JPH0594024A - Developing solution for positive type photoresist - Google Patents

Abstract

PURPOSE:To obtain the developing solution capable of forming a resist pattern high in resolution, ultraminute in size, small in dispersion in pattern size and excellent in the profile by adding a kind of sugar and the like into an aqueous solution of a specified ammonium hydroxide. CONSTITUTION:The developing solution contains an aqueous solution of the 1-10weight% quaternary ammonium hydroxide represented by formula I and the 0.1-3weight% sugar or sugar alcohol. In formula, R is 1-3C alkyl or alkoxy, and R<1> is 1-3C alkyl. The quaternary ammonium hydroxide is tetramethyl-, tetraethyl-, or trimethyl(2-hydroxyethyl) ammonium hydroxide, and it is used generally in an amount of 1-10weight% of the total solution and practically, each in a suitable concentration dependent on compound to be used. The sugar or sugar alcohol is xylitol, sorbitol, or sucrose.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive photoresist developer, and more particularly to a developer obtained by mixing a quaternary ammonium hydroxide aqueous solution with a saccharide or sugar alcohol, and particularly at a high resolution. It is a positive photoresist developer capable of forming a fine pattern, having a small variation in the pattern size, and providing an excellent pattern profile, and is useful for the production of ultra-fine processed semiconductor integrated circuits.

[0002]

2. Description of the Related Art Recent developments in the electronic industry have been remarkable, and recent semiconductor integrated circuits are highly integrated as represented by VLSI, and along with that, the minimum line width at the time of drawing a circuit is gradually made finer, resulting in a resist pattern. There is a strong demand for the accurate formation of A positive resist can meet such a demand, and it has a resolution higher than that of the negative resist used conventionally. A typical positive resist is one containing both an alkali-soluble novolac resin as a base and a naphthoquinonediazide compound as a photodecomposing agent. An alkaline aqueous solution is generally used as a developer for the naphthoquinone azide-based positive resist, but it is preferable to use an alkaline aqueous solution containing no metal ion in the developer when manufacturing a semiconductor integrated circuit device. Needless to say. Therefore, an organic alkaline developer containing no metal ion, for example, an aqueous solution of tetramethylammonium hydroxide or choline is known. (IBM
"Technical Disclosure Bulettin" Vol. 13, No. 7,
(Page 2009, 1970, U.S. Pat.No. 4,239,661)

However, when a pattern having a fine line width is drawn using an aqueous solution of tetramethylammonium hydroxide or choline, the resist profile and the dimensional control accuracy are extremely lowered. Therefore, the alkali concentration of the developing solution is increased or the developing time is lengthened in order to increase the resist sensitivity, but it is not possible to achieve a sufficient effect on the so-called throughput. In addition to the above, various additives, such as a surfactant, to the quaternary ammonium hydroxide aqueous solution as an improvement for improving the resolution.
It has been proposed to add an organic compound. A surfactant added is, for example, JP-A-58-914.
3, JP-A-61-70551, JP-A-61-167.
48, JP-A-61-151537, JP-A-61-2
32453, JP 61-232454, JP 6
No. 2-32452, JP-A-62-32454, JP-A-62-47125 and the like, and examples of surfactants to which other organic compounds such as alcohol and hydrocarbon are added include JP-A-62-232453, JP-A-58-57128 and the like can be mentioned. However, even in these cases, there are merits and demerits in each case, and it is hard to say that the resolution, dimensional accuracy, etc. are not necessarily satisfactory in lithography with a fine line width.

The present inventors have previously proposed a positive photoresist developer in which hydrazine or a combination of hydrazine and a surfactant is mixed with an aqueous quaternary ammonium hydroxide solution. This is an excellent developer that produces a fine line width pattern profile and generates less scum compared to conventional alkaline developers, but in the case of obtaining more advanced ultrafine line width lithography, resolution and dimensional accuracy The stability of is not good enough yet.

On the other hand, the present inventors have blended a quaternary ammonium hydroxide aqueous solution with a saccharide or sugar alcohol as a surface treatment liquid for preventing aluminum corrosion caused by halogen in an aluminum wiring board by dry etching. An aqueous solution was previously proposed (Japanese Patent Application No. 2-14554).

