JPH06196397A - Method and apparatus for developing resist - Google Patents

Abstract

PURPOSE:To prevent an ultrafine resist pattern having a large aspect ratio from falling down in a developing process. CONSTITUTION:A developing solution 4 is supplied to a substrate holder 12 which is provided under heath with a vacuum suction mechanism and a rotary mechanism for a substrate 11, the latent image of a resist with which the surface of the substrate 11 has been coated is made to appear, a rinsing liquid 15 heated in advance is supplied to the surface of the resist while the substrate 11 is being heated by a heater 13 added to the substrate holder 12, the developing solution and a reaction product which remain on the surface of the substrate are removed, the substrate is dried, and ultrafine resist patterns are obtained. When the temperature of the solution is raised, its surface tension is reduced, the surface tension exerted on the resist pattern is reduced in a process in which the solution existing between the resist patterns is dried, and it is possible to prevent the patterns from falling down.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for developing an ultrafine resist pattern in a semiconductor device or X-ray mask manufacturing process.

[0002]

2. Description of the Related Art In a lithographic process generally used in a semiconductor device manufacturing process, a desired pattern is transferred or drawn on a resist having a thickness of 1 μm or more to sufficiently cover irregularities on the surface of a semiconductor substrate, and the resist pattern is used as a protective film. Then, the base is processed. However, in the photolithography technique generally used in the past, in order to resolve a fine pattern of about 0.3 μm or less with desired accuracy, the wavelength of light for transferring the figure of the photomask onto the substrate is as short as possible. It is very difficult to secure a sufficient depth of focus even when the aperture ratio of the reduction projection lens is optimized, and a technique with excellent resolution and a large depth of focus such as X-ray lithography is used. There is a need. When developing a resist that has been exposed by the conventional X-ray lithography method, a normal resist coating / developing machine is used, and a predetermined substrate is fixed to a substrate suction device equipped with a rotation mechanism by a motor. After supplying a developing solution to the resist surface and rotating the substrate appropriately to expose a desired pattern, a liquid such as pure water or alcohol is dropped and rinsed, the substrate is rotated, and the resist pattern is dried. Complete. Further, in Japanese Utility Model Laid-Open No. 63-197331, a temperature adjusting means (a spiral pipe is passed through the spin head to let a liquid flow therein) is provided in the spin head to make the liquid temperature distribution during development uniform. It is described that the pattern accuracy of the resist is improved, but the case of rinsing is not mentioned.

[0003]

However, in such a conventional developing method, even if the X-ray lithography technique is used to transfer an ultrafine pattern with desired accuracy, if the aspect ratio of the resist pattern to be formed becomes large, Regardless of the type of resist, due to the surface tension of the liquid sandwiched between the fine patterns in the rinse process of the resist pattern,
There was a problem that the resist pattern would collapse.

[0004]

In the present invention, at least one of the substrate itself and the rinsing liquid is heated to bring the surface of the substrate to a predetermined temperature for rinsing. Alternatively, after a desired resist pattern is exposed by developing and rinsing, water vapor is supplied to the resist pattern surface to heat the substrate surface and evaporate the rinse liquid. Generally, the density of a liquid is ρ, the molecular weight is M,
When the critical temperature is T _c , the surface tension γ is γ = K (ρ /
M) ^2/3 (T _c −T −δ) (K and δ are constants)
(Journal of the Chemical Society (Jo
f Chem. Soc. ), 63, 1089 (18
1993)), the surface tension of the liquid decreases as the temperature of the liquid increases, so the surface tension applied to the resist is reduced in the process of drying the liquid that has penetrated between the resist patterns, and the aspect ratio (aspect ratio) is reduced. It is possible to prevent the resist pattern from collapsing even in the case of an ultrafine pattern having a large size.

Further, as can be seen from this equation, when the temperature of the liquid is set at or near the critical temperature T _c , the surface tension becomes so small that it can be ignored. You can

[0006]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial sectional schematic view showing the structure of a resist developing apparatus according to the present invention. The substrate 11 coated with the resist to be developed is fixed to the substrate holder 12 by vacuum suction. A heater 13 and a thermocouple (not shown) are embedded in the substrate holder 12 to maintain the temperature of the substrate in a desired range, for example, 50 to 100 ° C. The developer 14 is sent from a dedicated container by a pump or compressed air, supplied to the substrate surface to expose a desired resist pattern, and then rinsed with pure water or alcohol before the developer on the resist surface dries. 15 is supplied to the surface of the substrate in the same manner as the developing solution, and the substrate is rotated by a motor to remove the developing solution and the reaction product. The rinse liquid 15 is installed in a temperature controller 16 using water or oil as a medium, and is controlled to a predetermined temperature according to the components of the rinse liquid, for example, in the range of 50 to 100 ° C. like the substrate. Although the substrate 11 and the rinse liquid 15 are both heated in this embodiment, at least one of them may be heated.

In the embodiment shown in FIG. 2, the heating of the substrate in the rinsing step is performed by the infrared lamp 21, and the heating of the rinsing liquid can be performed more effectively and at the same time when a large number of substrates are continuously treated. Moreover, there is an advantage that the rise of the substrate temperature in the next substrate developing step can be suppressed.

In the third embodiment, substrate holders for development and rinsing are independently provided in order to avoid temperature rise in the development process when substrates are continuously processed. In that case, it is possible to raise the temperature of the substrate and the rinse liquid only in the rinse step.

In the fourth embodiment, after a desired resist pattern is exposed by a normal developing / rinsing process, the surface of the substrate is heated while spraying steam onto the surface of the resist pattern so that the resist pattern remains between the resist patterns. The rinse liquid is gradually evaporated while being kept at a high temperature.

[0011]

In such a resist developing / rinsing method, since the rinse liquid is supplied to the resist surface before the developing liquid is dried, the resist pattern is not collapsed at least due to the surface tension of the developing liquid. In the rinsing step, the substrate surface is preheated to a predetermined temperature, or the substrate is heated while supplying the water vapor to the resist pattern surface while the rinse liquid remains on the resist pattern surface after the rinse is completed. Is gradually evaporated, the surface tension of the rinse liquid is reduced to a negligible amount when the rinse liquid is evaporated from the resist pattern surface. As a result, it is possible to prevent the collapse of the ultrafine resist pattern having a large aspect ratio.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a second embodiment of the present invention.

[Explanation of symbols]

 11 substrate 12 substrate holder 13 heater 14 developer 15 rinse liquid 16 temperature controller 21 infrared lamp

Claims (6)

[Claims] 1. A method of developing a resist film coated on a surface of a substrate to expose a desired resist pattern and then supplying a rinse liquid to wash the substrate itself or at least one of the rinse liquids. A resist developing method in which the substrate surface is heated and washed while being heated. 2. A resist film applied on the surface of a substrate is developed.
A resist developing method comprising: rinsing to expose a desired resist pattern, and then heating the substrate surface while supplying steam to the resist pattern surface to evaporate the rinse liquid. 3. The resist developing method according to claim 1, wherein the substrate surface is heated to a temperature close to the critical temperature of the rinse liquid. 4. A substrate holder provided with both a substrate heating and rotating mechanism, and a mechanism for supplying a developing solution and a rinse solution which has been heated to a predetermined temperature to the surface of the substrate held by the substrate holder. A resist developing device characterized by the above. 5. The resist developing apparatus according to claim 4, wherein a substrate heating mechanism is provided independently. 6. A substrate holder provided with a rotating mechanism, a mechanism for supplying a developing solution and a rinsing solution to the surface of the substrate held by the substrate holder, and means for heating and drying the substrate surface while supplying water vapor. A resist developing device having.