JPH0754795B2 - Resist development method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for developing an ultrafine resist pattern mainly used in a semiconductor device manufacturing process or the like.

[0002]

2. Description of the Related Art Generally, in a lithography process used in a semiconductor device manufacturing process, a desired pattern is transferred or drawn on a resist coated on the surface of a semiconductor substrate, and a photosensitive region or a non-exposed region is removed with a developing solution to form a resist pattern. Then, the resist surface was washed with a rinse liquid, and the liquid rinse liquid was dried under normal pressure to obtain a desired resist pattern. For example, a paddle developing method using a spinner is usually used in a production factory.The developing solution is dropped on the wafer adsorbed on the spinner and held for a certain period of time, and then the spinner is rotated at a low speed to scatter the developing solution. Then, the rinse liquid was continuously dropped sufficiently onto the wafer surface in a wet state, and the rinse liquid was completely spattered and dried by rotating at a high speed to obtain a desired resist pattern.

[0003]

A fine pattern having a high aspect ratio can be formed by using a lithography method having an excellent resolution and a large depth of focus, such as SR lithography. However, when the development is performed by the conventional method after the exposure, the surface tension of the rinse liquid acts on the resist pattern during the drying process of the rinse liquid, causing the pattern to collapse, especially in a fine pattern.

[0004]

In the developing method of the present invention, after cleaning the resist surface with a rinse liquid, the wafer is cooled to freeze the rinse liquid without exposing the surface of the resist pattern on the liquid surface, and the pressure is reduced under reduced pressure. The surface tension of the rinse solution is prevented from acting on the resist pattern by sublimation by, and the collapse of the pattern is prevented. This method is particularly effective when pure water having a large surface tension is used as the rinse liquid.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram simply showing a resist developing method according to the present invention. After exposing a predetermined area 2'of the resist 2 applied on the surface of the wafer 1, the developer 3 is dropped on the surface to dissolve the photosensitive area in the positive resist and the non-exposed area in the negative resist. Then, the desired resist pattern 4 is exposed. Then rinse 5
The wafer surface is washed with, and the rinse liquid is frozen (5 ′) when the surface of the resist pattern is wet, and sublimated under reduced pressure to dry the surface of the resist pattern.

FIG. 2 shows a resist developing apparatus according to the present invention. The wafer 6 coated with the resist to be developed is fixed to the holder 7 by vacuum suction. After the developer 8 is supplied to the surface of the substrate to expose the resist pattern, the substrate is rotated while supplying the rinse liquid 9 such as pure water to the surface of the substrate to remove the developer and the reaction product. After that, the wafer 6 is transferred to the inside of the chamber 10 while the surface of the wafer is wet with the rinse liquid, and is fixed on the stage 11 having a heating / cooling mechanism. The cooling medium 12 is circulated through the stage to cool the wafer to a temperature below the freezing point of the rinse liquid to freeze the rinse liquid. Then vacuum pump 14 inside the chamber.
Then, the pressure is reduced to a pressure not higher than the triple point of the rinse liquid, and the wafer is heated to room temperature with the heater 13 in the reduced pressure state to sublimate the frozen rinse liquid to obtain a desired resist pattern.
Further, if the inside of the chamber is sufficiently decompressed after freezing the rinse liquid, the frozen rinse liquid is sublimated and the desired resist pattern can be obtained without raising the temperature.

[0007]

As described above, in the developing method of the present invention, since the surface tension of the rinse liquid does not act on the resist pattern, it is possible to prevent the fine pattern from collapsing in the developing process.

[Brief description of drawings]

FIG. 1 is a process drawing showing an example of a developing / rinsing method of the present invention in process order.

FIG. 2 is a schematic view of an apparatus showing an example of a developing apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 wafer 2 resist 2'photosensitive resist 3 developing solution 4 resist pattern 5 rinsing solution 5'frozen rinsing solution 6 wafer 7 holder 8 developing solution 9 rinsing solution 10 chamber 11 stage 12 refrigerant 13 heater 14 vacuum pump

Claims (1)

[Claims] 1. In the development of a resist film on which a predetermined pattern is transferred, the surface of the resist pattern exposed with a developing solution is washed with a rinse solution and then the surface of the resist pattern.
A resist developing method, characterized in that the rinsing liquid is frozen without being exposed to the liquid surface , sublimated under reduced pressure, and the surface is dried.