JPS63159849A - Photoresist release agent composition - Google Patents

Abstract

PURPOSE:To improve peel strength of the titled composition and to enable cleaning of a released surface by incorporating a prescribed amount of dimethylsulfoxide and water and the prescribed amount of a surfactant based on the total amount of the titled composition. CONSTITUTION:The titled composition is applicable to remove the photoresist which is usable to the production of an integrated circuit and has settled its affairs. The titled composition contains >=50vol.% dimethylsulfoxide and 5-50vol.% water based on the total volume of the titled composition, thereby obtaining the excellent peel strength. And, the titled composition contains >=0.01vol.% the surfactant, thereby removing a dust stuck on the released surface and cleaning the surface of an inorg. substrate after peeling.

Description

Detailed Description of the Invention (Field of Application of M Tojo) The present invention relates to photoresists used in integrated circuit manufacturing;
The present invention relates to a resist stripping composition used for removing 4IK positive photoresist after use.

A photoresist is a photosensitive resin used in the manufacture of integrated circuits, and is used to perform operations such as etching and implanting impurities at desired locations on an inorganic substrate such as a silicon wafer. Photoresists can be roughly divided into positive types, where areas exposed to light dissolve easily in developer, and negative types, which are used differently depending on their characteristics. The most common positive resist is one in which quinonediazide molecules are bonded to an alkali-soluble novolac resin via a sulfone group.The resist has a high W4 image resolution, and is therefore suitable for the recent demand for higher integration. Its usage is rapidly increasing as a suitable resist.

In the manufacturing process of integrated circuits, a resist is uniformly applied onto an inorganic substrate, exposed through a photomask, and subsequently developed with a suitable solvent to form a fine pattern on the inorganic substrate. In the subsequent etching and impurity implantation steps, this fine resist pattern becomes a protective film.
A fine electronic circuit is formed on the inorganic substrate, and then the unnecessary resist coating is peeled off.

(Prior Art) Resist stripping KFi and various organic or inorganic chemicals have been studied and used. Examples of organic systems that are practically used include stripping agents based on organic sulfonic acids (Japanese Patent Publication No. 51-72503, etc.), and stripping agents based on alkylene glycols (Japanese Patent Publication No. 43-7695, etc.). There is, maku.

For inorganic systems, there are nine methods including a method using a mixture of sulfuric acid and hydrogen peroxide (piranha cleaning), and a combination of cleaning with ammonia and hydrogen peroxide, hydrochloric acid and hydrogen peroxide, and hexacid (RCA cleaning). be.

Organic release agents generally have a low #I release force and rarely exhibit a release effect, especially for resists (K) that have undergone significant deterioration and hardening during processes such as selective ion implantation. Stripping agents based on organic sulfonic acids are most commonly used in organic systems, but they are corrosive to metals and often cause problems in resist stripping from wafers with aluminum wiring. Furthermore, it is a safety problem because it usually contains toxic phenol. 1-For stripping of positive resist, dimethyl sulfoxide, N, N-
It has been announced that compositions based on high Q polar solvents such as dimethylformamide are effective (US P 450).
46B1, USP 4405029, JP 60-66424, etc.), these compositions.

Generally not put into practical use. This is thought to be because the resist has insufficient peeling force and also has almost no dissolving power for ionic substances such as metal ions. Metal ions that have adhered to the inorganic substrate for some reason seep into the inorganic substrate during high-temperature treatment such as a diffusion process.
These contaminants must be completely removed during the resist stripping process because they can cause fatal defects in the performance of integrated circuits.

On the other hand, inorganic stripping agents have a high resist stripping power.

It has excellent ability to remove ionic substances, but it has a high a degree of #! Since R1 alkali and hydrogen peroxide are used, there is a high risk in terms of work safety, and further disadvantages include that hydrogen peroxide decomposes over time and that it is difficult to control the concentration of the stripping agent.

In addition, because of its strong corrosivity to metals, it cannot be applied to resist stripping with aluminum wiring.

(Problems to be Solved by the Invention) As mentioned above, conventional resist stripping agents, both organic and inorganic stripping agents, have their own drawbacks, and none that are fully satisfactory as resist stripping agents have been obtained. do not have.

(Friendly means of solving problems) The inventors aim to solve the above problems.

It has high resist peeling power and ionic substance dissolving power,
As a result of intensive research into a highly safe resist stripping agent that is not corrosive to metals, we have completed the present invention.

That is, 1 the present invention is a photoresist stripper composition characterized in that it contains at least 50 volumes of dimethyl sulfoxide and 5 to 5 degrees of water based on the total amount of the composition; Ta.

A photoresist stripping composition characterized in that, in addition to the dimethyl sulfoxide and water, a surfactant is contained in an amount of 0.01 volume or more based on the total amount of one composition.

(Function) The uninvented stripping agent composition is also effective against positive resists that have undergone deterioration and hardening during the mulberry circuit manufacturing process.

Dimethyl sulfoxide has an excellent release force that cannot be predicted from the release force of water alone. The preferred dimethyl sulfoxide concentration of the composition of the present invention is 60-9
0 valley t% in this range.

