KR102009850B1

KR102009850B1 - Thinner composition for improving coating and removing performance of resist

Info

Publication number: KR102009850B1
Application number: KR1020130034773A
Authority: KR
Inventors: 김정환; 최철민; 김상태; 이경호
Original assignee: 동우 화인켐 주식회사
Priority date: 2013-03-29
Filing date: 2013-03-29
Publication date: 2019-08-13
Also published as: KR20140119949A

Abstract

The present invention includes methoxy butyl acetate and ketone, so that even if a small amount of photoresist or SOH can be applied evenly on the front surface of the substrate, thereby reducing the amount of photoresist used to improve the process cost and productivity The present invention relates to a thinner composition excellent in removing unnecessary photoresist after photoresist application.

Description

Thinner composition for improving and removing resist coating property {THINNER COMPOSITION FOR IMPROVING COATING AND REMOVING PERFORMANCE OF RESIST}

The present invention relates to a thinner composition for improving and removing resist coating property.

Like a semiconductor integrated circuit, a fine circuit pattern is uniformly coated with a photoresist containing a photosensitive compound and a solvent by a rotation coating method on a conductive metal film or an oxide film formed on a substrate, and then subjected to exposure, development, etching and peeling processes. It is manufactured through a method for implementing a desired microcircuit pattern. At this time, since the exposure process, which is a subsequent process, is implemented by exposing a desired pattern to the coating film using light having a short wavelength in the ultraviolet region, it is very sensitive to external and internal contamination. Therefore, undesired photoresist residues and other contaminants applied to the edges or backsides of the substrate in the application process may be fatal sources of contamination in the subsequent exposure process and must be removed. In order to remove such contaminants, thinner compositions have been used in an EBR (edge bead removing) process.

Conventionally, single solvents such as ethyl cellosolve acetate (ECA), methylmethoxy propionate (MMP) and ethyl lactate (EL) are widely used as thinner compositions for removing photoresist. Although used, ethyl cellosolve acetate has been problematic in its use due to its harmfulness to the human body, and methyl methoxy propionate and ethyl lactate due to economic and performance limitations.

In order to solve this problem, a conventional method of mixing a single solvent has been developed. As a thinner composition in the form of such a mixture, a mixture of propylene glycol alkyl ether propionate and methyl ethyl ketone, or propylene glycol alkyl ether pro A mixture of cypionate and butyl acetate (Japanese Patent Laid-Open No. 7-160008); Mixtures of ethyl lactate and propylene glycol alkyl ethers (US Pat. No. 4,886,728) and the like are known.

On the other hand, in recent years, as the degree of integration of semiconductors has increased, photoresists using short-wavelength KrF and ArF (including ArF immersion) light sources have been applied. There has been a continuous need to reduce the amount of photoresist used.

Due to this demand, the surface of the substrate is first treated with a treatment composition before the photoresist is applied so that the photoresist can be evenly applied to the entire surface of the substrate even with a small amount of photoresist. ) Has been applied. As the size of the substrate (wafer) increases with the increase in the degree of integration, the importance of the RRC process is further increased. Therefore, it is required to develop a treatment composition having a high RRC efficiency while sufficiently proceeding with the existing EBR process.

Currently, the photoresist residue removal process and the photoresist pretreatment process are separate processes, and the thinner composition and the photoresist pretreatment composition used in the residue removal process are used in separate compositions.

Patent Document 1: Japanese Patent Application Laid-Open No. 7-160008 Patent Document 2: US Patent No. 4,886,728

It is an object of the present invention to provide a thinner composition that can be used simultaneously in an RBR process as well as an EBR process.

In addition, the present invention is to provide a thinner composition that can not only drastically reduce the amount of photoresist or spin on hardmask (SOH) used to implement the pattern, but also to achieve uniform application of the photoresist. It is done.

In addition, another object of the present invention is to provide a thinner composition capable of effectively removing unnecessary photoresist applied to an edge portion or a rear surface portion of a substrate.

