KR20130130437A - Thinner composition to reduce photoresist consumption - Google Patents

Abstract

The present invention relates to a thinner composition comprising alkoxy alkyl propionate, propylene glycol alkyl ether acetate and alkyl acetate. The thinner composition decreases the consumption of photoresist represents by increasing the coating performance of the photoresist before applying the photoresist, thereby exhibiting excellent performance in a process for applying the thinner composition first, showing excellent solubility and EBR properties about various photoresists and bottom anti-reflective coating (BARC) and having excellent properties when being used in a salvage process for a wafer in which photoresist is coated.

Description

Thinner composition to reduce photoresist consumption

The present invention relates to a thinner composition that can reduce the amount of photoresist used.

More specifically, the present invention relates to a thinner composition that can reduce the amount of photoresist while at the same time excellent in the process of pre-processing the wafer surface in order to improve the coating performance of the photoresist, various photoresist and lower antireflection film A thinner composition having excellent solubility and EBR properties for (BARC) and underlayer, and also having excellent properties in a rework process of a wafer using a photoresist.

The photolithography process of manufacturing a semiconductor device is a process of applying a photosensitive resin composition on a wafer, transferring a previously designed pattern, and composing an electronic circuit through an etching process appropriately according to the transferred pattern. This is one of the very important tasks.

The photolithography process includes (1) an application step of uniformly applying the photosensitive resin composition to the surface of the wafer, and (2) a soft baking step of evaporating the solvent from the coated photoresist film so that the photoresist film adheres to the surface of the wafer. (3) an exposure step of exposing the photoresist film by repeatedly and sequentially reducing and projecting the circuit pattern on the mask by using a light source such as ultraviolet ray, and (4) an exposure step of exposing the mask pattern onto the photoresist film, and (4) exposure to light sources. Development process for selectively removing parts having different physical properties such as difference in solubility using developer, (5) hard baking to more closely adhere the photoresist film remaining on the wafer to the wafer after development Process, (6) an etching process for etching a certain portion according to the developed photoresist pattern, and (7) an unnecessary feeling after the process. It goes to a separation step such as removing a film.

In the photolithography process, the photocoating film is supplied onto the wafer and the substrate is rotated to spread the surface evenly by centrifugal force, so that the photoresist film is gathered at the edge portion and the rear surface of the substrate due to the centrifugal force to form a small spherical material. The spherical material may be peeled off during transfer of the substrate after the baking process to cause particles in the apparatus, or may cause defocus during exposure. This unnecessary photosensitive material causes equipment contamination and lowers the yield in the manufacturing process of the semiconductor device. Therefore, spray nozzles are installed above and below the edge portion and the rear portion of the substrate, and the organic solvent component is formed at the edge portion and the rear portion through the nozzle. It is removed by spraying a thinner composition consisting of.

Factors that determine the performance of the thinner composition include dissolution rate and volatility. The dissolution rate of the thinner composition is very important because it determines how quickly and effectively the photosensitive resin can be dissolved and removed. Specifically, in the rinse of the edge portion, it may have a smooth processing cross section only if it has an appropriate dissolution rate, and if the dissolution rate is too high, a photoresist attack may appear in the rinse of the photoresist applied to the substrate. On the contrary, when the dissolution rate is too low, a partially dissolved photosensitive film tail flow phenomenon called tailing may appear in the rinse of the photosensitive film applied to the substrate. In particular, due to the large diameter of the substrate due to the high integration and high density of the semiconductor integrated circuit in recent years, in the rinsing process using the abandonment of the rotation speed it is inevitable to reduce the rotation speed (rpm). In such a rinse process, when the substrate does not have an appropriate dissolution rate in the rocking phenomenon of the substrate due to low rotation and the contact speed of the sprayed thinner composition, a bounding phenomenon occurs and the use of unnecessary thinner composition increases. In the low rotation rinse process due to the large diameter of such a substrate, a stronger dissolution rate of thinner is required than the conventional high rotation rinse process.

