JPH0250165A - Pattern forming method - Google Patents

Abstract

PURPOSE:To enhance the sensitivity at the time of development and to prevent the generation of defective definition by heating a substrate previously formed with a resist layer by application of a photoresist and supplying water to the resist layer on the substrate, then exposing and developing the resist layer. CONSTITUTION:The substrate 1 previously formed with the resist layer 2 by application of the positive type photoresist is heated. The water 6 is supplied into the resist layer 2 by immersing the substrate 1 into water and thereafter, the water on the resist layer 2 is removed. The resist layer is selectively exposed by UV light 4 and is developed. The sufficient photoreaction of the photosensitive agent is, therefore, effected at the time of exposing. The dissolving rate at the time of development is increased in this way and the generation of the defective definition is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pattern forming method used in a semiconductor manufacturing process.

[Conventional technology]

2. Description of the Related Art In recent years, with the progress of higher integration and higher density in semiconductor devices, the circuit patterns formed therein have also become finer. Furthermore, there is a growing demand for higher reliability and higher performance, making it essential to optimize manufacturing processes and improve the precision of formed patterns.

Conventionally, in order to meet such demands, the
A pattern forming method including the steps shown in 1 is employed. To explain this with reference to the figure, first, as shown in figure (a), a resist layer 2 is formed by spin-coating a positive photoresist on a substrate l made of silicon crystal, and then, as shown in figure (bl) Yohonto Plate 3
After heating the substrate 1 above, the resist layer 2 is selectively exposed to ultraviolet light 4 with a wavelength of 436 nm as shown in FIG.
A resist pattern 5 is formed on the substrate 1 by developing with an aqueous solution of (tetramethylammonium halide).

Here, during exposure, the photosensitive agent (quinone diazide type) in the resist layer 2 undergoes a photoreaction to generate indene carboxylic acid in the presence of water, and the portion that becomes indene carboxylic acid is transferred to the developer (TMAH) during development. Becomes easily soluble.

[Problem to be solved by the invention]

By the way, in the conventional pattern forming method, there is a need to suppress variations in the resist layer thickness due to changes in time from resist application to exposure, and low temperature (less than 75°C) blibrator,
In view of the reduction in resolution due to excessive residual solvent and film thinning in unexposed areas during development, the substrate 1 is heated at a high temperature (80 to 110° C.) after the formation of the resist layer 2 to evaporate the solvent in the resist layer 2. There is. For this reason, even if light is introduced into the resist layer 2 during exposure, the photoreaction of the photosensitive agent does not occur sufficiently, resulting in problems such as decreased sensitivity and poor resolution during development. That is, the solubility of exposed areas of the resist decreases during development due to decomposition of the photosensitive agent and evaporation of moisture due to high temperature heating.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a pattern forming method that can increase the sensitivity during development and can prevent the occurrence of poor resolution.

[Means to solve the problem]

The pattern forming method according to the present invention heats a substrate on which a resist layer has been formed by coating a photoresist in advance, then supplies moisture to the resist layer on the substrate, and then exposes and develops it. It is.

[For production]

In the present invention, the photosensitizer in the resist layer can be sufficiently photoreacted during exposure.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

1(a) to 1(e) are diagrams for explaining the pattern forming method according to the present invention.
The same members as those in (d) are given the same reference numerals, and detailed explanations will be omitted.

First, as shown in the figure (a), a substrate l on which a resist layer 2 is formed by spin-coating a positive photoresist in advance is heated at 80 to 110 degrees Celsius by a hot plate 3 as shown in the figure (b). Heat at a temperature of

Next, as shown in FIG. 2C, the substrate 1 is immersed in water to supply moisture 6 into the resist layer 2, and then water on the resist layer 2 is removed. After selectively exposing the resist layer 2 to ultraviolet light (wavelength 436 nm) using a reduction projection exposure device (stepper) as shown in FIG. A resist pattern 5 is formed on the substrate 1 by developing with an aqueous solution.

In this way, the resist pattern 5 according to the present invention can be formed.

Therefore, in the present invention, since the resist layer 2 on the substrate 1 is immersed in water before exposure, the photosensitive agent is sufficiently photoreacted (the quinone diazide reacts with water) by replenishing water into the resist N2. can be converted into indenecarboxylic acid in the coexistence of indene carboxylic acid.

In this example, the exposure wavelength during exposure is g-line (
436 ns), the present invention is not limited to this (for example, i-line (336 ns)).
65na), Xe-C1 excimer laser light (308
nm), KrF excimer laser light (248 nm), or ArF excimer laser light (193 nm), and of course a multi-wavelength light source may also be used as the light source.

Furthermore, in this embodiment, a dip method is used to supply moisture to the resist layer 2 on the substrate 1, but
The present invention may also be carried out by a soak method, a paddle method, or a method in which the substrate 1 is exposed to a water vapor atmosphere.

Furthermore, in the process of heating after forming the resist layer 2 on the substrate 1, as shown in FIGS. Here, numerals 7 and 8 are a decompression box and a decompression port.

Furthermore, in the present invention, even if the substrate 1 was subjected to heat treatment at a temperature of 100° C. to 150° C. after exposure and before development, the same results as in the examples could be obtained.

The specific values for the prebake temperature mentioned above are for photoresists using ethyl cellosolve acetate as the solvent, but they are also for photoresists using organic solvents with boiling points different from ethyl cellosolve acetate. Although the prebake temperature will naturally differ depending on the case, the effects of the present invention are still effective.

〔Effect of the invention〕

As explained above, according to the present invention, a substrate on which a resist layer is formed by coating a photoresist in advance is heated, then moisture is supplied to the resist layer on the substrate, and then this is exposed and developed. Therefore, by supplying water into the resist layer, the photosensitive agent can be sufficiently photoreacted during exposure, the dissolution rate during development can be increased, and poor resolution can be prevented from occurring. In addition, by heating the resist layer at low temperature under reduced pressure after forming the resist layer on the substrate, it is possible to prevent the decomposition of the photosensitizer in the resist layer and to evaporate the solvent in the resist layer. It is possible to suppress variations in the resist layer thickness due to changes in time until exposure.

[Brief explanation of the drawing]

FIGS. 1(al to Q) are diagrams for explaining the pattern forming method according to the present invention, FIGS. 2(a) to +a) are diagrams for explaining other embodiments of the present invention, and FIGS. Figure 3 (
al~(dl is a diagram for explaining a conventional pattern forming method. 1...Substrate, 2...Resist layer, 3°...Hot plate, 4...Ultraviolet light, 5...Resist pattern, 6...Moisture. Agent Masuo Oiwa Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A pattern forming method characterized by heating a substrate on which a resist layer is formed by applying a photoresist in advance, then supplying moisture to the resist layer on the substrate, and then exposing and developing the resist layer.