JP3276015B2 - Developing method and developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing method and a developing apparatus for forming a resist pattern when manufacturing a high-density integrated circuit such as an LSI or a super LSI, or a photomask used for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, demands for higher performance and higher integration of semiconductor integrated circuits and the like have been further increased. For this reason, efforts are being made to establish an ultra-fine pattern processing technique by lithography using electron beams, soft X-rays, ion beams, or the like, instead of conventional photolithography using ultraviolet rays.

At present, a developing process for forming an ultrafine resist pattern includes a spraying method, a paddle method, and a dipping method. However, in the dip development, only the temperature of the developing solution and the rinsing liquid, the temperature of the substrate before the development, and the environmental temperature of the developing device are controlled, and the temperature control during the development is hardly performed. . Further, for sprays and paddles, it is almost impossible to control the temperature during development.

[0004]

In order to enable ultra-fine lithography technology, the exposure accuracy required for an ionizing radiation exposure apparatus becomes severe, and the resist process becomes very important. In particular, temperature control during development is important, and unless the temperature is constantly maintained, a desired resist pattern cannot always be obtained. This means that even if the accuracy of the ionizing radiation exposure apparatus is improved, the accuracy of the resulting resist pattern will not be improved unless the accuracy of the developing process is improved. But,
In the development of these ultra-fine patterns, as described above, only the temperature control of the developer before development and the seasoning of the substrate before development are performed, and the temperature control of the developer during development is hardly performed. Not done. The dip developing method, which can only perform temperature control during development, requires a large amount of developing solution, and thus is not suitable for manufacturing LSIs and the like.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has as its object to stabilize the temperature of a developing solution for forming a resist pattern including an ultrafine pattern easily and accurately, and to achieve the required temperature. An object of the present invention is to provide a developing method and a developing apparatus which can perform development with a minimum amount of a developing solution.

[0006]

In developing an exposed substrate, the temperature of the developing solution is not constant due to heat of vaporization or the like. For this purpose, in the present invention, the developer is interposed between the substrate and the top plate to reduce the contact area with the air and reduce the above-mentioned temperature change. Then, by flowing a constant-temperature circulating liquid at a controlled temperature into the substrate holding table and the top plate, the temperature of the developing solution is further stabilized, and the accuracy of each operation is improved.

Further, since the developer sandwiched between the substrate and the top plate is supported only by the surface tension, the amount of the developer is extremely small as compared with the dip development in which the temperature can be controlled during the development.

That is, the developing method of the present invention is a developing method of developing a substrate having a photosensitive layer exposed to ionizing radiation by contacting the substrate with a developing solution. Pour a constant temperature circulating fluid into the plate,
While keeping the temperature of the substrate holding table and the top plate constant, the top plate is brought close to the substrate in parallel, then a developing solution is sandwiched between the substrate and the top plate, and the developing temperature is kept constant to expose the substrate with the developing solution. Develop the layer, retract the top plate after development, flow a constant temperature circulating liquid into the substrate holder, spray rinse solution onto the developed substrate while maintaining the temperature of the substrate holder constant, and rinse. Is performed.

In this case, it is desirable that the developer interposed between the substrate and the top plate is supported by surface tension.

[0010]

[0011]

[0012]

[0013]

In the developing method of the present invention, a constant-temperature circulating liquid is flowed into the substrate holding table and the top plate which are in contact with and held on the entire surface of the substrate, and the temperature of the substrate holding table and the top plate is kept constant, and The developer is sandwiched between the substrate and the top plate, the developing temperature is kept constant, the photosensitive layer of the substrate is developed with the developer, the top plate is retracted after the development, and the substrate is held. The rinsing liquid is sprayed on the developed substrate to perform the rinsing cleaning while the constant temperature circulating liquid flows through the table and the temperature of the substrate holding table is kept constant. And the temperature change due to heat of vaporization is reduced, and the accuracy of the developed photosensitive pattern is improved. Also, since the developer is sandwiched between the substrate and the top plate after the top plate is brought close to the substrate in parallel, the waste of the developer is minimized without waste.