In addition, the thinner composition is required to easily volatilize and remain on the surface of the substrate after removing the photosensitive resin. When the volatility is too low and the thinner composition does not volatilize, the remaining thinner itself may act as a contaminant in various processes, in particular, subsequent etching, and thus may act as a problem of lowering the yield of the semiconductor device. On the contrary, if the volatility is too high, the substrate may be rapidly cooled and the thickness variation of the applied photoresist may be increased, and the volatilization may be easily volatilized to the atmosphere during use, thereby causing deterioration of cleanliness.

Currently, i-line photoresist, KrF, ArF, EUV, KrF antireflection film, ArF antireflection film, etc., which are used as photoresist in semiconductor lithography process, all have different main components. Therefore, it is necessary to control the composition content of the organic solvent in order to improve solubility and coatability of all of them.

Korean Patent Registration No. 10-0951365 discloses a composition for use in a semiconductor device and a liquid crystal display device manufacturing process comprising an alkylene glycol mono alkyl ether propionate, alkyl lactate and gamma butyrolactone. However, the composition has a high content of alkoxy alkyl propionate, which lowers volatility, induces tailing phenomenon on the photoresist removal interface, and may act as an interfering particle in a subsequent process, thereby lowering the productivity of the manufacturing process. It causes the price of thinner.

Korean Patent Laid-Open Publication No. 10-2011-0021189 discloses a thinner composition including an organic solvent capable of hydrogen bonding, glycols, esters, and the like, which can reduce the amount of photoresist coating and It is possible to achieve uniform coating and to effectively remove unnecessary photoresist applied to the edge portion or the rear surface of the substrate. However, the viscosity of the thinner increases due to hydrogen bonding and the volatility decreases, so that the thinner cannot remain volatilized and thus induces a tailing phenomenon on the photoresist removal interface, and also acts as an interfering particle in a subsequent process, thereby lowering the productivity of the manufacturing process. Can be generated.

Therefore, it has excellent solubility in various photoresist films, BARCs and underlayers, and has an appropriate volatilization so as to show excellent coating performance in applying photoresist, thereby reducing the amount of photoresist used. A thinner composition that can be used is required.

KR 10-0951365 B KR 10-2011-0021189 A

An object of the present invention is to provide a thinner composition that can reduce the amount of photoresist while having excellent properties even in the process of pre-treating the wafer surface in order to improve the coating performance of the photoresist.

In addition, the present invention provides a thinner composition having excellent solubility and EBR characteristics for various photoresists, anti-reflective films (BARCs) and underlayers, and excellent properties in the rework process of wafers using photoresists. It is to.

In order to achieve the above object, the present invention provides a thinner composition comprising alkoxy alkyl propionate, propylene glycol alkyl ether acetate and alkyl acetate.

Since the thinner composition of the present invention improves the coating performance of the photoresist before applying the photoresist to reduce the amount of photoresist used, the thinner composition shows excellent performance even in the process of first applying the thinner composition.

In addition, it has excellent solubility and EBR characteristics with respect to various photoresists such as photoresist for ArF and lower antireflection film (BARC), and shows excellent characteristics when used in the regeneration process of a photoresist coated wafer.

FIG. 1 is a photograph of the case where photoresist is 100% coated on a wafer when the photoresist is applied after the thinner 0.5cc is applied on an 8 inch wafer (?: RRC result).
FIG. 2 is a photograph of a case in which photoresist is applied on a wafer at less than 90% (X: RRC result) when a photoresist is applied after 0.5 cc of thinner is applied on an 8 inch wafer.

Hereinafter, the present invention will be described in more detail.

The thinner composition of the present invention is characterized by comprising an alkoxy alkyl propionate, propylene glycol alkyl ether acetate and alkyl acetate.

The thinner composition preferably contains 25.0 to 45.0 wt% of alkoxy alkyl propionate, 15.0 to 60.0 wt% of propylene glycol alkyl ether acetate, and 25.0 to 65.0 wt% of alkyl acetate. More preferably 30.0-40.0 wt% of alkoxy alkyl propionate, 15.0-40.0 wt% propylene glycol alkyl ether acetate and 25.0-50.0 wt% alkyl acetate.

