JPH0562895A - Method and apparatus for developing resist - Google Patents

Abstract

PURPOSE:To accurately so develop under predetermined conditions as to form a resist pattern including an pattern by developing exposed resist in a developing tank for a predetermined time, then moving a substrate to a rinsing tank, rinsing it by using an organic solvent, and then drying it. CONSTITUTION:A method for developing a resist formed on a semiconductor wafer or a substrate 3 of a photomask after exposure comprises the steps of developing it in a developing tank 1 for a predetermined time, then moving the substrate 3 to a rinsing tank 7, rinsing it by using an organic solvent, and then drying it. For example, the substrate 3 having an exposed resist film is placed on a substrate placing base 2 in the tank 1, and developer is supplied from a developer supply tube 4 to develop it. Then, the developer is discharged, cleanser 6 is supplied from a cleanser nozzle 5 to a resist film, and removes the developer remaining on the film. Thereafter, the substrate 3 is moved to a substrate placing base 8 of the tank 7, and rinsing solution 10 is injected from a rinsing solution nozzle 9 onto the substrate 3.

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 in manufacturing a high density integrated circuit such as an LSI and a VLSI, or a photomask used for manufacturing them.

[0002]

2. Description of the Related Art In recent years, demands for higher performance and higher integration of semiconductor integrated circuits have been increasing. Therefore, instead of the conventional photolithography using ultraviolet rays, efforts are being made to establish ultrafine pattern processing technology by lithography using electron beams, soft X-rays, ion beams and the like.

At present, spraying, paddle and dipping methods are used in the developing process and the rinsing process, which are processes for forming a fine resist pattern. These temperature controls are performed only for the temperatures of the developing solution and the rinsing solution, and the atmospheric temperature of the developing tank and the like is not controlled.

[0004]

In order to enable the ultrafine lithography technique, the exposure accuracy required for the ionizing radiation exposure apparatus becomes severe, and at the same time, the resist processing process becomes very important. In particular, temperature control during development is important, and a desired resist pattern cannot be obtained unless the temperature is always kept constant. This is
Even if the accuracy of the ionizing radiation exposure apparatus is improved, the accuracy of the resulting pattern cannot be improved unless the accuracy of the processing process is improved. However, in the development of these fine patterns, the temperature of the developing solution and the like, the adjustment of the wafer or the mask before the development, and the like are still performed, but the atmospheric temperature of the developing tank or the like is not controlled.

FIG. 4 shows an example of a conventional resist developing device. The developing device 41 is provided with a substrate mounting table 32, and the substrate mounting table is attached to a rotary shaft 43. A substrate 44 such as a semiconductor wafer or a photomask on which the resist applied to the substrate mounting table is exposed is attached to the substrate mounting table, and a developing solution is supplied from a developing solution supply pipe 45.
When the development for a predetermined time is completed, the developing solution is discharged from the developing solution discharge port (not shown), the substrate mounting table is raised, the rinse solution is supplied from the rinse solution nozzle 46, and after the rinse, the rotation axis of the substrate mounting table is rotated. Spin to spin dry.

However, since the rinsing after development of the resist for electron beam drawing uses a highly volatile organic solvent, when the rinsing liquid is evaporated, the heat of vaporization is taken from the surroundings, so that the inside of the developing tank is emptied. The temperature drops. As a result, even if the temperature of the developing solution or the like is controlled, the temperature in the developing tank changes due to the heat of vaporization of the rinse solution, and the obtained resist pattern is not constant. An object of the present invention is to perform development under a certain condition with high precision in order to form a resist pattern including an ultrafine pattern.

[0007]

Means for Solving the Problems After exposing a resist formed on a substrate such as a wafer or a photomask, and developing the resist for a predetermined time, the substrate is moved to a rinse tank and rinsed with an organic solvent. The temperature of the developing tank is prevented from changing due to the heat of vaporization of the organic solvent during the rinsing. Before moving the substrate after development to the rinse tank, use a cleaning solution that has low volatility and does not lower the temperature by vaporization so that excessive development does not proceed due to the developer remaining on the substrate. Washing off is appropriate.

