JP2007132996A - Cleaning and removing agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning and removing agent to be used for removing a photoresist remaining on the surface of a work surface after a photolithography process, the agent preventing corrosion of a conductive film and precipitation of an insoluble material even used at a high temperature, ensuring high safeness and resist removing property, having high cleaning power on a resist without corroding a conductive film, easy handling property and less adverse influences on a human body or an environment. <P>SOLUTION: A mixture consisting of 40 to 80 mass% of dimethylsulfoxide and 60 to 20 mass% of a cyclic compound expressed by a formula (1) such as caprolactone and/or propylene carbonate, or a composition containing the mixture as a main component is used as a resist cleaning and removing agent. In the formula (1), R represents CH<SB>2</SB>or O and R' represents an alkylene group which may have a substituent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a resist cleaning and removing agent. More specifically, the present invention relates to a cleaning remover used for removing a photoresist used for manufacturing a magnetic head element, a liquid crystal panel element, a semiconductor element and the like after a photolithography process.

For semiconductor elements such as magnetic head elements, liquid crystal panel elements, ICs, and LSIs, a resist is applied on an insulating film such as a conductive metal thin film, SiO ₂ film, or SiN film formed on a substrate, and a desired film is applied to the resist. The resist pattern is formed at a desired site by exposure and development through a mask on which the pattern is formed, and then etching or the like is performed using this resist pattern as a mask, and then the resist is removed. ing.

  Conventionally, an alkaline cleaning remover containing a water-soluble organic amine as an essential component has been used as a cleaning remover for removing the resist. Examples of such a cleaning remover include (a) amines such as monoethanolamine and ethylenediamine, (b) polar solvents such as dimethyl sulfoxide and N-methyl-2-pyrrolidone, and (c) surfactants. A resist stripping solution is known (see Patent Document 1), and the cleaning remover exhibits excellent resist stripping properties. However, in recent manufacture of magnetic head elements, liquid crystal panel elements, and semiconductor elements, a cleaning remover may be used at a high temperature of, for example, 80 ° C. to 90 ° C. In such a case, removal is performed even in a subsequent rinsing step. There is a problem that insoluble matter that is difficult to deposit is deposited on the surface of the non-cleaned material. Therefore, a resist cleaning and removing agent composed of dimethyl sulfoxide and ethylenediamine has been proposed as a cleaning agent free from such problems (see Patent Document 2). This cleaning agent does not deposit insoluble matter on the surface of the object to be cleaned even when used at a high temperature, and exhibits an excellent effect on the peelability of the resist, but exhibits strong irritation to the skin and eyes, Since it contains ethylenediamine having a strong sensitization property, there is a demand for a cleaner with higher safety.

  On the other hand, a resist remover that does not contain water-soluble organic amine as an essential component is also known. As such a cleaning agent, for example, 50% by mass or more of dimethyl sulfoxide contains 5 to 50% by mass of alcohol. There are resist cleaning removers (see Patent Document 3) and resist strippers (see Patent Document 4) containing dimethyl sulfoxide, amino alcohols and water.

  Although these cleaning removers and release agents have an excellent effect on resist releasability, the former resist cleaning remover has problems such as a low flash point and limited cleaning conditions and handling. In addition, the latter resist stripper contains water, so when using an object having a conductive film formed on the substrate as an object to be cleaned, the conductive film may be corroded to cause disconnection. There is a problem.

JP 63-231343 A Japanese Patent Laid-Open No. 11-133628 JP 63-163457 A Japanese Patent Application Laid-Open No. 07-69619

  Recently, the material of the conductive film has shifted to aluminum and copper which are easily corroded. These are easily corroded by water, and a decrease in product yield is a serious problem. In addition, pyrrolidones typified by N-methyl-2-pyrrolidone; ketones typified by acetone and methyl ethyl ketone; and methylene chloride have been widely used as components of detergents because of their high detergency. From the viewpoint of problems and safety to the human body, the use of these substances tends to be avoided.

  Under such circumstances, the present invention is a cleaning removal used when removing the photoresist remaining on the work surface after the photolithography process in the manufacture of magnetic head elements, liquid crystal panel elements, and semiconductor elements. An object of the present invention is to provide a cleaning agent that does not cause corrosion of a conductive film, does not precipitate insolubles even when used at high temperatures, and has high safety and resist removability.