The alkoxy alkyl propionate is methoxy methyl propionate, methoxy ethyl propionate, methoxy propyl propionate, methoxy butyl propionate, ethoxy methyl propionate, ethoxy ethyl propionate, It is 1 type chosen from the group which consists of a methoxy propyl propionate and an ethoxy butyl propionate.

When the alkoxy alkyl propionate is included in less than 30.0% by weight, the reducing resist coating (RRC) effect of applying the wafer with a small amount of photoresist is inferior, which is not preferable. Moreover, even if it exceeds 40.0 weight%, although photoresist is apply | coated uniformly, there is no big performance improvement in the effect aimed at by this invention.

The propylene glycol alkyl ether acetate is preferably an alkyl group having 1 to 10 carbon atoms, more preferably one selected from the group consisting of propylene glycol methyl ether acetate and propylene glycol ethyl ether acetate.

Propylene glycol alkyl ether acetate has an excellent solubility in photoresist and an appropriate surface tension is realized to uniformly apply the photoresist. However, when the range of propylene glycol alkyl ether acetate is included in less than 15.0% by weight, the surface tension is increased so that it does not spread evenly when the photoresist is applied and the edges may be cracked because the step of the microplate pattern on the wafer may not be overcome.

The alkyl acetate is preferably n-butyl acetate.

When the alkyl acetate is included in less than 25.0% by weight it is difficult to achieve the desired effect in the present invention, when contained in excess of 65.0% by weight is lowered the volatilization is thinner does not volatilize to induce the tailing phenomenon on the photoresist removal interface In addition, it may cause a problem of lowering productivity by acting as an interfering particle in a subsequent process.

The thinner composition may further include an additive. The additives are low molecular weight (Mw <200) hydrocarbon-based glycol ether types of ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether and diethylene glycol di 1 type selected from the group consisting of ethyl ether.

The additive is included in an amount of 10 to 1000 ppm by weight based on the total weight of the composition, and when the aforementioned range is satisfied, the EBR characteristic is improved and the surface tension is reduced to reduce defects that may occur in the process.

The thinner composition of the present invention is a wafer prior to applying the photoresist in the EBR process, the rework process, the wafer bottom surface cleaning process, the photoresist coating process in the manufacturing process of the semiconductor device or the thin film transistor liquid crystal display device It can be used in the process of pretreating the surface.

The thinner composition of the present invention can not only drastically reduce the amount of photoresist used for implementing the pattern, but also achieve uniform coating, and effectively remove unnecessary photoresist by spraying on the edge and back of the substrate. It can be used in the method of manufacturing a semiconductor device or a thin film transistor liquid crystal display device characterized in that. At this time, the injection amount of the thinner composition is preferably 5 to 50 cc / min.

After the process, the manufacturing of the semiconductor device and the thin film transistor liquid crystal display device may be manufactured by a general technique known in the art.

The thinner composition of the present invention has excellent solubility in various photoresist films, lower antireflection films (BARC), and underlayers, and can improve EBR properties, rework properties, and coating performance of photoresists. In particular, since the basic structure of the photosensitive resin constituting the photoresist for i-line, KrF, and ArF is different, it is necessary to adjust the composition content of the organic solvent to improve solubility and coatability of all of them. The thinner composition satisfies this.

In addition, the thinner composition of the present invention has excellent solubility in the main components of the photoresist and the anti-reflection film having a high polarity structure, and thus, after the EBR process, the lower wafer cleaning process, and the pretreatment process on the upper wafer before the photoresist coating is finished. It does not contaminate the cup holder of the coater or block the outlet.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the scope of the present invention is not limited thereto.

Example  1 to 7 and Comparative Example  1 ~ 7: Thinner  Preparation of the composition

The alkoxy alkyl propionate, propylene glycol alkyl ether acetate and alkyl acetate were added to the mixing tank equipped with the stirrer at the composition ratio shown in Table 1 below, and then stirred at a speed of 500 rpm for 1 hour at room temperature to prepare a thinner composition.