For a resist to which the resist developing method of the present invention can be applied, PG is used as a negative resist.
PMMA, PMI for MA, CMS, positive resist
Examples thereof include PK, and examples of the developing solution for these resists include cyclohexane, a mixed solution of methyl ethyl ketone and ethanol, a mixed solution of methyl isobutyl ketone and isopropyl alcohol, and toluene.

Further, ultrapure water, higher alcohols, esters, and low vapor pressure liquids of ketones can be used as the cleaning liquid for washing the developing liquid from the substrate after development. The rinse liquid can be appropriately selected depending on the resist and substrate used, but lower alcohols such as isopropyl alcohol and ethanol, xylene and the like can be used.

[0010]

According to the resist developing method and apparatus of the present invention, since the resist developing tank is not affected by the temperature change due to the vaporization of the rinse liquid, the development can be stably carried out.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. First, a method of forming a pattern on the resist film formed on the substrate surface with an electron beam will be described. FIG. 2 is a diagram showing a process of forming a resist pattern with an electron beam. Figure 2 (A)
As shown in, a resist film 22 is formed on a substrate 21 such as a semiconductor wafer or a photomask. Then Fig. 2
As shown in (B), the resist film 22 is irradiated with an electron beam 23 by an electron beam drawing apparatus. In the case of a positive type resist such as a polymethylmethacrylate type resist, the electron beam irradiation part 24 is altered and is changed into a form which is eluted by the developing solution. Then, as shown in FIG. 2C, the portion irradiated with the electron beam is eluted by the development to form a resist pattern.

FIG. 1 is a diagram for explaining an example of a resist film developing process. For development, as shown in FIG. 1A, a substrate 3 having an exposed resist film is placed on a substrate mounting table 2 in the developing tank 1 in which a developing tank and a rinsing tank are separately provided, and a developing solution supply pipe A developing solution is supplied from No. 4 to develop for a predetermined time.
A rotating shaft that can move up and down is attached to the substrate mounting table. After completion of development, drain the developer from the developing tank,
After the developing solution is discharged, as shown in FIG. 1B, the substrate mounting table rises, the cleaning solution 6 is supplied from the cleaning solution nozzle 5 to the resist film on the substrate surface, and remains on the resist film. The developer is washed and removed.

Next, as shown in FIG. 1C, the substrate is moved to the substrate mounting table 8 of the rinse tank 7 and the rinse liquid 10 is sprayed onto the substrate from the rinse liquid nozzle 9. After the rinsing is completed, the substrate mounting table is lowered, and the substrate mounting table is rotated at high speed by the rotating shaft 11 to perform drying. FIG. 3 is a plan view showing an example of the overall configuration of the developing device. When the substrate 3 is sent onto the loading substrate table 33 by the conveyor 35, the loading substrate table rises and the substrate is placed on the loading substrate table. Then, the transfer arm 31 of the substrate transfer device 32 is inserted into the groove 33A provided on the loading substrate table to transfer the substrate onto the transfer arm. The transfer arm is inserted into the groove 2A of the substrate mounting table 2 of the developing tank 1 to transfer the substrate to the substrate mounting table 2. When the substrate is fixed on the substrate mounting table, the developer supply pipe 4
Then, the developing solution is supplied to develop the substrate, and after the developing solution is discharged, the cleaning solution nozzle 5 moves onto the substrate to clean the substrate.

The substrate after development is transferred to the rinse tank 7 by the substrate transfer device 32, and the rinse liquid is supplied from the rinse liquid nozzle 9 to perform the rinse. After the rinsing is completed, it is transferred to the unloading substrate table 34 by the substrate transfer device, and sent to the next step by the conveyor 35.

Example 1 HEMT (High Electron Mobility Transistor: High El) using a gallium arsenide (GaAs) wafer as a wafer
electron Mobility Transisto
r) The gate pattern of the device was developed by a dipping method.