Further, by flowing a constant-temperature circulating liquid into the substrate holder and the top plate to keep the temperature of the substrate holder and the top plate constant, the developer is further kept constant and developed. The accuracy of the photosensitive pattern is further improved. In addition, since the rinsing step is started after the development without moving the substrate, the photosensitive pattern does not dissolve during the movement of the substrate. Further, since the rinsing is performed while keeping the temperature of the substrate holding table constant, the temperature of the substrate holding table does not drop even by the vaporization and absorption of the rinsing liquid, and the development of the next substrate is not affected by the environmental temperature.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the developing method and apparatus of the present invention will be described below with reference to the drawings. FIG. 1 shows a cross section of the developing device of the embodiment of the present invention, FIG. 2 shows a developing process using this developing device, FIG. 3 shows a rinsing process using this developing device,
Shown respectively. FIG. 5 shows a conventional dip developing machine. In the figure, 1 is a substrate for developing a resist film, 2 is a top plate for sandwiching a developer between the substrate 1 and 3 is a developer supply pipe provided at the center of the top plate 2 and 4 is a substrate 1 to be developed. , A developing tank accommodating the substrate holding table 4 therein, a developer 6, and a constant-temperature circulation 7 circulated inside the top plate 2 and the substrate holding table 4. Reference numeral 8 denotes a rinsing liquid for rinsing the developed substrate, and reference numeral 9 denotes a rinsing nozzle for spraying the rinsing liquid 8. In the case of the conventional dip developing machine shown in FIG. 5, similar components are indicated by adding dashes to the reference numerals in FIGS.

In a conventional dip developing machine, as shown in FIG. 5, a substrate holder 4 'arranged in a developing tank 5' is provided.
The developing solution 6 'is supplied from the developing solution supply pipe 3' into the developing tank 5 ', and the substrate 1' is lowered by moving the substrate holder 4 'into the developing tank 5'. The developer is immersed in the developing solution 6 'accumulated in the developer and developed. On the other hand, in the developing device according to the present invention, as shown in FIG. 1, the top plate 2 integrally having the developer supply pipe 3 is arranged above and below the substrate holding table so as to be able to move up and down. As shown in FIG. 2, the top plate 2 comes close to the substrate 1 on the substrate holding table 4. The approach distance is set to such an extent that the developer 6 is maintained between the substrate 1 and the top plate 2 by surface tension. Therefore, the developing solution 6 necessary for developing the substrate 1 is as shown in FIG.
Only a small amount is required compared to a dip device such as

A constant temperature circulating liquid 7 flows in the substrate holding table 4 and the top plate 1 as shown by arrows in the drawing, so that the developing temperature is always kept constant and the resist pattern is precisely formed. Will be kept.

Next, a process of forming a resist pattern on a substrate by using the apparatus of this embodiment will be described with reference to FIG. 4 showing a resist pattern forming process and FIGS. In the following description, GaAs is used as the substrate.
HEMT (High Electron Mobility Transistor: High Electron Mobility)
This is an explanation of an example in which the formation of a gate pattern of a transistor device is developed using the developing device of the present invention.

First, before describing the developing process, a process of forming a resist film 21 on the substrate 1 and an electron beam drawing process for forming a resist pattern will be described.

On the upper surface of the substrate 1 as shown in FIG.
As shown in FIG. 1B, a positive resist containing polymethyl methacrylate as a main component (trade name: Tokyo Ohka Co., Ltd.)
OEBR-1000) is applied by a spinner. After the application, the resist film 21 is baked at a temperature of 170 ° C. for about 30 minutes to form a resist film 21 having a thickness of 0.5 μm.

Next, as shown in FIG. 1C, in order to form a gate pattern having a width of 0.3 μm on the resist film 21, a predetermined amount of the resist film 21 is formed using an electron beam 22 of an electron beam lithography apparatus. The portion 23 is exposed and deteriorated. A resist pattern is obtained from the exposed resist film 21.

After completion of drawing the resist pattern by the electron beam 22, the drawn resist pattern is developed by using the developing device shown in FIG. As shown in FIG. 1, a substrate 1 on which a resist pattern has been drawn by an electron beam 22 is fixed on a substrate holding table 4 of a developing device. After the fixation, the top plate 2 descends from above, and the developing solution 6 supplied from the developer supply pipe 3 is placed on the substrate 1 to a distance sufficient to maintain the surface tension between the substrate 1 and the top plate 2. Get closer. Then, the developer 6 is supplied from the developer supply pipe 3.
Supply. The situation at this time is as shown in FIG. The developer 6 is a mixed solution of methyl isobutyl ketone and isopropyl alcohol at about 23 ° C. at a mixing ratio of 1: 3. The altered resist film 23 is coated with the developer 6
Dissolve in. When the resist film 23 dissolves, heat of dissolution may be generated. However, since the constant temperature circulating liquid 7 flows in the substrate holding table 4 and the top plate 2, the developing solution 6 can be developed under a constant condition even with an extremely small amount of the developing solution 6. Can be done.