A (% by weight) B
(weight%) C
(weight%) D (% by weight) E (% by weight) additive
(Weight ppm) Example 1 25.0 15.0 60.0 Example 2 30.0 20.0 50.0 Example 3 35.0 20.0 45.0 Example 4 40.0 40.0 20.0 Example 5 45.0 15.0 40.0 Example 6 30.0 20.0 50.0 100 Example 7 35.0 25.0 40.0 100 Comparative Example 1 100.0 Comparative Example 2 100.0 Comparative Example 3 100.0 Comparative Example 4 35.0 65.0 Comparative Example 5 35.0 65.0 Comparative Example 6 10.0 10.0 80.0 Comparative Example 7 40.0 10.0 50.0

[week]

A: methoxy propyl propionate

B: Propylene Glycol Monomethyl Ether Acetate

C: butyl acetate

D: ethyl acetate

E: propyl acetate

Excipients: diethylene glycol methyl ethyl ether

Test Example  One: Photoresist  Depending on the type RRC ( 감 resist coating Performance evaluation

RRC performance was tested for the five photoresists of Table 2 below using the thinner compositions of Examples 1-7 and Comparative Examples 1-7. In accordance with the recipe as shown in Table 3 below, before applying the five photoresist to the 8-inch silicon oxide substrate, each of the thinner composition was applied and then the RRC process of measuring the distribution and consumption of the photoresist according to the thinner composition was performed. Even in the case of BARC, the RRC process was performed using each thinner composition without heat treatment. After applying 0.5 cc of the thinner composition on an 8-inch wafer, after applying 1.0 cc for PR1 to PR4 and 0.4 cc for BARC, the results of photoresist consumption are shown in Table 4 below.

division PR type PR1 PR for i-line PR2 PR for KrF PR3 PR for ArF PR4 PR for ArF-immersion BARC BARC for ArF

step Time (sec) Speed (rpm) The accelerator (rpm / sec) Dispensing (cc) One 2.5 0 10,000 0.5 (Thinner) 2 1.5 900 10,000 0 3 9.5 1500 10,000 0 4 5.0 600 10,000 0.5 to 1 (PR) 5 5.0 1500 10,000 0 6 10.0 1000 10,000 0

PR1
(1.0 cc) PR2
(1.0 cc) PR3
(1.0 cc) PR4
(1.0 cc) 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 Comparative Example 2 X X X X X Comparative Example 3 X X X X X Comparative Example 4 ○ ○ △ △ △ Comparative Example 5 ○ ○ △ △ △ Comparative Example 6 ○ ○ X X X Comparative Example 7 ○ ○ X X X

[week]

◎: When the photoresist is 100% coated on the wafer after applying the thinner 0.5cc on the 8 inch wafer

○: RRC results When the photoresist is applied 95-99% on the wafer after applying 0.5cc thinner on the 8inch wafer

△: RRC results in the case that the photoresist is applied 90-94% on the wafer when the photoresist is applied after applying 0.5cc thinner on the 8inch wafer

X: When RRC result is applied thinner 0.5cc on 8inch wafer and photoresist is applied less than 90% on wafer

Referring to Table 4 above, the thinner compositions of Examples 1 to 7 according to the present invention exhibit excellent RRC performance for all photoresists. On the other hand, the thinner compositions of Comparative Examples 1 to 7 it was confirmed that the applicability of the photoresist is significantly lower than the thinner compositions of Examples 1 to 7. In addition, the thinner compositions of Examples 1 to 7 maintained an equally good RRC performance even when the rotational speed (rpm) condition of the RRC was changed. 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 the conventional thinner composition with respect to changes in process conditions.

