KR20030023127A - Thinner composition for rinsing photoresist - Google Patents

Abstract

PURPOSE: A thinner composition for a cleansing a photosensitive resin is provided, which exhibits an excellent solubility to a photosensitive resin, and the improved stability owing to a low vapor pressure, a low volatility and a low toxicity. CONSTITUTION: The thinner composition comprises 10-90 wt% of propylene glycol monomethyl ether propionate; and at least one co-solvent. Preferably the co-solvent is selected from the group consisting of propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, n-butyl acetate, ethyl lactate, ethyl ethoxypropionate, methyl methoxypropionate, 2-heptanone and γ-butyrolactone.

Description

Thinner composition for cleaning photosensitive resin {THINNER COMPOSITION FOR RINSING PHOTORESIST}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to thinner compositions for cleaning photosensitive resins used in manufacturing processes, such as semiconductor devices and lithography, particularly thinner compositions in which at least one common agent is mixed with propylene glycol monomethyl ether propionate. The thinner composition is excellent in solubility in photosensitive resins, has low vapor pressure, low volatility, low toxicity, and exhibits excellent effects in removing unnecessary photoresist.

In general, a semiconductor integrated circuit or a flat panel display (FPD) circuit has an extremely fine structure and is manufactured through many steps. Such a microstructure circuit is formed by uniformly applying a photosensitive resin to an insulating film such as an oxide film formed on a substrate or a conductive metal film such as an Al alloy film, exposing / developing the photosensitive resin to form a predetermined pattern, and then The pattern of the photosensitive resin is transferred to the substrate by etching the insulating film or the conductive metal film using the photosensitive resin as a mask. Finally, the photosensitive resin pattern is removed using a stripping solution. During the manufacturing process, the photosensitive resin is coated on the substrate and then rotated to form a uniform coating film by centrifugal force, which is referred to as a 'rotating coating process'. In such an application process, unnecessary residual photosensitive resin in the form of particles due to centrifugal force exists at the edge portion and the rear portion of the substrate. Accordingly, in the process subsequent to the coating process, the remaining particulate photosensitive resin acts as a cause of defocus, scattering, etc. in the process of exposing the microstructure circuit, causing a cause of lowering the yield of the entire process. do.

In order to remove the residual photosensitive resin, an edge bead remover (EBR) is installed at the edges and rear portions of the substrate, and the residual photosensitive resin is sprayed by spraying a cleaning thinner composition through the nozzle of the apparatus. Will be removed. Factors that determine the performance as such a thinner composition include dissolution rate, volatility, viscosity, and linearity of the photoresist removal interface.

The performance determining element of the thinner is specified as follows.

Dissolution rate

The dissolution rate is an important factor for dissolving / removing the photosensitive resin and greatly affects the linearity of the photoresist removal interface. In other words, if the dissolution rate is too low relative to the volatilization rate, the flow phenomenon of partially dissolved photoresist tail called tailing may occur in the photosensitive resin applied to the substrate. In contrast, when the dissolution rate is too high, a photoresist over erosion phenomenon called a photoresist attack may occur in the rinse process of the photosensitive resin applied to the substrate. The tailing or attack phenomenon of the photosensitive resin is a cause of failure in the subsequent process. Therefore, the thinner for cleaning photosensitive resin requires an appropriate dissolution rate.

volatility

Volatility refers to how easily the thinner volatilizes and remains on the surface of the substrate after removing the photosensitive resin.If the volatility is too low, the thinner does not volatilize and induces a tailing phenomenon on the photoresist removal interface. In the subsequent process, it may cause a problem of acting as the interfering particles to reduce the productivity of the manufacturing process. In addition, when the volatility is too high, a phenomenon is formed in the photosensitive resin to which the substrate is rapidly cooled and applied, and when the thinner is sprayed through the nozzle of the edge bead remover (EBR), the photosensitive resin is completely removed. There is a problem that volatilization fails to dissolve / remove. It can also be volatilized into the atmosphere during handling, causing problems such as contamination of the clean room and the risk of explosion.