1. A thinner composition for improving and removing resist coating property comprising methoxy butyl acetate and ketone having 2 to 10 carbon atoms.

2. In the above 1, the ketone is propylene acetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl pentyl ketone, ethyl propyl ketone, ethyl butyl ketone, ethyl pentyl ketone, cyclopentanone, cyclohexanone and cyclo Thinner composition which is at least 1 sort (s) chosen from the group which consists of heptanone.

3. In the above 1, the mixed weight ratio of the methoxy butyl acetate and the ketone is 30:70 to 70:30 thinner composition.

4. A substrate treatment method in which the substrate is treated with the thinner composition of any one of 1 to 4 above before applying photoresist or SOH to the substrate.

5. Substrate treatment method for treating the substrate with the thinner composition of any one of 1 to 4 above before the exposure process after the photoresist or SOH applied to the substrate.

The thinner composition of the present invention can be evenly applied to the entire surface of the substrate even using a small amount of photoresist or SOH, it is possible to reduce the amount of photoresist used to improve the process cost and productivity.

The thinner composition of the present invention can be sprayed on the edge portion and the rear portion of the substrate to quickly and effectively remove unnecessary photoresist and SOH.

The thinner composition of the present invention has excellent solubility in various photoresist films, SOH layers, lower antireflection films (BARC) and underlayers.

The thinner composition of the present invention has excellent solubility in the main components of the photoresist and the antireflection film having a high polarity structure, and thus, after the EBR process, the lower wafer cleaning process, and the pretreatment process on the wafer top before the photoresist coating, No contamination of the cup holder or clogging of the outlet is caused.

FIG. 1 shows a case in which a thinner composition 0.5cc is coated on an 8-inch wafer and a photoresist is applied, whereby the photoresist is applied to a wafer of 99 to 100% or more.
FIG. 2 shows a case where 0.5 cc of thinner composition is applied on an 8 inch wafer and a photoresist is applied, where the photoresist is applied on the wafer at less than 95%.
3 shows the evaluation point of the coating uniformity according to the type of photoresist applied on the wafer.

Hereinafter, the present invention will be described in detail.

The thinner composition of the present invention comprises methoxy butyl acetate and ketone.

The methoxy butyl acetate used in the present invention is particularly excellent in EBR process characteristics and RRC effects when used as a thinner composition when compared to other alkoxy alkyl acetates having a similar structure.

The methoxy butyl acetate is not particularly limited in the content to the extent that it can function, but may be included in 30 to 70% by weight, preferably 40 to 60% by weight relative to the total weight of the mixture with the ketone. have. If the content of the alkoxy alkyl acetate is 30% by weight or more and 70% by weight or less of the total weight of the mixture with the ketone, the composition may have an appropriate volatilization and thus tailing in an unnecessary edge removal process (EBR) of the edge portion. Without this, the removal process can be performed effectively, the coating uniformity can be maintained well, and the reducing resist consumption (RRC) effect of applying the wafer with a small amount of photoresist and SOH is maximized.

If the ketone is a ketone having 1 to 10 carbon atoms, the kind thereof is not particularly limited, and for example, propylene acetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl pentyl ketone, ethyl propyl ketone, ethyl butyl ketone, ethyl pentyl ketone And cyclopentanone, cyclohexanone, cycloheptanone and the like. These can be used individually or in mixture of 2 or more types.

Ketone is not particularly limited in the content to the extent that it can function, but may be included in 30 to 70% by weight, preferably 40 to 60% by weight relative to the total weight of the mixture with methoxy butyl acetate. have. When the ketone content is included in an amount of 30 wt% or more and 70 wt% or less in the total weight of the mixture with methoxy butyl acetate, the composition has an appropriate volatility and surface tension and shows excellent solubility to maximize the EBR process characteristics and the RRC effect. .