Test Example  2: Thinner  Unnecessary of the composition Photoresist  Removal experiment

After applying the photoresist shown in Table 2 to the 8 inch silicon oxide substrate, the thinner compositions of Examples 1 to 7 and Comparative Examples 1 to 7 were subjected to the edge portion under the conditions described in Table 5 below. The experiment was performed to remove unnecessary photoresist of (Edge Bead Removing experiment: hereinafter referred to as EBR experiment). The thinner compositions of each of Examples 1 to 7 and Comparative Examples 1 to 7 were 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. It was made. In addition, the removal performance of unnecessary photoresist was evaluated using an optical microscope and a scanning electron microscope, and the results are shown in Table 6 below.

division Rotational speed (rpm) Time (sec) Dispense condition 300 ~ 2000 7 Spin coating Adjustable according to the photoresist thickness 15 EBR Condition 1 2000 20 EBR Condition 2 2000 25 Drying conditions 1300 6

PR1 PR2 PR3 PR4 BARC Example 1 ○ ○ ○ ◎ ○ Example 2 ○ ◎ ◎ ◎ ◎ Example 3 ○ ◎ ◎ ◎ ◎ Example 4 ○ ○ ◎ ◎ ◎ Example 5 ○ ○ ◎ ◎ ◎ Example 6 ◎ ◎ ◎ ◎ ◎ Example 7 ◎ ◎ ◎ ◎ ◎ Comparative Example 1 X △ △ △ X Comparative Example 2 X X △ △ X Comparative Example 3 X X X X X Comparative Example 4 ○ ○ △ △ △ Comparative Example 5 ○ ○ △ △ △ Comparative Example 6 ○ △ △ X X Comparative Example 7 ○ ○ X X X

[week]

◎: EBR line uniformity for the photoresist film after EBR is constant

○: Good linear state with EBR line uniformity of 75% or more on the photoresist film after EBR

(Triangle | delta): The shape of the edge part after EBR was distorted by the thinner melt action.

X: Tailing phenomenon occurs at the edge film after EBR

Referring to Table 6 above, the thinner compositions of Examples 1 to 7 according to the present invention exhibit excellent EBR performance for all photoresists. On the other hand, the thinner compositions of Comparative Examples 1 to 7 were found to have significantly reduced performance compared to the thinner compositions of the present invention according to Examples 1 to 7 in suppressing penetration into the photoresist. As a result, the thinner compositions of Examples 1 to 7 satisfy both the EBR performance of many types of photoresist and lower anti-reflective coating (BARC).

In addition, the thinner compositions of Examples 1 to 7 maintained an equally good EBR performance even when the rotational speed (rpm) condition of the EBR was changed. 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 the conventional thinner composition with respect to changes in process conditions.

Test Example  3: Photoresist  Evaluation of Coating Uniformity by Type

The coating uniformity for the five photoresists of Table 2 was tested using the thinner compositions of Examples 1-7 and Comparative Examples 1-7. After applying the photoresist on the 8-inch silicon oxide substrate according to the recipe as shown in Table 7 below, a total of 12 places in a X-shape, a total of 12 places (1 inch, 2 inches from the center of the wafer and the center of the wafer) 2) to determine whether the photoresist is uniformly applied and the results are shown in Table 8 below.

step Time (sec) Speed (rpm) The accelerator (rpm / sec) Dispensing (cc) One 5 0 10,000 2.0 (Thinner) 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

PR1 PR2 PR3 PR4 BARC Example 1 ○ ○ ○ ○ ○ Example 2 ○ ◎ ◎ ◎ ○ Example 3 ○ ◎ ◎ ◎ ○ Example 4 ○ ◎ ◎ ◎ ○ Example 5 ○ ○ ○ ◎ ○ Example 6 ◎ ◎ ◎ ◎ ◎ Example 7 ◎ ◎ ◎ ◎ ○ Comparative Example 1 X X △ △ △ Comparative Example 2 X X △ △ △ Comparative Example 3 X X △ △ △ Comparative Example 4 X △ ○ △ △ Comparative Example 5 X △ ○ △ △ Comparative Example 6 ○ ○ X X X Comparative Example 7 ○ ○ X X X

[week]

◎: when the standard deviation of the coating film thickness is 1% or less

○: when the standard deviation of the coating film thickness is 2% or less

(Triangle | delta): When the standard deviation of coating film thickness is 3% or less

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

Test Example  4: Photoresist  Depending on the type rework  Performance evaluation

The rework performance of the five photoresists of Table 2 was tested using the thinner compositions of Examples 1-7 and Comparative Examples 1-7. According to the recipe shown in Table 9 below, after the five photoresist was applied to the 8-inch silicon oxide substrate, the soft baking process was completed, and the rework process was performed using the thinner composition. In the case of BARC, the rework process was performed using each thinner composition without heat treatment after application.