Viscosity

The viscosity of the thinner is a factor to be considered when spraying thinner through the nozzle of the photoresist removing device. If the viscosity is too high, the injection pressure may be too high when spraying through the nozzle. Dropped. In addition, when the viscosity of the thinner is too low, the photosensitive resin may not be concentrated on the photoresist stripping interface, which may cause a defect.

Linearity

The linearity of the photoresist removal interface is a factor related to all of the dissolution rate, volatility, and viscosity, and a clean interface may be obtained only when the dissolution rate, volatility, and viscosity are properly balanced. Therefore, the linearity can be said to be the biggest factor in determining the performance of the thinner composition for cleaning the photosensitive resin.

On the other hand, looking at the thinner compositions for cleaning the conventional photosensitive resin is as follows.

Ethers such as propylene glycol ether and propylene glycol ether acetate; Ether acetates; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; And thinner compositions using esters such as methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, and butyl acetate (Japanese Patent Laid-Open No. 63-69563): propyleneglycol monomethylether acetate (PGMEA) Known thinner compositions (Japanese Patent Laid-Open Publication No. Hei 4-49938) and thinner compositions using alkylalkoxypropionate (Japanese Patent Laid-Open Publication No. Hei 4-42523) and the like are known.

These conventional thinner compositions are mainly normal butyl acetate (n-BA), ethylene glycol monoethyl ether acetate (ECA), propylene glycol monomethyl ether acetate (PGMEA) and ethyl Although single solvents such as lactate (ethyl lactate, EL) have been widely used, such single solvents have problems in low dissolution rate, high volatility, and high viscosity.

In order to compensate for the shortcomings of these single compositions, a mixed solvent has been developed. For example, a thinner composition comprising a mixture of propylene glycol alkyl ether and alkyl 3-alkoxypropionate (JP-A-7-146562): propylene glycol And mixtures of alkyl ethers, butyl acetate and ethyl lactate (JP-A-7-128867).

In addition, U.S. Patent No. 4,983,490 discloses a thinner composition which is a mixed solvent of propylene glycol alkyl ether acetate and propylene glycol alkyl ether. There is a risk of harm.

Moreover, conventional mixed solvents are problematic in solubility, volatility, toxicity, interface linearity, and cleaning effects, and there are many difficulties in applying them to the manufacture of semiconductor devices that are becoming highly integrated.

The present invention has been made to solve the problems posed by the conventional photosensitive resin cleaning thinner and a mixed solvent as described above, the present invention

First, it has excellent solubility in washing photosensitive resin,

Secondly, it has low vapor pressure and low toxicity, so there is no risk of contamination and explosion in the clean room, and there is no danger of harming worker's health,

Third, the lower the viscosity can lower the injection pressure when spraying through the nozzle, thereby reducing the amount of thinner used to improve the economics,

Fourthly, an object of the present invention is to provide a thinner composition for cleaning photosensitive resin which exhibits a clean linearity of the photosensitive resin interface when sprayed through the nozzle of the photosensitive film removing apparatus.

1 to 9 are optical micrographs inspecting the degree of linearity with respect to each embodiment and comparative example of the thinner composition for cleaning photosensitive resin according to the present invention.

In order to achieve the above object, the thinner composition for cleaning a photosensitive resin according to the present invention provides a thinner composition in which at least one common agent is mixed with 10 to 90% by weight of propylene glycol monomethyl ether propionate.

Preferably the co-agent is propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, normal butyl acetate, ethyl lactate, ethyl ethoxy propionate, methyl methoxy propionate, 2-heptanone, gamma butyro Suitable is selected from the group consisting of lactones and the like.

More preferably, the thinner composition is a two-component or three-component thinner composition in which 10 to 50% by weight of propylene glycol monomethyl ether propionate and one or two of the coagents are mixed.

Since the thinner composition according to the present invention has excellent solubility in photosensitive resin, moderate volatility, and low toxicity, the thinner composition may be applied to the edge portion and the rear portion of the substrate in the rotation coating process of the photosensitive film during the manufacturing process of semiconductor devices and lithography. It exerts an excellent effect in removing the unnecessary photoresist film generated, and in the unnecessary edge bead remover (EBR) of the edge portion, clean linearity with respect to the interface of the photoresist film when spraying the thinner composition of the present invention through the nozzle of the device (linearity) can be obtained.