Optionally, the thinner composition of the present invention may further include a solvent used in the art without departing from the object of the present invention. For example, it may include propylene glycol alkyl ether propionate, alkyl alkoxy propionate, alkyl lactate, propylene glycol alkyl ether, propylene glycol alkyl ether acetate, and the like, and preferably propylene glycol alkyl in terms of maximizing the RRC effect. Ether or propylene glycol alkyl ether acetates.

The propylene glycol alkyl ether is not particularly limited as long as it has an alkyl group having 1 to 10 carbon atoms, and examples thereof include propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, and propylene glycol butyl ether. These can be used individually or in mixture of 2 or more types.

The propylene glycol alkyl ether acetate is not particularly limited as long as it has an alkyl group having 1 to 10 carbon atoms. For example, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, propylene glycol butyl ether acetate, and the like. Can be mentioned. These can be used individually or in mixture of 2 or more types.

Optionally, the thinner composition of the present invention may further add conventional additives in addition to the aforementioned components, and the additives include surfactant. pH adjusters and the like can be used.

In addition, the additive is not limited thereto, and in order to further improve the effects of the present invention, various other additives known in the art may be selected and added.

The thinner composition of the present invention comprising the above components is first surface-treated on the substrate before the photoresist or SOH is applied to the substrate during the semiconductor device manufacturing process, and evenly applied to the entire surface of the substrate even when a small amount of photoresist or SOH is used. By reducing the amount of photoresist or SOH used, the process cost and productivity can be improved. Furthermore, after the photoresist or SOH is applied to a substrate, the substrate is treated with the thinner composition of the present invention before the exposure process. In addition, unnecessary photoresist or SOH applied to the edge portion or the back side of the substrate can be removed quickly and effectively.

That is, when the thinner composition of the present invention is used, an RRC process and an EBR process may be efficiently performed when manufacturing a semiconductor device.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but these examples are merely illustrative of the present invention and are not intended to limit the scope of the appended claims, which are within the scope and spirit of the present invention. It is apparent to those skilled in the art that various changes and modifications can be made to the present invention, and such modifications and changes belong to the appended claims.

Example 1-7 and Comparative example 1-5

The components shown in Table 1 below were added to the mixing tank equipped with a stirrer at a corresponding composition ratio, and then stirred at a speed of 500 rpm for 1 hour at room temperature to prepare a thinner composition.

division Alkoxy Alkyl Acetate
(weight%) Ketone
(weight%) Propylene Glycol Alkyl Ether Acetate
(weight%) Alkyl esters
(weight%) ingredient Parts by weight ingredient Parts by weight ingredient Parts by weight ingredient Parts by weight Example 1 A-1 30 B-1 70 - - - - Example 2 A-1 40 B-1 60 - - - - Example 3 A-1 50 B-1 50 - - - - Example 4 A-1 60 B-1 40 - - - - Example 5 A-1 70 B-1 30 - - - - Example 6 A-1 50 B-2 50 - - - - Example 7 A-1 60 B-3 40 - - - - Comparative Example 1 A-1 100 - - - - - - Comparative Example 2 - - B-1 100 - - - - Comparative Example 3 - - B-3 2 C-1 88 D-1 10 Comparative Example 4 A-2 50 B-1 50 - - - - Comparative Example 5 A-2 50 B-3 50 - - - - A-1: methoxy butyl acetate, A-2: methoxy methyl acetate,
B-1: methyl pentyl ketone, B-2: methyl butyl ketone
B-3: cycloheptanone
C-1: propylene glycol monomethyl ether acetate,
D-1: ethyl lactate

Test Example

One. RRC ( reducing resist consumption Performance evaluation

The thinner compositions of Examples 1-7 and Comparative Examples 1-5 were used to evaluate RRC performance for the photoresist, SOH and BARC of Table 2 below.

