart showing steps of a photoresist developing method, and FIG. 8 is a schematic diagram showing a developing method which is used as standard among conventional developing methods.

In FIG. 7, a first step is a developing liquid drop step 11, and as shown in FIG. 8A, a developer discharge nozzle onto a resist 2 formed in a film shape on the surface of a wafer 1. The developer 4 is dripped from 3. At this time, the wafer 1 is attracted by the spin chuck 5 and is rotating.
As a result, the developer 4 supplied onto the resist 2 is spread from the central portion of the wafer 1 in the peripheral direction.

Next, in FIG. 7, the second step is a developing step 12, and as shown in FIG. 8B, the rotation of the wafer 1 is stopped and the developing solution 4 spread over the entire surface of the wafer 1. Is held on the resist 2 by the surface tension. As a result, the development reaction of the resist 2 with the developer 4 proceeds.

Next, in FIG. 7, the third step is a rinse step 13, and as shown in FIG. 8C, while the wafer 1 is being rotated by the spin chuck 5, the rinse liquid is discharged from the rinse liquid discharge nozzle 6. A rinsing liquid 7 is dropped on the liquid 1.
The dropped rinse solution 7 rinses away the developer 4 to clean the wafer 1.

Finally, in FIG. 7, the fourth step is a rinse liquid shaking step 14, and the fifth step is a drying step 1.
As shown in FIG. 8D, the wafer 1 is rotated and the rinse liquid 7 is shaken off to spin-dry the resist 2 patterned on the surface of the wafer 1.

[0008]

However, in the above-described structure, the developing solution 4 on the wafer surface is removed by the rinsing solution 7 in the rinsing step 13. At this time, the rinsing solution 7 is added to the developing solution 4. Is dropped, the concentration of the developing solution 4 is lowered, the resist component dissolved in the developing solution 4 is deposited, and a thin film-like foreign substance is attached to the surface of the wafer 1. If the foreign matter adheres to the pattern, it causes a pattern defect.

In view of the above problems, the present invention provides a developing method for reducing pattern defects caused by precipitation of resist components.

[0010]

SUMMARY OF THE INVENTION A developing method according to the present invention includes a resist applied by developing a resist applied on the surface of a wafer and then shaking off the developing solution before a rinsing step of washing away the developing solution. The developer is removed from the wafer.

Furthermore, after the developing solution has been shaken off, the second developing solution is dropped onto the wafer to dissolve the resist residue remaining after the developing solution is shaken off, and the resist residual component is deposited with a rinse solution. It is provided with a configuration in which the developing solution is washed out without any action.

Furthermore, the steps after the second step of dropping the developing solution onto the wafer are repeated.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A resist developing method according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a flow chart showing steps of a photoresist developing method of the present invention, and FIGS. 2A to 2E are schematic diagrams of process steps showing a resist developing method according to an embodiment of the present invention. is there.

In FIG. 1, the first step is a developing liquid drop step 21, and as shown in FIG. 2A, the developing solution is discharged onto the resist 2 formed in a film shape on the surface of the wafer 1. The developing solution 4 is discharged from the nozzle 3. At this time, the wafer 1 is attracted by the spin chuck 5 and is rotating. As a result, the developing solution 4 supplied onto the resist 2 is spread from the central portion of the wafer 1 in the peripheral direction.

Next, in FIG. 1, the second step is a developing step 22. As shown in FIG. 2B, the rotation of the wafer 1 is stopped and the developing solution 4 spread on the entire surface of the wafer 1 is removed. The paddle state is maintained on the resist 2 by the surface tension. As a result, the development reaction of the resist 2 with the developer 4 proceeds. At this time, the time during which the developing solution 4 is held in the paddle state requires the time for the developing solution 4 to reach the wafer 1 under the resist 2 (development end point), that is, the developing time for enabling the resist pattern formation. Become. This is a time period during which most of the resist 2 in the exposed portion that dissolves in the developer 4 is dissolved. The paddle time at this time varies depending on the type of resist.