[0006]

In view of the above circumstances, the present invention can provide an excellent resist pattern profile having high resolution and can form an ultrafine pattern with a small pattern size variation. To provide a mold photoresist developer.

[0007]

Means for Solving the Problems The present inventors have conducted a multifaceted study on organic alkaline positive resist developers, and added saccharides or sugar alcohols to an aqueous quaternary ammonium hydroxide solution. It was found that the aqueous solution enables stable and highly precise ultrafine processing, and gives an excellent pattern profile. That is, the present invention provides a compound represented by the general formula: [(R ¹ ) ₃ NR] ⁺ · OH ⁻ (wherein R is an alkyl group having 1 to 3 carbon atoms or a hydroxy-substituted alkyl group having 1 to 3 carbon atoms). , R ¹ represents an alkyl group having 1 to 3 carbon atoms) and a quaternary ammonium hydroxide aqueous solution of 1 to 10% by weight and a saccharide or sugar alcohol of 0.1 to 3% by weight. Mold photoresist developer.

In the present invention, the quaternary ammonium hydroxide represented by the above general formula is a tetraalkylammonium hydroxide having an alkyl group having 1 to 3 carbon atoms or a trialkylammonium hydroxide in which R is a hydroxy-substituted alkyl group. Alkyl (hydroxyalkyl) ammonium hydroxide,
Specifically, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, trimethylethylammonium hydroxide, trimethyl (2-hydroxyethyl) ammonium hydroxide, triethyl (2- Hydroxyethyl) ammonium hydroxide, tripropyl (2-hydroxyethyl) ammonium hydroxide, trimethyl (1-hydroxypropyl) ammonium hydroxide and the like can be mentioned.
Among these, tetramethylammonium hydroxide (hereinafter sometimes referred to as “TMAH”) and trimethyl (2-hydroxyethyl) ammonium hydroxide (hereinafter sometimes referred to as “choline”) are particularly preferable. ..

The above quaternary ammonium hydroxide is generally selected in a concentration range of 1 to 10% by weight in the total solution, and in actual use, an appropriate concentration is selected depending on the kind of compound used. .. For example, in the case of choline or tetraethylammonium hydroxide, it is necessary that the concentration is at least 5% by weight, and if it is lower than 5% by weight, the development cannot be sufficiently performed, and sometimes the development cannot be performed at all. However, it is not formed, and scum occurs, so that a good pattern cannot be formed. TMAH
In the case of, a concentration in the range of 3% by weight to 4% by weight is selected, and at a high concentration of 5% by weight such as choline, the film thickness reduction rate of the unexposed portion becomes too fast and the resist dissolves to form a fine pattern. I can't. In order to obtain a stable and good pattern profile as described above, it is necessary to appropriately select the concentration used depending on the compound used.

Next, the saccharides or sugar alcohols used together with the quaternary ammonium hydroxide in the present invention are saccharides such as monosaccharides and polysaccharides. Specifically, for example, they have 3 to 6 carbon atoms. Glycerin aldehyde, threose, erythrose, arabinose, xylose, ribose, ribulose, xylulose, glucose, mannose, galactose, tagatose, allose, gulose,
Examples thereof include idose, talose sorbose, psicose and fructose, and examples of the sugar alcohol include threitol, erythritol, adonitol, arabitol, xylitol, talitol, sorbitol, mannitol, iditol and dulcitol. In addition, disaccharides such as sucrose, maltose, lactose and morbiose can also be used. These sugars or sugar alcohols are generally used in a concentration range of 0.1 to 3% by weight, preferably 0.5 to 3% by weight in the total solution. If it is lower than the above range, it becomes difficult to form an ultrafine pattern with high accuracy, while if the concentration is higher than 3% by weight, the film reduction rate of the exposed portion of the resist is reduced and a good pattern is not formed. Cannot function as.

The developing solution in the present invention can be applied to any method such as a dipping method, a spray method and a paddle method, and the temperature, time and the like during development are appropriately selected according to the kind of resist, but for example, usually When a resist consisting of an alkali-soluble novolac resin containing a naphthoquinone azide compound is used to develop by a dipping method, the pattern formation that is generally satisfactory at the temperature (room temperature) and the development time that have been used up to now can be obtained. Is possible.