The substrate 1 is subjected to a developing process for about 5 minutes. After the completion of the development process, as shown in FIG. 3, the top plate 2 is retracted, and the rinse nozzle 9 descends instead, and the rinse liquid 8 is sprayed from the nozzle 9 onto the substrate 1 after development, and
Rinse for 2 seconds.

At this time, the sprayed rinsing liquid 8 causes vaporization heat absorption, and this heat absorption may affect the development line width. As a prominent example, this heat absorption lowers the temperature of the developing tank 5, and the developing tank 5 drops below the environmental temperature.
There is a problem that it takes time until the temperature of the developing tank 5 is recovered in the next development. However, using the device of the present invention,
Since the constant-temperature circulating liquid 7 flows as described above, the temperature of the substrate holder 4 does not decrease even by the vaporization and absorption of the rinsing liquid 8, and the next development of the substrate 1 is not affected by the environmental temperature. In addition, since the amount of the developer 5 is small, the temperature can be easily maintained, and the area of the developer 5 in contact with air is small, so that the developer 5 is hardly affected by a change in environmental temperature.

After rinsing, a resist pattern 21 is formed on the substrate 1 as shown in FIG.

As described above, according to the developing method and the developing apparatus of the present invention, compared to the conventional one, the developing method is more resistant to environmental temperature changes and the amount of the developing solution used can be reduced.

Although the developing method and the developing device of the present invention have been described based on the embodiments, the present invention is not limited to these embodiments, and various modifications are possible.

[0028]

As is apparent from the above description, according to the developing method of the present invention, the constant temperature circulating liquid is flowed into the substrate holding table and the top plate, which contact and hold the entire surface of the substrate. While keeping the temperature of the top plate constant, bring the top plate close to the substrate in parallel, then sandwich the developing solution between the substrate and the top plate, and maintain the developing temperature constant to develop the photosensitive layer of the substrate with the developing solution. After the development, the top plate is retracted, a constant temperature circulating liquid is flowed into the substrate holder, and the temperature of the substrate holder is kept constant.
Rinsing is performed by spraying the rinse solution on the substrate after development, so that the development temperature is constant, the contact area of the developer with air is reduced, the temperature change due to heat of vaporization is reduced, and the photosensitive pattern to be developed is reduced. The accuracy of is improved. Also, since the developer is sandwiched between the substrate and the top plate after the top plate is brought close to the substrate in parallel, the waste of the developer is minimized without waste.

Further, by flowing a constant-temperature circulating liquid into the substrate holder and the top plate to keep the temperature of the substrate holder and the top plate constant, the developer is further kept constant and developed. The accuracy of the photosensitive pattern is further improved. In addition, since the rinsing step is started after the development without moving the substrate, the photosensitive pattern does not dissolve during the movement of the substrate. Further, since the rinsing is performed while keeping the temperature of the substrate holding table constant, the temperature of the substrate holding table does not drop even by the vaporization and absorption of the rinsing liquid, and the development of the next substrate is not affected by the environmental temperature.

As described above, according to the present invention, a change in the temperature of the developing solution due to an extrinsic temperature change during the development can be suppressed, and a desired development result can be stably obtained. Also, the amount of developer used can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a developing device according to an embodiment of the present invention.

FIG. 2 is a view showing a developing process using the developing device of FIG. 1;

FIG. 3 is a view showing a rinsing step using the developing device of FIG. 1;

FIG. 4 is a view for explaining a resist pattern forming step.

FIG. 5 is a sectional view of a conventional dip developing machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Top plate 3 ... Developing liquid supply pipe 4 ... Substrate holder 5 ... Developing tank 6 ... Developing liquid 7 ... Constant temperature circulating liquid 8 ... Rinsing liquid 9 ... Rinsing nozzle 21 ... Resist film 22 ... Electron beam 23 ... Transformed resist film

Claims (2)

(57) [Claims] 1. A developing method for developing a substrate having a photosensitive layer exposed to ionizing radiation by bringing the substrate into contact with a developing solution, comprising: a substrate holding table that contacts and holds the entire surface of the substrate;
Constant temperature circulating fluid to keep the temperature of the substrate holder and the top plate constant.
While keeping the substrate is parallel to close the top plate to sandwich the developer then <br/> substrate and the top plate, keeping the developing temperature constant
Develop the photosensitive layer of the substrate with the developing solution. A developing method comprising performing rinsing cleaning by spraying on a substrate. 2. The developing method according to claim 1, wherein the developer sandwiched between the substrate and the top plate is supported by surface tension.