0.5cc of each thinner composition was applied to an 8-inch silicon oxide substrate according to the steps shown in Table 3, PR (Photoresist) 1 to 4 and spin on hardmask (SOH) were 1.0 cc, and Bottom of Anti Reflection Coating (BARC) After application of 0.4 cc each, application distribution and consumption of photoresist and SOH according to the substrate treatment agent were measured. In the case of BARC, the coating distribution and consumption of BARC according to the substrate treatment agent were measured using the respective thinner composition without heat treatment.

The results are shown in Table 4 below.

◎: 99 to 100% of photoresist is applied on wafer

(Circle): When photoresist is apply | coated 97-98% on a wafer

(Triangle | delta): When 95-96% of photoresists are apply | coated on a wafer

X: less than 95% photoresist applied onto wafer

division PR (Photoresist) Type PR 1 PR for i-line PR 2 PR for KrF PR 3 PR for ArF PR 4 PR for ArF-immersion SOH Resin for SOH BARC BARC for ArF

step Time (sec) Speed (rpm) Accelerator (rpm / sec) Dispense (cc) One 2.5 0 10,000 0.5 (substrate treatment agent) 2 1.5 900 10,000 0 3 9.5 1500 10,000 0 4 5.0 600 10,000 0.4-1 (PR) 5 5.0 1500 10,000 0 6 10.0 1000 10,000 0

Referring to the application conditions with reference to Table 3, 0.5cc of the thinner composition was sprayed on the substrate for 2.5 seconds as a first step. In the second step, the substrate was rotated so that the thinner composition spreads on the wafer for 1.5 seconds. In the third step, the substrate was rotated for 9.5 seconds. In the fourth step, the photoresist, SOH, and BARC sprayed on the substrate were applied to the entire surface by relatively rotating the substrate while spraying the photoresist, SOH, and BARC. The substrate was rotated for 5 seconds in the fifth step and for 10 seconds in the sixth step.

division PR 1
(1.0cc) PR 2
(1.0cc) PR 3
(1.0cc) PR 4
(1.0cc) SOH
(1.0cc) BARC
(0.4cc) Example 1 ◎ ○ ◎ ◎ ◎ ◎ Example 2 ◎ ○ ◎ ◎ ◎ ◎ Example 3 ◎ ○ ◎ ◎ ◎ ◎ Example 4 ◎ ○ ◎ ◎ ◎ ◎ Example 5 ◎ ○ ◎ ◎ ◎ ◎ Example 6 ◎ ○ ◎ ◎ ◎ ◎ Example 7 ◎ ○ ◎ ◎ ◎ ◎ Comparative Example 1 X X X X X X Comparative Example 2 X X X X X X Comparative Example 3 △ X △ X X X Comparative Example 4 X △ △ △ X X Comparative Example 5 X △ △ △ X X

Referring to Table 4, the thinner composition of Examples 1 to 7 according to the present invention was confirmed that the photoresist, SOH and BARC is applied to more than 97% or 99% of all the photoresist film exhibiting excellent RRC performance. In addition, even in the case of changing the rotational speed (rpm) condition of the RRC was maintained equally good form. This means that the thinner composition according to the present invention is not only effective under specific conditions, but also exhibits the same performance under various conditions, and is more stable than conventional compositions with respect to changes in process conditions.

On the other hand, the thinner composition of Comparative Examples 1 to 5 was confirmed that the coating rate of the photoresist, SOH and BARC is less than 95% or only 95-96%, so that the coating property is poor.

2. for the photosensitive resin composition Thinner Unnecessary photoresist removal experiment of composition

After applying the same photoresist, SOH and BARC as in Test Example 1 to an 8 inch silicon oxide substrate, the thinner compositions of Examples 1 to 7 and Comparative Examples 1 to 5 were subjected to the conditions described in Table 5 below. As a result, an experiment for removing unnecessary photoresist at the edge portion (Edge Bead Removing Experiment: hereinafter referred to as EBR experiment) was performed.