The present invention will be more specifically described below with reference to examples.

【Example】

Example 1 [Preparation of test resist pattern] OFPR-80 containing an alkali-soluble novolac resin and a naphthoquinonediazide compound as constituents on a 3-inch silicon wafer.
0 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) with a spinner to a film thickness of 1.2μ
m so that it is 80 in a clean oven.
After prebaking at 30 ° C. for 30 minutes, exposure processing was performed using a contact exposure apparatus through a test chart reticle.
Since the resist dissolution rate varies depending on the amount of sorbitol added, the optimum exposure amount was previously measured and the optimum exposure amount was performed. [Preparation of Developer] To a 2.38% by weight aqueous solution of tetramethylammonium hydroxide (TMAH), sorbitol was added in an amount shown in Table 1 to prepare a developer, which was then subjected to a test. For comparison, the one without sorbitol added,
Moreover, the thing which added polyethylene glycol instead of sorbitol was prepared and used for the test. [Development test] After development was performed under the developing conditions of 23 ° C. and 60 seconds by the dipping method using each of the developing solutions shown in Table-1, rinse treatment was performed with ultrapure water at 120 ° C. in a clean oven. Post bake was performed for 30 minutes. After that, the film thickness reduction rate of the unexposed portion and the taper angle of the cross-sectional shape of the resist pattern after development were measured or observed. The taper angle of the sectional shape is 0.75 on the developed resist film.
The cross-sectional shape of the μm line pattern was observed and measured with a scanning electron microscope. As is clear from Table 1, the developer of the present invention sufficiently suppresses the film thickness reduction rate in the unexposed portion, and a sharp pattern line having a high taper angle can be obtained.

[0014]

[Table 1]

Example 2 Xylitol was used as sugar or sugar alcohol,
A resist pattern similar to that in Example 1 was carried out under the same developing conditions except that a developing solution prepared with a concentration of 3% by weight was used. The results are shown in Table-2.

[0016]

[Table 2]

Example 3 Sucrose was used as sugar or sugar alcohol,
A resist pattern similar to that in Example 1 was carried out under the same developing conditions except that a developing solution prepared with a concentration of 3% by weight was used. The results are shown in Table-3.

[0018]

[Table 3]

Example 4 To a 5% by weight aqueous solution of choline, sorbitol was added in an amount shown in Table 4 to prepare a developing solution, which was subjected to a test. The resist pattern used in the test was the same as that used in Example 1, and the results obtained by the same development conditions as in Example 1 are shown in Table 4.

[0020]

[Table 4]

Example 5 To a 6% by weight aqueous solution of tetraethylammonium hydroxide, sorbitol was added in an amount shown in Table 5 to prepare a developing solution, which was tested. The resist pattern used in the test was the same as that in Example 1, and the results of carrying out under the same developing conditions as in Example 1 are shown in Table-5.

[0022]

[Table 5]

[0023]

EFFECTS OF THE INVENTION The developer of the present invention sufficiently suppresses the film thickness reduction rate in the unexposed portion, enables formation of an ultrafine pattern with high resolution, and is stable with very little variation in pattern dimensions. It has an excellent effect that a good pattern profile can be provided and is extremely useful industrially.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoshi Sugawara Niigata City, Niigata City, Tayuhama, Niiwari 182 No. 182, Mitsubishi Gas Chemical Co., Ltd. Niigata Research Center

Claims (3)

[Claims] 1. A compound represented by the general formula: [(R ¹ ) ₃ NR] ⁺ · OH ⁻ (wherein R is an alkyl group having 1 to 3 carbon atoms, or a hydroxy-substituted alkyl group having 1 to 3 carbon atoms, R ¹ represents an alkyl group having 1 to 3 carbon atoms) and is a positive type containing 1 to 10% by weight of an aqueous quaternary ammonium hydroxide solution and 0.1 to 3% by weight of sugars or sugar alcohols. Photoresist developer. 2. The quaternary ammonium hydroxide represented by the above general formula is tetramethylammonium hydroxide, tetraethylammonium hydroxide or trimethyl (2-hydroxyethyl) ammonium hydroxide. The developer according to item 1. 3. The developer according to claim 1, wherein the sugar or sugar alcohol is xylitol, sorbitol, or sucrose.