  The present inventors have intensively studied to solve the above problems. As a result, it has been found that a cleaning remover comprising a specific compound such as ε-caprolactone and dimethyl sulfoxide achieves the above object, and has completed the present invention.

  That is, the present invention is characterized by comprising a mixture comprising 40 to 80% by mass of dimethyl sulfoxide and 60 to 20% by mass of a cyclic compound represented by the following formula (1), or a composition containing the mixture as a main component. Resist cleaning remover.

(In the formula, R is CH ₂ or O, and R ′ is an alkylene group which may have a substituent.)
Another aspect of the invention is a method for cleaning a resist-attached device, wherein the device to which a resist is attached is cleaned using the cleaning and removing agent of the present invention.

  The cleaning agent of the present invention exhibits excellent removal performance with respect to a resist. Moreover, the removal performance is maintained even when used at high temperatures, the conductive film is not corroded, it is easy to handle, and there are few adverse effects on the human body and the environment.

  The resist cleaning remover of the present invention comprises dimethyl sulfoxide and a cyclic compound represented by the above formula (1) (hereinafter, unless otherwise specified, the cyclic compound means one represented by the formula (1)). By using a mixture blended at a specific ratio as a main component, the removal performance of the resist is high over a wide operating temperature range, and it can be used for sidewall deposits generated by reactive ion etching, etc., and for resists altered by ion implantation. In contrast, it exhibits excellent removal performance.

  Here, the mixing ratio of dimethyl sulfoxide and the cyclic compound in the above mixture needs to be 40 to 80% by mass of dimethyl sulfoxide and 60 to 20% by mass of the cyclic compound based on the total mass of the mixture of the two components. . When the blending ratio of dimethyl sulfoxide is less than 40% by mass and the blending ratio of the cyclic compound exceeds 60% by mass, the resist cleaning and removing performance is deteriorated. On the other hand, when the blending ratio of dimethyl sulfoxide exceeds 80% by mass and the blending ratio of the cyclic compound is less than 20% by mass, the flash point becomes low, so that cleaning at high temperature becomes difficult. In addition, since the freezing point is increased, the operability is also deteriorated. From the viewpoint of effects, the content of dimethyl sulfoxide in the above mixture is preferably 40 to 70% by mass, and the content of cyclic compound is preferably 30 to 60% by mass.

The cyclic compound that is an essential component of the mixture is represented by the formula (1), but in the formula (1), the group “—R—” means —CH ₂ — or —O—, The group “R ′” means an alkylene group which may have a substituent. Examples of suitable groups as the group R ′ include —CH ₂ —, —CH (CH ₃ ) —, —CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) —, —CH ₂ CH ₂ CH ₂ —. _{, -CH 2 CH 2 CH 2 CH} 2 -, - CH 2 CH 2 CH 2 CH 2 CH 2 -, - CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 -, - CH 2 CH 2 CH (CH 2 CH ₂ CH ₃ ) — and the like.

  Examples of suitable cyclic compounds include lactones such as β-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone, hydroxy-γ-butyrolactone; ethylene carbonate, propylene carbonate, glutaric an And cyclic carbonates such as hydride, methyl glutaric anhydride, and glycerol 1,2-carbonate. These cyclic compounds can also be used as a mixture of different types. Among these, ε-caprolactone and propylene carbonate are particularly preferable from the viewpoints of detergency, safety, availability, and ease of handling.

  The cleaning and removing agent of the present invention may consist of only the above mixture, but may contain other components as long as this is the main component. However, when water is included, there is a problem that these metals are corroded when cleaning objects to be cleaned that have metal wiring or metal patterns on the surface thereof. The amount of water is preferably 1% by mass or less, particularly preferably 0.5% by mass or less.

  Examples of the “other components” that are preferably used include hydrocarbons such as glycol ethers, propylene glycol, and dibasic acid esters. Hydrocarbon is added to increase the solubility in the resist, and the amount added is preferably 0.1 to 20% by mass, particularly 1 to 10% by mass based on the mass of the entire cleaning remover. The components of the cleaning agent of the present invention, such as dimethyl sulfoxide, cyclic compounds, and hydrocarbons, are preferably pretreated by distillation or the like and purified, and particularly contain metal ions and anions. Is preferably 100 ppb or less on a mass basis of the entire cleaning remover.