A strong peeling force comparable to cleaning with a mixture of sulfuric acid and hydrogen peroxide (Piranha α#), which is said to be the most powerful II release agent at present, can be obtained. When the volume of dimethyl sulfoxide contained in the composition of the present invention is less than 50 volumes, the peeling force is significantly reduced.

Furthermore, the composition of the present invention exhibits excellent dissolving power for ionic substances, and can completely clean the surface of an inorganic substrate after peeling. The dissolving power of ionic substances is
When the water content is less than 5 volumes, the water content decreases rapidly.

Furthermore, since the composition of the present invention has no corrosivity to common metals, such as aluminum, it can also be used for resist stripping of wafers with aluminum wiring.

Furthermore, high safety is also a feature of the present invention.

Dimethyl sulfoxide has low toxicity (LD, rat oral tar/J), has a high flash point (95G), and has a K of 1.
The composition of the present invention is highly resistant to ignition due to the effect of water.

(1) The composition of the present invention is liquid at room temperature.

Pure dimethyl sulfoxide (melting point 18.5 C) K
Comparatively easy to handle.

Even though integrated circuits are manufactured in strictly controlled clean rooms, it is inevitable that small particles of dust will adhere to their surfaces. When the composition of the present invention contains a surfactant of 0.01 volume or more, such dust can be removed from the surface and stably dispersed in the stripping agent, so that the surface of the inorganic substrate after stripping can be It is possible to make it cleaner. As a surfactant.

Most preferred are nonionic ones that do not contain metal ions, such as fatty acid monoglycerin ester, fatty acid polyglycol ester, fatty acid sorbitan ester, fatty acid sucrose ester, fatty acid alkanolamide, and fatty acid polyethylene glycol condensate.

Fatty acid amide/polyethylene glycol condensate.

Aliphatic alcohol/polyethylene glycol condensates, aliphatic amine/polyethylene glycol condensates, aliphatic mercaptan/polyethylene glycol condensates, alkylphenol/polyethylene glycol condensates, polypropylene glycol/polyethylene glycol condensates, etc., with an HLB of 7 or more. is exemplified.

However, the composition of the present invention may also include a miscible third component. As the fifth component, alkylene glycols such as propylene glycol, alkylene glycol ethers such as propylene glycol monomethyl ether, etc. , alcohols having 4 or more carbon atoms, and the like.

(Example) The present invention will be explained in more detail with reference to Examples below.

Examples 1 to 4 Commercially available positive resist [Tokyo Ohka Kogyo Co., Ltd. OFPR-
8003 was coated on a 5-inch silicon wafer to a thickness of about 1.5μ, baked at 140C for 30 minutes, and then an ion implantation operation was performed. fL < Altered and hardened to obtain 9 resist. 13X with this wafer tube diamond cutter
25 ms [Cut and make a sample.

The release agent composition (formulation composition shown in Table IK) was placed in a 50 SD test tube for 10 minutes, heated in a 100 C oil bath for 15 minutes or more, and then subjected to the test.

For peeling performance, a sample was placed in a heated release agent composition, and after standing for 5 minutes, the peeling condition [1' was visually evaluated as follows, and the results are summarized in Table 1K. The symbols in the table have the following meanings.

Child 0 was completely detached.

ΔThere is some peeling residue in some parts.

× indicates that the film has not been peeled off at all.

In addition, dimethyl sulfoxide in Table 1 is abbreviated as DMSO.

Table 1 Comparison, Comparative Examples 1 to 4 The release performance of the release agents shown in Table 1 and Table 2 was evaluated in the same manner as in Examples 1 to 4, and the results are shown in Table 2.

Table 2 ]11[1 Dodecylbenzenesulfonic acid, phenol.

Mixture of chlorinated solvent 1.2 Mixture of alkylene glycol and organic alkali Example 5~) Spray approximately 0.2f of 5tlI salt water uniformly onto a 5-inch silicon wafer using a 'Jt atomizer, and dry in a hot air dryer at 140C. Let dry for 30 minutes. This wafer was heated to 100C with a release agent (mixture composition shown in Table 5VC) 100dK5
After soaking for 1 minute and rinsing with the same stripping agent 100 at room temperature, the amount of ionic residue was evaluated according to MIL-P-28809AK. That is, after rinsing, the nine wafers were washed with a 75-volume inproper tool and a 25-volume solution of distilled/deionized water (resistivity: 6 x 10 Ωm).
1) Rinse with 100- and measure the electrical conductivity of this solution.9.

High resistivity means low ionic residue. The measurement results of resistivity are shown in Table 3.

Table 3 Comparative Example 5 The ionic residue was evaluated in the same manner as in Examples 5 to 7, and the results are shown in Table 4.

Table 4

Claims (2)

[Claims] (1) A photoresist stripping composition characterized in that it contains at least 50% by volume of dimethyl sulfoxide and 5 to 50% by volume of water based on the total amount of the composition. (2) 50% by volume or more of dimethyl sulfoxide and 5 to 50% by volume of water based on the total amount of the composition;
1. A photoresist stripper composition comprising 0.01% by volume or more of a surfactant.