Next, in FIG. 1, the third step is a developer shaking-off step 23, in which the wafer 1 is rotated as shown in FIG. 2C, and the developer 4 and the resist dissolved in the developer 4 are rotated. Shake 2 from wafer 1. At this time, the next step is performed while the remaining resist 2 is not dried.

Next, referring to FIG. 1, the fourth step is a rinse step 24, and the fifth step is a rinse solution shaking step 2
5, the rinse liquid 7 is discharged onto the wafer 1 from the rinse liquid discharge nozzle 6 while the wafer 1 is rotated by the spin chuck 5 as shown in FIG. 2D. The wafer 1 is washed by washing away the developing solution 4 containing the resist in which the discharged rinse solution 7 remains. Here, pure water that is deionized water is used as the rinse liquid. Since the developing solution 4 and the resist 2 dissolved in the developing solution 4 have been shaken off in the previous developing solution shaking-off step 23, even if the developing solution concentration is lowered by mixing the rinse solution 7 and the developing solution 4,
Since the situation of the resist 2 dissolved in the remaining developing solution 4 is greatly reduced, the generation of insolubilized particles of the resist 2 deposited can be greatly reduced.

Finally, in FIG. 1, the sixth step is a drying step 26, which is performed by rotating the wafer 1 and shaking off the rinse liquid 7 as shown in FIG.
The resist 2 patterned on the surface of the wafer 1 is spin dried.

FIG. 3 is a characteristic diagram showing the relationship between the number of pattern defects generated by the developing method of the present invention and the conventional developing method. In the first embodiment relating to the first embodiment, as compared with the conventional one. Thus, it can be seen that the number of defects per wafer is significantly reduced. The value of the number of defects depends on the size of the wafer, the developing solution, and the like.

Next, a resist developing method according to a second embodiment of the present invention will be described with reference to the drawings. Figure 4
FIG. 5 is a flow chart showing steps of the photoresist developing method of the present invention, and FIGS. 5A to 5G are schematic views of process steps showing the resist developing method according to the embodiment of the present invention.

In FIG. 4, the first step is a first developing liquid drop step 31, and as shown in FIG. 5A, the resist 2 is formed on the surface of the wafer 1 in the form of a film. The developer 4 is discharged from the developer discharge nozzle 3. At this time, the wafer 1 is attracted by the spin chuck 5 and is rotating. As a result, the developer 4 supplied on the resist 2
Are spread in the peripheral direction from the center of the wafer 1.

Next, in FIG. 4, the second step is the first step.
5 is a developing step 32, in which the rotation of the wafer 1 is stopped and the developer 4 spread over the entire surface of the wafer 1 as shown in FIG.
Is held in a paddle state on the resist 2 by surface tension. As a result, the development reaction of the resist 2 with the developer 4 proceeds. At this time, the time during which the developing solution 4 is held in the paddle state requires the time for the developing solution 4 to reach the wafer 1 under the resist 2 (development end point), that is, the developing time for enabling the resist pattern formation. Become. This is a time period during which most of the resist 2 in the exposed portion that dissolves in the developer 4 is dissolved. The paddle time at this time is
It depends on the type of resist.

Next, in FIG. 4, the third step is a developing solution shaking-off step 33, in which the wafer 1 is rotated to shake off the developing solution 4 as shown in FIG. 5C. Since the rinse liquid is not dropped after the first developing step 32 as in the conventional technique, it is possible to suppress the generation of insolubilized particles of the resist 2 which are deposited by mixing the rinse liquid and the developer. At the time of the developer shaking-off step 33, the resist 2 remaining after development is not dried, and the next step is continuously performed.

Next, in FIG. 4, the fourth step is the second step.
As shown in FIG. 5D, a new developer 8 is discharged from the developer discharge nozzle 3 as shown in FIG. 5D. At this time, the wafer 1 is spin chuck 5
It is adsorbed by and is rotating. As a result, the developing solution 4 supplied onto the resist 2 is spread from the central portion of the wafer 1 in the peripheral direction. The developer 4 and the developer 8 may be the same.