A positive resist (OEBR-1000 manufactured by Tokyo Ohka Kogyo Co., Ltd.) containing polymethylmethacrylate (PMMA) as a main component is applied to the upper surface of the gallium arsenide wafer by a spinner. After coating, prebaking was performed at a temperature of 170 ° C. for 30 minutes to form a resist film having a film thickness of 0.5 μm.

Next, in order to form a gate pattern having a width of 0.3 μm on the resist film, a predetermined portion was irradiated with an electron beam by an electron beam drawing apparatus. After drawing with the electron beam drawing device, place the substrate on the substrate mounting table of the developing tank, and adjust the mixture liquid of methyl isobutyl ketone and isopropyl alcohol with a mixing ratio of 1: 3 (volume ratio) to 23 ° C. And supplied. The wafer was immersed in the developing solution for 5 minutes for development.

After completion of the development, the substrate mounting table is raised, the used developing solution is discharged from the developing solution discharge port, and ultrapure water is supplied from the cleaning solution nozzle onto the wafer surface to remain on the wafer surface. The developer was washed away.

Next, after the wafer was moved to the substrate mounting table in the rinse tank, isopropyl alcohol was sprayed from the rinse liquid nozzle to rinse the substrate. After rinsing,
The substrate mounting table was lowered and rotated at a high speed of 1500 rpm to spin-dry the wafer. The difference in line width between the first development and the second and subsequent developments was 0.02 μm or less.

Comparative Example 1 Processing was performed in the same manner as in Example 1 except that isopropyl alcohol was sprayed as a rinse liquid onto the wafer surface immediately after development in the developing tank to perform rinsing. The difference in line width between the first and second developments was 0.03 μm.

[0021]

As described above, according to the present invention, since the developing tank and the rinsing tank are provided in separate chambers and separated from each other, the influence of the temperature drop caused by the heat absorption due to the vaporization of the rinse liquid does not affect the development. Therefore, a highly accurate resist pattern can be formed.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an embodiment of a wafer developing apparatus according to the present invention.

FIG. 2 is a diagram showing a step of forming a resist pattern with an electron beam.

FIG. 3 is a plan view showing an example of the overall configuration of a developing device.

FIG. 4 is a diagram showing an example of a conventional resist developing apparatus.

[Explanation of symbols]

1 ... Development tank, 2 ... Substrate mounting table, 2A ... Groove, 3 ... Substrate, 4
... Development liquid supply pipe, 5 ... Cleaning liquid nozzle, 6 ... Cleaning liquid, 7 ...
Rinse tank, 8 ... Substrate mounting table, 9 ... Rinse liquid nozzle, 10
... rinsing liquid, 11 ... rotation shaft, 21 ... substrate, 22 ... resist film, 23 ... electron beam, 24 ... electron beam irradiation section, 31 ... transport arm, 32 ... substrate transport device, 33 ... load substrate stand,
33A ... Groove, 34 ... Unloading substrate stand, 35 ... Conveying conveyor, 41 ... Developing device, 42 ... Substrate placing stand, 43 ...
Rotating shaft, 44 ... Substrate, 45 ... Developer supply pipe, 46 ... Rinse solution nozzle

Claims (4)

[Claims] 1. In a method of developing a resist formed on a semiconductor wafer or a substrate of a photomask after exposure, after developing for a predetermined time in a developing tank, the substrate is moved to a rinse tank to remove an organic solvent. A method of developing a resist, which comprises rinsing and then drying. 2. The method for developing a resist according to claim 1, wherein after the development is completed, the substrate is moved to the rinse tank after being cleaned with a cleaning solution having a small volatility in the developing tank. 3. A resist developing device formed on a semiconductor wafer or a photomask substrate, wherein a resist developing tank and a rinse tank are provided in separate chambers, and a rinse liquid supply device having a large volatility is provided in the rinse tank. A resist developing device characterized by the above. 4. The resist developing apparatus according to claim 3, wherein the resist developing tank is provided with a supply device of a cleaning liquid of low volatility.