  The resist cleaning and removing agent of the present invention can be used without any limitation for known photoresists. Preferably, it is most effective for positive photoresists for g-line, i-line, and excimer beam. Specific examples of the resin include novolac resins and polyhydroxystyrene resins.

The resist cleaning remover of the present invention is usually used in removing these photoresists developed on the substrate. In particular, the effects are most prominent when applied to a product that has been baked after development, and further subjected to dry etching such as reactive ion etching or processing such as ion implantation. Here, the substrate is not particularly limited, but a silicon wafer, glass or the like in which an insulating film such as SiO ₂ or a conductive film such as Al, Cu, Si or an alloy thereof is formed on the surface is generally used. Used for.

  When such an object to be cleaned is cleaned using the resist cleaning / removing agent of the present invention, the cleaning / removing agent of the present invention is used except that the cleaning / removing agent is used. It can be carried out. For example, a cleaning tank that does not allow the cleaning liquid to leak outside is provided, the cleaning agent of the present invention is stored, the object to be cleaned is immersed, and the attached resist is removed. Cleaning may be promoted by heating, ultrasonic waves, or the like during removal. The cleaning and removing agent of the present invention can be effective even when used at room temperature, but can be more effective when heated and used. In general, it is preferably used at a temperature of 20 to 95 ° C. After cleaning and removing the resist, a rinse step such as rinsing using isopropyl alcohol (IPA) vapor is performed as necessary, and the object to be cleaned is further dried.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

In addition, the symbol of each substance used by the Example and the comparative example is shown below.
DMSO: dimethyl sulfoxide ECL: ε-caprolactone GVL: γ-valerolactone 2PM: dipropylene glycol monomethyl ether PC: propylene carbonate DEGME: diethylene glycol monomethyl ether MEA: monoethanolamine NBEA: Nn-butylethanolamine PE61: Newpol PE61 (Sanyo Kasei surfactant)
DIW: ion-exchanged water Examples 1 to 5 and Comparative Examples 1 to 5
RCA cleaning (RCA cleaning is a cleaning method developed by RCA, and is a wet cleaning method for Si substrates based on ammonia / hydrogen peroxide cleaning (SC1) and hydrochloric acid / hydrogen peroxide cleaning (SC2). Then, a commercially available positive type photoresist (manufactured by Tokyo Ohka Kogyo Co., Ltd .: THMR-iP3300) is applied to a 4-inch silicon wafer treated with hexamethyldisilazane (HMDS) at a thickness of 1 μm and 2 at 90 ° C. Pre-baked for a minute. Subsequently, after developing by irradiating with i-line, rinsing was performed, and further post-baking was performed at 150 ° C. for 30 minutes.

  A test piece was cut out from the silicon wafer subjected to the above treatment with a diamond cutter, and the resist cleaning removal performance of the resist cleaning removal agent having the composition shown in Table 1 was evaluated by the following method. That is, a beaker containing 10 ml of a resist cleaning and removing agent was placed in a hot tub and kept at 50 ° C., the 1 cm square test piece was immersed in the beaker, taken out after 10 minutes, and the surface condition was observed visually and with a metal microscope. . The results are shown in Table 1. Evaluation was performed according to the following criteria.

  ○: The photoresist on the wafer surface is completely washed away.

  Δ: A part of the photoresist on the wafer surface remains undissolved.

  X: The photoresist on the wafer surface is hardly removed.

Example 6
In Example 1, the cleaning remover was evaluated in the same manner as in Example 1 except that the cleaning remover was kept at 80 ° C. The results are shown in Table 1.

Comparative Example 6
Instead of the cleaning remover of Example 1, a resist cleaning remover having the composition described in Table 1 was used, and a beaker containing 10 ml of the resist cleaning remover was placed in a hot tub and kept at 80 ° C. The cleaning remover was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Claims (3)

A resist cleaning and removing agent comprising a mixture comprising 40 to 80% by mass of dimethyl sulfoxide and 60 to 20% by mass of a cyclic compound represented by the following formula (1), or a composition containing the mixture as a main component.

(In the formula, R is CH ₂ or O, and R ′ is an alkylene group which may have a substituent.) The cleaning remover according to claim 1, wherein the cyclic compound represented by the formula (1) is ε-caprolactone and / or propylene carbonate. A cleaning method for equipment having a resist attached thereto, wherein the equipment having a resist attached is cleaned using the cleaning and removing agent according to claim 1.