Each of the thinner compositions of Examples 1 to 7 and Comparative Examples 1 to 5 was supplied from a pressure vessel equipped with a pressure gauge, and the pressure was 1 kgf, and the flow rate of the thinner composition from the EBR nozzle was 10 to 30 cc / min. . In addition, the removal performance of the unnecessary photoresist film was evaluated using an optical microscope and a scanning electron microscope, and the results are shown in Table 6 below.

◎: EBR line uniformity for the photosensitive film is constant

○: Good linear state with EBR line uniformity of 75% or more for the photosensitive film

(Triangle | delta): The state of the edge part was distorted by the dissolution action of the substrate processing agent.

X: Tailing phenomenon occurs at the edge of the film

division Rotation speed (rpm) Sec Distribution conditions 300-2000 7 Spin coating 2000 15 EBR condition 1500 20 Dry condition 1300 6

division PR 1 PR 2 PR 3 PR 4 SOH BARC Example 1 ◎ ◎ ○ ○ ◎ ○ Example 2 ◎ ◎ ◎ ◎ ◎ ◎ Example 3 ◎ ◎ ◎ ◎ ◎ ◎ Example 4 ◎ ◎ ○ ◎ ◎ ○ Example 5 ◎ ◎ ○ ○ ◎ ○ Example 6 ◎ ◎ ◎ ◎ ◎ ○ Example 7 ◎ ◎ ◎ ◎ ◎ ○ Comparative Example 1 X X X X X X Comparative Example 2 X X X X X X Comparative Example 3 △ X △ △ X △ Comparative Example 4 △ X △ △ △ △ Comparative Example 5 △ X △ △ △ △

Referring to Table 6, the thinner compositions of Examples 1 to 7 according to the present invention exhibited a uniform linear state with uniformity or 75% or more of EBR lines for all photoresist films, such that various films such as photoresist, SOH, BARC, etc. It can be confirmed that has an excellent EBR performance for.

In addition, even when the rotational speed (rpm) condition of the EBR was changed to 2000, an excellent form was maintained. This means that the thinner composition according to the present invention is not only effective under specific conditions, but also exhibits the same performance under various conditions, and is more stable than conventional compositions with respect to changes in process conditions.

On the other hand, the thinner compositions of Comparative Examples 1 to 5 were found to have a tailing phenomenon in the film of the edge portion or dissolve in the substrate treating agent, resulting in a distorted shape, thereby degrading the removal performance of the unnecessary photosensitive film.

3. Evaluation of Coating Uniformity

The coating uniformity for the photoresist, SOH and BARC of Table 2 was tested using the thinner compositions of Examples 1-7 and Comparative Examples 1-5. After applying photoresist, SOH, and BARC on 8-inch silicon oxide substrate, follow the steps as shown in Table 7 and 16 in 1-inch and 2-inch distances from the center of the wafer and the center of the wafer. The location (see FIG. 3) was measured to confirm that the photoresist was uniformly applied, and the results are shown in Table 8 below.

(Double-circle): When the standard deviation of film thickness is 0 to 1%

○: when the standard deviation of the film thickness is 1-2%

(Triangle | delta): When the standard deviation of a film thickness is 2-3%

X: Standard deviation of the film thickness is more than 3%

step Time (sec) Speed (rpm) Accelerator (rpm / sec) Dispense (cc) One 5 0 10,000 2.0 (substrate treatment agent) 2 5 700 10,000 0 3 3 2,000 10,000 0 4 20 2,000 10,000 0.30 (PR) 5 5 700 10,000 0 6 5 0 10,000 0

division PR 1 PR 2 PR 3 PR 4 SOH BARC Example 1 ○ ○ ○ ○ ○ ○ Example 2 ○ ◎ ◎ ◎ ◎ ◎ Example 3 ○ ◎ ◎ ◎ ◎ ◎ Example 4 ◎ ◎ ◎ ◎ ◎ ◎ Example 5 ◎ ◎ ◎ ◎ ◎ ◎ Example 6 ○ ◎ ◎ ◎ ◎ ◎ Example 7 ◎ ◎ ◎ ◎ ◎ ◎ Comparative Example 1 X X X X X X Comparative Example 2 X X X X X X Comparative Example 3 △ X △ X X X Comparative Example 4 △ X △ △ △ △ Comparative Example 5 △ X △ △ △ △

Referring to Table 8, the thinner composition of Examples 1 to 7 was confirmed that the standard deviation of the film thickness is less than 1% or only 1 to 2% excellent in the uniformity of the coating.