Therefore, when the thinner composition for cleaning the photosensitive resin according to the present invention is used, productivity is improved in semiconductor devices and plate printing processes due to effects such as an increase in edge bead rinse treatment characteristics and an improved cross section of the photosensitive resin. You can.

The propylene glycol monomethyl ether propionate in the thinner composition of the present invention has excellent solubility in various resins and low viscosity. It also has high stability and low volatility when exposed to air. In addition, LD50 (oral) is 12g / kg, there is little discomfort due to toxicity and odor, which is environmentally friendly. Its physical properties include boiling point 160 ° C, flash point (measured by closed cup method) 56 ° C, viscosity (at 25 ° C) 1.18 cps, vapor pressure (at 20 ° C) 0.9mmHg, and solubility parameter 4.8.

However, when only the propylene glycol monomethyl ether propionate is used as a thinner for cleaning the photosensitive resin, there is a problem that the volatility is low compared to the high dissolution rate. Also, due to the low viscosity, the propylene glycol monomethyl ether propionate cannot be concentrated at the interface when removing the photoresist film, thereby causing a defect. There is a problem.

Therefore, it is preferable to prepare a thinner composition by mixing a common agent that can compensate for the disadvantage of using propylene glycol monomethyl ether propionate alone as a thinner for washing photosensitive resin.

In order to eliminate the disadvantages of propylene glycol monomethyl ether propionate as described above, exemplified as a material that can be used as a co-agent.

First, propylene glycol monomethyl ether, which is used as a mixing agent in the thinner composition of the present invention, has excellent solubility in phenolic resins and photoactive substances in photosensitive resins, and LD50 (oral), which shows toxicity, is 4.4 g / kg, When inhaled by humans, it is rapidly decomposed into propylene glycol and alcohol, so it is safe for workers. However, due to the high vapor pressure, high volatility gives workers unpleasant odor due to bad smell when used for a long time, and high viscosity makes it difficult to use alone. Physical properties are boiling point 132.8 ° C, flash point (measured by closed cup method) 32 ° C, viscosity (at 25 ° C) 1.86 cps, vapor pressure (at 25 ° C) 12.6mmHg, surface tension 26.5 dyne / cm 2, solubility parameter 10.4.

In addition, propylene glycol monomethyl ether acetate, normal butyl acetate, ethyl lactate, ethyl ethoxy propionate, methyl methoxy propionate, 2-heptanone, gamma butyrolactone, etc., which are used as co-agents in the present invention, are also propylene. Problems such as glycol monomethyl ether are difficult to use alone.

Therefore, in the present invention, the propylene glycol monomethyl ether propionate is used as a main component, and the co-agent is prepared by mixing at least one ratio. The thinner composition has high solubility in photosensitive resin, moderate volatility, and viscosity. Excellent properties for the linearity of the oil-retaining and photosensitive resin removal interface. In addition, the mixed composition can reduce the discomfort caused by the smell in terms of the environment, there is little risk of harm to the health and explosion of workers due to low toxicity / low flash point in terms of stability.

Hereinafter, the thinner composition for cleaning the photosensitive resin according to the present invention may be more clearly understood through the following examples.

EXAMPLE

1. Preparation of thinner composition

A thinner composition obtained by mixing propylene glycol monomethyl ether propionate and a co-agent in a predetermined ratio was prepared in Examples 1 to 28 with different composition ratios, and Comparative Compositions 1 and 2 were prepared. Indicated on

Table 1 Preparation of Thinner Compositions of Each Example and Comparative Example (Unit: Weight%)