Next, in FIG. 4, the fifth step is the second step.
The developing step 35 of FIG.
Similarly to (b), the rotation of the wafer 1 is stopped, and the developing solution 4 spread over the entire surface of the wafer 1 is held on the resist 2 formed in a film shape on the surface of the wafer 1 as a new developing solution 8. As a result, the development reaction of the resist 2 with the new developer 8 proceeds.

Next, referring to FIG. 4, the sixth step is a rinse step 36, and the seventh step is a rinse liquid shake-off step 3
7, the rinse liquid 7 is discharged from the rinse liquid discharge nozzle 6 onto the wafer 1 while the wafer 1 is rotated by the spin chuck 5 as shown in FIG. By discharging the rinse liquid 7 that has been discharged with the new developing liquid 8,
The wafer 1 is cleaned. Here, pure water that is deionized water is used as the rinse liquid. In the developing solution 8, the dissolved resist 2 is significantly reduced, and it is possible to suppress the generation of insolubilized particles of the resist 2 which are deposited by mixing the rinse solution 7 and the developing solution 8.

Finally, in FIG. 4, the eighth step is a drying step 38, which is performed by rotating the wafer 1 and shaking off the rinse liquid 7 as shown in FIG.
The resist 2 patterned on the surface of the wafer 1 is spin dried.

In the resist developing method according to the first embodiment of the present invention, after the developer shaking off step 23,
Even if the rinse step 24 is performed, the insoluble matter of the resist remains. Therefore, in order to further improve this, in the second embodiment of the present invention, the developing step is performed again after the developer shaking off step 33. The remaining resist was further dissolved and washed and removed in the rinse step 34.

As shown in FIG. 3, in the second embodiment relating to the second embodiment, it can be seen that the number of defects per wafer is significantly reduced as compared with the conventional one. Also,
It can be seen from the first embodiment that the number of defects is reduced.

In the resist developing method according to the third embodiment of the present invention, the developing liquid drop step 3 in FIG.
4 to rinsing liquid shaking-off step 37 continuously, as shown in FIG.
In FIG. 5, the steps shown in FIGS. 5D to 5F are repeated at least twice.

When the developer 8 is dropped, the resist 2 in the exposed area
Is dissolved in the developing solution and the development reaction proceeds. After that, in the conventional method, the developing solution 4 on the surface of the wafer 1 is removed by the rinsing solution 7, but at this time, the rinsing solution 7 is dropped into the developing solution, so that the concentration of the developing solution decreases and the developing solution 4 is dissolved. The resist component that had been deposited was deposited and adhered to the wafer surface.
Therefore, in the embodiment of the present invention, the developing process is divided into at least three times, and the first developing solution 4 is removed by rotating the wafer 1 without using the rinse solution 7. This is because the resist 2 is dissolved in the developing solution 4 during the paddle developing process, and the dissolved solution of the dissolved resist is precipitated when the subsequent rinsing process is performed as in the conventional case, so that the first developing process is performed. Generation of particles can be prevented by omitting the rinse step after the droplet dropping step 31.

As shown in FIG. 3, in the present invention relating to the third embodiment, the steps from the developing liquid drop step 34 to the rinse liquid shaking off step 37 are performed twice, and the third embodiment (1) It can be seen that, in Embodiment 3 (2) in which the number of defects is three, the number of defects per wafer is significantly reduced as compared with the related art. In addition, Embodiment 3 (1),
From (2), it can be seen that the number of defects decreases and the number of defects decreases as the number of repetitions increases. That is, by repeating the developing process, the insoluble material of the resist generated during the rinsing process is redissolved and washed away to remove the particles.

FIG. 6 shows the developing step 22 or the developing step 32.
FIG. 4 is a characteristic diagram showing the relationship between the paddle time and the number of pattern defects that occur, and the Kr of the annealing type used this time.
For F resist, paddle time is 3 seconds, 5 seconds,
It can be seen that the number of defects decreases as the time increases to 10 seconds. It can be seen that it is optimal for 5 seconds or more.

As described above, according to the present embodiment, the developer containing the resist component is removed by the developing reaction without dropping the rinse liquid, so that the resist component is deposited when the wafer is washed with the rinse liquid. Can be reduced.