On the other hand, in the thinner compositions of Comparative Examples 1 to 5, the standard deviation of the film thickness was 2 to 3% or more than 3%.

4. Rework Performance evaluation

The rework performance for the photoresist, SOH and BARC of Table 2 was tested using the thinner compositions of Examples 1-7 and Comparative Examples 1-5. The photoresist and SOH were apply | coated to an 8-inch silicon-oxide board | substrate, and the rework process was performed using the thinner composition on the wafer which the soft baking process was completed, according to the steps as shown in Table 9 below. In the case of BARC, the rework process was performed using each thinner composition without heat treatment after application.

The reworked silicon oxide substrate was evaluated using a surface scan equipment (Model name: WM-1500) manufactured by TOPCON, and the results were shown in Table 10 below.

◎: When the number of reworked silicon oxide surface particles is less than 1000

○: when the number of reworked silicon oxide surface particles is 1000 or more and less than 2000

(Triangle | delta): When the number of reworked silicon oxide surface particles is 2000 or more and less than 3000

X: When the number of reworked silicon oxide surface particles is 3000 or more

step Time (sec) Speed (rpm) Accelerator (rpm / sec) Dispense (cc) One 2 0 10,000 0 2 2 1000 10,000 0 3 4 1000 10,000 2.0 (substrate treatment agent) 4 9.5 4000 10,000 0 5 0 0 10,000 0

division PR 1 PR 2 PR 3 PR 4 SOH BARC Example 1 ○ ○ ○ ○ ◎ ○ Example 2 ◎ ◎ ○ ○ ◎ ◎ Example 3 ◎ ◎ ◎ ◎ ◎ ◎ Example 4 ◎ ◎ ◎ ◎ ◎ ◎ Example 5 ◎ ◎ ○ ○ ◎ ○ Example 6 ◎ ◎ ◎ ◎ ◎ ○ Example 7 ◎ ◎ ◎ ◎ ◎ ○ Comparative Example 1 X X X X X X Comparative Example 2 X X X X X X Comparative Example 3 △ X △ △ X △ Comparative Example 4 △ X △ △ △ △ Comparative Example 5 △ X △ △ △ △

Referring to Table 10, the thinner composition of Examples 1 to 7 was confirmed that the rework performance is excellent because the number of the surface particles of the reworked silicon oxide is less than 1000 or only 1000 ~ 2000.

On the other hand, in the thinner compositions of Comparative Examples 1 to 5, the number of reworked silicon oxide surface particles exceeded 2000 to 3000 or more than 3000, indicating that the rework performance was deteriorated.

Claims

Methoxy butyl acetate and ketones having 2 to 10 carbon atoms,
The mixed weight ratio of the methoxy butyl acetate and the ketone is 40:60 to 60:40,
A thinner composition for improving and removing resist coating property, which is used in a photoresist reduction (RRC) process and an edge bead removal (EBR) process.

The method of claim 1, wherein the ketone is propylene acetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl pentyl ketone, ethyl propyl ketone, ethyl butyl ketone, ethyl pentyl ketone, cyclopentanone, cyclohexanone and cycloheptanone Thinner composition which is at least one selected from the group consisting of.

delete

A substrate treating method wherein the substrate is treated with the thinner composition of claim 1 before applying photoresist or SOH to the substrate.

The substrate processing method of processing the said board | substrate with the thinner composition of any one of Claims 1-2 before an exposure process after apply | coating a photoresist or SOH to a board | substrate.