division The composition ratio of each thinner division The composition ratio of each thinner Example 1 PMP: PGME = 90:10 Example 16 PMP: MMP: EL = 35:50:15 2 PMP: PGME = 80:20 ˝ 17 PMP: MMP: EL = 55:30:15 ˝ 3 PMP: PGME = 70:30 ˝ 18 PMP: PGME: MAKN = 10:70:20 4 PMP: PGME = 50:50 ˝ 19 PMP: PGME: MAKN = 10:80:10 ˝ 5 PMP: PGME = 30:70 ˝ 20 PMP: PGME: nBA = 10:80:10 ˝ 6 PMP: PGME = 20:80 ˝ 21 PMP: PGME: nBA = 30:60:10 ˝ 7 PMP: PGME = 10:90 ˝ 22 PMP: PGME: nBA = 50:40:10 8 PMP: EL = 25:75 ˝ 23 PMP: EA: GBL = 30: 65: 5 ˝ 9 PMP: EL = 75:25 ˝ 24 PMP: EA: GBL = 60: 35: 5 ˝ 10 PMP: MMP = 75:25 ˝ 25 PMP: EA: GBL = 80: 15: 5 ˝ 11 PMP: MMP = 25:75 ˝ 26 PMP: PGMEA: EA = 10:10:80 ˝ 12 PMP: EEP: EL = 20:60:20 ˝ 27 PMP: PGMEA: EA = 40:10:50 ˝ 13 PMP: EEP: EL = 40:40:20 ˝ 28 PMP: PGMEA: EA = 60:10:30 ˝ 14 PMP: EEP: EL = 60:20:20 Comparative Example 1 EL: EEP = 20:80 ˝ 15 PMP: MMP: EL = 25:60:15 2 EL: PGME = 50:50 Where PMP: propylene glycol monomethyl ether propionate PGME: propylene glycol monomethyl ether EL: ethyl lactate GBL: gamma butyrolactone MMP: methyl methoxy propionate EEP: ethyl ethoxy propionate nBA: normal butyl Acetate EA: ethyl acetate PGMEA: propylene glycol monomethyl ether acetate MAKN: 2-heptanone

2. Evaluation of Dissolution Rate of Thinner Composition for Positive Photosensitive Resins

Among the photosensitive resin compositions generally used, a g-line positive photosensitive resin composition was applied to a 4 inch silicon oxide wafer, soft baked at 110 ° C. for 90 seconds, and then cut into 1 cm × 1 cm specimens at room temperature. Precipitated in each thinner solution of>, the time the photosensitive resin is completely removed was measured, and the resulting dissolution rate is shown in Table 2 below.

[Table 2] Evaluation of dissolution rate of each thinner composition for the photosensitive resin (unit: Å / sec)

division Melting Speed division Melting Speed Example 1 7200 Example 16 10358 2 7568 ˝ 17 9238 ˝ 3 8625 ˝ 18 13756 4 10781 ˝ 19 14820 ˝ 5 12778 ˝ 20 14532 ˝ 6 13687 ˝ 21 12456 ˝ 7 15682 ˝ 22 10220 8 10835 ˝ 23 15202 ˝ 9 8423 ˝ 24 10462 ˝ 10 9232 ˝ 25 9230 ˝ 11 12330 ˝ 26 14438 ˝ 12 12330 ˝ 27 11897 ˝ 13 9456 ˝ 28 8432 ˝ 14 8720 Comparative Example 1 9945 ˝ 15 12563 2 8222

3. Volatile Evaluation of Each Thinner Composition

To measure the volatility of each of the thinner compositions, 1 mL of each thinner composition was dropped onto a 4 inch wafer using a spin coater (Miders), and then the edge of the wafer was changed at a rotation speed of 1,000, 2,000, or 3,000 rpm. The time taken for the thinner to be completely volatilized was measured, and the results are shown in Table 3 below.

TABLE 3 Volatile Evaluation of Each Thinner Composition (Unit: sec)

division Volatility time division Volatility time 1000 rpm 2000 rpm 3000 rpm 1000 rpm 2000 rpm 3000 rpm Example 1 26.3 13.1 9.2 ˝ 16 23.6 11.7 8.2 2 25.1 12.5 8.8 ˝ 17 25.8 12.7 8.3 ˝ 3 24.2 12.0 8.5 ˝ 18 11.6 6.1 4.6 4 22.1 11.1 8.1 ˝ 19 11.1 6.0 4.5 ˝ 5 20.1 10.1 7.1 ˝ 20 17.1 8.6 6.4 ˝ 6 19.1 9.6 6.8 ˝ 21 19.2 9.6 6.8 ˝ 7 18.0 9.0 6.4 ˝ 22 21.2 10.6 7.5 8 34.9 16.4 11.2 ˝ 23 16.2 7.9 5.6 ˝ 9 30.2 14.8 10.4 ˝ 24 23.4 11.5 8.0 ˝ 10 24.6 12.2 8.6 ˝ 25 28.2 13.8 9.7 ˝ 11 19.2 9.7 6.7 ˝ 26 7.4 3.6 2.7 ˝ 12 34.8 16.9 11.8 ˝ 27 14.5 7.2 5.1 ˝ 13 33.1 16.1 11.3 ˝ 28 19.3 9.5 6.8 ˝ 14 31.3 15.3 10.7 Comparative Example 1 36.0 17.4 12.1 ˝ 15 22.6 11.2 7.8 2 48.2 23.8 11.7