Although some embodiments of the present invention have been described in detail, the technical scope of the present invention is not limited at all. Although the present invention has been described with respect to the method of developing a positive resist, it goes without saying that the same method can be applied to the case of using a negative resist. Furthermore, resists using various types of solvents, sensitizers and additives, and chemically amplified resists can be used in the present invention. Further, the present invention can be used when the Cr area of the pattern mask used is small or large.

[0036]

As described above, according to the present invention, the developing solution containing the dissolved resist is removed from the wafer by performing the developing process of the resist coated on the wafer surface and then shaking off the developing solution. In the rinsing step of washing away the developing solution, it is possible to suppress precipitation of the resist component caused by mixing the rinsing solution and the developing solution, and it is possible to greatly reduce pattern defects.

After the developing step and the developing solution shaking off step,
By performing the second developing step before the rinsing step, the remaining resist is dissolved, and then the rinsing liquid is used for cleaning. Therefore, precipitation of resist components can be further suppressed and pattern defects can be reduced.

[Brief description of drawings]

FIG. 1 is a flowchart showing steps of a developing method according to a first embodiment of the present invention.

FIG. 2 is a schematic view of process steps showing a developing method according to the first embodiment of the present invention.

FIG. 3 is a characteristic diagram comparing the number of pattern defects generated in the developing method according to the embodiment of the present invention with the conventional developing method.

FIG. 4 is a flowchart showing steps of a developing method according to a second embodiment of the present invention.

FIG. 5 is a schematic view of process steps showing a developing method according to a second embodiment of the present invention.

FIG. 6 is a characteristic diagram showing the relationship between the paddle time and the number of defects that occur in the embodiment of the present invention.

FIG. 7 is a flowchart showing steps of a conventional developing method.

FIG. 8 is a schematic view of process steps showing a conventional developing method.

[Explanation of symbols]

1 wafer 2 resist 3 Developer discharge nozzle 4 developer 5 Spin chuck 6 Rinse liquid discharge nozzle 7 rinse liquid 8 developer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hirofumi Fukumoto             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Fumio Iwamoto             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 2H096 AA25 GA17 GA29 GA30                 5F046 LA03 LA08 LA14

Claims (6)

[Claims] 1. A step of supplying a developing solution onto the semiconductor wafer while rotating a semiconductor wafer whose surface is coated with a resist, and a step of stopping the rotation of the semiconductor wafer and applying the developing solution onto the surface of the semiconductor wafer. A step of advancing a developing reaction of the resist, and a step of rotating the semiconductor wafer to remove the developing solution and the resist dissolved in the developing solution before a rinsing step of washing out the developing solution. And developing method. 2. A first developing liquid dropping step of supplying a developing solution onto the semiconductor wafer while rotating a semiconductor wafer having a surface coated with a resist, and stopping the supply of the developing solution to stop the surface of the semiconductor wafer. In a first developing step of advancing a resist developing reaction by the developing solution; a step of rotating the semiconductor wafer to remove the developing solution and the resist dissolved in the developing solution; A second developing liquid drop step of supplying the developing solution to the surface of the semiconductor wafer while rotating, and stopping the supply of the developing solution to advance a resist developing reaction by the developing solution on the surface of the semiconductor wafer. A second developing step of dissolving the resist which could not be completely dissolved,
And a step of rinsing the developing solution and the dissolved resist using a rinse solution. 3. A paddle is formed in the first developing step, and a developing time is equal to or longer than a time required for the developing solution to dissolve the resist and reach the semiconductor wafer. The developing method described. 4. The developing method according to claim 2, wherein the resist remaining after development is not dried after the step of removing the resist and before the step of lowering the second developing droplet. 5. The combination of the second developing liquid dropping step, the second developing step and the step of washing away the dissolved resist with the developing solution using a rinse solution is performed at least twice or more. 2. The developing method described in 2. 6. The developing method according to claim 2, wherein a paddle is formed in the second developing step, and a developing time is at least a time for forming a resist pattern.