The surface state of the reworked silicon oxide substrate was evaluated using TOPCON's surface scan equipment (Model name: WM-1500). The results are shown in Table 10 below.

step Time (sec) Speed (rpm) The accelerator (rpm / sec) Dispensing (cc) One 2 0 10,000 0 2 2 1000 10,000 0 3 4 1000 10,000 2.0 (Thinner) 4 9.5 4000 10,000 0 5 0 0 10,000 0

PR1 PR2 PR3 PR4 BARC Example 1 ◎ ◎ ◎ ◎ ◎ Example 2 ○ ◎ ◎ ◎ ◎ Example 3 ○ ◎ ◎ ◎ ◎ Example 4 ○ ○ ◎ ◎ ○ Example 5 ○ ◎ ◎ ◎ ◎ Example 6 ○ ◎ ◎ ◎ ◎ Example 7 ○ ◎ ◎ ◎ ◎ Comparative Example 1 X X △ △ △ Comparative Example 2 X X △ △ △ Comparative Example 3 X X △ △ X Comparative Example 4 △ △ △ ○ ○ Comparative Example 5 △ △ △ ○ ○ Comparative Example 6 ○ ○ X X X Comparative Example 7 ○ ○ X X X

[week]

◎: When the number of silicon oxide surface particles reworked as a result of surface scan is less than 1000

○: Surface scan results show that the number of reworked silicon oxide particles is more than 1000 and less than 2000

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

X: Surface scan shows more than 3000 reworked silicon oxide particles

Claims (11)

Thinner composition comprising alkoxy alkyl propionate, propylene glycol alkyl ether acetate and alkyl acetate. The thinner according to claim 1, comprising 25.0 to 45.0 wt% of alkoxy alkyl propionate, 15.0 to 60.0 wt% of propylene glycol alkyl ether acetate, and 25.0 to 65.0 wt% of alkyl acetate, based on the total weight of the thinner composition. Composition. The method of claim 1, wherein the alkoxy alkyl propionate is methoxy methyl propionate, methoxy ethyl propionate, methoxy propyl propionate, methoxy butyl propionate, ethoxy methyl propionate, ethoxy ethyl A thinner composition, characterized in that it is one selected from the group consisting of propionate, ethoxy propyl propionate and ethoxy butyl propionate. The thinner composition of claim 1, wherein the propylene glycol alkyl ether acetate has an alkyl group of 1 to 10 carbon atoms. The thinner composition according to claim 1, wherein the propylene glycol alkyl ether acetate is one selected from the group consisting of propylene glycol methyl ether acetate and propylene glycol ethyl ether acetate. The thinner composition of claim 1, wherein the alkyl acetate is n-butyl acetate. The thinner composition according to claim 1, further comprising an additive in the thinner composition. The method of claim 7, wherein the additive is selected from the group consisting of ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether and diethylene glycol diethyl ether. A thinner composition, characterized in that one kind. The thinner composition according to claim 7, wherein the additive is included in an amount of 10 to 1000 ppm by weight based on the total weight of the thinner composition. The thinner composition according to claim 1, wherein the thinner composition is used to reduce the amount of photoresist used. The method of claim 1, wherein the thinner composition is applied to the photoresist in an EBR process, a rework process, a wafer bottom surface cleaning process, or a photoresist coating process in the manufacturing process of the semiconductor device or the thin film transistor liquid crystal display device. The thinner composition used for the process of preprocessing the wafer surface.

Images