4. Evaluation of linearity of each thinner composition

Each of the thinner compositions was used to remove unnecessary photosensitive resin at the edge, and the linearity of the interface was measured. After applying a photosensitive resin at 1500 rpm on a 4 inch wafer using a spin coater (Meiders), the photosensitive resin was subjected to ESP nozzle pressure of 1.0 kg.f / cm, thinner flow rate 12 mL / min, and spin coater 2,000 rpm. After removing the resin, the treated cross section was measured using an optical microscope, and the results are shown in Table 4 below and FIGS. 1 to 9.

TABLE 4 Evaluation of linearity of each thinner composition

division Linearity Corresponding drawing division Linearity Corresponding drawings Example 4 △ - Example 15 ◎ 6 ˝ 5 ◎ 1 ˝ 19 ◎ - ˝ 6 ◎ 2 ˝ 21 ◎ 7 ˝ 7 ◎ 3 ˝ 23 ◎ - 8 △ - ˝ 27 ◎ - ˝ 11 ◎ 4 Comparative Example 1 △ 8 ˝ 12 △ 5 2 Ⅹ 9 Here,?: The processing cross section is clean. (High linearity) △: Treated section is slightly eroded. (Linearity is normal, attack phenomenon) Ⅹ: Excess residue remains on the treated section. (Low linearity, tailing phenomenon)

The thinner composition for cleaning the photosensitive resin of the present invention is as compared to Comparative Examples 1 and 2 as shown in <Table 2> to <Table 4> showing the experiments and the results for the dissolution rate, volatility, and linearity. It can be seen that each characteristic is excellent. Although similar to the comparative example in individual performance, it can be said to be superior to the comparative example overall. In particular, as described above, since the linearity of the photoresist removal interface of the thinner composition is a factor related to all of dissolution rate, volatility, and viscosity, it can be seen in the optical micrographs of the degree of linearity of Table 4 and FIGS. 1 to 9. As can be seen, it is remarkably superior to Comparative Examples 1 and 2. In addition to the optical micrograph of each embodiment according to the present invention shown in the accompanying Figures 1 to 9 also showed similar linearity in the other embodiments.

As mentioned above, the scope of protection of the present invention is not limited by each embodiment of the thinner composition.

As described above, the thinner composition for cleaning the photosensitive resin according to the present invention is

First, it has excellent solubility in washing photosensitive resin,

Secondly, it has low vapor pressure and low toxicity, so there is no risk of contamination and explosion in the clean room, and there is no danger of harming worker's health,

Third, the lower the viscosity can lower the injection pressure when spraying through the nozzle, thereby reducing the amount of thinner used to improve the economics,

Fourth, there is an effect of providing a thinner composition for cleaning the photosensitive resin showing a clean linearity of the photosensitive resin interface when spraying through the nozzle of the photosensitive film removing device.

Claims (3)

10 to 90% by weight of propylene glycol monomethyl ether propionate prepared by mixing one or more common agents for cleaning the photosensitive resin thinner composition. The method of claim 1, wherein the common agent Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, normal butyl acetate, ethyl lactate, ethyl ethoxy propionate, methyl methoxy propionate, 2-heptanone, gamma butyrolactone The thinner composition for cleaning photosensitive resin, characterized in that the. The method according to claim 1 or 2, 10 to 50% by weight of the propylene glycol monomethyl ether propionate mixed in the thinner composition, the co-agent is mixed with one or two to form a two- or three-component thinner composition for cleaning the photosensitive resin Thinner composition.